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legal scholars, scientists, and commentators lament the onslaught of behavioral genetics and neuroscience in the criminal courtroom. fueled largely by anecdotal evidence about the use of bioscience in criminal cases, or media reports of high - profile cases, there is a growing belief that neuroscience has become a mainstay of the us criminal justice system. and while scholars increasingly self - identify as part of the growing fields of law and neuroscience or law and the biosciences, to date only small - scale studies have been conducted on the use of neuroscience and behavioral genetics in the us criminal justice system. one recent study involved an empirical analysis of just those cases in which neuroimaging had been reported in a judicial opinion, with 23 analysed cases. other studies have qualitatively, but not quantitatively, assessed the use and impact of neurobiological evidence in criminal law, again relying almost exclusively on discussion of that evidence in published judicial opinions. any examination of the impact of behavioral genetics and neuroscience on the us criminal justice system must begin with a more accurate understanding of how that evidence is currently being used. to better ground the interest and commentary on the use of neuroscience and behavioral genetics (hereinafter neurobiological evidence) in criminal law, this article summarizes some findings from the widest scale empirical study on the use of neurobiological evidence in us criminal law to date. over the past decade, over 1585 judicial opinions issued between 2005 and 2012 discuss the use of neurobiological evidence by criminal defendants to bolster their criminal defense. in 2012 alone, over 250 judicial opinions more than double the number in 2007cited defendants arguing in some form or another that their brains made them do it. approximately 5 per cent of all murder trials and 25 per cent of death penalty trials feature criminal defendants making a bid for lower responsibility or lighter punishment using neurobiological data. while these claims often overstate the science, used responsibly neurobiological evidence has the potential to improve the accuracy and decrease errors in the criminal justice system. much of the scholarship on neurobiological evidence in criminal law has focused exclusively on either behavioral genetics or neuroscience. first, scientific developments increasingly link findings from behavioral genetics to neural correlates. as a result, the emerging scientific inquiry into human behavior is trending toward a neurobiological approach over a purely genetic or neuroscientific one. moreover, the research in these fields foretells a more integrated future in human behavioral research, whereby genetics and neuroscience are linked rather than compartmentalized. as one telling example, the march 2010 issue of the seminal journal behavior genetics dedicated a special issue to pathways between gene, brain, and behavior. the 15 articles included in the volume represented the diversity of methodologies applied to the complexity of pathways linking genes, brain, and behavior. the introductory chapter concluded that the breadth of studies proves that tracing the pathways between biology and behavior requires expertise in genetics, neuroscience, psychology, and psychiatry. the integration is reflected in the use of behavioral genetics and neuroscience in the criminal justice system. legal practitioners take a multifaceted approach to characterizing defendants behaviors by introducing genetic, neurological, and environmental contributions. monamine oxidase a (maoa), the first gene environment interaction associated with temperament and antisocial behavior, is a well - studied example. although maoa was first characterized as a genetic polymorphism, which together with environmental triggers is associated with behavioral variation in antisocial personality, more recent studies link the genetic and neurological correlates of maoa. joshua buckholtz. published a study utilizing a combined genetic and imaging approach to the study of maoa, which implicates a neural circuit for variation in human personality under genetic control. already, a multifaceted criminal defense using maoa genotyping, and neuroimaging has been introduced into criminal cases. even assuming differences in scientific methodology and results between behavioral genetics and neuroscience, the substantive legal claims raised are nearly identical when either science is used in a criminal case. as a result in this study sample, anytime behavioral genetics was raised ; a neuroscientific claim was also advanced. while neuroscience by far dominates the scientific evidence introduced, the results here include cases where both neuroscience and behavioral genetics are sometimes introduced. with a few notable exceptions, scientists are on the sidelines of these developments in criminal law. publicly engaged scientists often decry the use of neurobiological evidence criminal law, and call for an outright ban on its use. this is driven in part by concerns about significant methodological obstacles in the study of human behavior. what does aggression mean ? does criminal behavior include petty crimes as well as violent ones ? even when scientists do establish a robust and consistent definition for a specific trait they face difficulties in finding reliable measures of those traits in a manner that satisfies acceptable standards of scientific validity, including reproducibility. measuring complex behavioral traits has been difficult, and as a result difficult to replicate in other studies as well. research into the biological contributions to human behavior face an additional complication : behaviors, which are complex traits and involve multiple genes, regulated by widely varying cellular and neurological mechanisms, are subject to substantial environmental influence. these scientific concerns underscore the study of complex behavioral traits of interest to the criminal law. criminal. any scientific claim about the biological contributions to criminal conduct begins with a narrower focus on the behaviors often implicated by criminal conduct including violence, aggression, and drug and alcohol abuse. studies of those traits and related traits have likewise yielded only preliminary data that have yet to be well replicated or understood. but decrying the use of neurobiological evidence in criminal law seems both futile and counterproductive ; neuroscience is already entrenched in the us legal system. and used appropriately, it holds promise of improving decision - making in law. but just as neuroscientists go too far in calling for an outright ban, defense attorneys are guilty of overstating the science. criminal defendants regularly use neuroscience at every stage of the criminal process, from pretrial, to trial, and sentencing determinations. prosecutors, too, have seized upon cognitive neuroscience to argue that defendants are incorrigible and should be given longer sentences. rather than standing in the way, neuroscientists should educate the public about the responsible use of neuroscience in the courtroom. to empirically ground the dialog about the use of neuroscience in the us criminal justice system, this article is the first comprehensive empirical study of the use of neurobiological evidence in us criminal justice cases. drawing from data analysed from 1585 coded criminal cases, in which judicial opinions were written and published in westlaw during 200512, this study presents some surprising results and trends in emerging use of neurobiological evidence in criminal law. the cases collected, coded, and analysed in this study demonstrate a rising use of neurobiological research in criminal law. that use continues to be haphazard, ad hoc, and often ill conceived. while scientists caution that the neurobiological evidence at issue is weak, particularly for making claims about individuals rather than studying between - group differences, their cautionary advice has largely gone unheeded. even the gravest decisions, including assessments bearing on deservingness for capital punishment, are beginning to turn on this research. defense attorneys have introduced behavioral genetics and neuroscience in attempts to exculpate criminal defendants, to bolster preexisting legal defenses, and to mitigate defendants ' culpability and punishment. prosecutors have seized upon the double - edged potential of a claimed neurobiological evidence to denigrate defendants ' characters and to demonstrate defendants ' likely future dangerousness. as the science continues to develop, its potential use in criminal investigations, interrogations, and predictions of dangerousness will undoubtedly rise. the discovery of more specific biological and neurological contributions to violence, aggressiveness, impulsivity, substance abuse, even though highly contestable and indeterminate as a scientific matter, has foreshadowed an inevitable reexamination of the us criminal justice system. indeed, the united states supreme court has already become involved in evaluating the relevance of neurobiological evidence to criminal culpability : in september of 2006, it granted certiorari to address, in part, whether a defendant 's genetic predisposition to violence should inform whether he should be sentenced to death for first - degree murder. liberty, justice, privacy, and the structure and purpose of the us criminal justice system are all at issue. a careful and systematic study of the use, perception, current and likely impact of neurobiological evidence on criminal law is essential before its application further expands. seventeen law students and three undergraduate students were trained over time on a coding book developed by the author that included 84 variables. the students included second and third - year law students, with varying scientific background. the 84 variables are detailed in the coding book with specificity to ensure uniform coding. these variables included, for example, purely identifying information about the case, the purpose for which the behavioral genetics or neuroscience evidence was introduced, the outcome of the case (successful or unsuccessful for the criminal defendant), the state where the case was heard, and the types of attorneys or representation present. coders were first given the coding book, and asked to code a set of four test cases. after coding the four cases, they were trained in detail on the meaning of each variable through an intensive in - person training session with farahany. they were then given a second set of test cases to code, and discrepancies were reviewed and discussed with farahany. coders were then were given cases in sets of 10 to code, which were spot - checked by farahany. there was less than 5 per cent disagreement between coders, and typically pertaining only to the nature of the claim raised. farahany reviewed all coding with spot - checking, and resolved any conflicts that arose between the coders. cases in the study were selected from searches of the westlaw legal database using the keywords and variations on the words : neuroscience, frontal lobe, hereditary, head injury, pet scan, eeg, fmri, ct scan, brain disorder, cognitive impairment, meg, nirs, brain scan, brain, diffusion tensor, heritable, hereditary, genetic, biological, memory, frontemporal, and qeeg. the westlaw databases used included all us supreme court, all federal court and all state court. the broad search terms used search yielded over 10,000 opinions per year, which were then scanned for relevance. after excluding cases that did not bear on the use of neurobiological evidence by a criminal defendant, 1585 cases were included in the study, and all opinions in those cases majority, plurality, concurring, and dissenting opinions for a total of 1800 judicial opinions, were coded. cases in which the scientific evidence focused on the victim or forensic identification were excluded. westlaw 's inclusion criteria for judicial opinions are proprietary, unpublished, and may have changed during the study time period. these variations may account for some of the year - to - year differences in the number of opinions discovered. moreover, the cases contained therein are primarily appellate opinions, since trial opinions at the state level are often jury verdicts without written judicial opinions. consequently, the opinions coded may reflect defendants failed attempts at using neuroscientific evidence at trial, failure to by defense counsel to investigate or introduce neurobiological evidence at trial, or newly discovered evidence on appeal. the sample may be skewed toward defendants who have already fared poorly in the criminal justice system with their claims. moreover, more than 90 per cent of criminal cases in the united states never go to trial. most individuals who are charged with a crime forego their constitutional right to a trial and plead guilty in exchange for a plea agreement. of those cases that do go to trial, while many are appealed, many more are not. of cases that are appealed, there are narrow legal grounds available for overturning a conviction or setting aside a sentence and procedurally the cases must be raised in that manner. moreover, investigation into neurobiological contributions to criminal behavior can be costly. in cases where the defendant has adequate resources, or able to secure resources from the state, or as pro bono services these skews may mean the sample of cases here underreports the actual use of neuroscience in the criminal courtroom. and that the cases are skewed toward unsuccessful use of neurobiological evidence. hence, while the present empirical study significantly advances the ethical, legal and social discussions with respect to the use of neurobiological evidence in us criminal law, it is still a narrow view of the overall issue most studies on the use of neurobiological evidence in criminal cases claim it 's used almost exclusively to mitigate capital punishment and with limited success. the findings discussed herein suggest both a broader and potentially more successful use of neurobiological evidence in us criminal law. significant differences by state also appear, including the extent to which the evidence has been introduced, and the ultimate success of that evidence. these differences can be explained in part by population differences, and varying legal regimes across states (eg the availability of capital punishment, the type of insanity defense available in the state, or the relevance of a diminished capacity defense). importantly, neurobiological evidence is being used for purposes not yet discussed or analysed by scholars. for example, while many scholars have discussed the implications of using neurobiological evidence for mitigation of criminal punishment, virtually no author has discussed the implications of using it to assess the competency of a criminal defendant. and yet the empirical analysis herein illustrates that the second most common use of biological neurobiological evidence in criminal cases is to challenge competency. the implications of this use, and the relevance of behavioral genetics and neuroscience to competency determinations, are critical areas for further exploration. finally, while attempts to introduce neurobiological testimony have been relatively unsuccessful to date, the attempts may have been more successful than most scholars believe. depending on the type of claim that a criminal defendant raises, testimony by an expert on the matter may serve as powerful evidence that impacts the outcome of the case for the defendant. in short, the fundamental assumptions guiding the current ethical, legal and social inquiry into the use of neurobiological evidence in criminal law are limited and potentially flawed. the goal of this study is to broaden the dialog and bring empirical evidence to bear on the discussion. the number of judicial opinions discussing the use of neurobiological evidence by criminal defendants is increasing year over year (see graph 1). contrary to popular belief, many of these cases are not capital homicide cases (the prosecutor did not seek the death penalty, or it was unavailable as a sentence in that jurisdiction). defense attorneys are introducing neurobiological evidence across the board in serious felony cases, and not just in bifurcated capital sentencing hearings following a conviction of first - degree murder. (homicide (capital) are murder cases in which the prosecutor sought the death penalty. homicide (not capital) are some degree of homicide (murder, manslaughter) cases in which the death penalty was not at issue. other felony cases are those in which the defendant was not charged with homicide.) this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse, please contact the rights holder. what started as about 100 judicial opinions per year discussing neurobiological evidence in criminal law in 2005 climbed to around 250300 opinions in 2012. opinions earlier in the study often discuss neurobiological evidence as part of a laundry list of other types of scientific evidence introduced. in later opinions, judges spilled substantial ink discussing the neurobiological evidence often in significant detail and with citations to scientific literature and the experts who testified in the case (see graph 2). this suggests a shift in both the frequency and the nature of how such evidence is being evaluated by judges and juries in criminal cases. substantive is one paragraph or more of the opinion discussing the neurobiological evidence introduced by a criminal defendant.) this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse one surprising result is how broadly neurobiological evidence is being by criminal defendants at trial. the popular mantra in academic circles is that the use of neurobiological evidence is primarily a phenomenon limited to capital cases, as mitigating evidence for sentencing. in the sample of opinions studied here, only about 40 per cent of the cases were capital, and a staggering 60 per cent of cases were other serious felony cases. drilling down further by looking at the most serious crime a defendant was charged with in the sample, it becomes clear that across felony cases neurobiological evidence is being used as part of criminal defenses (see graph 3). most serious offense charged with when neurobiological evidence raised in non - capital cases, 200512. an evaluation of the most serious criminal charge (per case) that the defendant was charged with to illustrate the range of felony cases impacted by neurobiological evidence. this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse in the 60 per cent of non - capital cases where neurobiological evidence is introduced, neurobiological evidence is also introduced in drug possession and trafficking cases, violent assaults, robbery, fraud, and more. although this sample likely underrepresents the prevalence of neurobiological evidence used in criminal cases due to the methodological barriers discussed supra, a conservative estimate based on this sample alone is that neurobiological evidence is introduced in at least five to 6 per cent of murder trials in the usa, and 14 per cent of other felony offenses. one explanation for differences in the findings of this study versus other empirical studies on the use of neurobiological evidence is a difference in what the neurobiological evidence includes medical history (such the use of past medical records or medical history of head injuries or brain damage), neuropsychological testing (through interviews, battery of testing, and/or evaluation of the defendant), brain scanning of the defendant, or assertions that the defendant suffers from brain or head injury. notably, only about 15 per cent of the cases where neurobiological evidence was raised in the sample had any form of brain scanning discussed in the opinion (see graph 4). a large proportion of the cases (nearly 40 per cent) have no discussion of neurological testing in the opinion, even though the defendant staked their defense in part on a claim that his brain made him do it. of course, it 's entirely possible that the judicial opinion did not discuss the specifics of testing that actually was introduced in the criminal case, so this is a conservative estimate of testing introduced. (the number of opinions per year in which each time of neurobiological testing is discussed. interview+ = neuropsychological testing / evaluation, as well as medical or other history of head / brain trauma ; scan+ = some form of brain scanning evidence, neuropsychological testing / evaluation, as well as medical or other history of head / brain trauma ; history only = medical or other history of head / brain trauma but no other form of testing discussed in opinion ; no neurotesting = no discussion of any form of neurological testing introduced in opinion.) this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse, please contact the rights holder. in the 15 per cent of cases that included a discussion of brain scanning in the opinion, the type of scanning was most often mri or cat scans, rather than more sophisticated functional neuroimaging such as eeg, spect, or fmri scanning (see graph 5). functional magnetic resonance imaging (fmri) was discussed in about 2 per cent of the 15 per cent of scanning cases, but in each of the cases the fmri evidence was not admitted into the case for further consideration because of concerns about scientific reliability, credibility, or relevance. (in the opinions where neuroimaging was introduced, the type of neuroimaging. spect = single - photon emission computed tomography ; qeeg = quantitative electroencephalography ; fmri = functional magnetic resonance imaging ; unknown = brain scanning discussed but type not mentioned ; beam = sometimes known as qeeg, brain electrical activity mapping ; cat = computed tomography ; eeg = electroencephalography ; mri = magnetic resonance imaging ; pet = positron emission tomography.) author, 2016. this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse one surprising finding is the extent to which neurobiological evidence is used in pretrial proceedings (see graph 6). in pretrial proceedings, the subjective mental state and competency of the defendant can be contested. at this phase of trial, neurobiological evidence may offer a way to improve subjective competency evaluations. judges typically engage in a colloquy with a defendant and rely upon their own perception of the defendant, together with mental health evaluations, to rule on the defendants competency. neuropsychological testing, neurological history, and neuroimaging may meaningfully and appropriately improve such judgments and perceptions. distribution of neurobiological evidence - based claims in capital and non - capital cases, 20052012. e.g. for mental retardation, 1% of the claims raised in the study sample were for a claim of mental retardation in a non - capital case.) this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse the test for competency to stand trial is whether a criminal defendant has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding. at any point during a trial, the competency of a defendant can be challenged, but it often arises as a pretrial issue, to address whether the defendant has the present ability to proceed. finding a criminal defendant incompetent to stand trial rather, he may be indefinitely detained in a psychiatric facility until he is rendered competent, or if he never is, remain there until he no longer serves as a present danger to himself or to others. the data here show a frequent use of neurobiological evidence to challenge defendants competency during criminal proceedings. in 15 per cent of the neurobiological evidence - based claims raised in the study sample, the defendant argued that something unique about his brain rendered him incompetent to proceed during the criminal case. of the 15 per cent of all of the claims in the study pertaining to competency, 77 per cent of those challenged the competency of the defendant to stand trial. a smaller but increasing proportion of claims focused upon the defendant 's lack of competency to waive his rights, to plead guilty, or to have confessed to the crime or crimes at issue (see graph 7). this image / content is not covered by the terms of the creative commons licence of this publication. for permission to reuse consider for example the case of miguel angel ruiz, who was found incompetent to stand trial based on neuropsychological testimony about his brain disorders. in february 2007, 17-year - old miguel angel ruiz (ruiz) was charged with murdering his mother. in january of 2008, a trial court suspended criminal proceedings against ruiz to assess his competency to stand trial. after a hearing and a subsequent jury verdict finding ruiz competent to stand trial, the trial judge set aside the verdict and concluded that there was no reasonable, credible evidence to support a finding that ruiz was competent. ruiz presented testimony from two neuropsychologists who had performed a battery of tests on him. the prosecution introduced evidence from correctional officers who had interacted with ruiz while he was awaiting trial. one of the defense experts diagnosed ruiz with a severe language disorder that arose from an organic brain - processing deficit that interfered with his language skills. as a result, he had severe inability to converse, explain, or impart information, all critical elements of being able to assist in his own defense. another expert concluded similarly, that ruiz had a developmental language disorder, specifically that the left part of his brain, which deals with language skills, did not develop as well as the right part of the brain, which deals with nonverbal skills. the expert believed this was a congenital disorder because a brain injury after birth would have affected his motor skills, which were intact. after administering standard tests to determine if ruiz was faking his disorder, the expert testified that there was no evidence of malingering. i 'm not inclined to set aside a jury 's decision lightly or unadvisedly but quite frankly when i received the verdict after hearing the evidence, i was surprised. i just could n't believe the jury could return a finding of competency based on the evidence i heard the testimony of both experts in the court 's mind is very persuasive and as a result, i 'm setting aside the jury verdict in this matter. the california court of appeals for the fifth district affirmed the trial court 's decision to set aside the jury 's verdict on finding the defendant competent to stand trial. while highly unusual to set aside a jury 's finding of fact, neurobiological evidence appears to have powerful factual and persuasive appeal to judges. the result is that in a substantial portion of cases where competency is raised, credible evidence of neurobiological impairment may enable more legitimately impaired defendants to obtain a favorable finding of incompetent to proceed. similarly and relatedly, the right to due process under the united states constitution requires that a defendant 's guilty plea be knowing, voluntary, and intelligent. traditionally, the bar to withdrawing a guilty plea has been quite difficult to surmount. indeed, defendants are using neurobiological evidence to argue that based on their neurological functioning at the time of entering their guilty plea, they did not enter that plea in a knowing, voluntary and intelligent manner. in 2007, for example, richard hodges pleaded guilty to possession of cocaine and residential burglary. as the judge engaged in what is known as a plea colloquy, hodges occasionally appeared lost, asked questions about matters not relevant to the plea process, and exhibited confusion. they found no neurological reasons for richard 's problems and determined his learning abilities were within normal limits. after hearing all of the expert testimony, the judge concluded that hodges was not suffering from an organic brain disorder. in some cases, the court has set aside a guilty plea and remanded the case for an evidentiary hearing on claims of competency to enter a guilty plea. in other cases, the court has rejected the neurobiological evidence as contrary to his perceptions of competency based on the plea colloquy. to be sure, attempts to withdraw guilty pleas still largely fail. but it 's interesting to note the extent to which claims about the involuntariness or lack of competency to have entered a guilty plea are grounded in neurobiology. this is an area to watch over time to see if framing these issues as brain disorders will have an effect on case outcomes. in a much smaller portion of the defendants a particular difficulty for defendants raising these claims is the inability to go backward in time using present neuropsychiatric testing to understand the defendant 's competency when questioned months or years prior to being evaluated. daniel thomas, for example, was stopped for a traffic violation when the police officer noticed the smell of marijuana and a large blanket draped over what seemed to be a big square object in the back seat. later, he sought to suppress the evidence of his written confession, arguing that when he waived his right to remain silent he did not do so voluntarily, knowingly, or intelligently because he was suffering from severe migraine headaches and brain injury. a neuropsychologist testified at thomas 's suppression hearing that a brain injury could cause a degree of cognitive impairment that under stress would manifest more symptoms. these symptoms could include problems with attention, concentration, and memory. in combination with stress and sleep - depravation, thomas 's brain injury might impair his attention and concentration, and that poor attention in turn could impair his ability to process information. the judge acknowledged that the expert accurately described a person with traumatic brain injury but believed other evidence established that thomas had adequate memory and intelligence to voluntarily, knowingly, and intelligently waive of his miranda rights. the judge pointed to the time lapse before he wrote out his confession, and the counterexpert who said that given the defendant 's educational and professional background such a deficit could not be considered a significant impairment. based on the objective observations of the defendant 's capacities, the court was unconvinced that defendant 's brain injury impeded his ability to knowingly and intelligently waive his rights. this appears to be a rather typical outcome in these cases. because the present neurobiological evidence may have little bearing on the defendant 's actual competency to have confessed at the time of the crime, courts may give neurobiology little weight particularly in comparison to other circumstantial evidence that bears on the defendant 's likely capacities at the time. although it captures popular imagination, the insanity defense is raised infrequently and notoriously difficult to prove. although the precise requirement of the insanity defense varies by jurisdiction, an approach common to many states is the requirement that the defendant have a complete lack of understanding of the difference between right and wrong. this legal standard can be exceedingly difficult to establish, since mental illness typically results in some degree rather than complete impairment of understanding. jurors also tend to overcredit claims that a defendant is faking (malingering) their impairment. although the first issue, the legal standard of insanity, is nearly impossible to overcome, to whether the defendant is malingering is an area that neurobiological evidence may inform. it is for this second purpose bolstering claims of mental illness that defendants used neurobiological evidence in about four per cent of the claims analysed in the study. consider the case of mr chavez, who seemed to have a psychotic break while carrying a metal pole. perched at a busy intersection on the sidewalk and armed with a metal pipe, he menacingly approached cars as they stopped at a red light harassing them by asking is this your car ? the victims later testified that chavez looked kind of crazy and evil looking. when the police arrived, chavez told the officer to shoot him as he was going to smash him. he was ultimately arrested. at trial, his defense counsel argued that chavez was legally insane during the incident and introduced expert testimony that he was suffering from schizopaffective disorder of a bipolar type and a manic break at the time of the offense. a neuropsychologist testified that chavez had a dysfunction in the frontal lobe region of his brain with an iq of 79. a pet scan of defendant 's brain revealed certain abnormalities in the left lateral frontal area. the state 's expert countered that chavez 's mental illness had no impact on his ability to understand the nature and quality of his acts, and to know that his acts were wrong when he committed them, focusing on the legal concept of insanity. with regard to the incident involving the deputy, the state 's expert opined that the defendant intentionally attacked the deputy because he did n't like what he was being told, defendant 's awareness of what he was doing and that it was wrong. this example underscores that while neurobiological evidence may bolster a finding of mental illness or impairment, the legal standard for insanity may still remain an insurmountable hurdle for most defendants. and yet, neurobiological evidence can and has assisted some criminal defendants with their claims of legal insanity. a particularly telling case is highlighted in the 2011 opinion in the case of thomas curtis vs. the state of indiana. in december 2009, curtis was charged with murdering his wife. in 2010, curtis filed a notice of intent to introduce the insanity defense and the trial court appointed a psychologist and a psychiatrist to evaluate him. both experts testified that they believed curtis was insane at the time he killed his wife. both the psychologist and psychiatrist who evaluated curtis thought he was unable to appreciate the wrongfulness of his conduct. organic brain injury. upon review of the trial judge 's decision to enter a gbmi verdict the appellate court found that there was neither expert nor lay opinion that curtis was sane at the time he killed his wife. instead, the trial court had been swayed by the inadequacy of available treatment noting that in a state hospital curtis would be kicked out as soon they can, and then there 's no guarantees. the trial court rejected the insanity defense after concluding that the defendant could continue to be a danger to society because of an inadequate state mental health system. although sympathetic to the trial court 's concern, the appellate court credited the uncontroverted evidence of legal insanity, reversed the judgment of gbmi, and remanded the case for an entry of not guilty by reason of insanity and the appropriate commitment proceedings. the trial court 's concern is echoed throughout the study opinions. while neurobiological evidence may be compelling evidence to bolster a finding of incompetency or insanity, without adequate mental health treatment options available courts and juries are left to struggle with how to appropriately weigh the evidence while also safeguarding the community writ large from an admitted and potentially untreated or untreatable dangerous neurobiological predisposition. neurobiological evidence has been considerably less helpful in determining whether a defendant has committed a crime. neurobiological evidence is often used to challenge the folk psychological beliefs underlying criminal law : that actions are voluntary and the product of conscious choice. the alternative that actions arise from unconscious predispositions over which an individual has little control has made little inroads in criminal law. most basically, the concepts of voluntariness and intentionality in law do n't map well onto how those concepts are understood by scientists. nor does a theory that individuals are automatons and unable to control their actions align well with our subjective experiences of self - directed decision - making. finally, the science usually population - level science (such as a correlation between neurological or genetic variations and behavioral variations across a population)doesn't tell us much about why any particular individual behaved as they did. as a result, attempts to use neurobiological evidence for determinations of guilt or innocence seems to make far less of an impact than attempts in pretrial and sentencing determinations. in about 4 per cent of the study - sample claims (7 per cent of the judicial opinions) defendants argued that their neurobiology made them act involuntary. typically, this involved a claim of involuntary conduct following the voluntary ingestion of drugs or alcohol. prosecutors start out ahead as a matter of law in proving that a defendant acted voluntarily. this presumption means that the defense that a person acted involuntarily will only succeed in a narrow set of circumstances. involuntariness is recognized if a defendant 's actions were a reflex or convulsion, a bodily movement arising from unconsciousness, sleep, hypnosis, or by some factor other than actor 's will. these automatism cases are legal freaks, but a growing chorus of scientists argues that they should serve as a paradigm ; decision - making is primarily perhaps, unbeknownst to the chorus, those claims have been featured in criminal courtrooms. judges are certainly not allowing all of these claims into the courtroom as one opinion about a high - speed car chase makes plain. in this case, a police officer saw a known former criminal offender with an outstanding warrant for his arrest at a gas station, and approached him when the defendant returned to his car. the officer asked the defendant to step out of the car but the defendant instead instructed the driver to take off. what ensued was a high - speed car chase culminating in the driver stopping in the middle of the street and backing his car into the police officer 's car to injure him. the defendant was arrested and convicted with resisting arrest and assaulting the officer. on appeal he argued that the trial court judge made a legal error in excluding relevant expert testimony regarding his head injuries and subsequent blackouts. eight weeks prior to this incident a tree limb fell on his head. at the time he had a cat scan and mri performed on his head and neck. because of his head injury, the defendant claimed that he was acting unconsciously in a blacked out state of shock during the police chase. the trial judge excluded the neurobiological evidence because it was misleading and irrelevant. a mere failure to remember an event does not excuse its occurrence unless the failure to remember signifies involuntary or unconscious conduct. instead, the experts agreed that while the defendant had been hit on the head the mri and other evidence did not support neurological trauma, blackouts, or states of unconsciousness. nearly 40 per cent of the opinions addressing automatism claims do not discuss any neurological testing of the criminal defendant. instead, the claims appear to be rooted in past head injuries or other trauma the defendant alleges to have suffered. it 's all the more important that neuroscientists start talking about the responsible use of neurobiological evidence in law, because it has already influenced jury decision - making about defendants mental states. in approximately 10 per cent of all the claims raised in the study, the defendant argued that neurobiological evidence showed he lacked the mental state necessary to commit the crime. the typical defendant uses neurobiological information to argue that he acted impulsively rather than with the premeditation or purpose contemplated by the crime definition. so claimed john gunther who was charged with first - degree murder of his mother in 2008. gunther used a metal pipe to bludgeon his mother to death and she died of blunt force trauma to her head. he did so apparently to steal her money, television, vcr, and jewelry to purchase drugs. he admitted to killing his mother and threatening to do so many time but denied planning or intending to kill her. in support of his claim, two experts testified on his behalf. the first, a clinical psychologist and neuropsychologist, reviewed gunther 's medical records and evidence of head trauma in 2007 and again in 2008. this medical history together with a series of neuropsychological tests the expert administered supported his conclusion that gunther had damage to his frontal lobe possibly reducing his ability to premeditate or deliberate, and instead causing him to act impulsively on the night he killed his mother. a second expert concurred echoing that gunther 's brain injuries could explain killing his mother as impulsive and affect[ing ] his ability to form mental states such as specific intent to kill his mother, premeditation or deliberation. the jury nevertheless found gunther guilty of first - degree murder, which requires deliberation and premeditation. in reviewing the jury 's determination on appeal the court found the jury reached a reasonable conclusion : here, the jury reasonably could conclude that gunther planned to murder his mother. he repeatedly told several people, over an extended period of time, that he hated her. gunther 's conversations were sufficiently frequent and detailed as to signal his intent to murder his mother, which he eventually did. this opinion is consistent with how other courts approach neurobiological evidence when used to challenge mental state. presented with circumstantial evidence consistent with planning and premeditation and with conflicting neurobiological evidence, judges and juries tend to credit the circumstantial evidence over the neurobiological. this may be in part because of the near impossibility of understanding the defendant 's mental state at the time the crime was committed. neurobiological evaluations can not take us backward in time to understand what the defendant was thinking, feeling, or why the defendant acted as he did. but the missing link between predisposition evidence and the causes and intentions of any specific actions can not presently be overcome. moreover, concepts like mental states are narrower in criminal law than the lay perspective may assume. mental state in criminal law is about the intentionality with respect to the specific act in question. did the defendant mean to swing the pipe (purpose of the act), understanding the person he was swinging the pipe at was another human being (the circumstances), and that the impact of swinging a pipe at another person would be to cause grave bodily suffering or injury (consequences) ? with this narrow understanding of the mental state necessary to convict a criminal defendant, it becomes apparent that at least as the law is presently understood neurobiological evidence may provide little support. in only the rare case will neurobiological evidence address the purpose of the act, an understanding of the circumstances or anticipation of the consequences. more direct dialog between neuroscientists and attorneys could better inform both groups about how concepts like voluntariness and mental state differ in both law and science, which could lead to more responsible testimony by neuroscientists in criminal cases about the (ir) relevance of neurobiological evidence to determining the voluntariness or mental state of the defendant. greater engagement by leading neuroscientists in the legal process would substantially improve both judges and jurors understanding of the limitations of science in answering the questions that law poses in addressing voluntariness and mental state. fundamentally, neurobiological evidence is fueling a societal debate about why we punish people who commit crimes. if so, would this goal be better served by rehabilitating and reintegrating into society those who commit crimes ? although neurobiological evidence can not answer these philosophical questions for us, it can provide empirical evidence about human behavior that bear on these discussions. and yet, neurobiological data may tell us little about any particular defendant and whether they are deserving of punishment. it 's this concern that studies do not tell us why a particular person behaved as they did that seems to motivate many scientists to oppose the use of neurobiological evidence in sentencing. but regardless of whether scientists agree or not about the appropriate role of neurobiological evidence in criminal law, neurobiological evidence seems clearly entrenched in sentencing decisions. developmental neuroscience has served as the empirical basis for recent constitutional prohibitions against the execution of or life imprisonment of juveniles. and there may be a coming tsunami of neurobiological evidence - backed sentencing claims at trial. trial attorneys have already been found ineffective at trial because they failed to investigate a defendant 's probable neurological abnormality (even though defendants rarely prevail otherwise on such claims). nearly half of those claims were the defendant arguing he received ineffective assistance of counsel by failing to introduce neurobiological evidence at sentencing. more than half of the sentencing claims were for capital cases, while the remaining 42 per cent were non - capital cases. to establish a defendant received ineffective assistance of counsel he must show that his attorney acted below an objective standard of reasonableness, and there was a reasonable probability that but for counsel 's unprofessional errors the outcome of the case likely would have been different. in fact, even when defense counsel has slept through substantial portions of a trial, judges have ruled that defendants did not receive ineffective assistance of counsel. it 's particularly notable then that judges have already found that failing to investigate a reasonable probability of a brain abnormality constitutes ineffective assistance of counsel. even in cases with horrific facts, judges have found neurobiological evidence an essential component of counsel investigation. in one case, a defendant and his coworker went to a bar in arizona where they consumed almost two - dozen beers. when they left the bar, they picked up a female victim walking along the side of the road. eventually, things turned badly between these three and one of the defendants turned a knife on the woman. he sexually assaulted her, slit her throat, stabbed her over 30 times and then left her mutilated body in the desert. he was convicted by a jury of first - degree murder and sentenced to death. he presented volumes of new evidence on appeal about his brain damage and neuropsychological deficits. the court found a reasonable probability that the sentencing judge would have imposed a sentence less than death had the defendant 's counsel obtained and presented an expert evaluation of his neuropsychological functioning. powerful evidence of mitigation and therefore found that the defendant 's trial counsel had rendered ineffective assistance of counsel by failing to investigate it. defense counsel are ineffective if they fail to mount a defense at all, sleep through an entire (but not just parts of) a trial, or if they fail to investigate a probable neurological abnormality in a defendant. one of these things is not like the others, and its oddity makes clear that neurobiological evidence is an embedded part of the criminal process. to further underscore this point, consider that it may be entirely reasonable to choose not to introduce neurological evidence because of it 's double - edged potential. when the defendant connie was convicted of burglary, battery, kidnapping, sexual battery with great force, and first - degree murder of 77-year - old woman in her own home, his neurobiological evidence - based defense did n't just fail, it did so miserably. in the closing statement of the trial, the prosecutor summed up the neurobiological evidence he introduced saying : so, what are we left with ? a doctor [] comes in and tells you he could n't help it, he was born that way. this man was born evil, born bad, he 's going to be that way for now on and there 's nothing i can do except identify it for you. he 's got diffuse brain damage and he goes around raping women and beating them up... how much weight do you give to he just does it because he does it ? the jury voted 11 - 1 in favor of the death penalty, and the judge followed their recommendation. it 's entirely unsurprising that even upon discovering neurobiological evidence defense attorneys may often choose to forego using it as part of mitigation. once a criminal defendant has been released from prison he can be involuntarily civilly committed if he continues to serve as a danger to himself or the community. this is most prevalent in cases of sexually violent predators, which requires proving that a person has a past conviction of a sexual offense, is likely to reoffend, and has a diagnosed mental disorder that makes the person a danger to the health and safety of others. some of the brain abnormality evidence introduced by a criminal defendant at trial can cut against him at a civil commitment hearing. for example, when a defendant committed a series of sexually violent attacks and was convicted and sentenced to 15 years in state prison, he was sent to a state hospital as a mentally disordered sex offender instead. while there, he failed the treatment programs because of his repeated sexual advances to female staff members. in a later civil commitment proceeding, the court weighed heavily that the defendant had suffered a serious head injury when struck in the head by the butt of a shotgun. a year and a half after the injury, his behavior became more aggressive, and the experts concluded that the brain injury was likely a factor in his crimes. based on this evidence, the court concluded that the defendant 's capacity to control his violent sexual tendencies would be seriously impaired if released into the community and committed him to confined institutionalization. ninety - one of the cases in the study pertained to juveniles (about 6 per cent). the developing brain theory is about the juvenile brain generally, rather than specifically about the particular offender. these defendants argue that the juvenile brain is still developing that the frontal lobe region is still underdeveloped and that the brain is not fully myelinated and that as a result juveniles should be treated less harshly than adults. the fact that the brain is still developing means a juvenile has less capacity for self - restraint, but also means that their criminal conduct is not representative of how they will behave as an adult with a fully developed brain. in a triology of cases, the united states supreme court has cited to evidence about the developing juvenile brain to find it unconstitutional under the eighth amendment of the united states constitution to executive juveniles, to impose life without the possibility of parole for non - homicidal offenders, or to have a mandatory scheme of life imprisonment without the possibility of parole. since the latest of these cases, miller v. alabama, there is considerable confusion and debate by lower courts about the meaning of that ruling and the extent to which a judge must consider neuroscience when sentencing a juvenile offender. generally, between 20 and 30 per cent of defendants enjoy some success on appeal, in part because of neurobiological evidence, in capital case and non - capital case alike. although a one - to - one comparison of matched cases where neurobiological evidence was not introduced can not be done to accurately understand how neuroscience impacts case outcomes, the success rate on appeal in these cases appears to be higher than in criminal appeals in general. comparing the reversal rates in these cases versus all criminal appellate cases, the reversal rate in cases with neurobiological evidence is higher. in a 2010 study of the estimate 69,348 criminal appeals in the us, in only about 12 per cent of the cases did the appellate court reverse, remand, or modify a component of the trial courts decision. whereas the success rate in death penalty study cases was 23 per cent (merits and non - merits cases together), compared to the 18.6 per cent success rate in death - penalty merits appeals overall. the success rate in non - capital cases also appears to be higher in the study cases the general reversal rate in non - capital cases was 7.7 per cent (merits cases) and 2.3 per cent (without a review of the merits), while the overall reversal rate was 20 per cent in the non - capital cases in the study. + means the defendant achieved a positive outcome on appeal, whether as a reversal, remand, or modification of a component of the trial courts decision. we have not been able to locate any comparable data against which the relative success rate in juvenile cases with and without neurobiological cases can be compared. the study cases show that, in general, the juvenile defendants fared better than adult defendants, in some categories achieving as high as a 38 per cent favorable outcome on appeal (see graph 9). favorable means the defendant achieved a positive outcome on appeal, whether as a reversal, remand, or modification of a component of the trial courts decision. the use of neurobiological evidence in criminal cases may draw serious criticism and justifiable concern by scientists. but neurobiological evidence also has improved the criminal justice system through better competency determinations and reconsiderations about the role of punishment in society. and neurobiological evidence at times replaces what was even shoddier evidence that we relied about to make inferences about the individual capacities and behavior of a criminal defendant. given the recent rulings about the neurobiological evidence and ineffective assistance of counsel, it 's safe to assume that neurobiological evidence is now a mainstay of our criminal justice system. as a result, it 's time for a more nuanced dialog between neuroscientists, legal decision - makers, and the public about the role of neurobiological evidence in the criminal courtroom. it 's no longer productive to call for outright bans ; neuroscientists should help to improve public understanding about what neurobiological evidence can and can not tell us about human behavior. at the same time, the dialog about how neurobiological evidence is being used in criminal cases by legal scholars, commentators, and the media should account for the differences between popular perception and the results of this study. some successful efforts are already underway to improve public understanding of law and cognitive neuroscience. to name a few, the dana foundation and the american association for the advancement of science have launched a neuroscience in society series that has hosted a number of pertinent events to inform judges and the public about advances in cognitive neuroscience. the john d. and catherine t. macarthur foundation funded a multiyear project on law and neuroscience, which includes an educational component. the royal society in london has issued a four - part series of accessible reports on the developments in neuroscience and their implications for society, public policy, and law. the presidential commission for the study of bioethical issues has issued a two - part report entitled grey matters, that includes a detailed chapter and recommendations on law and neuroscience. dozens of worldwide academic conferences have been held on the topic. and a recent pbs special entitled brains on trial engaged neuroscientists, philosophers, and lawyers to educate the public about these developing trends. but more can and should be done to engage the public on these issues neuroscientists should be at the forefront of this conversation as experts in criminal courtrooms, in public presentations, through accessible writing for public audiences, or by filing amicus briefs in legal cases where neurobiological evidence is at issue. neurobiological evidence has profound implications for some of the most significant decisions we make in law and policy. it 's time we better understand how it 's being used and start to address how it may be better used in our criminal justice system. | the goal of this study was to examine the growing use of neurological and behavioral genetic evidence by criminal defendants in us criminal law. judicial opinions issued between 200512 that discussed the use of neuroscience or behavioral genetics by criminal defendants were identified, coded and analysed. criminal defendants are increasingly introducing such evidence to challenge defendants competency, the effectiveness of defense counsel at trial, and to mitigate punishment. |
according to european society of cardiology guidelines, hypertension is usually defined as resistant or refractory to treatment when a therapeutic plan that has included attention to lifestyle measures and the prescription of at least three drugs (including a diuretic) in adequate doses has failed to lower systolic (spb) and diastolic blood pressure (dbp) to goal (1,5 mg / dl or 133 mol / l and/or proteinuria > 300 mg/24h) as failure to achieve bp level up to 135/75 mmhg with the above mentioned criteria (2). some authors include inability to lower sbp below 160 mmhg in patients with isolated systolic hypertension. the latter includes all hypertensive patients lacking bp control under therapy, those who underwent inadequate therapeutic regimen, those with poor compliance, and those with undiscovered secondary hypertension, as well as those who are really resistant to treatment. although the definition for resistant hypertension is arbitrary in regard to the number of needed antihypertensive drugs, the concept of resistant hypertension is directed towards recognizing the patients that are under high risk of having reversible causes for hypertension, and/or patients who will, because of permanently high level bp, use special diagnostic and therapeutic considerations (3). pseudoresistance is defined as lack of control over bp levels caused by inappropriate bp measurement, inappropriate drug choice / dosage, lack of compliance to prescribed therapy, or by white - coat effect. white - coat hypertension is to be considered in patients who have repeatedly high bp ambulatory measured without proof of target organs damage. white - coat hypertension has better prognosis than resistant hypertension, but has a higher cardiovascular risk than in persons with normal bp levels (2). the prevalence of resistant hypertension is unknown : epidemiological researches on resistant hypertension are missing. the data of frequency can be taken out from observational and big controlled clinical studies in which many participants partaken. for example, in allhat study after five year follow - up, 34% of participants had uncontrolled arterial hypertension, and 27% had resistant hypertension (5). at the end of the study, 8% of participants were prescribed four or more drugs, while 15% of participants were classified in resistant hypertension group (5). in value study 15% of patients received three or more drugs, and 61% of them retained high bp (6). based on specified data from mentioned studies, the prevalence in united states of america (usa) and europe is between 10 to 30% among patients with hypertension. according to persell s results, 12.8% of antihypertensive drug - treated adults if we compare the resistant hypertension frequency in gp s office where prevalence is around 5% with nephrologists office where the prevalence (because of patients selection) is up to 50%, we can see how hard it is to estimate the exact number of patients with resistant hypertension (8). in opposition to usa and europe data, for the time being it is not possible to assess the prevalence of resistant hypertension in croatia due to lack of research on the subject. according to sarafidis and bakris (3) many biological and life - style factors can contribute to the development of resistant hypertension : drugs induced : nonsteroidal anti - inflammatory drugs (including cyclo - oxygenase-2 inhibitors), sympathomimetics (decongestants, anorectics), cocaine, amphetamines, other illicit drugs, oral contraceptive hormones, adrenal steroid hormones, erythropoietin, cyclosporine and tacrolimus, licorice (included in some chewing tobacco), over - the - counter dietary and herbal supplements (e.g., ginseng, yohimbine, ma huang, bitter orange) volume overload : excess sodium intake, volume retention from kidney disease, inadequate diuretic therapy associated conditions : obesity, diabetes mellitus, older age identifiable causes of hypertension : renal parenchymal disease, renovascular disease, primary aldosteronism, obstructive sleep apnea, pheochromocytoma, cushing s syndrome, thyroid diseases, aortic coarctation, intracranial tumors renal physiology contributes to circadial variability of blood pressure levels. the time - related profile of blood pressure levels shows a morning increase, a deeper descent during nocturnal rest : 10 - 20% drop during the night in healthy subject. patients with secondary hypertension very often display abnormal circadian blood pressure profile, leading to the non - dipper pattern, requiring different ingestion - time dependent strategies for therapy of hypertension medications (9). according to article published by calhoun. 2008 in circulation, the evaluation of patients with resistant hypertension should, be directed toward confirming true treatment resistance ; identification of causes contributing to treatment resistance, including secondary causes of hypertension ; and documentation of target - organ damage (10). accurate assessment of treatment adherence and use of good bp measurement technique is required to exclude pseudoresistance. target - organ damage such as retinopathy, chronic kidney disease, and left ventricle hypertrophy supports a diagnosis of poorly controlled. suggest following algorithms for establishing resistant hypertension diagnosis (10) : the medical history should document duration, severity, and progression of the hypertension ; treatment adherence ; response to prior medications, including adverse events ; current medication use, including herbal and over - the - counter medications ; and symptoms of possible secondary causes of hypertension. daytime sleepiness, loud snoring, and witnessed apnea are suspicious for sleep apnea. a history of peripheral or coronary atherosclerotic disease increases the likelihood of renal artery stenosis. labile hypertension, in association with palpitations and/or diaphoresis, suggests the possibility of pheochromocytoma. assessing compliance. ultimately, adherence in a clinical setting can only be known by patient self - report. patients should be specifically asked how successful they are in taking all of their prescribed doses, including discussion of adverse effects, out - of - pocket costs, and dosing inconvenience, all of which can limit adherence. family members will often provide more objective assessments of a patient s adherence, but such input should generally be solicited in the presence of the patient. direct observation of therapy is the most accurate method but is burdensome to both patients and providers and impractical for chronic diseases. blood or urine measurements of drug levels or biologic markers are expensive and may falsely suggest adherence in patients who take their medications only around the time of their clinic visit white coat adherence. they also state that gold standard in assessing adherence and can provide daily information on patient pillbox access with timing intervals. the medication event monitoring system (mems) records each time and date that the pillbox is opened and electronically stores this information, which can later be accessed by computer. these devices are the most reliable system for monitoring adherence and have been shown to improve adherence in hypertensive patients : 30% of patients with a prior diagnosis of resistant hypertension normalized their blood pressure by undergoing electronic adherence monitoring, and an additional 20% were identified as non - adhering to the medication regimen. use of adequate bp measurement technique is essential to the accurate diagnosis of resistant hypertension, including having the patient sit quietly in a chair with his or her back supported for 5 minutes before taking the measurement ; use of the correct cuff size with the air bladder encircling at least 80% of the arm (the adult large cuff for the majority of patients) ; and supporting the arm at heart level during the cuff measurement. a minimum of 2 readings should be taken at intervals of at least 1 minute and the average of those readings should be taken to represent the patient s bp. the bp should be measured carefully on both arms and the arm with the higher pressures generally should be used to make future measurements (10). a fundoscopic examination the presence of carotid, abdominal, or femoral bruits increases the possibility that renal artery stenosis exists. diminished femoral pulses and/or a discrepancy between arm and thigh bps suggest aortic coarctation or significant aortoiliac disease. cushing s disease is suggested by abdominal striae, particularly if pigmented ; moon facies ; or prominent interscapular fat deposition (10). documentation of a significant white - coat effect requires reliable assessment of out - of - office blood pressure values. this is accomplished most objectively with the use of 24-hour ambulatory blood pressure monitoring (abpm) (10). abpm has greater diagnostic value and is useful in assessing patients for white coat hypertension, episodic hypertension, autonomic dysfunction, and masked hypertension and will determine whether patients have the appropriate nocturnal dip in blood pressure of 10%20%. patients without the appropriate nocturnal dip have increased cardiovascular risk, so the evaluation of resistant hypertension including 24h ambulatory monitoring of blood pressure in the identification of non - dipper hypertension (2,9). non - dipper has particular importance and the prevalence of abnormally high asleep blood pressure is very often in chronic kidney disease patients. therapeutic restoration of normal physiologic blood pressure reduction during night - time sleep is the most significant independent predictor of decreased cardiovascular risk in patients with chronic kidney disease (ckd)(9). biochemical evaluation of the treatment - resistant hypertensive should include a routine metabolic profile (sodium, potassium, chloride, bicarbonate, glucose, blood urea nitrogen, and creatinine) ; urinalysis ; and a paired, morning plasma aldosterone and plasma renin or plasma renin activity to screen for primary aldosteronism. even in the setting of ongoing antihypertensive treatment (excluding potassium sparing diuretics, particularly aldosterone antagonists), the aldosterone / renin ratio is an effective screening test for primary aldosteronism, having a high negative predictive value. a high ratio has a low specificity for primary aldosteronism, likely reflecting the common occurrence of low - renin hypertension in patients with resistant hypertension. a 24-hour urine collected during ingestion of the patient s normal diet can be helpful in estimating dietary sodium and potassium intake, calculating creatinine clearance, and measuring aldosterone excretion. measurement of 24-hour urinary metanephrines or plasma metanephrines is an effective screen for patients in whom pheochomocytoma is suspected (10). in opposite to calhoun statements, according to park and capese, an aldosterone - to - plasma renin activity ratio of greater than 20:1 is usually considered suggestive of primary aldosteronism, with sensitivity and specificity of 89% and 71%, respectively (2). imaging for renal artery stenosis should be reserved for patients in whom there is an increased level of suspicion. this would include young patients, particularly women, whose presentation suggests the presence of fibromuscular dysplasia and older patients at increased risk of atherosclerotic disease. the preferred imaging modality will vary by institution, depending on the level of training and experience. for patients with ckd, modalities that do not involve iodinated contrast may be preferred over computed tomography (ct) angiography. likewise, due to poor specificity, abdominal ct imaging is not recommended to screen for adrenal adenomas in the absence of biochemical confirmation of hormonally active tumors (hyperaldosteronism, pheochromocytoma, cushing s syndrome) (8). oppose to calhoun., park and campese state that in patients with a high ratio and hypokalemia, further workup can be performed with a sodium loading test ; patients with an abnormal response can then undergo adrenal imaging with computed tomography or magnetic resonance imaging. left ventricular hypertrophy determined by cornell voltage on ecg is associated with resistant hypertension, and ecg strain pattern (s in v3 + r in avl > 28 mm for men ; and s in v3 + r in avl > 20 mm for women) is independently associated with increased left ventricular wall thickness and other adverse factors in patients with resistant hypertension. additionally, all patients with resistant hypertension should have a glomerular filtration rate calculated by the modification of diet in renal disease (mdrd) or chronic kidney disease epidemiology collaboration (ckd - epi) equation to better discern the level of kidney function (12). renovascular disease is highly prevalent in the elderly population, but it may be difficult to determine whether the disease is indeed the cause of the resistant hypertension. screening for renovascular disease may be performed with doppler ultrasonography, magnetic resonance angiography, or angiotensin - converting enzyme inhibitor renography. treatment of resistant hypertension is predicated on identification and reversal of lifestyle factors contributing to treatment resistance ; accurate diagnosis and appropriate treatment of secondary causes of hypertension ; and use of effective multi - drug regimens. potential measures that could contribute to welfare of the patients with resistant hypertension are : non - pharmacological : lifestyle changes (weight loss, regular exercise, ingestion of a high - fiber, low - fat, low - salt diet ; and moderation of alcohol intake)pharmacological : compared with morning administration, dosing one or more antihypertensive medications at bedtime helps induce a normal circadian bp pattern and reduces the cardiovascular risk. in chronic kidney disease (ckd), the diagnosis of hypertension and treatment are based usually on daytime clinic blood pressure measurements. evidence is that the asleep bp better predicts cardiovascular events than the awake or 24 h blood pressure mean. a small retrospective analysis assessing the safety of spironolactone (on angiotensin - converting enzyme inhibitors or angiotensin ii receptor blockers, calcium - channel blockers, beta blockers and diuretics) in patients with resistant hypertension suggests that hyperkalemia occurs not infrequently and that further studies are needed to assess the safety of the drug in these difficult - to - treat patients (13).treatment of secondary causes of hypertension (obstructive sleep apnea, renal artery stenosis) invasive procedures : carotid sinus stimulation, renal denervation (10). non - pharmacological : lifestyle changes (weight loss, regular exercise, ingestion of a high - fiber, low - fat, low - salt diet ; and moderation of alcohol intake) pharmacological : compared with morning administration, dosing one or more antihypertensive medications at bedtime helps induce a normal circadian bp pattern and reduces the cardiovascular risk. in chronic kidney disease (ckd), the diagnosis of hypertension and treatment are based usually on daytime clinic blood pressure measurements. evidence is that the asleep bp better predicts cardiovascular events than the awake or 24 h blood pressure mean. a small retrospective analysis assessing the safety of spironolactone (on angiotensin - converting enzyme inhibitors or angiotensin ii receptor blockers, calcium - channel blockers, beta blockers and diuretics) in patients with resistant hypertension suggests that hyperkalemia occurs not infrequently and that further studies are needed to assess the safety of the drug in these difficult - to - treat patients (13). treatment of secondary causes of hypertension (obstructive sleep apnea, renal artery stenosis) invasive procedures : carotid sinus stimulation, renal denervation (10). volume overload : excess sodium intake, volume retention from kidney disease, inadequate diuretic therapy associated conditions : obesity, diabetes mellitus, older age identifiable causes of hypertension : renal parenchymal disease, renovascular disease, primary aldosteronism, obstructive sleep apnea, pheochromocytoma, cushing s syndrome, thyroid diseases, aortic coarctation, intracranial tumors renal physiology contributes to circadial variability of blood pressure levels. the time - related profile of blood pressure levels shows a morning increase, a deeper descent during nocturnal rest : 10 - 20% drop during the night in healthy subject. patients with secondary hypertension very often display abnormal circadian blood pressure profile, leading to the non - dipper pattern, requiring different ingestion - time dependent strategies for therapy of hypertension medications (9). according to article published by calhoun. 2008 in circulation, the evaluation of patients with resistant hypertension should, be directed toward confirming true treatment resistance ; identification of causes contributing to treatment resistance, including secondary causes of hypertension ; and documentation of target - organ damage (10). accurate assessment of treatment adherence and use of good bp measurement technique is required to exclude pseudoresistance. target - organ damage such as retinopathy, chronic kidney disease, and left ventricle hypertrophy supports a diagnosis of poorly controlled. suggest following algorithms for establishing resistant hypertension diagnosis (10) : the medical history should document duration, severity, and progression of the hypertension ; treatment adherence ; response to prior medications, including adverse events ; current medication use, including herbal and over - the - counter medications ; and symptoms of possible secondary causes of hypertension. a history of peripheral or coronary atherosclerotic disease increases the likelihood of renal artery stenosis. labile hypertension, in association with palpitations and/or diaphoresis, suggests the possibility of pheochromocytoma. assessing compliance. ultimately, adherence in a clinical setting can only be known by patient self - report. patients should be specifically asked how successful they are in taking all of their prescribed doses, including discussion of adverse effects, out - of - pocket costs, and dosing inconvenience, all of which can limit adherence. family members will often provide more objective assessments of a patient s adherence, but such input should generally be solicited in the presence of the patient. direct observation of therapy is the most accurate method but is burdensome to both patients and providers and impractical for chronic diseases. blood or urine measurements of drug levels or biologic markers are expensive and may falsely suggest adherence in patients who take their medications only around the time of their clinic visit white coat adherence. they also state that gold standard in assessing adherence and can provide daily information on patient pillbox access with timing intervals. the medication event monitoring system (mems) records each time and date that the pillbox is opened and electronically stores this information, which can later be accessed by computer. these devices are the most reliable system for monitoring adherence and have been shown to improve adherence in hypertensive patients : 30% of patients with a prior diagnosis of resistant hypertension normalized their blood pressure by undergoing electronic adherence monitoring, and an additional 20% were identified as non - adhering to the medication regimen. use of adequate bp measurement technique is essential to the accurate diagnosis of resistant hypertension, including having the patient sit quietly in a chair with his or her back supported for 5 minutes before taking the measurement ; use of the correct cuff size with the air bladder encircling at least 80% of the arm (the adult large cuff for the majority of patients) ; and supporting the arm at heart level during the cuff measurement. a minimum of 2 readings should be taken at intervals of at least 1 minute and the average of those readings should be taken to represent the patient s bp. the bp should be measured carefully on both arms and the arm with the higher pressures generally should be used to make future measurements (10). the presence of carotid, abdominal, or femoral bruits increases the possibility that renal artery stenosis exists. diminished femoral pulses and/or a discrepancy between arm and thigh bps suggest aortic coarctation or significant aortoiliac disease. cushing s disease is suggested by abdominal striae, particularly if pigmented ; moon facies ; or prominent interscapular fat deposition (10). documentation of a significant white - coat effect requires reliable assessment of out - of - office blood pressure values. this is accomplished most objectively with the use of 24-hour ambulatory blood pressure monitoring (abpm) (10). abpm has greater diagnostic value and is useful in assessing patients for white coat hypertension, episodic hypertension, autonomic dysfunction, and masked hypertension and will determine whether patients have the appropriate nocturnal dip in blood pressure of 10%20%. patients without the appropriate nocturnal dip have increased cardiovascular risk, so the evaluation of resistant hypertension including 24h ambulatory monitoring of blood pressure in the identification of non - dipper hypertension (2,9). non - dipper has particular importance and the prevalence of abnormally high asleep blood pressure is very often in chronic kidney disease patients. therapeutic restoration of normal physiologic blood pressure reduction during night - time sleep is the most significant independent predictor of decreased cardiovascular risk in patients with chronic kidney disease (ckd)(9). biochemical evaluation of the treatment - resistant hypertensive should include a routine metabolic profile (sodium, potassium, chloride, bicarbonate, glucose, blood urea nitrogen, and creatinine) ; urinalysis ; and a paired, morning plasma aldosterone and plasma renin or plasma renin activity to screen for primary aldosteronism. even in the setting of ongoing antihypertensive treatment (excluding potassium sparing diuretics, particularly aldosterone antagonists), the aldosterone / renin ratio is an effective screening test for primary aldosteronism, having a high negative predictive value. a high ratio has a low specificity for primary aldosteronism, likely reflecting the common occurrence of low - renin hypertension in patients with resistant hypertension. a 24-hour urine collected during ingestion of the patient s normal diet can be helpful in estimating dietary sodium and potassium intake, calculating creatinine clearance, and measuring aldosterone excretion. measurement of 24-hour urinary metanephrines or plasma metanephrines is an effective screen for patients in whom pheochomocytoma is suspected (10). in opposite to calhoun statements, according to park and capese, an aldosterone - to - plasma renin activity ratio of greater than 20:1 is usually considered suggestive of primary aldosteronism, with sensitivity and specificity of 89% and 71%, respectively (2). imaging for renal artery stenosis should be reserved for patients in whom there is an increased level of suspicion. this would include young patients, particularly women, whose presentation suggests the presence of fibromuscular dysplasia and older patients at increased risk of atherosclerotic disease. the preferred imaging modality will vary by institution, depending on the level of training and experience. for patients with ckd, modalities that do not involve iodinated contrast may be preferred over computed tomography (ct) angiography. likewise, due to poor specificity, abdominal ct imaging is not recommended to screen for adrenal adenomas in the absence of biochemical confirmation of hormonally active tumors (hyperaldosteronism, pheochromocytoma, cushing s syndrome) (8). oppose to calhoun., park and campese state that in patients with a high ratio and hypokalemia, further workup can be performed with a sodium loading test ; patients with an abnormal response left ventricular hypertrophy determined by cornell voltage on ecg is associated with resistant hypertension, and ecg strain pattern (s in v3 + r in avl > 28 mm for men ; and s in v3 + r in avl > 20 mm for women) is independently associated with increased left ventricular wall thickness and other adverse factors in patients with resistant hypertension. additionally, all patients with resistant hypertension should have a glomerular filtration rate calculated by the modification of diet in renal disease (mdrd) or chronic kidney disease epidemiology collaboration (ckd - epi) equation to better discern the level of kidney function (12). renovascular disease is highly prevalent in the elderly population, but it may be difficult to determine whether the disease is indeed the cause of the resistant hypertension. screening for renovascular disease may be performed with doppler ultrasonography, magnetic resonance angiography, or angiotensin - converting enzyme inhibitor renography. treatment of resistant hypertension is predicated on identification and reversal of lifestyle factors contributing to treatment resistance ; accurate diagnosis and appropriate treatment of secondary causes of hypertension ; and use of effective multi - drug regimens. potential measures that could contribute to welfare of the patients with resistant hypertension are : non - pharmacological : lifestyle changes (weight loss, regular exercise, ingestion of a high - fiber, low - fat, low - salt diet ; and moderation of alcohol intake)pharmacological : compared with morning administration, dosing one or more antihypertensive medications at bedtime helps induce a normal circadian bp pattern and reduces the cardiovascular risk. in chronic kidney disease (ckd), the diagnosis of hypertension and treatment are based usually on daytime clinic blood pressure measurements. evidence is that the asleep bp better predicts cardiovascular events than the awake or 24 h blood pressure mean. a small retrospective analysis assessing the safety of spironolactone (on angiotensin - converting enzyme inhibitors or angiotensin ii receptor blockers, calcium - channel blockers, beta blockers and diuretics) in patients with resistant hypertension suggests that hyperkalemia occurs not infrequently and that further studies are needed to assess the safety of the drug in these difficult - to - treat patients (13).treatment of secondary causes of hypertension (obstructive sleep apnea, renal artery stenosis) invasive procedures : carotid sinus stimulation, renal denervation (10). non - pharmacological : lifestyle changes (weight loss, regular exercise, ingestion of a high - fiber, low - fat, low - salt diet ; and moderation of alcohol intake) pharmacological : compared with morning administration, dosing one or more antihypertensive medications at bedtime helps induce a normal circadian bp pattern and reduces the cardiovascular risk. in chronic kidney disease (ckd), the diagnosis of hypertension and treatment are based usually on daytime clinic blood pressure measurements. evidence is that the asleep bp better predicts cardiovascular events than the awake or 24 h blood pressure mean. a small retrospective analysis assessing the safety of spironolactone (on angiotensin - converting enzyme inhibitors or angiotensin ii receptor blockers, calcium - channel blockers, beta blockers and diuretics) in patients with resistant hypertension suggests that hyperkalemia occurs not infrequently and that further studies are needed to assess the safety of the drug in these difficult - to - treat patients (13). treatment of secondary causes of hypertension (obstructive sleep apnea, renal artery stenosis) invasive procedures : carotid sinus stimulation, renal denervation (10). the achievement of blood pressure values below 140/90 mmhg is considered one of the main methods of achieving high long term patient quality of life. nevertheless, a substantial number of patients do not achieve target blood pressure values in spite of taking at least three antihypertensive medications in adequate dosage of which one is a diuretic, so resistant hypertension is still unrecognized as a diagnosis and insufficiently researched. because of diagnostic procedure complexity, both doctor and patient motivation can be absent. although the most common causes of therapeutic failure are undiscovered secondary causes of hypertension and lack of patient compliance, in about 10% of cases it can be attributed to resistant hypertension caused by a hyperactivity of the sympathetic nervous system. increased activation of the sympathetic nervous system is identified as an important factor in the development and progression of hypertension. in this context has been developed catheter - based approach to disrupt the renal sympathetic nerves - renal denervation. even though this method is promising, criticism is directed at inadequately designed mostly observational studies without 24h ambulatory blood pressure measurement records, coupled with a significant variability in patient response to therapy (14). that is why it is important to finally assess the effectiveness of renal denervation and the influence it might have on reducing cardiovascular morbidity and mortality. among patients with resistant hypertension it is very important to select patients most likely to have benefit from renal denervation, because they represent a very mixed group of diagnoses. resistant hypertension in chronic kidney disease contributes significantly to increased cardiovascular risk and progression of kidney damage. in patients with the salt - sensitive type of hypertension or chronic kidney disease the nigh time drop of blood pressure although chronotherapy is not uniformly recommended in the treatment of resistant hypertension, it is a cost - effective strategy for reducing cardiovascular risk. further investigation is needed to evaluate the importance of chronotherapy on cardiovascular outcomes in resistant hypertension chronic kidney disease patients. | resistant hypertension is defined as blood pressure that remains above 140/90 mmhg in spite of the continuous use of three antihypertensive agents in optimal dose, including diuretic, and lifestyle changes. according to data from united states of america and europe, the prevalence ranges from 10 up to 30% in patients with hypertension. numerous biological and lifestyle factors can contribute to the development of resistant hypertension : medications, volume overload, obesity, diabetes mellitus, older age, renal parenchymal and renovascular disease, primary aldosteronism, obstructive sleep apnea, pheochormocytoma, cushing s syndrome, thyroid diseases, aortic coarctation. for diagnosing patient s history is important, assessing compliance, regular blood pressure measurement, physical examination, biochemical evaluation and noninvasive imaging. the evaluation including 24h ambulatory monitoring of blood pressure (abpm) in the identification of non - dipper hypertension. non - dipper has particular importance and the prevalence of abnormally high sleep blood pressure is very often in chronic kidney patients. therapeutic restoration of normal physiologic blood pressure reduction during night - time sleep (circadial variation) is the most significant independent predictor of decreased risk and the basis for the chronotherapy. the resistant hypertension treatment is achieved with nonpharmacological and pharmacological approach, treating secondary hypertension causes and invasive procedures. |
phototherapy, especially psoralen and ultraviolet, is the first - line treatment used widely for the treatment of rare hypopigmented variant of mycosis fungoides. hypopigmented mycosis fungoides (hmf) is an atypical and uncommon variant of mycosis fungoides (mf). psoralen and ultraviolet (puva) is the most widely used method for its treatment and is recommended as the first - line therapeutic modality. narrow - band ultraviolet b (nbuvb) may be tried with same level of evidence and grade of recommendation as puva, thereby providing an alternative, relatively safe, and effective treatment option. a 30-year - old woman presented to the dermatology outpatient with complaint of asymptomatic hypopigmented lesions all over the body. initially, 23 lesions appeared over trunk 5 years back that gradually progressed to involve almost whole of the body sparing face and flexures. she did not have any systemic complaints or weight loss. her general physical examination including lymph node examination was within normal limits. cutaneous examination revealed generalized, multiple well- to ill - defined hypopigmented, nonscaly macules without overlying atrophy or telangiectasia [figure 1 ], sparing face and flexures. skin biopsy revealed slightly thinned out epidermis with single cell infiltration in the basal layer. the lymphoid cells appear enlarged and surrounded by clear halo with increased fibrosis in papillary dermis [figure 2 ]. at higher magnification, infiltrating atypical hyperchromatic lymphoid cells were seen in the epidermis [figure 2 ]. immunohistochemistry revealed numerous t - cells arranged in bead - like fashion in the basal layer of epidermis, with focal clustering with anti - cd3 - 3,3'-diaminobenzidine chromogen [figure 3 ]. her routine hematological and biochemical investigations, radiograph of the chest, and usg of the abdomen revealed no abnormality. she was counseled and started on nbuvb phototherapy, starting with 200 mj / cm that was increased slowly to maximum 2100 mj / cm over 3 months. nbuvb sessions were scheduled initially thrice a week for 3 months (50 sessions), followed by twice weekly for next 3 months. after 66 nbuvb sessions, the patient showed complete clearance of lesions [figure 4 ]. posttreatment biopsy showed unremarkable epidermis with lack of any atypical lymphocytes [figure 5 ], and immunochemistry for cd3 did not show any evidence of epidermotropism. the patient has not shown any evidence of recurrence after 6 months of follow - up. multiple hypopigmented nonscaly macules over buttocks and trunk thinned out epidermis with single cell infiltration in the basal layer. higher power view of epidermis in inset showing infiltrating atypical hyperchromatic lymphoid cells (h and e, 1000) numerous t cells arranged in bead - like fashion in basal layer of epidermis with focal clustering (anti - cd3-dab chromogen, 100) complete clearance of lesions after narrow - band ultraviolet b therapy posttreatment biopsy showing unremarkable epidermis with lack of any atypical lymphocytes (h and e, 400) primary cutaneous lymphomas (pcls) belong to a heterogeneous group of malignant lymphoproliferative neoplasms, affecting primarily skin without any system involvement (visceral, bone marrow, or lymph nodes) at the time of diagnosis. several clinical variants of mf have been described ; hypopigmented, hyperpigmented, ichthyosiform, pityriasis lichenoides - like, granulomatous, folliculotropic, pagetoid reticulosis, purpuric, hyperkeratotic, and verrucous. hmf differs from classic mf in having a relatively younger age of onset with female predominance as was seen in our case ; however, the histologic diagnosis may be delayed until 210 years. hmf is reported almost exclusively in dark - skinned and asian patients as against the classical form. clinically, hmf has asymptomatic, hypopigmented, to achromycin - scaly lesions of varying size distributed chiefly over trunk and proximal parts of extremities (buttocks, pelvic girdle, and trunk), with occasional involvement of distal extremities and head. differential diagnoses include hypopigmented lesion of atopic dermatitis, pityriasis alba, leprosy, vitiligo, postinflammatory hypopigmentation, sarcoidosis, pityriasis lichenoides chronica, pityriasis versicolor, and others. histopathological features of hmf include focal parakeratosis, little or no spongiosis, upper dermal lymphocytic infiltrate with coarse collagen bundles and intense epidermotropism whereas pautrier microabscesses are seldom noted. epidermotropism is predominantly by neoplastic cd4 + t - cells in classical mf and by cd8 + cells in hmf. this finding seems to influence the pathogenesis of hmf as the suppressor phenotype limits the disease progression by preventing cutaneous dissemination and onset of aggressive plaque stage, despite the neoplastic nature of these cells. latter coupled with early diagnosis is responsible for better prognosis of hmf as compared to the classic form. atypical neoplastic cells tend to cause melanocytes degeneration and abnormal melanogenesis resulting in hypopigmented lesions. despite good prognosis, potential lethality of hmf should not be underestimated, and therefore, treatment is desirable. complete clinical assessment, peripheral blood examination, quantification of szary cells and t - lymphocytes using flow cytometry as well imaging studies should be performed to exclude visceral involvement. effective therapeutic modalities for hmf include phototherapy, topical nitrogen mustard, topical carmustine, and total skin electron beam therapy. phototherapy, especially photochemotherapy (puva), is most widely used and is recommended as the first - line treatment. a recent review concluded that puva is a safe, effective, and well - tolerated therapy for early stage mf, stage ia ib, and stage iia (level of evidence 1 +, grade of recommendation b). although the evidence for nbuvb is less robust (level of evidence 2++, grade of recommendation b), it has been considered at least as effective as puva for early - stage mf. maintenance therapy with puva is to be reserved for patients who experience an early relapse. in a recent study, 7/11 patients with hmf achieved complete remission with nbuvb twice weekly (mean of 40 treatments) while remaining 4 had partial remission. relapse was seen in three patients after a mean of 10 months. in another series of nine patients, patients treated with nbuvb, disease recurred after a disease - free interval ranging from 2 months to 6 years. yet, another study reported phototherapy to be effective in 86.7%, with success rate of 66.7% with nbuvb and 80% with puva. there are no standard guidelines for phototherapy for hmf as the disease is uncommon. with wider availability of nbuvb, much better safety profile, and comparable efficacy as that of puva, we propose that nbuvb may be tried in more patients with hmf to arrive at a logistic conclusion. to the best of our knowledge, we report for the first time from india, clinical, histopathological, and immunohistochemical remission, following nbuvb therapy in hmf. nbuvb may be used as a relatively safe and effective therapeutic option in indian scenario for hypopigmented variant of mycosis fungoides. nbuvb may be used as a relatively safe and effective therapeutic option in indian scenario for hypopigmented variant of mycosis fungoides. nbuvb may be used as a relatively safe and effective therapeutic option in indian scenario for hypopigmented variant of mycosis fungoides. | mycosis fungoides (mf) is the most common type of primary cutaneous lymphomas. several clinical variants of mf have been described. purely, hypopigmented variant of mf (hmf) is rare. phototherapy, especially photochemotherapy (psoralen and ultraviolet), is the most widely used method and is recommended as the first - line treatment for hmf. however, there are no standard guidelines for phototherapy as the disease is uncommon. we, hereby, report a 30-year - old woman with hmf in whom clinical, histopathological, and immunohistochemical remission was achieved following narrow - band ultraviolet b therapy. |
steady - state fluorescence emission was measured in bulk using a cary eclipse fluorescence spectrophotometer (agilent technologies) and a low volume cuvette (50 l) (sigma - aldrich). direct excitation of acceptor molecules (cy5) was achieved using an excitation wavelength of 600 nm. the excitation and emission slits were set to 20 nm for the dna origami samples (2 nm in 11 mm mgcl2, buffered with 0.5 tbe) and to 10 nm for the cy3- and cy5-labeled staple strands (500 nm in 1 te), respectively. emission spectra were collected over a wavelength range of 550700 nm upon excitation at 521 nm, and 635700 nm upon excitation at 600 nm, respectively. for each sample, the magnesium chloride titration was performed by stepwise addition of 1 m mgcl2, buffered with 0.5 tbe, to the same cuvette while recording the emission spectra. single - molecule fret measurements of individual diffusing dna origamis were performed in labtek chamber slides (thermo scientific) that were cleaned with 1 m koh and passivated with bsa (10 mg / ml). dna origami structures were diluted in a buffer consisting of 1 pbs, 12.5 mm mgcl2 for stabilization of the origami and 2 mm trolox / troloxquinone, 1% (w / w) glucose, and 10% (v / v) of goc (1 mg / ml glucose oxidase, 0.4% (v / v) catalase (50 g / ml), 30% glycerol, and 12.5 mm kcl in 50 mm tris ph 7.5) for stabilization of the fluorophores. burst measurements were carried out on a custom - built confocal fluorescence microscopy setup. a diode laser with 80 mhz pulse frequency (640 nm, ldh - d - c-640, picoquant) and a 532 nm cw laser (sapphire lp 532 nm 100 mw, coherent) were alternated by an acousto - optical tunable filter (aotfnc - vis, aa optoelectronic) with 100 s period. the laser beams were coupled into an oil - immersion objective (uplansapo 60xo/1.35 na, olympus) that is incorporated in an inverted microscope body (olympus ix-71). the emission light was collected by the same objective and was separated from the excitation light by a dual - band dichroic beam splitter (z532/633 ahf) and focused onto a 50 m pinhole (linos). the emission of cy3 and cy5 was split spectrally by a single - band dichroic mirror (640 dcxr, ahf) and focused onto two avalanche photo diodes (-spad-100, picoquant) with appropriate filtering (cy3 emission, brightline hc582/75, ahf and razoredge lp 532, semrock ; cy5 emission, bandpass et 700/75 m, ahf and razoredge lp 647, semrock). the detector signals were registered with a single photon counting pc card (spc-830, becker & hickl) and evaluated using custom - made labview (national instruments) software (see si methods for details on data analysis). we modeled the energy transfer from the antenna complex to the common acceptor core using a set of rate equations governing the dynamics of the populations of the donor and acceptor chromophores, under external laser excitation and hetero - fret interaction. this treatment assumes that only one particle, one excitonic quasiparticle in this case, is present in the system at any time, which is valid for the low excitation conditions under which the experiments have been carried out. for a single donor acceptor pair, the antenna effect (aead) is given by (see si note s8 for the full derivation)2where d (a) is proportional to the molar extinction coefficient of the donor (acceptor) dye d(d) [d(a) ] dependent on the excitation wavelength d(a) ; see also si note s8, and e(r) the fret efficiency3with r0 the frster radius, that is, the donor acceptor separation corresponding to a fret efficiency e(r) equal to 50%. when more than one donor is present, as in the ring antenna system examined here, the cumulative antenna effect (aetot) simply scales with the total number n of donor dyes di (i = 1,..., n), if these are identical and located at a same distance from the acceptor a4 in this case, we have not considered the homo - fret interaction between identical donors. it can be demonstrated that the energy transfer between identical dyes located at the same distance from the common acceptor does not alter the net antenna effect (si note s8). for two donors d1 and d2 nearly equally spaced from the common acceptor a with distances r1 and r2, respectively, we can introduce an average donor acceptor separation r so that r1 = r + r r2 = r r. in this case, the cumulative antenna effect, aead1+aead2 can be expressed in terms of r (see also si note s10)5where = d/a and = 1/r06. we have used the experimental efficiencies measured by single - molecule spectroscopy (si figure s3), to evaluate the two distinct donor acceptor distances (d1a and d2a). using eq 3 with a frster radius r0 = 5.4 nm the experimental values of the antenna effect as a function of the number of donors (figure 2d) have been fitted using eq 4. in this case, we have assumed an average donor acceptor efficiency e(r), r = (rd1a+rd1a)/2 (see si note s10) and fitted the experimental antenna effects (y) with the linear expression y = x + q, x = ne(r) (n = 1,..., 6) and = d/a. from the linear fit, we get = d/a = 0.606 and q = 0.006. then, with obtained from the linear fit and using r0 = 5.4 nm, we compare the theoretical antenna effect (eq 5) evaluated as a function of the donor acceptor separation (in the two - donor configuration) with the experimental values (see figure 2e). | the remarkable performance and quantum efficiency of biological light - harvesting complexes has prompted a multidisciplinary interest in engineering biologically inspired antenna systems as a possible route to novel solar cell technologies. key to the effectiveness of biological nanomachines in light capture and energy transport is their highly ordered nanoscale architecture of photoactive molecules. recently, dna origami has emerged as a powerful tool for organizing multiple chromophores with base - pair accuracy and full geometric freedom. here, we present a programmable antenna array on a dna origami platform that enables the implementation of rationally designed antenna structures. we systematically analyze the light - harvesting efficiency with respect to number of donors and interdye distances of a ring - like antenna using ensemble and single - molecule fluorescence spectroscopy and detailed frster modeling. this comprehensive study demonstrates exquisite and reliable structural control over multichromophoric geometries and points to dna origami as highly versatile platform for testing design concepts in artificial light - harvesting networks. |
a hip fracture dislocation with contralateral femur fracture is a rare combination, but the incidence is fast growing due to the increased road accidents. femoral head fractures were first described by birkett and fracture dislocations were first described by pipkin. these complex injuries require a prompt multidisciplinary approach and involvement of multiple specialties for successful patient management, but a universal treatment protocol is lacking due to the lack of established studies [24 ]. the majority of femoral head fractures are missed on initial presentation due to unavailability of higher investigative modalities and underdiagnoses, thereby worsening the patient 's condition. we report a case of neglected posterior dislocation of hip with pipkins type ii femoral head and medial condylar fracture associated with a contralateral femoral shaft fracture, an unusual combination which, to the best of our knowledge, has been seldom described. a conscious and oriented 20-year - old male student was brought to casualty following a road traffic accident, 21 days ago where his car hit a tree besides the road, while he was sitting in the front beside the driver. patient received primary treatment at local government hospital and was admitted there, following which patient was brought to our hospital due to dissatisfaction. on arrival, he had a glasgow score of 15, hemodynamically stable with bilateral upper tibial skeletal traction steinmann pins. on examination, right lower limb was adducted, externally rotated with apparent shortening of the right lower limb, whereas the left lower limb was flexed, abducted and externally rotated. gross swelling and bruising was present over both the upper thighs with multiple abrasions. tenderness, crepitus and abnormal bony mobility were present at multiple levels over right thigh and middle of left thigh. passive movements at both the hip and knee were painful and actively not possible bilaterally. multiple abrasions were present over right leg and foot, some of which were infected. patient had a right - sided foot drop with loss of dorsiflexion at right ankle and sensations along the dorsum of leg and foot. x - ray of the pelvis revealed a right posterior hip dislocation with pipkins 's type ii fracture (rt) and ipsilateral distal medial condylar fracture with a fracture shaft of femur (lt) (figs 1 and 2). a ct scan confirmed the infrafoveal right - sided pipkin's - ii fracture of the femoral head (fig. following attempt of closed reduction, ct scan and x - rays revealed incongruous reduction. figure 1:initial x - ray : pelvis with both hips (anteroposterior view). figure 2:initial x - ray : left thigh (anteroposterior view) and right knee (oblique view). figure 3:initial ct scan : pipkin 's fracture (white arrow) with posterior dislocation right hip. initial x - ray : left thigh (anteroposterior view) and right knee (oblique view). initial ct scan : pipkin 's fracture (white arrow) with posterior dislocation right hip. the right hip joint was approached via the kocher - langenbeck approach, fracture site was exposed with removal of fibrous tissue and the fracture involved mostly the infrafoveal non - weight bearing surface of the femoral head (fig. femoral head was fixed with two 4 mm cannulated cancellous screws that were introduced over a guide wire from the non - articular part under c - arm guidance (fig. 5). patient was discharged 2 weeks following operation, then reviewed weekly for 4 weeks, monthly for 1 year and 6 monthly then after. static quadriceps and ankle toe mobilization exercises initiated at 3 postoperative days with frequent side changing. quadriceps wasting of 1.5 cm was managed by quadriceps strengthening exercises, and gradually the tone improved. at 1- and 7-year follow - up, x - rays were satisfactory with no signs of osteonecrosis of femoral head (figs 7 and 8). nail from the left femur and right distal femoral plate were removed at the end of 2 years. the patient at 7 years post - surgery had a good functional assessment (friedman and wyman) score with x - ray bearing no signs of avascular necrosis or heterotrophic ossification, and the fracture had united. over 7 years, patient who is a student by profession is bearing full weight and is successfully performing his personal and social duties. the active range of motion at right hip was 0110 flexion and 010 extension, external rotation 030 with internal rotation 010 with slight loss of terminal abduction (figs 9 and 10). figure 9:clinical photograph at 7-year follow - up (cross leg sitting). incidence of complex femoral fractures are on a rise due to increased road traffic accidents, result in extensive soft tissue injuries with bone comminution resulting in difficult patient management and fracture union problems. accurate diagnosis is essential and requires an anteroposterior view of pelvis including both hips, with oblique and lateral views of the injured hip supplemented by ct / mri scans. immediate reduction is key to prevent complications like avascular necrosis or heterotrophic ossification and to improve prognosis. open reduction and fixation has become primary treatment for hip dislocations associated with femoral head fractures. a literature suggests conservative treatment when the acetabular or femoral head fragments realign to its position and follow reduction of the dislocation and excision of the osteochondral head fragments below the fovea with larger fragments either removed or reduced and fixed using countersunk arbeitgemeinschaft fur osteosynthesfragen (ao group) screws, herbert screws and bioabsorbable pins or even arthroplasty. treatment options for shaft fracture fixation vary from latest reconstruction nails, simultaneous transcervical screwing and shaft plating, retrograde intramedullary nailing with femoral neck - lag screws, reversed intramedullary fixation with cephalomedullary locking with their own surgical difficulties yet operative procedures are not yet standardized and a uniformly accepted treatment algorithm does not exist. the main complications associated are avascular necrosis of the femoral head, heterotopic ossification, peripheral nerve damage and osteoarthritis. osteonecrosis represents a most devastating complication with an incidence range of 6% at an average follow - up of 32 months. although various studies [1, 610 ] report avascular necrosis (avn) and arthritis incidence from 8 to 25% and 12 to 20%, respectively, with pipkin 's fracture discloations, we attribute early congrous or near congrous reduction, anatomical fixation and early rehabilitation in reducing incidence of avn and postoperative arthritis, as seen in this case. radiotherapy and oral indomethacin have both been shown to be of benefit for prophylaxis against heterotopic ossification. to conclude, multiple fractures of femur are difficult to treat. successful diagnosis requires use of ct, mri and ultrasound in adjunct to x - rays. | a hip fracture dislocation with contralateral femur fracture is a rare combination. we report a case of neglected posterior dislocation of hip with pipkins - ii femoral head and medial condylar fractures associated with a contralateral femoral shaft fracture. right hip joint was approached via the kocher - langenbeck, following reduction, femoral head fragments were fixed with two 4-mm cannulated cancellous screws with open reduction internal fixation plating of ipsilateral femoral condylar fracture and closed reduction internal fixation nailing of left femur in the same sitting. immediate postoperative x - rays were satisfactory. postoperative period was uneventful. over 7-year follow - up, patient is successfully performing his duties with x - rays bearing no signs of avascular necrosis (avn) or hip arthritis. thus, complex femoral fractures require a multidisciplinary approach for successful treatment. early congruous reduction, anatomical fixation and early rehabilitation help in reducing the incidence of avn and postoperative arthritis. successful diagnosis of pipkin 's fracture dislocations requires use of ct, mri and ultrasound in adjunct to x - rays. |
nano - sized materials exhibit interesting properties (1) and present new opportunities for a wide range of studies and applications in various areas including physics (2), chemistry (3), biology (4), and medicine (5). use of nanotechnology in various therapeutic sectors has revolutionized the field of medicine, in which nanostructures are used as biomedical tools for investigation (6). common anticancer drugs not only affect cancer cells but also influence normal cells and cause severe side effects. to achieve more effective cancer chemotherapy, it is essential to appropriately select anticancer drugs for the cancer cells. since the complications of anticancer drugs include their impact on normal cells, it is preferred to utilize targeted drug delivery systems. nanoparticulate drug delivery systems such as liposomes (7), polymers (8), nanoparticles (5), dendrimers (9), and carbon nanotubes (10) which contain anticancer agents have received a great deal of attention due to their unique accumulation behaviors in tumor sites. one of the best and ideal solutions for most of the serious problems in chemotherapy is application of drug - loaded nps which have targeting functions (11). np surface is decorated with different ligands that are delivered within cells through receptor - mediated endocytosis. folate (fol), as one of these end ocytosis, has been widely used owing to its many advantages such as small ligand size, convenient availability, low cost, relative simplicity and defined conjugation chemistry, high receptor affinity, absence of normal tissue receptor expression, and therefore high tumor tissue specificity (5, 9 and 12). as a glycosyl phosphatidyl inositol anchored cell surface receptor for folate, folate binding protein is over - expressed in some human tumors ; however, it is widelylimited in normal tissues (13). using folate decorated liposomes, micelles, and nps of biodegradable polymers including poly - lactide - co - glycolide (plga), plga polyethylene glycol (peg), d - alpha - tocopheryl polyethylene glycol 1000 succinate (vitamin e tpgs) folate conjugate, doxorubicin plga vitamin e tpgs conjugate, and plga - peg - fol conjugate as anticancer agents has raised cellular uptake and cell cytotoxicity of the formulated anticancer drugs (5, 9 and 10). in attempts to investigate a suitable nanocarrier system, carbon nanotubes (cnts) have attracted great attention in recent years (10, 14). suitable functionalization is an important factor that affects cytotoxicity and performance of cnts in biological systems (15). in the present work, peg - fa - conjugated smwcnt@fe3o4, which could be used as a multi - targeted drug nanocarrier for delivering an anti - cancer agent to cancer cells with the assistance of an external magnetic field, was prepared and characterized short mwcnts (diameter : 3050 nm, length : 0.5~2 m, purity : > 95%, and ssa : 200 m2/g) were purchased from neutrino nanotechnologies co., iran. ferrous chloride tetrahydrate (fecl2.4h2o, 99 %), ferric chloride hexahydrate (fecl3.6h2o, 99%), sodium hydroxide (naoh), concentrated nitric acid (hno3, 68% v / v), and concentrated sulfuric acid (h2so4, 98% v / v) were purchased from merck co. ltd. poly (ethylene glycol) bis - amine (nh2-peg - nh2, mw : 1500), folic acid, n - hydroxysuccinimide (nhs), and dicyclohexylcarbodiimde (dcc) were obtained from sigma (st. louis, mo). functionalizing carboxylic acid on smwcnts briefly, 90 ml of concentrated h2so4 was added to 1 g of raw smwcnt under stirring. subsequently, 30 ml of concentrated hno3 was added drop - wise to the mixture under sonication. the resulting mixture was refluxed at 110c in an oil bath for 12 h. after dilution with 5-fold water, the solution was filtered through a paper filter (whatman 42) to remove any unreacted bulk of cnts. the added water was evaporated to almost reach the previous volume (120 ml) (10, 14 - 16). neutralizing the solution acidity by base in the previous work, magnetization method of carbon nanotubes the remainder acid could be neutralized with sodium hydroxide in 50 wt% aqueous solution to form sodium sulfate and sodium nitrate salts and water as the end products of the reaction. after reaching ph value up to 11, the mixture containing carboxylated smwcnts (c - smwcnts) was ready for the attachment of fe3o4 nanoparticles (16). attaching fe 3 o 4 nanoparticles to c - smwcnt first, fecl36h2o (420 mg) was dissolved in the mixture under sonication. then, fecl24h2o (153 mg) was dissolved in 6 ml deionized water and added drop - wise to the final mixture under vigorous stirring and nitrogen atmosphere at 80c. after aging for 15 min at the same temperature, then, the product was collected using a strong magnet and washed with deionized water for several times until reaching the ph value of about 7 (16 - 20). preparing peg - fol conjugate in order to activate folic acid carboxylic groups by nhs and dcc, 110 mg of folic acid was dissolved in dmso (5 ml). after dissolving nhs (57 mg), dcc (100 mg), and peg - bis - amine (50 mg) in triethylamine (50 ml), the mixture was stirred under nitrogen atmosphere at room temperature in dark for 24 h. stoichiometric molar ratio of fa / dcc / nhs was 1:2:2. unreacted triethylamine was removed by a rotary evaporator and the resulting product was diluted with 15 ml of deionized water and dialyzed against deionized water for several times (spectra por 6, mw cut off=1000) and then freeze - dried. synthesis scheme of peg - fa conjugate is shown in (figure 1(a)) (5, 14). schematic representation of (a) peg - fa, and (b) peg - fa - smwcnts@fe3o4 conjugate. fabricating peg - fa - smwcnts@fe 3 o 4 first, carboxylic acid groups of 70 mg c - smwcnts@fe3o4 dissolved in 10 ml of phosphate buffer solution (50 mm, ph 6.0) were activated by 160 mg of dcc and 115 mg of nhs at room temperature in dark under nitrogen atmosphere for 6 h. peg - fa (180 mg) was then added to the final mixture for coupling with c - smwcnts@fe3o4 at room temperature in dark under nitrogen atmosphere for 20 h. finally, the product was collected by magnetic separation, followed by three times of washing with deionized water and lyophilized. the synthetic scheme is described in figure 1(b) (5, 10 - 12). sem images of c - smwcnt and c - smwcnt@fe3o4 are shown in figures 2(a) and 2(b). it is obvious that fe3o4 nanoparticles successfully attached to the side walls of c - smwcnt and c - smwcnt@fe3o4 was formed (figure 2(b)). sem images of (a) c - smwcnt, and (b) c - smwcnt@fe3o4 ftir spectra of c - smwcnts are demonstrated in. stretching c = o and c o vibration at 1594.89 and 1213.63 cm and strong stretching peaks of o h at 3396.21 cmindicated that carboxylic acid functional group was generated on the cnt surface(figure 3(a)). a) ftir spectrum of c - smwcnt, and (b) xrd patterns of c - smwcnt@fe3o4 xrd pattern of decorated c - smwcnts with fe3o4 nps is illustrated in (figure 3(b)). diffraction peak at 2=25.99 was ascribed to the reflection of (200) plane of cnt, while the peaks at 2=30.17, 35.76, 42.87, 53.60, 57.52, and 63.35 were related to the (220), (311), (400), (422), (511), and (440) planes of the cubic fe3o4 phase of inverse spinel structure (-). typical room - temperature magnetization curves of magnetic fe3o4 nanoparticles (a) and c - smwcnt@fe3o4 (b) are demonstrated in figures 4(a) and 4(b). saturation magnetization of the pure fe3o4 and c - smwcnt@fe3o4 was 9.86 and 5.83 emu / g, respectively. it can be observed that the saturation magnetization of c - smwcnt@fe3o4 was comparatively less than that of pure fe3o4 nanoparticles, which could be attributed to the presence of cnts in c - smwcnt@fe3o4 sample. the curves exhibited zero remanence and coercivity, which proved that both fe3o4 nanoparticles and c - smwcnt@fe3o4 had super - paramagnetic properties. magnetization curves of (a) fe3o4 nanoparticles, and (b) c - smwcnt@fe3o4 (a) image of peg - fa - smwcnt@fe3o4 with external magnetic field, (b) ftir spectra of peg - fa - smwcnt@fe3o4 the band at 3437.38 cm belonged to hydroxyl (o - h) stretching, while the absorption peak at1475.97 cm was attributed to the characteristic absorption band of phenyl ring. the bands at 2928.47 and 2850.58 cm corresponded to c - h stretching vibrations, while the band at 1626.37 cmbelonged to c = o bond stretching vibration. moreover, the bands at 1574.63 and 3227.40 cmbelonged to the bending and stretching modes of n - h vibration, respectively. the absorption peak at 1088.33 cm was related to the stretching vibration of the c - o - c vibration of peg (20 - 22). b), which shifted to higher wave numbers, confirmed that fe3o4 attached to peg - fa - smwcnt and peg - fa - smwcnt@fe3o4 was formed. previous studies have approved the concept of forming nps with a steric peg barrier which could prevent their rapid uptake by mononuclear phagocyte system and promote their circulatory half - life (12, 16). more recent investigations have demonstrated that rapid res uptake of nps could be significantly reduced by changing their surface with poly (ethylene glycol) (peg). peg - modified nps that are mostly prepared using a di - block copolymer of plga - b - peg, liposome - peg, dendrimer - peg as an additive considerably prolong their half - life in the circulation owing to the presence of highly mobile and flexible peg chains on the surface (16). thus, the main reason for the attachment of peg, fol, and iron to carbon nanotubes could be preparing a novel nanocarrier with surface modification which could increase the potential for delivering anticancer drugs to the tumor site. this finding is in line with those of previous works (10, 12, 16, 23). this study focused on functionalizing carboxylic acid groups on smwcnts (c - smwcnts), neutralizing the remainder acid of the solution by naoh base to reach a ph value of up to 11, decorating c - smwcnts with magnetite (fe3o4) nanoparticles (c - smwcnts@fe3o4), and functionalizing c - smwcnts@fe3o4 with peg - folic acid conjugated (peg - fa- smwcnts@fe3o4). in accordance with obtained resultssuccess of the fully efficient, simple, and short - term method in attaching fe3o4 to the surface of carbon nanotubes was confirmed using scanning electron microscopy, fourier transform infrared spectroscopy, and x - ray diffraction spectroscopy. ftir analysis also was used to investigate the link between peg - fa and smwcnts@fe3o4. | multifunctional nanomaterials showed great advantages in drug delivery. folic acid (fa) binding protein, a glycosyl phosphatidyl inositol anchored cell surface receptor for folate, is overexpressed in several human tumors, whereas it is highly restricted in normal tissues. therefore, in this study, fa, polyethylene glycol (peg), and fe3o4 nanoparticles multifunctionalized short multiwall carbon nanotubes (peg - fa - smwcnt@fe3o4) were synthesized by conjugating folate, peg, and magnetite nanoparticles with carboxylated multiwall carbon nanotubes. the prepared c - smwcnt@fe3o4 was characterized by x - ray diffraction (xrd) and vibrating sample magnetometer (vsm) in order to investigate crystal and magnetic properties, respectively. the images obtained by scanning electron microscopy (sem) showed that the magnetite nanoparticles were attached to the surfaces of carbon nanotubes and smwcnt@fe3o4 was formed. investigation of functional groups using fourier transform infrared (ftir) spectra indicated that peg - fa was successfully linked to smwcnt@fe3o4. |
therefore, androgen deprivation therapy (adt) is one of most effective systemic palliative treatments for such carcinomas. although adt is initially extremely effective, serum prostate - specific antigen (psa) levels increase over time, and the disease eventually becomes characteristic of hormone - refractory prostate cancer (hrpc). several types of treatment have been applied to treat hrpc, including antiandrogen alternation, supplemental steroid therapy, and generalized chemotherapy with docetaxel hydrate (dtx) [3, 4 ]. however, these therapeutic modalities have only a short - term effect. in addition, hrpc is occasionally encountered with locally recurring carcinoma and uncontrolled gross hematuria, dysuria, and scalding. treatment with intra - arterial infusion chemotherapy using cisplatin (cddp) and ifosfamide (ifm) removed the symptom for a considerable period. a 64-year - old japanese man was admitted to hospital with lower urinary tract symptom (luts) and a high psa level (180 ng / ml) in april 1997. he was diagnosed with prostate cancer (moderately differentiated adenocarcinoma, t3bn1m0, stage d1) and was started on combined androgen blockade (cab) with leuprorelin acetate (11.25 mg/3 months) and flutamide (375 mg / day). two months later, flutamide was discontinued because of liver damage, and treatment was switched to estramustine phosphate (emp) sodium (626.8 mg / day). six months after starting hormonal therapy, metastatic lymph node lesion and seminal vessel invasion was no longer visible on computed tomography (ct). therefore, we performed radical prostatectomy (moderately differentiated adenocarcinoma, gleason score 4 + 3 = 7, ly, v, pn, sv, pw, dw, cap, n) and obturator lymph node excision to completely remove the cancerous lesion. the patient received adjuvant radiation therapy (60 gy) to the pelvic cavity postoperatively because pathological findings showed the prostatic carcinoma had extended beyond the prostate capsule. additionally, a course of chemotherapy with cyclophosphamide (cpm), doxorubicin hydrochloride (adm), and cddp (cpm 500 mg, adm 50 mg, cddp 100 thereafter, the patient was followed up with hormonal therapy consisting of leuprorelin acetate (11.25 mg/3 months) and emp (626.8 mg / day). in june 2002, however, psa value continued to increase (13.74 ng / ml) in december 2004 ; magnetic resonance imaging (mri, fig. 1) and transrectal biopsy was performed, and we diagnosed a recurrence of prostatic carcinoma (moderately differentiated adenocarcinoma, gleasen score, 4 + 4 = 8). whole - body ct and bone scintigraphy showed no abnormal findings. as a result, 1magnetic resonance imaging (mri) shows anastomotic recurrence after radical prostatectomy and radiation therapy magnetic resonance imaging (mri) shows anastomotic recurrence after radical prostatectomy and radiation therapy we then decided to attempt intra - arterial infusion chemotherapy to treat the local recurrence. an indwelling catheter was placed in the bilateral internal iliac artery, and the pump was placed in a subcutaneous pocket in february 2005. the combination chemotherapy consisted of cddp (20 mg / m) (days 15) and ifm (1.2 mg / m) (days 13), and its regimen cycle was every 21 days. the patient received two courses of chemotherapy, after which his psa value decreased to 1.94 ng / ml, the tumor showed a remarkable reduction in size (fig. 2), and the symptom improved. in this case, grade 3 neutropenia (which was improved by granulocyte - colony stimulating factor), vomiting, general fatigue, and grade 3 alopecia were observed. however, other serious side effects that could pose a risk to continued intra - arterial infusion chemotherapy were not observed.. however, psa value gradually increased to 4.61 ng / ml in april 2006. we once again attempted intra - arterial infusion chemotherapy of cddp and ifm with the same dose as previously used (fig. at a later time, the psa value once again rose from the value in may 2007. however, the patient had no symptoms of luts for 45 months after the first chemotherapy treatment.fig. 2magnetic resonance imaging (mri shows disappearance of the anastomotic tumor after intra - arterial infusion chemotherapyfig. 3progress of psa treatment and transition values magnetic resonance imaging (mri shows disappearance of the anastomotic tumor after intra - arterial infusion chemotherapy progress of psa treatment and transition values treating hrpc is troublesome for a urologist because the standard treatment has not yet been established. in addition, hrpc patients occasionally have luts, such as urinary retention and dysuria accompanied with gross hematuria, which adversely affects quality of life. here, we reported a case of urinary retention due to locally recurrent hrpc in which retention was improved by intra - arterial infusion of cddp and ifm. according to the established criteria for evaluating outcomes of nonsurgical therapy for prostate cancer, the prostatic lesions of the case showed a partial response (pr). however, on the basis of psa responses, the patient showed complete response (cr). at present, hrpc treatments, such as antiandrogen alteration, systemic chemotherapy with dtx [3, 4 ], and low - dose steroids, are effective in the short term, but their effectiveness decreases over time. various generalized combination chemotherapies have been tried for hrpc, but no reports of their long - term efficacy are available [510 ]. in the 1990s, intra - arterial chemotherapies for hrpc were reported, which indicated that, whereas they were effective for local carcinostatics, they were not effective as a generalized treatment modality [1113 ]. in the study reported here, because we encountered locally recurring hrpc with luts, we thought it may be worthwhile to try intra - arterial chemotherapy for relieving luts caused by hrpc. our cases suggest that intra - arterial chemotherapy may be a good choice for treating hrpc with locally recurring hrpc only. however, the problem with this therapy is that it does not radically treat the cancer. in addition, it should not be administered in cases with poor performance status or prognosis. dtx could be used as a second - line intra - arterial chemotherapy treatment after cddp and ifm, because intra - arterial dtx accompanied with cddp for oropharyngeal cancer is reported to result in an excellent primary response rate and acceptable acute toxicity. in conclusion, intra - arterial chemotherapy with cddp and ifm can alleviate luts caused by locally recurrent hrpc. accordingly, this regimen should be seen as a treatment option for locally recurrent hrpc. as the number of prostate cancer cases increases, urologists are likely to encounter more patients who are suitable for such treatment. | although many treatments have been applied to treat hormone - refractory prostate cancer (hrpc), therapeutic outcome is not altogether satisfactory. in the case of locally recurring hrpc, uncontrolled gross hematuria, dysuria, and scalding are often experienced. we report a patient who improved following intra - arterial infusion of cisplatin (cddp) and ifosfamide (ifm) to treat urinary retention caused by locally recurring hrpc. after chemotherapy, cancer volume was remarkably reduced and symptoms improved. |
gad - tg mice were generated by microinjecting nod mouse oocytes with a dna construct consisting of an mhcii enhancer / invariant chain promoter linked to a mouse gad65 cdna (14). the gad - tg mice were bred with nod mice (jackson labs), producing gad - tg offspring that were heterozygous for the transgene or that were nontransgenic nod mice. the presence of the transgene was detected by pcr analysis of tail dna (14). the autoantigenic and immunodominant gad65 peptides that were tested included gad(524543) (also termed gadp35 ; srlskvapvikarmmeygtt), gad(217236) (also termed gadp15 ; eyvtlkkmreiigwpggsgd) (1,19,20), and gad(206220) (tyeiapvfvlleyvt) (21). two peptides containing absolute gad65 cryptic determinants, which are immunogenic but ignored by the spontaneous autoimmune response in nod mice, were also tested : gad(260279) (also known as gadp18, pevkekgmaalprliaftse) and gad(398420) (also known as gadp27, vplqcsallvreeglmoncnq) (22). peptides from other key -cell autoantigens included the immunodominant peptide of the 65-kda heat shock protein, termed hspp277 (vlgggcallrcipaldsltpaned) (23) and insulin b - chain (sigma) (2226). an immunogenic hen egg lysozyme (hel) peptide (1125), amkrhgldnyrgysl (27), was used as a control foreign peptide. mouse myelin basic protein (mbp) (sigma) was further purified as previously described (28) and used as a control self - antigen not involved in the autoimmune response. all peptides were synthesized by bio - synthesis (lewisville, tx) at 95% purity. briefly, pancreata from individual nod or gad - tg mice at the indicated ages were removed and digested with collagenase and dnase i. pancreatic lymph nodes were obtained by hand picking. mononuclear cells were isolated and counted, and only preparations with > 95% viability were used. the frequency of antigen - specific interferon (ifn)-, interleukin (il)-4, and il-5secreting t - cells was determined using a modified elispot technique and optimal antigen concentrations as previously described (29,32,33). briefly, 10 splenic mononuclear cells or 10 pln mononuclear cells from individual mice together with 10 irradiated (3,000 rads) splenic mononuclear cells were added to individual wells in duplicate in an elispot plate that had been coated with cytokine capture antibodies and incubated with peptide (20 mol / l), gad65 (100 g), or islet lysate (from 40 islets) overnight for ifn- or 40 h for il-4 and il-5 detection. after washing, biotinylated detection antibodies were added and the plates were incubated at 4c overnight. antibodies r4 - 6a2/xmg 1.2-biotin, 11b11/bvd6 - 24g2-biotin, and trfk5/trfk4-biotin (pharmingen) were used for capture and detection of ifn-, il-4, and il-5, respectively. all assays were done in duplicate or triplicate, and data are from two to three independent experiments. after 12 weeks of age, gad - tg and control nod mice were monitored weekly for the development of diabetes by testing their blood glucose levels. two consecutive levels of blood glucose > 250 mg / dl was considered onset of diabetes. the difference between gad - tg and wild - type nod mice was statistically analyzed by student 's t test. the autoantigenic and immunodominant gad65 peptides that were tested included gad(524543) (also termed gadp35 ; srlskvapvikarmmeygtt), gad(217236) (also termed gadp15 ; eyvtlkkmreiigwpggsgd) (1,19,20), and gad(206220) (tyeiapvfvlleyvt) (21). two peptides containing absolute gad65 cryptic determinants, which are immunogenic but ignored by the spontaneous autoimmune response in nod mice, were also tested : gad(260279) (also known as gadp18, pevkekgmaalprliaftse) and gad(398420) (also known as gadp27, vplqcsallvreeglmoncnq) (22). peptides from other key -cell autoantigens included the immunodominant peptide of the 65-kda heat shock protein, termed hspp277 (vlgggcallrcipaldsltpaned) (23) and insulin b - chain (sigma) (2226). an immunogenic hen egg lysozyme (hel) peptide (1125), amkrhgldnyrgysl (27), was used as a control foreign peptide. mouse myelin basic protein (mbp) (sigma) was further purified as previously described (28) and used as a control self - antigen not involved in the autoimmune response. all peptides were synthesized by bio - synthesis (lewisville, tx) at 95% purity. briefly, pancreata from individual nod or gad - tg mice at the indicated ages were removed and digested with collagenase and dnase i. pancreatic lymph nodes were obtained by hand picking. mononuclear cells were isolated and counted, and only preparations with > 95% viability were used. the frequency of antigen - specific interferon (ifn)-, interleukin (il)-4, and il-5secreting t - cells was determined using a modified elispot technique and optimal antigen concentrations as previously described (29,32,33). briefly, 10 splenic mononuclear cells or 10 pln mononuclear cells from individual mice together with 10 irradiated (3,000 rads) splenic mononuclear cells were added to individual wells in duplicate in an elispot plate that had been coated with cytokine capture antibodies and incubated with peptide (20 mol / l), gad65 (100 g), or islet lysate (from 40 islets) overnight for ifn- or 40 h for il-4 and il-5 detection. after washing, biotinylated detection antibodies were added and the plates were incubated at 4c overnight. antibodies r4 - 6a2/xmg 1.2-biotin, 11b11/bvd6 - 24g2-biotin, and trfk5/trfk4-biotin (pharmingen) were used for capture and detection of ifn-, il-4, and il-5, respectively. all assays were done in duplicate or triplicate, and data are from two to three independent experiments. after 12 weeks of age, gad - tg and control nod mice were monitored weekly for the development of diabetes by testing their blood glucose levels. two consecutive levels of blood glucose > 250 mg / dl was considered onset of diabetes. data are presented as means sem. the difference between gad - tg and wild - type nod mice because the environment can affect type 1 diabetes incidence in nod mice, we examined the kinetics of type 1 diabetes development in the newly established gad - tg mouse colony at the university of california los angeles. as in the previous study of gad - tg mice (14), we observed that gad - tg mice and their nontransgenic nod mouse littermates developed type 1 diabetes at similar rates (fig. 1), although the onset of type 1 diabetes was somewhat delayed in our mice relative to the previous study. gad - tg and nontransgenic nod mouse littermates have similar incidence of diabetes in our colonies at the university of california los angeles. gad - tg mice, n = 10 ; nod mice, n = 11. we analyzed the functional phenotype and frequency of antigen - specific autoreactive t - cell responses to gad65 in gad - tg mice and their nod littermates directly ex vivo by an elispot assay. previous studies have shown that th1 responses to gad65 are detected in the spleen of 3- to 4-week - old nod mice, and t - cell autoimmunity to insulin b - chain and hspp277 become detectable after 68 weeks of age (1,2,29). we therefore examined t - cell responses to these autoantigens in 8-week - old gad - tg mice, by which time t - cell responses to gad, hspp277, and insulin b - chain should have been well established. we detected an average frequency of 159/10 ifn-secreting splenic mononuclear cells t - cells reactive to whole gad65 in nod mice (fig. 2a), consistent with previous studies (1,20,29). in gad - tg mice, the frequency of splenic gad65-reactive ifn-secreting t - cells was reduced to 12/10 (8% of that in age - matched nod mice) (fig. 2a), similar to the previous assessment of their tolerance to gad65 using gad65 immunization and recall response testing (14). reduced th1 responses to gad65 and its dominant determinants without spreading of autoreactivity to its cryptic determinants or induction of th2 responses. a : the frequency of ifn-, il-4, and il-5secreting t - cells responding to whole gad65 in the spleen of 8-week - old gad - tg and nontransgenic nod mouse littermates was analyzed directly ex vivo by elispot assays. the mean number of ifn-secreting spot - forming cells (sfcs) sem per million spleen cells is shown. we did not detect any il-4 or il-5secreting splenic t - cells responding to gad65 in the spleens of nod or gad - tg mice (data not shown). b : the frequency of ifn-secreting splenic t - cells responding to peptides containing dominant determinants gad(524543), gad(217236), and gad(206220), as well as absolute cryptic determinants gad(60279) and gad(398420), which are immunogenic but ignored by the autoimmune response (22) and control peptide hel (1125). we did not detect il-4 responses to these peptides (data not shown). data shown are averages from four to five mice individually analyzed in duplicate in two separate experiments. we did not detect any il-4 or il-5secreting splenic t - cells responding to gad65 in nod mice, consistent with previous studies (20,29) ; we also did not detect any il-4 or il-5 responses in the spleens of gad - tg mice (data not shown). these data suggest that expression of gad65 in professional apcs did not shift the functional phenotype of spontaneous t - cell autoreactivities to gad65. gad65 expression by professional apcs in gad - tg mice should enforce passive tolerance to the dominant determinants of gad65 that are well presented after antigen processing. previous studies have shown that induction of passive tolerance to a dominant determinant of a -cell autoantigen can enhance t - cell responses to its subdominant and cryptic determinants (15), which can be detected by testing t - cell responses to antigenic peptides, since the determinants are poorly presented from whole protein (18). we tested whether expression of gad65 in professional apcs modulated spontaneous t - cell responses to gad65 antigenic peptides containing dominant determinants gad(524543), gad(217236), and gad(206220) (1,20,21,29,34) and two absolute cryptic determinants gad(260279) and gad(398420), which are immunogenic but ignored by spontaneous autoimmune responses in nod mice (22). we found that the frequency of ifn-secreting t - cells recognizing gad(524543), gad(206220), and gad(217236) in 8-week - old gad - tg mice were reduced to 14, 13, and 18%, respectively, of that detected in the spleens of nod mouse littermates (fig. it is likely that some t - cell responses also remain to many other gad65 autoantigenic determinants that we did not test. we did not detect il-4 and il-5 responses to the gad65 peptides (data not shown), again suggesting that increased presentation of the dominant / subdominant determinants did not alter the functional phenotype of their cognate effectors. we also did not detect t - cell responses to gad65 cryptic determinants in nod mice, consistent with previous observations (22), nor in gad - tg mice (fig. thus, in contrast to observations in studies of other -cell autoantigens (35), induction of passive tolerance to gad65 's dominant determinants did not enhance t - cell autoimmunity to its cryptic determinants in our experimental system. we next examined the impact of reduced gad65 autoimmunity on the development of t - cell autoreactivities to the immunodominant determinants of other -caas, namely, insulin b - chain and hspp277, in young gad - tg mice. while we detected frequent splenic ifn-secreting t - cell responses to insulin b - chain and hspp277 in 8-week - old nod mice, th1 responses to insulin b - chain and hspp277 in the spleen and pln of age - matched gad - tg mice for example, splenic t - cell responses to hspp277 and insulin b - chain were 14 and 56% of those, respectively, in nod mice (p < 0.01 for both, fig. 3a and b). moreover, splenic and pln responses to islet lysate were also significantly reduced (p < 0.05 for both). the responses to islet lysate were not as greatly reduced as those to hspp277 and insulin b - chain. this may be because the islet lysate is comprised of thousands of whole proteins each at different concentrations such that -caas are not at their optimal concentrations for elispot detection. in contrast, the insulin b - chain and hspp277 peptides contain a major autoantigenic determinant, are readily presented, and are at an optimal concentration in the elispot assay, providing a more sensitive readout. we did not detect il-4 and il-5secreting splenic t - cells responding to gad, insulin b - chain, or hspp277, as in previous studies (28,29) (data not shown) in either strain of mouse. as expected, t - cell responses to control mbp were at background levels in the spleen and pln. we did not test even younger gad - tg mice for t - cell responses to insulin b - chain and hspp277, as previous studies have shown that these responses first arise in nod mouse spleen at 68 weeks of age (1,2,20). thus, induced passive tolerance to gad65 curtailed the early activation and expansion of autoreactive th1 cells responding to other -caas in gad - tg mice. the reduced t - cell autoreactivities to -caas in young gad - tg mice suggests that at early stages of the disease process, activated -caa reactive t - cells are interdependent for support to activate and expand. the frequency of splenic (a) ifn-secreting t - cell responses to hspp277, insulin b - chain, mbp, and islet lysate in 8-week - old gad - tg mice were reduced relative to their nontransgenic nod mouse littermates. (b) pln responses to hspp277, insulin b - chain, and islet lysate were also significantly reduced in gad - tg mice. we did not detect il-4 or il-5secreting splenic t - cells responding to these antigens in either strain of mouse (data not shown). the mean number of ifn-secreting sfc sem per 10 spleen cells, or per 10 pln mononuclear cells, is shown. p < 0.05, p < 0.01. the significantly reduced t - cell autoimmunity to -caas in young gad - tg mice was enigmatic, since gad - tg mice develop type 1 diabetes at the same rate as nod mice. we therefore examined t - cell autoreactivities to -caas at later stages of the disease process in gad - tg mice. we found that at 12 weeks of age, the frequency of ifn-secreting t - cells responding to gad65 in the spleen and pln remained at low levels (fig. 4a and b). however, in contrast to the reduced levels of t - cell autoreactivities to hspp277 and insulin b - chain in young gad - tg mice, we observed significantly higher levels of t - cell autoreactivity to hspp277 and insulin b - chain in older gad - tg mice. at 12 weeks of age, splenic t - cells responding to hspp277 and insulin b - chain in gad - tg mice were on average 137 and 121% more frequent, respectively, than in their nod mouse littermates (p < 0.05 for both) (fig. significantly greater th1 responses to insulin b - chain and hspp277 were also observed in the spleen of 16-week - old gad - tg mice (p < 0.01 and 0.05, respectively) (fig. 4c). therefore, induction of tolerance to gad65 led to supernormal frequencies of -caa reactive t - cells in the spleen of older gad - tg mice. enhanced autoreactivities to other -caas in older gad - tg mice. the frequency of t - cell responses to hspp277, insulin b - chain, mbp, and islet lysate were tested at 12 weeks of age (a and b) and at 16 weeks of age (c and d) in the spleen (a and c) and pln (b and d) of gad - tg mice and age - matched nod mouse littermates. while the frequency of t - cells responding to whole gad65 remained greatly reduced in gad - tg mice, splenic t - cell responses to hspp277 and insulin b - chain were significantly increased at 12 weeks of age, as were pln t - cell responses. t - cell responses to hspp277 and insulin b - chain were also supernormal in the spleen and pln of 16-week - old gad - tg mice. importantly, t - cell autoimmunity to other -caas was also expanded in the pln of gad - tg mice. at 12 weeks of age, pln t - cell responses against insulin b - chain had expanded to a greater extent than observed in the spleen and were on average 202% more frequent than those in the pln of their nod mouse littermates (p < 0.01) (fig. the t - cell responses against hspp277 in the pln population of gad - tg mice were increased by 131% (p < 0.01). at 16 weeks of age, supernormal t - cell responses were again observed in the pln, with responses to insulin b - chain and hspp277 166 and 133%, respectively, greater than those in nod mice (p < 0.01 and 0.05, respectively) (fig. 4d). we did not detect il-4 and il-5 t - cell responses to these -caas (data not shown). thus, while partial gad65 tolerization initially impaired the activation and expansion of autoreactive t - cells recognizing other -caas, it led to supernormal t - cell autoreactivities to other -caas in the spleen and pln later in the disease process. we also analyzed spleen and pln t - cell responses to an islet lysate from nod.scid mice. while these responses were significantly reduced in 8-week - old gad - tg mice, in both 12- and 16-week - old gad - tg mice the frequency of spleen and pln ifn-secreting t - cell responses to the islet lysate increased to essentially the same level as that in their age - matched nod mouse littermates (fig. 4). this may explain why the ectopic gad65 expression in apcs had no discernable effect on the disease kinetics of gad - tg mice. because the environment can affect type 1 diabetes incidence in nod mice, we examined the kinetics of type 1 diabetes development in the newly established gad - tg mouse colony at the university of california los angeles. as in the previous study of gad - tg mice (14), we observed that gad - tg mice and their nontransgenic nod mouse littermates developed type 1 diabetes at similar rates (fig. 1), although the onset of type 1 diabetes was somewhat delayed in our mice relative to the previous study. gad - tg and nontransgenic nod mouse littermates have similar incidence of diabetes in our colonies at the university of california los angeles. gad - tg mice, n = 10 ; nod mice, n = 11. we analyzed the functional phenotype and frequency of antigen - specific autoreactive t - cell responses to gad65 in gad - tg mice and their nod littermates directly ex vivo by an elispot assay. previous studies have shown that th1 responses to gad65 are detected in the spleen of 3- to 4-week - old nod mice, and t - cell autoimmunity to insulin b - chain and hspp277 become detectable after 68 weeks of age (1,2,29). we therefore examined t - cell responses to these autoantigens in 8-week - old gad - tg mice, by which time t - cell responses to gad, hspp277, and insulin b - chain should have been well established. we detected an average frequency of 159/10 ifn-secreting splenic mononuclear cells t - cells reactive to whole gad65 in nod mice (fig. 2a), consistent with previous studies (1,20,29). in gad - tg mice, the frequency of splenic gad65-reactive ifn-secreting t - cells was reduced to 12/10 (8% of that in age - matched nod mice) (fig. 2a), similar to the previous assessment of their tolerance to gad65 using gad65 immunization and recall response testing (14). reduced th1 responses to gad65 and its dominant determinants without spreading of autoreactivity to its cryptic determinants or induction of th2 responses. a : the frequency of ifn-, il-4, and il-5secreting t - cells responding to whole gad65 in the spleen of 8-week - old gad - tg and nontransgenic nod mouse littermates was analyzed directly ex vivo by elispot assays. the mean number of ifn-secreting spot - forming cells (sfcs) sem per million spleen cells is shown. we did not detect any il-4 or il-5secreting splenic t - cells responding to gad65 in the spleens of nod or gad - tg mice (data not shown). b : the frequency of ifn-secreting splenic t - cells responding to peptides containing dominant determinants gad(524543), gad(217236), and gad(206220), as well as absolute cryptic determinants gad(60279) and gad(398420), which are immunogenic but ignored by the autoimmune response (22) and control peptide hel (1125). we did not detect il-4 responses to these peptides (data not shown). data shown are averages from four to five mice individually analyzed in duplicate in two separate experiments. we did not detect any il-4 or il-5secreting splenic t - cells responding to gad65 in nod mice, consistent with previous studies (20,29) ; we also did not detect any il-4 or il-5 responses in the spleens of gad - tg mice (data not shown). these data suggest that expression of gad65 in professional apcs did not shift the functional phenotype of spontaneous t - cell autoreactivities to gad65. gad65 expression by professional apcs in gad - tg mice should enforce passive tolerance to the dominant determinants of gad65 that are well presented after antigen processing. previous studies have shown that induction of passive tolerance to a dominant determinant of a -cell autoantigen can enhance t - cell responses to its subdominant and cryptic determinants (15), which can be detected by testing t - cell responses to antigenic peptides, since the determinants are poorly presented from whole protein (18). we tested whether expression of gad65 in professional apcs modulated spontaneous t - cell responses to gad65 antigenic peptides containing dominant determinants gad(524543), gad(217236), and gad(206220) (1,20,21,29,34) and two absolute cryptic determinants gad(260279) and gad(398420), which are immunogenic but ignored by spontaneous autoimmune responses in nod mice (22). we found that the frequency of ifn-secreting t - cells recognizing gad(524543), gad(206220), and gad(217236) in 8-week - old gad - tg mice were reduced to 14, 13, and 18%, respectively, of that detected in the spleens of nod mouse littermates (fig. it is likely that some t - cell responses also remain to many other gad65 autoantigenic determinants that we did not test. we did not detect il-4 and il-5 responses to the gad65 peptides (data not shown), again suggesting that increased presentation of the dominant / subdominant determinants did not alter the functional phenotype of their cognate effectors. we also did not detect t - cell responses to gad65 cryptic determinants in nod mice, consistent with previous observations (22), nor in gad - tg mice (fig. thus, in contrast to observations in studies of other -cell autoantigens (35), induction of passive tolerance to gad65 's dominant determinants did not enhance t - cell autoimmunity to its cryptic determinants in our experimental system. we next examined the impact of reduced gad65 autoimmunity on the development of t - cell autoreactivities to the immunodominant determinants of other -caas, namely, insulin b - chain and hspp277, in young gad - tg mice. while we detected frequent splenic ifn-secreting t - cell responses to insulin b - chain and hspp277 in 8-week - old nod mice, th1 responses to insulin b - chain and hspp277 in the spleen and pln of age - matched gad - tg mice for example, splenic t - cell responses to hspp277 and insulin b - chain were 14 and 56% of those, respectively, in nod mice (p < 0.01 for both, fig. 3a and b). moreover, splenic and pln responses to islet lysate were also significantly reduced (p < 0.05 for both). the responses to islet lysate this may be because the islet lysate is comprised of thousands of whole proteins each at different concentrations such that -caas are not at their optimal concentrations for elispot detection. in contrast, the insulin b - chain and hspp277 peptides contain a major autoantigenic determinant, are readily presented, and are at an optimal concentration in the elispot assay, providing a more sensitive readout. we did not detect il-4 and il-5secreting splenic t - cells responding to gad, insulin b - chain, or hspp277, as in previous studies (28,29) (data not shown) in either strain of mouse. as expected, t - cell responses to control mbp were at background levels in the spleen and pln. we did not test even younger gad - tg mice for t - cell responses to insulin b - chain and hspp277, as previous studies have shown that these responses first arise in nod mouse spleen at 68 weeks of age (1,2,20). thus, induced passive tolerance to gad65 curtailed the early activation and expansion of autoreactive th1 cells responding to other -caas in gad - tg mice. the reduced t - cell autoreactivities to -caas in young gad - tg mice suggests that at early stages of the disease process, activated -caa reactive t - cells are interdependent for support to activate and expand. the frequency of splenic (a) ifn-secreting t - cell responses to hspp277, insulin b - chain, mbp, and islet lysate in 8-week - old gad - tg mice were reduced relative to their nontransgenic nod mouse littermates. (b) pln responses to hspp277, insulin b - chain, and islet lysate were also significantly reduced in gad - tg mice. we did not detect il-4 or il-5secreting splenic t - cells responding to these antigens in either strain of mouse (data not shown). the mean number of ifn-secreting sfc sem per 10 spleen cells, or per 10 pln mononuclear cells, is shown. the significantly reduced t - cell autoimmunity to -caas in young gad - tg mice was enigmatic, since gad - tg mice develop type 1 diabetes at the same rate as nod mice. we therefore examined t - cell autoreactivities to -caas at later stages of the disease process in gad - tg mice. we found that at 12 weeks of age, the frequency of ifn-secreting t - cells responding to gad65 in the spleen and pln remained at low levels (fig. 4a and b). however, in contrast to the reduced levels of t - cell autoreactivities to hspp277 and insulin b - chain in young gad - tg mice, we observed significantly higher levels of t - cell autoreactivity to hspp277 and insulin b - chain in older gad - tg mice. at 12 weeks of age, splenic t - cells responding to hspp277 and insulin b - chain in gad - tg mice were on average 137 and 121% more frequent, respectively, than in their nod mouse littermates (p < 0.05 for both) (fig. significantly greater th1 responses to insulin b - chain and hspp277 were also observed in the spleen of 16-week - old gad - tg mice (p < 0.01 and 0.05, respectively) (fig. induction of tolerance to gad65 led to supernormal frequencies of -caa reactive t - cells in the spleen of older gad - tg mice. enhanced autoreactivities to other -caas in older gad - tg mice. the frequency of t - cell responses to hspp277, insulin b - chain, mbp, and islet lysate were tested at 12 weeks of age (a and b) and at 16 weeks of age (c and d) in the spleen (a and c) and pln (b and d) of gad - tg mice and age - matched nod mouse littermates. while the frequency of t - cells responding to whole gad65 remained greatly reduced in gad - tg mice, splenic t - cell responses to hspp277 and insulin b - chain were significantly increased at 12 weeks of age, as were pln t - cell responses. t - cell responses to hspp277 and insulin b - chain were also supernormal in the spleen and pln of 16-week - old gad - tg mice., t - cell autoimmunity to other -caas was also expanded in the pln of gad - tg mice. at 12 weeks of age, pln t - cell responses against insulin b - chain had expanded to a greater extent than observed in the spleen and were on average 202% more frequent than those in the pln of their nod mouse littermates (p < 0.01) (fig. the t - cell responses against hspp277 in the pln population of gad - tg mice were increased by 131% (p < 0.01). at 16 weeks of age, supernormal t - cell responses were again observed in the pln, with responses to insulin b - chain and hspp277 166 and 133%, respectively, greater than those in nod mice (p < 0.01 and 0.05, respectively) (fig. we did not detect il-4 and il-5 t - cell responses to these -caas (data not shown). thus, while partial gad65 tolerization initially impaired the activation and expansion of autoreactive t - cells recognizing other -caas, it led to supernormal t - cell autoreactivities to other -caas in the spleen and pln later in the disease process. we also analyzed spleen and pln t - cell responses to an islet lysate from nod.scid mice. while these responses were significantly reduced in 8-week - old gad - tg mice, in both 12- and 16-week - old gad - tg mice the frequency of spleen and pln ifn-secreting t - cell responses to the islet lysate increased to essentially the same level as that in their age - matched nod mouse littermates (fig. 4). this may explain why the ectopic gad65 expression in apcs had no discernable effect on the disease kinetics of gad - tg mice. our characterization of t - cell autoreactivities in nod gad - tg mice, which ectopically express gad65 in professional apcs, revealed unexpected changes in the dynamics of their autoimmune responses. we observed that in gad - tg mice, autoimmune responses to whole gad65 at 8, 12, and 16 weeks of age were 810% of those in age - matched nod mouse littermates and that both strains of mice had similar rates of type 1 diabetes incidence, consistent with the initial characterization of these mice (14). t - cell responses to peptides containing gad65 dominant determinants [gad(524543), gad(206220), and gad(217236) ] were somewhat stronger, ranging from 13 to 18% of those in age - matched nod mice. the detection of more frequent th1 cell responses to synthetic peptides of gad65 was likely due to circumventing whole antigen processing and using optimal peptide concentrations in our in vitro elispot assays. since gad65 is a fairly large protein with many autoantigenic determinants that we did not test, the total remaining t - cell responses to gad65 determinants in these mice is still substantial. accordingly, it is not possible to draw conclusions from these mice as to whether gad65 autoreactivity is required for the pathogenesis of type 1 diabetes. however, the reduced responses to other -caas in young gad - tg mice demonstrate that gad65-reactive t - cells play an important role in activating or expanding early -cell autoreactivities. in contrast to another study of passive tolerance (15), we did not detect shifting of t - cell autoreactivity to cryptic determinants of gad65 in gad - tg mice. thus, the increased presentation of gad65 by gad - tg apcs did not alter the determinant recognition pattern of spontaneous t - cell responses to gad65 or the t - cell 's functional phenotype. despite the transgenic expression of gad65 by professional apcs to enforce passive tolerance to gad65, some cognate t - cells, presumably those with low avidity, escaped negative selection and were spontaneously activated before the mice were 8 weeks of age. another study showed that gad65 expression under the control of an mhci promoter was unable to induce tolerance to gad65 (13). young preautoimmune nod mice have a large pool of high - avidity gad65-reactive precursor t - cells (29). together, these observations indicate that gad65 has limited impact on t - cell selection during the development and maturation of nod mouse t - cells and that even when extraordinary efforts are taken to ectopically express gad65 in a manner expected to delete / anergize cognate t - cells in transgenic mice, it is difficult to establish complete tolerance to gad65 and prevent the early activation of remaining cognate t - cells. in nod mice, high - avidity gad65-reactive t - cells are spontaneously activated at the earliest stages of the autoimmune process (29). if gad65-specific t - cell autoimmunity is a minor component of early autoimmune response, the elimination or functional impairment of many gad65-reactive t - cells in gad - tg mice should have little impact on their development of t - cell autoreactivities to other -caas. in contrast to this notion, we observed that in the spleen and pln from 8-week - old gad - tg mice, spontaneous th1 responses were reduced not only to whole gad65 and peptides containing gad65 's dominant determinants but also to hspp277 and insulin b - chain. for example, splenic t - cell responses to hspp277 and insulin b - chain were 14 and 56%, respectively, of those in age - matched nod mice. it is likely that t - cell autoreactivities were also reduced to other -caas that we did not test. evidently, t - cell responses to gad65 provide support for the activation and expansion of t - cell autoreactivities to other -caas in young nod mice. in a more general sense, during the early stages of organ - specific autoimmune disease, nascent th1 autoreactivities to different target tissue antigens may be highly interdependent for support to further their activation and expansion. negative selection purges t - cells that interact too strongly with self - determinants, leaving t - cells that interact with self - antigens at below - activation thresholds (36,37). accordingly, young preautoimmune nod mice should have some t - cells that interact with cognate -caas near to their activation threshold (36,37). it is thought that a wave of -cell apoptosis at about 2 weeks of age leads to the increased presentation of -caas by apcs in the pln (38,39). this increased antigen presentation should theoretically result in the activation of t - cells that previously interacted with different -caas at just below their activation thresholds. this model predicts that there should be a simultaneous loss of self - tolerance to many different -caas. recently, an elegant study of insulin - tolerant transgenic nod mice found that these mice have little or no insulitis and do not develop type 1 diabetes, suggesting that insulin is the primary target autoantigen (40). an alternative explanation, consistent with the observations reported here, is that early t - cell autoreactivities are interdependent for the expansion of effector t - cells. without the usual support from insulin - reactive t - cells in the insulin - tolerant nod mice, other -caa reactive effector t - cells that were activated following -cell remodeling may have succumbed to activation - induced cell death or they were well controlled by tregs. indeed, t - cells from insulin - tolerant mice efficiently transfer type 1 diabetes to nod.scid mice, albeit more slowly, demonstrating that effector t - cells do arise in these mice (40). it remains an open question whether more extensive tolerance to gad65 would have prevented the expansion of autoimmune responses in gad - tg nod mice. contrasting with the diminished t - cell autoreactivities to -caas in young gad - tg mice, we observed supernormal autoreactivities to -caas in older gad - tg mice. although th1 responses to gad65 and its dominant peptides remained at a low level in older gad - tg mice, at 12 weeks of age splenic t - cell autoimmunity to hspp277 and insulin b - chain were 137 and 121%, respectively, and their pln responses were 131 and 202%, respectively, of those in their nod mouse littermates. a similar pattern was observed in 16-week - old gad - tg mice. the increased th1 autoimmunity to non - gad65 -caas indicates that these antigens are well presented by gad - tg apcs, despite their ectopic expression of gad65. gad65 contains many autoantigenic determinants (1,21), and a large pool of high - avidity gad65-reactive precursor t - cells are present in preautoimmune nod mice (29). early in the disease process, when activated autoreactive t - cells are infrequent and the local inflammation is at a low - level, competition for apcs and room for homeostatic proliferation should not be limiting factors. as the disease progresses, autoreactive t - cells become more frequent, and their functional development and activity require antigen presentation and costimulation, such that competition for apcs and space for t - cell expansion may become limiting factors. conceivably, the elimination / inactivation of many gad65-reactive t - cells in gad - tg mice removed many competitors for apcs and provided more room for the expansion of t - cells that recognize other -caas by homeostatic proliferation in the target tissue (41), particularly at late stages of the disease process. the greater opportunity for non gad65-reactive t - cells to interact with apcs and to expand may account for the development of supernormal t - cell responses to non - gad65 autoantigens in 12- and 16-week - old gad - tg nod mice. t - cell responses to islet lysate in gad - tg mice were reduced at 8 weeks of age, but at 12 and 16 weeks of age they increased to the same level as that in age - matched nod mice. we suspect that the hole left by eliminating gad65-reactive t - cells was filled - in by other autoreactive t - cells, such that there was an increase in the frequency of individual -caa specific t - cell responses without an overall increase in the number of islet lysate - reactive t - cells. the enhanced autoimmunity to non - gad65 autoantigens, together with the normal frequency of th1 responses to islet lysate in older gad - tg mice, may explain why gad - tg mice develop type 1 diabetes at a rate similar to that of nod mice. our observations suggest that during the autoimmune process, there are two phases of t - cell activation and expansion : an early phase in which t - cells recognizing different -caas are mutually dependent for activation and expansion, followed by a later phase in which an autoantigen - specific t - cell pool can expand autonomously. early in the autoimmune process, a few t - cells from different -caa reactive t - cell pools activate and collectively generate a weak proinflammatory environment that is barely sufficient to support further nave t - cell activation and activated t - cell expansion. elimination or functional impairment of one of the major autoantigen - specific pools during this early phase can significantly decrease inflammation in the local environment and curtail the activation and expansion of other autoreactive t - cells. with disease progression, some autoantigen - specific t - cell pools have expanded to the point that they can continue expansion autonomously via positive feedback mechanisms. the shift of autoantigen - specific effector t - cells from interdependence to autonomous expansion may be an important feature of the maturing autoimmune response. in the later autonomous phase, elimination / impairment of t - cells recognizing one autoantigen may have little beneficial effect and rather may promote the activation and expansion of other -caa reactive t - cell pools that have already reached the autonomous phase. we found that inducing passive tolerance to one autoantigen can lead subsequently to enhanced autoreactivities to other target tissue antigens. this suggests that therapeutic strategies based on inducing passive tolerance may not be very effective for t - cell mediated autoimmune diseases. the induction of long - lived regulatory responses (active tolerance) may be a better therapeutic strategy to control a diverse autoimmune response (rev. in 42). many different -caa based immunotherapies that induce regulatory responses can prevent type 1 diabetes when administered to young nod mice but lose efficacy when administered later in the disease process (4245). their efficacy in young nod mice may, in large part, be due to reducing the local inflammation on which -caa reactive t - cells depend for activation and expansion during their mutual dependence phase. in older nod mice, the ability of some autoantigen - specific t - cell pools to autonomously expand, together with increased proinflammatory bystander effects, makes it more difficult for therapy - induced regulatory t - cells to inhibit disease progression. moreover, antigen - based therapies prime fewer regulatory responses in older nod mice because many cognate t - cells have already been activated and committed to the autoimmune response, reducing the pool of nave t - cells available for priming (46). these coinciding effects may help explain the attenuated efficacy of antigen - based therapeutics as nod mice mature. our studies underscore the dynamic nature of autoreactive t - cell responses and the need to better understand the immunological impact of antigen - based therapies designed to induce passive or active tolerance. modulating a single autoreactive t - cell pool may have complex and unexpected effects on other autoreactive t - cell responses. | objectiveto study how tolerance to gad65 affects the development of autoimmunity to other -cell autoantigens (-caas) in gad65-transgenic (gad - tg) nod mice.research design and methodswe used elispot to characterize the frequency and functional phenotype of t - cell responses to gad65 and other -caas at different ages in gad - tg mice and their nod mouse littermates.resultsin young gad - tg mice, th1 responses to gad65 's dominant determinants were 1318% of those in young nod mice. this coincided with a great reduction in th1 responses to other -caas. evidently, gad65-reactive t - cells are important for activating and/or expanding early autoreactivities in nod mice. as gad - tg mice aged, their t - cell responses to gad65 remained low, but they developed supernormal splenic and pancreatic lymph node t - cell autoimmunity to other -caas. apparently, the elimination / impairment of many gad65-reactive t - cells allowed other -caa reactive t - cells to eventually expand to a greater extent, perhaps by reducing competition for antigen - presenting cells, or homeostatic proliferation in the target tissue, which may explain the gad - tg mouse 's usual disease incidence.conclusionstransgenically induced reduction of gad65 autoreactivity curtailed the development of early t - cell responses to other -caas. however, later in life, -caa reactive t - cells expanded to supernormal levels. these data suggest that early -cell autoreactivities are mutually dependent for support to activate and expand, while later in the disease process, autoantigen - specific t - cell pools can expand autonomously. these findings have implications for understanding type 1 diabetes immunopathogenesis and for designing antigen - based immunotherapeutics. |
untreated odontogenic infections can advance to osteomyelitis, cellulitis, myofascial space abscess, lymphadenitis, bacteremia, or sepsis, all of which can be extremely dangerous. brain abscesses, which are rare, are also a potential type of infection that could arise. these are suppurative infections of the brain parenchyma that are surrounded by a vascularized capsule. in the united states, there are only 1,500 to 2,500 brain abscess cases each year1. bacterial brain abscesses have three main etiologies. the most common cause is contiguous spread of infection from the oropharynx, middle ear, and paranasal sinuses2. the aim of this report is to present a rare case of a brain abscess due to odontogenic infection in a middle - aged woman. a 53-year - old female visited the department of oral and maxillofacial surgery at the sun dental hospital (daejeon, korea) in september 2013 with trismus being her chief complaint. the patient had been receiving treatment for headaches and trismus at a local medical hospital and dental clinic for two weeks but the symptoms did not subside and the etiology was unclear. routine clinical and radiologic exams showed localized chronic periodontitis of the maxillary right posterior region, but no other possible causes of the patient 's symptoms (e.g., fascial space abscess) were found.(figs. 1, 2) no systemic conditions that could have interfered with the patient 's immune system were found. a pterygomandibular space abscess was first suspected to be the cause of trismus, but palpation and an aspiration exam yielded negative results. meanwhile, laboratory blood tests revealed signs of an on - going infection. these results showed a white blood cell count of 12,900/mm with a differential count of 76.9% segmented cells and 16.5% lymphocytes. the erythrocyte sedimentation rate was 114 mm / hr and c - reactive protein level was 11.02 mg / dl. the patient 's body temperature was 36.9. she also showed signs of myalgia, slightly altered orientation, and speech difficulty. after her admission to the hospital, additional radiographs were taken. on day one at the hospital, the patient had a 38.9 body temperature, which then rose to 39.3. she complained of a headache and soon became drowsy. empirical antibiotics, such as augmentin, isepamicin, and metronidazole, were administered five days prior to her operation. during imaging analyses, a 1.51.5 cm - sized perforation of the right sphenoid bone was detected (fig. 3) and on magnetic resonance imaging (mri) t2, a 1.31.8 cm - sized capsulated regular mass was observed in the right temporal lobe along with irregular edema.(fig. 4) after consulting with neurosurgery specialists, the patient was diagnosed with a brain abscess of dental origin. the patient then underwent abscess drainage through a craniotomy procedure, which involved decompressive craniotomy and aspiration without resection of the capsule while the patient was under general anesthesia. approximately 8 ml of yellowish - brown pus was aspirated from the legion (fig. 5) and the capsule of the abscess was not removed because it had adhered to the brain parenchyma. the patient was put on postoperative intravenous antibiotic therapy, including ceftriaxone, hanomycin (sam jin pharm., one week after undergoing decompressive craniotomy and aspiration, the patient 's headache disappeared and her maximal mouth opening increased to about from 15 mm to 30 mm. the upper right second molar, which was suspected to be the source of the infection, was extracted while the patient was under local anesthesia.(fig. the patient remained under the care of an oral surgeon and a neurosurgeon and she recovered fully. table 2 shows the patient 's lab results and body temperatures at different treatment stages. by seven months post - surgery, there had been no recurrence of the infection, as determined by computed tomography (ct) and mri during follow - up appointments.(fig. it can have as its etiology a metastasis of chronic suppurative disease or congenital cardiomyopathy, or can arise after trauma like open - head injuries or after neurosurgical procedures. sinusitis, otitis, and untreated odontogenic infections can also be a cause of brain abscess7. corson.8 reported that cerebral abscesses, albeit rarely, can result from dental or maxillofacial infections. a diagnosis of brain abscess is considered definite if bacterial organisms were isolated from abscess pus or cerfebral spinal fluid cultures. in this case, the ct scan showed findings characteristic of brain abscess, including the classical clinical manifestations of headache, fever, localized neurological signs, or disturbance of consciousness. in other patients, confirmation of abscess has come about upon the disappearance of ct abnormalities after antibiotic treatment. development and advancement of antibiotics, bacteriological culture and identification techniques, computed tomography, and magnetic resonance imaging have changed the prognosis dramatically1,9,10, which, in turn, has resulted in the mortality rate being reduced from 40%-60% in the pre - ct era to 0%-10% currently1. the causative pathogens of brain abscesses vary with underlying medical or surgical conditions and the mode of infection11,12. lu.12 reported 19 out of 123 patients with brain abscesses were culture - negative. between 24%-40% of all intracerebral abscesses produce negative culture results because the patient has already received antimicrobial therapy12, which is the reason that we suspect there was no bacterial growth in this case. there have been a few articles dealing with brain abscesses that have suspected odontogenic origin. a pubmed search using the key words " brain abscess, " " odontogenic, " and " dental " yielded twenty - two articles, all of which were case reports. however, none of these reports described the relationship between brain abscess and dental infection because they lacked evidence to do so. in the case reported here, there was a clear progression route from infection in the right maxillary second molar to the right temporal lobe through the perforated sphenoid bone. upon extracting the right maxillary second molar, severe palatal root resorption was observed. in 2000, de louvois.13 argued for a more thoughtful use of antibiotics for treating brain abscesses, emphasizing the ability of antibiotics to penetrate the blood - brain barrier. sjlin.14 used third - generation cephalosporins, such as cefotaxime, ceftriaxone, and ceftazidime, as well as metronidazole, to treat patients with odontogenic intracranial infections. they recommended a combination of ampicillin, metronidazole, and either ceftazidime or gentamicin, for treating otogenic abscesses. gorgan.15 reported a general morbidity of 26.19% and mortality remained stable at 7.14% among a total of 84 patients over 12 years, from 2000 to 2011. half of the patients in this series were diagnosed inaccurately at the initial stage, and it took an average of 7.2 days until the patients received the accurate diagnosis of brain abscess. bibliographically, the average time between the onset of the symptoms and confirmed diagnoses was 9.6 days16. in the case successful treatment of brain abscesses requires early diagnosis, timely surgical intervention, and continuous high - dose antibiotic therapy. symptoms of brain abscess include headache, changes in mental state, nausea, vomiting, seizures, hemiplegia, speech disturbance, visual disturbance, and others. therefore, in examining patients with infections in the head and neck region, if they display any of the above symptoms, brain abscess should be included in the differential diagnosis list. an immediate medical consultation to the neurosurgery department must follow when brain abscess is suspected. | in this report, we describe a case of brain abscess due to odontogenic infection. a 53-year - old female who had been suffering from headache and trismus for two weeks visited the department of oral and maxillofacial surgery at the sun dental hospital (daejeon, korea). even after several routine tests, we still could not make a diagnosis. however, after the combined multidisciplinary efforts of oral surgeons and neurosurgeons, the patient was treated for odontogenic infection and made an uneventful recovery. therefore, patients with infections in the head and neck region showing symptoms such as headache, changes in mental state, nausea, vomiting, seizures, hemiplegia, speech disturbance, and visual disturbance, a brain abscess should be included in the list of differential diagnoses. |
one of the important promises of nanotechnology is the development of techniques and tools for cancer diagnosis using safe, noninvasive, low - cost means with high resolution and sensitivity. existing clinical imaging modalities, such as computed tomography, magnetic resonance imaging (mri), positron emission tomography, and ultrasound, differ from one another in terms of detection sensitivity, spatialtemporal resolution, signal - to - noise ratio, quantitative accuracy, and long - term safety.(1),(2) none of these methods are capable of providing complete structural and functional information independently.(3) hence, it is often desirable to employ information from complimentary imaging modalities to enhance prognosis and enable early and accurate detection of tumors. the need for complimentary diagnostic information has led to the emergence of multimodal contrast agents that are capable of generating contrast by different modalities, simultaneously. mri, a common clinical imaging modality, has the capability of constructing three - dimensional (3d) images of biological structures providing high anatomical details. high dosages of commercial gd - based mr contrast agents are commonly used to improve image resolution. however, these contrast agents, by themselves, are not sensitive enough to obtain images that can be resolved at the single - cell level. single - cell mri capability will allow for early disease diagnosis, stem cell tracking, gene and drug delivery, etc. therefore, the development of high - resolution image contrast agents such as nanoparticle - based mri contrast agents has a great demand. photoacoustic tomography (pat, also known as laser optoacoustic or thermoacoustic imaging) is an emerging noninvasive, nonionizing, deeply penetrating imaging modality that combines the advantages of the sensitivity of optical methods with the resolution of diffraction - limited ultrasound. in pat, a nonionizing short - pulsed optical laser is used as an excitation source to generate an acoustic signal resulting from thermoelastic expansion of the absorbent which is then detected and used to recover the geometry of the object. pat has been used to image tumors, blood vessels,(9) hemoglobin oxygenation,(10) tumor angiogenesis(11) in the absence and presence of contrast agents. it would be advantageous to obtain simultaneous structural and functional information with high resolution using a multimodal image contrast agent for noninvasive imaging by both pat and mri. in this paper we report a novel multimodal nanoparticle that provides the first example of a single - nanoparticle contrast agent for noninvasive imaging by both pat and mri. the use of mri, a well - established imaging method, in parallel with pat (made possible through the use of these nanoparticles) is expected to enable rapid enhancement and further development of improved computational algorithms for pat image construction enhancing the breath and capabilities of the method. pat may potentially prove useful for patients with cardiac pacemakers, certain metallic implants, or metallic debris (e.g., shrapnel, iron filings) in their body that are precluded from undergoing mri scans due to strong magnetic fields. although pat currently does not provide the magnitude of anatomical information afforded by mri, it can provide 3d deep tissue imagery that is comparable to mri particularly in the presence of contrast agents. mripat bimodal contrast agents may also be used for clinical prescreening purposes to lower the burden on existing mri facilities and provide a low - cost, nonionizing method for the analysis of soft tissue. multimodal mripat nanoparticles are also envisaged to be potentially useful for diagnostic imaging and therapy of cancer. because the generation of acoustic signal is due to the thermoelastic expansion of the pat contrast agents, it is possible to elevate the temperature of the target tissue by increasing the intensity of the incident laser beam, causing significant damage to tumor tissue. thus, the development of safer, nonionizing diagnostic methods would enable implementation of advanced bioimaging solutions for larger spectrum of patients that can be applied in the field, in common clinics, as well as in major hospitals and medical institutions. tetraethylorthosilicate (teos), triton x-100 (tx-100), n - hexanol, 3-(aminopropyl)triethoxysilane (apts), and cyclohexane were purchased from aldrich chemical co. inc. n-(trimethoxysilyl - propyl)ethyldiaminetriacetic acid trisodium salt (tspete) (45% wt % solution in water) was purchased from gelest co., gold chloride, gadolinium acetate, and hydrazine hydrate were obtained from acros organics, and ammonium hydroxide (nh4oh, 2830 wt %) was obtained from the fisher scientific co. all other chemicals were of analytical reagent grade. deionized (di) water (nanopure, barnstead) was used for the preparation of all solutions. the complete synthesis of the multimodal nanoparticles was done in one pot using reverse micelles. the water - in - oil (w / o) microemulsion was prepared by mixing tx-100 cyclohexane, n - hexanol (1:4.2:1 v / v), and appropriate water. n - hexanol was used as a cosurfactant to the nonionic surfactant, tx-100. an amount of 0.050 ml of teos was added in the beginning to the microemulsion and allowed to equilibrate for 30 min. the hydrolysis and polymerization of teos was then initiated by adding 0.050.200 ml of nh4oh. the overall w0 (water to surfactant molar ratio) after addition of nh4oh was 10. after allowing silica polymerization reaction to go for 24 h, the surface of the silica nanoparticle was modified with the addition of 0.025 ml of tspete and 0.050 ml of teos. this was followed by the addition of 0.10 ml of 0.1 m gd(iii) acetate solution and stirring for another 4 h. this was followed by addition of 0.5 ml of 0.25 m haucl4, prepared in degassed water, and 1.1 m solution of reducing agent (hydrazine hydrate). the solution was allowed to stir for 12 h. the progress of the reaction at each step was monitored by uvvis absorption spectroscopy. the gd - doped gss nanoparticles were then isolated from the microemulsion by adding 5 ml of 200 proof ethanol. this led to the complete breakdown of reverse micelles with the formation of two immiscible layers of aqueous ethanol and cyclohexane. the particles were washed three times with ethanol and five times with water in order to completely remove surfactant molecules. each centrifugation step, during washing was followed by vortexing and sonication to redisperse the pelleted particles. after complete removal of surfactant the particles were redispersed in nanopure water to obtain a concentration of ca. the particle size and distribution were measured by dynamic light scattering (dls) using a microtrac nanotrac and cps disk centrifuge. the size and morphology of the particles were determined by transmission electron microscopy (tem). tem and energy - dispersive x - ray spectroscopy (eds) spectra of the particles were done using jeol 2010f transmission electron microscope. inductively coupled plasma (icp) measurements were performed using a perkin - elmer plasma 3200 system equipped with two monochromators covering the spectral range of 165785 nm with a grated ruling of 3600 lines / mm. ] au and gd were completely solubilized in the aqua regia, whereas the silica matrix was settled at the bottom of the container as a white powder. the particles were washed three times with aqua regia solution and finally twice with nanopure water. the filtrate and the particles were all collected together and boiled to concentrate the volume to 15.0 ml. after instrument calibration was performed for au and gd estimation, the filtrate was analyzed by icp for quantitative estimation of gd and au. phantom preparation for mr relaxivity measurements was done by serially diluting a 10 mg / ml stock solution of gd - doped gss nanoparticles with ddh2o and mixing with a 1% agarose solution (ultra - pure agarose, invitrogen, carlsbad, ca) yielding a final concentration of 0.5% agarose. the resulting nanoparticle concentrations of 5, 2.5, 1.25, 0.625, and 0.3125 mg / ml were then injected into 100 l capillary tubes (curtin - matheson scientific, broomall, pa) and allowed to solidify on ice, thereby eliminating sedimentation during relaxivity measurements. the comparison of mr response between gd - doped gss nanoparticles and silica nanoparticles (without any gold or gd) was performed similarly by diluting 10 mg / ml nanoparticles in 1% agarose solution (supporting information). control phantoms containing just 0.5% and 1% agarose were simultaneously imaged to determine effect of agarose on relaxation times. right before imaging, all samples were placed together inside a water - filled facs tube (bd falcon, franklin lakes, nj) to avoid susceptibility artifacts from the surrounding air. all relaxivity data were analyzed using paravision software (pv3.02 ; bruker medical). for measuring t1 relaxation times, axial spinecho (se) scan sequences were obtained with te = 4.5 ms, matrix size = 128 128, fov = 2.8 2.8 cm, spectral width = 180 khz, one average, 1 mm slice thickness, and varying tr values of 11, 6, 3, 1.5, 0.75, 0.5, 0.25, 0.125, 0.075, 0.05, 0.025, and 0.015 s. for t2 relaxation measurements, axial t2-weighted single - slice multiecho images were obtained with tr = 11 s, te = 5 ms te = 5 ms (60 echoes), matrix size = 128 128, fov = 2.8 2.8 cm, spectral width = 100 khz, two signal averages, and a 1 mm slice thickness. t1 and t2 maps were calculated assuming a monoexponential signal decay and by using a nonlinear function, least - squares curve fitting on the relationship between changes in mean signal intensity within a region of interest (roi) to tr and te. t1 and t2 relaxation times(s) for the gd - doped gss nanoparticles in 0.5% agarose were then derived by roi measurements of the test samples converted into r1 and r2 relaxation rates (1/t1,2 (s)). finally, r1,2 values were plotted against the concentration of gd on the nanoparticle and r1 and r2 (mm s) relaxivities were obtained as the slope of the resulting linear plot. t2 trs were kept constant at 500 ms with varying tes of 4, 8, 12, 16, 20, 40, 60, and 100 ms, fov = 2.8 2.8 cm, matrix size = 256 256, two signal averages, spectral width = 60 khz, and 1 mm slice thickness. image j software (nih) with an mr analysis calculator plug - in was used to quantify t2 values by stacking the individual flash sequences with varying tes and creating a t2 map. rois for each cell sample were then drawn to contain the entire cross section of each of the samples, and values were then plotted as r2 (or the inverse of t2 (1/t2, (s))), against the concentration of gd in the sample (excel, microsoft inc.). r2 relaxivity (mm s) was later obtained as the slope of the resulting linear plot. a mechanical scanning photoacoustic system with single acoustic transducer to collect the acoustic signals was utilized. a pulsed nd : yag laser (altos, bozeman, mt) working at 532 nm with 4 ns pulse duration, 10 hz repetition rate and 360 mj maximum pulse power acted as light source. an immersion acoustic transducer with 1 mhz nominal frequency (valpey fisher, hopkinton, ma) was driven by a motorized rotator to receive acoustic signals over 360 for phantoms at an interval of 3, and thus a total of 120 measurements were performed for one planar scanning. the scanning plane could be adjusted along the z - axis by mounting the rotator and the transducer on a platform driven by a linear stage. the acoustic transducer was immersed into the water tank while the phantom was placed at the center of the tank where it was illuminated by the laser. the complex wave field signal was amplified by a pulser / receiver (ge panametrics, waltham, ma) and then acquired by a high - speed pci data acquisition board. pat images were reconstructed by our reconstruction algorithm that is based on the finite element solution to the photoacoustic wave equation in the frequency domain, which can provide stable inverse solutions.(18) phantoms for imaging were constructed using intralipid, india ink, distilled water, and 2% agar powder as described previously.(19) the diameters of all phantoms used in this study were 25 mm. the absorption and reduced scattering coefficients (optical properties) of these phantoms were 0.007 and 0.5 mm, respectively. mouse monocyte / macrophage j774 cells were defrosted, resuspended in dulbecco s modified eagle s medium (dmem) (gibco, grand island, ny) supplemented with 10% fetal bovine serum (summit biotechnology, ft. collins, co), 1% glutamax (gibco), 1% penicillin / streptomycin (gibco), and incubated at a density of 5 10 cells / ml in 100 mm culture dishes at 37 c and 5% co2. media was replaced 24 h after plating, and the cells were allowed to attach and grow to confluency (usually within 23 days). old media was replaced with fresh before the cells were harvested and washed twice by spinning them down at 1100 rpm for 5 min using a sorvall rt7 plus ultracentrifuge and resuspending in fresh dmem complete media. cells were subsequently replated at a density of 2 10 and again allowed to attach and grow to confluency. cells were passaged for 34 times before the start of the labeling experiment. during labeling, 1 10 freshly split j774 cells / ml dmem complete were incubated overnight with 100 g / ml of gd - doped gss nanoparticles in a six - well tissue culture dish. the next day label - containing media was aspirated off and replaced by fresh media before labeled and unlabeled control cells were scraped up, washed twice in ice - cold dulbecco s phosphate - buffered saline (dpbs) (gibco, grand island, ny), counted, and resuspended at a density of 3.33 10 cells / ml each in dpbs (2 10 cells in 60 l dpbs). cells were kept on ice until the time of imaging when 20 l of cell suspension was then injected in the phantom. the sample phantom containing gss - labeled j774 and control cells was placed inside a solenoid coil and imaged at 4.7 t magnetic field strength. t1- and t2-weighted se scan sequences were used to detect gd on the nanoparticles inside the cells. for generating t1-weighted images a multislice multiecho (msme) pulse sequence was used with tr = 500 ms, te = 5 ms, matrix size = 256 256, fov = 3 3 cm, spectral width = 100 khz, two signal averages, and a 1 mm slice thickness. t2-weighted images was acquired either by using a msme pulse sequence with tr = 500 ms, te = 100 ms, matrix size = 256 256, fov = 3 3 cm, spectral width = 100 khz, two signal averages, and a 1 mm slice thickness or by using a rapid acquisition with relaxation enhancement (rare) pulse sequence with tr = 1000 ms, te = 12 ms, matrix size = 256 256, fov = 3 3 cm, spectral width = 60 khz, four signal averages, rare factor = 8, and a 1 mm slice thickness. existing contrast agents for pat include near - ir absorbing dyes and gold - based nanomaterials, which have been demonstrated for various therapeutic and imaging applications. although the possibility of using gold nanoshells as exogenous pat contrast agent has been described,(27) only a few experimental reports exist in the literature.(14) similarly, the application of molecular dyes in pat has been limited due to their poor in vivo stability and rapid clearance from the biological systems.(28) although gold nanoshells exhibit the desired optical and photothermal properties for pat, the need for a continuous shell of up to 20 nm in thickness (resulting in an overall particle size of 120150 nm) limits their capacity to internally integrate mri contrast through the restriction of water exchange. moreover, their larger size (> 120 nm) could limit certain bioimaging applications such as tracking stem cells, viruses, etc., where size tunability, in particular, smaller particle size, is preferred. to overcome the size restrictions of existing gold nanoshell particles as well as introduce the property of being multimodal contrast agents, we have developed a goldsilica hybrid material termed gold - speckled silica (gss) nanoparticles. these mripat - active multimodal nanoparticles have a surface layer composed of discontinuous, irregular gold nanodomains of varying crystallinity that are incorporated within the pores and on the exterior of the supporting silica matrix. the multitude of dielectricmetal interfaces created by this method gives rise to unique photothermal properties that enable the use of these materials as contrast agents in pat. these multimodal gss nanoparticles possess high mri relaxivity and at the same time produce a strong pat contrast. the complete synthesis of the multimodal gss nanoparticles has been carried out in one pot using the nonionic w / o microemulsion method. briefly, gd - doped silica nanoparticles are first formed by cocondensation of teos and a silane reagent that strongly chelates polyvalent metal ions (tspete) in the water core of the tx-100/n - hexanol / water w / o microemulsion. incorporation of chloroauric acid followed by its reduction was the carried out within the surface layer of the silica nanoparticles. by manipulating w0 of the microemulsions and the reactant concentrations, we were able to tune gd - doped gss nanoparticle size from less than 50 to 200 nm. parts a and b of figure 1 show representative tem micrographs for two different samples prepared at w0 10 and 14, depicting mean particle size of 100 (10) and 55 (5) nm, respectively. gss nanoparticles up to 200 nm and larger were synthesized at w0 5 (supporting information) using the same microemulsion system. (a) representative tem picture of gd - doped gss nanoparticles, with an average size of 100 nm and (b) gd - doped gss particles with an average size of 50 nm. (c) high - resolution tem picture of the nanoparticle showing the presence of electron - dense gold on the silica nanoparticle and (d) dark - field tem picture showing the contrast from the presence of the electron - dense species. a key difference between the current particles and those previously described in the literature lies in the nature of the gold nanoparticle generation and deposition on and in the silica matrix. in a traditional synthesis route (seed - mediated synthesis), 12 nm uniform gold nanoparticles are first deposited on the silica surface as small clusters. in the following step, the shell thickness of the gold nanoshells can vary between 120 nm. unlike the traditional approach of depositing gold nanoparticles onto silica nanoparticles, we incubated gd - doped silica nanoparticle within the aqueous core of the microemulsion with chloroauric acid, allowing gold ions to permeate further into the mesoporous silica matrix. upon reduction a unique gold - speckled surface results due to the deposition of the gold nanodomains. via this method discontinuous, randomly deposited, sometimes templated, and often irregular gold nanoclusters are formed within and on the surface of the silica core. high - resolution tem (hrtem) micrographs of 100 nm gd - doped gss nanoparticles (prepared at w0 = 10) demonstrate speckled surface deposits of gold, as seen in areas of darker contrast on the silica surface (figure 1c) and as areas of lighter contrast in the dark - field tem picture (figure 1d). note that gd doping also contributes to the background as a darker and lighter haze in figure 1, parts c and d, respectively. the hrtem micrograph (figure 2) shows scattered deposition of gold nanoparticles ranging from less than 1 to 5 nm, with varying crystallinity, on the silica surface. these random and irregular clustered deposits, which include templated deposits within the mesopores, make this class of particles distinct and provide for their unique optical properties such as efficient photothermal properties. since these particles were also doped with gd ions a paramagnetic species that affects the longitudinal relaxation rate of water they exhibited mri contrast. high - resolution tem picture of the nanoparticle showing the lattice planes of gold nanoparticles as deposited on the silica nanoparticle. the elemental composition of the gd - doped gss nanoparticles particles was determined using eds and icp techniques. a representative line scan (figure 3a) and composite eds spectrum (figure 3b) showed the spectral counts corresponding to si, o, au, gd, and the overall spectrum for the nanoparticle, respectively. the elemental composition as determined by icp gave average number of atoms of au and gd to be 426 200 and 34 000 per nanoparticle, respectively. theoretical calculations showed that 72 times more number of gold atoms would be present in a single gold nanoparticle of similar dimension. to our knowledge, this is the first report of one - pot synthesis of gd - doped gss nanoparticulate contrast agents as well as the first example of a multimodal contrast agent for mri and pat. the evaluation of the mri and pat bifunctional properties of these nanoparticulates has been demonstrated using agar gel phantoms as described in the following sections. (a) line scan of gd - doped gss nanoparticle showing the spectral emission from the constituent elements. (b) eds spectrum of the multimodal nanoparticles showing the presence of silicon (si), oxygen (o), gold (au), and gadolinium (gd). the gd - doped gss nanoparticles were shown to generate mr contrast on both t1 and t2 proton relaxation time weighted sequences as depicted in figure 4, parts a and b. quantitatively, mr contrast is evaluated by estimating the relaxivity of the nanoparticle. the relaxivity (ri, i = 1, 2) is defined as the gradient of the linear plot of relaxation rates (1/ti, i = 1, 2) versus gd concentration [gd],(35) i.e., 1/ti = 1/to + ri[gd ], where ti is the relaxation time for a contrast agent solution concentration [gd ] and to is the relaxation time in the absence of a contrast agent. from the data in figure 4ce, the relaxivities r1, r2, and r2 are determined to be 13, 110, and 173 mm s, respectively. when compared with commercially available contrast agents, gdgss exhibit much higher relaxivity values under the same magnetic strength of 4.7 t.(36) in mri, it is well - established that the gd - generated mr contrast relies on the relaxation process of the water molecules in association with the gd ion and those exchanged in the surrounding environment. for an efficient relaxation process, rapid water exchange between bound (or inner coordination water) with the bulk water and slow tumbling play an important role.(37) the gd - doped gss nanoparticles address both these factors. first, the presence of the discontinuous gss surface allows sufficient bulk water exchange with the gd ions enabling mr tracking ability. it should be noted that a continuous gold shell over the silica core could limit the extent of water exchange inhibiting t1 contrast. second, tumbling rate another important factor for producing an effective mri contrast is also reduced in the gd - doped gss particles through the rigid binding of gd to the nanoparticle surface. because the tumbling rates are mass - dependent, nanoparticles are much slower than free gd chelates and thus produce an enhanced relaxation. one of the major limitations of current molecular chelates used as mr contrast agent is their low sensitivity ; this requires the use of higher dosages and results in poor targetability.(38) both these concerns are also addressed in the present construct. approximately, 34 000 ions of gd are captured per nanoparticle with an average size of 100 nm, which is higher than the number of gd ions previously reported in other nanoparticles such as synthetic polymers (670 ions) and in dendrimers (between 5 and 1331 ions, strongly dependent on particle size(39)) and comparable to perfluorocarbon nanoparticles (90 000 gd ions in 250 nm diameter particle(40)). magnetic resonance data and pat contrast from gd - doped gss nanoparticle. (a) t1-weighted (repetition time (tr) = 11 000 ms, echo time (te) = 4.2 ms) and (b) t2 tr = 500 ms, te = 40 ms images of serial dilutions of gd - doped gss nanoparticle : (a) 0.24, (b) 0.12, (c) 0.06, (d) 0.03, and (e) 0.015 mm of gd in 0.5% agarose and (f) 0.5% agarose (as control). linear plots of gd concentration vs (c) 1/t1, (d) 1/t2, and (e) 1/t2, respectively, to obtain ionic relaxivities, r1, r2, and r2, respectively, of gd - doped gss nanoparticle. (f) comparison of pat contrast from gold and gss nanoparticles of similar size and concentration (8 l of 10 mg / ml) in a tissue - like phantom with background : absorption coefficient a = 0.007 mm and reduced scattering coefficient, s = 0.5 mm. a stronger photo - acoustic signal is obtained from gss nanoparticles as compared to gold nanoparticles. the ability of gdgss nanoparticles to generate photoacoustic contrast was confirmed by placing the particles in an agar phantom containing india ink and intralipid to simulate tissue - like absorption and scattering. figure 4f shows the comparison of pat contrast from gss nanoparticles and compares it to that of similar size and concentration of gold nanoparticles. the dark red region in the area of the nanoparticles, with respect to the blue background, demonstrates that a strong pat contrast is observed from the particles. as shown in figure 4f the gss nanoparticles generated a stronger photoacoustic signal when compared to the gold nanoparticles. the stronger pat contrast from the gss nanoparticles, in spite of the presence of 72-fold less gold atoms, demonstrates them as a better pat contrast agent. control experiments were also performed using silica nanoparticles (without gold or gd) which illustrated that the bare silica nanoparticles do not have a significant pat contrast (supporting information). because the pat originates from the optical absorption of the illuminating laser wavelength, the gss particles also hold therapeutic potential for the thermal ablation of tumors. hence, the particles described here hold both multimodal imaging as well as therapeutic capabilities. to evaluate the bimodal character of the gss nanoparticles, simultaneous mr and photoacoustic evaluation was carried out. to achieve this, the phantom was imaged for pat and mr in succession, and the results are shown in figure 5. an increase in the mr and pat signal intensity is observed with increasing particulate amounts. (a) the pat and (b) mri (t1) contrast from the same phantom, using 1, 3, and 5 l (particle concentration, 10 mg / ml) of gd - doped gss using sample in tissue - like phantom with background absorption coefficient a = 0.007 mm and scattering coefficient, s = 0.5 mm, demonstrating the multimodal nature of the nanoparticles. in vitro studies have also been carried out with the gss nanoparticles to assess the functional ability of the particles in the cellular environment. the uptake of the gss nanoparticles by j774 macrophages was carried out as explained in the. the cells were then placed in tissue - like phantom and imaged by pat and mri in succession. figure 6 shows the phantom design with the sample placement and the mr and pat images obtained with the same phantom. it is observed that the cells labeled with the gss nanoparticles produce a strong pat contrast as compared to the background. the mr image of the same phantom shows the ability to generate the t1 and t2 contrast. the in vitro experiments demonstrated the capability of the gss nanoparticles to generate an efficient pat and mr contrast in living cells, showing potential use of gss nanoparticles as in vivo cell tracker. panel i shows the position of j 774 macrophage cells labeled with gss nanoparticles marked as a, and unlabeled cells b, in the tissue - like phantom. panel ii shows the pat image, panel iii is the t1-weighted spinecho image with tr = 500 ms, te = 6 ms, and panel iv is the t2-weighted spinecho image with tr = 500 ms, te = 100 ms. in summary, we have described the synthesis and systematic characterization of new mri- and pat - active multimodal nanoparticle - based contrast agents. the nanoparticles were prepared using a w / o microemulsion method where the nanoparticle size was tuned by varying microemulsion parameters such as w0 value and reactant concentration. the composite nanoparticles are composed of a silica core containing chelated gd moieties, partially covered with randomly deposited irregular gold speckles, or nanoclusters. the speckled surface permits efficient water exchange between the gd in the nanoparticle and the bulk water, resulting in an efficient mr contrast. these multimodal nanoparticles have the potential to be used as diagnostic as well as therapeutic agents. | in this report the synthesis, characterization, and functional evaluation of a multimodal nanoparticulate contrast agent for noninvasive imaging through both magnetic resonance imaging (mri) and photoacoustic tomography (pat) is presented. the nanoparticles described herein enable high resolution and highly sensitive three - dimensional diagnostic imaging through the synergistic coupling of mri and pat capabilities. gadolinium (gd)-doped gold - speckled silica (gss) nanoparticles, ranging from 50 to 200 nm, have been prepared in a simple one - pot synthesis using nonionic microemulsions. the photoacoustic signal is generated from a nonuniform, discontinuous gold nanodomains speckled across the silica surface, whereas the mr contrast is provided through gd incorporated in the silica matrix. the presence of a discontinuous speckled surface, as opposed to a continuous gold shell, allows sufficient bulk water exchange with the gd ions to generate a strong mr contrast. the dual imaging capabilities of the particles have been demonstrated through in silicio and in vitro methods. the described particles also have the capacity for therapeutic applications including the thermal ablation of tumors through the absorption of irradiated light. |
despite major advances in pancreatic surgery, pancreatic fistula (pf) continues to be a common complication after pancreaticoduodenectomy (pd) occurring in 914% of patients even at high volume centers [110 ]. classical risk factors associated with pf have been described in the literature and include the following : patient demographics, pancreatic gland texture, pancreatic duct size, pathology of periampullary lesion, anastomotic technique, and surgeon volume [1120 ]. this complication with pd continues to occur despite an acknowledged improvement in other types of postoperative complications and declining mortality rates in most large surgical series. as most surgeons realize, the technical challenges of sewing the pancreas to the intestinal tract are formidable. despite these difficulties, if substantial progress in reducing the rate of pf is to be made, improved understanding of the risk factors which predispose to fistula formation seems essential. identifying which glands in which patients are at high risk for a leak can trigger modifications in surgical technique, drainage, and postoperative care to minimize fistula formation. in this study we asked the following questions : first, what preoperative and perioperative factors might predict pf following pancreaticoduodenectomy ? second, what is the effect of pf on outcomes following pancreaticoduodenectomy ? to answer these questions, we analyzed our experience with pd at a high - volume pancreatic referral center and then examined the effect of these variables on the incidence of pf and the clinical outcomes in this group of patients. this is a retrospective review of a case series of consecutive patients who underwent pancreaticoduodenectomy for a broad range of periampullary and pancreatic pathologies between january 1980 and june 2002 at indiana university medical center, a tertiary care academic training hospital in indianapolis, indiana. only patients who had pancreaticoduodenectomy with a remnant, viable pancreatic tail were included for analysis. patients who underwent total pancreatectomy due to positive resection margins or those who had undergone previous distal pancreatic resections prior to their pancreaticoduodenectomy were excluded from this study. pancreatic fistula (pf) was defined during the broad range of years in this experience by several definitions. from 1980 to 1985, a pf was defined as > 10 ml of amylase - rich fluid per day from a surgically placed drain or through a cutaneous site (around a penrose drain) after postoperative day 8 and lasting for at least 8 days. from 19852002 our definition was > 50 ml / day of amylase rich fluid after postoperative day 11 and lasting for at least 11 days. since 2005 at our institution, we have used the international study group for pancreatic fistula (isgpf) guidelines defining pancreatic fistula as any measurable volume of fluid on or after postoperative day 3 with amylase content greater than 3 times the serum amylase activity (21). based on a careful review of the patients medical records during their hospital treatment and postoperative clinical follow - up, pancreatic fistula grades a, b, or c were assigned to each fistula identified as defined in the isgpf guidelines (see table 1). data were collected and reported in strict compliance with patient confidentiality guidelines put forth by the indiana university - purdue university indianapolis institutional review board. for preoperative variables twelve patient symptoms, physical signs, and associated conditions were included in the database including the following : abdominal pain, back pain, nausea / vomiting, diarrhea, abdominal tenderness, jaundice, diabetes, pancreatitis, abdominal mass, organomegaly, hemepositive stools, and weight loss. the diagnosis of jaundice was based on the presence of scleral icterus on physical examination. the presence of new onset diabetes mellitus was defined as the existence of glucose intolerance necessitating diet modification, oral hyperglycemic drug, or insulin supplementation within two years of the diagnosis of a periampullary pathologic disorder requiring operation. the diagnosis of diarrhea was made if patients reported three or more bowel movements per day or if the total volume of their movements in a day was 0.5 liters or greater. weight loss was quantified by patient history at the time of the preoperative visit. nine preoperative serum chemistries (total bilirubin, alkaline phosphatase, sgot, total protein, albumin, amylase, glucose, calcium and phosphorous), five hematologic parameters (hematocrit, hemoglobin, white blood cell count, prothrombin time, and partial thromboplastin time), and three serum tumor marker values (cea, ca-19 - 9, and ca-125) were obtained from routine blood draws either in the preoperative clinic or during a hospitalization close to the time of operation. eleven perioperative variables including pre - operative biliary stenting (endoscopic or percutaneous transhepatic), pre - operative transfusion, pre - operative total parenteral nutrition (tpn), pre - operative bowel preparation, estimated intra - operative blood loss (ml), intra- and post - operative transfusions, operative time (minutes), type of resection (standard versus pylorus preservation), type of pancreaticojejunostomy (invagination or end - to - side duct to mucosa), type of intraperitoneal drains used (penrose or closed suction jackson - pratt drains), and gastrostomy tube placement were identified from the patient medical records, anesthesiologist 's records, and the operative reports. all specimens were reviewed by the staff pathologist at indiana university medical center with the majority of specimens also undergoing a secondary review by a dedicated pancreatic pathologist. histopathologic diagnosis, tumor size, tumor differentiation (well, moderate, poor, none), lymph node status (positive, negative), and surgical margin status (positive, negative) were routinely reported. margins analyzed included the common bile duct, pancreatic neck, and duodenum or stomach. retroperitoneal (uncinate) soft tissue margins were inconsistently analyzed early in this series (19802002), but since 2002, at our facility, standardized retroperitoneal margin assessment and analysis have been carried out based on ajcc guidelines (37). clinical outcomes variables that were assessed included the following : in - hospital mortality, overall complications, and specific complications such as cardiopulmonary, delayed gastric emptying (dge), sepsis, wound infection, intra - abdominal abscess, hemorrhage, and hospital length of stay (los). delayed gastric emptying was defined in this cohort as the inability to take a regular diet after postoperative day no. 10. survival was determined from the most recent encounter at indiana university hospital and was cross - referenced with the clarian cancer registry database and the social security database. twelve surgeons operated on patients included in this study who underwent either pylorus preserving or classic (hemigastrectomy) pancreaticoduodenectomy. reconstruction was undertaken with an isoperistaltic limb of jejunum in retrocolic fashion and anastomosed with an end - to - side pancreaticojejunostomy, followed by an end - to - side choledochojejunostomy and an (antecolic or retrocolic) end - to - side duodenojejunostomy or gastrojejunostomy. the pancreaticojejunostomy was performed using a duct - to - mucosa anastomosis (n = 453) or, alternatively, an invaginated anastomosis (n = 52) based on surgeon preference. only one surgeon used this technique predominately, accounting for 63% of their total pd. during this period at our institution, the pancreaticojejunostomy and choledochojejunostomy were drained routinely with penrose drains to gravity or closed suction drains. finally, some patients in this series underwent elective gastrostomy for postoperative decompression and alimentation. the association of categorical factors with survival was assessed using the kaplan - meier method (km) and was tested using the log - rank test. the association of continuous variables with survival was analyzed using a cox 's proportional hazards regression model and tested via the wald test. analyses were performed with a forward stepwise logistic regression model selection procedure where the probability of inclusion of a factor in the model was set at 20% and the probability of removal factor from the model was 20%. statistical significance was set at p.05. the mean age was the same in patients with pf (58 years ; range 3079) compared to those without pf (58 years ; range 1593). sixty - five patients underwent pancreaticoduodenectomy in the 1980s with the remainder being performed from 1990 and 2000. the incidence of pf as a function of time by decade (1980 's = 9% ; 1990 's = 6% ; 2000 's = 10%) or by year (p = ns) did not change significantly over the course of the study period. pancreatic fistula was more common in males, with this difference approaching statistical significance in univariate analysis, (p =.06). of the twelve preoperative patient symptoms tracked, none were associated with a significant difference in the rate of fistula formation (data not shown). notably, a preoperative diagnosis of diabetes was present in a greater proportion of patients who did not have pf ; however, this result was not statistically significant. only serum glucose showed a significant association (p =.04) with pf formation. serum glucose tended to be higher in patients who did not have a pf corroborating the trend in diabetes incidence previously noted. preoperative biliary stenting was done in 211 patients, 68 of whom had percutaneous transhepatic biliary stenting, and 143 had endoscopic stenting. preoperative biliary stenting (combined percutaneous and endoscopic groups) showed no significant difference in pf rates when compared to patients who were not preoperatively stented (9% stented group (20/211) versus 8% without stenting (26/299)). when subclassified into percutaneous transhepatic or endoscopic stenting however, a significantly higher incidence of pf was found in the percutaneous transhepatic stent group, 16% (11/68) compared to endoscopic stent group 6% (9/143) (p =.04). information about preoperative mechanical bowel preparation was not tracked in the latter half of our series ; however, among patients in whom preoperative mechanical bowel preparation status was known, a significantly higher incidence of pf was identified in patients who did not undergo mechanical bowel preparation (19% (6/31) versus 6% (14/226), p 4 months (1). the diagnosis of pf was made on average on postoperative day 8 and these patients experienced longer lengths of hospital stay. the median length of stay in the pf group was 25 days, whereas it was only 12 days in the no pf group (p <.001). based upon international study group for pancreatic fistula (isgpf) grading guidelines, this series included 10 grade a fistulas, 23 grade b fistulas, and 13 grade c fistulas. forty - five of 46 pf (98%) closed without reoperation with a mean time to closure of 34 days (range 393 days). twenty - three patients (all grade 13 grade c fistulas and 10 grade b fistulas) were treated with antibiotics. ten patients (5 grade c and 5 grade b fistulas) were treated with octreotide. this timing of closure was not significantly different with / without octreotide treatment (39 5 versus 25 5) or with / without antibiotic treatment (36 5 versus 29 6). thirty - six patients required tpn for an average of 32 days (range 590 days). time to closure was not affected by nutrition route (enteral versus parenteral), daily pf output, or the level of amylase / lipase in the pf fluid analysis. average daily fistula output was 163 26 cc but with a wide range (502300 cc). computed tomography (ct) directed percutaneous drainage of an intra - abdominal fluid collection was required in 11 of 46 patients with a pf. in seven of these patients, notably, there was a trend of delayed fistula closure when patients required percutaneous drainage of any intra - abdominal fluid collection postoperatively (42 7 days with versus 30 5 days without, p =.09). a multivariate analysis was performed of all parameters with a forward stepwise logistic regression model (tables 6(a)6(c)). this analysis indicated that independent predictive factors for the formation of a pf were as follows : invaginated anastomosis (or 3.30, p =.01) and closed suction drainage (or 2.24, p =.05). a diagnosis of pancreatitis (or 0.22, p =.05) and preoperative endoscopic biliary stenting (or 0.34, p =.05) were independent protective factors against pf. because the type of drain was highly correlated with individual surgeon, in a separate assessment we performed a multivariate analysis excluding drain type (table 6(b)). in this analysis, invaginated pancreaticojejunostomy (or 4.56, p =.002) remained a significant predictive factor of pf and the diagnosis of pancreatitis (or 0.22, p =.05) remained an independent protective factor. while the presence of an endoscopic stent did not reach significance, the presence of a preoperative percutaneous transhepatic biliary stent (or 2.43, p =.07) approached significance. a multivariate analysis was also performed on the subgroup of patients with periampullary adenocarcinomas (table 6(c)). the only independent predictor of pf formation in this group was an invaginated pancreaticojejunostomy (or 11.8, p =.0002). female gender (or 0.238, p =.03) and endoscopic stent (or 0.194, p diabetes (or 0.146, p =.07) demonstrated a trend as a protective factor against pf formation. in this study, we report our experience with pf in a series of 510 consecutive pancreaticoduodenectomies performed over a 22-year period. our incidence of pf was 9% which appears to be comparable to the pf rate of 914% reported in other specialized centers [110 ]. it is difficult to compare the incidence and severity of pf without standardization of the diagnosis, terms, and severity of this complication. it is hopeful that the standardized definitions of pf as put forth by the isgpf will likely allow for more equitable comparison among institutions. the risk of pf formation appears to be multifactorial involving demographic, preoperative, intraoperative, and pathologic factors. one prior study has reported that male sex was a significant predictor of pf. in this study, male gender only approached significance as a univariate predictor of pf formation in the overall group of patients undergoing pancreaticoduodenectomy. in our periampullary adenocarcinoma subgroup analysis, females had a lower incidence of pf and these results showed a trend as an independent predictor of pf on multivariate analysis. advanced age cited by some as predictive of pf was not recognized as a predictor in this series [23, 24 ]. a higher incidence of pf was identified in patients who did not undergo mechanical bowel preparation. this association to our knowledge has not been reported before and so is an intriguing finding. perhaps the absence of intestinal succus or stool in the colon minimizes pressure in the jejunum limb translating into reduced pf rates. intraoperative blood loss cited by some as predictive was also not recognized as a significant factor in this series [23, 24 ]. type of pancreaticojejunostomy anastomosis has also been cited by others in the literature to be a predictor of pf. this study showed that the type of pancreaticojejunostomy reconstruction (invaginated versus end - to - side) was significantly associated with pf in both the whole group and periampullary adenocarcinoma subanalysis. a recent metaanalysis addressing this particular association found a higher incidence of pf in patients who had invaginated pancreaticojejunostomy (26%) versus a duct - to - mucosa (16%) type of anastomosis. these findings are in contrast to a randomized control trial of 144 patients performed in italy by bassi. which showed no significant difference between invaginated and duct - to - mucosa anastomoses in pd. our pancreaticobiliary group is currently participating in a prospective randomized trial with thomas jefferson university to determine whether or not there is a difference in pf rate between invaginated and duct - to - mucosa pancreaticojejunostomy in pd. preoperative biliary stenting has been an area where some groups show an association with pf. a study from hopkins suggests that preoperative stenting is associated with an increased risk of pf formation. on the one hand, preoperative endoscopic stents are actually protective in our subgroup of patients with periampullary adenocarcinoma, while those patients who had preoperative percutaneous transhepatic biliary (ptb) stenting showed an increased risk of pf formation. other authors have also shown that preoperative endoscopic stenting decreases the incidence of postoperative pf. our study also suggests that closed suction drainage may be a predictor of pf formation. the memorial sloan kettering group has shown a lower incidence of pf in patients who did not have intraperitoneal drainage following pd. in our series both penrose drains and closed suction drains were used and the penrose drain group showed a lower incidence of pf formation. this finding implies that active suction drainage may have a deleterious effect on pf formation. a confounding factor in our study was that the penrose type drain was used largely by the highest volume surgeon in our series who also had a comparably low pf rate. drain type covaried so tightly with individual surgeons such that it was not possible to separate whether drain type or individual surgeon was more predictive in our multivariate model. one factor which appears to be a consistent is that the texture of the gland is significantly associated with pf formation. stratified patients in a trial according to the texture of the gland and found that patients with a firmer texture gland had a lower incidence of pf. other studies have also supported the association between soft pancreatic gland texture and the risk of pf [25, 30, 31 ]. our data is indirectly supportive that the texture of the gland is predictive of pf formation in those patients with both duodenal and ampullary adenocarcinomas, who often have a normal (i.e., soft) gland texture ; both had a higher incidence of pf formation in our series but intraoperative assessment of the gland at the time of operation was not available in our retrospective database. other investigators have associated a small pancreatic duct as a contributing factor to pf formation [22, 32 ]. pancreatic duct size was not prospectively tracked in our series of patients although it should be noted that this particular variable is often difficult to separate between soft textures of the gland because typically soft glands also have small pancreatic ducts [19, 22 ]. although not addressed specifically in our analysis, individual surgeons tend to vary widely in their postoperative rate of pf. in particular, two specific surgeons in this series (out of the 12 participants) had significantly different pf rates from the average of their remaining peers. one surgeon had a significantly lower incidence of pf (4% compared to 14% for all others combined, p <.001) while the other surgeon had a significantly higher incidence of pf (18% versus 8% for all others combined, p =.04). while these differences were accounted for, in part, by the differences in pancreatic pathology in each surgeon 's cohort, this issue brings up the surgeon as a significant variable in the incidence of pf formation. achilles heel of pancreaticoduodenectomy and novel approaches continue to be put forward to reduce its incidence [3336 ]. although historically, pf were associated with a mortality rate of 20 to 40% [3, 7, 8 ], current advances in radiologic imaging and interventional radiologic techniques, antibiotics, and critical care medicine have considerably reduced the mortality rates from pf. our data is consistent with this trend since in our series of patients with pf, there were no in - hospital mortalities. nonetheless, pfs continues to cause significant morbidity, prolonged hospital stay, and increased hospital cost. our data supports these observations since patients with pf had a greater total number of complications, a higher incidence of septic complications, and a higher reoperation rate. in addition, our patient 's length of hospital stay was twice that of patients who did not have a pf. based on univariate analyses, gender, diabetes, preoperative glucose level, length of operation, bowel preparation, biliary stenting (endoscopic versus percutaneous), anastomotic technique (invaginated versus duct - to - mucosa), intraperitoneal drain choice (passive / gravity versus closed - suction), and pathology (pancreatitis, duodenal cancer) may influence pf formation. in multivariate analyses, invaginated anastomosis, closed suction drainage, and percutaneous biliary stenting all increased the risk of pf while pancreatitis, endoscopic biliary stenting, and female gender conferred protection against pf. the influence of the individual surgeon on pf is also an extremely important factor to consider although difficult to separate from other variables such as gender, pancreatic pathology, or biliary stenting in a retrospectively designed study. in conclusion, in this series the development of pf following pancreaticoduodenectomy was predicted by demographics (gender), preoperative procedures (biliary stenting), intraoperative technique (anastomosis, drainage, individual surgeon), and pancreatic pathology (pancreatitis). outcomes in patients with pf are remarkable for a higher rate of septic complications, an increased incidence of reoperations, and a longer hospital stay without significant difference in overall mortality rate. preoperative biliary stenting, type of pancreaticoenteric anastomosis, and intraperitoneal drain usage are controllable factors in pf formation that surgeons should continue to investigate to reduce its incidence following pd. | pancreatic fistula continues to be a common complication following pd. this study seeks to identify clinical factors which may predict pancreatic fistula (pf) and evaluate the effect of pf on outcomes following pancreaticoduodenectomy (pd). we performed a retrospective analysis of a clinical database at an academic tertiary care hospital with a high volume of pancreatic surgery. five hundred ten consecutive patients underwent pd, and pf occurred in 46 patients (9%). perioperative mortality of patients with pf was 0%. forty - five of 46 pf (98%) closed without reoperation with a mean time to closure of 34 days. patients who developed pf showed a higher incidence of wound infection, intra - abdominal abscess, need for reoperation, and hospital length of stay. multivariate analysis demonstrated an invaginated pancreatic anastomosis and closed suction intraperitoneal drainage were associated with pf whereas a diagnosis of chronic pancreatitis and endoscopic stenting conferred protection. development of pf following pd in this series was predicted by gender, preoperative stenting, pancreatic anastomotic technique, and pancreas pathology. outcomes in patients with pf are remarkable for a higher rate of septic complications, longer hospital stays, but in this study, no increased mortality. |
tissue samples simply and clearly indicate the presence or absence of cancer, but may contain other histological aspects, such as nodular hyperplasia (so - called benign prostatic hyperplasia, or bph), prostatitis, atrophy, adenosis, prostate intraepithelial neoplasia (pin, which is distinguished as low - grade pin, or lgpin, and high - grade pin, or hgpin), and atypical small acinar proliferation (asap). several studies have demonstrated that this diagnosis is predictive of malignancy in a subsequent biopsy specimen in 34% to 60% of cases. the evidence for predictors of prostate cancer after an initial diagnosis of asap is contradictory and uncertain. some authors have reported that no clinical or pathological findings can increase the accuracy of prediction of cancer. however, several studies have shown various parameters as predictive factors in prostate cancer detection [1,7 - 9 ]. hence, we evaluated the clinical factors that predicted the detection of prostate cancer at rebiopsy. from january 2003 to december 2008, 3,130 men underwent a trus - guided (iu-22 ; philips, andover, ma, usa) prostate biopsy with an 18-gauge needle biopsy gun (acecut ; tsk laboratory, tochigi, japan) at our institution, and 244 (7.8%) were diagnosed as having asap. we advised men with asap to undergo rebiopsy within 3 to 6 months, irrespective of follow - up prostate - specific antigen (psa) values. of 244 cases of asap, 170 patients had at least one more repeat biopsy ; the other 74 had no further biopsy at our institution owing to patient preference, concurrent prostate cancer, concomitant morbidities, or loss to follow - up. rebiopsied patients were classified into a prostate cancer group and a noncancer group according to final pathological diagnosis. we categorized one patient with asap as the final diagnosis (all results for 4 consecutive rebiopsies were asap) in the noncancer group. we retrospectively reviewed our database to obtain age, initial psa, psa density (psad), psa velocity (psav), total prostate volume (tpv), and transitional zone volume of the prostate (tzv) in all 170 patients. prostate volume was calculated by the formula 0.523x transverse diameter x anteroposterior diameter x longitudinal diameter measured by trus. the number of needle biopsies was 6 cores in patients with tpv less than 30 ml and 12 cores in patients with tpv of 30 ml or more. immunostains with high molecular weight cytokeratin (34e12) and p63 were added to initial h&e stains. univariate analysis (mann - whitney u test) was performed to compare the clinical patterns of cancer patients with those of the noncancer group at rebiopsy. multivariate logistic regression analysis was used to identify any correlation between the detection rate of prostate cancer and the previously mentioned factors, with control for potentially confounding factors. all data analyses were performed by using spss ver. 15.0 (spss inc., chicago, il, usa). the mean age of the 170 patients was 74.0 years (range, 58 - 85 years), the mean initial psa value was 10.7 ng / ml (range, 1.4 - 89.9 ng / ml), the mean psad was 0.30 ng / ml / ml (range, 0.03 - 2.75 ng / ml / ml), the mean tpv was 39.6 ml (range, 12.6 - 133.8 ml), and the mean tzv was 19.6 ml (range, 4.2 - 99.0 ml). the psav was known for 155 of the total 170 patients ; the mean psav of these 155 men was 2.8 ng / ml / year (range, -77.0 - 453.2 ng / ml / year) (table 1). a total of 57 patients (33.5%) with asap were ultimately diagnosed with prostate cancer. the cancer detection rates of the 1st, 2nd, 3rd, and 4th repeat biopsy were 24.1% (41/170), 34.1% (14/41), 18.2% (2/11), and 0% (0/2), respectively. in 57 patients with a final diagnosis of prostate cancer, the mean age was 74.6 years, the mean initial psa was 12.2 ng / ml, the mean psad was 0.36 ng / ml / ml, the mean psav was 12.7 ng / ml / year, the mean tpv was 35.7 ml, and the mean tzv was 16.0 ml. in 113 patients with no cancer, the mean age, mean initial psa, mean psad, mean psav, mean tpv, and mean tzv were 73.7 years, 9.9 ng / ml, 0.27 ng / ml / ml, -2.2 ng / ml / year, 41.6 ml, and 21.5 ml, respectively (table 2). univariate analysis showed that psad (p=0.002), psav (p=0.001), tpv (p=0.035), and tzv (p=0.005) differed significantly between the prostate cancer and non - cancer groups (table 2). the results of the multivariate analysis showed that psad (p=0.022), psav (p<0.001), and tpv (p=0.037) had a statistically significant correlation with cancer detection (table 3). asap has been described by several terms, but today, pathologists commonly adopt asap or ' atypical foci suspicious but not diagnostic of malignancy ' to define a diagnostic category including a broad group of entities. asap is not a single entity, but rather encompasses a diverse array of lesions such as benign crowded glands, basal cell hyperplasia, adenosis, reactive atypia, and atypical glandular proliferations suspicious for carcinoma, which can not be accurately diagnosed for various reasons such as insufficient amount of specimen or biopsy - induced mechanical distortion. iczkowski mentioned that biopsy cores meriting an asap diagnosis fall into 2 broad categories : (i) qualitatively inadequate cytoarchitectural features. a focus may contain about a dozen acini showing such features as probable loss of the basal cell layer and infiltrative pattern but with a continuum of cytologic features that fall short of the cytologic and histologic criteria for cancer. the acini in the focus display cytoarchitectural findings compatible with cancer but the size of the focus is the major limitation. iczkowski reported that the incidence of asap on the basis of their most recent study was 197 (3.3%) of 6,026 men undergoing prostate biopsy ; previous studies reported incidences of 1.5% to 9.0%. several studies have demonstrated that this diagnosis is predictive of malignancy in a subsequent biopsy specimen in 34% to 60% of cases. asap has been subclassified according to degree of suspicion for prostate cancer by several investigators. chan and epstein found cancer in 61% of patients with atypical biopsy favoring a cancer versus 33% of patients with atypical biopsy favoring a benign process. however, scattoni suggested that the subclassification of lesions into asap highly suspicious for cancer and asap favoring a benign diagnosis was not clinically useful, and they mentioned that the stratification scheme is too subjective to be reproducible, even among expert diagnosticians. immunostains with 34e12 and p63 can aid in the investigation of asap, but immunohistochemically negative patterns are not diagnostic of prostate cancer (false - negative staining). therefore, a positive marker such as alpha - methylacyl coenzyme a racemase (amacr / p504s) has also been used. amacr is strongly and diffusely positive in 97% to 100% of prostate cancers and can convert atypical foci to cancer in approximately 10% of cases [17 - 19 ]. however, staining with amacr is not an error - free method because of positivity in 8% of 12% of benign glands. the evidence for predictors of prostate cancer after an initial diagnosis of asap is contradictory and uncertain. iczkowski found that neither age, serum psa, digital rectal examination (dre), number of positive foci, nor histological findings was predictive of cancer. ebstein and herawi also reported that no clinical or pathological features contributed to or predicted prostate cancer. however, park reported that dre and patient age were independent predictors of cancer in patients with ' atypia '. borboroglu showed that psav was the only significant predictor of positive repeat biopsy, whereas scattoni claimed prostate volume and hgpin together with asap were the only predictive factors in prostate cancer detection. mearini commented that the free / total psa ratio and prostate volume seemed to be independent predictors of prostate cancer at rebiopsy and that the clinical value of psad in the larger prostate gland is altered by the bph component, which prevails over the tumor. scattoni and ficarra suggested that the lower rate of prostate cancer in larger prostate glands could be due to sampling error. in our study, psad, psav, and tpv were significant variables predicting cancer detection in patients with asap in the multivariate analysis, even though tzv was also a significant factor in the univariate analysis. brausi found that 100% of 25 patients with isolated asap who underwent radical prostatectomy had cancer. those authors suggested that immediate radical prostatectomy may be the treatment of choice for young patients with asap. however, performing radical prostatectomy in patients diagnosed as having asap is not acceptable clinical practice in most countries. ebstein and herawi, scardino recommend that all men with asap undergo rebiopsy within 3 to 6 months, irrespective of follow - up psa values. allen reported that prostate cancer was detected in 84.8% of cases at either the same sextant site as the previous biopsy, at adjacent ipsilateral sites, or at adjacent contralateral sites (47.8% of the cancer was detected in the same sextant site) and recommended that 3 cores should be sampled from the site of the initial atypical site, 3 cores from the adjacent ipsilateral and adjacent contralateral sites, and 1 core from other sextant sites. on the other hand, scattoni found a precise spatial concordance between asap and cancer in only 33% of the cases in a multisite scheme study, which was not statistically different from the probability of finding cancer in adjacent sites or in nonadjacent sites. they reported that 12 cores might not be sufficient to correctly sample prostate glands larger than 50 ml in which asap is present. according to our study, therefore, we suggest that patients diagnosed as having asap should undergo more extended repeat biopsy with increasing biopsy cores in patients with large prostate volumes. (i) immunohistochemical stains with high molecular weight cytokeratin (34e12) and p63 were performed in our institution, but stain with amacr could not be performed for all patients because it was introduced in the middle of our investigation period. (ii) a special protocol for repeat biopsy could not be established because our investigation was a retrospective study. at the repeat biopsy, the number of needle biopsy cores (6 cores in patients with prostate volume less than 30 ml and 12 cores in patients with prostate volume of 30 ml or more) was not different from that of the initial biopsy cores, although extended biopsy with additional biopsy is appropriate in initial asap patients. although we did not intend this, these biopsy strategies reinforced our argument of more extended repeat biopsy in patients with a large prostate volume, because men with large volumes showed a lower incidence of cancer detection despite these strategies. (iii) although some authors have suggested that the free / total psa ratio and prostate volume seem to be independent predictors of prostate cancer at rebiopsy, we excluded the free / total psa ratio from the clinical factors in our study because free psa was not routinely examined for all patients. psad, psav, and tpv were significant predictive factors of a diagnosis of prostate cancer at a repeat biopsy in men with an initial diagnosis of asap. psad and psav were higher and tpv was smaller in the cancer group than in the noncancer group. although repeat biopsy is necessary within 3 to 6 months, irrespective of psa values, the follow - up of psa may help to estimate the probability of cancer. | purposethe factors that predict prostate cancer detection on repeat biopsy were evaluated in patients with atypical small acinar proliferation (asap) on the initial biopsy.materials and methodsfrom 2003 to 2008, 3,130 men with suspected prostate cancer underwent a prostate needle biopsy, and 244 (7.8%) were diagnosed as having asap. one hundred seventy of 244 patients were rebiopsied at least once more. they were classified into a prostate cancer group and a noncancer group according to the final pathological diagnosis. the database of rebiopsied patients included age, initial prostate - specific antigen (psa), psa density (psad), psa velocity (psav), total prostate volume (tpv), and transitional zone volume of the prostate (tzv). we compared differences in the aforementioned parameters between the 2 groups.resultsa total of 57 patients (33.5%) with asap were ultimately shown to have prostate cancer. univariate analysis showed that psad (p=0.002), psav (p=0.001), tpv (p=0.035), and tzv (p=0.005) differed significantly between the cancer and noncancer groups. the results of the multivariate analysis showed that psad (p=0.022), psav (p<0.001), and tpv (p=0.037) had a statistically significant correlation with cancer detection.conclusionspsad, psav, and tpv are predictive factors of prostate cancer in patients with an initial diagnosis of asap of the prostate. although repeat biopsy is mandatory irrespective of psa values, the follow - up of psa may help to estimate the probability of cancer in these men. |
experimental animals : six intact purpose - bred cats (3 males and 3 females), 1 to 3 years of age [1.8 1.0 (mean standard deviation) years ] and weighing from 3.0 to 5.4 kg [4.3 0.8 (mean standard deviation) kg ], were used in the present study. all cats were judged to be in good to excellent health based upon a physical examination. food was withheld for at least 12 hr before drug administration, but the cats were allowed free access to water prior to each treatment. guide for the care and use of laboratory animals prepared by rakuno gakuen university. the animal care and use committee of rakuno gakuen university approved this study (approved no. study design : the cats received 5 treatments with a minimum 14-day washout period (14 to 685 days) between treatments. in each treatment, the cats were administered one of the following 5 doses of alfaxalone - hpcd (alfaxan, jurox pty. rutherford, nsw, australia) : an i m dose of 1 mg / kg (im1), 2.5 mg / kg (im2.5), 5 mg / kg (im5), 10 mg / kg (im10) or an iv dose of 5 mg / kg (iv5). the total volumes of injection of alfaxalone - hpcd were 0.45 0.08, 1.0 0.2, 2.1 0.4, 4.5 0.8 and 1.9 0.4 ml for the im1, im2.5, im5, im10 and iv5 treatments, respectively. the i m doses were injected into the dorsal lumbar muscle of the cats by using a 23-gauge, 1-inch needle (top injection needle, top co., ltd., the iv dose was administered for over approximately 60 sec through a 22-gauge catheter (supercath, medikit co., ltd., sedative effects and cardio - respiratory function were evaluated in the cats before (baseline) and at 2, 5, 10, 15, 20, 30, 45, 60, 90, 120, 150 and 180 min after starting the drug administration. evaluation of sedative effects : the sedative effects of alfaxalone - hpcd were subjectively evaluated using a composite measure scoring system modified from a sedative scale previously used in dogs. the observer (j. t.) was not blinded, but responsible for the evaluation using this scoring system throughout the present study. the scoring system consisted of 5 categories : spontaneous posture, placement on side, response to noise, jaw relaxation and general attitude. these categories were rated in scores 0 to 2 for jaw relaxation, 0 to 3 for placement of side and general attitude, or 0 to 4 for spontaneous posture and response to noise based on responsiveness expressed by the cats (table 1table 1.composite measure scoring system for evaluating sedative effects in catsscorespontaneous posturestanding0tired and standing1lying but can rise2lying with difficulty rising3unable to rise4placement on sideresists strongly0modest resistance1slight resistance2no resistance3response to noisejump0hears and moves1hears and twitches ear2barely perceives3no response4jaw relaxationpoor0slight1good2general attitudeexcitable0awake and normal1tranquil2stuporous3sedation score016this scoring system consisted of 5 categories (spontaneous posture, placement on side, response to noise, jaw relaxation and general attitude). these categories were rated in scores 0 to 2, 0 to 3 or 0 to 4 based on responsiveness expressed by the cats. the sedation score was calculated as a sum of scores for the 5 categories : spontaneous posture, placement on side, response to noise, jaw relaxation and general attitude.). the sedation score was calculated as a sum of scores in the 5 categories (a maximum of 16). in addition, times to onset of lateral recumbency, the first appearance of spontaneous movement, head lift and unaided standing after starting the drug administration, and the durations of lack of spontaneous movement and maintenance of lateral recumbency were recorded. this scoring system consisted of 5 categories (spontaneous posture, placement on side, response to noise, jaw relaxation and general attitude). these categories were rated in scores 0 to 2, 0 to 3 or 0 to 4 based on responsiveness expressed by the cats. the sedation score was calculated as a sum of scores for the 5 categories : spontaneous posture, placement on side, response to noise, jaw relaxation and general attitude. measurements of cardio - respiratory valuables : lead ii electrocardiography (ecg), heart rate (hr ; beats / min), rectal temperature (rt;c), mean arterial blood pressure (mabp ; mmhg) and percutaneous oxygen saturation of hemoglobin (spo2;%) were recorded before and after the drug administration until reliable data were collected. ecg, hr and spo2 were recorded by a patient monitoring system (ds-7210, fukuda denshi co., ltd.,. respiratory rate (rr ; breaths / min) was counted by observing thoracic movements. rt was measured with a digital thermometer (thermo flex for animal, astec co., ltd., mabp was indirectly measured by an oscillometric method (pet map, ramsey medical, inc., hudson, oh, u.s.a.) using a blood pressure cuff approximately 40% circumference of the measuring site in width placed around the clipped tail base of each cat. the arterial blood pressure was measured three times at each assessment, and the average of these measurements was defined as arterial blood pressure. statistical analysis : the sedation score was reported as median quartile deviation and analyzed by the kruskal - wallis test to assess the changes with time for each treatment. differences in the sedation score among the treatments were compared by the kruskal - wallis test with the steel - dwass test for post hoc comparisons. times related to the sedative effects and cardio - respiratory variables were reported as mean standard deviation. times related to the sedative effects were compared by one - way (treatment) factorial anova with the bonferroni test for post hoc comparisons among treatments. the cardio - respiratory variables were analyzed using one - way (time) factorial anova with the dunnet test for post hoc comparisons for each treatment. observations and/or perceived adverse effects related to drug administration were compared between treatments by use of chi square test. the times required for the i m injection were 5 5, 11 9, 8 5 and 35 18 sec in the im1, im2.5, im5 and im10 treatments, respectively. in the im10 treatment, the time required for the i m injection was longer compared to the im1, im2.5 and im5 treatments (p<0.001, p=0.006 and p=0.002, respectively). vocalization during the i m administration was observed in 3 cats (50%), 2 cats (33%), 4 cats (67%) and 4 cats (67%) receiving the im1, im2.5, im5 and im10 treatments, respectively. on the other hand, no cat receiving the iv5 treatment showed discomfort (vocalization, attempting to bite at injection site or aggressively excited behavior) during the administration. there was no significant difference in the incidence of vocalization during the i m administration between the treatments (p=0.605). no cats showed discomfort (excessive grooming at injection site or avoiding touching the injection site), and swelling, redness and/or other inflammatory changes around the i m injection site after the experiment on each occasion. the sedative effects : times associated with the sedative effects of each treatment are shown in table 2table 2.times related to sedative effects after starting intramuscular (i m) or intravenous (iv) administration of alfaxalone - hpcd in catsalfaxalone administration1 mg / kg im2.5 mg / kg im5 mg / kg im10 mg / kg im5 mg / kg ivtime to onset of lateral recumbency (sec)451 129 213 143152 85128 2227 14time to the first appearance of spontaneous movement (min)15 10 27 742 1274 1229 12time to head lift (min)22 10 40 1575 18100 1848 6time to unaided standing (min)30 10 60 1095 24121 2259 6duration of lack of spontaneous movement (min)10 11 21 835 1672 1229 12duration of maintenance of lateral recumbency (min)16 12 40 1576 21115 2250 5data are expressed as mean standard deviation. statistical analysis was performed among three treatments (im2.5, im5 and im10), because of small samples in the im1 treatment.. the cats ceased to move after being recumbent, except for one cat each after the im1 and im2.5 treatments. all cats after the im2.5, im5 and im10 treatments showed lateral recumbency within 7 min after starting the injection. on the other hand, the im1 treatment produced lateral recumbency in only 3 cats (50%), and consequently, it was impossible to attempt statistical comparison using this treatment group. therefore, the times related to the sedative effects were only statistically compared amongst the im2.5, im5, im10 and iv5 treatments. the times to head lift and unaided standing and duration of maintenance of lateral recumbency were significantly longer in the im5 (p=0.004, p=0.014 and p=0.009, respectively) and im10 treatments (p<0.001, p<0.001 and p<0.001, respectively), compared to the im2.5 treatment. the times to first appearance of spontaneous movement and durations of lack of spontaneous movement were markedly longer in the im10 treatment, compared to the im2.5 (p<0.001 and p<0.001) and im5 treatments (p<0.001 and p=0.005). the times to head lift and unaided standing were significantly longer in the im5 than those in the iv5 treatment (p=0.033 and p=0.011). all observations were completed at 45 min after the im1 treatment, at 90 min after the im2.5 and iv5 treatments and at 120 min after the im5 treatment, because the cats fully recovered and could walk normally. statistical analysis was performed among three treatments (im2.5, im5 and im10), because of small samples in the im1 treatment. 1.median (quartile deviation) sedation score in 6 cats before and after starting intramuscular (i m) or intravenous (iv) administration of alfaxalone - hpcd. based on responsiveness expressed by the cats, the categories of a composite measure scoring system were rated in scores 0 to 2 for jaw relaxation, 0 to 3 for placement of side and general attitude, or 0 to 4 for spontaneous posture and response to noise (see table 1). the sedation score was calculated as a sum of scores in these 5 categories. a : significant difference from 1 e : significant difference from 5 mg / kg iv (p<0.05).. each treatment produced a higher sedation score compared to each baseline value (p<0.001). a maximum sedation score of 16 was observed in 2 cats (33%) after the im2.5 treatment and all cats (100%) each after the im5, im10 and iv5 treatments. the median sedation scores peaked at 10 min after the im1 treatment, 15 min after the im2.5 treatment, 10 min after the im5 treatment, 10 to 20 min after the im10 treatment and 2 to 5 min after the iv5 treatment. the sedation scores in cats administered the im5 and im10 treatments were significantly higher compared to the im1 (p<0.001 and p<0.001) and im2.5 treatments (p=0.029 and p<0.001). there was no significant difference in the sedation score between the im5 and iv5 treatments (p=0.984). median (quartile deviation) sedation score in 6 cats before and after starting intramuscular (i m) or intravenous (iv) administration of alfaxalone - hpcd. based on responsiveness expressed by the cats, the categories of a composite measure scoring system were rated in scores 0 to 2 for jaw relaxation, 0 to 3 for placement of side and general attitude, or 0 to 4 for spontaneous posture and response to noise (see table 1). the sedation score was calculated as a sum of scores in these 5 categories. a : significant difference from 1 e : significant difference from 5 mg / kg iv (p<0.05). during the recovery period, ataxia was observed in all cats (100%) administered the im2.5, im5, im10 and iv5 treatments. transient muscular tremors were observed in 2 cats (33%), 4 cats (67%), 6 cats (100%), 6 cats (100%) and 5 cats (83%) administered the im1, im2.5, im5, im10 and iv5 treatments, respectively. opisthotonus - like posture was also observed in one cat (17%), 4 cats (67%), 3 cats (50%) and 3 cats (50%) administered the im2.5, im5, im10 and iv5 treatments, respectively (fig. 2.opisthotonus-like posture observed in cats during the recovery period. during the recovery period, opisthotonus - like posture was observed in one cat (17%) received 2.5 mg / kg of intramuscular (i m) alfaxalone, 4 cats (67%) received 5 mg / kg of i m alfaxalone, 3 cats (50%) received 10 mg / kg of i m alfaxalone and 3 cats (50%) received 5 mg / kg of intravenous (iv) alfaxalone. a cat showed opisthotonus - like posture from 60 to 90 min after the im5 treatment (a). another cat showed opisthotonus - like posture from 90 to 120 min after the im10 treatment (b).). in addition, paddling of the forelimbs was observed in 4 cats (67%) and one cat (17%) administered the im10 and iv5 treatments, respectively, and running was observed in one cat (17%) each administered the im2.5, im5 and iv5 treatments. in addition, one cat (17%) vomited during the recovery period after the im10 treatment. opisthotonus - like posture observed in cats during the recovery period. during the recovery period, opisthotonus - like posture was observed in one cat (17%) received 2.5 mg / kg of intramuscular (i m) alfaxalone, 4 cats (67%) received 5 mg / kg of i m alfaxalone, 3 cats (50%) received 10 mg / kg of i m alfaxalone and 3 cats (50%) received 5 mg / kg of intravenous (iv) alfaxalone. a cat showed opisthotonus - like posture from 60 to 90 min after the im5 treatment (a). another cat showed opisthotonus - like posture from 90 to 120 min after the im10 treatment (b). changes in cardio - respiratory valuables : the cardio - respiratory variables are summarized in table 3table 3.changes in cardio - respiratory variables before and after starting intramuscular (i m) or intravenous (iv) administration of alfaxalone - hpcdminutes after starting administration of alfaxalonebaseline2510152030456090120150180rt (c)im138.1 0.438.4 0.438.1 0.238.2 0.338.0 0.338.0 0.337.8 0.437.7 0.6n.d.n.d.n.d.n.d.n.d.im2.538.4 0.338.5 0.338.5 0.238.3 0.238.0 0.237.9 0.2 37.5 0.1 37.4 0.2 37.7 0.4 37.8 0.3n.d.n.d.n.d.im538.3 0.238.8 0.4 38.7 0.438.5 0.338.2 0.338.1 0.337.7 0.2 37.2 0.2 37.0 0.2 37.3 0.5 38.2 0.4n.d.n.d.im1038.3 0.438.5 0.438.4 0.538.3 0.538.1 0.5 37.9 0.537.6 0.437.1 0.4 36.6 0.4 35.7 0.7 36.3 1.0 36.9 1.0 36.9iv538.5 0.538.3 0.538.1 0.437.8 0.437.7 0.4 37.4 0.4 37.0 0.4 36.8 0.4 37.2 0.8 37.7 0.4n.d.n.d.n.d.hr (beats / min)im1171 29180 23188 46178 31177 30176 29179 47177 38n.d.n.d.n.d.n.d.n.d.im2.5172 21178 29179 42161 31157 30155 35167 43207 44211 36218 34n.d.n.d.n.d.im5169 11191 25188 24185 15173 19172 14154 29171 29210 34 203 38179 25n.d.n.d.im10161 9200 17 194 9 175 5168 6161 7152 5142 8142 16192 36203 49 188 32192iv5160 13180 12167 11148 13137 11143 24152 43189 32216 33 185 12n.d.n.d.n.d.rr (breaths / min)im148 2180 2444 1433 1340 2738 2447 1978 59n.d.n.d.n.d.n.d.n.d.im2.564 3165 3033 7 28 7 28 11 27 15 22 4 27 8 31 9 46 16n.d.n.d.n.d.im557 1446 735 11 26 8 24 5 21 5 19 4 19 5 25 7 33 8 38 13n.d.n.d.im1055 1456 2727 14 21 9 18 6 17 5 16 4 14 5 19 14 30 25 29 9 30 8 32iv546 1117 2 21 2 19 3 19 3 17 3 21 9 22 8 33 12 40 9n.d.n.d.n.d.data are expessed as mean standard deviation. rt : rectal temperature, hr : heart rate, rr : respiratory rate. im1 : i m administration of 1 mg / kg alfaxalone, im2.5 : i m administration of 2.5 mg / kg alfaxalone, im5 : i m administration of 5 mg / kg alfaxalone, im10 : i m administration of 10 mg / kg alfaxalone, iv5 : iv administration of 5 mg / kg alfaxalone. the observation was completed at 45 min after the im1 treatment, at 90 min after the im2.5 and iv5 treatments, and at 120 min after the im5 treatments, because the cats recovered from the sedation and could walk up and down normally. significant difference from baseline value (p<0.05).. the rt significantly decreased from baseline at 20 min, at 30 min, at 45 min and at 15 min after the m2.5, im5, im10 and iv5 treatment, respectively. a mild hypothermia was detected in 4 cats (34.9 to 35.9c) from 90 to 150 min after the im10 treatment. a transient increase in hr from 2 to 5 min after the im10 treatment was observed. a transient increase in hr during the recovery period was also detected in the im5, im10 and iv5 treatments. in particular, clinically relevant hypotension (mabp < 60 mmhg) was observed in each one cat from 10 to 30 min after the im10 treatment (50 to 57 mmhg) and from 2 to 20 min after the iv5 treatment (55 to 58 mmhg). spontaneous breathing was maintained in all cats, but the rr significantly decreased from baseline after the im2.5, im5, im10 and iv5 treatments. the iv5 treatment produced a transient hypoxemia in 2 cats (spo2 87% and 88%) early after injection. im1 : i m administration of 1 mg / kg alfaxalone, im2.5 : i m administration of 2.5 mg / kg alfaxalone, im5 : i m administration of 5 mg / kg alfaxalone, im10 : i m administration of 10 mg / kg alfaxalone, iv5 : iv administration of 5 mg / kg alfaxalone. n.d. : not done. the observation was completed at 45 min after the im1 treatment, at 90 min after the im2.5 and iv5 treatments, and at 120 min after the im5 treatments, because the cats recovered from the sedation and could walk up and down normally. significant difference from baseline value (p<0.05). in the present study, the i m administration of alfaxalone - hpcd produced a dose - dependent sedation and immobilization with mild cardio - respiratory depression in healthy cats. the i m alfaxalone - hpcd at 10 mg / kg produced a similar degree, but longer lasting sedation and immobilization, compared to the i m alfaxalone - hpcd at 5 mg / kg. the i m alfaxalone - hpcd at 5 mg / kg produced a similar degree of sedation and immobilization to the iv alfaxalone - hpcd at 5 mg / kg. the duration of sedation, however, was longer lasting after the i m alfaxalone - hpcd at 5 mg / kg, compared to that after the iv alfaxalone - hpcd at 5 mg / kg. during recovery, tremors, ataxia, opisthotonus - like posture and transient paddling were observed in cats administered i m or iv alfaxalone - hpcd. one cat vomited during recovery from the i m alfaxalone - hpcd at 10 mg / kg. based on the dosing recommendations from the product information sheet, an i m administration of alfaxalone - hpcd (10 mg / kg) is expected to induce deep sedation or light anesthesia. thus, we chose four increasing i m doses of alfaxalone - hpcd up to 10 mg / kg in the present study. some cats vocalized during the i m administration of alfaxalone - hpcd, but there was no significant difference in the incidence of vocalization between the i m treatments. in the iv5 treatment, alfaxalone - hpcd has a neutral ph and does not cause pain and tissue irritation after iv administration or perivascular injection. in addition, grubb. mentioned that the i m alfaxalone - hpcd at 10 mg / kg seemed to cause moderate to profound discomfort in cats because of its excessive injection volume (1 ml / kg). therefore, we propose that the discomfort observed in the study was a volume associated effect and not a property of the alfaxalone - hpcd formulation itself. actually, there was no swelling, redness or changes in the skin observed around the site of injection during and after the experiment. the european federation of pharmaceutical industries associations and the european centre for the validation of alternative methods provide a guideline for the administration i m volumes. the reported i m volume considered as good practice is 0.25 ml / kg and the maximal dose volume is 0.5 ml / kg in the guideline, although there is no description for dose volume in cats. according to this guideline, the i m alfaxalone - hpcd dose considered as good practice is 2.5 mg / kg, and the maximal dose is 5 mg / kg based on the concentration of alfaxalone in the approved product (10 mg / ml). we considered that the im10 treatment was not a practical volume because the im10 treatment (1 ml / kg of the approved alfaxalone - hpcd product) produced discomfort during injection and required longer duration of i m administration. the development of a more concentrated alfaxalone - hpcd product is desirable in order to reduce the discomfort associated with large i m injection volumes and promote practical convenience. the objective of the present study was to investigate the sedative effects of i m alfaxalone - hpcd in cats without any other medicants. therefore, we adopted the experimental design that had the least amount of nociceptive stimulation (i.e. manipulations) during the assessment of sedation effect and the cardio - respiratory variables. for similar reasons, we did not perform tracheal intubation during the experiment. we adopted the composite measure scoring system for the evaluation of sedative or anesthetic effect. the scoring system was modified from the existing scoring system used for evaluating sedative and analgesic effects of medetomidine in dogs that consisted of 6 categories (spontaneous posture, placement on side, response to noise, jaw relaxation, general attitude and nociceptive response to interdigital pad pinch). these categories seemed to be suitable for the evaluation of the extent of sedation in cats, however, it was also anticipated that nociceptive stimulation would have some influence on the evaluation of sedative effect produced by alfaxalone - hpcd because of its poor analgesic property. therefore, we modified the existing scoring system by removing the category of nociceptive response to interdigital pad pinch. in the present study, the i m administration of alfaxalone - hpcd at 2.5, 5 and 10 mg / kg produced a clinically relevant sedative effect the i m alfaxalone - hpcd at 1 mg / kg did not provide reliable sedation for handling in healthy cats. the sedative scores after the im5 and im10 treatments were higher than that after the im2.5 treatment. in addition, the times to first appearance of spontaneous movement and durations of lack of spontaneous movement were markedly longer in the im10 treatment, compared to the im2.5 and im5 treatments. muir. reported that iv alfaxalone - hpcd produced a dose - dependent unresponsiveness in cats. the observations in the present study show that i m alfaxalone - hpcd produced a dose - dependent sedative effect in cats. the i m alfaxalone - hpcd at higher dose (5 and 10 mg / kg) produced a marked and prolonged sedation and immobilization in cats. an i m dose of alfaxalone - hpcd at 2.5 mg / kg may provide enough sedation for securing vascular access in healthy cats. the iv administration of alfaxalone - hpcd at 5 mg / kg is a recommended dose for anesthetic induction in cats [23, 30 ]. whittem. reported that all the 8 cats receiving 5 mg / kg of iv alfaxalone - hpcd became anesthetized shortly after the start of injection and the times to first head lift, and the times to unaided standing were 45 and 69 min, respectively. these findings are consistent with our results in the cats administered the iv5 treatment. in the present study, the im5 and im10 treatments produced slower onset, but achieved a maximum sedation score (score 16) in all cats equivalent to the iv5 treatment. it is possible that i m alfaxalone - hpcd at 5 or 10 mg / kg may achieve anesthetic induction as well as reliable sedation in cats. further investigation including an examination of the degree of difficulty in tracheal intubation will be necessary to determine the proper i m anesthetic induction doses of alfaxalone - hpcd in cats. it has been reported that an iv administration of alfaxalone - hpcd resulted in uneventful recovery in dogs [2, 22 ] and cats [23, 29 ]. on the other hand, it has also been reported that the iv alfaxalone - hpcd produced a poor quality of recovery in dogs and cats [20, 33 ]. reported that twitching, paddling, face rubbing, opisthotonus and tremors during recovery were observed in cats receiving iv alfaxalone - hpcd or propofol. it has also been reported that an iv alfaxalone - hpcd induction was associated with more episodes of paddling and trembling during recovery, compared to the propofol induction. these results may be related to the differences in drug clearance and the proportion of occupied gabaa receptor between alfaxalone and propofol. abnormal behavior including ataxia, increased motor activity, hyperreflexia, sensitivity to touch and violent recovery may also occur during the recovery from ketamine anesthesia, and these reactions are probably attributable to depression of the inferior colliculus and medial geniculate nucleus leading to misperception of auditory and visual stimuli. in the present study, almost the cats receiving the i m treatment at 2.5 to 10 mg / kg or the iv treatment at 5 mg / kg of alfaxalone - hpcd on its own exhibited tremors, ataxia and opisthotonus - like posture during the earlier period of recovery, but no cat was excited and behaved aggressively. on the other hand, less frequency of ataxia and tremors during recovery was observed after the i m treatment of alfaxalone - hpcd at 1 mg / kg. in addition, the i m alfaxalone - hpcd at the highest dose (10 mg / kg) was associated with paddling and vomiting. further studies are needed to clarify whether the perceived adverse effects during recovery are regarded as a direct side effect of alfaxalone - hpcd or not. the incidences of these episodes during recovery in the present study were higher than those in previous studies [20, 33 ]. reported that twitching, paddling, face rubbing, opisthotonus and tremors were observed during recovery from anesthesia in 14.3, 21.3, 4.3, 12.8 and 21.3% of 47 client owned cats receiving iv alfaxalone - hpcd for induction of anesthesia, respectively. in that study, all the cats were premedicated with acepromazine (0.05 mg / kg i m) and buprenorphine (0.01 mg / kg i m) before the iv alfaxalone - hpcd induction. zaki. showed that premedication (acepromazine 0.03 mg / kg and butorphanol 0.3 mg / kg administered subcutaneously) improved the quality of recovery after the iv alfaxalone - hpcd induction. similarly, it was reported that the quality of recovery from anesthesia with alfaxalone - hpcd was superior in cats premedicated with acepromazine or medetomidine compared to those in cats without premedication. these findings indicate that premedication with sedative and analgesic drugs would improve the quality of recovery from alfaxalone - hpcd in cats. in contrast, grubb. reported that premedication with dexmedetomidine (0.01 mg / kg i m) or dexmedetomidine plus hydromorphone (0.1 mg / kg i m) did not improve the quality of recovery from the i m alfaxalone - hpcd (5 mg / kg) and mentioned that the sedative effect of dexmedetomidine might have dissipated before the recovery period. further studies will be necessary to determine the influence of premedication on the quality of recovery from the i m alfaxalone - hpcd in cats. muir. reported that iv administration of alfaxalone - hpcd produced dose - dependent cardio - respiratory depression and an iv dose of 5 mg / kg produced hypoxia associated with hypoventilation mainly caused by decreases in respiratory rate and a transient apnea in cats. these findings are consistent with our results in the cats receiving the iv5 treatment. in the present study, spontaneous breathing was maintained, but the rr decreased in all the cats receiving the im2.5, im5, im10 and iv5 treatments. the cardio - respiratory changes were within normal ranges in all the cats receiving the im1, im2.5 and im5 treatments. the i m alfaxalone - hpcd at the highest dose (10 mg / kg) produced clinically relevant hypotension in one cat. these findings suggest that the i m administration of alfaxalone - hpcd produces a mild dose - dependent cardio - respiratory depression which is not clinically relevant up to doses of 5 mg / kg. however, there was a limitation in the present study, because we adopted indirect methods to measure cardio - respiratory valuables in order to achieve less nociceptive stimulation. in cats, the oscillometric method may result in an underestimation of the arterial blood pressure compared with the direct arterial blood pressure measurement [12, 25 ]. tremors during the recovery phase may affect the accuracy of the arterial blood pressure measured by the oscillometric method. in addition, inadequate light transmission and animal movement are the greatest limitations of spo2 measurement. we applied the spo2 sensor to the tongue during the lack of spontaneous movement and changed periodically. further sophisticated cardiorespiratory measurement including arterial blood gas analysis and measurement of cardiac output or tidal volume will be required to confirm the cardiopulmonary depression produced by the i m alfaxalone - hpcd in cats. in conclusion, i m alfaxalone - hpcd at doses of 2.5, 5 and 10 mg / kg produced dose - dependent sedation and immobilization in cats. the 10 mg / kg dose rate produced a similar degree of sedation, but longer lasting sedation compared to the i m alfaxalone - hpcd at 5 mg / kg. i m alfaxalone - hpcd caused a mild dose - dependent cardio - respiratory depression at doses up to 5 mg / kg. at 10 mg / kg, i m alfaxalone - hpcd caused clinical hypotension in one cat and was associated with vomiting in another cat. some cats vocalized during the i m administration of alfaxalone - hpcd, however, it was thought that the vocalization was related to the act of administering an i m injection and not a pain response. during the early recovery period, undesirable effects including tremors, ataxia and opisthotonus - like posture were associated with i m alfaxalone - hpcd at 2.5 to 10 mg / kg. nevertheless, we do not recommend the i m alfaxalone - hpcd at 10 mg / kg, because of the excessive i m volume (1 ml / kg). premedication with sedatives and/or analgesics should be a focus of future investigations in order to reduce the injection volume of i m alfaxalone - hpcd and improve the quality of recovery. | the sedative effects of intramuscular (i m) alfaxalone in 2-hydroxypropyl - beta - cyclodextrin (alfaxalone - hpcd) were evaluated in cats. the cats were treated with alfaxalone - hpcd in five occasions with a minimum 14-day interval between treatments : an i m injection of 1.0 mg / kg (im1), 2.5 mg / kg (im2.5), 5 mg / kg (im5) or 10 mg / kg (im10), or an intravenous injection of 5 mg / kg (iv5). the sedative effects were evaluated subjectively using a composite measurement scoring system (a maximum score of 16). cardio - respiratory variables were measured non - invasively. the median sedation scores peaked at 10 min (score 9), 15 min (score 14), 10 min (score 16), 10 to 20 min (score 16) and 2 to 5 min (score 16) after the im1, im2.5, im5, im10 and iv5 treatments, respectively. the im5 treatment produced longer lasting sedation, compared to the iv5 treatment. durations of maintenance of lateral recumbency after the im10 treatment (115 22 min) were longer than those after the im2.5 (40 15 min), im5 (76 21 min) and iv5 treatments (50 5 min). cardio - respiratory variables remained within clinically acceptable ranges, except for each one cat that showed hypotension (< 60 mmhg) after the im10 and iv5 treatments. tremors, ataxia and opisthotonus - like posture were observed during the early recovery period after the im2.5, im5, im10 and iv5 treatments. in conclusion, i m alfaxalone - hpcd produced dose - dependent and clinically relevant sedative effect at 2.5 to 10 mg / kg in healthy cats. hypotension may occur at higher i m doses of alfaxalone - hpcd. |
in the netherlands, the debate about immigration and integration has hardened over the years, even more so than in other european countries. much of the debate focuses on muslim minorities, who are perceived as a single group despite their highly diverse ethnic background. the building of mosques, the use of religious symbols such as the headscarf, gender inequality, anti - integration pronouncements by ultra - orthodox imams, and islam - inspired political extremism are all popular subjects in the media (e.g. uitermark. in addition to a change in views about islam in the western world, an impetus for the negative climate was the brutal murder of film director and media personality theo van gogh by mohammed b., son of moroccan migrants in november 2004 (see buruma 2006). during the first months after the murder, radicalized youngsters made the headlines of the (internet) press on an almost daily basis. this does not mean, however, that the threat of radicalization amongst muslim youngsters has diminished or that the soil for terrorism has become less fertile, for a negative attitude against islam is still highly prevalent. the openly islamophobic freedom party of geert wilders had a landslide victory in the 2010 elections, becoming the third largest party. a trend study about polarization and radicalization in 2009 also concludes that there is a growing number of interethnic confrontations and an increase in tensions and confrontations with an islamophobic nature. this is not only true for extreme right youths, but also for the average dutch youngsters (moors. although the majority of citizens believe that polarization is a bigger problem than radicalization, they do relate the increase in opposing positions to immigrants, muslims especially (moors. it is clear that in this environment the relation of muslim youngsters to the dutch society is under pressure (e.g. pels 2003) ; what is more, these developments can contribute to an increased attachment of youngsters to islam. a research of entzinger and dourleijn (2008) in rotterdam for instance shows that amongst moroccan youngsters, scoring lowest on the ethnic hierarchy in the netherlands (hagendoorn 2007) and feeling more often rejected than other migrant groups (moors. 2009), the number of practicing muslims increases. a growing number is willing to participate in legal activities like demonstrations to show their aggravation. many youngsters experience a wall of distrust, which for some of them means that they no longer take an interest in their environment and its rules and eventually live up to the negative expectations that others have against them (see also harris 1995). the upraise of the populist parties with right - wing populist political messages may not only be a risk for the radicalization of muslim youngsters, but may also infuse right - wing extremism, because right - wing convictions are openly preached. the fact that right - wing views are no longer politically incorrect may be a stepping stone to extremist views. although the future may also show that the increasing political power of people with these convictions reduces the likelihood that they will become extremists, the current dutch society seems to face a looming danger on two sides. moreover, it is well possible that the growth of right - wing extremism and islamic radicalism reinforce each other. thus, we suggest that research into prevention of radicalization is still imperative, but more importantly, we want to argue that it requires an additional focus, namely on the socialization and educational environments within which children and youngsters develop. while there is a growing research interest into the socio - psychological antecedents of radicalization (e.g. moghaddam 2005 ; van den bos. 2009), there is not much insight into the relation between socialization, education and radicalization. available facts, however, provide us with sufficient indications that this knowledge gap needs to be closed. radicalization is more prevalent amongst adolescents and young adults (1530 years) and trends show that youngsters radicalize at a younger age (buijs. 2006 ; sageman 2008 ; slootman and tillie 2006).1 moreover, the developmental tasks of adolescents among which are developing a personal, social and political identity, redefining bonds and relations and forming new relationships this is particularly the case when for instance (perceived) exclusion and personal or group threat, being uprooted and/or an experienced gap with the adult world lie at the root of this vulnerability (buijs. a vigilant attitude by institutions responsible for children s socialization and education, especially families and schools, toward nascent radicalization seems to be in place (e.g. hagan. we describe our theoretical presumptions with regard to the relation between two central aspects of parenting and school education on the one hand and radicalization on the other hand. next, we present insights from an analysis of existing empirical research, for which we mainly draw from three european countries in which upbringing in muslim families and by parents with right - wing sympathies have been investigated most extensively. however, although the research is drawn from these countries, our claim that research about radicalization needs to include the education and socialization of youngsters, is not specific to those countries. moreover, we suggest that researchers in all western societies should investigate important educational influences on phenomena of polarization and radicalization, also in order to enable the development of preventive measures. for this reason in addition to a call for further research, our article ends with the suggestion that assistance to parents and schools that diminishes the development of radicalization has to be developed. radical does not necessarily have a negative meaning. as the dictionary teaches us, the first, and non - pejorative meaning of being radical is arising from or going to a root or to the basis. an example of a radical person, in this sense of the word, is someone who wants to change the domination and pollution of the consumer market and advocates that all consumer products of multi - nationals be banned and that only local produce should be sold. this is, however, not the dominant meaning, which is departing markedly from the existing or being extreme. although close to our example, this meaning has a negative connotation, which is related to the phrase being extreme. in this definition, the difference between radicalism and extremism seems to evaporate. both concepts are being used for the same type of conviction and disposition, at least for radicalism in the negative sense and this has become the dominant conception of radicalism (mandel in press). however, although the terms are used for the same type of convictions and dispositions, they tend to refer to different groups. while academic literature on extremism in recent years also covers radicalized muslims, radicalism on the other hand almost exclusively stands for the views of islamist fundamentalists who use illegal and/or immoral means to spread their beliefs or found their utopian state (see for instance schmid and price 2011). it should also be noted that in current academic and popular literature the difference between radicalism and terrorism has become a very thin line. while some radicalized persons and right wing extremists may not shy away from terrorist acts, others may use less extreme ways to impose their views on other people. we follow mandel (in press) who proposes as a working definition of radicalization : an increase in and/or reinforcing of extremism in the thinking, sentiments, and/or behavior of individuals and/or groups of individuals (p. 20). research into right - wing and muslim radicalism seems to indicate that there are similar socialization and developmental patterns. for instance, in both cases feelings of unjust treatment and of insecurity and perceived fraternal deprivation can lead to the development of radical beliefs and acts (reinares. we already noted in the introduction that the debate in the netherlands about islam and muslims has become quite extreme. proposals by wilders party for freedom to put a tax on the wearing of scarves (which he malignly calls the head rag tax) or wilders reference to muslim voters as voting cattle are telling examples. in such a hostile environment we may expect a rise in feelings of relative deprivation,2 (perceived) injustice and group threat (e.g. moghaddam 2005 ; silke 2008 ; van den bos. 2009), which can lead to feelings of uncertainty (e.g. hogg 2004 ; moghaddam 2005). this, in turn can motivate people to finding other securities, and the clear rules and distinct groups of radicalized peers are then attractive alternatives. various empirical studies indeed show that there is a relation between real and perceived deprivation, feelings of powerlessness and low self - esteem on the one hand and radicalization on the other hand (buijs. 2006 ; kuhn 2004). young muslims in the netherlands have a high risk to experience these threats to their self. in addition to their (perceived) exclusion for being a migrant or muslim adverse living conditions may also take their toll. the majority grows up in ethnically diverse neighborhoods in which there is an accumulation of problems : poverty, school failure, health and behavioral problems, unemployment, disruptive behavior and criminality (e.g. pels. moreover, possibilities for collective socialization in the neighborhood are being challenged (for instance leventhal and brooks - gunn 2000). for native youngsters who feel or are deprived of opportunities, the strong and relatively simple right - wing message in the netherlands, native youth in rural areas clash with immigrant youth out of frustration about (perceived) negative interethnic relations, interethnic competition and the loss of their imagined community due to the rapid influx of migrants during the past decennia (cadat and engbersen 2006 ; van der valk and wagenaar 2010). researchers, however, also agree that radicals, extremists, and terrorists have different backgrounds and that there is not a specific or special factor that all persons share in their personality or history (see for instance silke 2008), although some do suggest that there are general phases or steps in the process of radicalization (bandura 2004 ; moghaddam 2005 ; porter and kebbell 2011). when researchers investigate determinants (see for an overview silke 2008), they tend to look at characteristics of the individual (biological, psychological), at environment or context, and at interactions between these two (2008), for instance, state that the commonality between all forms of radicalization leading towards violence isthat it always takes place at the intersection of an enabling environment and a personal trajectory. not all individuals who share the same sense of injustice or are living in the same polarized environment turn to radicalism and even less to violence and terrorism. concrete personal experiences, kinship and friendship, group dynamics and socialization into the use of violence are needed to trigger the actual process. (p. 9).we want to add that parents and teachers are well placed to influence children and youngsters, both towards radicalization as well as to the prevention of this process. that it always takes place at the intersection of an enabling environment and a personal trajectory. not all individuals who share the same sense of injustice or are living in the same polarized environment turn to radicalism and even less to violence and terrorism. concrete personal experiences, kinship and friendship, group dynamics and socialization into the use of violence are needed to trigger the actual process. empirical research has indicated that the level of education of radicalized youngsters and adults does not have a strong influence on (prevention) of radicalization (see for instance silke 2008). among radicalized persons, one can find well - educated persons as well as those without a diploma. for instance, where radicalization and particularly terrorism receive a lot of scientific and political attention, education is hardly included in an attempt to counter radicalization (see webber 2011). however, the education youngsters receive from their parents and in schools includes much more than academic level. we believe that it is important to pay attention to two aspects of education in families and schools, namely the content of the education youngsters receive as well as the style with which parents and teachers raise and educate children and youngsters. for both aspects, the content (aims and ideals) of the upbringing and education of parents and teachersit is theoretically plausible to presume that parents and teachers who have radicalized or extremist convictions aim to transmit these ideals and values to the children they are responsible for. for, if one is convinced of the (moral or religious) truth of one s ideals and values, one will want to ensure that children will also be as strongly convinced. all fundamentalist, radicalized and extremist educators share the propensity to indoctrinate. whether or not they are successful is obviously a different matter. however, we may assume that children will be influenced by the ideal - driven education they receive and that there is a likelihood that children come to adopt these ideals.in contrast, it is reasonable to assume that youngsters will adopt democratic ideals if they are fostered by educators. since dewey (1903), many educationalists have suggested that the development of children into democratic citizens is furthered if they are raised in democratic schools. if parents and teachers aim to educate children towards democratic citizens who have respect for the rights of others and to tolerate beliefs, religious or otherwise, that are different from their own (see for instance davies 2009 ; webber 2011), the education that children and youngsters receive cultivates beliefs and dispositions that oppose radicalism and extremism.more particularly, we may assume on theoretical grounds that moral education can prevent radicalization. bandura (2002, 2004) suggests that moral disengagement might play an important role in this process. under the umbrella of disengagement, he describes several mechanisms, such as redefining harmful conduct by moral justification, euphemistic labeling of acts, minimizing or misconstruing the consequences, dehumanization of the other or attribution of blame on the victim. democratic moral education may have an important role in adequately responding to signs of moral distancing.the style of parenting or teachingthe authoritarian style of education is characterized by demanding strict obedience and by a lack of explanation or justification of the rules children and youngsters are expected to follow (see baumrind 1966). such a style will not contribute to the development of critical thinking and negotiation and therefore does not diminish the chance of radicalization. equally, lack of openness to discuss views does not further the openness to others.it seems reasonable to assume that there is a positive relation between an authoritative educational style and democratic attitude of children which may have a preventive influence on the development of radicalization. if parents are open to a discussion with their children, if they give their reasons for their beliefs and decisions and if they allow children to negotiate (which does not mean that children have a say in everything), they further a democratic attitude in their children. for instance, authoritative muslim parents may be able to enhance the development of what is called polder islam : a type of faith that corresponds with the discussion and coalition culture in the netherlands (buitelaar 2009). equally, we suggest that there are good reasons to presume that inclusive approaches in multi - ethnic schools, like creating a sense of community through cooperative learning and developing democratic and justice - oriented communities (e.g. hansen 2001 ; westheimer and kahne 2004), instead of accentuating assimilation and control, has a diminishing effect on the onset of radicalization.of course, the style of education in itself is not sufficient but should be complemented with an appropriate content. it is, for instance, possible that parents with an authoritative parenting style have racist ideals or believe that their ethnic or religious identity is being threatened, which they also pass onto their children. it is therefore important to make a clear distinction between educational aims or ideals on the one hand and the style of education on the other hand. the content (aims and ideals) of the upbringing and education of parents and teachersit is theoretically plausible to presume that parents and teachers who have radicalized or extremist convictions aim to transmit these ideals and values to the children they are responsible for. for, if one is convinced of the (moral or religious) truth of one s ideals and values, one will want to ensure that children will also be as strongly convinced. all fundamentalist, radicalized and extremist educators share the propensity to indoctrinate. whether or not they are successful is obviously a different matter. however, we may assume that children will be influenced by the ideal - driven education they receive and that there is a likelihood that children come to adopt these ideals.in contrast, it is reasonable to assume that youngsters will adopt democratic ideals if they are fostered by educators. since dewey (1903), many educationalists have suggested that the development of children into democratic citizens is furthered if they are raised in democratic schools. if parents and teachers aim to educate children towards democratic citizens who have respect for the rights of others and to tolerate beliefs, religious or otherwise, that are different from their own (see for instance davies 2009 ; webber 2011), the education that children and youngsters receive cultivates beliefs and dispositions that oppose radicalism and extremism.more particularly, we may assume on theoretical grounds that moral education can prevent radicalization. bandura (2002, 2004) suggests that moral disengagement might play an important role in this process. under the umbrella of disengagement, he describes several mechanisms, such as redefining harmful conduct by moral justification, euphemistic labeling of acts, minimizing or misconstruing the consequences, dehumanization of the other or attribution of blame on the victim. democratic moral education may have an important role in adequately responding to signs of moral distancing.the style of parenting or teachingthe authoritarian style of education is characterized by demanding strict obedience and by a lack of explanation or justification of the rules children and youngsters are expected to follow (see baumrind 1966). such a style will not contribute to the development of critical thinking and negotiation and therefore does not diminish the chance of radicalization. equally, lack of openness to discuss views does not further the openness to others.it seems reasonable to assume that there is a positive relation between an authoritative educational style and democratic attitude of children which may have a preventive influence on the development of radicalization. if parents are open to a discussion with their children, if they give their reasons for their beliefs and decisions and if they allow children to negotiate (which does not mean that children have a say in everything), they further a democratic attitude in their children. for instance, authoritative muslim parents may be able to enhance the development of what is called polder islam : a type of faith that corresponds with the discussion and coalition culture in the netherlands (buitelaar 2009). equally, we suggest that there are good reasons to presume that inclusive approaches in multi - ethnic schools, like creating a sense of community through cooperative learning and developing democratic and justice - oriented communities (e.g. hansen 2001 ; westheimer and kahne 2004), instead of accentuating assimilation and control, has a diminishing effect on the onset of radicalization.of course, the style of education in itself is not sufficient but should be complemented with an appropriate content. it is, for instance, possible that parents with an authoritative parenting style have racist ideals or believe that their ethnic or religious identity is being threatened, which they also pass onto their children. it is therefore important to make a clear distinction between educational aims or ideals on the one hand and the style of education on the other hand. it is theoretically plausible to presume that parents and teachers who have radicalized or extremist convictions aim to transmit these ideals and values to the children they are responsible for. for, if one is convinced of the (moral or religious) truth of one s ideals and values, one will want to ensure that children will also be as strongly convinced. all fundamentalist, radicalized and extremist educators share the propensity to indoctrinate. whether or not they are successful is obviously a different matter however, we may assume that children will be influenced by the ideal - driven education they receive and that there is a likelihood that children come to adopt these ideals. in contrast, it is reasonable to assume that youngsters will adopt democratic ideals if they are fostered by educators. since dewey (1903), many educationalists have suggested that the development of children into democratic citizens is furthered if they are raised in democratic schools. if parents and teachers aim to educate children towards democratic citizens who have respect for the rights of others and to tolerate beliefs, religious or otherwise, that are different from their own (see for instance davies 2009 ; webber 2011), the education that children and youngsters receive cultivates beliefs and dispositions that oppose radicalism and extremism. more particularly, we may assume on theoretical grounds that moral education can prevent radicalization. bandura (2002, 2004) suggests that moral disengagement might play an important role in this process. under the umbrella of disengagement, he describes several mechanisms, such as redefining harmful conduct by moral justification, euphemistic labeling of acts, minimizing or misconstruing the consequences, dehumanization of the other or attribution of blame on the victim. democratic moral education may have an important role in adequately responding to signs of moral distancing. the style of parenting or teaching the authoritarian style of education is characterized by demanding strict obedience and by a lack of explanation or justification of the rules children and youngsters are expected to follow (see baumrind 1966). such a style will not contribute to the development of critical thinking and negotiation and therefore does not diminish the chance of radicalization. equally, lack of openness to discuss views does not further the openness to others. it seems reasonable to assume that there is a positive relation between an authoritative educational style and democratic attitude of children which may have a preventive influence on the development of radicalization. if parents are open to a discussion with their children, if they give their reasons for their beliefs and decisions and if they allow children to negotiate (which does not mean that children have a say in everything), they further a democratic attitude in their children. for instance, authoritative muslim parents may be able to enhance the development of what is called polder islam : a type of faith that corresponds with the discussion and coalition culture in the netherlands (buitelaar 2009). equally, we suggest that there are good reasons to presume that inclusive approaches in multi - ethnic schools, like creating a sense of community through cooperative learning and developing democratic and justice - oriented communities (e.g. hansen 2001 ; westheimer and kahne 2004), instead of accentuating assimilation and control, has a diminishing effect on the onset of radicalization. of course, the style of education in itself is not sufficient but should be complemented with an appropriate content. it is, for instance, possible that parents with an authoritative parenting style have racist ideals or believe that their ethnic or religious identity is being threatened, which they also pass onto their children. it is therefore important to make a clear distinction between educational aims or ideals on the one hand and the style of education on the other hand. we have analyzed theoretical and empirical studies about upbringing in muslim families and the content and style of education of parents with (extreme) right - wing sympathies in relation to radicalization of their adolescent children. as mentioned, there is hardly any research about this relationship (see for instance schmid and price 2011), particularly in the case of muslim youngsters, and therefore we also use more general empirical research about these youngsters and those with latent right - wing sympathies to see if they are socialized in an environment that makes them more or less prone to radicalize. empirical studies about muslim families were mainly drawn from the netherlands where a lot of empirical research has been conducted with regard to the socialization and educational situation of muslim youngsters. thus, insights from research within the dutch context, which has specific challenges for both categories of youngsters, will be used as prime examples of existent knowledge. empirical research into the socialization history of youth with right - wing sympathies is scarce in the netherlands. therefore, our main sources of information about this group will be from other countries, germany and belgium in particular. research of zenter and renaud (2007) that specifically looked at the similarity of ideals within families shows that the similarity is mainly due to the culture of the environment in which the family lives. after correcting for cultural factors, the similarity between the ideal selves of parents and children is low, due to what they call a telephone game effect. the message [ideals of the parents, inserted by authors ] is altered because not everything that parents wish for themselves do they also wish for their children. subsequently, the message is altered again because the latter perceive what parents wish for their children with imperfect accuracy. a final transmutation of the message occurs because parental ideals, even if accurately perceived, are not always accepted by the child. parents with right - wing extremist sympathies and muslim parents may have a stronger wish to pass on their ideals and values to their children, particularly because their views differ from those of the mainstream culture. indeed, research of boehnke. (2007) showed that the distance of the family from what they call zeitgeist affects intra - familial value similarity. it can also be suggested that if the family culture differs from the mainstream culture, which is the case in the majority of muslim migrant families and of right wing native families, intergenerational similarity of ideals and values can be attributed to the influence of parents. (2008) for instance found that in immigrant groups the ethnic zeitgeist played a significant role in adolescents acceptance of family obligations. the message [ideals of the parents, inserted by authors ] is altered because not everything that parents wish for themselves do they also wish for their children. subsequently, the message is altered again because the latter perceive what parents wish for their children with imperfect accuracy. a final transmutation of the message occurs because parental ideals, even if accurately perceived, are not always accepted by the child. empirical research that particularly focuses on the influence of parental ideals and aims on the onset of radicalization of muslim youngsters is, however, not prevalent. anglo - saxon literature mentions different strategies of ethnic (or racial) socialization in the family (e.g. hughes. 2006), with two poles that can concisely be described as follows : parents can use more open or dual parenting strategies, in which ethno - cultural loyalty coincides with openness towards the other (e.g. lafromboise. 1993), or more defensive or antagonistic coping styles that may inculcate an attitude of distrust in their children and may make them more prone to conflict vis - - vis the qualitative research on parenting in dutch minority families points to more or less defensive or antagonistic attitudes vis - - vis society at large. particularly muslim parents of the first generation transfer a certain distrust towards their environment (pels. 2009), but there is insufficient knowledge about the influence of this distrust on youngsters. nor do we know how parents respond to children who are under the influence of radical islamists, or how radicalization influences family relations. in contrast, there is empirical research about the similarity of right - wing convictions between parents and children. research examining similarity in xenophobia between parents and pre - adolescent children yields mixed results, but studies among adolescents point to a significant concordance (gniewosz and noack 2006). duriez, soenens and vansteenkiste (2007) discovered that parental goals do predict right - wing authoritarianism and social dominance orientation and duriez and soenens research (2009) corroborated the conclusion of a few studies among adolescents that there is a significant concordance in racism between parents and their adolescent children, which in their study was found to result largely from a more fundamental intergenerational transmission of ideology german studies examining anti - foreigner and national - authoritarian attitudes also found similarities between parents and their adolescent children (kracke. 1993 ; noack and kracke 2000), indicating processes of role modeling in the area of right wing extremism. whether or not this is true for migrant families whose culture also differs from the mainstream culture is an important empirical question. there is also empirical research available about the influence of parenting styles and right - wing extremism in youngsters. higher scores of adolescents on xenophobia, as one indicator of right - wing extremism, were found in families characterized by lower emotional relatedness (kracke. a more punitive and authoritarian - rigid parenting style has been associated with more right - wing attitudes (fend 1991), more xenophobia (hefler. 1999), and stronger authoritarian characteristics (rebenstorf. 2000) in adolescents. altogether, we conclude that, besides the direct influences of parents as role - models, parental style as indicated by poor emotional relationships and communication and by authoritarian parenting may play a significant role in the socialization of deviant political behavior. there is no similar empirical research available with regard to the relation between radicalization amongst muslim youngsters and the parenting style of parents. however, empirical research does show that the parenting style of muslim parents may not have an inhibiting effect on radicalization. muslim parents in the netherlands rank conformity and moral obeisance higher and autonomy lower as parental goals compared to native dutch parents, though much of this difference diminishes when educational level is taken into account (pels and de haan 2007 ; pels. qualitative data, however, point to differences in meaning attached to the same goals. the muslim parents interpret autonomy in a less individualistic sense and conformity in a less egalitarian sense than dutch parents. authoritative control is fairly common within dutch families, whereas restrictive control is more salient within minority families, who use both types of controlling techniques to about the same extent. maintaining authority and communication with their children in a culture of egalitarian social interaction is perceived by them as a more difficult task (pels. youngsters in these circles also perceive a lack of open communication with their parents (e.g. pels 2003 ; pels. firstly, it has been shown that in general children risk being marginalized when they are raised in a cold family in which there are also conflicts about authority (e.g. patterson and yoerger 2002 ; pels 2003 ; stevens. 2007). research amongst moroccan families shows that this is particularly true for boys : they can not turn to their parents as easily as girls, which means that they are more dependent on their peers (de jong 2007 ; pels and de haan 2007 ; stevens. 2004). girls are educated in a stricter way ; for them islam can be a way to strive for autonomy and freedom (pels. schools are in principle a good place for youngsters from different ethnic backgrounds to bridge the ethnic boundaries. schools are one of the contexts where peers meet, informally but also in task - oriented settings. furthermore, these groups can provide the social skills that may enhance other relationships (okoon 1997). research, however, indicates that we should not be too optimistic in our expectations. interethnic contacts in schools do not significantly increase (bakker. 2007). moreover, youngsters tend to withdraw into their own ethnic groups outside the school context (interculturele verhoudingen op amsterdamse scholen, 2005). in general, research on the contact - hypothesis (increased interethnic contact leads to a decrease of prejudice and an increase of interaction across ethnic borders) shows that this hypothesis is not corroborated on a wide scale. contact leads to positive interactions only in specific contexts, for instance if groups are equal in their position on the status hierarchy (lindo 2008). we have not found empirical research that focuses on the similarity between radical ideals and values of teachers and pupils. empirical research into the influence of democratic ideals and moral values of teachers and schools on pupils and thereby the decrease of radicalization is similarly hard to find. there is some evidence that teachers interventions with xenophobic utterances of pupils are negatively related to xenophobia of pupils (bacher 2001). in other words, intervening matters. however, not all teachers seem to have great interest in the socialization of their pupils in this sense. as pels (2011) concludes on the basis of a review of dutch literature, a crystallized view on dealing with diversity on a religious, cultural or ethnic basis, or with tensions on these issues is still farfetched. research of the city of amsterdam (gemeente amsterdam 2005) among 25 schools for secondary education points to an increase in incidents between groups of pupils as well as between minority pupils and teachers. teachers interviewed by leeman (2003) report problems with teaching on politically laden subjects as the middle east, terrorist attacks or religion. not only the content of education is of importance, but also teaching competence and style. leeman (2003) found that teachers are at a loss finding ways to handle difficult discussions in which respect and consensus are difficult to reach. in order to ensure that lessons can continue orderly and to maintain a relatively peaceful atmosphere in the class, teachers tend to avoid topics that touch on religious and ethnic - cultural diversity. apart from the fact that teachers may lack competencies to effectively cope with tensions in the classroom, they may apply a more or less authoritarian style of approaching their pupils. as we argued, their educational style can also have a positive or negative influence on radicalization, just as we discussed for parents. interestingly, schools that provide vocational education where minority pupils are overrepresented tend to prefer authoritarian education instead of interactive or participative education (mooren 2006 ; onstenk 2006). again, this does not seem to be an effective style for developing democratic dispositions and acting. research in amsterdam (gemeente amsterdam 2005) shows that generally the commitment or loyalty of minority children to their school is greater if there is more individual attention for students. this last finding is corroborated in other research : young muslims mention the important support they felt from a single teacher who did take notice and interest (pels 2008 ; pels. this is an important fact, because youngsters who are susceptible to radicalization tend to have a strong need for acknowledgement and relationships (buijs. the literature, however, also mentions more or less conscious exclusion of pupils by teachers. exceptions is not uncommon (koole and hanson 2002). the negative influence of discrimination and different treatment of children from minority groups on their well - being at school or college, motivation and achievements is broadly documented (e.g. de graaf. 2006 ; dilworth and brown 2001 ; severiens. 2008 ; wubbels. since (perceived) deprivation is one of the major root causes for radicalization, we may conclude that current practices in schooling often do not seem apt to diminish the susceptibility to radicalization in youngsters. citizenship education might be one of the answers. in response to threats to democracy by a violent political islam and extremism from the right, and the resulting social instability and feelings of insecurity, many western countries have welcomed citizenship to their political and educational agenda (brubaker 2001). however, in many dutch schools citizenship education is taking a one - sided turn, accentuating individual rights and (moral) obligations and focusing on students of non - western descent to assimilate. it does not stimulate teachers and students to take a reflective stance on inequalities and cultural pluralism in society (leeman and pels 2006). finally, it may not only be the education within families or schools in itself that has an influence on the onset of radicalization, it is also possible that a lack of a good functioning (inter ethnic) civil society is an obstacle. we may presume that interaction and preferably co - operation between families and schools will have a diminishing effect on radicalization. particularly for youngsters who are vulnerable due to perceived discrimination and injustice in society and who are searching for an authority figure, the cooperation between these socializing institutions might be crucial. recently, there is a growing interest in collective socialization, which is an active engagement between and cooperation of informal and formal educators in the community. examples are a communal formulation of rules (intergenerational closure), exchange of information and advice and informal social control and support. these forms of social capital are not self - evident, on the contrary, one of the undermining factors is the presence of an ethnic heterogeneous population and concomitant language, social and cultural hurdles (sampson. available dutch research shows that the two educational domains we have highlighted are often separate islands that are unable to realize sufficient bridging. in practice cooperation between parents and schools often plods along heavily (pels 2011). on the contrary, both parties may even hinder or undermine each other s intentions. for example, research in amsterdam schools showed that parents and schools differed in the messages they provided about the murder of theo van gogh (visser and slot 2005) and another study among amsterdam schools showed that a wider gap between migrant parents and the school increases the distance between migrant and native youngsters (interculturele verhoudingen 2005). this could lead to an educational vacuum of which the signs are visible in the public domain in which groups of youngsters take a lead in their own socialization (pels 2003). research of zenter and renaud (2007) that specifically looked at the similarity of ideals within families shows that the similarity is mainly due to the culture of the environment in which the family lives. after correcting for cultural factors, the similarity between the ideal selves of parents and children is low, due to what they call a telephone game effect. the message [ideals of the parents, inserted by authors ] is altered because not everything that parents wish for themselves do they also wish for their children. subsequently, the message is altered again because the latter perceive what parents wish for their children with imperfect accuracy. a final transmutation of the message occurs because parental ideals, even if accurately perceived, are not always accepted by the child. parents with right - wing extremist sympathies and muslim parents may have a stronger wish to pass on their ideals and values to their children, particularly because their views differ from those of the mainstream culture. indeed, research of boehnke. (2007) showed that the distance of the family from what they call zeitgeist affects intra - familial value similarity. it can also be suggested that if the family culture differs from the mainstream culture, which is the case in the majority of muslim migrant families and of right wing native families, intergenerational similarity of ideals and values can be attributed to the influence of parents. (2008) for instance found that in immigrant groups the ethnic zeitgeist played a significant role in adolescents acceptance of family obligations. the message [ideals of the parents, inserted by authors ] is altered because not everything that parents wish for themselves do they also wish for their children. subsequently, the message is altered again because the latter perceive what parents wish for their children with imperfect accuracy. a final transmutation of the message occurs because parental ideals, even if accurately perceived, are not always accepted by the child. empirical research that particularly focuses on the influence of parental ideals and aims on the onset of radicalization of muslim youngsters is, however, not prevalent. anglo - saxon literature mentions different strategies of ethnic (or racial) socialization in the family (e.g. hughes. 2006), with two poles that can concisely be described as follows : parents can use more open or dual parenting strategies, in which ethno - cultural loyalty coincides with openness towards the other (e.g. lafromboise. 1993), or more defensive or antagonistic coping styles that may inculcate an attitude of distrust in their children and may make them more prone to conflict vis - - vis the qualitative research on parenting in dutch minority families points to more or less defensive or antagonistic attitudes vis - - vis society at large. particularly muslim parents of the first generation transfer a certain distrust towards their environment (pels. 2009), but there is insufficient knowledge about the influence of this distrust on youngsters. nor do we know how parents respond to children who are under the influence of radical islamists, or how radicalization influences family relations. in contrast, there is empirical research about the similarity of right - wing convictions between parents and children. research examining similarity in xenophobia between parents and pre - adolescent children yields mixed results, but studies among adolescents point to a significant concordance (gniewosz and noack 2006). duriez, soenens and vansteenkiste (2007) discovered that parental goals do predict right - wing authoritarianism and social dominance orientation and duriez and soenens research (2009) corroborated the conclusion of a few studies among adolescents that there is a significant concordance in racism between parents and their adolescent children, which in their study was found to result largely from a more fundamental intergenerational transmission of ideology german studies examining anti - foreigner and national - authoritarian attitudes also found similarities between parents and their adolescent children (kracke. 1993 ; noack and kracke 2000), indicating processes of role modeling in the area of right wing extremism. whether or not this is true for migrant families whose culture also differs from the mainstream culture is an important empirical question. there is also empirical research available about the influence of parenting styles and right - wing extremism in youngsters. higher scores of adolescents on xenophobia, as one indicator of right - wing extremism, were found in families characterized by lower emotional relatedness (kracke. a more punitive and authoritarian - rigid parenting style has been associated with more right - wing attitudes (fend 1991), more xenophobia (hefler. 1999), and stronger authoritarian characteristics (rebenstorf. 2000) in adolescents. altogether, we conclude that, besides the direct influences of parents as role - models, parental style as indicated by poor emotional relationships and communication and by authoritarian parenting may play a significant role in the socialization of deviant political behavior. there is no similar empirical research available with regard to the relation between radicalization amongst muslim youngsters and the parenting style of parents. however, empirical research does show that the parenting style of muslim parents may not have an inhibiting effect on radicalization. muslim parents in the netherlands rank conformity and moral obeisance higher and autonomy lower as parental goals compared to native dutch parents, though much of this difference diminishes when educational level is taken into account (pels and de haan 2007 ; pels. qualitative data, however, point to differences in meaning attached to the same goals. the muslim parents interpret autonomy in a less individualistic sense and conformity in a less egalitarian sense than dutch parents. authoritative control is fairly common within dutch families, whereas restrictive control is more salient within minority families, who use both types of controlling techniques to about the same extent. maintaining authority and communication with their children in a culture of egalitarian social interaction is perceived by them as a more difficult task (pels. youngsters in these circles also perceive a lack of open communication with their parents (e.g. pels 2003 ; pels. firstly, it has been shown that in general children risk being marginalized when they are raised in a cold family in which there are also conflicts about authority (e.g. patterson and yoerger 2002 ; pels 2003 ; stevens. 2007). research amongst moroccan families shows that this is particularly true for boys : they can not turn to their parents as easily as girls, which means that they are more dependent on their peers (de jong 2007 ; pels and de haan 2007 ; stevens. 2004). girls are educated in a stricter way ; for them islam can be a way to strive for autonomy and freedom (pels. schools are in principle a good place for youngsters from different ethnic backgrounds to bridge the ethnic boundaries. schools are one of the contexts where peers meet, informally but also in task - oriented settings. furthermore, these groups can provide the social skills that may enhance other relationships (okoon 1997). research, however, indicates that we should not be too optimistic in our expectations. interethnic contacts in schools do not significantly increase (bakker. 2007). moreover, youngsters tend to withdraw into their own ethnic groups outside the school context (interculturele verhoudingen op amsterdamse scholen, 2005). in general, research on the contact - hypothesis (increased interethnic contact leads to a decrease of prejudice and an increase of interaction across ethnic borders) shows that this hypothesis is not corroborated on a wide scale. contact leads to positive interactions only in specific contexts, for instance if groups are equal in their position on the status hierarchy (lindo 2008). we have not found empirical research that focuses on the similarity between radical ideals and values of teachers and pupils. empirical research into the influence of democratic ideals and moral values of teachers and schools on pupils and thereby the decrease of radicalization is similarly hard to find. there is some evidence that teachers interventions with xenophobic utterances of pupils are negatively related to xenophobia of pupils (bacher 2001). in other words, intervening matters. however, not all teachers seem to have great interest in the socialization of their pupils in this sense. as pels (2011) concludes on the basis of a review of dutch literature, a crystallized view on dealing with diversity on a religious, cultural or ethnic basis, or with tensions on these issues is still farfetched. research of the city of amsterdam (gemeente amsterdam 2005) among 25 schools for secondary education points to an increase in incidents between groups of pupils as well as between minority pupils and teachers. teachers interviewed by leeman (2003) report problems with teaching on politically laden subjects as the middle east, terrorist attacks or religion. not only the content of education is of importance, but also teaching competence and style. leeman (2003) found that teachers are at a loss finding ways to handle difficult discussions in which respect and consensus are difficult to reach. in order to ensure that lessons can continue orderly and to maintain a relatively peaceful atmosphere in the class, teachers tend to avoid topics that touch on religious and ethnic - cultural diversity. apart from the fact that teachers may lack competencies to effectively cope with tensions in the classroom, they may apply a more or less authoritarian style of approaching their pupils. as we argued, their educational style can also have a positive or negative influence on radicalization, just as we discussed for parents. interestingly, schools that provide vocational education where minority pupils are overrepresented tend to prefer authoritarian education instead of interactive or participative education (mooren 2006 ; onstenk 2006). again, this does not seem to be an effective style for developing democratic dispositions and acting. research in amsterdam (gemeente amsterdam 2005) shows that generally the commitment or loyalty of minority children to their school is greater if there is more individual attention for students. this last finding is corroborated in other research : young muslims mention the important support they felt from a single teacher who did take notice and interest (pels 2008 ; pels. this is an important fact, because youngsters who are susceptible to radicalization tend to have a strong need for acknowledgement and relationships (buijs. the literature, however, also mentions more or less conscious exclusion of pupils by teachers. exceptions is not uncommon (koole and hanson 2002). the negative influence of discrimination and different treatment of children from minority groups on their well - being at school or college, motivation and achievements is broadly documented (e.g. de graaf. since (perceived) deprivation is one of the major root causes for radicalization, we may conclude that current practices in schooling often do not seem apt to diminish the susceptibility to radicalization in youngsters. citizenship education might be one of the answers. in response to threats to democracy by a violent political islam and extremism from the right, and the resulting social instability and feelings of insecurity, many western countries have welcomed citizenship to their political and educational agenda (brubaker 2001). however, in many dutch schools citizenship education is taking a one - sided turn, accentuating individual rights and (moral) obligations and focusing on students of non - western descent to assimilate. it does not stimulate teachers and students to take a reflective stance on inequalities and cultural pluralism in society (leeman and pels 2006). finally, it may not only be the education within families or schools in itself that has an influence on the onset of radicalization, it is also possible that a lack of a good functioning (inter ethnic) civil society is an obstacle. we may presume that interaction and preferably co - operation between families and schools will have a diminishing effect on radicalization. particularly for youngsters who are vulnerable due to perceived discrimination and injustice in society and who are searching for an authority figure, the cooperation between these socializing institutions might be crucial. recently, there is a growing interest in collective socialization, which is an active engagement between and cooperation of informal and formal educators in the community. examples are a communal formulation of rules (intergenerational closure), exchange of information and advice and informal social control and support. these forms of social capital are not self - evident, on the contrary, one of the undermining factors is the presence of an ethnic heterogeneous population and concomitant language, social and cultural hurdles (sampson. available dutch research shows that the two educational domains we have highlighted are often separate islands that are unable to realize sufficient bridging. in practice cooperation between parents and schools often plods along heavily (pels 2011). on the contrary, both parties may even hinder or undermine each other s intentions. for example, research in amsterdam schools showed that parents and schools differed in the messages they provided about the murder of theo van gogh (visser and slot 2005) and another study among amsterdam schools showed that a wider gap between migrant parents and the school increases the distance between migrant and native youngsters (interculturele verhoudingen 2005). this could lead to an educational vacuum of which the signs are visible in the public domain in which groups of youngsters take a lead in their own socialization (pels 2003). research on radicalization tends to focus on adolescents, because it is likely that radicalization finds its roots in this developmental stage.. an interesting use of general psychological insights into the reduction of extremist views can be found in lilienfeld. they translate the results of the psychological research on biases in general into proposals for debiasing adults and children who have radicalized views. education about specific cognitive biases, perspective taking, active open - mindedness and delayed decision making are among the methods that might be of use. we stated that it is plausible to assume a relation between the ideals of education on the one hand and the onset or prevention of radicalization on the other hand. the intergenerational transmission of ideology, so we argued, may be profound in the context of migration, inducing more intensified communication about ethnic - cultural or religious differences. there is empirical research that showed a relation between extreme right - wing convictions of parents and those of their children. it is important that this research be expanded and also includes muslim families, for ideological transmission has not been researched within these families. in addition, we claimed to have good reasons for believing that the style of education has a positive or negative influence on the onset of radicalization. more particularly, we presupposed that an authoritative style of education is conducive to the development of a democratic attitude provided it is complemented with the appropriate democratic content. the empirical literature we reviewed does not give us sufficient evidence to be able to conclude that this presumption is correct. we also formulated the presumption that democratic ideals and moral education can prevent radicalization, by adequately responding to signs of moral distancing and stimulating adherence to moral rules and respect for the liberal moral rights of others. however, we did find that minority and native parents as well as and teachers struggle with their educational tasks in the multi - ethnic context, especially with respect to the tensions, conflicts and discrimination that may arise in this context. we believe it is of eminent importance that the knowledge gap in this field be closed. firstly, particular attention should be given to the way in which parents pass on ideas and evaluations about society, which difficulties parents experience when their youngsters come under the influence of radical peers or organizations, which influence this has on family life and how parents can be assisted. secondly, it is important to investigate the aims and content (and ideals) of education that parents and teachers provide as well as the influence of these aims and content on the development of a democratic disposition or radicalization of youngsters. if we have a better understanding of these two issues, policy can be developed to assist parents and teachers in educating youngsters, with a particular view to prevent radicalization. thus, this knowledge is not only important for scientists, but may be helpful for developing interventions that support parents and teachers (weine. schools and families are underappreciated sources of informal social control and social capital that may constrain islamic radicalism and right - wing extremism. we believe that it is important that not only specific programs are developed, but that general programs for parental support and family interventions also enclose scientific knowledge about the specific difficulties parents can face in a multi - ethnic context. moreover, in current teacher education and social work training - programs, little attention is given to the fact that a significant number of families come from other regions of the world, or face the challenge to raise their children in a multi - ethnic context (e.g. pels 2010). parents and pupils can be more successfully supported if social workers and teachers are sensitive to their needs, committed to giving them a voice and competent to deal with controversial issues (davies 2009 ; howard and hodes 2000 ; pels 2011). we do agree with de winter (2006), who suggests that it is unlikely that changing education of youngsters who are radicalizing is efficient if governments do not take sufficient effort to change society into a truly democratic and just one. youngsters should experience that it is indeed in their favour to act and think democratically. thus, the state should not only stimulate democratic education, but also be a model to the youngsters and aim to ensure that all citizens are able to make use of their democratic rights and fulfil their democratic duties. this article is distributed under the terms of the creative commons attribution noncommercial license which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. | background and objectiveresearch into radicalization does not pay much attention to education. this is remarkable and possibly misses an important influence on the process of radicalization. therefore this article sets out to explore the relation between education on the one hand and the onset or prevention of radicalization on the other hand.methodthis article is a theoretical literature review. it has analyzed empirical studies mainly from european countries about the educational aims, content and style of muslim parents and parents with (extreme) right - wing sympathies.resultsresearch examining similarity in right - wing sympathies between parents and children yields mixed results, but studies among adolescents point to a significant concordance. research also showed that authoritarian parenting may play a significant role. similar research among muslim families was not found. while raising children with distrust and an authoritarian style are prevalent, the impact on adolescents has not been investigated. the empirical literature we reviewed does not give sufficient evidence to conclude that democratic ideal in and an authoritative style of education are conducive to the development of a democratic attitude.conclusionthere is a knowledge gap with regard to the influence of education on the onset or the prevention of radicalization. schools and families are underappreciated sources of informal social control and social capital and therefore the gap should be closed. if there is a better understanding of the effect of education, policy as well as interventions can be developed to assist parents and teachers in preventing radicalization. |
anatomical and physiological changes during pregnancy have the potential to affect the musculoskeletal, cardiovascular, and respiratory system. participation in a wide range of recreational activities appears to be safe during pregnancy in the absence of either medical or obstetric complications, and 30 minutes or more of moderate exercise a day on most, if not all, days of the week are recommended for pregnant women. women who exercise while pregnant have fewer complaints during pregnancy and have improved cardiovascular fitness and improved sense of self ; and more than 90% of women who exercise during pregnancy continue to exercise after delivery. not only is exercise beneficial during pregnancy but even at the postpartum period which is the few weeks after delivery up to about 24 weeks. generally, studies have established the importance of regular exercise during the postpartum period [2, 5 ]. return to physical activity after pregnancy has been associated with decreased incidence of postpartum depression, anxiety and sleep disorders, prevention and treatment of urinary incontinence [4, 6 ], less likelihood to retain weight gained during pregnancy, and prevention of diastasis recti abdominus. postpartum exercise also improves aerobic fitness, high - density lipoprotein - cholesterol levels, insulin sensitivity, and psychological well - being. physical activity during postpartum is both a recommended and an essential contributor to maternal health. pregnant women face unique challenges to exercise during pregnancy and during the postpartum period. however, studies have demonstrated that postpartum women are at high risk for physical inactivity and generally show lower levels of leisure - time physical activity compared to their prepregnancy state. understanding the beliefs, barriers, and enablers regarding physical activity during the postpartum period can help to more effectively tailor physical activity interventions. self - efficacy has particularly been shown to be important for overcoming pregnancy - related barriers, and it plays an important role as a mediator of exercise [10, 11 ]. based on the principles of self - efficacy theory, intervention would be associated with improvements in perceptions of one 's physical abilities to complete exercise (i.e., task self - efficacy), self - management competencies related to completing exercise (i.e., self - regulatory efficacy), satisfaction with one 's body, overall negative mood, and actual physiological changes. although postpartum women have been shown to benefit maximally from physical exercise, before now, it is not known whether nigerian women engage in postpartum exercise, and data on issues surrounding physical exercise of postpartum women from nigeria was not available. this study was carried to (1) explore the physical exercise profile of a cross - section of postpartum women from nigeria, (2) to characterize their exercise self - efficacy, and to (3) describe the link between sociodemographic factors and their exercise self - efficacy. the participants in this study were consenting postpartum women who were attending postnatal clinics of the university college hospital, ibadan and adeoyo maternity teaching hospital, yemetu, ibadan. these two hospitals are the largest antenatal and postnatal clinics in ibadan, south - western nigeria. participants who qualified for eligibility into the study were those who were not physically challenged and those who did not give history of being excluded from exercise participation on account of medical considerations. using a purposive sampling technique, the eventual sample included in this cross - sectional study represents the total number of those who consented and who met the eligibility criteria within a 12-week data collection period. a self - developed questionnaire was used to record the sociodemographic and exercise profile of the participants. questions enquired about participants ' age, marital status, religious affiliations, level of western educational attainment, employment status, and total monthly income. the participants were also asked whether they knew that they could engage in physical exercise within the postpartum period if there were no medical caveats. questions also sought to know if any of them were already on any physical exercise, the type of exercise and whether they were registered or belonged to any exercise support group such as family exercise group, gymnasia group, swimming groups, or bicycling groups. the exercise self - efficacy scale was used to retrieve data on the self - efficacy of the participants to undertake physical exercise. the scale measures the confidence in one 's ability to persist with exercise in various situations representing the areas of negative affect, resisting relapse, and making time for exercise. the scale is on a four - point likert scale used to rate each item from 1 = not at all true to 4 = always true. a high score indicate a high level of self - efficacy, while a low score indicates a low level of self - efficacy. the exercise self - efficacy scale had demonstrated reliability (cronbach 's alpha 0.917) and validity (correlated with minutes of exercise per week (r = 0.41 ; p = 0.0001) and health status (r = 0.37 ; p = 0.0001)). the questionnaire that assessed sociodemographic and exercise profile of the women and the exercise self - efficacy scale were all translated from english to yoruba language and the exercise self - efficacy scale was taken through adaptability to the environment. the choice of yoruba language was based on the fact that the study was conducted in the part of nigeria that is predominantly occupied by yoruba speaking people. the panel sat to identify and resolve any inadequate, vague, or ambiguous expressions and concepts. all identified discrepancies between the forward and backward translations and the existing versions of the questionnaires were also resolved and properly synthesised leading to the production of a complete translated version of the questionnaires. the final stage of the adaptation process was the pretest and was conducted on 20 postpartum women. each participant completed the questionnaire and was interviewed to probe about what he or she thought was meant by each item on the questionnaires. all areas of difficulty encountered during the filling of the questionnaires were also identified and corrected. ethical approval for the study was sought and obtained from the university of ibadan / university college hospital (ui / uch) health research ethics committee (ui / ec/12/0114). approval was also sought from the authorities of the two postnatal clinics in the hospitals where the study was carried out. a letter stating the purpose of the study, assuring the respondents of confidentiality, and seeking for their informed consent was distributed along with the questionnaires. the questionnaires were hand - distributed and collected by the researchers after completion. however, where immediate collection of the questionnaires was not possible, the collection was done on the next available clinic appointment. descriptive statistics of frequencies and percentages were used to describe the data that were presented as categorical, while some other data were expressed as bar charts. the exercise self - efficacy scale is presented in a continuum ranging from 10 as the lowest exercise self - efficacy and 40 as the highest. there were no cut - off points to describe that a participant has a low, moderate, or high exercise self - efficacies. based on this, percentile grading was applied to the exercise self - efficacy data which was later converted to categories of low, moderate, or high exercise self efficacies. the exercise self - efficacy data were categorised into low, moderate, and high based on scores at the 25th, 50th, and 75th percentiles, respectively. in order to find association between exercise self - efficacy and each of participation in physical exercise and sociodemographic characteristics, the exercise self - efficacy scores were further categorised into those who had low to moderate exercise self - efficacy and those who had high exercise self - efficacy. fisher 's exact test was thereafter used to find association between exercise self - efficacy and each participation in physical exercise and sociodemographic characteristics. statistical analyses were conducted using the international business machines (ibm) statistical package for the social sciences (spss) version 20 (ibm corporation, new york, ny, usa). the age ranges of most of the participants in this study were 2130 years (45.6%) and 3140 years (46.9%) with mean age of 31 6.3 years (table 1). more than half of them (52.2%) were self - employed, 140 (61.4%) reported a maximum of 48 hours of work per week, and majority of them (80.3%) gave a history of having one to three children. table 2 shows that 139 (61.0%) of the women were not aware that they could undertake physical exercise to enhance health in the postpartum period, while close to half (47.8%) were not engaged in any physical exercise programme. however, for those who were engaged in physical exercise, brisk walking appeared to be the most adopted individual form of exercise (16.2%). among those who were engaged in exercise programmes, 22 (18.5%) claimed to exercise only once in a week, while 20 (16.8%) claimed to undertake their mode of exercises daily. a total of 176 (77.2%) of the postpartum women reported that they had no any type of exercise enhancing gadget, but free weights were recorded as the most available and only among 20 (8.8%) of the participants. majority of the women (89%) claimed they did not belong to any exercise support group (figure 1(a)). the remaining one - tenth of the women was distributed into swimming, gymnasia, and family - facilitated exercise groups. the scores of exercise self - efficacy presented by the postpartum women are presented in figure 1(b). the 25th percentile was marked by a score of 26 out of 40, while the 50th and 75th percentiles were marked by scores of 29 and 32, respectively. for the ease of interpretation, those who scored between 10 and 25 were classified as having low exercise self - efficacy, 26 to 28 as moderate, and 29 and over as high exercise self - efficacy. one hundred and thirteen (49.6%) of the participants presented with moderate exercise self - efficacy. table 3 presents the association between exercise self - efficacy and each of physical exercise participation and sociodemographic characteristics of the women. out of the variables considered, it is observed that exercise self - efficacy was significantly associated with being in an exercise programme (p = 0.00001), age (p = 0.00001), employment status (p = 0.004), number of work hours per week (p = 0.00001), total monthly income (p = 0.00001), and number of pregnancies (p = 0.00002). the table shows that most of the women who were already in an exercise programme 101 (84.9%) reported high exercise self - efficacy compared to those who had moderate exercise self - efficacy where most of them (88.1%) reported no current exercise programme. the table also shows that significantly higher proportions of the women who were 30 years or younger (78%) had higher exercise self efficacies compared to those who were older than 30 years (20%). high exercise self - efficacy was also seen to be significantly more in those who were not employed (73.3%) compared to those who were in paid employment (46.5%). although number of children did not significantly relate with higher exercise self - efficacy, a slightly higher proportion (50.3%) of those with lesser number of children were seen to have higher exercise self - efficacy compared to those with more than three children. this study was carried out to explore the physical exercise profile of a cross - section of postpartum women from nigeria, to characterize their exercise self - efficacy and to describe the link between exercise self - efficacy, and each of participation in physical exercise and sociodemographic characteristics. the main findings from this study include the following : (1) more than half of the postpartum women were not aware that they could engage in health enhancing physical exercise in the postpartum period ; (2) close to half of them were not involved in any exercise programme, and majority of them did not belong to any exercise support group ; (3) for those who were engaged in physical exercise, brisk walking was reported as the most adopted form of activity, and more than one - third of the women did the exercise for less than three days in a week ; (4) about half of the women had moderate exercise self - efficacy ; (5) being in an exercise programme was associated with exercise self - efficacy, and exercise self - efficacy was found to be linked with age, employment status, number of working hours per week, monthly income, and number of pregnancies. that most of the women in this study who were between the ages of 21 and 40 years may indicate the fact that this is the age - bearing range of the women in this study. this finding can not be interpreted beyond this point because this might as well be by chance since the participants in this study were a sample of postpartum women from only two hospitals in ibadan. this might not be representative of the entire postpartum women in ibadan who may have registered for their pre- and postnatal care in many other government and private hospitals within and around the city. in a previous study that considered 349 pregnant women in nigeria, about two - third of the women were between 25 and 35 years, while in another study of 518 pregnant women, more that 80% were in the 2039 years bracket. information was sought on the number of pregnancies and children that the women have had. it was observed that majority of them have had one to three pregnancies and one to three children. a previous study on household size and composition conducted in the south - western city of abeokuta which happens to be from the same geographical location with ibadan where this present study was carried out also reported the highest number of children to be four (29.8%) followed by three (23.5%). for the overall health of women in the postpartum period, physical exercise has been well documented to be necessary and beneficial [2, 4, 5 ]. scott also reported that most women actually want to exercise after childbirth to lose the weight they gained during pregnancy. notwithstanding the numerous documentations on these benefits, more than half of the women in this present study reported that they were not aware that they could engage in health enhancing physical exercise within the postpartum period. as a followup, it was discovered in this study that about half of the women were actually not engaged in any form of physical exercise during the postpartum period. this observation is against the report that women with no complications during pregnancy or delivery can resume exercise immediately after the delivery [3, 4 ]. it has also been reported that rapid resumption of exercise has no adverse effects, although gradual return to former activities is advised. the lack of awareness exhibited by the women could, however, be an apparent contributor to the poor subscription to postpartum exercise seen among the women in this study. although many exercise options were being adopted by the women who were into exercise during the postpartum period, it was observed that brisk walking was the most subscribed individual type of exercise, while fairly more women reported combining two or more exercise modalities. the reason for adoption of brisk walking as the most applied individual exercise is not fully known, but it is taught that its simplicity and the fear of perceived risks associated with more demanding exercises may be the strong factors in favour of its adoption. it has been reported that some women are afraid to participate in physical activity, especially vigorous exercises, thinking it will negatively impact breast milk production and breastfeeding. whether the women did the brisk walking at health - enhancing intensity or not is not known because the speed at which they walked could not be ascertained. brisk walking that is carried out at an energy requirement of 35 metabolic equivalents (mets) is equivalent to brisk walking at 3 - 4 mph, and this yields a moderate intensity activity level. while the exercise types of the few women who engaged in exercise cut across activities like walking, swimming, cycling, jogging, and weight lifts, more than one - third of them were only doing it for less than three days in a week. this may not be sufficient for health gains as the centers for disease control and prevention and american college of sports medicine recommendation for exercise aimed at improving the health and well - being of nonpregnant individuals, suggest that an accumulation of 30 minutes or more of moderate exercise a day should occur on most, if not all, days of the week [18, 19 ]. the availability of exercise equipment such as bicycle ergometer, treadmill, and free weights among others, which may facilitate physical exercise among the women in this study, was highly limited as about three out of four could not report possessing any equipment. this might have played a role in the poor adoption of exercise among the women. for instance, some postpartum women had indicated that having home exercise equipment facilitated or would facilitate their physical activity. apart from the lack of personal exercise equipment, almost all the women were also not attached or registered with any exercise group or have a link with any family exercise group. only a little fraction could claim registration with an exercise group or family exercise buddy. according to scott, women who are most successful at incorporating a regular routine of physical activity into their life after delivery have higher self - esteem and feel more supported by family and friends. the author further claimed that if women have support for exercise from family and friends, both in the form of verbal encouragement and companionship during exercise, they will more likely initiate and maintain a regular exercise program. this assertion has also been withheld recently by nicklas. who reported that finding an exercise buddy or a group (including group exercise classes) facilitated exercise participation among postpartum women. gyms and community groups could facilitate physical activity for mothers of newborns by scheduling classes or group activities for the women together [4, 20 ]. exercise self - efficacy has been shown to be an important regulator of exercise behaviour [8, 1012 ]. it was interesting to note that close to half of the women in this study presented with moderate exercise self - efficacy, while another slightly lower proportion presented with high efficacy level. however, most of the women who reported that they were already engaged in exercise programmes were the ones with high, not moderate exercise self - efficacy. this implies that moderate amount of exercise self - efficacy, though numerically good, may not practically suffice to get the group of women in this study to exercise as more of those with high exercise self - efficacy were the ones observed to engage in exercise programmes. the reason for a prerequisite of high exercise self - efficacy is not known, but it is observed that being in exercise programme was significantly linked with higher exercise self - efficacy, and exercise self - efficacy was itself significantly linked with age, employment status, number of working hours per week, monthly income, and number of pregnancies. some of these sociodemographic characteristics may have served as either facilitators or barriers to attainment of postpartum physical exercise. for instance, women with newborn babies list many barriers to physical exercise with the most common being lack of assistance with childcare and insufficient time [21, 22 ]. another report on postpartum women with gestational diabetes documents barriers to physical activity to include lack of motivation / fatigue, lack of time, and financial constraints. the potential clinical benefit of this study is that it has been able to shed more light on a number of issues surrounding the participation of a group of nigerian women in postpartum physical exercise. with the findings from this study, it has become known that a group of postpartum women from nigeria are not into postpartum exercises, and this will serve as documented evidence to the fact that the women are yet to maximally benefit from the various clinical health benefits associated with postpartum exercise. the array of details that have relevance with the promotion of physical exercise among these women that have been revealed in this study can also be looked into in the planning of realistic exercise programmes for women in this group. a striking observation in this study is the fact that being involved in postpartum exercise requires high rather than moderate exercise self - efficacy meaning that this psychological construct needs to be amplified in order to get this group of women to exercise. when individuals are able to improve perceptions of both their physical abilities (i.e., task self - efficacy) and ability to overcome barriers to exercise (i.e., self - regulatory efficacy), they tend to maintain their assigned exercise regimens better. the first one bothers on the relatively small sample size considering the fact that the women in this study were recruited from only the two largest hospitals in ibadan. hence, this sample may not necessarily represent the physical exercise profile of postpartum women from other hospital settings. in addition, it could not be ascertained whether the lack of exercise in a majority of the women were influenced by a number of other factors that were not considered in this study. it is, however, observed that the exercise self - efficacy which plays a major role in exercise participation is mediated by a number of sociodemographic characteristics that have been listed in this study. these characteristics may be looked into in an attempt to improve exercise self - efficacy of postpartum women. it is concluded that most of the nigerian postpartum women who participated in this study were not aware that they could engage in physical exercise during their postpartum period and hence most of them were not participating in the exercise. most of the women had moderate to high level of exercise self - efficacy, but participation in postpartum physical exercise was linked to a high exercise self - efficacy. high exercise self - efficacy was also linked with lower age, not in employment, lower hours of work per week, higher income, and higher number of pregnancies. strategies to improve exercise self - efficacy and increase awareness and adoption of postpartum exercise among this group of women are highly desirable. for further studies, | physical exercise during postpartum period is beneficial to mothers, and the health gains are abundantly reported. this study characterises the postpartum exercise profile of a group of nigerian women and reports how their exercise self - efficacies are influenced by sociodemographic characteristics. participants were women attending the two largest postnatal clinics in ibadan, south - western nigeria. a self - developed questionnaire assessed the socio - demographic and exercise profile of participants, while the exercise self - efficacy scale assessed their exercise self - efficacy. about two - third (61.0%) of the participants were not aware that they could undertake physical exercise to enhance postpartum health, and 109 (47.8%) were not engaged in any exercise. those who exercised did so for less than three days / week, and 89% of the women did not belong to any exercise support group. exercise self - efficacy was significantly (p < 0.05) associated with being in an exercise programme, age, employment, work hours / week, monthly income, and number of pregnancies. most of the women were not aware they could engage in postpartum exercise, and about half were not undertaking it. more women with high compared to moderate exercise self - efficacy undertook the exercise. efforts at increasing awareness, improving exercise self - efficacy and adoption of postpartum exercise are desirable among the nigerian women. |
reliable surgical therapy for gist is the complete tumor resection. in principle, the resection of involved organ has been recommended for preserving physiological functions, and lymph - node dissection is unnecessary. this study described a patient who underwent the thoracoscopic enucleation of an esophageal gist and survived without the recurrence of tumor for 6 years after surgery. a 62-year - old male was found to have a well - demarcated mass with a smooth surface at the right side of the lower esophagus by chest computed tomography (ct) upon medical check - up (fig. 1). positron emission tomography (pet) revealed the accumulation of f - fluoro-2-deoxyglucose (fdg) at the tumor. the maximum standardized uptake value was 4.0, increasing to 4.8 in the late phase. endoscopic ultrasonography showed a mass 2 cm in diameter arising in the third layer 40 cm from the incisor teeth (fig. these findings diagnosed the lesion as an esophageal submucosal tumor with suspecting an esophageal leiomyoma or gist. being under general endotracheal double - lumen anesthesia with split - lung ventilation, the patient was allowed to lie on the healthy side (left) and posture lateral decubitus. a 6-cm long access incision was made at the posterior axillary line in the 10th intercostal space. two 10.5-mm ports were made at the seventh intercostal space in the anterior axillary line and other at the same intercostal space in the posterior axillary line. after no adhesion in the thoracic cavity was observed, the pulmonary ligament was dissected and the lower lobe of the right lung was moved anteriorly. an incision was made in the mediastinal pleura, and the mass was confirmed at the outer longitudinal muscle of the lower esophagus. the operation time was 118 min, and the blood loss was 11 g (fig. macroscopic examination found that the removed white parenchymal mass was 29 20 14 mm in size. histopathological examination showed that the specimens stained with hematoxylin and eosin - contained tumor cells, which had elongated oval nuclei and eosinophilic and spindle - like reticulum, were arranged in fascicles without mitosis. immunohistochemical results were positive for c - kit, s-100 protein, cd34 and vimentin, and the specimen was diagnosed as a low - risk gist (fig. the patient took an uneventful postoperative course, was allowed to remove the surgical drain after confirming the clinical status by esophagography on postoperative day 9, and discharged on postoperative day 13. at 6 years after surgery, the patient was found to be healthy without tumor recurrence. the white arrow head indicates a clearly distinguishable mass having a smooth surface at the right side of the lower esophagus. (a) tumor with a normally appearing mucosa was located 40 cm from the incisor teeth. (b) hypoechoic submucosal tumor (asterisk) with annular localization, arising from the submucosal layer. the black dash line and asterisk indicate the gist ; d, the diaphragm ; vd, the vertebral body. (b) immunohistochemical - stained specimen showed that the cells were positive for c - kit. the white arrow head indicates a clearly distinguishable mass having a smooth surface at the right side of the lower esophagus. (a) tumor with a normally appearing mucosa was located 40 cm from the incisor teeth. (b) hypoechoic submucosal tumor (asterisk) with annular localization, arising from the submucosal layer. the black dash line and asterisk indicate the gist ; d, the diaphragm ; vd, the vertebral body. (b) immunohistochemical - stained specimen showed that the cells were positive for c - kit. in recent years, guidelines for managing gists are prepared by the national comprehensive cancer network (nccn) and issued in 2004. gists are known to consist of spindle and epithelioid cells. among gastrointestinal mesenchymal tumors, gists are stained positively for c - kit or cd34, and the diagnostic rates of the tumors are < 1% of all gastrointestinal tumors. esophageal gists are extremely rare, accounting for only 1% of all gists [2, 3 ]. although the results of fdg - pet have been reported to correlate with the degree of malignancy of gist, the definitive diagnosis is difficult to be performed. on the other hand, fdg - pet is effective for evaluating postoperative recurrence and the response of gist to chemotherapy. for treating gist, if the tumor is resectable, the partial resection of affected organ is the treatment of choice with considering the preservation of organ functions. in patients with unresectable tumors, recurrence or metastasis, chemotherapy with imatinib mesylate (gleevec) is recommended [1, 2 ]. esophagectomy including partial resection, as a conventional treatment for esophageal gist, is more invasive than the resection of other parts of the gastrointestinal tract and remarkably reduces the quality of life of patients after surgery. recently, thoracoscopic enucleation has been used for treating small and low - risk gists confirmed histologically. previous case reports on esophageal gists have described only small numbers of patients, and long - term outcomes after enucleation have rarely been reported. however, gists are difficult to be diagnosed preoperatively, and esophageal submucosal tumors such as leiomyoma are often initially diagnosed, followed by the diagnosis of gist on postoperative pathological examination. the patient in this report was being followed up 6 years after surgery, and there was no evidence of recurrence. in patients with small tumors minimally invasive thoracoscopic surgery could particularly be useful for the diagnosis and treatment of gist appearing in the esophagus. this report described a patient who survived for a long term without tumor recurrence after the thoracoscopic enucleation of an esophageal gist, considered a rare tumor. being a lower aggressive procedure, the thoracoscopic enucleation could allow patients to survive for a long term and their quality of life to be enhanced. | the goal of surgical treatment for gastrointestinal stromal tumor (gist) is the complete resection of the tumor. a 62-year - old male had a clearly distinguishable mass having a smooth surface at the right side of the lower esophagus by computed tomography. thoracoscopic resection of the tumor was performed. immunohistochemical analysis showed that the tumor was positive for c - kit and cd34 without mitosis, and diagnosed to be a low - risk gist. at 6 years after surgery, the patient survived without recurrence. this study described the long - term surviving patient without the recurrence of tumor after the thoracoscopic resection of an esophageal gist. |
cancers of the digestive tract are among the foremost causes of mortality, not only in slovakia, but also worldwide. familial adenomatous polyposis (fap) is an autosomal dominant disease characterized by development of hundreds or thousands of polyps in the gut, with an almost 100% probability of degeneration into malignant process in the second decade of life. this disease is induced by germ - line mutations in the tumor - suppressor apc (adenomatous polyposis coli) gene, which normally inhibits cell growth. an inactivating mutation of this gene is also present in up to 7580% of sporadic colorectal adenomas and carcinomas. the spectrum of these somatic mutations is very similar to that of the germ - line mutations. the most common disease - causing mutations (95% of all known) create stop codons or frame shifts, which result in the lost of apc protein function, which is a critical event in the process of carcinogenesis. the majority of the approximately 700 detected pathogenic apc mutations occur in exon 15 and over 60% of these are in the region between codons 12861513, also known as the mutation cluster region (mcr), which accounts for less than 10% of the coding region. the high concentration of apc gene mutations in region 230 bp raises the question of their genesis. this phenomenon is frequently explained by the weakening of the region due to its specific primary dna structure. there are 2 critical spots in the mcr region (2 specific hypopolymers sites) : 1) sequences aaaagaaaga (codons 13071311), where deletion of aaaag or aaaga is very frequent ; and 2) the second hotspot mutation is a 1-bp deletion that occurs within the repeat sequence cctaaaaataa (bp 43784382). these 2 mutations are very probably induced by a polymerase slippage error within repeated nucleotide sites. each mutation in the mcr leads to the synthesis of a truncated apc product, which is able to provide some residual function to bind -catenin despite the lack of any -catenin degrading activity. but for keeping this function it must contain at least the first 20 amino acid repeat domain, so the 5 border of the mcr is located right after this area imposed by the necessity of controlling the activity of -catenin in a cell cycle - dependent manner. factors that lead to mutations and tumorigenesis of colorectal cancer are not strictly defined yet, so the need to analyze them is still very real. the idea that bacteria may play an important role in the formation and development of colorectal cancer is currently widely accepted [1114 ]. moore reported that 15 bacterial species were significantly associated with a high risk of colon cancer and other authors have recently published reports on which microorganisms cause cancer in humans [1618 ]. based on detection of apc - like sequences in intestinal bacteria isolated from fap patients, we present a new hypothesis / approach regarding the induction of the apc gene mutation and/or colorectal tumorigenesis. genomic dna was extracted from peripheral blood lymphocytes of fap patients using the qiaamp dna blood kit (qiagen). bacteria isolated from rectal swabs were amplified overnight in lb medium and bacterial clones were prepared after dilution on lb agar plates. bacterial chromosomal dna was extracted by use of the qiaamp dna kit (qiagen). the sequences of the primers used for the apc gene were described by groden.. pcrs were performed from approximately 150200 ng of genomic dna, 80 mm dntp, 1 mm 10pcr buffer (qiagen), 0.5 u of taq polymerase (qiagen), 10 pmol of each primer, to a total volume of pcr mixture of 25 l. dna samples were amplified using the cycling program : 5 min at 94c, once ; 1 min at 94c ; 1 min at annealing temperature from 58 to 63c ; 1 min at 72c, 30 times ; and 7 min at 72c, once. amplicons were purified by solid - phase extraction and bidirectionally sequenced with the pe applied biosystems big dye terminator sequencing kit according to the manufacturer s instructions. sequencing extensive products were analyzed on a pe applied biosystems abi - prism 310 sequencer. bacterial protein extracts of tested fap patients were prepared from 15 ml overnight cultures, that were transferred into 25 ml lb medium with kanamycin and let cultures grow to optimal optical density. cultures were divided into two parts one with iptg to final concentration of 1 mm iptg / ml and one without iptg. both cultures were grown overnight at 37c and protein extracts were prepared by centrifugation at 3000 rpm for 15 min. pellets were sonicated and 10 l of 100 mm pmsf was added and centrifuged at 13000 rpm for 15 min. bacterial protein extracts for positive control were prepared similarly from 3 ml of overnight cultures of clone de3plys bearing plasmid with cloned complete apc gene (paper prepared for publication). proteins after electrophoresis were transferred from acrylamide gel to nitrocellulose (nc hybon membrane) overnight at 50 ma. membrane was incubated in tbs - t buffer and blocked using 5% milk for 1 hour at room temperature. the blocking buffer was removed and the membrane was washed with tbs - t buffer. appropriately diluted mouse monoclonal apc antibody (ali 1228, abcam) and rabbit polyclonal antibody to apc (ab15270) in tbs - t buffer with 5% milk was added to the membrane and incubated overnight at 4c on a shaker with a rocking motion. the membrane was washed with tbs - t buffer and incubated for 1 hour at room temperature in appropriately diluted goat anti - mouse antibody (sc-2005), or goat anti - rabbit igg - hrp : sc-2030 (santa cruz biotech.) in buffer containing 5% milk respectively. consequently, the membrane was washed with tbs - t buffer and ecl solutions were used for visualization. genomic dna was extracted from peripheral blood lymphocytes of fap patients using the qiaamp dna blood kit (qiagen). bacteria isolated from rectal swabs were amplified overnight in lb medium and bacterial clones were prepared after dilution on lb agar plates. bacterial chromosomal dna was extracted by use of the qiaamp dna kit (qiagen). the sequences of the primers used for the apc gene were described by groden.. pcrs were performed from approximately 150200 ng of genomic dna, 80 mm dntp, 1 mm 10pcr buffer (qiagen), 0.5 u of taq polymerase (qiagen), 10 pmol of each primer, to a total volume of pcr mixture of 25 l. dna samples were amplified using the cycling program : 5 min at 94c, once ; 1 min at 94c ; 1 min at annealing temperature from 58 to 63c ; 1 min at 72c, 30 times ; and 7 min at 72c, once. amplicons were purified by solid - phase extraction and bidirectionally sequenced with the pe applied biosystems big dye terminator sequencing kit according to the manufacturer s instructions. sequencing extensive products were analyzed on a pe applied biosystems abi - prism 310 sequencer. bacterial protein extracts of tested fap patients were prepared from 15 ml overnight cultures, that were transferred into 25 ml lb medium with kanamycin and let cultures grow to optimal optical density. cultures were divided into two parts one with iptg to final concentration of 1 mm iptg / ml and one without iptg. both cultures were grown overnight at 37c and protein extracts were prepared by centrifugation at 3000 rpm for 15 min. pellets were sonicated and 10 l of 100 mm pmsf was added and centrifuged at 13000 rpm for 15 min. bacterial protein extracts for positive control were prepared similarly from 3 ml of overnight cultures of clone de3plys bearing plasmid with cloned complete apc gene (paper prepared for publication). proteins after electrophoresis were transferred from acrylamide gel to nitrocellulose (nc hybon membrane) overnight at 50 ma. membrane was incubated in tbs - t buffer and blocked using 5% milk for 1 hour at room temperature. the blocking buffer was removed and the membrane was washed with tbs - t buffer. appropriately diluted mouse monoclonal apc antibody (ali 1228, abcam) and rabbit polyclonal antibody to apc (ab15270) in tbs - t buffer with 5% milk was added to the membrane and incubated overnight at 4c on a shaker with a rocking motion. the membrane was washed with tbs - t buffer and incubated for 1 hour at room temperature in appropriately diluted goat anti - mouse antibody (sc-2005), or goat anti - rabbit igg - hrp : sc-2030 (santa cruz biotech.) in buffer containing 5% milk respectively. consequently, the membrane was washed with tbs - t buffer and ecl solutions were used for visualization. we collected blood samples and rectal swabs from 15 patients with a confirmed fap diagnosis and from 4 healthy persons. bacteria isolated from rectal swabs were amplified overnight in lb medium and each subclone was analyzed for the presence of apc - like sequences using pcr. we analyzed sections a, d, e, f, g, h, h n a q from exon 15 of the apc gene. as a positive control we used a human dna sample from a healthy person. laboratory strain hb 101 and bacteria isolated from the gastrointestinal tract of healthy persons (100 - 5, 77 - 1, k17 - 2 - 5, 164 - 1) were used as negative controls in all reactions. pcr products from apc gene defined by primers 15afor-15arev were identified in bacteria isolated from patient 38 - 3 and in bacterial subclone 41 - 1 - 23 from patient 41 - 1 (figure 1, lines numbers 8, 9). similar results were observed by analysis of section defined by primers 15dfor-15drev, but pcr product were also found in samples 60 - 3 and 104 - 1 (figure 2, lines numbers 8, 9). by analysis of the sections 15efor-15erev and 15ffor-15frev, pcr products were identified by all samples except for patient 46 - 2 in both sections and 96 - 3 in section 15efor-15erev (figure 3, lines 12). in section 15gfor-15grev, positive results were by all tested samples (figure 4). results in section 15hfor-15hrev were positive by samples 38 - 1, 38 - 1 - 4, 38 - 1 - 7, 38 - 1 - 9, 38 - 1 - 12, 41 - 1 - 37, 46 - 4, 55 - 1, 55 - 2, 55 - 3, 56 - 1, 56 - 2, 60 - 3, 96 - 3, 155 - 1 and 104 - 1 (figure 5). positive results were recorded for samples 38 - 1, 38 - 1 - 7, 41 - 1 - 37, 46 - 4, 55 - 1, 55 - 2, 55 - 3, 56 - 2, 96 - 3, 155 - 1 and 104 - 1. by analysis of the last two sections results were almost the same and positivity in section 15kfor-15nrev was recorded only for samples 55 - 2 and 104 - 1 and in 15qfor-15qrev only one positive result was observed in sample 55 - 2. pcr products from bacteria, respectively from their subclones, from patient 41 - 1 were sequenced in section f g together with the patient s dna sample and the sequence of human apc gene and subsequently compared using the computer program. the result was more than 95% of the rate of homology in this section (figure 6). in the last part of our project we used seven samples (55 - 1, 55 - 2, 55 - 3, 60 - 3, 96 - 3, 104 - 1, 41 - 1) for determining the possible expression of apc - like sequences, respectively possible production of apc - like protein. protein products were observed in samples 55 - 3, 60 - 3, 96 - 3, 104 - 1, 41 - 1 (figure 7). bacteria isolated from rectal swabs of fap patients and their subclones were analyzed for the presence of apc - like sequences using pcr. the pcr products were found in exon 15, in which were analyzed sections a, d, e, f, g, h, h n and q. in bacteria or their subclones isolated from 15 members of 9 fap families were observed apc - like sequences mostly in sections e, f, g and h. this is very interesting, because this part of the apc gene corresponds with mcr. moreover, sequencing and subsequent software comparison showed about 90% of homology with apc gene. for possible assignment of expression of these sequences, monoclonal and polyclonal antibodies it was proven that both extracellular and intracellular bacterial counts of e. coli were increased in patients with colonic adenoma or carcinoma. in another study, increased adherence and invasion of e. coli was reported in patients with colorectal cancer and crohn s disease. the presence of apc - like sequences in commensal bacteria of the patients may be hypothetically explained as follows : 1) genetic information including apc - like sequences was accepted by bacteria in the intestinal tract from degraded human cells, in particular by macrophages and lymphocytes. acceptance of new genetic information is a basic feature of bacteria, because richer genetic material gives them a better chance to survive. they may represent a very conservative part of the genome ; this original primary structure of the apc gene the first 14 small exons and the large 15 exon might also serve as a matrix for formation of tumor suppressor genes in the highest organisms in the evolutionary process. possibly a function of apc - like sequences, apc - like protein might also be explained in other ways. apc is a multifunctional protein involved in cell adhesion, polarity, migration, mitosis, apoptosis, and neuronal differentiation and plays a key role in so - called -catenin destruction complex, catalyzing the efficient phosphorylation of -catenin, which is subsequently degraded in the proteasome. therefore inactivation of its physiological function in colon cancer cells leads to the stabilization of -catenin, which in turn gives the cell a permanent mitogenic signal. this is the essential mechanism allowing the hyperproliferation of the epithelial cells of the colon [2729 ]. the mutation cluster region (mcr) of the apc gene is located within the central part of the open reading frame, including the so - called 20 amino acid repeats (20r) that are -catenin binding sites. each mutation in this area leads to the synthesis of a truncated apc product expressed in a colorectal tumor. in fap, one mutated allele is germ - line, but the sequence of mutational events affecting both alleles is in this case not a random process [3032 ] and we can observe strong selection for the retention of at least one truncated apc product containing the first 20r (germ - line defect loss of heterozygosity or a truncating mutation occurring before the first 20r, then the next truncating mutation will affect the remaining allele after the first 20r). therefore the 5 border of the mcr is clearly located just after the first 20r ; we have recently shown that it is an important structural motif allowing truncated apc to keep some residual control of -catenin activity for optimal cell proliferation. but there is also an almost systematic selection for truncating mutations occurring before the samp, probably to preclude the formation of a functional destruction complex by eliminating the binding sites for axin / conductin, which involve -catenin degradation. or the selection might depend on altered -catenin binding activity to the third 20r, which contains 2 parts that provide important contact sites to -catenin. therefore almost all apc gene mutations that are selected in colorectal tumors lead to the synthesis of truncated apc products that contain a 20r1 fully competent in -catenin binding. these facts shows, that some -catenin binding activity must be kept and that it is crucial for the tumour cell and the presence of truncated apc seems essential for optimal cell proliferation, but all the consequences in terms of intracellular signalling remain still unknown. on the basis of all these facts we can consider the role of apc - like sequences, respectively apc - like proteins produced by bacteria as an alternative origin of truncated apc products. almost all our samples were positive for the apc - like sequences in the sections e e and f f, which are the particular regions where the 20r1 is encoded. if apc - like protein contains this section, respectively -catenin binding side, then it is probably able to bind to -catenin and this controls its ability to activate transcription, just like truncated apc products. moreover, because of this interaction, the binding domains are occupied by these molecules and are not able to bind with functional apc protein to provide its physiological function. thus, apc - like proteins could probably also operate by the mechanism of competitive inhibition, which might explain the tumor formation in situations in which no mutation of apc gene is detected. extracellular dna has already been found in untreated cultures of a variety of micro - organisms and in the culture medium of mammalian cells [4042 ]. furthermore, extracellular dna that has been spontaneously released by bacterial species amenable to genetic transformation has been shown to be genetically active. anker reported that when human cells and bacteria are both present together, as can be the case during septicemia, peritonitis, or subclinical inflammation of the gut, human cells can take up bacterial dna. both cellular and nuclear membranes can be crossed by nuclear material and this enables it to gain access to the host genome. thus, bacterial dna transcessing into human cells might have medical implications, especially in the process of carcinogenesis. it is possible that the role of bacteria in oncogenesis, such as demonstrated with helicobacter and gastric malt lymphoma or gastric carcinoma, is underestimated. accepted apc - like sequences are not vital for bacteria, so their mutations are without implications for them. but, hypothetically, bacteria with mutated apc sequences might be internalized by human cells, including sperm and oocytes, and mutation could be horizontally transferred by in vivo dna hybridization, and consequently integrated into the human genome where it may create somatic or germ - line mutations. we do not know yet, if confirmation of the presence and function of apc - like sequences in bacteria could be beneficial in analyzing the causes of the disproportionate number of mutations in the apc gene. our results are quite preliminary and they can be considered only as hypothesis - generating because of the limited number of analyzed samples. our study is a pilot project and further research is warranted. if confirmed, this original model could bring new opportunities in research, diagnostics and even therapy of this disease. | summarybackgroundfamilial adenomatous polyposis (fap) is a hereditary disease induced by germ - line mutations in the tumor suppressor apc gene. these initiate the early stages of the adenoma - carcinoma sequence in familial, but also in sporadic (in 80% to 90%), colon tumorigenesis. we found the presence of apc - like sequences in bacteria of fap patients.material/methodswe analyzed bacteria isolated from fap patients rectal swabs. total bacterial dna was isolated and analyzed for detection of apc - like sequences using pcr. we also tested dna homology rate and apc - like protein production.resultswe collected blood samples and rectal swabs from patients with confirmed diagnosis of fap. they were analyzed for presence of sections from exon 15 of the apc gene. most positive results were found in sections located exactly in the area called the mcr (mutation cluster region), where the highest frequency of apc gene mutations were identified. by sequencing pcr products from bacteria in section f g together with a patient s dna sample and human apc gene, we found a more than 90% dna homology rate. we also confirmed production of apc - like protein using western blotting.conclusionsour results suggested two hypotheses. the apc - like protein might have same function as a truncated apc product, which is synthesized in most cases of mutations of apc gene in the mcr region in colorectal cancer cells. alternatively, we can consider the possible existence of horizontal transfer of genetic information between eukaryotic and prokaryotic cells. our study can be considered as a pilot project. for confirmation of our hypotheses, further research is needed. |
balo 's concentric sclerosis (bcs) is a rare and recognized variant of multiple sclerosis (ms). most cases of bcs show acute encephalopathy with a fulminant course that can rapidly become fatal. however, the advent of magnetic resonance imaging (mri) has changed this, and long - term survival has been reported with bcs. imaging features pathognomonic for bcs include alternating rings of demyelinated and myelinated white matter seen on t2-weighted images and concentric ring enhancement on t1-weighted images with gadolinium enhancement. in the earlier stage, many other neurological diseases can mimic bcs because it presents with diverse features and brain mri findings are not prominent in that period. in korea, there has been at least one case report, which described proton magnetic resonance spectroscopy (1h - mrs) findings similar to those in multiple sclerosis. here, we describe the case of a woman who presented with bcs while undergoing therapy for pulmonary tuberculosis. a 24-year - old woman presented with dysarthria and bilateral upper extremity weakness for 3 days. she did not complain of headache, dizziness, nausea, fever, or chills. she had been taking anti - tuberculous medication for pulmonary tuberculosis and tuberculous lymphadenitis over the prior 2 months. on neurological examination, she was alert and well oriented. cranial nerve examination revealed central type facial palsy of the left side and dysarthria ; other cranial nerve functions were normal. the muscle power of the right and left upper extremities were both medical research council (mrc) grade 4. deep tendon reflexes were hyperactive in the bilateral upper extremities, without definite pathological reflexes. sensory function and autonomic nervous system functions, including micturition and defecation, were normal. screening tests for infectious diseases including serum antibodies to human immunodeficiency virus, herpes simplex virus type 1 and 2, varicella zoster virus (vzv), epstein - barr virus, cytomegalovirus, borrelia burgdorferi, and toxoplasma gondii were unremarkable. the adenosine deaminase level in serum was 21 iu / l (normal range : 5.3~17.8 cerebrospinal fluid (csf) examination showed mild protein elevation (88.3 mg / dl) without pleocytosis. there were no oligoclonal bands in the csf, and the igg index was 0.41. visual evoked potentials, brainstem auditory evoked potentials, and somatosensory evoked potentials were normal. initial brain mri revealed multiple mass - like lesions with ring enhancement and peripheral edema. some lesions showed multiple concentric rings with high signal intensity around them on t2-weighted and fluid - attenuated inversion recovery (flair) images. a nested pcr test for mycobacterium tuberculosis in the biopsied tissue was negative. with intravenous dexamethasone treatment (16 mg / day for 18 days), neurological deficits were normalized. the multiple lamellate high signal lesions on t2-weighted and flair images became more prominent in repeat brain mr imaging performed 3 weeks later, though the, peripheral edema and gadolinium enhancement were decreased. this lamellate concentric pattern disappeared in repeat brain mri performed 5 months later (fig. there were not any lesions in the brainstem and the spine mri was not under consideration. the patient did not experience any symptoms or signs of relapse, and neurological deficits were not detected during the follow - up examination 51 months later. traditionally, the diagnosis of bcs is made by postmortem pathological features, and the clinical course of bcs frequently presents as an acute or subacute encephalopathy. therefore, bcs has been considered fulminant and rapidly fatal. with the advent of mri techniques, thus, some cases of bcs have recently been reported to have a good therapeutic outcome. mri findings of bcs show concentric ring patterns on t2-weighted images with enhancement on t1-weighted images, and these findings reflect pathological features of bcs that are characterized by concentric lesions of alternating demyelinated and myelinated bands in the white matter. proton spectroscopy may show a high choline peak and a low n - acetylaspartate peak, similar to acute ms plaques. however, the concentric pattern is not always observed if the mr imaging is not performed early in the course of the disease. patients usually present with symptoms of acute or subacute onset, which progress over a period of weeks to months, suggesting a space - occupying lesion in the brain. although cerebral tuberculoma is a rare condition, it is highly prevalent in developing countries. tuberculosis with cns involvement accounts for 10~15% of all tuberculous infections. in the present case, the clinical presentation of weakness and sensory changes led to the initial suspicion of a cerebral tuberculoma. however, mri showed multiple mass lesions with ring enhancements and a subtle lamellate pattern in some of them. therefore, a stereotactic brain biopsy was needed for the differential diagnosis, and it revealed findings suggestive of a demyelinating disease without evidence of a tuberculous granuloma, sarcoidosis, abscess, or neoplasm. the diagnosis of bcs was finally made based on these typical mr and pathological findings. the follow - up mr images acquired 3 weeks later at the same level showed a more prominent lamellate pattern. it was thought that cytotoxic edema was decreased and thus the outer demyelination became more prominent. in conclusion, it is suggested that bcs should be included in the differential diagnosis of cerebral tuberculoma in developing countries with a high prevalence of tuberculosis, especially when brain mri shows findings atypical for tuberculoma. | balo 's concentric sclerosis (bcs) is considered a rare variant of multiple sclerosis, which often mimics an intracranial neoplasm or abscess. we report the case of a 21-year - old woman presenting with bcs while undergoing treatment for pulmonary tuberculosis. initial brain magnetic resonance imaging (mri) findings were similar to those for cerebral tuberculoma, multiple metastases, or abscesses. however, the pathognomonic concentric sclerosis characteristic of bcs was seen on mri. the antemortem confirmatory diagnosis of bcs was made by follow - up mri and a brain biopsy. it is suggested that bcs should be included in the differential diagnosis of cerebral tuberculoma, especially in developing countries with a high prevalence of tuberculosis. |
a bifocal non - union of shaft of radius associated with ipsilateral non - union shaft of ulna in an adult has not been reported in the literature till date to the best of our knowledge, though few similar cases of fresh fractures have been reported. we report a case of bifocal non - union of shaft radius with non - union ipsilateral shaft of ulna in a 48-year - old right handed male along with discussion of alternative treatment options. we describe an extremely rare and complicated non - union in which our patient got excellent results along with satisfactory functional recovery as a result of appropriate surgical treatment. in clinical practice, non - union in fractures of forearm bones is commonly encountered but non - union of bifocal fracture of shaft of radius is rare. we report a case of bifocal non - union of fracture shaft of radius along with nonunion of ipsilateral shaft of ulna (with implant failure in case of non - union of fracture ulna). we could nt find evidence of any previous reports relating to the surgical treatment of such a non - union in our review of scientific literature. only the cases like one involving management of fresh trifocal fractures of radius along with fracture mid shaft ulna, two cases of management of fresh segmental fractures of radius and shaft of ulna and one case of management of fresh trifocal ulna fracture with bifocal radius fracture with supracondylar humerus fracture in a child have been reported in the past. a 48-year - old right handed male presented to us in the orthopaedics out patient department with chief complaints of deformity in the left forearm and loss of function of left forearm for the last two months. patient had been earlier operated for bifocal fracture shaft of radius and fracture shaft of ulna by open reduction and internal fixation with square nails 4 years back. according to the patient, the square nail for radius was removed one year after primary surgery because of impingement but no record was available with the patient. patient, a bus driver by occupation complained of progressive increase in forearm deformity that got aggravated for the last two months prior to seeking consultation in our institution. on examination, there was gross deformity of left forearm with marked wasting and old healed surgical scar marks on dorsum and ulnar border on inspection (fig. 1 and 2). on palpation, there was painless abnormal mobility at all three fracture sites (two in radius and one in ulna). preoperative clinical picture(anterior view) preoperative clinical picture (posterior view) radiographs revealed bifocal atrophic non - union of radius with non - union of ulnar shaft fracture with broken square nail for ulna in situ (fig. broken square nail was removed followed by freshening of fracture ends and fixation with 7 hole 3.5 mm locking compression plate with bone grafting using blocks of cortico - cancellous graft harvested from the iliac crest. using thompson s approach, radial non - unions were exposed, fracture ends at both the non - union sites were freshened followed by fixation with single 10 hole 3.5 mm locking compression plate after filling the gaps in between fracture ends with blocks of cortico - cancellous bone taken from the iliac crest. wounds were closed on negative suction drains and above elbow back slab was applied (figures 4 and 5). patient was closely observed for the signs of compartment syndrome but the post operative period was uneventful. post operative clinical picture after two weeks, skin staples and back slab was removed and patient was put on physiotherapy in the form of wrist and elbow range of motion exercises. at 6 weeks follow up, fracture started showing signs ofunion and patient was allowed limited activity. at 12 weeks post follow up, the patient who could not hold anything in his left hand at the time of presenting to us, had resumed his occupation as a bus driver and was now holding steering wheel of bus using same left hand and had good functional and cosmetic results (figures 7, 8 and 9), with radiographs showing good consolidation of the fractures (figure 6). x - rays at final follow - up final follow - up clinical image final followup clinical image (continued) final followup clinical image (continued) mazin ibrahim reported a fresh case of unilateral, trifocal diaphyseal fracture of radius with mid shaft ulna fracture managed by fixation of bifocal radius fractures with two titanium dynamic compression plates using henry s volar approach to radius and fixation of ulna with titanium dynamic compression plate as well. in our case, thompson s dorsal approach was used for fixation of non - unions of radius to prevent devascularisation of volar aspect of radius and to use old healed surgical scars on dorsum of forearm from previous surgery. rafiq reported the management of a case of an ipsilateral diaphyseal fracture of radius, ulna and radial head managed with plating of forearm fractures along with radial head replacement. harsh raval reported management of two fresh cases of segmental complex radius fractures with mid shaft ulna successfully treated by combination of nailing, plating and k - wire fixation. ravi mittal and vijay sharma reported the management of case of sspgsfrx ipsilateral fracture supracondylar humerus with trifocal ulna and bifocal radius. mseddi and goa reported good results with intramedullary devices but in our case, intramedullary fixation had failed and hence plating was preferred. ring, in their study of 38 cases of fracture radius and ulna reported successful treatment with plating and autologous cancellous bone grafting. a similar management was carried out in our case. through this case report, we have highlighted successful management of rare non - union with good functional outcome. the present case report is the first of its kind emphasizing the fact that the rigid fixation and autologous cortico - cancellous bone grafting should bethe preferred modality of treatment even in such complex non - unions yielding successful outcome. intramedullary implants have high rate of failure in forearm fractures and should be preferentially treated with plating in adults. non - unions, and especially segmental non - union as seen in our case poses a greater challenge and needs fixation with locking plates with adequate bone grafting. single plate avoids stress shielding and using same approach as used earlier avoids circumferential periosteal stripping. | introduction : a bifocal non - union of shaft of radius associated with ipsilateral non - union shaft of ulna in an adult has not been reported in the literature till date to the best of our knowledge, though few similar cases of fresh fractures have been reported. the case being reported by us is the first of its kind.case presentation : we report a case of bifocal non - union of shaft radius with non - union ipsilateral shaft of ulna in a 48-year - old right handed male along with discussion of alternative treatment options.conclusion:we describe an extremely rare and complicated non - union in which our patient got excellent results along with satisfactory functional recovery as a result of appropriate surgical treatment. |
measurement of the serum chloride (cl) concentration is essential to assess a patient 's acid - base status, because the cl concentration is used to calculate the anion gap (ag) in patients with metabolic acidosis and the cl deficit in patients with metabolic alkalosis [1, 2 ]. the cl concentration is usually determined by a central laboratory - automated biochemical analyzer (central laboratory analyzer), although point - of - care blood gas and electrolyte analyzers (blood gas analyzer) are now available in many clinical facilities. recent studies have shown that electrolyte values determined by a central laboratory analyzer and a blood gas analyzer may differ [37 ]. in such studies, the sodium (na) concentrations measured by a central laboratory analyzer tend to be higher, while chloride (cl) concentrations tend to be lower compared with those measured by a blood gas analyzer, leading to significant differences in the ag as well as chloride deficit between these methods. if the differences are large, they might hamper the clinician 's assessment of the patient 's acid - base status. although the precise mechanisms for this phenomenon are unclear, the dilutional effect of heparin [4, 8 ] and its direct binding to electrolytes [4, 9 ] are thought to be responsible for the lower na and potassium (k) values determined by a blood gas analyzer. however, there are still few explanations for the lower cl values determined by central laboratory analyzers than those determined by blood gas analyzers. we recently encountered a case with end - stage renal disease (esrd) with marked discrepancies in cl concentrations between the two methods, which improved following several sessions of hemodialysis. this case prompted the hypothesis that cl concentrations measured by the analyzers are influenced by acid - base status. the institutional ethics committee waived the need for informed consent for this anonymous retrospective chart analysis. data were collected from staff at otsu red cross hospital as part of standard patient care. we retrospectively collected data from patients admitted to our icu between april 1, 2010 and june 30, 2010, for whom samples were simultaneously measured by a blood gas analyzer and a central laboratory analyzer. in total, 48 pairs of values were collected from 19 patients, and the mean electrolyte concentrations were compared between the two analyzers. the patients ' samples were then divided into two groups ; those from acidic patients (ph 7.40), and we compared the mean differences in electrolyte concentrations measured with both analyzers for sets of samples. we retrospectively collected data measured with the blood gas analyzer that showed severe acidemia (ph 7.20) in patients admitted to our hospital between april 1, 2010 and july 7, 2010. among 102 datasets, 32 pairs of samples from 29 patients were simultaneously measured with both analyzers. we determined correlations between the differences in cl concentrations and ph, pco2, bicarbonate (hco3), and gag, which were defined as follows : gag = na(blood gas) cl(blood gas) hco3. we retrospectively collected data from patients who started maintenance dialysis therapy for esrd at our hospital between april 1, 2009 and june 30, 2010. among 45 cases, 37 pairs of samples from 37 patients taken at the start of dialysis were simultaneously measured by the blood gas analyzer and the central laboratory analyzer. we determined correlations between the differences in cl concentrations with hco3 concentrations and gag. among 32 pairs of samples used in the study of patients with severe acidemia, mmol / l, serum creatinine levels 7.40), whereas there were no statistically significant differences in na or k concentrations between these groups (table 1). to investigate the factor(s) associated with the differences in cl concentrations between acidic and alkalemic groups, we determined correlations between the difference in cl concentrations and several factors associated with the acid - base status (i.e., ph, pco2, gag, and hco3) in patients with severe acidemia. this analysis comprised 32 pairs of samples from 29 patients aged 70.0 15.5 years (21 males, 24 pairs of samples ; 8 females, 8 pairs of samples). the mean biochemical values were as follows : arterial ph, 7.01 0.16 (range, 6.657.20) ; paco2, 80.0 35.6 mmhg (25.8183.0 mmhg) ; hco3, 19.3 8.8 mmol / l (6.935.8 mmol / l) ; gag, 12.3 6.7 mmol / mmol / l) ; lactate, 8.7 7.2 mmol / l (0.320.9 mmol / l). in patients with severe acidemia, the difference in cl concentration was well correlated with the hco3 concentration (r = 0.72, p < 0.0001) (figure 1(a)). the difference also showed good correlations with gag (r = 0.69, p < 0.0001) (figure 1(b)), but weaker correlations with ph and pco2 (r = 0.40, p = 0.02 and r = 0.43, p = 0.01, resp.). to further explore the possible relationship between the difference in cl concentrations with hco3 concentrations and gag, we determined correlations using data from several types of high - ag acidosis. this analysis comprised 37 pairs of samples from 24 patients aged 70.3 16.3 years (17 males, 28 pairs of samples ; 7 females, 9 pairs of samples). the mean values were as follows : arterial ph, 7.31 0.08 (range, 7.077.48) ; paco2, 34.7 9.2 mmhg (13.754.9) ; hco3, 17.4 5.7 mmol / l (7.932.2) ; gag, 10.4 4.0 mmol / l (2.823.8) ; lactate, 0.9 0.3 mmol / l (0.81.7) ; bun, 96 35 mg / dl (38212) ; serum creatinine, 7.88 4.88 mg / dl (2.3730.61). in data from 37 patients with esrd, the differences in cl concentrations were correlated with hco3 concentrations (r = 0.66, p < 0.0001) but not with gags (r = 0.24, p = 0.16). the nine patients (8 males (89%) and 1 female (11%)) with lactic acidosis were 71.4 17.5 years, with one pair of samples from each patient. the mean biochemical values were as follows : arterial ph, 6.99 0.17 (range, 6.657.20) ; paco2, 74.9 36.0 mmhg (25.8146 mmhg) ; hco3, 16.4 4.8 mmol / l (8.121.6 mmol / l) ; gag, 14.0 4.3 mmol / l (8.818.9 mmol / l) ; lactate, 12.6 4.6 mmol / l (7.119.8 mmol / l) ; bun, 25.2 13.2 mg / dl (12.855.9 mg / dl) ; serum creatinine, 1.30 0.47 mg / dl (0.381.89 mg / dl) ; serum glucose, 143 62 mg / dl (47227 mg / dl). in these patients, the differences in cl concentrations were significantly correlated with hco3 (r = 0.80, p < 0.01) (figure 2(a)) and lactate concentrations (r = 0.73, p = 0.03) (figure 2(b)). in our experimental studies performed to understand the possible explanations for our findings, the addition of lithium lactate or kh2po4 did not affect the cl concentrations measured by both analyzers (table 2). in contrast, the addition of nahco3 proportionately increased the cl value measured by the hitachi7600 but not the cl value measured by the abl800flex (figure 3). the ph and pco2 values increased proportionately from 7.226 0.02 and 17.7 0.2 mmhg, respectively, at an hco3 concentration of 7.1 0.1 mmol / l to 7.964 0.01 and 36.0 0.2 mmhg, respectively, at an hco3 concentration of 90.3 0.3 clinically significant differences were found between ags calculated with electrolyte values measured with abl800flex and hitachi7600 for samples from patients with severe acidemia, esrd, and lactic acidosis (table 3). the present study revealed that there are clinically significant differences in cl concentrations measured using a central laboratory analyzer compared to those measured using a blood gas analyzer and that the differences were significantly correlated with hco3 concentrations and gags. the present study also revealed that hco3 concentrations are correlated with the cl concentrations measured by the central laboratory analyzer but not with those measured using the blood gas analyzer. however, the addition of lactate or po4 did not affect the cl concentrations measured by either analyzer. these findings suggest that the cl concentrations measured by some analyzers may significantly deviate from the real value in patients with severe acidosis or severe alkalosis, and these results may not be suitable for assessing a patient 's acid - base status, such as the ag or the cl deficit. recent studies have reported small but significant differences in electrolyte concentrations measured using a point - of - care analyzer and a central laboratory analyzer [37 ]. in these studies, the mean na [36 ] and k concentrations were higher, while the mean cl concentrations were lower when measured using a central laboratory analyzer compared with a blood gas analyzer [3, 6, 7 ]. whole - blood samples were used for the blood gas analyzer whereas serum samples were used for the central laboratory analyzer. the sample tubes used for the blood gas analyzer contained solid - phase heparin, which could bind the electrolytes, thereby lowering the electrolyte concentrations measured by the blood gas analyzer. the lower k concentrations determined using the blood gas analyzer in the present study may be explained by the use of an anticoagulant in the sample tubes used for the blood gas analyzer to prevent platelet rupture and the release of k into plasma. although these explanations could account for the lower na and k concentrations, they do not account for the higher cl concentrations measured with the blood gas analyzer. interestingly, the mean differences in cl concentrations between the two analyzers, but not na and k concentrations, were significantly different between samples from acidic patients and those from alkalemic patients. furthermore, the difference in cl concentrations between the two analyzers was significantly correlated with hco3 concentration and gag. these findings strongly suggest that the cl concentrations determined with either of the two analyzers are influenced by factor(s) associated with the acid - base status. the cl concentration is measured by an ion - selective electrode (ise) method [11, 12 ]. direct methods are usually used in blood gas analyzer, while indirect methods requiring predilution are used in central laboratory analyzer [6, 11 ]. errors in the cl concentration measured by the ise method have been reported in several conditions. first, indirect methods may underestimate the cl concentration because of dilution artifacts in patients with severe hypertriglyceridemia or dysproteinemia. this is unlikely to explain our findings, because the mean na concentrations measured by the central laboratory analyzer were higher than those measured by the blood gas analyzer. if dilution artifacts influenced the measurements, the na concentrations measured by the central laboratory analyzer should be lower, not higher, than those measured by the blood gas analyzer. second, because the selectivity of the ise method for cl could be influenced by other anions present in the sample, it may interfere with the measurement in cl concentration [11, 12 ]. the membranes of most currently used ises for cl contain an ion - exchanger, a quaternary ammonium chloride. hence, all ions that have hydration energy higher than or equivalent to cl are considered as potentially interfering ions. for example, cases of pseudohyperchloremia in patients with bromide (br) or iodide (i) intoxication have been reported [14, 15 ]. it is unsurprising that both the hco3 concentrations and the gags showed good correlations with the difference in cl concentrations in the present study because of an equimolar relationship between the hco3 concentration and the ag. these results suggest that hco3 or unmeasured anions such as lactate or po4, a major component of ag in patients with high ag acidosis, either alone or in combination, are responsible for the observed difference. in our experimental study, however, only the addition of hco3, a potential interfering ion, proportionately increased cl levels measured by the central laboratory analyzer (hitachi7600). this relationship indicates that hco3-mediated interference with the central laboratory analyzer may be responsible for the differences in cl concentrations between the two analyzers. therefore, the possibilities that ph and/or pco2 may explain the results of this clinical study can not be excluded. because of the performance of the ise and the composition of the calibration liquid as well as the calibrating system used in each analyzer, the degree of interference of potential interfering ions on cl measurement may vary among analyzers [13, 16, 17 ]. interestingly, two of the three central laboratory analyzers used in the studies that revealed statistically significant differences in cl concentrations between the two methods are products from the same manufacturer of equipment used in our study [3, 6 ]. in fact, hco3 interference with the ise from the manufacturer has already been reported [18, 19 ]. taken together, it seems reasonable to conclude that the measurement of cl concentrations using the central laboratory analyzer is influenced by hco3 levels. this interference will likely result in underestimation of cl concentrations in patients with metabolic acidosis and overestimation in patients with metabolic alkalosis, thereby overestimating and underestimating the ag and cl deficit, respectively. patients in whom calculation of the ag or cl deficit is needed are often critically ill, and precise measurement is required. for patients with severe acidosis or alkalosis, clinically significant deviation from the real value could occur, which may result in wrong treatment. therefore, the results may not apply to comparisons of other blood gas analyzers and central laboratory analyzers. however, the two analyzers under scrutiny are used by hundreds of laboratories in western countries, meaning our observations are very relevant to medical practice in many institutions. however, this is unlikely because we measured approximately 130 samples over 12 months, and the analyzers were checked daily and regularly inspected and tested for accreditation in accordance with japanese laboratory standards. both analyzers performed in accordance with the standards for the measurement of each analyte under study. third, the number of samples used in the four groups (icu, severe acidemia, esrd, and lactic acidosis) may not provide sufficient enough power to detect other contributing factors to the deviations in cl measurements other than hco3. similarly, the experimental studies could not exclude the possibilities that ph and/or pco2 may be explain the deviations observed. finally, because we selected specific groups of patients, the results and interpretations are subject to selection bias. nevertheless, our experimental study supports the notion that the acid - base status of a patient affects the degree of inaccuracy in cl measurements for some analyzers. in conclusion, our study revealed that the measurement of cl concentrations by some analyzers may be influenced by hco3 concentrations, which may account for the reported discrepancy between values measured by point - of - care and central laboratory analyzers. the deviation in cl concentration from the real value, particularly in patients with severe acidosis or alkalosis, could be clinically significant and may lead to incorrect interpretation of a patients ' acid - base status. clinicians, especially nephrologists who are specialists in the field of blood gas analysis, should be aware of potential deviations in cl concentrations measured by some analyzers. this is particularly important when cl concentrations are used to estimate a patient 's acid - base status. clinical and laboratory staff should be aware of this issue until they verify that this is not the case for the analyzers used at their institutions. | background. to address the cause(s) of the significant differences in chloride (cl) concentrations between point - of - care blood gas analyzers and central laboratory analyzers. methods. cl concentrations measured simultaneously by a blood gas analyzer (abl800 flex) and a central laboratory analyzer (hitachi7600) were collected in patients with severe acidemia (ph < 7.20) (n = 32) and were examined for correlations between differences in cl and factors associated with the acid - base status. cl concentrations were measured with both analyzers for samples with different concentrations of lactate, inorganic phosphate, or bicarbonate (hco3). results. the differences in cl concentrations were correlated with hco3 concentrations (r = 0.72, p < 0.0001) and anion gap (r = 0.69, p < 0.0001). only the addition of hco3 proportionately increased cl levels measured by a hitachi7600, but it did not affect those measured by an abl800flex. conclusion. cl measurements with some analyzers may be influenced by hco3 concentrations, which could result in the observed discrepancies. |
the definition of pain was established by the international association for the study of pain (iasp) in 1979 as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. newborns and infants are often exposed to numerous procedures during hospitalization which can be characterized as painful. in terms of requirements for pain perception, by 20 weeks gestation, the fetal neocortex is present, and pain pathways to the brain stem and thalamus are completely myelinated by 30 weeks. in addition, early exposure to pain has been shown to affect the way babies respond to pain later in life. it is, therefore, important for clinicians to assess and manage pain on a regular basis in order to avoid excessive exposure. several validated and reliable pain scales exist to measure acute pain in term and preterm neonates. these scales incorporate a combination of behavioral indicators of pain (e.g., facial expression, body movements, and crying) and/or physiological indicators of pain (e.g., changes in heart rate, respiratory rate, blood pressure, oxygen saturation [sao2 ], vagal tone, palmar sweating, and plasma cortisol or catecholamine levels) to assess pain in neonates. cries is a postoperative pain measurement score that includes crying, the requirement for oxygen supplementation (for sao2 > 95%), increases in heart rate and blood pressure, facial expression, and sleeplessness. the premature infant pain profile (pipp) is a seven - indicator composite measure that includes gestational age, behavioral state, heart rate, oxygen saturation, and facial actions (brow bulge, eye squeeze, and nasolabial furrow) [6, 7 ]. the neonatal infant pain scale (nips) is based solely on behavioral indicators of pain (facial expression, cry, breathing patterns, movements of arms and legs, and state of arousal). the neonatal facial coding system (nfcs) is a unidimensional measure that includes multiple indicators of facial expression and was developed for use in pain research [9, 10 ]. despite the number of pain measures that are available, no single scale can easily and accurately assess pain in all newborns and infants, especially in very low birth weight neonates or those who require mechanical ventilation. the objective of this study was to develop and validate a single pain scale (the covers scale) as a measure that can be used clinically to assess pain in newborns and infants regardless of their gestational ages and disease states. study participants were 21 newborn infants admitted to the neonatal intensive care unit at jacobi medical center. infants with congenital anomalies, severe neurological abnormalities or who had received pain medications within 12 hours of the evaluation were excluded from this study. informed parental consent was obtained, and the study was approved by the institutional review board. in order to be able to assess the needs of all infants, including the extremely low birth weight, sedated, and/or ventilated infants, the previously established scales were modified. the structure of the new scales incorporated many of the measures of previous scales but the measures were redefined, more descriptors were included, and a category called signaling distress was added. with these changes, the covers scale is based on six different physiological and behavioral measures, each with a possible score of 0, 1, or 2 for a maximum score ranging from 0 to 12. the physiological measures include changes in heart rate, blood pressure, and respiratory rate. the behavioral indicators include facial expression, resting state, body movements, and crying. newborns admitted to the neonatal intensive care unit at jacobi medical center were evaluated for pain during two procedures, a heel stick and a diaper change. all infants were eligible for the study, including those who were premature, very low birth weight, intubated, and/or recovering from surgery, provided they did not meet any exclusion criteria as cited above. the procedures used for measuring pain were all part of the infants ' routine hospital care and occurred within the same 12-hour period. a crossover design was used so that each patient included in the study was assessed during both procedures. a single observer rated pain at the patients ' bedside at three different time points : at baseline (before any handling or interventions had taken place), during the procedure (heel stick or diaper change), and after a recovery period (during which no handling or interventions had taken place). the pain responses were initially measured using a composite scale that incorporated indicators from the three previously established pain scales (cries, pipp, and nips) as well as the covers scale. the indicators were later separated and analyzed in accordance with their appropriate scales so that the covers scale could be compared to the already validated scales. to establish concurrent validity, scores on the covers scale were compared to the pipp and nips, for premature and full - term infants, respectively. to establish construct validity, pain scores were measured for 21 newborn infants, 57% male, 080 (mean 22.6) days old, with gestational age ranging from 2740 (mean 34.9) weeks. of the 21 newborn infants included in the study, 13 were premature (< 37 weeks) and 8 were full term. demographic data for the patients is included in table 2. in order to establish concurrent validity, the covers scale scores for the premature infants were compared to the pipp scores, while those for the full - term infants were compared to the nips scores. for the premature infants, the covers scale and pipp scale resulted in similar pain scores with an r = 0.84 (table 3, figure 1). for the full - term infants, the covers scale and nips scale resulted in similar pain scores with an r = 0.95 (table 4, figure 2). in order to establish construct validity, the covers scores for the painful heel stick procedure were compared to those for the nonpainful diaper change procedure (table 5, figure 3). there was no significant difference between the pain scores at baseline for the heel stick (range 03, mean 0.1) and diaper change (range 02, mean 0.4). during both procedures, the pain score had a significant increase from baseline (p <.05). for the heel stick, the scores ranged from 112 with a mean of 7.3. for the diaper change, the scores ranged from 010 with a mean of 4.9. in addition, the pain rating during the heel stick was significantly greater than during the diaper change (p <.05). after the recovery period, there was a significant decrease in the mean pain score for both procedures (p <.05). however, there was no significant difference between the pain scores after recovery for the heel stick (range 05, mean 1.3) and diaper change (range 08, mean 2.0). the results of this study demonstrate that the covers scale is a valid pain scale that can be used in the clinical setting to assess pain in newborns and infants. concurrent validity is defined as the extent to which a test yields the same results as other measures of the same phenomenon. concurrent validity was established by comparing the covers scale to previously validated pain scales, namely the pipp and nips, and demonstrating a high degree of correlation. construct validity is defined as the extent to which a test measures what it is intended to measure. construct validity was established by comparing the pain scores on the covers scale during a the covers scale is an easy - to - use scale that addresses pain assessment in a broad range of newborn infants. the cries scale (though noted for its ease of use) has limited usefulness in measuring pain in the intubated, paralyzed, or extremely premature infant. the pipp is best suited for preterm infants, has some subjectivity, and is complicated to score. the nips does not include any physiological parameters (hr, bp, and o2 requirement) which are often early indicators of pain and/or distress in premature, sedated, or paralyzed infants. research has shown that neonates react to pain with a combination of behavioral and physiologic responses. similar to other previously validated pain scales, the covers scale is multidimensional and thus incorporates these responses. the unique feature of the covers scale is that the criteria used for scoring are applicable to a wider range of infants. high - pitched crying is one of the behavioral responses to pain, but an intubated infant physically can not make such a cry, which creates a dilemma for the caregiver assessing pain. the covers scale takes this into account by including visible crying as a behavioral response. the scale also addresses oxygen requirements from a new perspective. rather than recording the infant 's oxygen requirement, which is not always indicative of pain, it looks at a change in the need for oxygen. this increases the covers scale applicability to infants who may be intubated or on supplemental oxygen at baseline. one limitation that the covers scale does have is that it can not be used to assess paralyzed infants since they can not perform behavioral responses such as crying, grimacing, or signaling distress. however, the scale also incorporates physiological responses that would still apply to paralyzed infants. another important aspect of a pain scale is its acceptability to the medical staff that will be using it. it has already been shown that cries was well accepted and in fact preferred by nurses. the covers scale retained much of the ease of use of the cries, and should also be well received in clinical situations. further study is necessary to determine if the covers scale is perceived as easy to use as well as to validate interrater reliability and applicability to infants beyond the newborn period. this paper has demonstrated that the covers scale has both concurrent and construct validity and is thus a valid pain scale that can be used in the clinical setting to assess pain in newborns and infants. in comparison to other previously validated pain scales, the covers scale has the clinical advantage of being universally applicable to all neonates, regardless of their age or physiological state. this includes infants who are premature, very low birth weight, intubated, and/or recovering from surgery. it is well established that neonates perceive, respond to, and remember pain. it is, therefore, essential that pain be assessed and managed in this patient population. with the use of the covers scale, medical and nursing staff can gain a better grasp of the pain and discomforts their patients are experiencing as well as means to verify that attempts at managing pain in this population are successful. | newborns and infants are often exposed to painful procedures during hospitalization. several different scales have been validated to assess pain in specific populations of pediatric patients, but no single scale can easily and accurately assess pain in all newborns and infants regardless of gestational age and disease state. a new pain scale was developed, the covers scale, which incorporates 6 physiological and behavioral measures for scoring. newborns admitted to the neonatal intensive care unit or well baby nursery were evaluated for pain / discomfort during two procedures, a heel prick and a diaper change. pain was assessed using indicators from three previously established scales (cries, the premature infant pain profile, and the neonatal infant pain scale), as well as the covers scale, depending upon gestational age. premature infant testing resulted in similar pain assessments using the covers and pipp scales with an r = 0.84. for the full - term infants, the covers scale and nips scale resulted in similar pain assessments with an r = 0.95. the covers scale is a valid pain scale that can be used in the clinical setting to assess pain in newborns and infants and is universally applicable to all neonates, regardless of their age or physiological state. |
the function of sex steroid hormone receptors in breast cancer has been extensively studied and applied to diagnosis and treatment [1, 2 ]. estrogen stimulates cell proliferation of breast epithelial cells, and the close relationship between the expression of estrogen receptor (er) and the prognosis of breast cancer has been well characterized. progesterone levels fluctuate during the menstrual cycle and regulate cell proliferation and differentiation ; however, less is known regarding its role in breast cancer [46 ]. we have previously identified that introducing progesterone receptor (pr) into hormone - independent breast cancer cells significantly suppressed their proliferative and invasive activities upon progesterone treatment. several drugs such as tamoxifen, an estrogen receptor antagonist, as well as a synthetic progestin similar to progesterone, are considered to be effective at inhibiting tumor cell proliferation. these drugs are given as adjuvant therapies in breast cancer patients when greater than 10% of the breast cancer cells express er or pr receptors as assessed by immunohistochemical staining of the tumor tissue [8, 9 ]. molecular targeted drug therapy is generally defined as less toxic than traditional chemotherapy ; however, some studies have reported severe side effects, and carefully designed and regulated clinical trials are necessary to confirm the safety. moreover, these types of therapies are not viable when a tumor expresses a low level of a molecular target, for example, a receptor. this problem is exemplified in breast cancers which do not express er, pr, or her2 receptors, that is, triple negative cases. in this patient population, it is a challenge for clinicians to provide efficacious treatments. sex steroid hormone therapy in prostate cancers is based on their high sensitivity to androgen inhibition. the most common hormone therapy is initiated by reducing the concentration of circulating androgens through surgical or medical castration and/or by administering antiandrogens such as flutamide or bicalutamide [11, 12 ]. however, in almost all patients, the efficacy of the treatment decreases over time as the tumor becomes androgen refractory. as a result, these patients develop distant metastases, such as in bone, which eventually is fatal to the patient. the molecular events, therefore, which control the transition from androgen - sensitive prostate cancer to androgen - refractory prostate cancer need to be elucidated. accumulating evidence suggests that the androgen receptor (ar) plays a critical role in regulating the growth of both androgen - sensitive and androgen - refractory prostate cancer [1419 ]. in addition, recent studies showed that the ar can regulate invasion and metastasis. in ar - negative cell lines such as pc3 and du145, it has been shown that forced ar expression decreased invasive properties and treatment with androgen further reduced invasion of these cells [21, 22 ]. moreover, it was reported that hormone refractory prostate cancers demonstrated a variety of ar alterations that were either not found in hormone nave tumors or found at lower frequency. a more recent investigation has demonstrated that forced expression of ar, in a subline of a metastatic androgen - dependent prostate cancer cell line, led to increased invasion. it is clear that a more detailed understanding of the ar alterations in the evolution of androgen - refractory prostate cancer is needed to help drive the development of potential new therapies. regarding the potential applications of hormone therapies against other cancers, some studies in ovarian and colon cancer have been described. in ovarian cancer, the use of estrogen as a menopausal therapy has frequently been associated with an increased risk of ovarian cancer, and there is still conflicting evidence on the impact hormone therapy has on decreasing the risk of cancer. a recent study, however, suggests that this problem can be circumvented by coadministering progestin and estrogen. further, experiments in culture showed that progesterone reduced proliferation of both benign and malignant ovarian tumor cells. therefore, progestin might be a key factor to prevent and suppress ovarian cancer cell growth. in contrast to ovarian cancer, estrogen appears to have protective effects against colon cancer. however, the role of hormone replacement therapy involving estrogen for treatment of colon cancer is poorly understood, and further analyses are needed. mammary and salivary glands are tubuloacinar exocrine glands and share similar morphological characteristics. comparing the tumors arising from these two different sites, similar histological features although the cancers differ in incidence and clinical behavior, certain biological features identified in both entities have been described, and potential common therapeutic approaches have been considered. the who classification of msgts represents more than twenty different histological subtypes [32, 33 ]. the majority of them are divided into two groups, the secretory duct origin (including mucoepidermoid carcinoma (mec) and salivary duct carcinoma (sdc)) and the intercalated origin type (including adenoid cystic carcinoma (acc)) [34, 35 ]. most of these tumors occur in the parotid gland (70%), and less than 25% are malignant. although the incidence of tumors at other sites, such as submandibular, sublingual, and minor salivary glands, is less common, the proportion of malignancy is higher, approximating 50%. most of aggressive breast cancers are composed of invasive ductal carcinoma, and other histologic features such as mec and acc are relatively rare. below, we briefly describe some of the types of msgts that display common features (at the morphological and molecular levels) with breast cancers and, therefore, could provide potential common therapeutic strategies. mec is the most common salivary gland neoplasm, accounting for 2934% of all malignancies of the major and minor salivary glands. the cell types are classified histologically as low, intermediate, and high grade, and 5-year overall survival (os) varies from 92% to 100% in low - grade tumors, 62% to 92% in intermediate - grade tumors, and 0% to 43% in high - grade tumors. high - grade mec is an aggressive malignancy, characterized by high rate of local recurrence and distant metastasis. on the contrary on the other hand, mec of breast is a rare entity with an estimated incidence of 0.2% and is composed of a mixture of basaloid, intermediate, epidermoid, and mucinous cells [30, 38 ]. since patchefsky. first described breast mec in 1979, only 28 cases have been reported [3853 ]. however, it was described that mecs deriving from breast and salivary glands share similar biological features and morphologies. they classified breast mecs into three grades using the same grading system as for the salivary gland tumors and demonstrated that high - grade tumors show high mortality resulting from lymph node and distant metastasis. these results suggest that mecs from both mammary and salivary glands, having similar morphological features, could have similar treatment strategies. further, a common cytogenetic alteration of breast and salivary mecs has been reported. a reciprocal translocation t(11;19)(q21;p13) (maml2:mect) was shown in breast mec, which is known as the most frequent genetic alteration of salivary gland counterparts. this translocation creates a fusion product (maml2:mect1) that activates transcription of camp / creb target genes [54, 55 ]. another report described that the expression of the protein fusion gene was associated with a significantly lower risk of death compared to those without the fusion protein maml2:mect1. it has also been shown that other subtypes of breast cancers are negative for this gene, suggesting that this fusion gene is specific to mec. this translocation is likely to be a promising marker for mecs from both breast and salivary gland. there are three histological subtypes : tubular, cribriform, and solid [29, 59 ]. in contrast to squamous cell carcinomas that account for the vast majority of head and neck malignancies, acc often spreads systemically, especially to lung and bone, and the metastatic proportion of this type of neoplasm represents 2455%. due to the high metastatic rate the 10-year os is 3955%, and 20-year os is 2125%. on the other hand, breast acc is a rare malignancy, accounting for 0.11% of all breast cancers. in addition, these neoplasms show different clinical behaviors than their salivary gland counterparts. 10-year os represents more than 90%, and lymph node and distant metastases are generally rare. however, the histological features of breast accs are very similar to accs originating from salivary glands (as shown in figure 1). ro. applied the same grading system to accs from both types of tissues, and breast and salivary gland tumors are characterized by expression of c - kit and share a common chromosomal translocation t(6;9) leading to the fusion gene myb - nfib [31, 61, 62 ]. c - kit has been shown to be expressed in 80100% of accs of salivary gland and in almost all accs from the breast [6370 ]. the genetic alteration t(6;9)(q22 - 23;p23 - 24) was first identified as a characteristic for salivary gland accs. the fusion gene is highly expressed in proliferating cells and is downregulated, as the cells become more differentiated. sdc is a rare and highly aggressive neoplasm representing close histologic features with invasive ductal carcinoma of the breast (idc) [28, 72, 73 ]. the epithelium tends to form cribriform, papillary, and solid growth patterns along with the duct - like structures. the morphology of sdc is characterized by cuboidal and polygonal cells forming distended ducts and solid nests (often with central necrosis) and which are very similar to comedo carcinomas of the breast. in addition to the histopathological resemblance, both entities have similar clinical behaviors ; that is, they have highly metastatic features leading to poor prognosis. a wide variety of molecular studies have been performed and led to the identification of certain biological markers for sdcs. among them is her-2, which is amplified in 2025% of breast cancers [74, 75 ]. various studies of her-2 in sdc have shown variable results, with amplification ranging between 25% and 100% of the tumors. nonetheless, the proportion is much higher than in other histological subtypes such as accs and mecs described above [8, 28, 32, 36, 7784 ]. her-2 expression is considered to correlate with histological grades in both salivary gland neoplasms as well as breast cancer, and it represents a potential attractive therapeutic approach for sdcs. as her-2 can also enhance ar function, antiandrogen therapy may be effective against msgts when her-2 is overexpressed. previous studies have described that high egfr expression in sdcs may contribute to tumor growth [78, 85 ]. egfr has been shown to enhance tumorigenesis in several human carcinomas by blocking apoptosis and promoting angiogenesis. regarding both egfr and her-2, the interaction with hormonal pathways has also been described. in the breast and uterus cancers, treatment with anti - egf antibodies reduced tumor proliferation induced by treatment with estradiol. likewise, the antiestrogen ici 164,384 reduced the effects of egf - induced tumor proliferation. hoang. performed molecular studies, using microsatellite markers and dna flow cytometry, and compared the biological characteristics underlying sdc and idc. they determined that there were similar allelic alterations on chromosomal arms 6q, 16q, 17p and 17q, and that dna aneuploidy in both malignancies may contribute to their aggressive behavior. recently, it was determined that polysomy of chromosome 7 was detected in 25% of sdcs and this alteration correlated with poor os. this correlation was also reported in idcs and supported the notion that egfr gene mutations may guide therapy. taken together, gene alterations of both egfr and her-2 may define molecular features of these two types of malignancies, and these receptors may be candidates for targeted therapy. as described above, several types of msgts are morphologically and biologically similar to malignant breast cancers [29, 91 ] (figure 1). further, the clinical significance of sex hormone receptors has been debated since white and garcelon first described therapy with estrogen against salivary gland neoplasms in 1955. previous reports obtained using a low number of biopsy samples have shown conflicting results regarding the expression of sex hormone receptors, making difficult to determine the potential benefits of hormone therapy [93103 ]. therefore, additional studies are required in order to clarify the role of hormone receptors in msgts. although several studies examined er and pr expression in msgts, there is substantial disparity in the results : the expression of er and pr can vary between 086% and 050%, respectively [93103 ]. this disparity may be explained by differences in antibodies used, experimental methods for detection (e.g., western blotting versus immunohistochemistry), and the criteria used to rule out false positives and negatives. it is, therefore, particularly critical to standardize protocols (such as for the ihc) similar to that described for the analysis of breast cancer tissues. in addition, some of the differences might result from insufficient number of samples available. even though er expression is unlikely to represent a useful marker for detecting msgts, a subset of msgts clearly expresses hormone receptors, and these receptors could control disease progression. thus, current therapeutic strategies used in breast cancer patients may also be effective for the treatment of msgts. moreover, the feasibility of hormone therapy seems to be supported by the accumulating reports of ar expression in sdcs. although the expression of ar is generally rare in salivary gland neoplasms, sdcs commonly express ar in 92100% of the cases [85, 104, 105 ]. recently, jaspers. reported that androgen deprivation therapy (adt) in patients with recurrent or disseminated disease showed a clinical benefit in five out of ten cases, and two of them had partial responses. this approach is, therefore, more effective than the results obtained after the use of chemotherapy. given the fact that adt has generally less adverse effects than chemotherapy, antiandrogen therapy may lead to better clinical outcome and become a standard treatment method for sdcs. described that most tumors derived from breast and salivary glands expressed estrogen receptor - beta (er-) and that the patients whose tumors lacked er- were at higher risk for local recurrence. in addition, previous studies have linked the loss of er expression to aggressive features in adenocarcinomas from breast, prostate, and colon [106111 ]. in breast and prostate carcinoma, er- has been shown to inhibit cell proliferation by cyclin d1 pathway and to induce apoptosis by downregulating bcl-2 and/or inducing bax expression [112, 113 ]. targeting er- may, therefore, become a useful approach for the management of salivary duct carcinoma. in our previous studies, we determined that msgts cell lines in culture lacked estrogen and progesterone receptors. however, lack of hormone receptors may be a consequence of malignant transformation and may represent a requirement for the establishment of immortal cell lines. studies have reported the efficacy of tamoxifen against msgts in patients [114, 115 ], and one of them showed a long - term survival even though er was not detected by immunohistochemistry. this result appears to be supported by another case report, where tamoxifen could reactivate er expression. our previous studies showed that progesterone could suppress mgst cell aggressiveness similarly to that observed in breast cancer cells (figure 2). specifically, we demonstrated that after transduction of pr, progesterone could significantly suppress proliferation (and invasion) of msgt cells. this suppression did not lead to cell death but to cell - cycle arrest. these data suggest that if msgts express significant levels of pr, then progesterone treatment may slow the growth of the primary tumor and potentially shift it to a dormant state. since most msgts occur in older age patients, triggering tumor dormancy could improve quality of life and may be a successful way to allow the patient a normal lifespan. although 5-year os in patients with msgts represents the average, extended survival rates are extremely low [118120 ]. msgts show low sensitivity to chemotherapy and surgery because of anatomical limitations [121, 122 ]. triggering tumor dormancy as a consequence of hormone therapy would represent a novel strategy for the treatment of patients with msgts. besides surgical resection and radiation of msgts, there are no other effective therapies. adjuvant therapy is generally reserved for palliative treatment ; however, there is no clear evidence that such treatment can bring clinical benefits. since adverse effects caused by chemotherapy often threaten the life of a patient, and since some patients with specific msgts, especially accs, show long survival even with multiple metastases, the adoption of adjuvant therapy should be carefully considered. to achieve new therapeutic methods, it is now necessary to clarify several unanswered questions such as the expression and/or function of sex steroid hormone receptors in msgts. as indicated by ar expression in sdcs, there is now evidence linking hormone receptors and growth factor receptors to the disease.. however, to improve clinical outcome with rather rare malignancies, more accurate data obtained from multiple and larger studies are required. msgts tend to occur in older age patients, and triggering tumor dormancy could be a successful way to slow down their disease progression, therefore providing an improvement in their quality of life. our studies in pr - negative cells also suggest that the induction of hormone receptor gene expression might be an option for delaying disease progression. based on multiple lines of evidence from a range of cancers, sex steroid hormone receptors may prove to be appropriate targets for the establishment of novel treatments for patients with msgts. | malignant salivary gland tumors (msgts) account for 26% of all head and neck cancers. despite the rarity, msgts have been of great interest due to a wide variety of pathological features and high metastasis rates resulting in poor prognosis. surgical resection followed by radiation therapy represents the main treatment of this malignancy. adjuvant therapy is reserved for the management of local recurrence, no longer amenable to additional local therapy, and for metastasis. based on the studies from other types of tumors, particularly breast cancer, the expression and function of sex steroid hormone receptors in cancer have been extensively studied and applied to diagnosis and treatment. although a number of studies in msgts have been published, the rationale for hormone therapy is still controversial due to the disparate results and insufficient number of cases. however, some recent reports have demonstrated that certain salivary gland neoplasms are similar to breast cancer, not only in terms of the pathological features, but also at the molecular level. here, we shed light on the biological similarity between msgts and certain types of breast cancer, and describe the potential use of hormone and additional therapies for msgts. |
since the introduction of laparoscopic hernia repair by schultz in 1990, surgeons have compared this new technique to the traditional repairs of mcvay, bassini, shouldice and lichtenstein. the endoscopic preperitoneal herniorrhaphy, which is based on the established open preperitoneal techniques of stoppa, nyhus, wantz and others, is becoming increasingly accepted as the best laparoscopic technique for repair of groin hernias. bilateral inguinal hernia repair is rarely performed during traditional open herniorrhaphy. on the other hand, one widely accepted indication for the performance of endoscopic preperitoneal herniorrhaphy is the presence of bilateral hernias. to our knowledge, no prior studies have compared the recovery following unilateral and bilateral endoscopic preperitoneal hernia repairs. presented herein is a study comparing intraoperative and postoperative data for patients undergoing endoscopic herniorrhaphy for either unilateral or bilateral hernias. from july 15, 1994 to august 16, 1996, a total of 250 patients underwent repair of 373 hernias by a single surgeon (als) in a teaching setting. one hundred twenty - seven patients underwent unilateral hernia repair (uh), while 123 patients underwent bilateral hernia repair (bh). the male : female ratio was 114:13 for uh and 121:2 for bh (p>0.05). mean age was 56 for uh (range 18 - 89) and 53 for bh (range 1886) (p > 0.05). type of anesthesia used and the percentage of virgin and recurrent hernias were likewise similar for the two groups (table 2). (note : all patients presenting with recurrent hernias had previously undergone open hernia repairs.) postoperative patient survey. patients were asked to record responses to the following three criteria on the day of surgery as well as postoperative days 1, 2, 3, 7, 14, and 28. they were also asked to record the date of return to work and/or full normal activity, (note : notations in parentheses are legends for figures 17) patient demographics. preoperative antibiotics prophylaxis consisted of a single dose of cefazolin (1 g) or vancomycin (500 mg). the preperitoneal space was created with the use of a preperitoneal distension balloon (pdb, origin medsystems, menlo park, ca) and was maintained with co2 insufflation at a pressure of 12 mm mercury. for all hernia repairs, dissection was carried out to identify and/or expose cooper 's ligament, the inferior epigastric vessels, the internal ring, the spermatic cord and the iliofemoral vessels. a single sheet of polypropylene mesh was used to repair each hernia in this series (size range of 3 x 5 to 4 x 6 inches). a keyhole incision was created superiolaterally in the mesh to allow the mesh to wrap around the cord, thus recreating the internal ring. the mesh was fixed to the anterior abdominal wall and cooper 's ligament using either the endoscopic multifire stapler (ems, ethicon endo - surgery, cincinnati, oh) or origin tacker (origin medsystems, menlo park, ca). no mechanical fixation of the mesh was performed below the iliopubic tract except at cooper 's ligament. at the completion of the repair(s), 30 cc of 0.25% bupivacaine with epinephrine (1:100,000) were placed into the preperitoneal space for the purpose of postoperative analgesia. postoperative pain control was managed with oral acetaminophen with codeine (tylenol # 3) in all patients. at the time of discharge, all patients were sent home with a postoperative questionnaire. they were asked to qualitate their level of pain as well as keep track of their level of activity and number of narcotic analgesic pills ingested. patients were asked to log these criteria on the day of surgery as well as postoperative days 1, 2, 3, 7, 14 and 28. patients were also asked to record their return to work or, if retired or unemployed, when they were able to resume full " normal " activity (table 1). initially, patients were asked to mail these forms back to the surgeon 's office upon completion of the survey. with these response rates less than 100 percent, the forms were collected and discussed at the first postoperative visit (at 2 - 3 weeks postop) if the patients had returned to full activity. statistical methods included t - test, chi - square test and mann - whitney rank sum test. intraoperative data are summarized in table 3 although operative time was longer in the bilateral group (65 vs. 43 minutes ; p 0.05). all hernia repairs were successfully completed endoscopically, with no conversions to open technique required. postoperative surveys were collected through mail follow - up or at the time of the first postoperative visit. response rates for the two groups were similar (81/127 (64%) for uh and 81/123 (66%) for bh ; p > 0.05). the legend for these figures is given in table 1 (i.e., p0, p1,...,n0, n1,... (note : legend for figure is in table 1.) postoperative data for endoscopic herniorrhaphy on postoperative day # 1. (note : legend for figure is in table 1.) postoperative data for endoscopic herniorrhaphy on postoperative day # 3. (note : legend for figure is in table 1.) postoperative data for endoscopic herniorrhaphy on postoperative day # 7. (note : legend for figure is in table 1.) postoperative data for endoscopic herniorrhaphy on postoperative day # 14. (note : legend for figure is in table 1.) postoperative data for endocopic herniorrhaphy on postoperative day # 28. no significant differences for perception of pain, narcotic use or level of activity were noted on any of the days measured (p > 0.05 for all comparisons on all days). the unilateral group returned to work / normal activity at 6.32 + /3.29 days and bilateral group returned to work / normal activity at 6.68 + / 4.13 days (p>0.05). one of the more established indications for the performance of endoscopic preperitoneal herniorrhaphy is the presence of bilateral hernias, yet no prior studies have compared postoperative recovery following unilateral and bilateral endoscopic herniorrhaphy. the majority of these studies have focused on transabdominal laparoscopic techniques. in order to evaluate the postoperative course of patients undergoing groin herniorrhaphy, a survey was designed. this survey assesses patient recovery based on a qualitative measure of pain, a quantitative record of narcotic use, and a record of day - to - day activity. this study shows for the first time that the recovery following endoscopic preperitoneal herniorrhaphy is the same for patients with unilateral and bilateral hernias. no differences existed for perception of pain, narcotics used, or level of activity on any of the days analyzed. the addition of a contralateral hernia repair during the performance of an endoscopic preperitoneal herniorrhaphy is well tolerated by patients. this is likely due to the small increase in operative time, as well as the minimal additional dissection needed to expose the inguinal anatomy on the second side. bilateral herniorrhaphy can be performed without the need for additional trocar placement or repeat balloon dissection of the preperitoneal space. the tension free onlay of a second piece of polypropylene mesh apparently adds little to the postoperative symptom complex. our experience demonstrates that bilateral endoscopic preperitoneal herniorrhaphy can be performed with the same expected patient recovery as unilateral repair. | introduction : the advantage of using minimally invasive techniques over open techniques in the repair of inguinal hernias remains unclear. one of the more established indications for the performance of minimally invasive (e.g. endoscopic preperitoneal) herniorrhaphy is the presence of bilateral hernias. however, no prior study has compared the recovery following unilateral and bilateral endoscopic preperitoneal hernia repairs.patients and methods : from july 15, 1994 through august 16, 1996 one primary surgeon performed 373 hernia repairs on 250 patients. unilateral herniorrhaphy (uh) was performed on 114 males and 13 females with an average age of 58 (range 1889). bilateral herniorrhaphy (bh) was performed on 121 males and 2 females with an average age of 53 (range 18 86) (p>0.05). within the uh group there were 105 virgin hernias and 22 recurrent hernias. the bh group included 212 virgin hernias and 34 recurrent (p>0.05).bilateral repairs took longer to perform than unilateral repairs (65 minutes vs. 45 minutes) (p0.05). in addition, both groups returned to work at a similar time (uh : 6.32 + /3.29 days, bh : 6.68 + / 4.13 days) (p>0.05).conclusion : bilateral endoscopic preperitoneal herniorrhaphy can be performed with the same expected patient recovery as unilateral repairs. |
some of the previous reports have described the phenomenon of delusion of pregnancy in the context of antipsychotic - associated hyperprolactinemia and metabolic syndrome. in this case report, we present a case of pseudocyesis with delusional belief of being pregnant developing in the background of increased prolactin levels and metabolic syndrome associated with use of antipsychotics and expand the limited literature on this topic. x, a 46-year - old woman presented with an acute onset illness, continuous in course of 2-month duration, which started about 2 months after the death of her only son in a road traffic accident, characterized by liability of effect, delusion of persecution, visual hallucinations, regressed behavior, restlessness, irritability, disorganized behavior, muttering to self, decreased sleep, decreased appetite and poor self - care. there was no history of first rank symptoms, grandiosity, core depressive symptoms, any substance abuse, head injury, seizures, loss of consciousness and cognitive disturbances. there was no family history of mental illness, and premorbidly the patient had histrionic traits. initially, a diagnosis of acute and transient psychotic disorder (acute polymorphic psychotic disorder without symptoms of schizophrenia) (as per icd-10) was considered and she was started on risperidone up to 3 mg / day, but her condition kept worsening resulting in hospitalization. at the initial evaluation her weight was 83 kilograms, height was 158 cm and waist circumference was 102.5 cm. routine investigations and computed tomography of the brain did not reveal any abnormality. in view of non - response to 4 weeks of therapy, risperidone was stopped and she was started on olanzapine up to 20 mg / day, with which she initially showed response, and was discharged after 5 weeks. however, within 2 weeks she had worsening of symptoms leading to re - admission. due to the florid symptoms, she was started on electroconvulsive therapy and antipsychotic was changed to trifluperazine 15 mg / day. a diagnostic possibility of psychosis (not otherwise specified) (as per icd-10) was considered. her psychotic symptoms stabilized with trifluperazine and ect, but she developed depressive symptoms after stoppage of ect, amounting to moderate depressive episode without somatic features (as per icd-10) and required treatment with sertraline 100 mg / day. with this combination she remained well for 14 months. although she did not achieve her premorbid self, her residual negative symptoms did not interfere much with her level of functioning. during the stable phase, her body weight, waist circumference, lipid profile and fasting blood sugar levels remained stable. however, initially reported irregular menstrual cycles and later developed amenorrhea and galactorrhea on investigation was found to have significant increase in serum prolactin levels (150 ng / ml). tab trifluperazine was crossed tapered with tab quetiapine, which was increased to 300 mg / day. with starting of quetiapine, she started gaining weight and her waist circumference increased significantly. while cross - tapering was being done, she started having relapse of symptoms of psychosis. the symptoms kept on worsening despite increase in the dose of quetiapine to 600 mg / day along with clonazepam 6 mg / day with good compliance. the symptomatology of the current episode was very similar to the previous episode, but additionally she had delusion of pregnancy. she reported that she is pregnant, is able to perceive the movements of the fetus and is shortly going to deliver a male child. when anybody tried to tell her against the same, she would become irritable and violent. she held the belief of being pregnant firmly and could not be convinced against the same. while in the hospital at times she reported pain in the abdomen and would say that she was having labor pain and is going to give birth to a male child. she would also go to pass urine frequently, would demand for healthy food traditionally given to pregnant mothers and would walk by protruding her abdomen. at this time, her body weight was 96 kilograms and waist circumference was 138 cm. ultrasound abdomen revealed bulky uterus with multiple fibroids with no fetal sac and repeat serum prolactin levels were 89.5 ng / ml and 76.55 ng / ml on 2 different occasions 2 weeks apart. all other investigations including urine pregnancy test, thyroid function test and serum cortisol levels were done in consultation with the gynecologist and endocrinologist, which were found to be within normal limits. during the hospital stay, she very firmly held the belief that she is pregnant even though she had her menstrual periods. she was initially managed with tab ziprasidone up to 120 mg / day along with electroconvulsive therapy. although she showed some improvement in her positive symptoms with this treatment, delusion of pregnancy persisted at the same intensity. increase in dose of ziprasidone to 140 mg / day led to changes in the electrocardiogram and resultantly it was stopped. after giving all the available options, patient 's husband opted for clozapine. after proper evaluation, she was started on clozapine and the dose was gradually increased to 200 mg / day, with which she achieved remission with no further increase in body weight and waist circumference over the period of 12 weeks of therapy. pseudocyesis must be distinguished from closely related phenomenon of delusion of pregnancy, pseudo - pregnancy, simulated pregnancy and couvades syndrome. a person with delusion of pregnancy tends to believe that she is expecting a child, but this belief is not associated with bodily changes associated with pregnancy. it is suggested that delusional belief of being pregnant in females is usually labeled as pseudocyesis because of presence of physical signs and symptoms related to pregnancy accompanying the belief. in a review of literature, some authors have suggested that there are certain similarities and differences between delusions of pregnancy and pseudocyesis. similarities between the 2 phenomena include presence of features like amenorrhea, galactorrhea, breast engorgement and possibly elevated prolactin. in terms of differences, pseudocyesis is more frequently associated with features like abdominal distention, fetal movements, weight gain, nausea, vomiting and change in appetite. further, pseudocyesis is usually associated with endocrine abnormalities including elevated prolactin levels whereas a delusion of pregnancy is not associated with specific endocrine changes. pseudopregnancy is a bodily state that resembles pregnancy and is triggered by organic factors like endocrinopathies due to various reasons. a woman is considered to have simulated pregnancy when she admits to be pregnant, although she is aware that it is not true. couvades syndrome is seen in males, during or after the birth of a child in their family. in this state, the behavior of the male resembles a pregnant woman, although he knows that he is not pregnant. index case had hyperprolactinemia associated with amenorrhea, galactorrhea, weight gain leading to increase in the girth of abdomen. further, other associated behaviors included presence of fetal movements and presence of labor pains. the delusional belief of being pregnant in this context could be labeled as pseudocyesis. the delusional belief also had psychological significance taking the death anniversary of the son into consideration. if we take the weight gain into consideration and its temporal correlation with development of pseudocyesis, along with lipid profile disturbances, manifestations in the index case are akin to the description of delusion of pregnancy associated with antipsychotic - induced metabolic syndrome with clozapine as described in a case report. in the narration of the case, authors also described the sense of fetal movements and concluded that the patient had pseudocyesis. if the association of pseudocyesis and rise in prolactin level is taken into consideration, manifestations of our case are similar to the description of delusion of pregnancy associated with antipsychotic - induced increased prolactin levels. however, cases in one of these series only had delusion of pregnancy without associated signs and symptoms of pregnancy. in the second series, which included 6 women, the delusion of pregnancy was accompanied by a feeling of being pregnant in the form of abdominal distension and presence of visceral sensation of being pregnant. as described in both the case series, delusion of pregnancy in the index case also disappeared along with normalization of prolactin levels. the mechanisms like cognitive theory, physical state experiences and information processing vulnerabilities have been used to understand the development of delusion of pregnancy in the context of hyperprolactinemia and these have been discussed in detail by ahuja. our case adds to the limited literature on the phenomenon of pseudocyesis temporally related to development of hyperprolactinemia, obesity and metabolic syndrome. | pseudocyesis or phantom pregnancy is characterized by a false belief in a non - pregnant female that she is pregnant and this belief is usually associated with bodily signs of pregnancy. in some of the patients, this belief is held with delusional conviction. in this case report, we present the case of a female patient who presented with delusional belief of being pregnant, which was associated with antipsychotic - associated increase in prolactin levels and metabolic syndrome. |
esophageal atresia (ea), a rare congenital anomaly, occurs as an isolated entity or in association with tracheoesophageal fistula (tef).1 depending on the size of gap between esophageal ends, ea is divided into short - gap and long - gap ea. the latter, accounting for 10% to 31% of ea cases, is described by a significant gap between the esophageal ends, making repair more aggressive.2,3 the gap length not only determines the type of surgical management, but also is a prognostic indicator of mortality and morbidity in ea patients.2,4 however, long - gap ea is often identified in the course of thoracotomy and may pose further unexpected challenges for operating surgeons.5 therefore, predicting the presence of long - gap ea prior to the surgery seems to be of utmost importance. the embryologic defects leading to ea are associated with varying components of the malformation association termed vacterl.6 vacterl association describes vertebral defects, anorectal malformation, cardiac anomalies, tef and/or ea, renal anomalies, and limb defects.7,8 although controversial, some authorities attributed specific congenital anomalies to the presence of long - gap ea. canty first indicated that aortic arch anomalies were associated with long - gap ea / tef.9 moreover, although not statistically investigated, kulkarni and coworkers noted that, interestingly, 13 pairs of ribs were present in three - fourths of patients with long - gap ea, while none of those with short - gap ea had such a skeletal anomaly.5 later study by bosenberg and hadley failed to confirm the indicated association between the long - gap ea and 13 ribs in neonates presenting with ea / tef.10 on the other hand, gupta investigated the size of gap between the pouches in patients with 13 pairs of ribs, right - sided aortic arch, and azygos vein anomaly and their corresponding controls. they found that the mean gap did not differ between neonates with 13 pairs of ribs and those with 12 pairs of ribs. however, the mean gap was significantly higher in both right - sided aortic arch and azygos - vein anomaly groups than in their normal controls.11 nevertheless, to the best of our knowledge, no comparison between the short - gap and long - gap ea for the prevalence of the vacterl and non - vacterl - type anomalies has been yet performed. therefore, we aimed to compare ea - associated anomalies, both vacterl and non - vacterl type, between patients with the short - gap and long - gap ea. ethical approval was obtained from the medical ethics committee of the tabriz university of medical sciences. retrospectively, medical records of all newborns managed for ea / tef in tabriz children s hospital and tehran mofid hospital between 2007 and 2010 were reviewed. the pediatric surgery departments of these university - affiliated hospitals are tertiary referral centers for pediatric surgery in northwestern and the capital of iran, respectively.12,13 all infants with ea / tef born in the indicated areas are admitted to either of the two hospitals. both centers keep comprehensive databases on cases with ea / tef, including data on associated anomalies, pregnancy history, and postnatal clinical course. demographic data including gestational age, delivery status (term or preterm delivery), type of delivery (normal vaginal delivery or cesarean section), birth weight, and gender were collected. in addition, associated anomalies including both the vacterl- and non - vacterl - type defects were listed. defects of the vacterl spectrum covered vertebral anomalies (including costal anomalies), anorectal malformations, cardiovascular malformations, tef (distal and/or proximal), renal anomalies, or radial - type limb anomalies.14 diagnosis of the vacterl association was defined as the presence of ea and at least two combined defects of the vacterl spectrum including vertebral, anorectal, cardiovascular, and renal- or radial - type limb anomalies.15 moreover, the non - vacterl - type defect was defined if any of these anomalies was present : hydrocephalus, orofacial defects (cleft lip / palate, supernumerary nostril, and tongue - tie), respiratory system anomalies (choanal atresia, laryngeal anomalies, lung hypoplasia, and diaphragmatic hernia), gastrointestinal anomalies (duodenal atresia, intestinal malrotation, hypertrophic pyloric stenosis, and annular pancreas), genital anomalies (undescended testis, hypospadias, and ambiguous genitalia), and non - vacterl limb defects, eg, lower limb anomalies.14 during the study period (20072010), all the vacterl and non - vacterl components were assessed with the same criteria for all the newborns managed for ea / tef. in this study, ea patients were considered to have long - gap ea when primary end - to - end anastomosis was not feasible due to the length of the gap between the proximal and distal ends of the esophagus ; or anastomosis was performed with tension ; or other surgical techniques including gastric pull up and/or cervical esophagostomy were performed.1619 considering the present investigation as a case - control study, the cases and controls were patients with long - gap and short - gap ea, respectively. demographic data and the vacterl- and non - vacterl - type anomalies were compared between children with long - gap ea and those with short - gap ea. statistical analysis was performed with spss for windows (v 16.0, chicago, il) by using chi - square test, fisher s exact test, and independent - samples t - test wherever appropriate. to express the strength of a significant association, odds ratio (or) between the outcomes of the two groups two hundred and seventy - six children were included in the study : 230 (83.3%) in the short - gap ea group and 46 (16.7%) in the long - gap ea group. patients with long - gap ea were born at earlier gestational age (p = 0.001), were more often delivered by cesarean section (p = 0.01), and had lower birth weight (p = 0.0001). of 276 patients with ea, 197 (71.3%) patients had two or more vacterl - type defects. in contrast, non - vacterl anomalies were detected in 35 (12.6%) patients with ea. although prevalence of the vacterl spectrum anomalies did not differ between the two groups, the non - vacterl anomaly was more common in long - gap ea group (p = 0.02, table 1). among the vacterl - type defects, tef was detected in 30 (65.2%) and 218 (94.7%) patients in long - gap and short - gap ea groups, respectively (table 1, p = 0.0001, fisher s exact test). the study revealed that prevalence of the vacterl spectrum anomalies was comparable between patients with short - gap and long - gap ea. this finding is consistent with that of the study by lopes and botelho disclosing comparable prevalence of associated vacterl type anomalies between short - gap and long - gap ea.2 although al - shanafey and harvey18 and bagolan found similar results, they did not specify whether they studied the vacterl - type anomalies. furthermore, non - vacterl - type anomalies were associated with long - gap ea in the present study. in our series of neonates, an infant with a non - vacterl anomaly was almost three times as likely to have an associated long - gap ea. however, we do not have an explanation for this finding in the present study. in addition, patients with long - gap ea had less tef than those with short - gap ea. this finding, although still in debate, is considered as a definition of long - gap ea by some pediatric surgeons.18 to the best our knowledge, the present study is the first investigation to compare the detailed anomalies, both the vacterl and non - vacterl anomalies, between long - gap and short - gap ea patients. first introduced by quan and smith in 1973, vater association described vertebral defects, anorectal malformation, tef and/or ea, renal anomalies, and radial dysplasia.7 later, cardiac and limb defects were included, hence the vacterl acronym.8 although the underlying etiology of the vacterl association is still unclear, chromosomal anomalies and environmental exposures have been deemed to play etiologic roles.6,14 full or partial vacterl spectrum defects have been reported in 24% to 67% of the neonates with ea / tef.14,2123 almost similar to this range, we found the vacterl association in 71% of the studied population. excluding tef in both short- and long - gap ea groups, the cardiovascular anomalies, followed by the vertebral defects, were most common among the vacterl spectrum anomalies. this trend has been previously reported by keckler and colleagues.6 nonetheless, de jong found an inverse trend ; the vertebral defects were most common, followed by the cardiovascular anomalies. such a discrepancy might be attributed to variations in definition of the cardiac anomalies, ie, intrinsic vs extrinsic heart lesions. the non - vacterl anomalies have been reported in 20% to 70% of ea patients in the previous investigations.14,22,24,25 in the present study, we found the non - vacterl - type anomalies in approximately 13% of the ea patients with or without tef. among the non - vacterl - type anomalies, the respiratory system anomalies and the non - vacterl limb defects were the most prevalent in short - gap and long - gap ea groups, respectively. the former occurred frequently (33.3%) among 15 ea patients studied by yang and coworkers.24 nevertheless, the corresponding figures reported by other authors are much closer to our findings.14,25 an association of ea and the respiratory tract anomalies may imply a defective development of the foregut, a segment from which both the esophagus and the respiratory system develop in the fetus.14 such an association has been previously demonstrated in animal studies.26,27 the present study demonstrated that patients with long - gap ea were born at earlier gestational age. this finding is consistent with that of the studies by al - shanafey and harvey18 and lopes and botelho.2 in contrast, bagolan and colleagues failed to find any difference between the two groups in gestational age.20 similar to the study by lopes and botelho,2 we found that patients with long - gap ea had lower birth weight and were more premature than the short - gap ea group. we applied a pragmatic definition of long - gap ea rather than a numerical definition. moreover, the retrospective nature of this report could affect the validity of the data. only two pediatric surgeons (s aslanabadi and m rouzrokh) have managed our patients. furthermore, associated congenital anomalies were accurately separated for the vacterl and non - vacterl anomalies in a large number of ea patients. in conclusion, the non - vacterl - type anomalies, but not the vacterl spectrum defects, are more frequent in patients with long - gap ea than in those with short - gap ea. furthermore, patients with long - gap ea are born at earlier gestational age, are delivered more by cesarean section, and have lower birth weight. further investigations are needed to determine the predictors of long - gap ea / tef prior to the surgical intervention. | background : predicting the presence of long - gap esophageal atresia (ea) prior to the surgery is of clinical importance. no comparison between short - gap and long - gap ea for the prevalence of vacterl and non - vacterl - type anomalies has yet been performed.objective:the aim of this study was to compare vacterl and non - vacterl - type anomalies between patients with short - gap and long - gap ea.methods:retrospectively, medical records of all newborns managed for ea / tracheoesophageal fistula (tef) in tabriz children s hospital and tehran mofid hospital between 2007 and 2010 were evaluated. demographic data and associated anomalies including both the vacterl and non - vacterl - type defects were listed. the vacterl spectrum defects covered vertebral / costal, anorectal, cardiovascular, tef, and renal- or radial - type limb anomalies. the non - vacterl - type anomalies included hydrocephalus, orofacial defects, respiratory system anomalies, gastrointestinal anomalies, genital anomalies, and non - vacterl limb defects. demographic data, and the vacterl and non - vacterl - type anomalies were compared among children with long - gap ea and those with short - gap ea.results:two hundred and seventy - six children were included in the study : 230 (83.3%) in the short - gap ea group and 46 (16.7%) in the long - gap ea group. although prevalence of the vacterl spectrum anomalies did not differ between the two groups, the non - vacterl anomaly was more common in the long - gap ea group (p = 0.02). among the vacterl - type defects, tef was detected in 30 (65.2%) and 218 (94.7%) patients in long - gap and short - gap ea groups, respectively (p = 0.0001).conclusion : the non - vacterl - type anomalies, but not the vacterl spectrum defects, are more frequent in patients with long - gap ea than those with short - gap ea. |
our case is a 41-year - old man with a 4-year history of schizophrenia, presented with impaired cognition after 2 weeks of hospitalization in meimanat mental hospital in tehran. the patient had no report of fever in his early observation in which he was noted to have tachycardia, muscular rigidity, generalized tremors, mutism and diaphoresis. he had already been under treatment with lithium 900mg/24h, clonazepam 1 mg /hs, one intramuscular injection of 12.5 mg fluphenazine decanoate once every other day 2 weeks before the presentation of nms and three sessions of ect (electroconvulsive therapy). ect was applied due to his prominent positive symptoms of self talking, auditory hallucination and persecutory delusion. initial vital signs showed a pulse rate of 134 beats / min, a blood pressure of 111/79 mmhg and axillary temperature of 37 (c). were dry. physical examination of both lungs revealed no abnormality, but the patient had sinus tachycardia with a regular rhythm. the only positive point in his medical history was an occurrence of deep venues thrombosis of the left leg 2 years earlier. leukocyte count was 12,1000/mm3 with a hemoglobin of 11.8 g% and a hematocrit accounted for 33%. mmol / l, potassium 3.8 mmol / l, blood urea nitrogen level 9 mg / dl, and creatinine stood at 0.8 mg / dl. lumbar puncture evaluation was normal, and computed tumography (ct) of the brain was also performed which showed an old ischemic region in the left parietal lobe being asymptomatic and not clinically important. urine drug test did not show any proof of opiates, amphetamine, cocaine, cannabis tricyclic antidepressants, or barbiturate exposure. the probability of neuroleptic malignant syndrome was considered, so therapy with fluphenazine and ect was immediately discontinued. the renal output vital signs, electrolytes, and fluid balance were monitored. in order to overcome muscle rigidity and antipsychotic - induced dopamine receptor blockade the patient for more supportive care, the patient was admitted to the intensive care unit. over the first 24h of admission, the patient remained mute. on the second day of admission, although the patient 's temperature was normal, his creatinine phosphokinase (cpk) levels increased to 2800u / l. culture evaluation of all blood, urine, cerebrospinal fluid samples were negative for growth. by the second day he responded to navalproate (600mg / day) and lorazepam (3mg / day). a magnetic resonance scan of the brain showed an old ischemic region in the left parietal lobe without any acute pathologic process. the patient was transferred from icu to a regular ward on the 8 day of his admission when cpk level decreased to 1760 the patient remained afebrile until the 8th day of admission when he began to show signs of steadily increasing temperature and diarrhea which was diagnosed as pseudo membranous colitis and was treated with rifampin (450mg / day) and metronidazole (750mg / day). his hospital courses were complicated by deep venous thrombosis (dvt) in the right leg which was detected by the right leg edema and sever pain. therapy with heparin started and followed by warfarin with control of pt after consulting with our cardiologist. the patient was discharged after 15 days of hospitalization with a satisfactory general medical condition and normal mental status. he was then referred to a cardiologist for following up the therapy with wafarin which was recommended to be continued for a long time because of recurrent dvt. ect is one of the considerable strategies for the treatment of nms which has been addressed in many cases in the literature (68). in the review of literature for example, anelopoulos se al reported a 31-year - old caucasian male who developed nms and whose temperature was 37 throughout the episode and was treated with amisulpiride (800mg / day) for 2 years and oxcarbazepine (1200mg / day) for one month (9). moreover, lev and clark stated a case of nms with no initial onset of fever (10). in our patient, one intramuscular dose of 12.5 mg fluphenazine followed by 3 sessions of ect leading to extrapyramidal symptoms and mental status changes. this presentation was similar to observations reported previously by aruna when a patient had been given 25 mg of fluphenazine decanoate injection intramuscularly in addition to his ordinary psychotropic treatment of thioridazine and haloperidol. laboratory analysis indicated rising of creatine kinase, aspartate aminotransferase, alanine aminotransferase levels and leukocytosis (11). in our case, symptoms began just after the 3 session of ect. in a case control study shachdev,. stated that past history of treatment with ect maybe considered as a risk factor for the development of nms (12). on the contrary, we found articles reporting ect as a useful measure to treat nms (58). we detected low grade fever only once upon the occurrence of developing diarrhea during his hospital admission which was considered as a result of dehydration. it is not certain whether receiving 3 sessions of ect have affected the course of nms to be presented without fever in our case. moreover, it was worth considering that in spite of therapy with ect, our patient developed the symptoms of nms. regarding the treatment of nms, the clinicians should focus at supportive therapy and discontinuation of the precipitating drugs. the patient 's intake and output should be seriously taken into consideration throughout the treatment course. rehydration as a supportive action must be initiated to stabilize the patient 's blood pressure. in order to lower the body temperature, cooling blankets, and muscle relaxants such as dantrolene and diazepam are useful in acute situations. providing a satisfactory airway and ventilation are principal, especially when we confront neurologic deterioration. following the discontinuation of the aberrant agent and suitable treatment measures, nms is a life - threatening condition resulting from dopaminergic blockade from antipsychotic medications. in our patient, however, it remains uncertain whether alteration in other neurotransmitter systems besides dopamine caused by ect could be involved in afebrile staging of nms in this patient. we should be aware of this drug - induced condition and the likely increased risk associated with concurrent use of ect and long - acting psychotropic drugs. in patients taking any antipsychotics, we should cautiously investigate any features of nms and should not exclude a diagnosis of nms too early in cases where high body temperature is not primarily evident. thus, it is suggested that attention for any sign or symptom of nms should be well thought - out in patients receiving long acting aps concurrently with ect. | neuroleptic malignant syndrome (nms) is unusual but could be a lethal reaction associated with neuroleptic drugs. it occurs in almost 0.07 - 2.2% of patients under treatment with neuroleptics. there are some medical treatments that may also be helpful for its treatment, including dopamine agonists, muscle relaxants, and electroconvulsive therapy (ect). we present this case to alert the clinicians to the potential for inducing afebrile nms.our case is a 41-year - old man with a history of schizophrenia showing signs and symptoms in accordance with nms, 2 weeks after receiving one dose of 12.5 mg fluphenazine decanoate, abruptly following the 3rdsession of ect. the patient presented with decreased level of consciousness, muscular rigidity, waxy flexibility, mutism, generalized tremor, sever diaphoresis and tachycardia which progressed during the previous 24 h. laboratory data indicated primarily leukocytosis, an increasing level of creatinine phosphokinase and hypokalemia during the next 72h.in patients receiving antipsychotics, any feature of nms should carefully be evaluated whether it is usual or unusual particularly in patients receiving long acting neuroleptics. |
in a series of experiments, two groups of anesthetized pigs were administered cheeses via gastric tube. while one group showed no symptoms after anesthesia, pigs of the other group succumbed in severe anaphylactic shock. the only prior intervention in this group consisted in irreversibly blocking the histamine degrading key enzyme diaminooxidase (dao) before feeding cheese, rich in histamine. as a result, the histamine in cheese could not be metabolized and reached a level comparable to fatal allergic anaphylactic shock. these key experiments for the first time displayed the importance of hindered histamine metabolism and proved the concept of luminal - induced enteral histaminosis. histamine induced symptoms in a growing number of patients, with strong belief in, albeit no evidence for, underlying allergy has generated growing interest. for the classification of these symptoms, the term histamine intolerance (hit) has become popular [2, 3 ]. it is assumed that histamine intolerance results from an imbalance of exogenous histamine intake and/or histamine metabolism due to impaired enzymatic effect for a variety of reasons. the clinical picture of gastrointestinal signs of hit is sometimes puzzled by concomitant lactose intolerance and/or fructose malabsorption. histamine (mw 111) is a small biomolecule, but one of the most extensively studied entities, having at least 23 different physiological functions. histamine, 2-(4-imidazolyl-)ethylamine, is the biogenic amine from histidine that serves as substrate for its rate - limiting enzyme histidine decarboxylase (hdc). histamine is mainly produced in mast cells and basophils, stored in many tissues and released upon a variety of immunological and nonimmunological signals [2, 5 ]. in the body, plp - dependent hdcs are ubiquitous ; they can be found not only in mammalian tissue but also in numerous bacteria. elevated concentration of histamine in some processed foods is explained through contamination from several bacteria and their hdc activity. the metabolic pathways are different in central nervous system (cns) and the periphery, with an extra 3-methylation step in the brain. both types of transformation result in derivatives of imidazole -acetic acid with enhanced water solubility and are excreted in the urine. histamine is a key mediator of allergic and nonallergic diseases and plays its role in allergic rhinitis, urticaria, and anaphylaxis and in bronchial asthma [1, 5 ]. as mentioned, dao converts amines leading to the formation of the final products. at least for putrescine, there is evidence that dao is responsible for conversion also in vivo. in brief, an assay for dao activity is based on the conversion of [1, 4- c]putrescine to 4-amino-[1, 4- c ] butylaldehyde which in alkaline solution spontaneously forms 1-[1, 4- c]pyrroline that can be extracted into an organic solvent for quantization. this assay has been widely used for diagnosis of histamine intolerance and diminished dao levels in plasma imputed to histamine intolerance [6, 7 ]. however, this remained un successful as these results could not be confirmed by others [8, 9 ]. so, only careful history taking of a patient 's symptoms until now confirms the clinical diagnosis of histamine intolerance. skin prick testing is an established technique for diagnosis of type - i allergic reactions such as inhalant allergens, food, or drugs on intact skin [10, 11 ]. for standardization a positive and a negative control 0.9% of physiologic saline solution serves as a negative control, whereas aqueous 1% (10 mg / ml) of histamine hydrochloride solution is used as positive control throughout all tests. likewise a drop of saline solution and histamine solution (pangramin positivkontrolle alk - abello sterreich, / ml, also contains phenol, glycerol, potassium phosphate, potassium chloride, aqua ad inj.) were pipetted on the intact skin and pricked with lancets (m mediware, blutlanzette, steril, premium quality, ref b2 01). asymmetrical wheals were measured as follows : wheal size perpendiculars to each other were measured, divided by 2 and the average wheal diameter used in millimeter (mm). testing was always performed by two investigators (technicians m. e. and m. s.) and results at various time intervals recorded by two investigators (lk and hk) blinded to which group a test person belonged., 17 extra test persons with known histamine intolerance were closely monitored ; the diameter of wheal and erythema was measured every 5 minutes until 60 minutes after skin prick (figure 1). from this, we considered a wheal 3 mm up to 50 minutes as positive. this study comprised 156 probands, (male = 62, female = 94) ; mean age was 29 (control group) and 39 (histamine intolerant group), respectively. all of them were outpatients of the private allergy clinic for different reasons and underwent routine skin prick tests. patients with known inflammatory bowel diseases (crohn 's disease, colitis ulcerosa), irritable bowel syndrome (ibs), and celiac disease had been excluded to participate, as were patients with prior corticosteroid or h1 blocker pretreatment within the last 4 weeks. in all 156 patients on the basis of their, often longstanding symptoms (i.e., headache, palpitations, diarrhea, and pruritus after alcoholic beverages or food, known to be rich in histamine) and physical investigation, we categorized two groups : 81 patients with presumable histamine intolerance and a control group consisting of 75 patients attending the allergy clinic from urticaria, pollen-, or mite - allergy but no history nor any anamnestic signs of histamine intolerance. for analysis of frequency distribution, contingency tables and pearson 's chi - square test were used. data of sensitivity, specificity, positive and negative predictive value and their 95% confidence intervals were calculated (table 1). best discrimination time point between histamine group and control group was calculated from an roc analysis. (1) roc analysis showed that best discrimination between histamine and control group is displayed at 50 minutes. here 50% (n = 78) of all test persons still had a wheal 3 mm ; 17.95% (n = 14) of them were from the control group, but 82.05% (n = 64) from the histamine intolerance group (figure 2). sensitivity of the histamine 50-skin - prick test is 79% (95% confidence intervals : 68.587.3%) and specificity is 81.3% (95% confidence intervals 70.7%89.4%). the negative predictive value of this test is 78.2% (67.486.8%) and the positive predictive value is 82.1% (71.7.589.8%). (2) no differences could be observed between either sexes of patients nor between different ages. (3) wheal diameter peaked at 20 minutes and was slowly diminishing to minute 60 (figure 3). in most publications [810, 1214 ] on histamine intolerance until so far, unvalidated questionnaires for diagnosis have been used, simply as no validated questionnaires are published or available. histamine is a pleiotropic substance, the imbalance of histamine intake and metabolism probably leads to the wide spectrum of symptoms in histamine intolerance. the substrate specificity of amine oxidases is limited, low dao activity might be due to the presence of large amounts of other amineoxidases. therefore data on the expression of dao based solely on activity measurements should be considered cautiously. it was clearly shown in patients with histamine intolerance that plasma dao activity could not be correlated to histamine intolerance [8, 9 ]. an experiment, measuring histamine degrading enzyme acticivity of (healthy) human skin homogenates, displayed that the main histamine degrading enzyme was n - methyl - transferase, not dao. this study, however, was not aimed to evaluate the histamine degrading capacity of skin in hit patients. it is widely assumed, that a double blind oral provocation test with varying amounts of an aqueous histamine solution would serve as gold standard for diagnosis. besides its expense in daily practice, oral provocation with histamine is very difficult to standardize. it has been published that even in patients with overt histamine intolerance oral provocation was positive in only 50% of those tested. very recently a multicenter study on the nonreliability of blinded oral histamine provocation to confirm histamine intolerance has been published. obviously oral histamine provocation test thus can not be considered a gold standard in hit. to date, diagnosis ; therefore, is entirely based on history taking and post hoc affirmation by successful dietary measures. a link between histamine and altered mental state has been published. in kounis - syndrome, among others, depression is said to activate not only a cascade of inflammatory mediators like tnf - alfa, but also triggers mast cells to release histamine : ultimately this leads to symptoms of a coronary syndrome without morphological abnormalities in affected patients [17, 18 ]. the mast cells are the major effector cell in immediate hypersensitivity also the growing importance role of histamine in the amine system in the brain and augmented peripheral histamine effects caused by stress has been elucidated. a lot is known about histamine ; less is known about histamine intolerance in the medical community, and the scientific evidence to date is scarce. only recently the following has been stated : evaluation of more than 200 scientific journal articles and over 30 patient oriented websites dealing with this disease concept diamine oxidase (dao) revealed that a lot more is being alleged and stated than is actually substantiated by scientific evidence. the concept of hit implies that altered histamine metabolism must not only occur in the gastrointestinal tract but in all tissues where signs of hit can be observed. regarding histamine metabolism in the skin, remarkably enough, only few data, for example, from animal studies, are published so far. francis. were among the first to study the role of histamine metabolism in skin in 1977. certainly this awaits further elucidation in future studies, which was beyond the scope of this clinical study, however. almost all of these clinically relevant effects are mediated through h1 receptors, whereas h2 receptors can be mainly found in gastric, cardiac and some gland tissue. it is known that mastocytosis as well as exogenous histamine from food according to its amount can lead to identical symptoms. processed foods, often rich in histamine (such as parmesan cheese, canned fish, and rehashed food), histamine liberating foods, although discussed with controversy [10, 12, 13 ], alcohol [22, 23 ] that blocks dao and may contain histamine such as some red wines and certain drugs, releasing histamine [2427 ] from mast cells such as radiocontrast agents or nsaids, point to the role of histamine as mediator that mimics some features of allergic disease. however, more compelling evidence for the role of histamine comes from observations that specific receptor blockade and dietary restriction leads to long - lasting improvement of symptoms in most of these patients. another intriguing observation can be made during pregnancy of female patients ; during the third trimester the placenta produces many times more dao than it is detectable in nonpregnant women. the improvement of histamine intolerance in many women, although only during their late pregnancy, may support this hypothesis. genetic background might play a certain role ; various single nuclear polymorphisms (snps) for dao have been described [29, 30 ] on chromosome 7. the importance of epigenetics on histamine intolerance is on the dice but has not systematically been investigated until now. the diagnostic uncertainty led us to investigate the usefulness of the histamine skin prick test with readings at 50 minutes, however. we showed, that patients with histamine intolerance and a control group do not remarkably differ in the size of their histamine wheals (figure 3), but remarkably in their time course of the histamine wheals 3 mm read at different time points (p <.0001). this difference in skin prick test allows discriminating for histamine intolerance with sufficient sensitivity and specificity. this test is simple and can be used without any adaption in each office where skin prick testing is performed. combined with a thorough history taking, a sound diagnosis of histamine intolerance can easily be achieved with a histamine 50-skin - prick test. | background. histamine intolerance results from an imbalance between histamine intake and degradation. in healthy persons, dietary histamine can be sufficiently metabolized by amine oxidases, whereas persons with low amine oxidase activity are at risk of histamine toxicity. diamine oxidase (dao) is the key enzyme in degradation. histamine elicits a wide range of effects. histamine intolerance displays symptoms, such as rhinitis, headache, gastrointestinal symptoms, palpitations, urticaria and pruritus. objective. diagnosis of histamine intolerance until now is based on case history ; neither a validated questionnaire nor a routine test is available. it was the aim of this trial to evaluate the usefullness of a prick - test for the diagnosis of histamine intolerance. methods. prick - testing with 1% histamine solution and wheal size - measurement to assess the relation between the wheal in prick - test, read after 20 to 50 minutes, as sign of slowed histamine degradation as well as history and symptoms of histamine intolerance. results. besides a pretest with 17 patients with hit we investigated 156 persons (81 with hit, 75 controls) : 64 out of 81 with histamine intolerance(hit), but only 14 out of 75 persons from the control - group presented with a histamine wheal 3 mm after 50 minutes (p <.0001). conclusion and clinical relevance. histamine-50 skin - prickt - test offers a simple tool with relevance. |
primary central nervous system lymphoma (pcnsl) is an uncommon brain tumor accounting for 2%-5% of all primary brain tumors. between 1970 and 1990, the age - adjusted incidence of pcnsl has increased substantially over the past 30 years. these increases can not be completely explained by changes in medical practice, or by changes in nosology and are independent of overall trends in the incidence of brain tumors and non - hodgkin lymphoma (nhl). pcnsl comprises 2.0% of all brain tumors in korea, with an increase from 1.2% in 1999 to 3.3% in 2009. in 1980, the korean ministry of health and welfare started a nationwide, hospital - based cancer registry (the korea central cancer registry, kccr). the korea national cancer incidence database was constructed by merging the kccr database and all eight population - based regional cancer registry databases, data from an additional medical record review survey, and the cancer mortality database. since 2005, the kccr database has been especially useful for showing trends in cancer registration, including benign and borderline tumors of the central nervous system (cns). one study reported population - based survival data between 1999 and 2004 for primary brain tumors in korea. to predict the future incidence of pcnsl in korea and to facilitate the implementation of efficient health care planning, we have performed a new analysis for nationwide population - based incidence and survival of pcnsl. the kccr had been collecting information on approximately 80%-90% of cancer cases from more than 150 training hospitals across the country. the kccr then expanded cancer registration to cover the entire population under the population - based regional cancer registry program, and additional medical record surveys have been conducted since 2003. the national cancer incidence reports for cancer patients diagnosed since 1999 have been published since 2005. kccr data from 1999 to 2002 and from 2003 to 2007 have been published in cancer incidence in five continents vol. 9 and vol. 10, which reflects the completeness of the incidence data. the basic information available included demographic characteristics of the patients, date of diagnosis, primary site, and histological type of the tumor according to the international classification of diseases for oncology, 3rd edition (icd - o-3). a total of 1,062 cases of primary cns lymphoma newly diagnosed from 1999 to 2009 were analyzed. for survival analysis, we restricted the data to patients diagnosed with histologically confirmed pcnsl from 1999 to 2007. we excluded cases that could not be followed up due to mismatched personal identification numbers and cases that were not first primary sites. as a result, 688 newly diagnosed cases of pcnsl from 1999 to 2007 were included. the survival duration in each case was determined as the time difference (in months) from the date of initial diagnosis to the date of death, date of loss to follow - up, or the closing date for follow - up, whichever came first. crude rates (crs) and age - standardized rates (asrs) were calculated.. annual percent changes (apc) for the incidence rates were calculated using a linear model according to the following formula : (exp(b)1)100, where b is the slope of the regression of the natural logarithm of the asr in a calendar year. kaplan - meier analysis was used to compare overall survival over sex, age group, and year of diagnosis using the log - rank test. we also applied piecewise poisson regression model adjusting sex, age, and year of diagnosis. 9.1 (sas institute inc., cary, nc) and stata ver. 11.2 (statacorp lp, college station, tx). a total of 1,062 primary cns lymphoma patients were registered between 1999 and 2009 ; 614 (57.8%) were males and 448 (42.2%) were females (table 1). the age group between 60 and 69 years old was the largest (n=303, 28.5%). the median age of primary cns lymphoma patients was 58 years (range, 48 to 67 years) (data not shown). the asr was 0.11 per 100,000 in 1999 and 0.25 in 2009 (apc ; 8.8% ; p 2, multifocal or meningeal disease, and uncleaved histology have been associated with shorter survival among cns lymphoma patients. among these factors, many studies have reported a further increase in pcnsl during the eighties and early nineties in immunocompetent patients. in korea, the age group between 60 and 69 years old was the largest (n=303, 28.5%). our study is based on data from a nationwide, population - based cancer registry. although many reports on pcnsl are based on hospital series, survival from population - based registry data has rarely been reported. population - based survival reflects the average prognosis of unselected patients with a variety of natural histories and treatment patterns. the data in the kccr are of high quality, and completeness has been estimated as over 97% in recent years. however, no information on chemotherapy method or radiation extent was available ; therefore, we could not precisely analyze prognostic factors. males had higher incidence than that of females, and the older groups (60s or over) showed the largest increase in incidence rates. our findings may be helpful to clinicians and patients in determining long - term prognoses for pcnsl, and could be used as a master control data set for single - arm clinical trials, especially in asian populations. | purposeprimary central nervous system lymphoma (pcnsl) is an uncommon brain tumor accounting for 2%-5% of all primary brain tumors. few population - based analyses of survival for patients with pcnsl have been conducted, particularly in asian countries.materials and methodsusing the korea national cancer incidence database, 1,062 cases of pcnsl newly diagnosed from 1999 to 2009 were analyzed. the crude rate, age - standardized rate (asr), and annual percent change were calculated. to estimate the observed survival, we restricted the data to between 1999 and 2007 and followed the cases until december 2010. the overall survival was estimated using the kaplan - meier method, and piecewise poisson regression model.resultsthe asr for pcnsl between 1999 and 2009 was 0.17 per 100,000, and the annual percent change from 1999 to 2009 was 8.8% (p < 0.001). the asr of males was higher than that of females, and the older groups (60s or over) showed the largest increase in incidence rates. for all ages, the five - year survival from pcnsl was 29.9% between 1999 and 2007. survival from pcnsl is known to show strong association with age at diagnosis.conclusionthese results are similar to those of previous studies. our findings may be helpful to clinicians and patients in determining long - term prognoses for pcnsl. |
spontaneous intracranial hypotension (sih) syndrome can be observed in patients with a postural headache because of low cerebrospinal fluid (csf) pressure and no previous history of head trauma or dural puncture. sih is caused by spontaneous csf leaks from the spinal meningeal diverticula or the dural rents along nerve sleeves. sih is characterized by spontaneous postural headache with nausea, neck stiffness, vomiting, tinnitus, and vertigo in patients with low csf pressure. brain magnetic resonance imaging (mri) has been used as the diagnostic study of choice for sih because of its ability to identify characteristic abnormalities such as subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain. when sih is suspected on a brain mri, radioisotope (ri) cisternography, and computed tomographic myelography can be used to identify the site of a csf leakage. indirect findings of ri cisternography, such as early visualization of bladder activity, may also be useful in the diagnosis and post - treatment follow - up of csf leakage. although many cases of sih resolve spontaneously with conservative treatment including bed rest, hydration, caffeine, and analgesics, others require the injection of autologous blood into the epidural space with csf leakage. various studies have demonstrated that an autologous epidural blood patch (ebp) is a very effective treatment modality for refractory cases of sih. although targeted autologous ebp seems to be effective, some patients require a repeat autologous ebp because of inadequate control of their postural headache. in our present study, we investigated whether autologous ebp responses correlate with surrogate markers of quantitative findings such as the early visualization of bladder activity in ri cisternography and subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain on mri. we aimed to identify factors affecting the therapeutic outcomes of autologous ebp in sih patients in order to help predict the response to autologous ebp. this retrospective study was approved by the institutional review board of asan medical center (approval number : 20150886), and the necessity for obtaining informed consent was waived as we were only reviewing recorded data. all cases of autologous ebp that were performed with the fluoroscopy - guided technique for sih from january 2006 to december 2014 were reviewed. patients who of the following criteria were included : (1) hospitalized by the neurology department because of symptomatic sih, (2) received autologous ebp under fluoroscopic guidance, (3) both ri cisternography and brain mri results were available, and (4) discharged with significant symptom improvement. the exclusion criteria were : (1) incomplete medical records such as an absence of preprocedural and postprocedural pain scores, and (2) absence of formal reports of ri cisternography and brain mri. among the 202 patients who underwent autologous ebp at our hospital, only 104 met the inclusion and exclusion criteria. the following data were collected and analyzed through a review of electronic medical records : demographic variables, number of ebps, pain scores (vas ; visual analogue scale), early visualization of bladder activity by ri cisternography, and abnormal mri findings, including subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain. early visualization of bladder activity by ri cisternography was defined by the presence of radioactivity in the urinary bladder 1 to 3 hours after a lumbar intrathecal injection of a radioactive tracer. we evaluated the recorded ri activity in the urinary bladder at 30 minutes and 2 hours after lumbar intrathecal injection of the radioactive tracer for early visualization of bladder activity. patients were diagnosed with sih if they had at least 2 of the following 3 criteria : orthostatic headache, low csf pressure, and diffuse pachymeningeal gadolinium enhancement on brain mri. orthostatic headache was defined as a headache that occurs or worsens less than 15 minutes after assuming the upright position and disappears or improves less than 30 minutes after resuming the recumbent position. low csf pressure was defined as a csf opening pressure of less than 60 mmh2o in the sitting position. if these initial supportive treatments failed after 5 to 7 days, patients were referred to the pain clinic and treated with autologous ebp. when patients had orthostatic headache 4 to 5 days after autologous ebp, we performed repeat autologous ebp. the target level of autologous ebp was determined as the level of most increased paraspinal activity on ri cisternography. if additional autologous ebp was required in patients with multiple leakage sites, it was performed at another level that had not been targeted before. targeted autologous ebps were performed using a 21-gauge tuohy needle via a midline or paramedian approach under fluoroscopy c - arm system (oec 9800, general electric healthcare, little chalfont, united kingdom) guidance with the patient in prone position. the epidural space was identified using the loss of resistance technique, and accurate localization was confirmed by ensuring the spread of the injected contrast medium over the targeted epidural space. thereafter, autologous blood was slowly injected until the patient began to complain of back pain or radicular pain. we divided the study subjects into two groups, one including patients in which autologous ebp was performed once (ebp s), and another comprising cases in which autologous ebp was performed twice or more (ebp m). correlation analysis was performed to identify relationships between the number of autologous ebps and radiologic findings, such as early visualization of bladder activity on ri cisternography, subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain on mri. for variables that correlated with the number of autologous ebps and pre- and post - ebp pain score differences, regression analysis was also conducted to evaluate the causal relationship. we divided the study subjects into two groups, one including patients in which autologous ebp was performed once (ebp s), and another comprising cases in which autologous ebp was performed twice or more (ebp m). correlation analysis was performed to identify relationships between the number of autologous ebps and radiologic findings, such as early visualization of bladder activity on ri cisternography, subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain on mri. for variables that correlated with the number of autologous ebps and pre- and post - ebp pain score differences, regression analysis was also conducted to evaluate the causal relationship. there were 39 men and 65 women subjects with a mean age (interquartile range, ir) of 39.2 years (2466). the mean height (ir) and weight (ir) were 165.4 cm (146183) and 62.0 kg (4393). the mean volume (ir) of injected blood was 14.7 ml (9.525). the mean pain scores (vas) before and after the first ebp were 4.6 and 1.1, respectively. incidences of subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain on mri examination occurred in 11 (10.6%), 61 (58.7%), 40 (38.5%), 14 (13.5%), and 22 (21.2%) patients, respectively. the 104 study patients were divided into two groups, according to the number of autologous ebps performed, that is, only once (ebp s, 37 patients), and twice or more (ebp m, 67 patients). as indicated in table 1, the demographic characteristics were not significantly different between these two groups. early bladder activity on ri cisternography showed a statistically significant correlation with the pain score difference between pre- and post - ebp (p < 0.05 ; spearman rho : 0.240). in addition, patients with early bladder activity on ri cisternography had a tendency to need a higher number of autologous ebps (fisher exact test, p = 0.03) (table 2). by correlation analysis, only sagging of the brain and no other variables showed a statistically significant negative correlation with the number of autologous ebps (p < 0.01 ; spearman rho : 0.259). characteristics of spontaneous intracranial hypotension patients who receive single or multiple autologous epidural blood patch treatments proportions of the study patients with early bladder activity scahltenbrand initially introduced aliquorrhea in 1938 to describe a patient with sih, and also suggested that there were 3 possible causes of sih syndrome : increased csf absorption, reduced csf production, and csf leakage. csf leakage into the spinal epidural space causes several symptoms of sih such as spontaneous orthostatic headache with nausea, neck stiffness, vomiting, tinnitus, and vertigo. orthostatic headache due to sih syndrome usually resolves spontaneously, but autologous ebp should be considered to relieve symptoms in refractory cases. autologous ebp has been recommended as the treatment of choice in patients who have failed initial noninvasive treatments such as hydration and bed rest, a generous caffeine intake, and the use of an abdominal binder. the effect of autologous ebp is 2-fold : (1) an immediate effect related simply to volume replacement by compressing the dura mater ; and (2) a subsequent latent effect related to sealing of the leakage. in sih syndrome, the success rate with a first autologous ebp has been reported to be 30 to 87%. we have experienced cases in which 7 autologous ebps were needed to achieve lasting relief. we had aimed in a previous study to elucidate the relationship between autologous ebp responses and ri cisternographic findings, hypothesizing that the number of autologous ebps would be increased if the number of csf leakage levels on ri cisternography were increased. in our previous study, we found that the response to autologous ebp was related to the severity of symptoms but not to the number and location of csf leakages. one of the limitations of our previous study was that we only dealt with the number of leakage sites without any quantitative analysis of the amount of leakage because there are no proper tools to measure this. we, therefore, decided to use 6 surrogate markers of the quantitative evaluation of leakage based on previous studies. the first marker was derived from the study of morioka who evaluated four indirect findings of csf leakage on ri cisternography, such as the early visualization of bladder activity, no visualization of activity over the brain convexities, rapid disappearance of spinal activity, and abnormal visualization of the root sleeves. these authors demonstrated early visualization of bladder activity in ri cisternography in all patients with csf leakage. as the release of radioactive tracer into the systemic circulation by csf leakage increases, early bladder activity can be considered as a surrogate marker of csf leakage. severe intracranial hypotension is characterized by 5 mri findings described by schievink, which we used as the additional surrogate markers : (1) subdural fluid collections or hygromas, (2) pachymeningeal enhancement, (3) engorgement of venous structures, (4) pituitary hyperemia, and (5) sagging of the brain. we investigated in our current study whether autologous ebp responses correlate with these 6 surrogate markers of the quantitative levels of csf leakage. early bladder activity on ri cisternography showed a significant correlation with the pain score and with the number of autologous ebps in our current patient series. although there was no significant difference between these patients and the cases without early bladder activity on ri cisternography, multiple autologous ebp was often needed for patient with early bladder activity on ri cisternography. therefore, we suggest from our current findings that early bladder activity on ri cisternography is a predictive factor for the autologous ebp response. among the 5 mri surrogate markers we evaluated, only brain sagging showed a significant correlation with autologous ebp responses. although this was not significantly different in the cases without sagging of the brain on mri, the patients with sagging of the brain showed better autologous ebp responses. the better responses to autologous ebp treatments in patients with sagging of the brain were considered dependent on the fact that it is helpful to raises the csf pressure by preventing csf leakage sites. thus, we identified early bladder activity on ri cisternography and sagging of the brain as factors affecting the responsiveness to autologous ebp. these variables may, therefore, give some useful predictive information on the therapeutic effects of autologous ebp. first, we analyzed early visualization of bladder activity by ri cisternography because we could not analyze the actual ri activity. if we could get the raw data and analyze the actual ri activity in ri cisternography, this would give more reliable results. second, we considered the therapeutic effect of autologous ebp to be poor if the number of autologous ebps increased. however, the number of autologous ebps is not equivalent to the therapeutic effects of this treatment. this may introduce an error ; however, the patients were discharged after the symptoms of sih syndrome improved. if a postural headache worsened with ambulation or in a sitting position, autologous ebp was conducted again until the symptoms of sih improved. therefore, we decided to determine the treatment response by using the number of autologous ebps, and this modality of evaluation should have less influence on the results. in conclusion, autologous ebp is an effective treatment method for managing sih, and the response to it may be related to the radiologic findings of early bladder activity on ri cisternography and sagging of the brain on mri. however, the number of autologous ebps necessary to achieve symptomatic relief does not correlate with other mri abnormal findings, such as subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, and pituitary hyperemia. these results are meaningful because they reveal that the therapeutic effect of ebp on sih can be predicted. | abstractspontaneous intracranial hypotension (sih) is characterized by postural headache because of low cerebrospinal fluid (csf) pressure. brain magnetic resonance imaging (mri) and radioisotope (ri) cisternography can be used to identify the site of a csf leakage. although autologous epidural blood patch (ebp) is a very effective treatment modality, some patients require a repeat autologous ebp. we investigated whether autologous ebp responses correlate with surrogate markers of quantitative findings.all cases of autologous ebp for sih from january 2006 to december 2014 were enrolled. the demographic variables, number of ebps, pain scores, ri cisternography (early visualization of bladder activity), and mri findings (subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain) were reviewed.patients with early bladder activity on ri cisternography had a tendency to need a higher number of autologous ebps. only sagging of the brain and no other variables showed a statistically significant negative correlation with the number of autologous ebps.the response to autologous ebp may be related to the radiologic findings of early bladder activity on ri cisternography and sagging of the brain on mri. |
type 2 diabetes mellitus (t2 dm) is a worldwide epidemic, particularly in developed and developing countries. peripheral neuropathy, which unfavorably influences patient quality of life quite, is an early and common complication of t2 dm. although reported prevalence rates have differed across studies due to differences in study populations and diagnostic criteria, peripheral neuropathy is involved in 3050% of patients with t2 dm. hyperglycemia is a primary risk factor associated with diabetic peripheral neuropathy, and other independent predictors include t2 dm duration, smoking, alcohol consumption, hypertension, hypertriglyceridemia, and increased body mass index. cardiovascular diseases are the leading causes of death in patients with diabetes, and t2 dm is considered as a coronary artery disease equivalent. vascular changes due to microvascular disease and subclinical atherosclerosis are associated with the development of t2dm - related complications such as nephropathy, retinopathy, and autonomic neuropathy [57 ]. recent studies have demonstrated the relationship between peripheral neuropathy, which is a frequent complication of t2 dm, and atherosclerotic vascular changes. these studies consistently demonstrated the relationship between functional parameters of arterial stiffness and peripheral neuropathy. however, results regarding the relationship between carotid intima - media thickness (cimt) and peripheral neuropathy are contradictory. the relationship between carotid atherosclerosis and cerebrovascular and coronary artery diseases has been demonstrated in many studies. it has been reported that increased cimt, which is measured by b - mode ultrasonography, is correlated with increased aortic intima - media thickness, which is measured by echocardiography, and is a marker of systemic atherosclerosis. the present study investigated the relationship between peripheral neuropathy and functional parameters of arterial stiffness, which were measured by 24-h blood pressure monitoring, and cimt, which was measured by b - mode ultrasonography, in patients with t2 dm. the study population included 161 patients (81 males, mean age 52.608.26 years) with t2 dm, who were examined using ambulatory blood pressure monitoring, carotid ultrasonography, transthoracic echocardiography, and electromyography between april 2013 and january 2014 at selcuk university. the diagnosis of t2 dm was made based on the criteria of the american diabetes association. individuals with clinically proven coronary heart disease, cerebrovascular disease, peripheral vascular disease, congestive heart failure, valvular heart disease, chronic kidney disease, and neuropathy due to other reasons (e.g., alcoholic neuropathy, carpal tunnel syndrome, and cerebrovascular disease sequel) were excluded from the study. patients were divided into 2 groups : those with (n=69) and without (n=92) peripheral neuropathy. venous blood samples for biochemical analyses and hematologic parameters were drawn after 12-h fasting before the patients received any medication. fasting blood glucose, serum creatinine, total cholesterol, high - density lipoprotein cholesterol (hdl - c), low - density lipoprotein cholesterol (ldl - c), triglyceride, white blood cell (wbc), hemoglobin (hb), and glycated hemoglobin (hba1c) levels were recorded. the study protocol was approved by the local ethics committee, and all patients gave their written informed consent to participate in the study. 24-h noninvasive ambulatory blood pressure monitoring was performed in each subject using a mobile o graph 24h pwa (i.e.m. gmbh stolberg germany), which yields a simultaneous measure of brachial bp, pwv, and augmentation index. the device is supported with an expert software package, hospital management system (hypertension management system client server company, iem, gmbh germany), for analysis of all registered measurements. in addition, the device is able to measure central bp and alx@75 by an integrated pulse - wave analysis device. waveforms were recorded with a regular oscillatory brachial cuff suitable for ambulatory measurement the using austrian research centers (arc) solver method (austrian institute of technology, vienna, austria). the arc solver method is a novel method for the determination of aortic systolic bp and aix based on oscillometric blood pressure measurement with a common cuff. blood pressure was measured every 15 min during the day and evening (from 6:00 to 22:00) and every 30 min at night (from 22:00 to 06:00). presence of at least 50 acceptable measurements was considered as an acceptable 24-h blood pressure monitoring recording for our study. the mean systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse - wave velocity (pwv), and alx@75 were calculated for 24 h. the distribution of pwv with age and bp category is described and reference values for pwv are established. the mean pwv found was 6.84 m / s1.65. all patients underwent transthoracic echocardiographic examination using the vivid e9 system with a 1.54.6 mhz probe (ge - vingmed ultrasound as, horten, norway). left ventricular (lv) dimensions and wall thickness were obtained from the parasternal long axis view with the m - mode cursor positioned just below the mitral leaflet tips, perpendicular to the long axis of the lv. all standard conventional echocardiographic assessments were performed according to the published criteria of the american society of echocardiography. cimt was measured recording ultrasonographic images of both the left and right common carotid arteries with a 4.512 mhz linear array transducer (vivid e9 system ; ge medical systems, horten, norway). the intima - media thickness was measured using automated edge detection software as the distance between the lumen - intima interface and the media - adventitia interface. all examinations were performed by a single experienced examiner, who was blind to the clinical and biochemical data. neuropathic pain was defined as pain in the limbs in the absence of history of trauma or any other external cause. bilateral spontaneous pain, hypoesthesia including decreased sensation to pinprick and temperature (cold tuning fork), or paresthesia of the legs were considered as the symptoms of polyneuropathy. response of the achilles tendon reflex was investigated in the knee - standing position, ie, with reinforcement, with a standard reflex hammer. nerve conduction velocity was measured using a nihonkohden electromyography system (nihonkohden meb-9002k vma ep / emg measuring system 2005, usa). patients with 2 or more of the following 4 components were diagnosed with neuropathy : presence of symptoms, absence of ankle tendon reflexes, abnormal scores of vibration perception, and abnormal nerve conduction velocity. spss 17.0 for windows was used for statistical analyses (spss, chicago, il, usa). continuous variables are presented as median or mean sd ; categorical variables are presented as percentage. differences in the continuous variables between groups were determined by t test or the mann - whitney u test, for variables with or without normal distribution, respectively. to test the normal distribution, the pearson correlation coefficient was computed to determine the association between 2 continuous variables. logistic regression analysis with enter method was performed including independent variables being significantly different between patients with t2 dm having a possible causative role for neuropathy (+). the study population included 161 patients (81 males, mean age 52.608.26 years) with t2 dm, who were examined using ambulatory blood pressure monitoring, carotid ultrasonography, transthoracic echocardiography, and electromyography between april 2013 and january 2014 at selcuk university. the diagnosis of t2 dm was made based on the criteria of the american diabetes association. individuals with clinically proven coronary heart disease, cerebrovascular disease, peripheral vascular disease, congestive heart failure, valvular heart disease, chronic kidney disease, and neuropathy due to other reasons (e.g., alcoholic neuropathy, carpal tunnel syndrome, and cerebrovascular disease sequel) were excluded from the study. patients were divided into 2 groups : those with (n=69) and without (n=92) peripheral neuropathy. venous blood samples for biochemical analyses and hematologic parameters were drawn after 12-h fasting before the patients received any medication. fasting blood glucose, serum creatinine, total cholesterol, high - density lipoprotein cholesterol (hdl - c), low - density lipoprotein cholesterol (ldl - c), triglyceride, white blood cell (wbc), hemoglobin (hb), and glycated hemoglobin (hba1c) levels were recorded. the study protocol was approved by the local ethics committee, and all patients gave their written informed consent to participate in the study. 24-h noninvasive ambulatory blood pressure monitoring was performed in each subject using a mobile o graph 24h pwa (i.e.m. gmbh stolberg germany), which yields a simultaneous measure of brachial bp, pwv, and augmentation index. the device is supported with an expert software package, hospital management system (hypertension management system client server company, iem, gmbh germany), for analysis of all registered measurements. in addition, the device is able to measure central bp and alx@75 by an integrated pulse - wave analysis device. waveforms were recorded with a regular oscillatory brachial cuff suitable for ambulatory measurement the using austrian research centers (arc) solver method (austrian institute of technology, vienna, austria). the arc solver method is a novel method for the determination of aortic systolic bp and aix based on oscillometric blood pressure measurement with a common cuff. blood pressure was measured every 15 min during the day and evening (from 6:00 to 22:00) and every 30 min at night (from 22:00 to 06:00). presence of at least 50 acceptable measurements was considered as an acceptable 24-h blood pressure monitoring recording for our study. the mean systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse - wave velocity (pwv), and alx@75 were calculated for 24 h. the distribution of pwv with age and bp category is described and reference values for pwv are established. all patients underwent transthoracic echocardiographic examination using the vivid e9 system with a 1.54.6 mhz probe (ge - vingmed ultrasound as, horten, norway). left ventricular (lv) dimensions and wall thickness were obtained from the parasternal long axis view with the m - mode cursor positioned just below the mitral leaflet tips, perpendicular to the long axis of the lv. all standard conventional echocardiographic assessments were performed according to the published criteria of the american society of echocardiography. cimt was measured recording ultrasonographic images of both the left and right common carotid arteries with a 4.512 mhz linear array transducer (vivid e9 system ; ge medical systems, horten, norway). the intima - media thickness was measured using automated edge detection software as the distance between the lumen - intima interface and the media - adventitia interface. all examinations were performed by a single experienced examiner, who was blind to the clinical and biochemical data. neuropathic pain was defined as pain in the limbs in the absence of history of trauma or any other external cause. bilateral spontaneous pain, hypoesthesia including decreased sensation to pinprick and temperature (cold tuning fork), or paresthesia of the legs were considered as the symptoms of polyneuropathy. response of the achilles tendon reflex was investigated in the knee - standing position, ie, with reinforcement, with a standard reflex hammer. nerve conduction velocity was measured using a nihonkohden electromyography system (nihonkohden meb-9002k vma ep / emg measuring system 2005, usa). patients with 2 or more of the following 4 components were diagnosed with neuropathy : presence of symptoms, absence of ankle tendon reflexes, abnormal scores of vibration perception, and abnormal nerve conduction velocity. spss 17.0 for windows was used for statistical analyses (spss, chicago, il, usa). continuous variables are presented as median or mean sd ; categorical variables are presented as percentage. differences in the continuous variables between groups were determined by t test or the mann - whitney u test, for variables with or without normal distribution, respectively. to test the normal distribution, the pearson correlation coefficient was computed to determine the association between 2 continuous variables. logistic regression analysis with enter method was performed including independent variables being significantly different between patients with t2 dm having a possible causative role for neuropathy (+). in the present study, data of a total of 161 patients (80 females and 81 males) were evaluated. patients with peripheral neuropathy were older (54.688.35 years vs. 51.047.89 years ; p=0.005) and had t2 dm for longer time (month) (60 months vs. 36 months ; p=0.004). likewise, elevated hba1c value, which indicates poorly controlled t2 dm, was higher in the peripheral neuropathy group (8.551.85 mg / dl vs. 7.301.51 mg / dl ; p<0.001). body mass index, serum lipid concentrations, hematological parameters, and serum thyroid stimulating hormone levels were similar in both groups. gfr was lower in the peripheral neuropathy group, but the difference was not statistically significant (table 1). with regard to the results of 24-h blood pressure monitoring, pwv, which is the parameter of arterial stiffness, was statistically increased in the group with peripheral neuropathy as compared to the group without peripheral neuropathy (7.741.14 m / s vs. 7.151.10 m / s ; p=0.001) (figure 1). pulse pressure, which is another important parameter of arterial stiffness, was higher in the peripheral neuropathy group, but the difference was not statistically significant. other results of 24-h blood pressure monitoring were similar in both groups (table 2). lvm index was significantly increased in the group with peripheral neuropathy (98.6826.28 g / m vs. 89.7119.70 g / m ; p=0.02). other echocardiographic parameters were found to be similar in both groups (table 2). anterior measurement (0.740.15 mm vs. 0.670.13 mm ; p=0.01) and posterior measurement (0.650.10 mm vs. 0.600.10 mm ; p=0.006) were statistically significantly increased in the group with peripheral neuropathy (table 2, figure 1). bivariate correlation analysis revealed a significant correlation between pwv with cimt and lvm index (figures 2 and 3). retrospective stepwise analysis was performed in multivariate analysis to detect the predictors of peripheral neuropathy. parameters that were considered to be associated with peripheral neuropathy (sex, age, pwv, cimt, smoking, hypertension, diabetes duration, and hba1c and lvm index) were evaluated. as the result of analysis, duration of diabetes, hba1c, and lvm index were determined to be the predictors of peripheral neuropathy (table 3). increased pwv, which is a parameter of arterial stiffness, and increased cimt, which is an early sign of systemic atherosclerosis, were significantly higher in the peripheral neuropathy group than in the group without peripheral neuropathy. lvm index was higher in diabetic patients with peripheral neuropathy independently of the prevalence of hypertension and antihypertensive medications administered. as expected, we demonstrated a significant relationship of peripheral neuropathy with the duration of t2 dm and with hba1c values. t2 dm is an endocrine disease that occurs secondary to insulin deficiency and that impairs carbohydrate metabolism as well as lipid and protein metabolism. the chronic course of the disease is associated with an increased risk for complications such as retinopathy, nephropathy, neuropathy, and atherosclerosis. many pathophysiological mechanisms, including decreased na+/k+ atpase activity, increased levels of vasoconstrictors such as thromboxane a2 and endothelin, decreased levels of vasodilators such as prostaglandin i2 and nitric oxide, increased aldose reductase activity, increased production of reactive oxygen species and free radicals, increased protein glycation, altered lipoprotein metabolism, and increased protein kinase c activity are responsible for the development of microvascular and macrovascular complications of diabetes [1618 ]. in the present study, a strong correlation was detected between the development of peripheral neuropathy and increasing age, duration of t2 dm, and hba1c level, which is a glycemic control marker. dyck. conducted a study in 264 diabetic patients and found a strong correlation between exposure to hyperglycemia and peripheral neuropathy. many studies have demonstrated a relationship among age, diabetes duration, and hba1c levels, supporting the results of the present study [13,8,20 ]. however, although previous studies demonstrated a relationship among peripheral neuropathy, hypertension, and nephropathy, we found no relationship between hypertension and peripheral neuropathy ; however, a weak relationship was detected between peripheral neuropathy and decreased egfr, which is a marker of nephropathy. cardiovascular disease is a major complication of t2 dm, and cardiac diseases are the cause of death in 68% of patients with t2 dm. although quite important, atherosclerosis is usually asymptomatic, particularly in patients with t2 dm. in a study performed using myocardial perfusion scintigraphy, therefore, the severity of atherosclerotic changes in any segment of the arterial system can provide information about other atherosclerotic involvements in the arterial system. easy visualization of carotid arteries (and thereby determination of the extensiveness of atherosclerosis in these arteries) may also provide information about the presence and severity of accompanying coronary atherosclerosis. it has been demonstrated that intima - media thickening, an early sign of atherosclerosis in the vascular bed, is associated with cardiovascular risk factors and the extensiveness of symptomatic coronary artery disease. moreover, long - term follow - up of asymptomatic patients revealed that increased cimt is associated with an increased risk of stroke and silent cerebral infarction. showed that cimt increases in diabetic versus non - diabetic subjects. a meta - analysis including 4019 patients with diabetes demonstrated a relationship among impaired glucose tolerance, diabetes, and increased cimt. diabetic peripheral neuropathy is a common microvascular complication with high mortality rates, but little is known about the association between diabetic peripheral neuropathy and atherosclerotic vascular changes. a previous study demonstrated that cimt increases in patients with versus without peripheral neuropathy, which is among the chronic complications of diabetes. however, another study failed to demonstrate such a relationship. in the present study, we demonstrated increased cimt in patients with peripheral neuropathy compared with those without peripheral neuropathy. arterial stiffness is a sensitive marker indicative of decreased arterial elasticity and vascular wall injury. a relationship has been demonstrated between carotid atherosclerosis, which is measured by angiography, and increased pwv, an arterial stiffness parameter. pwv is a non - invasive, relatively cheap, easily applicable, and reliable test for measuring arterial stiffness. studies revealed that arterial stiffness measured by pwv increases in patients with diabetes with peripheral neuropathy compared with those without peripheral neuropathy. consistent with previous studies, the present study measured pwv, indicating that arterial stiffness increased in patients with diabetes with peripheral neuropathy. however, the underlying mechanism linking peripheral neuropathy in diabetic patients to arterial stiffness is not well understood. one possible explanation is that large artery stiffness may cause microvascular damage via high pulse pressure, leading to diminished blood flow to nerve tissues vulnerable to hypoxic damage, and thereby to the development of neuropathy. the incidence and mortality rate of cardiovascular events can decrease with treatment of lv hypertrophy. studies have revealed a relationship among age, hypertension, obesity, and the lvm index and, accordingly, lv hypertrophy. the micro - vascular damage, which causes the elevation of central blood pressure, might have a closer relationship with lv hypertrophy and lvm index. in the present study, although blood pressure, prevalence of hypertension and anti - hypertensive medication usage were similar among the patients, the lvm index was increased in the peripheral neuropathy group. this difference can be explained by the micro - vascular damage of the patients with peripheral neuropathy group. also, a relationship between the lvm index and pwv was demonstrated in this study. it was not possible to establish a cause - and - effect relationship between peripheral neuropathy, cimt, and arterial stiffness. moreover, we did not determine predictors of peripheral neuropathy, since neither the patient number nor study design used were suitable for this. it was not possible to establish a cause - and - effect relationship between peripheral neuropathy, cimt, and arterial stiffness. moreover, we did not determine predictors of peripheral neuropathy, since neither the patient number nor study design used were suitable for this. the study determined a significant relationship of peripheral neuropathy with increased pwv and cimt in patients with t2 dm. the duration of diabetes, increased hba1c, and increased lvm index were predictors of diabetic peripheral neuropathy. | backgroundwe investigated the relationship between peripheral neuropathy and parameters of arterial stiffness and carotid intima media thickness (cimt) in patients with type 2 diabetes mellitus (t2dm).material / methodsthe study included 161 patients (80 females and 81 males), 69 of whom had peripheral neuropathy. all patients underwent 24-h blood pressure monitoring, and arterial stiffness parameters were measured. the cimt was measured using b - mode ultrasonography and patients also underwent transthoracic echocardiographic examination.resultspatients with peripheral neuropathy, compared with those without it, were older (54.688.35 years vs. 51.047.89 years ; p=0.005) and had t2 dm for longer periods (60 vs. 36 months ; p=0.004). glycated hemoglobin (hba1c) values (8.551.85 mg / dl vs. 7.301.51 mg / dl ; p<0.001), pulse wave velocity (pwv) (7.741.14 m / s vs. 7.151.10 m / s ; p=0.001), cimt (anterior 0.740.15 mm vs. 0.670.13 mm ; p=0.01), and left ventricular mass (lvm) index (98.6826.28 g / m2 vs. 89.7119.70 g / m2 ; p=0.02) were all significantly increased in the group with peripheral neuropathy compared to the group without peripheral neuropathy. we determined that duration of diabetes, hba1c, and lvm index were predictors of peripheral neuropathy.conclusionsa significant relationship was found between diabetic neuropathy and increased pwv, a parameter of arterial stiffness, as well as cimt, a marker of systemic atherosclerosis. diabetic peripheral neuropathy may be a determinant of subclinical atherosclerosis in t2 dm. |
extracerebral arteries branch off into pial arterioles that surround the surface of the brain and then penetrate the brain parenchyma at right angles as penetrating or parenchymal arterioles (edvinsson and mackenzie, 2002). parenchymal arterioles in turn give rise to an extensive capillary network, the distribution of which is associated to the metabolic demands of the neuronal microenvironment (edvinsson and mackenzie, 2002). the neurovascular control of the cerebral circulation varies, depending on the location and caliber of the vessels. in general, extracerebral vessels are innervated by peripheral nerves (extrinsic innervation) originating from the superior cervical, sphenopalatine, otic, internal carotid, and trigeminal ganglia (gulbenkian., 2001). intracerebral parenchymal microvessels are primarily regulated by local interneurons and neuronal terminals from a central origin (intrinsic innervation) such as the basal forebrain, raphe, and locus coeruleus (iadecola, 1998 ; gulbenkian., 2001 these arterioles are also regulated by surrounding glial cells and, to some extent, by peripheral nerves that penetrate the brain parenchyma (goadsby and edvinson, 2002). much of the brain infrastructure is needed to provide neurons with the proper delivery of oxygen and glucose, given the limited energy reserves of the brain. to accomplish this, the brain possesses two fundamental mechanisms namely, autoregulation and functional hyperemia (iadecola and nedergaard, 2007) which are tightly controlled by the intrinsic properties of the vascular cells and by signals released from the various cell types that make up the nvu. the activation of these mechanisms warrants constant blood flow and increased oxygen and glucose delivery under conditions of intense neuronal stimulation. at the cellular level, the cells that make up the nvu mainly include vascular cells [endothelial cells (ec), pericytes and vascular smooth muscle cells ], neuronal terminals or varicosities, astrocytes with their corresponding specialized endfeet processes, and microglia. the interaction between these various cell types aid in the establishment of the blood brain barrier and the control of cerebral blood flow. cell - to - cell interactions are futher supported by structural components such as gap junctions (simard., 2003 ; figueroa and duling, 2009) and anchoring proteins (e.g., integrins ; del zoppo, 2010) as well as by the functional activation of various ion channels [e.g., aquaporin 4, k channels, transient receptor potential (trp) channels (brayden., 2008) ] strategically expressed on membranes of the cells of the nvu. these associations are crucial for the structural integrity and functional capacity of the nvu. on a larger scale, for example, specialized gap junctions link astrocytes to one another forming a syncytium (theis., 2005). these glial networks efficiently modulate the activity of neuronal populations (giaume., 2010). in addition, the intimate anatomical association of astrocytic processes with synapses and blood vessels places them in an ideal position to integrate neuronal activity with changes in vascular dynamics. (2008) providing evidence that the glia limitans plays an important role in upstream cerebral vasodilation following neuronal stimulation or hypercapnia - induced pial arteriolar dilation (xu., 2004). while astrocytic endfeet processes occupy a significant portion of the abluminal surface of the vessel wall (kacem., 1998 ; simard., 2003), other innervations such as neuronal terminals and varicosities of various origins have also been described, suggesting direct neurovascular regulation. for example, basal forebrain nitric oxide synthase (nos) neurons (tong and hamel, 2000) and dopaminergic neurons have been shown to make close contacts with cerebral microvessels or with astrocytic endfeet (krimer., 1998). (2004) provided structural and functional evidence for the involvement of gabaergic interneurons containing vasoactive mediators such as no. clearly, specialized contact areas such as the space between neuronal terminals or varicosities and astrocytic endfeet with the vascular wall provide structural evidence for the intricacy of the signaling mechanisms underlying nvc in the brain and the dynamic interactions between neuronal, glial and vascular networks. the in vitro brain slice preparation constitutes an ideal model to study cell - to - cell communication since it possesses all of the constituents of the nvu with the addition of local circuits that allow for the precise stimulation of discrete neuronal and/or astrocytic targets while simultaneously monitoring the activity of the vascular cells. in addition to the above structural observations, strong functional evidence supports an important role for neurons in nvc. the release of neurotransmitters (e.g., glutamate and gaba) has been associated with vasomotor responses both in vivo and in vitro (drake and iadecola, 2007). a direct vasomotor effect from neuronally derived signals has been suggested for dopaminergic, serotonergic, norepinephrine and acetylcholine fibers as well as for neuronally derived neuropeptides such as substance p, neurotensin, vasoactive intestinal peptide (vip), somatostatin and neuropeptide y (for review see, hamel, 2006 ; drake and iadecola, 2007). (1995) showed evidence that no contributes to basal vascular tone and that cgrp dilated parenchymal arterioles. interestingly, the magnitude of the vascular response to cgrp was dependent on the degree of arteriolar tone, suggesting an interplay between these signals (fergus., 1995). in slices perfused with a thromboxane a2 agonist (u46619) to induce arteriolar tone, nmda produced vasodilation via an no - dependent mechanism (lovick. vasodilation of cortical arterioles has also been associated with the activation of cholinergic fibers (vaucher and hamel, 1995 ; vaucher., 1997) and no - containing neurons (tong and hamel, 2000). tong and hamel (2000) suggested that the anatomical interaction between the cholinergic and nitrergic systems may serve to potentiate vascular responses via acetylcholine 's influence on no signaling (tong and hamel, 2000). (2004) showed that stimulation of single interneurons expressing vip or nos mediated vasodilation, whereas stimulation of interneurons expressing somatostatin and neuropeptide y produced microvessel constriction. microinjection of dopamine produced constriction of 50% of microvessels (krimer., 1998). as has been the case with neurons, evidence exists that astrocyte - derived signals can also trigger vascular responses and play a pivotal role in the signaling mechanisms involved in nvc (takano. astrocytic activation results in the release of vasoactive agents (carmignoto and gomez - gonzalo, 2009 ; koehler., 2009) capable of inducing localized vasodilation (in vitro an in vivo) and/or vasoconstriction (in vitro only) of parenchymal arterioles. astrocytes respond to an increase in synaptic activity with a rise in intracellular ca (cornell - bell., 1990 ; if the strength of synaptic activity is high, it triggers the propagation of a ca wave that travels to nearby microvessels (zonta., 2003b ; fellin and carmignoto, 2004 ; filosa., 2004). furthermore, astrocytes synthesize and release a number of vasoactive substances such as no (wiencken and casagrande, 1999 ; li., 2003), prostacyclins, prostaglandins, epoxyeicosatrienoic acids (eets), glutamate, adenosine, and atp (harder., 2002 ; li, 2003a, b ; anderson., 2004 ; takano., 2006) making them key candidates in nvc. despite significant progress in our understanding of the signaling events involved in nvc and the contributing role of neurons and astrocytes, recent findings have raised new challenges to the field. for example, while the physiological significance of neuronal and astrocyte - induced vasodilatory responses is clear, it is still not apparent what is the physiological significance for stimulus - induced vasoconstriction at the site of neuronal activation (girouard. ; cauli., 2004 ; mulligan and macvicar, 2004 ; metea and newman, 2006 ; rancillac., more importantly, based on functional and structural observations, it has been proposed that vessel - to - glia or vessel - to - neuron signaling may play an important role in brain information processing (moore and cao, 2008), highlighting the importance of vascular - derived signals and raising the question as to whether information within the nvu flows in a bi - directional manner (kozlov., 2006 ; paton., 2007 ; moore and cao, 2008 ; del zoppo, 2010). under physiological conditions and in response to intraluminal pressure, arterioles display myogenic tone (i.e., constrictions independent of innervation). the mechanisms for this tone - dependent constriction have been extensively studied, and are underlined by an interplay between ion channels that increase intracellular ca (e.g., vdcc, trpv4) (knot and nelson, 1998 ; inoue., 2004 ; zhang., 2009 ; ma., 2010) as well as opening of k channels (e.g., bk, ik and sk) that oppose ca - dependent mechanisms leading to hyperpolarization and vasodilation (nelson., 1995 ; wrzosek, 2009). the expression of these channels varies depending upon the cell type (e.g., ec or vsmc) and the location and caliber of the vessel. in a recent review dunn and nelson (2010) in addition to the intrinsic properties of the vsmc, vascular tone is regulated by ec signaling. ec release vasodilating (e.g., no, endothelium - derived hyperpolarizing factor, prostanoids) and vasoconstricting (e.g., endothelin, txa2, prostaglandin) substances (andresen., 2006 ; moreover, ec express an array of ion channels that, when activated, can directly or indirectly alter the membrane potential (vm) of the vsmc, establishing ec - to - vsmc coupling. in excised parenchymal arterioles, cipolla. (2009) showed the contribution of sk and ik channel activity (expressed in ec) on vascular tone. direct interactions between ecs and astrocytes have also been proposed, providing structural and functional evidence for bi - directional communication between these cells (leybaert.,, peppiat demonstrated pericyte constriction following electrical stimulation, purinergic activation, or gaba blockers, likely exemplifying an additional form of bi - directional communication between pericytes and ec and a form by which pericytes may control blood flow perfusion to capillary beds (peppiatt and attwell, 2004). based on the intrinsic mechanisms controlling vascular tone and the intricate structural arrangement of the nvu, one can say that vsmcs are sandwitched from the luminal and abluminal side by functionally dynamic cells (ecs and astrocytes)., 2008 ; feletou and vanhoutte, 2009), that are known to play a major role in vascular tone have been observed in astrocytes. figure 1 illustrates the various vasoactive signaling pathways described in the endothelium and also observed in astrocytes. functional overlapping mechanism from the luminal (endothelium) and abluminal side of a parenchymal arteriole. in addition to direct neuronal - vessel interactions vascular smooth muscle cells (vsmc) are tonically influenced by agonists and/or mechanically activated pathways from the endothelium and from signals released by astrocytic processes also in direct contact with the vessels. the presence of polarized and discrete ion channel types in the layer formed by endothelial cells and astrocytes, provides functional further support for bi - directional communication between these cells and vsmc, as well as, for an electrotonic arrangement capable of modulating vascular tone and conduction of signals over long distances along the microvessel. vdcc (voltage - dependent ca channels), trpv4 (transient receptor potential vanilloid), bk (ca - activated voltage - dependent k channel), ik (intermediate conductance ca activated k channel), sk (small conductance ca activated k channel), and kir (inwardly rectifying k channel). as is the case in ec - to - vsmc signaling, the close association between astrocytes to vsmcs may relate to the need to maintain or control vascular tone within optimal levels. to achieve this, astrocytes would need to constantly monitor hemodynamic changes and locally release vasoactive factors that adjust vascular diameter and maintain cbf constant. if astrocytes contribute to the tonic regulation of vascular tone, it may explain why functional hyperemia studies do not call for an important role for astrocytes and may provide a new meaning to astrocyte - induced vasoconstriction. while the role for astrocytes in functional hyperemia may be indeed relevant, their vasodilatory actions (takano., 2006) may be modulatory depending on the neuronal pathways activated or degree of stimulation. in other words, it is possible that the vasoconstrictive role of astrocytes is primarily linked to their contribution to the re - establishment of vasomotor tone following neuronal stimulation or tone adjustments following hemodynamic - induced vascular responses to sudden blood pressure changes as occurs during autoregulation (harder., 2002). (2008) suggested that the polarity of the vascular response to glia - derived vasoactive signals is coupled to oxygen concentration levels, which in turn determine the metabolic state of the tissue. increased lactate inhibits the activity of prostaglandin e2 (pge2) transporters, raising extracellular pge2 levels and thus favoring vasodilatory responses when po2 levels are low (chan., 2002). on the other hand, the authors suggested that vasoconstriction responses occur under hyperoxic conditions, where lactate levels are low and extracellular pge2 availability is decreased (gordon., 2008). (2010) recently challenged these findings by showing that in anesthetized rats, cbf responses to electrical forepaw stimulation or cortical spreading depression under conditions of hyperbaric oxygenation (absence of hemoglobin deoxygenation) were independent of o2 levels. likewise, a study by metea and newman (2006) in the retina showed that astrocytes induce both vasodilation and vasoconstriction, but in their case the polarity of the response was dependent on no availability. while no inhibition leads to vasodilation, no availability favored vasoconstriction (metea and newman, 2006). the later observation was attributed to no interactions with arachidonic acid (aa) metabolites favoring vasoconstriction through the potential no inhibiting effects on cytochrome p450 (udosen., 2003) and decreased downstream formation of the vasodilating metabolites, eets (metea and newman, 2006). in support of these findings, rancillac. (2006) showed that glutamate - induced no released from cerebellar slices resulted in vasoconstriction of microvessels preconstricted with u46619. given the strong evidence for no inhibition of 20-hete formation (alonso - galicia., 1997) and the ability of the aa metabolites, eets and 20-hetes, to modulate the activity of large conductance ca - activated k (bk) channels in vascular cells (feletou, 2009) and astrocytes (gebremedhin., 2003, 2005) one possibility for no - mediated constriction could be tonic eet - dependent bk activation in astrocytic endfeet, resulting in k accumulation and vsmc depolarization. a role for k channel - induced vasodilation and vasoconstriction was recently discussed by girouard. in a previous study, we showed that bk channel activation in astrocytic endfeet contributes to vasodilatory responses in parenchymal arterioles (filosa., 2006). moreover, our group also showed that the magnitude of the k - induced vasodilatory response was correlated to the degree of tone of the arteriole, highlighting how changes to the intrinsic properties of the vsmcs alters their sensitivity to a given signal (blanco., 2008). (2010) recently showed that at the same level of tone, opposite type vascular responses could be evoked by varying k levels at the gliovascular space. the magnitude of the ca change in the astrocyte determined the amount of k efflux from the endfeet. it is suggested that low or modest changes in k levels activate inwardly rectifying (kir) channels in vsmcs (filosa., 2006) leading to vasodilation whereas high k levels at the gliovascular space cause vsmc depolarization and thus vasoconstriction. these studies suggest that in order to accurately interpret stimulus - induced vascular responses, the cells at the nvu must be close to physiological conditions including the steady - state of the ec and vsmcs, the resting vm of the vsmcs, and the ca dynamic in all of the cells. undoubtedly, no signaling plays a central role in nvc studies ; however, the precise cellular sources and downstream targets for no are largely unknown. while no is believed to be the predominant signal in the cerebellum (yang., 1999 ;, findings from the cortex would suggest no action in nvc are modulatory (lindauer., 1999). in brain slices, nos inhibition with l - nna induced constriction of parenchymal arteriole, suggesting a tonic vasodilatory influence (fergus., 1996), and neuronal stimulation - induced vasodilatory responses are in part mediated by no derived from a neuronal origin (lovick., 1999 ; brown., 2000 (2007) showed that inhibiton of nnos significantly decreased vasodilatory responses to stimulation while de labra. (2009) recently suggested that stimulation - induced hemodynamic changes were associated with both enos and nnos activity, depending on the degree of stimulation. in addition, de labra suggested that no from a vascular or glial source had a more prominent role in low frequency - induced vascular responses, while no from a neuronal source played a more prominent role during intense stimulation. data from these studies would suggest a possible mechanism by which the degree of stimulation may recruit the participation of different elements of the nvu, or networks, in orchestrating vascular responses. altogether, the ability of no to interfere with aa signaling pathways in astrocytes (metea and newman, 2006), vascular tone (feletou., 2008), neuronal activity (ferraro and sardo, 2004) and signaling events that affect many of the constituents of the nvu (i.e., k channel activity) brings into question whether interference with no signaling alters the basal activity of the cells making up the nvu, disrupting, in turn, bi - directional steady - state communication pathways that optimize vascular responses to neuronally derived signals. evidence supporting a role for astrocyte - derived no in controlling vascular tone was provided by chisari. (2004) ; co - cultures of basilar artery with activated lps glia showed changes in vascular tone induced by no. moreover, because no alters ca activity in astrocytes (bal - price., 2002), it is possible that endothelial - derived no contributes to basal astrocytic activity. future studies addressing the dynamic interactions between vascular cells and astrocytes in a bi - directional manner will help elucidate how interfering with these pathways may result in variable vascular responses following neuronal excitability. albeit these important observations and given confounding differences in the data obtained by various groups, a clearer understanding of nvc mechanisms may be possible if an improved and better standardized brain slice preparation is developed. ideally, this preparation should include important hemodynamic variables such as intraluminal pressure and/or flow and take into consideration the levels of cellular activity at rest. while numerous efforts have been made to maintain neuronal and glial viability in brain slices (collingridge, 1995 ; brahma., 2000 ; hjos and mody, 2009), little consideration has been made to ensure penetrating cerebral arterioles are maintained near physiological conditions when using this preparation. to this end, experts in the microcirculation field have provided extensive reports, albeit on excised arterioles, on the criteria needed to obtain proper vascular responses, and how changes to these variables could account for significant alterations in vascular reactivity and function (ngai and winn, 1995). however, only one study (lovick., 2005) attempted to mimic these conditions in the brain slice preparation. in an attempt to mimic physiological conditions, the solutions used to perfuse brain slices have been adjusted to include much of the constituents of the cerebrospinal fluid (csf) (reid., 1988 ; hjos and mody, 2009). while these solutions have proven to be successful in achieving reliable electrophysiological and imaging recordings from both neurons and astrocytes, a closer look at some of the major constituents of the artificial csf (acsf) for example, glucose concentrations used by most researchers (1025 mm) far exceed that of the actual csf (2.5 mm) (silver and erecinska, 1994). in addition, the use of 95% o2 has also been shown to result in different neuronal excitability levels and in the production of superoxide () and cell death (d'agostino., 2007 ; hjos and mody, 2009). moreover, (2008), tissue po2 levels may also have a crucial impact on the physiological response of vascular cells. another important player affected by o2 levels is no. given that no production is dependent on o2 availability (kojima., 2001) and its presence influences cell function and nvc outcomes, caution should be taken when interpreting results where these variables are not carefully controlled or monitored. so what would be the ideal acsf solution when performing nvc experiments in brain slices ? while more data is needed to better address this question, perfusing slices with a 20% o2 solution might be closer to physiological conditions and is unlikely to induce cell death (d'agostino., 2007). in a recent study, ledo. (2010) simultaneously measured no and o2 levels 200 m deep into the slice using an acsf solution bubbled with 95% o25% co2 ; under these conditions o2 levels were around 57.3 38.2 m. to our knowledge the outcome of 20% o2 levels on no availability at different depths of the brain slice has not been explored and would need further consideration, given the steep o2 gradient from the surface of the slice to deeper layers (200 m) (ledo., 2005). in addition, an even closer physiological approach would be to perfuse parenchymal arterioles with a solution that mimics blood constituents, establishing suitable po2 gradients at the nvu before and during intense neuronal activation protocols are used. a similar approach has been extensively used in the renal physiology field where a renal arteriole is perfused with normal blood and hemodynamic variables are measured under different conditions (casellas and navar, 1984 ; casellas and moore, 2003). an approach of this nature would allow the exploration of further questions such as the effect vascular - derived signals have on resting astrocytic and neuronal function. altogether, these observations call for a more optimized in vitro model to dissect the underlying signaling mechanisms of nvc. while we strongly believe brain slices to be an ideal in vitro model, we suggest the inclusion of the following criteria : (1) optimal neuronal and astrocytic viability / activity and (2) optimal physiological conditions for the arteriole under investigation. as previously shown, brain slices should be kept under conditions that prevent cell swelling to maintain the viability of the neurons and astrocytes. in addition, the penetrating cerebral arterioles need to be exposed to an intraluminal solution that maximizes the viability of the vascular cells. the presence of myogenic tone should be used as an indication that vascular cells have achieved optimal resting activity, the state at which vascular responses would be comparable to those under in vivo conditions. using an in vitro preparation in which all the components of the nvu are brought to a closer physiological condition will provide more reliable interpretations of the dynamic interactions between vascular cells, astrocytes, and neurons in the brain. here we highlight previously reported experimental paradigms from which successful arteriolar myogenic tone and flow can be achieved in penetrating cerebral arterioles removed from the brain or from brain slices (dacey and duling, 1982 ; ngai and winn, 1995 ; cipolla., 2004 ;, penetrating arterioles can be cannulated at one end and pressurized under no - flow conditions (ngai and winn, 1995). following a successful cannulation, the arteriole is slowly pressurized in a stepwise manner until an intraluminal pressure between 20 and 40 mmhg is achieved and the vessel shows spontaneous tone (dacey and duling, 1982, 1984 ; ngai and winn, 1995). this latter step is typically conducted at 35c to further stimulate tone (ngai and winn, 1995). arterioles are allowed to equilibrate to their steady - state pressure before experimental protocols are executed. to maintain intraluminal pressure constant, the distal end of the arteriole is clamped and pressure is continuously monitored from a pressure transducer connected to a computer. in addition to intraluminal pressure, using the same cannula approach, flow can be introduced into parenchymal arterioles and its effects incorporated into experimental questions (lovick., 2005). as previously performed in renal tubules, fluorescence recovery after photobleaching can be used to measure mean axial velocity of the intraluminal perfusate (flamion., 1991) within the penetrating arteriole and thus provide a measurement of flow rate, a parameter not well investigated, but likely key in nvc - associated responses. for example, flow rate (shear stress) can induce no production from the endothelium, changing the steady - state diameter (tone) of the arteriole and possibly vascular reactivity to vasoactive signals released by astrocytes and/or neurons (ngai and winn, 1995). thus, one important question still to be determined is whether, under different hemodynamic conditions, cerebral arterioles would behave similarly to glial / neuronal - derived signals. an additional question, and suggested by the recently proposed hemo - neuronal hypothesis (moore and cao, 2008), is whether different hemodynamic conditions can alter neuronal excitability in the brain. significant advances to this already reliable in vitro model will help expand our understanding of the cellular events underlying nvc in the brain. contrary to the disadvantages mentioned above, the brain slice preparation offers a number of advantages including : the presence of all of the cellular constituents comprising the nvu, the use of low - dose pharmacological agents to better define the cellular mechanisms underlying nvc, the unlimited access to brain regions of interest, and the simultaneous monitoring of the activity of multiple cell types. moreover, the brain slice preparation allows for the study of cell - cell communication such as mechanisms underlying intracellular conduction throughout the astrocytic network and/or vascular networks and detailed mechanisms such as the spread of electrical conduction between cells with major emphasis on ecs. in summary, further consideration and improvements are indeed needed to better address the signaling mechanisms underlying nvc in the brain. while in vivo approaches provide the ultimate clues to the understanding of how the brain communicates with the surrounding microcirculation, studies in brain slices have provided seminal observations on the cellular events underlying functional hyperemia in the brain. an optimized in vitro model will help address future unexplored questions such as the importance of studying nvc in different brain regions (inaccessible with current in vivo techniques) where the microenvironment of the nvc is drastically different. the above observations also suggest that nvc mechanisms are driven by a multiplicity of signals and conditions. however, among future questions to address is the physiological function of neuronal - induced vs. astrocyte - induced vascular responses. based on in vivo findings, a current suggestion is that increases in cbf in response to neuronal stimulation is mainly driven by neuronal networks (rossier, 2009) with vasoconstriction distant to the site of activation (devor., 2007). if this were the case, one possibility is that astrocytes contribute to basal cbf regulation or in the spatial spread of stimulus - dependent cbf activation to upstream vessels (xu., 2008). clearly, astrocytes possess vasoconstrictive and vasodilatory signals ; however, in vivo studies have only associated their activation to vasodilation (takano., 2006). we suggest that the vasoconstrictive action of these cells may be involved in the local maintenance of vascular tone, which plays an important role in determining the degree and efficiency of vascular responses to neuronally derived signals. moreover, we predict that under basal conditions, vsmcs are under tonic influences by ec and astrocyte - derived signals, which are overwritten by neuronal signals following increases in neuronal activity. accordingly, astrocytes may participate in autoregulatory mechanisms and also help re - establish vascular tone following hyperemic responses (harder. the author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. | neurovascular research has made significant strides toward understanding how the brain neurovascular unit accomplishes rapid and spatial increases in blood flow following neuronal activation. among the experimental models used, the in vitro brain slice preparation provides unique information revealing the potential signals and cellular mechanisms involved in functional hyperemia. the most crucial limitation of this model, however, is the lack of intraluminal pressure and flow in the vessels being studied. moreover, differences in basal vascular tone have led to varied interpretations regarding the polarity of vascular responses following neuron - to - glial stimulation. given the complexity of astrocyte - induced neurovascular responses, we propose the use of a modified in vitro brain slice preparation, where intraluminal arteriolar pressure and flow are retained. throughout this review, we discuss the advantages and disadvantages to be considered when using brain slices for neurovascular studies. potential ways to overcome the current limitations are proposed. |
in both developed and developing countries, low birth weight is an important factor that effects neonatal mortality, and infant and childhood morbidity[1, 2 ]. considerable attention has been focused on the causal determinants of birth weight, and especially of low birth weight (lbw), defined by world health organization (who) as birth weight less than 2500 g. below this value, lbw infants carry a forty - fold increased risk of death than normal birth weight babies. who estimate that more than 20 million infants worldwide are born with low birth weight, and this constitutes 15.5 per cent of all births. more than 95 per cent of lbw infants are born in less developed countries[4, 5, 6 ]. beside its critical role in aggravating perinatal mortality rates, lbw is a reliable indicator in monitoring and evaluating the success of maternal and child health programs. additionally, it is believed that, lbw may be a predisposing condition for adult diabetes, hypertension and coronary heart disease. each year approximately 10 million children under the age of five die, globally, yet most are overlooked by national health - information systems. almost 40% of all deaths in these children occur in the first month of their life, and 30% in the first week. until recently, most attempts to improve information about child deaths focused mainly on the postnatal period. stillbirths have not been as well studied despite the fact that more than 3 million stillbirths occur annually (who report this number to be 3.3 million in 2005)[3, 4 ]. the estimated stillbirth rate for the developed countries is 5.3 per 1000 deliveries while in developing countries it is 25.5 per 1000[3, 9 ]. in the study of erdem, evaluating perinatal mortality in turkey, the relation between lbw and stillbirths usually goes unrecognized. fetal growth restriction and lbw are both important factors for stillbirth. although lbw seems to be a universal problem across less developed countries, striking regional variations exist. determinants of lbw may vary across different settings and there is need for analysis within different environments. this paper attempts to overview local lbw and stillbirth trends in dr ltfi krdar kartal training and research hospital, also considering, the relationship of sex, maternal age and mode of delivery to these variables. this is a retrospective study on local lbw and stillbirth delivery trends over five years. ltfi krdar kartal training and research hospital, which is one of the largest tertiary care state hospitals, located on the suburbs at the asian side of istanbul, with a neonatal intensive care unit (nicu) of 25 beds. it is a teaching hospital frequented by the local population, which not only live in its immediate surroundings that took a lot of migration over the last few decades from all over turkey, but also share an under - privileged socio - economic background. the information regarding the deliveries between january 1, 2004-december 31, 2008 at the hospital were all collected from delivery registry records of the obstetrics departments. birth weight, sex, maternal age and the baby 's vital status at delivery as well as the mode of delivery were recorded and evaluated. this study was approved by local institutional ethics committee. who define viability as a birth weight of at least 500 g, at the gestational age of at least 20 weeks. eligibility criteria on the inclusion of subjects of this study were based on this definition. a stillbirth was defined as : intrauterine death of a fetus weighing at least 500 g after 20 completed weeks of gestation occurring before the complete expulsion or extraction from its mother[11, 12 ]. birth weight was defined as the first measurement of body weight, usually in the first hour of life measured to the nearest gram. a low birth weight (lbw) infant was defined as an infant weighing less than 2500 g at birth irrespective of gestational age. infants whose birth weight was less than 1500 g and 1000 g were evaluated as very lbw (vlbw) and extremely lbw (elbw) respectively[1, 4, 8 ]. the frequency of elbw and vlbw births was determined in lbw newborns. lbw babies were further grouped into 35 years). within each group, lbw and the 2500 g babies were compared in terms of the relationship between birth weight and maternal age. statistical calculations were performed with ncss 2007 program for windows. beside standard descriptive statistical calculations (frequencies, mean and standard deviation), one way anova was used in the comparison of groups, and chi square test was performed during the evaluation of qualitative data. for the comparison of maternal age and the weight of the newborns, one way anova and unpaired t test were performed. in a period of five years, among 19,533 total births, the number of live - births was found to be 19,083. a total of 450 deliveries (23.04 per 1000 births) were stillbirths (table 1). as shown in table 1, the rate of lbw deliveries increased between 2004 (6.93%) and 2008 (14.13%). this increase in the yearly distribution of lbw deliveries during the study period was found to be statistically significant (p 1500 g birth weight groups were 99,87 (ci95%=74.62133.7), 56.59 (ci95%= 41.577.1) and 13.87 (ci95%=10.7217.97) respectively. sex : within a five - year study period, of the total 19,533 deliveries, 9288 (47.55%) newborns were females and 10,245 (52.45%) males. the proportion of the female deliveries were significantly higher than the males in the lbw group (p 35 years of age, lbw delivery distribution were 4.5%, 85%, 10.5% respectively. similarly, no statistical difference was found for the comparison of the mothers of those 2500 g versus the lbw deliveries (p=0.07). mode of delivery : among the 19,533 deliveries the mode of delivery in 5831 (29.85%) was cesarean section (c / s). the rate of c / s for 2500gr infants. in contrast to the findings of this study, feresu from zimbabwe reported that 16% of their stillbirths were lbw. since fetal growth restriction and preterm birth are important risk factors for stillbirth, in order to decrease stillbirth rates, efforts should be aimed at reducing lbw deliveries. among 108,486 live births, similarly, although this study also showed male predominance in all deliveries, the probability of the birth of a female infant was significantly higher in lbw group. moreover, similar to the study results of shin, we could not find any gender predominance among vlbw and elbw deliveries. shin and hosain gm showed that maternal age and birth weight were strongly related and infants born to older mothers were heavier. the results of this study were not in parallel with those of the two above - mentioned studies. kayastha reported that the prevalence of lbw among teenage mothers was only 6.3%, contradicting with the assumption that maternal age is a determinant factor of birth weight. we have found the rate of lbw deliveries under the maternal age of 18 years as 4.5% and similar to the conclusion reached by kayastha, we could not find any statistically significant relation between maternal age and birth weight either. although there are several studies from turkey on lbw and stillbirth rates[10, 1922 ], this is the first time any data is gathered pertaining to both lbw and stillbirth rates on a local basis in istanbul. furthermore, the infant population upon which the research data is collected comprises the largest single - center research and the most up - to - date of any case study so far from turkey. the aim of this study is merely to contribute to the literature on the topic by emphasizing differences between various surroundings, and updating on the local lbw and stillbirth rates, as this study represents the local population. although the suburbs where our hospital is located at, took a lot migration from all over turkey over the last few decades, it would be misleading to argue that its results are equally representative of or applicable to the whole of turkish population. in other words, the results of this one center study should not be generalized for the whole region or country. low birth weight and stillbirth rates provide important clues on the status of public health in a given area. while in industrialized countries, the epidemiology of lbw has been extensively studied, in less developed countries reliable data remains limited. this is why the findings of this study are important : even though the lbw and stillbirth rates found are lower than that of most other developing countries, there seems to be a slow but steady increase over time in our district. without taking proper precautions, it is inevitable that neonatal mortality and morbidity rates will eventually tend to rise. we encourage parallel studies to be made in various regions comprising multiple socio - economic backgrounds, so that comparative analyses could be made with newfound results and their general evaluation. furthermore, we look forward to a closer involvement of public health services in the area, both official and otherwise, especially concerning prenatal maternal care. early identification and treatment of the risk factors for stillbirth and lbw deliveries, especially those that are preventable, are indispensable to alleviation. | objectiveprevalence of low birth weight deliveries may vary across different environments. the necessity of determination of regional data prompted this study.methodsinformation of all deliveries from january 2004 to december 2008 was obtained from delivery registry records retrospectively. initial data including birth weight, vital status, sex, maternal age and mode of delivery were recorded using medical files. the frequency of low birth weight, very low birth weight, extremely low birth weight and stillbirth deliveries were determined.findingsamong 19,533 total births, there were 450 (23.04 per 1000) stillbirths. low birth weight rate was 10.61%. a significant increase in yearly distribution of low birth weight deliveries was observed (p<0.001). very low birth weight and extremely low birth weight delivery rates were 3.14% and 1.58% respectively. among 2073 low birth weight infants, 333 (16.06%) were stillbirths. the stillbirth delivery rate and the birth of a female infant among low birth weight deliveries were significantly higher than infants with birth weight 2500 g (p<0.001, or=28.37), (p<0.001) retrospectively. there was no statistical difference between low birth weight and maternal age. the rate of cesarean section among low birth weight infants was 49.4%.conclusionhigh low birth weight and stillbirth rates, as well as the increase in low birth weight deliveries over the past five years in this study are striking. for reduction of increased low birth weight rates, appropriate intervention methods should be initiated. |
in many instances, cardiovascular disease (cvd) is lifestyle related and associated with a number of risk factors that begin the debilitating progression in childhood, particularly obesity, hypertension and smoking [1, 2 ]. judging from the large number of people dying worldwide from cardiovascular diseases, it is now estimated that 25 million people will die from these diseases by 2025, unless significant prevention efforts can halt this rise. the world health organization (who) calls cardiovascular disease (cvd) one of three neglected global epidemics. during the past half - century, many epidemiological studies have consistently documented reduction in the incidence of coronary artery disease (cad) events in the more physically active and fit subjects. studies have demonstrated that the most sedentary individuals generally have cad rates twice as often as physically active individuals. as activity levels increase, the rates of cad tend to decrease [6, 7 ]. it can be concluded, then, that physical activity reduces the incidence of cad. physical activity both prevents the development of disease and helps treat many established risk factors, such as elevated blood pressure, insulin resistance and glucose intolerance, elevated triglyceride concentrations, low high - density lipoprotein cholesterol (hdl - c) concentrations, and obesity. exercise in combination with weight reduction can decrease low - density lipoprotein cholesterol (ldl - c) concentrations and limit the reduction in hdl - c that often occurs with a reduction in dietary saturated fat. the catch, chic and heart smart programs are all school - based cardiovascular - based intervention programs that have achieved a change in risk factors. it is increasingly recognized that individual values, beliefs and behavior operate within a social context, like the school and home environment. there is evidence of decreased perceived health risk following public health, physical and social interventions to improve health, suggesting that programs of this type should be considered by school administrators when planning school - based health promotion interventions. there are various ways to present knowledge and gather information that can play an important role in the policy formation process. consideration should always be given to these procedures because public health and health promotion issues should always be addressed when changing policy and considering concepts of interactive and critical knowledge in addition to scientific knowledge. the development of a meaningful health policy should involve an acceptance of these various avenues for disseminating knowledge and instituting frameworks that encourage professionals and citizens to work together to develop and achieve public health and health promotion goals. the objective of this study was to implement a cardiovascular disease information intervention program for school aged students and to test the students knowledge of basic cardiovascular disease information. the ultimate goal was to determine if a carefully structured training program administered to high school students could increase their knowledge about cardiovascular disease and provide them with effective strategies for eliminating or reducing risk factors that are preventable. the study took the form of a prevention program aimed at examining knowledge gains of students with the intention of ultimately implementing a comprehensive prevention module. the procedures included a needs assessment, intervention, pre - test and post - test evaluation phases. prior to the development of the prevention program, a meeting was held with staff and teachers of a local school district where all members of the staff present were surveyed for information on student practices, organization policy toward student risk behaviors, frequency of contact with the target age group and willingness to undertake health promotion activities. based on the results of this teachers survey, it was decided to develop a prevention / intervention program incorporating information about cardiovascular disease and risk factors for developing such diseases. it was decided that prior to the development and implementation of this comprehensive health information intervention, a pilot study should be convened where students would be exposed to information about hypertension and would be given the opportunity to display their knowledge by participating in a pre - test and a post - test. this pilot study was undertaken during a weekend conference with students who were participating in a developmental program at a mississippi college. the subjects for this study were 50 upward bound students enrolled in the mississippi college weekend and summer workshops. the upward bound math and science program is a federally funded, pre - college enrichment program designed to generate skills and motivation in mathematics and science for success in education beyond high school. the program concentrates on young people from disadvantaged backgrounds who have an academic need and a desire to attend a post - secondary institution. the students enrolled in the program represented 10th and 11 grade students from schools in nine counties in the state of mississippi (copiah, hinds, issaquena, leake, madison, sharkey, simpson, washington and yazoo counties). in addition to the academic training received, students were required to attend lectures on other issues that affect their lives, and so they were required to attend lectures and training in prevention of cardiovascular diseases where they were provided information on risk factors for chronic diseases, types of prevention behaviors and practices they could adopt for improving the quality of their lives. prior to the beginning of the training, students were given a pre - test to test their knowledge on issues relating to high blood pressure. after the training was completed, the students were again tested to assess whether their knowledge had changed after exposure to the new information presented as part of the prevention activities. it was hypothesized that students, who were exposed to training about chronic disease and disease prevention, would increase their knowledge, measured by comparing changes in the results of the pre - test and the post - test. the students were administered a short five - item survey that asked questions about high blood pressure, the numbers used to classify high blood pressure, and what is a normal blood pressure reading. they were also asked to respond about their knowledge about one risk factor for heart disease. this survey sought to test the knowledge of this target population. the information program which served as the intervention allowed the students to actively participate in an information session during which they were provided with information and training on issues relating to high blood pressure, important measurements to help them monitor their cardiovascular health, and general cardiovascular disease prevention behaviors. the subjects for this study were 50 upward bound students enrolled in the mississippi college weekend and summer workshops. the upward bound math and science program is a federally funded, pre - college enrichment program designed to generate skills and motivation in mathematics and science for success in education beyond high school. the program concentrates on young people from disadvantaged backgrounds who have an academic need and a desire to attend a post - secondary institution. the students enrolled in the program represented 10th and 11 grade students from schools in nine counties in the state of mississippi (copiah, hinds, issaquena, leake, madison, sharkey, simpson, washington and yazoo counties). in addition to the academic training received, students were required to attend lectures on other issues that affect their lives, and so they were required to attend lectures and training in prevention of cardiovascular diseases where they were provided information on risk factors for chronic diseases, types of prevention behaviors and practices they could adopt for improving the quality of their lives. prior to the beginning of the training, students were given a pre - test to test their knowledge on issues relating to high blood pressure. after the training was completed, the students were again tested to assess whether their knowledge had changed after exposure to the new information presented as part of the prevention activities. it was hypothesized that students, who were exposed to training about chronic disease and disease prevention, would increase their knowledge, measured by comparing changes in the results of the pre - test and the post - test. the students were administered a short five - item survey that asked questions about high blood pressure, the numbers used to classify high blood pressure, and what is a normal blood pressure reading. they were also asked to respond about their knowledge about one risk factor for heart disease. this survey sought to test the knowledge of this target population. the information program which served as the intervention allowed the students to actively participate in an information session during which they were provided with information and training on issues relating to high blood pressure, important measurements to help them monitor their cardiovascular health, and general cardiovascular disease prevention behaviors. the data were analyzed using spss and the students information was reported in the form of frequencies and percentages. the paired t - test was computed to examine the students responses for differences between the pre - test and the post - test that could be attributed to exposure to the training provided. of the 50 students who agreed to participate in the program, 39 of them provided both pre and post tests that were usable for analysis in this study. at follow - up, most of the students showed significant gains in cardiovascular disease knowledge on the target topics covered in the curriculum (table 1). when asked what disease is known as the silent killer ? 87.2 % of the students did not know the answer on the pre - test, whereas 94.9% of them answered correctly on the post - test. there were 5.1% of the students who did not appear to have benefited from the intervention program, however. students were also asked what is the top number of blood pressure called ? none of them knew the answer to this question in the pre - test, but 64.1% of them had the correct answer on the post - test. there were 36.1% of them who did not know the answer to this question. on the question what is the bottom number of the high blood pressure called ?, again, none of them knew the answer on the pre - test, while 64.1% of them answered correctly on the post - test. there were 36.4% of them who still did not know the answer after the intervention. none of them knew the answer to this question on the pre - test, while 84.6% of them gave the correct answer on the post - test : 15.6% of them did not have the right answer, even after being exposed to the intervention. when students were asked to name two diseases that are related to the presence of high blood pressure, only 10.3% of them could do so on the pre - test, while 87.2% of them had improved knowledge on the post - test. still, 12.8% of the students did not improve from the pre - test to the posttest. table 2 is a presentation of the paired t - test that was computed to test for differences between the pre - test and post - test scores of the students. on the question what disease is known as the silent killer ?, significant differences were found between the pre - test scores and the post - test scores of the students (p < 0.05). the significance level computed was p = 0.000. what is the top number of blood pressure called ?, significant differences were found between the pre - test scores and the post - test scores of the students (p < 0.05). the significance level computed was p = 0.000. what is the bottom number of the high blood pressure called ?, significant differences were found between the pre - test scores and the post - test scores of the students (p < 0.05). the significance level computed was p =.000. significant differences were found between the pre - test scores and the post - test scores of the students (p < 0.05). the significance level computed was p = 0.000. name two diseases that are related to the presence of high blood pressure ?, significant differences were found between the pre - test scores and the post - test scores of the students (p < 0.05). the significance level computed was p = 0.000. this study demonstrated that students can become knowledgeable about health risk factors and preventive measures through guided, supervised exposure to instruction that specifically addresses health concerns. these findings support the efforts of many organizations, including the centers for disease control and prevention (cdc) that have begun to advocate the development of action plans designed to help children respond responsibly to these health concerns. these action plans must address various approaches and must incorporate information exchange with students within their academic curriculum, in order to be effective in reducing cardiovascular diseases, particularly among groups like african americans, who suffer disproportionately from the effects of these diseases. the data examined in this study show that adequate training could be a key element in all cvd prevention programs for prevention activities to be effective and sustainable in the long run. the exposure of the students to the information program after the pre - test and the subsequent increases in knowledge about hypertension demonstrated that health promotion could become a successful component of school policy and public policy, and specific lifestyle targets should be set for children regarding other risk factors such as smoking, diet and exercise, practices and behaviors over which they have total control. it is hoped that health promotion activity would become a compulsory part of general school activities. this study shows that it is feasible to deliver an effective prevention program by addressing students daily negative practices in school and at home. it is also believed that the students understanding of the association between those practices and the occurrence of negative cardiovascular outcomes could possibly lead to a reduction of such outcomes. | the objective of this study was to test students knowledge of cardiovascular disease information and to determine if a carefully structured training program administered to high school students would increase their knowledge about cardiovascular disease and risk factors that are preventable. a pilot study was conducted during which fifty high school students from nine counties in the state of mississippi were measured for their knowledge of hypertension both at baseline and after the completion of an intervention training activity. there were significant gains in knowledge between the pre - test and the post - test that the students completed. the gains in knowledge indicate that elimination of risk factors is possible if all health care and school - based prevention programs are implemented to positively impact changes in eating and physical activity behaviors. students involvement in such activities could translate into significant changes in risk factors at these ages and throughout their lifetime. it is widely accepted that these behavioral changes, if sustained into adulthood, could have the potential to influence cardiovascular risk reduction. |
only relatively recently in the history of medicine, was there a need to demonstrate quality of evidence and strength of recommendations to validate treatment effectiveness.13 such support has been provided for various treatments of acute pain with opioids.4 opiates have been used for treatment of acute and persistent pain for centuries, before the current standards of evidence quality became the norm. compared to this, the treatment of chronic nonmalignant pain with opioids is a relatively new development. for the period 19832012, pubmed has more than 2,000 articles on the opioid treatment of chronic nonmalignant pain, but almost no articles on this topic before then. in regards to the bonica pain clinic treatment practices from 19601980, loeser wrote that it did not enter our minds that there could be a significant number of chronic pain patients who were successfully managed with opioids, because if there were any, we almost never saw them.5 this explains the almost complete absence of publications on the opioid treatment of chronic pain before 1983. the value of opioids in the treatment of chronic pain attributable to cancer was well recognized before the 1980s. as far as nonmalignant chronic pain is concerned, several initial publications were collected and summarized in the mid-1980s.12 the use of opioids for chronic pain management was introduced when the new standards of evidence - based medicine were already in the final stages of their establishment. despite this, the opioid treatment of chronic pain came into practice without convincing proof of effectiveness. since then, doubts about the effectiveness and safety of long - term treatment of chronic nonmalignant pain with opioids have been expressed in several reviews.69 the goal of the present study was to test the following hypotheses : (1) there is no strong evidence - based foundation for the conclusion that long - term opioid treatment of chronic nonmalignant pain is effective ; and (2) the risk of addiction the main problem associated with the safety of such treatment has been neglected. the articles were collected mainly using the national library of medicine s pubmed website (http://www.ncbi.nlm.nih.gov/pubmed). keywords related to chronic pain (chronic pain or neuropathic pain) were added to the terms related to opioids (opioids or narcotic analgesics or morphine). in addition, cancer pain and terminal illness were excluded from the search by placing in the search box the following : not (cancer pain or terminal illness). boolean operations were used, in which the following variables were selected : keywords, years of publications, and type of publications. in addition to the electronic search of articles, related publications were also searched manually in the reference lists of reports and reviews. articles found in the searches were reviewed to make sure that they fit the definition of chronic pain. articles with titles that lacked certain indication of pain duration, such as persistent, persisting, or long - term were checked and included in the database only if the duration of pain was 3 months. criteria for excluding articles were : (1) inclusions of cases with malignant pain ; (2) inclusions of treatments combining opioids with local anesthetics or antidepressants ; (3) duration of treatment of 1 day (or 3 months (table 1). the longest randomized investigation (16 weeks) was limited by being an open study.65 all studies with opioid treatment 6 months (table 2) were conducted without a proper control group;64 therefore, they do not provide the consistent good - quality evidence to support a strong clinical recommendation.13 systematic reviews on opioid treatment of chronic nonmalignant pain have concluded that there is insufficient evidence to make a definite conclusion on the efficacy of long - term treatment.69 the problem of safety of opioid treatment revealed itself most dramatically in rising numbers of opioid overdose deaths. according to the 2008 national survey on drug use and health (nsduh) sponsored by the substance abuse and mental health service administration (samhsa), there has been at least a ten - fold increase in the medical use of opioids from 19882007.149 in 2007, 11,499 deaths were caused by overdoses of opioids, roughly a four - fold increase compared with 1999. remarkably, even an increase of that size somehow did not trigger a timely response by the medical journals. this phenomenon is especially noticeable if one looks at the number of editorials on death associated with opioid treatment of chronic pain patients. only two editorials on this topic were found (both late, in 20102011), as if there had been no dramatic increase in opioid - related deaths in 19992007. opioid abuse, misuse, and addiction are the main reasons leading to the opioid overdose deaths. somehow the introduction of opioid treatment of chronic nonmalignant pain did not result in editorials on opioid addiction in chronic pain patients : there were five editorials related to this topic, four of them published only in 20032012. compare this with 171 editorials on opioid addiction in general published during this period (table 4). representation for all types of articles (including letters and commentaries) on opioid addiction in the top 20 journals was also insufficient : zero articles in 19932002 (1015 years after the introduction of treatment) and five in 20032012 (table 5). the topic - in - title articles clearly announce the topic under discussion ; however, if the topic is an undesirable problem, authors often try to avoid naming it explicitly in the title. the lack of topic - in - title publications indicates that the topic is a neglected one.150 as indicated in the results of the present study, death associated with opioid addiction in chronic pain patients was not reflected in titles from 19832002 ; in 20032012, it was found in the titles of only four articles (table 7). this tendency also applied to addiction, abuse, misuse, or dependence in opioid treatment of chronic pain. in 19831992, there were only two topic - in - title articles related to opioid addiction in chronic pain patients, at a time when there were 536 topic - in - title articles on opioid addiction in general (right side of table 6). there were also profound differences in the numbers of addiction articles related specifically to chronic pain patients and to opioid addiction in general for the periods 19932002 and 20032012. especially interesting was the decrease in the number of topic - in - title articles on opioid addiction in general during 19832002 (right side of table 6) when opioid treatment for chronic nonmalignant pain was being introduced. could the acceptance of this new indication for opioid treatment be responsible for such a change ? hojsted and sjogren reported that the rates of addiction associated with long - term opioid treatment were 0%50% in noncancer patients and 0%7.7% in cancer patients, depending on the subpopulation studied and the criteria used.108 this uncertainty is similar to that with the rate of iatrogenic addiction in patients treated with opioids for acute or subacute pain. it is not known whether the risk for iatrogenic addiction among patients treated with opioids for acute or subacute pain is relatively high (> 10%) or low (0.1%).151 the difficulty of estimating the risk of opioid addiction and abuse (see jamison)152 calls into question the accuracy of reported rates of risk for opioid addiction. one author of a study on the use of opioids in chronic nonmalignant pain has asked : is this treatment a lifetime sentence?153 if not, another question should be : has the withdrawal syndrome after long - term opioid use been adequately studied ? ; and not only acute withdrawal syndrome, but protracted withdrawal as well ? the latter (also called protracted abstinence or chronic withdrawal syndrome) is characterized by generalized symptoms (eg, discomfort, fatigue, decreased blood pressure, pulse rate, and body temperature) lasting 39 months.154156 long - lasting (34 months) neurobiological alterations following withdrawal from opioids have been well confirmed in animal experiments.157 lack of knowledge regarding the risk of addiction and even greater uncertainty regarding protracted withdrawal following cessation of long - term opioid treatment of chronic pain call for studies with high - quality evidence that supports reliable recommendations. this study has a limitation related to the absence of exact definition of chronic nonmalignant pain. for example, the international association for the study of pain task force on taxonomy in the classification of chronic pain has chosen not to define chronic pain.158 simple scientometric assessment of articles on long - term opioid treatment of chronic nonmalignant pain indicates the absence of high - quality evidence on efficacy. there is not a single rct study lasting > 3 months (table 1). the longest randomized investigation (16 weeks) was limited by being an open study.65 all studies with opioid treatment 6 months (table 2) were conducted without a proper control group;64 therefore, they do not provide the consistent good - quality evidence to support a strong clinical recommendation.13 systematic reviews on opioid treatment of chronic nonmalignant pain have concluded that there is insufficient evidence to make a definite conclusion on the efficacy of long - term treatment.69 the problem of safety of opioid treatment revealed itself most dramatically in rising numbers of opioid overdose deaths. according to the 2008 national survey on drug use and health (nsduh) sponsored by the substance abuse and mental health service administration (samhsa), there has been at least a ten - fold increase in the medical use of opioids from 19882007.149 in 2007, 11,499 deaths were caused by overdoses of opioids, roughly a four - fold increase compared with 1999. remarkably, even an increase of that size somehow did not trigger a timely response by the medical journals. this phenomenon is especially noticeable if one looks at the number of editorials on death associated with opioid treatment of chronic pain patients. only two editorials on this topic were found (both late, in 20102011), as if there had been no dramatic increase in opioid - related deaths in 19992007. opioid abuse, misuse, and addiction are the main reasons leading to the opioid overdose deaths. somehow the introduction of opioid treatment of chronic nonmalignant pain did not result in editorials on opioid addiction in chronic pain patients : there were five editorials related to this topic, four of them published only in 20032012. compare this with 171 editorials on opioid addiction in general published during this period (table 4). representation for all types of articles (including letters and commentaries) on opioid addiction in the top 20 journals was also insufficient : zero articles in 19932002 (1015 years after the introduction of treatment) and five in 20032012 (table 5). the topic - in - title articles clearly announce the topic under discussion ; however, if the topic is an undesirable problem, authors often try to avoid naming it explicitly in the title. the lack of topic - in - title publications indicates that the topic is a neglected one.150 as indicated in the results of the present study, death associated with opioid addiction in chronic pain patients was not reflected in titles from 19832002 ; in 20032012, it was found in the titles of only four articles (table 7). this tendency also applied to addiction, abuse, misuse, or dependence in opioid treatment of chronic pain. in 19831992, there were only two topic - in - title articles related to opioid addiction in chronic pain patients, at a time when there were 536 topic - in - title articles on opioid addiction in general (right side of table 6). there were also profound differences in the numbers of addiction articles related specifically to chronic pain patients and to opioid addiction in general for the periods 19932002 and 20032012. especially interesting was the decrease in the number of topic - in - title articles on opioid addiction in general during 19832002 (right side of table 6) when opioid treatment for chronic nonmalignant pain was being introduced. could the acceptance of this new indication for opioid treatment be responsible for such a change ? hojsted and sjogren reported that the rates of addiction associated with long - term opioid treatment were 0%50% in noncancer patients and 0%7.7% in cancer patients, depending on the subpopulation studied and the criteria used.108 this uncertainty is similar to that with the rate of iatrogenic addiction in patients treated with opioids for acute or subacute pain. a systematic review on this topic concluded, it is not known whether the risk for iatrogenic addiction among patients treated with opioids for acute or subacute pain is relatively high (> 10%) or low (0.1%).151 the difficulty of estimating the risk of opioid addiction and abuse (see jamison)152 calls into question the accuracy of reported rates of risk for opioid addiction. one author of a study on the use of opioids in chronic nonmalignant pain has asked : is this treatment a lifetime sentence?153 if not, another question should be : has the withdrawal syndrome after long - term opioid use been adequately studied ? ; and not only acute withdrawal syndrome, but protracted withdrawal as well ? the latter (also called protracted abstinence or chronic withdrawal syndrome) is characterized by generalized symptoms (eg, discomfort, fatigue, decreased blood pressure, pulse rate, and body temperature) lasting 39 months.154156 long - lasting (34 months) neurobiological alterations following withdrawal from opioids have been well confirmed in animal experiments.157 lack of knowledge regarding the risk of addiction and even greater uncertainty regarding protracted withdrawal following cessation of long - term opioid treatment of chronic pain call for studies with high - quality evidence that supports reliable recommendations. this study has a limitation related to the absence of exact definition of chronic nonmalignant pain. for example, the international association for the study of pain task force on taxonomy in the classification of chronic pain has chosen not to define chronic pain.158 there is no high - quality evidence on the efficacy of long - term opioid treatment of chronic nonmalignant pain. as a result, the safety of opioid treatment in terms of risk of addiction and overdose death has not properly been assessed due to the complexity of these outcomes. until 2003, opioid addiction associated with the treatment of chronic nonmalignant pain was clearly a neglected topic of publication. | backgroundfor the past 30 years, opioids have been used to treat chronic nonmalignant pain. this study tests the following hypotheses : (1) there is no strong evidence - based foundation for the conclusion that long - term opioid treatment of chronic nonmalignant pain is effective ; and (2) the main problem associated with the safety of such treatment assessment of the risk of addiction has been neglected.methodsscientometric analysis of the articles representing clinical research in this area was performed to assess (1) the quality of presented evidence (type of study) ; and (2) the duration of the treatment phase. the sufficiency of representation of addiction was assessed by counting the number of articles that represent (1) editorials ; (2) articles in the top specialty journals ; and (3) articles with titles clearly indicating that the addiction - related safety is involved (topic - in - title articles).resultsnot a single randomized controlled trial with opioid treatment lasting > 3 months was found. all studies with a duration of opioid treatment 6 months (n = 16) were conducted without a proper control group. such studies can not provide the consistent good - quality evidence necessary for a strong clinical recommendation. there were profound differences in the number of addiction articles related specifically to chronic nonmalignant pain patients and to opioid addiction in general. an inadequate number of chronic pain - related publications were observed with all three types of counted articles : editorials, articles in the top specialty journals, and topic - in - title articles.conclusionthere is no strong evidence - based foundation for the conclusion that long - term opioid treatment of chronic nonmalignant pain is effective. the above identified signs indicating neglect of addiction associated with the opioid treatment of chronic nonmalignant pain were present. |
latent m. tuberculosis infection (ltbi) represents a considerable reservoir of future active disease and contagion. risk factors include co - infection with human immunodeficiency virus (hiv), diabetes mellitus, low body weight, old age, or use of immunosuppressive medications. in immunocompetent individuals, the annual risk of progression preventing ltbi individuals from reactivation (before they become symptomatic and infectious) may constitute a major step towards the elimination of tb. therefore, the revised global plan to stop tb (201115) has set 2015 as the goal for point - of - care tests that can be used for the accurate detection of preclinical tb. bacterial load is associated with disease risk, and antibody levels against m. tuberculosis components may be biomarkers for load as well as disease risk [46 ]. stratification of tb suspects into groups of absent, low (smear - negative tuberculosis), and high (smear - positive tuberculosis) bacterial burden showed that antibody levels correlated with bacillary burden. in the same study, data of the macaque model, which reproduces key features of latent tb in humans, showed that infection outcome was reflected by the antibody response in the latent infection group, thereby confirming previous animal studies [79 ]. although studies were small, increased specific antibody levels during the ltbi stage in humans also characterized progressors [5, 6 ]. antibody - based tests for the diagnosis of active tb disease are often criticized for their lack of specificity in tb endemic regions, which is due to a high background prevalence of ltbi. clearly, further research is needed to elucidate whether m. tuberculosis specific antibody tests can determine active tb and cases at risk for progression and whether lack of specificity of antibody - based tb tests will turn out to be due to a high risk for an early stage of progression to active tb. the low frequency of reactivation in immunocompetent ltbi individuals poses a challenge for the discovery of prognostic markers. therefore, we chose to investigate the distribution of serologic responses, as a nonrandom distribution may point to a subgroup with higher bacterial load and an increased risk for future progression to disease. in a south african tb endemic population, we evaluated the serodiagnostic reactivity of l - alanine dehydrogenase (aladh) (rv2780), nitrate / nitrite response transcriptional regulator narl (rv0844c), periplasmic phosphate - binding lipoprotein psts3 (rv0928), 19 kda lipoprotein antigen precursor lpqh (rv3763), and lipoprotein mpt83 (rv2873). igg responses to each of the two surface - exposed lipoproteins, 19 kda and mpt83, are predominantly recognized in active tb sera and not in non - tb disease (ntbd) sera. the 19 kda antigen promotes binding to host cells and phagocytosis of mycobacteria, inhibits ifn--induced killing of mycobacteria by macrophages, and induces macrophage apoptosis. mpt83 elicits t cell proliferation of the majority of tb patients and is being considered as future subunit vaccine candidate. the third lipoprotein, m. tuberculosis psts3, which is involved in active transport of inorganic phosphate across the membrane (import), has not been investigated yet in subjects with ltbi for the serodiagnosis of m. tuberculosis. however, psts3 generates ifn--producing cells in a more potent manner than the closely related 38 kda (psts1), a major m. tuberculosis antigen [4, 18, 19 ]. the in tb serodiagnostics newly investigated protein antigen narl is a putative nitrate response regulator involved in the regulation of anaerobic metabolism and is part of the membrane fraction of m. tuberculosis. igg responses to the culture filtrate (and membrane) protein aladh are unable to distinguish untreated tb patients and controls in endemic settings. aladh is present in m. tuberculosis but not in the vaccine strain mycobacterium bovis bcg [21, 23 ]. it may play a role in cell wall synthesis as l - alanine is an important constituent of the peptidoglycan layer. we focused on iga antibodies because m. tuberculosis - specific iga antibodies discriminated better than igg antibodies between active tb and tb endemic controls in africa as well as between healthy close contacts of pulmonary tb patients and healthy individuals without such contact. moreover, iga production was reported to be highly t - cell dependent, and a protective role for iga was suggested in several murine models of mycobacterial infection, for example,. sera utilized to probe antibody assays were from a retrospective serum bank collected from individuals in an epidemiological field site in metropolitan cape town in south africa with a population of whom 99.7% are of mixed race. the incidence of new smear - positive tb in this community was 341/100 000 population in 2002 and the majority of people harbours latent infection. in the study community, bcg vaccination (danish strain, 1331, statens serum institute, copenhagen, denmark) is routinely administered at birth since 1971. the study was approved by the ethics committee of the faculty of health sciences at the stellenbosch university and written informed consent was obtained from all participants or their legal guardians in the case of children. inclusion criteria for all healthy control participants enrolled into the study were residence in the described community, absence of clinical signs of tb or other diseases, absence of prior tb, hiv negativity, and no pregnancy. several parameters were employed to determine tb infection status : the mantoux skin test, two different and independent commercial interferon- release assays (igras) [the quantiferon tb gold in tube (qft) (qiagen, hilden, germany, australia) and t-spot.tb (oxford immunotec, abingdon, uk) ], chest x - ray (cxr), and sputum afb staining. we used > 15 mm as cut off for mantoux test positivity and alternatively > 5 mm as described in more detail in the results section. two igras were used, as rates of positive results have been reported to differ between t-spot.tb and quantiferon - tb gold (e.g. [31, 32 ]). sixty - four consecutively recruited recent household contacts of active tb patients were part of a larger household contact study, and because the non - ltbi individuals constituted fewer than 20% of the contacts, three additional community controls with no known previous tb exposure were added and underwent the same investigations as the household contacts except the igra assays. the majority of ltbi subjects were followed up for the development of active tb disease within 2 years after their first recruitment, and one progressor (after 3 months) was identified according to hospital records. forty - two hiv - negative, ziehl - neelsen sputum smear - positive and bactec sputum culture - positive active pulmonary tb patients with no known multidrug resistance that were part of the same larger study as the controls, of which results have been published recently [33, 34 ], were included. seven tb patients were excluded due to hiv - seropositivity (n = 1), ntm infection (n = 2), or concomitant illness, such as diabetes mellitus (n = 4). all tb patients were self - reporting, untreated cases, and all except 2 had a first episode of active tb. blood samples of control subjects and tb patients (at diagnosis prior to initiation of treatment) were taken. after transport of the blood samples to the laboratory (within 2 h of collection and at ambient conditions), serum was separated by centrifugation (1250 g for 7 min) and stored in aliquots at 80c until use. the production of the functional m. tuberculosis l - alanine dehydrogenase (aladh) in the heat - induced strain escherichia (e.) coli cag629 (pmsk12) has been described previously. for cloning, the genes of the remaining 4 protein antigens (table 1) were amplified by pcr using primers with integrated restriction sites allowing the site - directed insertion of cleaved pcr - products into pet vectors (novagen). all four genes were fused to sequence coding for 6-fold his - tag (table 1). the genes were expressed in e. coli bl21(de3) or in case of psts3 in e. coli rosetta (de3). the antigens were purified using standard chromatographic methods (affinity chromatography, ion exchange chromatography, size exclusion chromatography). insoluble antigens were solubilized (refolded) from denaturating conditions (8 m urea) into buffers free of choatropic reagents. further details regarding the protein purification are described in the supplements (see supplementary material available online at http://dx.doi.org/10.1155/2015/364758). microtiter plates were coated with m. tuberculosis antigens and serologic antibody responses were determined using standard procedures as described in the supplements. laboratory personnel performing the serodiagnosis assays were blinded to the clinical status of the patients or the controls. subsequent record reviews were done by clinical staff to classify the individuals into clinical groups without knowledge of the serologic response phenotype. graphpad prism (graph pad, san diego, ca, usa) was used to create graphs and statistical analyses were performed using medcalc software (kagi, berkeley, ca). the t - test for independent samples or the mann - whitney test was used for the statistical comparison of 2 groups depending on the fact whether or not the data were normally distributed. given the aim to develop a diagnostic test for tb with a specificity level above at least 90%, the experiments were analyzed by using specificity levels of 90%, as was done by other investigators [36, 37 ]. the spearman rank test was used for correlation analyses. generally, a two - tailed p value of p 0.05 was considered significant. sixty - four healthy household contacts of recently (within past 2 months) diagnosed active pulmonary tb patients underwent tst and 2 commercial igra tests, qft, and t-spot.tb. fifty - three household contacts were classified as ltbi due to positivity in tst (induration 15 mm), qft and/or t-spot.tb (n = 53 ; age range : 1559 years ; 58.2% females). as noninfected control individuals were rare in the described tb endemic settings, we added 3 healthy nonhousehold contacts (community controls with no known previous tb exposure) with tst - indurations of 0 mm, normal chest x - rays and afb - negative - assisted sputum samples to the healthy control group in order to increase the statistical power (n = 14 ; age range : 10.755.2 years ; 71.4% females). the mantoux induration > 15 mm criterion was used for the definition of ltbi, as a large - scale study performed in a rural african population showed that the local environmental mycobacterial exposure is reflected in mantoux indurations that cluster around 10 mm, whereas the m. tuberculosis exposures are reflected by indurations with a mode at 1517 mm or larger. still, the exact definition of the ltbi status is hampered by the lack of a gold standard. according to centers for disease control and prevention (cdc) criteria mantoux induration > 5 mm of recent tb household contacts can be considered as ltbi, and we alternatively considered this cut off for defining a positive tuberculin reaction : of the fourteen members of the original hc group, two subjects had mantoux indurations between 5 mm and 15 mm, and both individuals had negative igra results. therefore, in an alternative grouping of the controls, we transferred the 2 igra - negative individuals with mantoux indurations between 5 and 15 mm from the hc group (hc : n = 12) into the ltbi group (ltbi : n = 55). the 42 smear - positive active pulmonary tb patients (age range : 1855 years ; 40.5% females) included in this study were recruited from the same community as the control participants. the 5 protein antigens narl, aladh, 19 kda, psts3, and mpt83 (table 1) were cloned and expressed in e. coli and purified using standard chromatographic methods. a coomassie brilliant blue r-250 stained sds - page analysis of the 5 proteins is shown in figure 1. the 109 serum samples derived from 42 pulmonary tb patients, 53 ltbi controls, and 14 non - ltbi controls were tested in a blinded fashion for iga responses specific to the 5 proteins as well as for igg responses to aladh. among controls, we found that elevated iga levels against the investigated 5 antigens were not randomly distributed but concentrated on a subgroup of 28.4% (n = 19)with particular high levels in a subgroup of 4.5% (n = 3), which comprised the progressor from latent infection to active tb. to graphically distinguish between those ltbi individuals with negative serum data (more than 70% of the controls) and those with moderately elevated and highly elevated serology, we used the mean ranks of iga signals against the 5 antigens investigated to divide the ltbi subjects into the 3 subgroups ltbi (low iga), ltbi (medium iga) and ltbi (high iga) (figure 2). furthermore, we statistically compared the non - ltbi controls with either the active tb patients or the ltbi subgroup with elevated iga signals comprising the 2 subgroups ltbi (medium iga) and ltbi (high iga) (table 2). based on a cut - off referring to the 92.9-percentile of the healthy non - ltbi controls [92.9% (95% ci, 66.199.8%) specificity ], the iga response against the novel protein antigen narl achieved with 81% (95% ci, 65.991.4%) the highest sensitivity for the detection of active tb patients, followed by anti - aladh iga with 76.2% (95% ci, 60.587.9%) sensitivity and anti-19 kda iga with 64.3% (95% ci, 48.078.4%) sensitivity (table 2). moreover, based on a specificity of 100% (95% ci, 76.8100%), anti - narl iga and anti - aladh iga both detected 84.2% (95% ci, 60.496.6%) of the ltbi subgroup with elevated iga signals, followed by anti-19 kda iga with 78.9% (95% ci, 54.493.9%) sensitivity (table 2). anti - narl iga, anti-19 kda iga, and anti - aladh iga detected the ltbi (high iga) subgroup, which comprised the progressor to active tb, with a distinct signal - to - noise ratio compared to the non - ltbi community controls (figures 2(a), 2(b), and 2(f)). in contrast, the ltbi (high iga) subgroup was indistinguishable from the non - ltbi community controls when using the igg response to aladh (figure 2(e)). very similar results to those shown in table 2 were obtained when using the alternative groups hc and ltbi (table s1). when testing for correlations between the antibody od values in ltbi sera (n = 53) (table 3 and figure 3), we found strong correlations between the iga responses and the 5 protein antigens [strongest correlation between anti - aladh iga and anti-19 kda iga : spearman 's r = 0.96 (95% ci, 0.930.98) ; p < 0.0001 (figure 3(a)) ; weakest correlation between anti - narl iga and anti - psts3 iga : r = 0.82 (95% ci, 0.710.89) ; p < 0.0001 (figure 3(d)) ]. in contrast, we found no or negligible correlations of any of the iga responses with the exemplarily tested igg response to aladh [e.g., no correlation between anti - aladh iga and anti - aladh igg : r = 0.21 (95% ci, 0.060.46) ; p = 0.128 (figure 3(c)) ] (table 3). very similar results to those shown in table 3 were obtained when using the alternative group ltbi (table s2). in recent years it became increasingly clear that antibody - based diagnostics of active tb (often developed and tested in non - tb endemic countries) performed poorly in tb endemic settings due to high background signals of antibodies in ltbi individuals. in our study we also found that the presence of ltbi affected identification of active tb by serology. in particular, we found that among controls elevated iga levels against the investigated 5 antigens were not randomly distributed but concentrated on a subgroup of < 30%with particular high levels in a small subgroup of ~5%. the consistently elevated iga levels in a subgroup of controls suggest higher mycobacterial load, a risk factor for progression to active tb. whether high iga and/or igg levels have prognostic potential should be investigated in future large scale studies. in several previous reports it has indeed been suggested, directly or indirectly, that progression to active tb may be predicted by increased specific antibodies levels. certain tb - specific antibody responses decline significantly during successful therapy (and the time thereafter) when both bacterial load and risk of disease also decline [38, 39 ]. in inactive tb (defined by a positive response to the tst, negative sputum cultures, and abnormal but stable cxr findings), a special form of latent infection known to have increased risk of active tb, elevated specific antibody responses have been reported [40, 41 ]. several independent studies showed that antibody responses to mycobacterial proteins were detectable months to years prior to the diagnosis of tb in persons infected with hiv, for example,, again suggesting that in vivo m. tuberculosis replication may begin long before progression to active tb becomes clinically detectable. specific antibacterial antibodies have been shown to be present in sera obtained from m. tuberculosis h37rv aerosol - infected rabbits, and guinea pigs both with preclinical tb [7, 8 ]. in mouse models of m. avium infection, susceptibility to infection correlated with increased synthesis of specific anti - bacterial antibodies. integration of macaque and human proteome - scale antibody profiling data revealed dynamic characteristics of the antibody response in relation to bacillary burden and infection outcome. two individuals with elevated specific igg responses originally categorized as ltbi were subsequently diagnosed to have culture - confirmed active tb within a few weeks of the serologic testing. moreover, among apparently healthy professional contacts of tb patients (or pathological specimens thereof), elevated specific igg and/or igm responses to mycobacterial antigens were determined in a subgroup of 9 individuals, of whom 4 (44.4%) developed active tb within one year after serological testing. clearly, future large scale, long term prospective studies in different tb endemic areas are needed to further evaluate and substantiate the validity of the hypothesis that certain specific anti - mycobacterial antibody responses are predictors of future active tb. if true, the reported low specificity of serodiagnostics for the detection of active tb would turn out to be due to a high risk for an early stage of progression to active disease and would then offer new opportunities to interrupt the cycle of transmission. if our findings are confirmed the clinical relevance would be as follows : a corresponding antibody - based test in endemic settings would then not differentiate between active tb cases on the one hand and latent or absent infection on the other hand. instead, it would distinguish a high - risk group for preclinical or active tb from a group that is unlikely to progress to clinical disease. this would be of particular significance as such antibody tests could be developed into low - cost, point of care tests that may be used as screening tools, particularly in high tb burden low - resource settings. in such a clinical approach, the pre - screened high risk individuals could then be investigated using established assays such as x - ray, igra, sputum smear, sputum culture and genexpert mtb / rif for final clinical assessment [3, 42 ]. concerning the serodiagnostic results, those ltbi individuals showing the highest iga or igg antibody signals might have the highest risk to progress to active tb as their higher antibody levels may indicate higher bacterial loads. the detection of preclinical and early tb would have considerable clinical impact, as the identification, close monitoring, or early treatment of those ltbi with incipient disease would offer an opportunity to break the cycle of transmission and to prevent more serious lung destruction. in addition, early treatment of ltbi may decrease the emergence of multidrug resistance- (mdr-) tb strains, as the low numbers and slow turnover of mycobacteria in ltbi presumably present less opportunity to develop resistance. in the present study the ltbi subject with the highest iga levels against narl, aladh and 19 kda developed active tb within 3 months after recruitment. although this is in line with the working hypothesis, one has to be very careful with its interpretation as we are dealing only with a single case. clearly, as stated above, further research is needed to investigate whether antibody responses to mycobacterial antigens hold any prognostic significance for subsequent development of active tb in individuals with ltbi as previously suggested [46, 8 ]. though a recent metaanalysis showed that so far neither igras nor the tst can discriminate the ~90% of persons with true ltbi from the ~10% who will develop active tb, promising tendencies are noteworthy also in this field [45, 46 ]. subjects with high risk for preclinical tb might be monitored more closely in defined time intervals using the currently best available resources and should be treated where applicable. due to the low frequency of reactivation in immunocompetent ltbi individuals even in tb endemic settings, large - scale longitudinal human studies would have to be conducted to further investigate whether serologic responses to mycobacterial antigens hold any prognostic significance for subsequent development of active tb in individuals with ltbi (correlates of risk). the results of this study and previous human and animal studies [4, 5, 79, 3841 ] suggest that this is a promising approach, particularly as the serological tests could be performed on existing stored sera from previous studies. our results suggest that for these investigations besides igg also iga serology should be considered. due to the important role of iga antibodies in the lung the development of point - of - care tests that can be used as correlates of risk or as diagnostic for active tb would constitute a major advance. in conclusion, as suggested in human studies and several animal models [4, 5, 79, 3841 ], it remains a promising hypothesis that those latently infected individuals with antibody responses resembling those of active tb subjects are more prone to progression to active tb. our finding of a nonrandom distribution of antibody responses among ltbi subjects suggests that the development of serodiagnostic kits for the determination of a high - risk group for preclinical or active tb in endemic settings may be possible. furthermore, our results encourage the further investigation of iga besides igg responses in the field of serodiagnosis of active tb and possibly preclinical tb. moreover, iga antibodies against the novel antigen narl were able to determine, besides the putative high - risk subgroup for preclinical tb (including highest levels for the actual progressor), the highest proportion of active tb patients. | elevated antibody responses to mycobacterium tuberculosis antigens in individuals with latent infection (ltbi) have previously been linked to an increased risk for progression to active disease. studies in the field focussed mainly on igg antibodies. in the present study, iga and/or igg responses to the mycobacterial protein antigens aladh, narl, 19 kda, psts3, and mpt83 were determined in a blinded fashion in sera from 53 ltbi controls, 14 healthy controls, and 42 active tb subjects. among controls, we found that elevated iga levels against all investigated antigens were not randomly distributed but concentrated on a subgroup of < 30%with particular high levels in a small subgroup of ~5% comprising one progressor to active tb. based on a specificity of 100%, anti - narl iga antibodies achieved with 78.6% sensitivity the highest accuracy for the detection of active tb compared to healthy controls. in conclusion, the consistently elevated iga levels in a subgroup of controls suggest higher mycobacterial load, a risk factor for progression to active tb, and together with high igg levels may have prognostic potential and should be investigated in future large scale studies. the novel antigen narl may also be promising for the antibody - based diagnosis of active tb cases. |
type 2 diabetes mellitus (t2 dm) is the most common form of diabetes constituting 90% of the diabetic population. the number of patients with diabetes in india is currently around 40.9 million and is expected to rise to 101 million by 2030. the so - called asian indian phenotype refers to certain unique clinical and biochemical abnormalities in indians which include increased insulin resistance, higher waist circumference despite lower body mass index (bmi), lower adiponectin and higher levels of highly sensitive c - reactive protein levels. chronic complications of diabetes, the major cause of morbidity and mortality, are often present at the time of diagnosis. the problem is further worsened as the diagnosis of diabetes is often delayed from months to years due to lack of symptoms, lack of awareness and the fear of unknown in spite of awareness. a very high prevalence of complications at diagnosis has been reported from various studies across the globe and from parts of india. however, a nationwide indian data for the same is not available. a high prevalence of such complications, if documented, will help to convince the physicians of the importance of screening for these complications in all type 2 diabetics (t2d) at presentation, for appropriate implementation of treatment without delay. the present study was designed to determine the prevalence of complications in newly - diagnosed t2d patients across various regions of india. the present study was a cross - sectional survey done across 14 centers representing north, west, south and east region of india. in this study, adult patients aged 18 years and above, newly - diagnosed with t2 dm for less than 3 months based on the american diabetes association criteria were included. patients who have been diagnosed with diabetes for more than 3 months, patients on any drug therapy, gestational diabetics, and steroid - induced diabetics or those with co - morbid conditions that require prolonged steroid therapy were excluded. cut - off of 87% sensitivity in detecting diabetic poly neuropathy. bp was recorded twice, 10 min apart - both arms, standing and lying down. known hypertensive patients were recorded separately. all baseline high values were retested over a period of 15 days for confirmation of hypertension (> 130/90 mm / hg) to avoid the white coat phenomenon. for diagnosing dyslipidemia, whole lipid profile of the patient was tested in the fasting blood sample. value over and above the goal of therapy (low density lipoprotein (ldl) > 100 mg / dl and total cholesterol > 200 mg / dl) was considered abnormal. ihd diagnosis was made on the basis of treadmill test or coronary angiogram (if resting ecg showed changes) or chest pain relieved by nitrates in cases where patient complained of anginal pain. for anthropometry, bmi cut - off of 25 kg / m for men and 23 kg / m for women was used for making a diagnosis of obesity as recommended by various studies as indians are having asian - indian phenotype.. physician if trained or a retinologist did the fundus examination after full dilatation of the pupil. routine stereoscopic fundus photography was not done as it was not available across the country in all the centers. nephropathy was diagnosed based on 24 h urine collection for proteinuria (mg/24 h). a value of > 300 mg / dl was taken as confirmed nephropathy. twenty four hours collection was carried out by the treating physician taking care of the factors that interfere with proteinuria (like, uncontrolled hypertension, urinary infection etc.). diagnosis of neuropathy was made on clinical grounds for senses of touch, pain, vibration and jerks ruling out all other non - diabetic causes for neuropathy. 128 hz tuning fork for vibration perception and 10-g monofilament pressure sensation at the distal plantar aspect of both great toes and metatarsal joints were carried out along with assessment of ankle reflexes. combination of more than one test has > 87% sensitivity in detecting diabetic poly neuropathy. bp was recorded twice, 10 min apart - both arms, standing and lying down. known hypertensive patients were recorded separately. all baseline high values were retested over a period of 15 days for confirmation of hypertension (> 130/90 mm / hg) to avoid the white coat phenomenon. for diagnosing dyslipidemia, whole lipid profile of the patient was tested in the fasting blood sample. value over and above the goal of therapy (low density lipoprotein (ldl) > 100 mg / dl and total cholesterol > 200 mg / dl) was considered abnormal. ihd diagnosis was made on the basis of treadmill test or coronary angiogram (if resting ecg showed changes) or chest pain relieved by nitrates in cases where patient complained of anginal pain. for anthropometry, bmi cut - off of 25 kg / m for men and 23 kg / m for women was used for making a diagnosis of obesity as recommended by various studies as indians are having asian - indian phenotype. our study is a specialized clinic - based survey rather than population based or epidemiological survey and reflects the prevalence of diabetic complications in the out - patient setting in the current health system of india. the study recruited 4,600 patients with equal contribution from all the centers from june 2006 to october 2011. of the total 4,600 newly diagnosed patients with t2d, majority were male (67%, n : 3,082) in comparison to female (33%, n : 1,518). baseline characteristics in cindi the importance of age on the prevalence of newly diagnosed diabetes shows that the majority of the patients were from the age group 41 - 50 years (40%) as illustrated in figure 1, which shows sex - specific estimates of diabetes prevalence by age. age distribution in cindi the prevalence of diabetes specific micro vascular and ihd are shown in table 2. in patients having diabetic retinopathy, majority (65.9%) were having non - proliferative diabetic retinopathy. prevalence of complications : cindi the prevalence of risk factors for macro vascular disease is shown below in table 3 t2d is an insidious illness with a long preclinical asymptomatic phase during which patients may be exposed to the ill - effects of asymptomatic hyperglycemia for many years before they are diagnosed. the present study reconfirms this and shows that a substantial proportion of patients with t2 dm have evidence of diabetic tissue damage at the time of diagnosis of diabetes. in our study chronic complications in newly diagnosed patients with type 2 diabetes mellitus in india cindi, many patients were from a younger age 31 - 40 years (35%) and almost equal (40%) population was from the age group 41 - 50 years, which confirms similar finding of other studies showing that in developing countries the majority of patients with diabetes are in the age range of 45 - 64 years, whereas age group is higher (> 65 years) in the developed countries. younger age of onset implies that these subjects develop diabetes in the most productive years of their life and have a greater chance of developing complications. both environmental and genetic factors might explain the younger onset of age along with high prevalence of diabetes in the indian population. the indian patients also had a more sedentary life - style and a higher prevalence of family history of known diabetes than the other groups. ramachandran., observed similar findings in their study of parental influence on the spectrum of t2d in the offspring among indians. familial clustering of t2d is well - known and is high in indians, which was also observed in our study with more than half of the patients (64%) having positive diabetes family history for first degree relatives. while the relatively low rate of diabetic retinopathy (6%) in cindi is similar to some of the studies from south india (7.3%) and abroad that include denmark (5%), where they suggested that the low prevalence is due to the danish health system, which is free of charge and results in early diagnosis of diabetic patients. the results for diabetic retinopathy are in contrast to findings of other studies showing higher prevalence in romania (14.37%) and taiwan (25.5%). the prevalence of diabetic retinopathy in newly diagnosed patients among various studies, chennai urban rural epidemiology study (cures) (5.1%) and united kingdom prospective diabetes study (ukpds) (35%) is shown below in figure 2. prevalence of retinopathy in newly diagnosed type 2 diabetes mellitus patients although, it is difficult to identify the reasons for such variation in prevalence rates among various populations, race, age, method of detecting diabetic retinopathy, health - care facilities, and other risk factors could have contributed to the differences. as mentioned in one of the study from india, inherent ethnic difference in the indians in relation to the susceptibility to diabetic retinopathy may be one aspect and another reason may be the type of diet which although rich in carbohydrates includes more vegetables, less fat and perhaps more antioxidants and anti - inflammatory agents like curcumin. overall prevalence of nephropathy in cindi is only 1.02%, which is comparable to other studies from india cures, which showed overt nephropathy in 0.8% but low in comparison to ukpds which showed 7% as shown below in figure 3. it is possible that micro - albuminuria may have been transient considering glycemic control may have modulated the albumin excretion. this question would be addressed in future longitudinal studies prevalence of nephropathy in newly diagnosed type 2 diabetes mellitus patients in cindi prevalence of peripheral neuropathy is 13.15%, which is again comparatively low in comparison to other studies from sri lanka (25.2%) and amsterdam (48.3%). literature search for articles on the prevalence of neuropathy in newly diagnosed t2 dm in india (100 million by 2030, which could translate into a heavy economic burden and compromise the quality of life. this underlines for the high importance of screening of all newly diagnosed t2d patients not only for early detection of micro vascular and macro vascular complications, but also to prevent or retard the progression of complications by aggressive management. beyond screening, education of our high risk population regarding diabetes related complications must be started to encourage earlier medical consultation. medical stakeholders must be encouraged to formulate new guidelines as to how aggressive physicians should be in diagnosing and managing diabetes in indian population. | background : prevalence of diabetes is on an increase in india, currently there is limited nation - wide data regarding the prevalence of chronic complications in diabetic patients at diagnosis. this information will help health - care professionals approach management more aggressively to prevent complications.objective:to determine the prevalence of chronic complications in newly - diagnosed type 2 diabetic (t2d) patients in india.design and methods : this was a cross - sectional survey of t2d patients, diagnosed within 3 months of their first visit to the centers doing the survey. each patient was screened for diabetic complications, hypertension, dyslipidemia, and body mass index. family history was recorded. standard protocols were used to make the diagnosis of retinopathy, neuropathy and nephropathy. data analysis was carried out using the standard statistical techniques.results:of the total 4,600 (males 67%, females 33%) newly diagnosed patients with t2d, majority were from the age group 41 - 50 years (40%). 13.15% of newly detected india t2d had neuropathy 6.1% had retinopathy and 1.06% had nephropathy. risk factors of macro vascular complication such as hypertension, obesity, and dyslipidemia were observed in 23.3%, 26%, and 27% of patients respectively. ischemic heart disease was noticed in 6%.conclusion : high prevalence of micro vascular complications was present at diagnosis along with association of cv cardiovascular risk factors among indian t2d. in view of this, screening must be instituted for all diabetics for complications at the time of diagnosis itself. |
outbreak a occurred during april and may 2000 ; at least 129 cases were laboratory confirmed. outbreak c occurred in april 2001 ; at least 230 people were infected (79 ; unpub. an outbreak patient was defined as a person with microscopically confirmed cryptosporidium infection who became ill during the outbreak period and who was a resident in the water supply areas. the attack rates for outbreaks a, b, and c were 34, 180, and 58 cases/100,000 persons, respectively. outbreak b was thought to be caused by the ingress of human sewage from a septic tank into the drinking water - distribution system and c from the ingress of wastewater from a blocked drain. for molecular analysis, 34, 42, and 44 microscopically positive stool samples from outbreaks a, b, and c, respectively, were used. fourteen control isolates were from sporadic c. parvum infections of the bovine genotype in a rural area in west ireland about 100 miles from belfast, and the water supply was entirely different. ten control isolates were from sporadic c. parvum infections of the human genotype in northwest england during the same time as outbreak c. c. parvum genotype in human fecal samples was first determined by a cowp gene - based pcr - rflp tool (10). the oocysts were washed and resuspended in deionized water and stored at 4c before use. to extract dna, oocyst suspensions were incubated at 100c for 60 minutes, digested with proteinase k (3 mg / ml) in lysis buffer at 56c for 30 minutes, and extracted by spin - column filtration (qiamp dna kit, qiagen, crawley, uk). genotypes were investigated by using the cowp gene primers cry15 and cry9 to amplify a 553-bp region, which was then subjected to endonuclease digestion by rsai (10). genotypes were confirmed by using an ssu rrna - based pcr - rflp tool (12). subgenotyping was done by sequence analysis of the gp60 gene (13). before molecular analysis, the wastewater sample was processed by both salt flotation (11) and immunomagnetic separation (dynal, lake success, ny), following the manufacturer - recommended procedures (14). both genotyping and subgenotyping tools used nested pcr amplification of targeted genes. the primers used for gp60 were 5-ata gtc tcc gct gta ttc-3 and 5-tcc gct gta ttc tca gcc-3 for primary pcr and 5-gga agg aac gat gta tct-3 and 5-gca gag gaa cca gca tc-3 for secondary pcr. the pcr reaction contained 1x perkin - elmer (norwalk, cn) pcr buffer, 3 mm mgcl2, 200 m (each) deoxynucleoside triphosphate, 200 nm of the forward and reverse primers, 5 units of taq polymerase, and 0.52 l of dna template (for primary pcr) or 2 l of primary pcr product (for secondary pcr) in a total 100-l reaction mixture. each pcr reaction was then subjected to 35 cycles of denaturation at 94c for 45 seconds, annealing at 50c for 45 seconds, and extension at 72c for 60 seconds, with an initial denaturation at 95c for 3 minutes and a final extension at 72c for 10 minutes. pcr products were sequenced in both directions on an abi3100 (applied biosystems, foster city, ca) with forward and reverse primers. an additional sequencing primer (5-gag ata tat ctt ggt gcg-3) was used in the sequencing of gp60 pcr products. we aligned the study s gp60 nucleotide sequences with each other and with sequences from the genbank database with gcg software (genetics computing group, madison, wi). a neighbor - joining tree was constructed from the aligned sequences as described (15). thirty - three of the 34 stool samples from outbreak a were amplified by both the cowp and ssu rrna - based nested pcrs. rflp analysis of the pcr products showed that all 33 pcr - positive samples had the c. parvum bovine genotype. thirty - two of the 42 stool samples from outbreak b were also positive by pcr, and all belonged to the c. parvum human genotype. furthermore, in outbreak c, 36 of 44 samples had the c. parvum human genotype, and 8 had the bovine genotype. after further epidemiologic investigations, these eight bovine genotypes, although submitted to the primary diagnostic laboratory at the same time as the human genotypes, were considered contemporary sporadic cases and not part of outbreak c. these patients did not live in the distribution area of the water supply implicated in the outbreak. the patients lived in southern down county, whereas the outbreaks occurred in southern antrim county and northern down county. results of the two genotyping methods were in complete agreement in both detection rates and genotyping result. subgenotype analyses of the gp60 gene showed that of the 30 stool isolates of the c. parvum bovine genotype examined for outbreak a, 25 isolates belonged to a single gp60 subgenotype and 5 isolates belonged to another subgenotype. in contrast, 14 samples of the c. parvum bovine genotype isolated from sporadic cases of human cryptosporidiosis from west ireland, which were unrelated to any of the northern ireland outbreaks, belonged to nine subgenotypes. subgenotype analysis of 31 stool samples from outbreak b showed the presence of only one subgenotype of the c. parvum human genotype. for outbreak c, all 36 c. parvum human genotype stool isolates were identical to the subgenotype involved in outbreak b. in addition, all eight c. parvum bovine genotype stool isolates, which were contemporary with, but not from, the area affected by the outbreak, were identical to the predominant subgenotype in outbreak a. the wastewater sample from the blocked drain implicated as the cause of outbreak c contained oocysts of the same subgenotype as the c. parvum human genotype. of the nine sporadic isolates of the c. parvum human genotype from northwest england, eight belonged to the same subgenotype as the c. parvum human genotype involved in outbreaks b and c (figure). most infected persons each had only one genotype / subgenotype of c. parvum, judged by the rflp profile, the absence of underlying signal in the chromatogram of the sequencing result, and at least five independent pcr analyses of each sample. the ssu rrna technique can detect multiple cryptosporidium parasites in individual samples (16). genetic relationship among cryptosporidium parasites found in three northern ireland outbreaks (outbreaks a, b, and c), sporadic cases in west ireland (s1 to s14) and the northwest of england (s15 to s24), subgenotypes described by strong. (11), and an unpublished sequence (af203016) from the genbank database. the isolates with accession numbers were mostly human and bovine and from the united states with the exception of af164488, af164492, and af164493, which were isolated from humans in zaire, peru, and brazil, respectively, but had been passaged in calves in the united states. : ia, ib, ic, and i d for subgenotypes of the c. parvum human genotype and ii for subgenotypes of the c. parvum bovine genotype (11). results of genotyping analysis support epidemiologic observations that these three drinking - water associated outbreaks of cryptosporidiosis in northern ireland were unrelated, although they all occurred in the greater belfast area over a 1-year period. outbreak a was caused by the c. parvum bovine genotype, and outbreaks b and c were caused by the c. parvum human genotype. the occurrence of the c. parvum human genotype in outbreaks b and c suggests that these two outbreaks were, at least in part, caused by contamination of the drinking - water supply by seepage of raw sewage and through wastewater into the drinking water distribution systems, respectively. the source of contamination is further supported by subgenotyping analysis of the wastewater sample from the blocked drain that was epidemiologically implicated in outbreak c. this sample contained one subgenotype of the c. parvum human genotype indistinguishable from the subgenotype found in most infected persons. the failure to detect cryptosporidium in 10 of the microscopically positive samples in outbreak b was most likely not because of rare cryptosporidium genotypes ; the ssu rrna technique is cryptosporidium genus specific and detects all known cryptosporidium spp. the presence of pcr inhibitors in the extracted dna may have prevented the detection of cryptosporidium by pcr. results of subgenotyping analysis nevertheless indicate that the three recent cryptosporidiosis outbreaks in northern ireland were caused by two predominant subgenotypes of c. parvum that probably had been circulating in the community before the outbreaks. these two subgenotypes of c. parvum are also the most common subgenotypes found in northern ireland and northwest england. the human subgenotype was found in 8 of 9 sporadic isolates from northwest england and the bovine subgenotype in 4 of 14 isolates in another part of ireland. the two subgenotypes of the c. parvum bovine genotype found in outbreak a and concurrent with outbreak c have not been found in most other areas (3,4). the only c. parvum isolate identical to one of the subgenotypes is an unpublished sequence (af2030016) deposited in genbank (figure). in contrast, the subgenotype of the c. parvum human genotype involved in outbreaks b and c has a wide geographic distribution, with isolates from united states, canada, united kingdom, portugal, and peru (3,4). this subgenotype, the most common subgenotype of the c. parvum human genotype found in the united states, was responsible for several waterborne and foodborne outbreaks of human cryptosporidiosis (3). whether the wide distribution of this subgenotype of the c. parvum human genotype and apparent association with multiple outbreaks in geographically distinct areas result from unusual biologic fitness of this parasite is unknown. | three recent drinking - water associated cryptosporidiosis outbreaks in northern ireland were investigated by using genotyping and subgenotyping tools. one cryptosporidium parvum outbreak was caused by the bovine genotype, and two were caused by the human genotype. subgenotyping analyses indicate that two predominant subgenotypes were associated with these outbreaks and had been circulating in the community. |
poker is a card game that was created in the united states in the 1820s (depaulis, 2008). the game became popular in the 1970s with the setting up of the world series of poker. it has become a spectacular craze in our society and there is a strong tendency to gamble (ross & codina, 2009). a french survey revealed that one patient in five from the active file of the excessive gambling reference centre (centre de recherche sur le jeux excessif, crje) of nantes hospital was a poker player, including 75% of online players (venisse & grall - bronnec, 2012). recently, the french game observatory (observatoire du jeu, odj) indicated that 22% of the poker player population has a problematic use, including 14% with an excessive use (eroukmanoff, costes, & tovar, 2014). a comparative study between french and quebec (canada) populations suggested that the level of excessive poker players was 14% in quebec versus 18% in france (kairouz, nadeau, tovar, & pousset, 2014). shead, hodgins, and scharf (2008) found a positive association between the playing online and the score on problem gambling severity index (pgsi) (ferris & wynne, 2001), and poker players had higher scores of problematic use of alcohol (audit). according to the authors best knowledge, only a few international epidemiological data are available to estimate the prevalence of excessive gaming in the poker player population. the expressions pathological gambling, and risky gambling are common and often used interchangeably. pathological gambling means that a pathological gambling diagnosis has been established, based on the criterion of the dsm-5 (american psychiatric association, 2013). pathological and problematic gambling are cross - checked, and we will use one or the other depending on the chosen framework (american or canadian). a tool like the south oaks gambling screen (sogs, lesieur & blume, 1987) is used to diagnose pathological gambling, whereas the pgsi (ferris & wynne, 2001) diagnoses problematic gambling. risky gamblers are identified by obtaining a score between 1 and 4 on the sogs (some problems with gambling) or between 3 and 7 on the pgsi (moderate level of problems leading to some negative consequences). poker is an active game, whose outcome can be influenced by skills. it differs from passive games in which the outcome depends entirely on chance (slot machines, lottery) (bonnaire, lejoyeux, & dardennes, 2004). one of the main reasons for the interest in poker is this major address component (dufour, petit, & brunelle, 2012 ; shead., 2008 ; turner & fritz, 2001 ; wood, griffiths, & parke, 2007). time spent on initiation and learning the codes and practices of the game can be long, requiring significant personal investment compared with other types of gambling (eroukmanoff., 2014). address expertise and experience explain why some players have made poker their main professional activity. professional players are those for whom their main source of income is online poker. in most studies, professionals of online poker. in poker, address and mastery of the game determine the gains over the long term. chance predominates at the level of a hand, but the skills of the player determine whether they will win or lose at the level of 100,000 hands (dedonno & detterman, 2008). a qualitative study indicated that for a poker player, to play their best and to win over the long term, they would need technical skills (mastering the rules of the game and strategies), psychological and emotional skills (self - regulation and specific analysis of opponents) and financial skills (ability to assess the financial risk correctly) (bouju, grall - bronnec, quistrebert - davanne, hardouin, & venisse, 2013). several studies have shown that the problematic use of poker is positively linked to cognitive distortions, external motives to play, and difficulties in identifying feelings (bouju, hardouin,., 2013 ; joukhador, blaszczynski, & maccallum, 2004 ; mitrovic & brown, 2009). recreational players compared with problematic players bet lower daily amounts of money and have fewer anxious disorders (bouju, hardouin,., poker is different from other gambling games in that it has specific game characteristics and the player presents psychopathological and behavioral specificity. however, these studies do not consider whether problematic gambling behaviors are exclusively associated with online poker or if these gamblers participate in any other type of gambling. it enables a larger number of hands to be played and gives access to technical tools (additional software) that can support the skills needed and improve mastery of the game. more than other online players (mmorpg, online games, etc.), poker players consider that internet improves game conditions (eroukmanoff., 2014). the main advantages reported are playing at home, privacy in the playing environment, freedom to smoke, and the opportunity to gain experience quickly compared with traditional media (eroukmanoff., 2014). however, this new environment deprives the player of face - to - face information. behind the screen, communication with other players is limited to verbal communication, reducing the emotional control consequences on the game outcome. in online, the game environment and the poker players behavior change. according to the french regulation authority of online gaming (autorit de rgulation de jeu en ligne, arjel), online gamers are mostly men (88%) and poker players (61%). the french observatory of gambling (odj) indicates that 62% of online poker players consider that their gambling activities have an impact on their lifestyle, leading them to neglect daily tasks in favor of playing the game (22%). nineteen percent of online poker players report that their gambling habit has already been the subject of criticism from relatives (eroukmanoff., 2014). there are special features among gamblers as a function of the most frequently used games (bonnaire, bungener, & varescon, 2009 ; lund, 2011). for example, there is a trend for problematic gambling on internet compared to at the poker table. virtual gamblers have 34 times more risk to be compulsive gamblers than those who play around a table (dufour., 2012 ; kairouz, paradis, & nadeau, 2012 ; wood., 2007). a pilot study on online problematic gambling among students showed that 19% of online gamers were problematic. a negative mood after the game and a general negative mood predicted problematic online gambling (matthews, farnsworth, & griffiths, 2009 ; mccormack, shorter, & griffiths, 2013). these results are contradictory to most studies on gambling. among poker players for example, problematic gamblers are losing or winning players, irrational or rational in their game perception, and their playing styles can be uncontrolled or controlled. it seems that online poker challenges existing theoretical concepts about problem gambling behaviors, especially concerning money spent and lost, rationality, and control abilities (bjerg, 2010). the purpose of this literature review is to provide a state - of - the - art on the knowledge available today about the online poker player population. what is known about the psychopathology of online poker players ? what is the prevalence of problematic online poker ? what are the predictors of problematic online poker ? finally, which research aspect of online poker remains unexplored ? poker is an active game, whose outcome can be influenced by skills. it differs from passive games in which the outcome depends entirely on chance (slot machines, lottery) (bonnaire, lejoyeux, & dardennes, 2004). one of the main reasons for the interest in poker is this major address component (dufour, petit, & brunelle, 2012 ; shead., 2008 ; turner & fritz, 2001 ; wood, griffiths, & parke, 2007). time spent on initiation and learning the codes and practices of the game can be long, requiring significant personal investment compared with other types of gambling (eroukmanoff., 2014). address expertise and experience explain why some players have made poker their main professional activity. professional players are those for whom their main source of income is online poker. in most studies, professionals of online poker. in poker, address and mastery of the game determine the gains over the long term. chance predominates at the level of a hand, but the skills of the player determine whether they will win or lose at the level of 100,000 hands (dedonno & detterman, 2008). a qualitative study indicated that for a poker player, to play their best and to win over the long term, they would need technical skills (mastering the rules of the game and strategies), psychological and emotional skills (self - regulation and specific analysis of opponents) and financial skills (ability to assess the financial risk correctly) (bouju, grall - bronnec, quistrebert - davanne, hardouin, & venisse, 2013). several studies have shown that the problematic use of poker is positively linked to cognitive distortions, external motives to play, and difficulties in identifying feelings (bouju, hardouin,., 2013 ; joukhador, blaszczynski, & maccallum, 2004 ; mitrovic & brown, 2009). recreational players compared with problematic players bet lower daily amounts of money and have fewer anxious disorders (bouju, hardouin,., 2013). poker is different from other gambling games in that it has specific game characteristics and the player presents psychopathological and behavioral specificity. however, these studies do not consider whether problematic gambling behaviors are exclusively associated with online poker or if these gamblers participate in any other type of gambling. it enables a larger number of hands to be played and gives access to technical tools (additional software) that can support the skills needed and improve mastery of the game., poker players consider that internet improves game conditions (eroukmanoff., 2014). the main advantages reported are playing at home, privacy in the playing environment, freedom to smoke, and the opportunity to gain experience quickly compared with traditional media (eroukmanoff., 2014). however, this new environment deprives the player of face - to - face information. behind the screen, communication with other players is limited to verbal communication, reducing the emotional control consequences on the game outcome. in online, the game environment and the poker players behavior change. according to the french regulation authority of online gaming (autorit de rgulation de jeu en ligne, arjel), online gamers are mostly men (88%) and poker players (61%). the french observatory of gambling (odj) indicates that 62% of online poker players consider that their gambling activities have an impact on their lifestyle, leading them to neglect daily tasks in favor of playing the game (22%). nineteen percent of online poker players report that their gambling habit has already been the subject of criticism from relatives (eroukmanoff., 2014). there are special features among gamblers as a function of the most frequently used games (bonnaire, bungener, & varescon, 2009 ; lund, 2011). for example, there is a trend for problematic gambling on internet compared to at the poker table. virtual gamblers have 34 times more risk to be compulsive gamblers than those who play around a table (dufour., 2012 ; kairouz, paradis, & nadeau, 2012 ; wood., 2007). a pilot study on online problematic gambling among students showed that 19% of online gamers were problematic. a negative mood after the game and a general negative mood predicted problematic online gambling (matthews, farnsworth, & griffiths, 2009 ; mccormack, shorter, & griffiths, 2013). for example, problematic gamblers are losing or winning players, irrational or rational in their game perception, and their playing styles can be uncontrolled or controlled. it seems that online poker challenges existing theoretical concepts about problem gambling behaviors, especially concerning money spent and lost, rationality, and control abilities (bjerg, 2010). the purpose of this literature review is to provide a state - of - the - art on the knowledge available today about the online poker player population. what is known about the psychopathology of online poker players ? what is the prevalence of problematic online poker ? what are the predictors of problematic online poker ? finally, which research aspect of online poker remains unexplored ? several methods were employed to ensure that the search for pertinent studies was all - encompassing. articles included were published in english, in a peer - review journal (excluding books, theses, and dissertations) after 2000 (before this date, few households had access to computers and internet). first, a search was undertaken on pubmed and psychinfo via ebsco and on sciencedirect, using all articles including poker in the title or key words were selected.step 2 : reading abstracts and references. articles focusing on poker web sites, advertising, the legal framework, an analysis of poker games, or gaming operator data were excluded.step 3 : reading articles. after reading the above articles, we selected those that met the following criteria : qualitative and quantitative methodology, population including at least one sample of online poker players, considering psychopathological variables (excessive gambling, personality, anxiety, depression) or tilt. first, a search was undertaken on pubmed and psychinfo via ebsco and on sciencedirect, using articles focusing on poker web sites, advertising, the legal framework, an analysis of poker games, or gaming operator data were excluded. step 3 : reading articles. after reading the above articles, we selected those that met the following criteria : qualitative and quantitative methodology, population including at least one sample of online poker players, considering psychopathological variables (excessive gambling, personality, anxiety, depression) or tilt. selection of articles articles focusing exclusively on professional players or with variables centered exclusively on decision - making or skills were excluded. in fact, decision - making and professional poker players behavior are complex issues. these topics differ from the issue of the psychopathology of the overall population of players and deserve a specific study. four research teams wrote 13 of these articles (wood and griffiths [2 articles ], barrault and varescon [3 articles ], hopley and nicki [3 articles ], and palomki and laakasuo [5 articles ]). most of the samples were composed of young men (between 74% and 100%). for all studies except that of gainsbury, suhonen, and saastamoinen (2014) (in which 60% were older than 35), the participants average age ranged between 21 and 30 years (table 1). generally, the scales used in these studies are very heterogeneous and may not be validated (see table 1). four main tools were used : the pgsi (4 articles), the sogs (3 articles), dsm - iv - tr criteria (3 articles), and the behavioral addiction scale (based on griffiths, 2005, 1 article). these four tools do not have the same sensitivity and make results difficult to compare (venisse & grall - bronnec, 2012). furthermore, most of the samples were not the representative of the poker player population, as they included professional players or a limited number of online poker players. the first study in this area was conducted by wood. their findings indicated that the main predictors of problematic use were changing the gender of their avatar (male having a female avatar) (= 0.27, p < 0.001), negative mood states after playing (guilty) (= 0.12, p < 0.002), and playing to escape from problems (= 0.17, p < 0.001). a second study performed with the same data set was published by griffiths, parke, wood, and rigbye (2009) and investigated the predictors of financial success in online poker. the financial gains were positively linked to discipline avoidance of spending over their monthly gambling budget (= 0.23, p < 0.0001), playing at a higher stake level (= 0.191, p < 0.0001), not overestimating the skills involved in poker (= 0.115, p < 0.0001) and perceiving themselves as more skilful (= 0.111, p < 0.05). (2009) found no relationship between the time spent and the score of pathological gambling factors when measured with the dsm - iv diagnostic for pathological gambling. the conclusions of these two studies indicated that the student population was particularly at risk of developing problematic gambling behavior. these conclusions need to be nuanced as the authors did not consider the specific case of professional poker players. hopley and nicki (2010) and hopley, dempsey, and nicki (2012) replicated and extended the findings of these two previous studies (griffiths. was predicted by time played (= 0.62, p < 0.001), internal locus of control (= 0.44, p = 0.005), dissociation (= 0.33, p < 0.001), impulsivity (= 0.21, p < 0.01), boredom proneness (= 0.14, p < 0.05), and the negative emotion of stress (= 0.15, p < 0.05). these two models explained 42% (hopley & nicki, 2010) and 67% (hopley., 2012) of the pgsi score variance. in these two studies, most of the participants were experienced players. in the 2010 article, 19% of players made a living by playing poker, whereas in the 2012 research, the average weekly playing time was 16 h among a small sample of 62 participants. the results indicated that the main predictors were dissociated, and the internal locus of control inducing increased irrational beliefs. the link between internal locus of control and irrational beliefs should be clarified by considering poker skills and the sample s high level of expertise. (2012) and hopley and nicki (2010) found a positive correlation between the time spent playing and the pathological gaming score when measured with the pgsi. the authors suggested that in the population of online poker players, playing time is a poor indicator of problematic gambling due to experienced and/or professional players. in poker, skills are part of the game, and impact the score obtained on the pgsi, particularly due to chasing included in the questionnaire. chasing could be a different process when experienced by professional players (going back to work) or problematic gamblers. these studies are the first to raise the problem of the measurement of problematic gambling in professional or very experienced populations (hopley & nicki, 2010). a third study published in 2014 focused on the link between workaholism and problematic gambling in a population of experienced online poker players (hopley, wagner, & nicki, 2014). this last research complemented the previous work, evidencing that for experienced players, poker is either an additional income or a professional activity. problematic online poker and workaholism share common predictors (stress, neuroticism, and internal locus of control) (hopley & nicki, 2010). contrary to the authors hypothesis, no significant link was found between problematic gambling and workaholism. problematic gambling was predicted by an external locus of control (r = 0.71, p < 0.05) and by stress (r = 0.78, p < 0.05). among the 31 highly experienced participants, this very high proportion confirms the inability of the pgsi to measure problematic gambling among experienced online players. however, workaholism is not an alternative to identify problematic gambling in online poker players. barrault and varescon (2013a, 2013b) worked on the factors predicting online poker pathological gambling. (= 0.26 ; p < 0.001) and illusion of control (= 0.20, p < 0.001), and anxiety (= 0.15, p = 0.01) were good predictors of sogs scores among poker players (barrault & varescon, 2013a). for these authors, the illusion of control plays an important role in the development of pathological gambling in a game of skill such as online poker. however, assessing gambling irrational belief in a game of skill raises the question of the validity of the measure of this scale in the poker player population. both have been identified as problematic gambling risk factors (demaree, dedonno, burns, & everhart, 2008 ; petry, 2001). the authors assessed the specific connection between online poker and impulsivity (barrault & varescon, 2013b). their results indicated that all online poker players had a higher level of sensation seeking, regardless of their intensity of gambling. the model including frequency and duration of game session, impulsivity, and sensation seeking explained 12% of sogs variance. impulsivity was strongly predictive of the pathological use of online poker (= 0.32, p < 0.001), but sensation seeking was not a significant predictor. these studies were carried out with the sogs, which is based on the dsm - iii - r criteria and is increasingly used less than the pgsi. although the dichotomous quotation makes sogs, a more appropriate tool for clinical practice, it is relatively not discriminative in the overall population (false positive) (stinchfield, 2002)., several comparative studies have been conducted to improve the understanding of influence that skills and experience have on poker player behavior and problematic gambling. one study focused on the psychopathological differences between recreational online poker players (rpp) and professional online poker players (ppp) (biolcati, passini, & griffiths, 2014). the comparison showed that ppps spend more time for playing poker, wager more money, open more tables, and have longer gaming sessions than rpps. (2014) showed that narcissism (= 0.14, p < 0.05), impulsivity (= 0.18, p < 0.01) and the motives of excitement (= 0.17, p < 0.01), and escape from reality 0.05) were positively associated with the dsm - iv - tr criteria of pathological gambling. furthermore, self - esteem (= 0.19 ; p < 0.001) was negatively associated with problem gambling criteria. in this study, the proportion of pathological players was the lowest (1.6%) due to the large number of professional players (50% of the sample). furthermore, 46% of the ppps and 42.9% of the rpps declared that they felt chasing (no significant difference). however, gambling to recover lost bets, in a game including skills such as poker, does not have the same meaning as in a game of chance. for professional players, the concept of chasing should be regarded more carefully as a problematic gambling criterion for online poker. (2014) studied chasing in a population of online poker and casino gamblers. chasing losses is one of the diagnostic criteria of problematic gambling and one of the rare observable behaviors of problematic gambling (gainsbury, 2011). the international sample of this study was composed of 10,838 online gamblers, including 5,461 poker players, recruited in 2006. the poker player sample was mostly composed of men aged over 35 years (61%). in most studies, the age of this population ranged between 18 and 30 years. the results indicated that the risk of chasing decreased with age (1.5%), corroborating the conclusions of griffiths. irrational beliefs (hot hand and gambler fallacy) (17.6% and 39%), more money spent (1.7%), female gender (11.7%), being mainly a cash player (3.8%), and excitement and winning money motives (3.1% and 2.2%) increased the risk of chasing. the skill level (1.9%) and playing for relaxation (1.4%) decreased the risk of chasing. there was no significant link between the duration and the frequency of the game and chasing. playing experienced poker players proved more disciplined and less sensitive to irrational beliefs and consequently to chasing. in this study, the frequency of chasing if you lose when gambling online, are you more likely or less likely to keep playing to try and win some money back ? less likely ; more likely ; i would be unaffected by what was lost on previous gambles. this evaluation raises the question of the gambler s awareness of their own chasing behavior. two studies focused on the influence of the gamblers experience on gambling behavior (laakasuo. poker skills have both a technical (game strategy - related) and an emotional (emotion regulation - related) aspect. in the first study (palomki., 2013a) the results pointed out cognitive decision - making processes specific to inexperienced and experienced players. poker experience was linked to more self - reflection (philosophical and detached analysis of situations, decisions, and emotions) and inexperience to self - rumination (going over the negative experience, inability to let it go) after a correct answer. (2014b) showed that a predisposition for emotional stability was linked to higher levels of poker experience. first, emotional stability was assessed using the emotionality factor from the hexaco, similar to the emotional aspect of the big five personality inventory (ashton & lee, 2007, 2009 ; lee & ashton, 2004). this emotionality factor is a personality trait and could not be considered as emotional regulation ability. second, most of the correlations between the emotionality factor, the total score, and the items of the poker experience scale (pes) were significant but not powerful (< 0.25). in these studies, the authors did not measure problematic gambling, and the pes used to measure poker experience was not validated. however, more needs to be known about its convergent validity, factorial structure, and psychometric reliability. the publication of the validation studies would enable this tool to be more precise and clear about validity, accuracy, and internal / external consistency. (2012, 2014) and hopley and nicki (2010), concerning the validity of the scales used to assess problematic gambling among experienced poker players (laakasuo, palomki, & salmela, 2015). this article, divided into three studies, extended the results of the previous study by questioning the validity of the pgsi and sogs in the population of experienced online poker players (laakasuo., 2015). these studies were undertaken using three different samples, two of which had been used in other articles (see table 1). the authors used amended versions of the pgsi and sogs, the pes, and scales assessing satisfaction in life, well - being, emotion regulation, and social adaptation (see table 1). in the first study (n = 478), a negative correlation was found between the pgsi and the satisfaction in life (r = 0.15, p < 0.001), empathizing abilities (emotional intelligence) (r = 0.22, p < 0.001), and poker experience (r = 0.20, p < 0.001). however, poker experience was not correlated with satisfaction in life (r = 0.02, ns) or empathizing abilities (r = 0.03, ns). in the second study (n = 417), the results showed a correlation between the sogs and the pes (r = 0.29, p < 0.001). in the third study (n = 354), there was no correlation between pes and social well - being (r = 0.01, ns), anomia (r = 0.04, ns), marginalization of society alienation (r = 0.01, ns), self - control (r = 0.02, ns), and emotional intelligence (r = 0.03, ns). problematic gambling scales (sogs or pgsi) were negatively related to well - being, emotion regulation, and social adaptation. experienced players had higher scores on the pgsi or sogs but did not suffer from trouble in social adaptation, emotion regulation, or well - being. (2015) hypothesized that this contradictory link could be due to the skills required to play poker. in poker, if the player wants to acquire experience and skills, he needs to practice and to spend time and money. with experience, consequently, players could meet several criteria for problematic gambling and increase the rate of problematic gamblers. the authors concluded that the sogs and pgsi are not appropriate for measuring problematic gambling in the population of experienced poker players. to our knowledge, this study is the first to explore the question of the validity of the measure of problematic gambling among experienced players. the authors primarily used a modified version of the pgsi and sogs and rated experiences on a likert scale rather than on a dichotomous one. modifying the measure used in a validated scale (e.g., changing a dichotomous to a likert scale) this does not mean that the measure is invalid but, even though the discriminant and convergent validity is maintained, it is difficult to interpret the scores obtained. thus, they can not be compared to previous data or the cut - off used. on the other hand, the authors drew general conclusions by combining the results of the three studies using three different protocols. a study on a unique and representative sample to compare the psychopathological and adaptive characteristics of experienced and novice online poker players should be implemented. finally, it is not known if experienced players represent a major or a minor proportion of the online poker player population. last, two inconsistent studies focused on the comparison of the psychopathological characteristics between online and offline poker players. the findings of szab and kocsis (2012) suggested that traditional players were more problematic than online players. in fact, their sample of traditional players was small (35 players) and unrepresentative of the whole poker player population (mean age 32.9 [sd = 10.8 ], with 26% women). mihaylova, kairouz, and nadeau (2013) found a significantly higher proportion of problem gamblers online than offline (17.6% and 1.1%, respectively). in addition, online poker players were more likely to have consumed illicit drugs during the past year, particularly cocaine. compared with the population of poker players, this sample included many women (40% of the table players). substance use was measured using frequency scales instead of validated scales to assess substance use disorders (e.g., audit, cudit, or mini). the psychopathological differences between online and offline populations remain to be explored. raised by griffiths. (2009), poker tilt has been explored in three studies (barrault, untas, & varescon, 2014 ; palomki, laakasuo, & salmela, 2013b, 2014). two of these were qualitative (barrault., 2014 ; palomki., 2013b). tilting is defined as a strong negative emotional state elicited by elements of the poker game (e.g., bad beats or a prolonged losing streak) that is characterised by losing control, and due to which the quality of decision - making in poker has decreased one of the main articles on this topic concerns traditional poker and dates from 25 years ago (browne, 1989). in a qualitative study, including 56 participants using an internet data collection, the authors asked participants to write their story about a situation concerning a significant loss of money while playing online poker (palomki., 2013b). after a significant loss, tilt occurs in three phases : (1) a dissociative phase (disbelief, unreality, unwillingness to accept the events), (2) a phase of indignation and negative emotions (feelings of injustice and unfairness), (3) and the chasing phase. as an outcome, tilt produces disappointment in oneself for losing control, guilt, and anxiety and depression feelings. finally, over the long term, it induces ruminations, sleep disturbances, and negative mood. however, a significant loss could lead to different pathways as a function of attribution of loss to a bad beat (unlucky) or a bad play (made a mistake). inexperienced players reported a bad beat and experienced players a bad play attribution. exhaustion or needling by other players could also lead to tilt on minor losses (browne, 1989). a quantitative correlation study aimed to identify the factors influencing the perceived severity of tilting. the authors created a four - item scale measuring the severity of tilting (palomki., 2014). they proposed a model linking poker experience (pe), perceived effect of experience on tilting (peet), sensitivity to losses, and severity of tilting. their results indicated that poker experience was associated with more intense, frequent tilt perceived as severe. however, experience at poker was also associated with perceiving experience as an attribute to tilt less severely. the interaction between pe and peet indicated a protective effect of a high peet score on tilt severity for the experienced players, who could have a better perception of the severity of their tilt. then, sensitivity to losses (experience of negative emotions associated with losses, e.g., unfairness, anger, and frustration) was the main and strongest predictor of tilting severity. a moderate mediation effect suggested that peet regulated sensitivity to losses among experienced poker players. experience in the game and in tilting through emotion regulation plays a role in decision - making processes during poker playing, especially when players experience losses. assessing pathological gambling the latter should experience more severe tilt and act in a different pattern concerning emotion regulation and decision - making than normal players. finally, for most of the questionnaires, the validations have not yet been published (e.g., questionnaires of peet, sensitivity to losses and severity of tilting), raising questions about the validity and accuracy of the measure. tilt was the most mentioned item (29% of the corpus referred to it). this item included two classes, the first centered on emotional experience and the second on player behavior during tilt. all the players interviewed indicated having experienced tilt while the most reported strategy to cope with it was to stop playing. players in this sample had different levels of experience (but at least 1 year of poker playing), and problematic gaming was not assessed. did experienced and novice players have similar representations ? how did experienced players learn to cope with tilt episodes ? were novice players able to identify tilt episodes and cope with them ? their findings indicated that the main predictors of problematic use were changing the gender of their avatar (male having a female avatar) (= 0.27, p < 0.001), negative mood states after playing (guilty) (= 0.12, p < 0.002), and playing to escape from problems (= 0.17, p < 0.001). a second study performed with the same data set was published by griffiths, parke, wood, and rigbye (2009) and investigated the predictors of financial success in online poker. the financial gains were positively linked to discipline avoidance of spending over their monthly gambling budget (= 0.23, p < 0.0001), playing at a higher stake level (= 0.191, p < 0.0001), not overestimating the skills involved in poker (= 0.115, p < 0.0001) and perceiving themselves as more skilful (= 0.111, p < 0.05). success was related to specific skills. (2009) found no relationship between the time spent and the score of pathological gambling factors when measured with the dsm - iv diagnostic for pathological gambling. the conclusions of these two studies indicated that the student population was particularly at risk of developing problematic gambling behavior. these conclusions need to be nuanced as the authors did not consider the specific case of professional poker players. hopley and nicki (2010) and hopley, dempsey, and nicki (2012) replicated and extended the findings of these two previous studies (griffiths. 2007) using questionnaires validated psychometrically. in their studies, problematic gambling (measured with the pgsi) was predicted by time played (= 0.62, p < 0.001), internal locus of control (= 0.44, p = 0.005), dissociation (= 0.33, p < 0.001), impulsivity (= 0.21, p < 0.01), boredom proneness (= 0.14, p < 0.05), and the negative emotion of stress (= 0.15, p < 0.05). these two models explained 42% (hopley & nicki, 2010) and 67% (hopley., 2012) of the pgsi score variance. in these two studies, most of the participants were experienced players. in the 2010 article, 19% of players made a living by playing poker, whereas in the 2012 research, the average weekly playing time was 16 h among a small sample of 62 participants. the results indicated that the main predictors were dissociated, and the internal locus of control inducing increased irrational beliefs. the link between internal locus of control and irrational beliefs should be clarified by considering poker skills and the sample s high level of expertise. (2012) and hopley and nicki (2010) found a positive correlation between the time spent playing and the pathological gaming score when measured with the pgsi. the authors suggested that in the population of online poker players, playing time is a poor indicator of problematic gambling due to experienced and/or professional players. in poker, skills are part of the game, and impact the score obtained on the pgsi, particularly due to chasing included in the questionnaire. chasing could be a different process when experienced by professional players (going back to work) or problematic gamblers. these studies are the first to raise the problem of the measurement of problematic gambling in professional or very experienced populations (hopley & nicki, 2010). a third study published in 2014 focused on the link between workaholism and problematic gambling in a population of experienced online poker players (hopley, wagner, & nicki, 2014). this last research complemented the previous work, evidencing that for experienced players, poker is either an additional income or a professional activity. problematic online poker and workaholism share common predictors (stress, neuroticism, and internal locus of control) (hopley & nicki, 2010). contrary to the authors hypothesis, no significant link was found between problematic gambling and workaholism. problematic gambling was predicted by an external locus of control (r = 0.71, p < 0.05) and by stress (r = 0.78, p < 0.05). among the 31 highly experienced participants, this very high proportion confirms the inability of the pgsi to measure problematic gambling among experienced online players. however, workaholism is not an alternative to identify problematic gambling in online poker players. barrault and varescon (2013a, 2013b) worked on the factors predicting online poker pathological gambling. (= 0.26 ; p < 0.001) and illusion of control (= 0.23, p < 0.001), depression (= 0.20, p < 0.001), and anxiety (= 0.15, p = 0.01) were good predictors of sogs scores among poker players (barrault & varescon, 2013a). for these authors, the illusion of control plays an important role in the development of pathological gambling in a game of skill such as online poker. however, assessing gambling irrational belief in a game of skill raises the question of the validity of the measure of this scale in the poker player population. both have been identified as problematic gambling risk factors (demaree, dedonno, burns, & everhart, 2008 ; petry, 2001). the authors assessed the specific connection between online poker and impulsivity (barrault & varescon, 2013b). their results indicated that all online poker players had a higher level of sensation seeking, regardless of their intensity of gambling. the model including frequency and duration of game session, impulsivity, and sensation seeking explained 12% of sogs variance. impulsivity was strongly predictive of the pathological use of online poker (= 0.32, p < 0.001), but sensation seeking was not a significant predictor. these studies were carried out with the sogs, which is based on the dsm - iii - r criteria and is increasingly used less than the pgsi. although the dichotomous quotation makes sogs, a more appropriate tool for clinical practice, it is relatively not discriminative in the overall population (false positive) (stinchfield, 2002)., several comparative studies have been conducted to improve the understanding of influence that skills and experience have on poker player behavior and problematic gambling. one study focused on the psychopathological differences between recreational online poker players (rpp) and professional online poker players (ppp) (biolcati, passini, & griffiths, 2014). the comparison showed that ppps spend more time for playing poker, wager more money, open more tables, and have longer gaming sessions than rpps. (2014) showed that narcissism (= 0.14, p < 0.05), impulsivity (= 0.18, p < 0.01) and the motives of excitement (= 0.17, p < 0.01), and escape from reality 0.05) were positively associated with the dsm - iv - tr criteria of pathological gambling. furthermore, self - esteem (= 0.19 ; p < 0.001) was negatively associated with problem gambling criteria. in this study, the proportion of pathological players was the lowest (1.6%) due to the large number of professional players (50% of the sample). furthermore, 46% of the ppps and 42.9% of the rpps declared that they felt chasing (no significant difference). however, gambling to recover lost bets, in a game including skills such as poker, does not have the same meaning as in a game of chance. for professional players, the concept of chasing should be regarded more carefully as a problematic gambling criterion for online poker. (2014) studied chasing in a population of online poker and casino gamblers. chasing losses is one of the diagnostic criteria of problematic gambling and one of the rare observable behaviors of problematic gambling (gainsbury, 2011). the international sample of this study was composed of 10,838 online gamblers, including 5,461 poker players, recruited in 2006. the poker player sample was mostly composed of men aged over 35 years (61%). in most studies, the results indicated that the risk of chasing decreased with age (1.5%), corroborating the conclusions of griffiths. irrational beliefs (hot hand and gambler fallacy) (17.6% and 39%), more money spent (1.7%), female gender (11.7%), being mainly a cash player (3.8%), and excitement and winning money motives (3.1% and 2.2%) increased the risk of chasing. the skill level (1.9%) and playing for relaxation (1.4%) decreased the risk of chasing. there was no significant link between the duration and the frequency of the game and chasing. playing experienced poker players proved more disciplined and less sensitive to irrational beliefs and consequently to chasing. in this study, the frequency of chasing was measured using a question with three possible answers : if you lose when gambling online, are you more likely or less likely to keep playing to try and win some money back ? less likely ; more likely ; i would be unaffected by what was lost on previous gambles. this evaluation raises the question of the gambler s awareness of their own chasing behavior. two studies focused on the influence of the gamblers experience on gambling behavior (laakasuo., 2014b ; palomki, laakasuo, & salmela, 2013a). poker skills have both a technical (game strategy - related) and an emotional (emotion regulation - related) aspect. in the first study (palomki., 2013a) the results pointed out cognitive decision - making processes specific to inexperienced and experienced players. poker experience was linked to more self - reflection (philosophical and detached analysis of situations, decisions, and emotions) and inexperience to self - rumination (going over the negative experience, inability to let it go) after a correct answer. (2014b) showed that a predisposition for emotional stability was linked to higher levels of poker experience. first, emotional stability was assessed using the emotionality factor from the hexaco, similar to the emotional aspect of the big five personality inventory (ashton & lee, 2007, 2009 ; lee & ashton, 2004). this emotionality factor is a personality trait and could not be considered as emotional regulation ability. second, most of the correlations between the emotionality factor, the total score, and the items of the poker experience scale (pes) were significant but not powerful (< 0.25). in these studies, the authors did not measure problematic gambling, and the pes used to measure poker experience was not validated. however, more needs to be known about its convergent validity, factorial structure, and psychometric reliability. the publication of the validation studies would enable this tool to be more precise and clear about validity, accuracy, and internal / external consistency. (2012, 2014) and hopley and nicki (2010), concerning the validity of the scales used to assess problematic gambling among experienced poker players (laakasuo, palomki, & salmela, 2015). this article, divided into three studies, extended the results of the previous study by questioning the validity of the pgsi and sogs in the population of experienced online poker players (laakasuo., 2015). these studies were undertaken using three different samples, two of which had been used in other articles (see table 1). the authors used amended versions of the pgsi and sogs, the pes, and scales assessing satisfaction in life, well - being, emotion regulation, and social adaptation (see table 1). in the first study (n = 478), a negative correlation was found between the pgsi and the satisfaction in life (r = 0.15, p < 0.001), empathizing abilities (emotional intelligence) (r = 0.22, p < 0.001), and poker experience (r = 0.20, p < 0.001). however, poker experience was not correlated with satisfaction in life (r = 0.02, ns) or empathizing abilities (r = 0.03, ns). in the second study (n = 417), the results showed a correlation between the sogs and the pes (r = 0.29, p < 0.001). in the third study (n = 354), there was no correlation between pes and social well - being (r = 0.01, ns), anomia (r = 0.04, ns), marginalization of society alienation (r = 0.01, ns), self - control (r = 0.02, ns), and emotional intelligence (r = 0.03, ns). problematic gambling scales (sogs or pgsi) were negatively related to well - being, emotion regulation, and social adaptation. experienced players had higher scores on the pgsi or sogs but did not suffer from trouble in social adaptation, emotion regulation, or well - being. (2015) hypothesized that this contradictory link could be due to the skills required to play poker. in poker, if the player wants to acquire experience and skills, he needs to practice and to spend time and money. with experience, consequently, players could meet several criteria for problematic gambling and increase the rate of problematic gamblers. the authors concluded that the sogs and pgsi are not appropriate for measuring problematic gambling in the population of experienced poker players. to our knowledge, this study is the first to explore the question of the validity of the measure of problematic gambling among experienced players. the authors primarily used a modified version of the pgsi and sogs and rated experiences on a likert scale rather than on a dichotomous one. modifying the measure used in a validated scale (e.g., changing a dichotomous to a likert scale) this does not mean that the measure is invalid but, even though the discriminant and convergent validity is maintained, it is difficult to interpret the scores obtained. thus, they can not be compared to previous data or the cut - off used. on the other hand, the authors drew general conclusions by combining the results of the three studies using three different protocols. a study on a unique and representative sample to compare the psychopathological and adaptive characteristics of experienced and novice online poker players should be implemented. finally, it is not known if experienced players represent a major or a minor proportion of the online poker player population. last, two inconsistent studies focused on the comparison of the psychopathological characteristics between online and offline poker players. the findings of szab and kocsis (2012) suggested that traditional players were more problematic than online players. in fact, their sample of traditional players was small (35 players) and unrepresentative of the whole poker player population (mean age 32.9 [sd = 10.8 ], with 26% women). mihaylova, kairouz, and nadeau (2013) found a significantly higher proportion of problem gamblers online than offline (17.6% and 1.1%, respectively). in addition, online poker players were more likely to have consumed illicit drugs during the past year, particularly cocaine. compared with the population of poker players, this sample included many women (40% of the table players). substance use was measured using frequency scales instead of validated scales to assess substance use disorders (e.g., audit, cudit, or mini). (2009), poker tilt has been explored in three studies (barrault, untas, & varescon, 2014 ; palomki, laakasuo, & salmela, 2013b, 2014). two of these were qualitative (barrault., 2014 ; palomki., 2013b). tilting is defined as a strong negative emotional state elicited by elements of the poker game (e.g., bad beats or a prolonged losing streak) that is characterised by losing control, and due to which the quality of decision - making in poker has decreased one of the main articles on this topic concerns traditional poker and dates from 25 years ago (browne, 1989). in a qualitative study, including 56 participants using an internet data collection, the authors asked participants to write their story about a situation concerning a significant loss of money while playing online poker (palomki. after a significant loss, tilt occurs in three phases : (1) a dissociative phase (disbelief, unreality, unwillingness to accept the events), (2) a phase of indignation and negative emotions (feelings of injustice and unfairness), (3) and the chasing phase. as an outcome, tilt produces disappointment in oneself for losing control, guilt, and anxiety and depression feelings. finally, over the long term, it induces ruminations, sleep disturbances, and negative mood however, a significant loss could lead to different pathways as a function of attribution of loss to a bad beat (unlucky) or a bad play (made a mistake). inexperienced players reported a bad beat and experienced players a bad play attribution. only emotional reactions comprising feelings of injustice and unfairness were linked to tilting. however, the authors limited their findings. exhaustion or needling by other players could also lead to tilt on minor losses (browne, 1989). a quantitative correlation study aimed to identify the factors influencing the perceived severity of tilting. the authors created a four - item scale measuring the severity of tilting (palomki., 2014). they proposed a model linking poker experience (pe), perceived effect of experience on tilting (peet), sensitivity to losses, and severity of tilting. their results indicated that poker experience was associated with more intense, frequent tilt perceived as severe. however, experience at poker was also associated with perceiving experience as an attribute to tilt less severely. the interaction between pe and peet indicated a protective effect of a high peet score on tilt severity for the experienced players, who could have a better perception of the severity of their tilt. then, sensitivity to losses (experience of negative emotions associated with losses, e.g., unfairness, anger, and frustration) was the main and strongest predictor of tilting severity. a moderate mediation effect suggested that peet regulated sensitivity to losses among experienced poker players. experience in the game and in tilting through emotion regulation plays a role in decision - making processes during poker playing, especially when players experience losses. assessing pathological gambling the latter should experience more severe tilt and act in a different pattern concerning emotion regulation and decision - making than normal players. finally, for most of the questionnaires, the validations have not yet been published (e.g., questionnaires of peet, sensitivity to losses and severity of tilting), raising questions about the validity and accuracy of the measure. tilt was the most mentioned item (29% of the corpus referred to it). this item included two classes, the first centered on emotional experience and the second on player behavior during tilt. all the players interviewed indicated having experienced tilt while the most reported strategy to cope with it was to stop playing. players in this sample had different levels of experience (but at least 1 year of poker playing), and problematic gaming was not assessed. did experienced and novice players have similar representations ? how did experienced players learn to cope with tilt episodes ? were novice players able to identify tilt episodes and cope with them ? this literature review identified 17 articles on the psychopathology of online poker players and enabled us to establish a preliminary state of the art of the knowledge in this specific research area. the main conclusions are that several factors predict problematic poker gambling, such as stress, internal attribution, dissociation, boredom tendency, negative emotions, irrational beliefs, anxiety, and impulsivity (barrault & varescon, 2013b ; biolcati., 2014 ; some studies presented inconsistent results, as in the case of the research on the locus of control (hopley & nicki, 2010 ; hopley., 2014). young players are more at risk of chasing and problematic gambling (gainsbury., 2014 ; griffiths., 2009 ; wood., 2007), and the amount of playing time does not appear to be a reliable indicator of a gambling disorder (gainsbury., 2014 ; hopley & nicki, 2010 ; hopley., 2012, 2014). online poker gamblers seem to be younger and to spend more time playing than table players. there is not much information on the psychopathological differences between online and offline poker players, but it seems that the context has an influence on player behavior (mihaylova., 2013 ; szab & kocsis, 2012). this information is consistent with the fact that experienced players (older and playing more hours) are a specific group less at risk of developing pathological or problematic gambling. several studies explored this hypothesis (biolcati., 2014 ; gainsbury., 2014 ; griffiths., 2009 ; laakasuo., 2014b, 2015 ; palomki., 2014 the special features of poker compared to other gambling are skills and their influence on the course of the game. first, from a legislative perspective, if skills are predominant over chance, poker may be classified as a sport., cognitive distortions strongly predict the problematic use of poker (barrault & varescon, 2013a ; gainsbury., 2014). consequently, if there is a real control over the game, is it cognitive distortions ? several recent studies state that being a good player means having greater self - control and adaptive coping and emotion regulation, which may be a protective factor against problematic gambling (biolcati., 2014 ; gainsbury., 2014 ; laakasuo., 2014b, 2015 ; palomki., 2014). nonetheless, the proportion of experienced players in the population of online poker players remains unknown. is experience a protective factor ? or do the common characteristics among players (e.g., intelligence, coping abilities, emotion regulation, and impulsivity) enable them to become experienced players ? one quantitative study focused on players with a low level of expertise compared with experienced players (laakasuo., 2014b) and found differences in emotion regulation between the two groups. to date, no study has examined novice players and their psychopathological variables like impulsivity, anxiety, depression, or personality disorders (e.g., borderline). the variable proportion of problematic players could be an outcome of the bias due to the choice of the tools to measure problematic / pathological online poker. problematic or pathological uses of online poker were assessed with four different tools : dsm - iv - tr criteria (american psychiatric association, 2003), the behavioral addiction scale (griffiths, 2005), the sogs (lesieur & blume, 1987), or the pgsi (ferris & wynne, 2001). experienced players in the samples could explain the high rates of pathological or problematic gambling identified in the studies. (2015) indicated that these tools induced false positives in the experienced player population. almost all tools focusing on problematic gambling integrate chasing, which is considered a behavioral indicator of problematic gambling (american psychiatric association, 2003 ; gainsbury, 2011). however, is it pertinent to regard playing to compensate money losses as chasing when poker playing is a professional activity ? several studies questioned the validity of this criterion among poker players (biolcati., 2014 ; gainsbury., 2014 ; hopley & nicki, 2010 ; hopley., similarly, is it valid to assimilate thoughts such as relating my winnings to my skill and ability makes me continue gambling (gambling - related cognitions scale of raylu & oei, 2004) to irrational beliefs ? these various points demonstrate that existing tools are not fully adequate and difficult to adapt to the online poker playing population. this is a dissociative state induced by frustration leading to a loss of self - control and money. to date, three articles have focused on this phenomenon, from a phenomenological to an etiological perspective. tilt is an abrupt decline in poker skills leading to a loss of money, negative feelings, and chasing. it is a word commonly used by players in online discussion forums and in resources on poker (laakasuo. to become an experienced and winning online poker player, the novice will experience tilt and learn how to manage it (laakasuo. tilt shares some features with problematic gambling behavior, as players experience loss of control, negative feelings, and chasing (browne, 1989). more research is needed to explore the links between problematic online poker, skills, self - control, and tilt. finally, this process brings up the topic of the regulation of emotion in poker, which is a specific and interesting example. methodologically, the studies included were qualitative and quantitative, and the authors used various tools. as it is difficult to compare their results, they must be interpreted cautiously. some tools and concepts furthermore, the range of the study sample sizes must be acknowledged and considered a limitation when comparing the data and the results with each other. more studies are needed in the field of online poker gaming to validate the methodologies and the different concepts (such as tilt) to improve our knowledge. these poker gamblers are part of a closed community and are characterized by a strong impulsiveness, which makes it difficult for them to participate in a research project, especially if this is considered a waste of time. we do not really have information about the players who were willing to contribute to such studies. are these gamblers representative of the whole population of online poker gamblers or does this type of recruitment induce a significant bias ? first, it is necessary to replicate these works in future research in order to consolidate the current data. the use of validated tools and the contribution of data using the same tool (e.g., the pgsindex) should enable a comparison of poker player populations according to their countries and the associated legislation. a specific tool for online poker players should be created and evaluated in order to enable an in - depth study of the characteristics of online poker players. the properties of psychometric tools, particularly regarding excessive gambling and irrational beliefs, should be adapted to poker in order to answer the questions raised by several studies. moreover, few studies have focused on the influence of experience in the game on player psychopathology (laakasuo., 2015 ; palomki., further studies would help understand the influence of experience on emotion and cognition regulation (laakasuo, palomki, & salmela, 2014a). their place in the development of a problematic use of online poker is still little documented in the literature thus more research appears if necessary. finally, the phenomenon of tilt and, more generally, the processes of emotion regulation in online poker deserve to be explored. they could be the targets of prevention and provide a better understanding of the processes involved in online poker gambling. to conclude, the first aim was to explain the problematic use of online poker from a psychopathological perspective. this is a relatively new research area and thus further detailed studies will be required. future research should focus on a crossed perspective, mixing the skills, self - regulation, and psychopathology of online poker players. am designed the study and wrote the protocol, collecting data and conducted the statistical analysis, and drafted the first version of the manuscript. | background and aimsonline texas holdem poker has become a spectacular form of entertainment in our society, and the number of people who use this form of gambling is increasing. it seems that online poker activity challenges existing theoretical concepts about problem gambling behaviors. the purpose of this literature review is to provide a current overview about the population of online poker players.methodsto be selected, articles had to focus on psychopathology in a sample of online poker players, be written in english or french, and be published before november 2015. a total of 17 relevant studies were identified.resultsin this population, the proportion of problematic gamblers was higher than in other forms of gambling. several factors predicting excessive gambling were identified such as stress, internal attribution, dissociation, boredom, negative emotions, irrational beliefs, anxiety, and impulsivity. the population of online poker players is largely heterogeneous, with experimental players forming a specific group. finally, the validity of the tools used to measure excessive or problematic gambling and irrational beliefs are not suitable for assessing online poker activity.discussion and conclusionsfuture studies need to confirm previous findings in the literature of online poker games. given that skills are important in poker playing, skill development in the frames of excessive use of online poker should be explored more in depth, particularly regarding poker experience and loss chasing. future research should focus on skills, self - regulation, and psychopathology of online poker players. |
obstructive sleep apnea (osa), a common condition in older adults affecting more males than females,1 causes intermittent nocturnal hypoxemia and is associated with inflammation, metabolic abnormalities, endothelial dysfunction, and poor control of diabetes mellitus and hypertension, which may lead to micro and macrovascular disease.2, 3, 4 osa has been associated with higher risk of clinical cardiovascular disease (cvd), including ischemic stroke and coronary heart disease, independent of traditional risk factors and severity of atherosclerosis.4, 5 it is unknown whether this relationship is related to microvascular disease.6, 7 some investigators have suggested microvascular disease may be a potential mediator for the association between osa and clinical cvd. however, current evidence for the association of osa with microvascular disease is conflicting. some brain imaging studies revealed inconsistent results for the association between osa and cerebral smallvessel disease.8, 9 in addition, although some cardiac perfusion scans showed that osa is associated with impaired myocardial microcirculation in patients with acute myocardial infarction, this finding may be attributable to the production of lipid microemboli from atheroma plaque rupture.10, 11 the retinal microvasculature is structurally and functionally similar to microvasculature elsewhere in the body.12 previous studies have demonstrated the relationship between retinal microvascular signs and cardiovascular risk factors and shown that these signs predict a range of cvd, including stroke, coronary heart disease, and congestive heart failure.13, 14 retinal arteriolar narrowing is strongly related to hypertension and age,15 while retinal venular widening is related to cigarette smoking, inflammation, atherosclerosis, and metabolic abnormalities such as obesity, hyperglycemia, and diabetes mellitus.13, 16 retinopathy signs, specifically microaneurysms, hemorrhages, and cotton wool spots found in patients with diabetes mellitus are also prevalent in the general population (5% to 10%), and may be related to age, obesity, hyperglycemia, inflammation, and elevated blood pressure (bp).13 several retinal imaging studies have been used to evaluate the association between sleepdisordered breathing and retinal microvascular signs.17, 18, 19, 20, 21 these studies showed conflicting results. notably, results from a recent analysis of the multiethnic study of atherosclerosis (mesa) data visit 2 (20022004), in which a sample of 5803 participants underwent both a selfadministered sleep history questionnaire and retinal photography, found that physiciandiagnosed sleep apnea (pdsa) was associated with retinal arteriolar narrowing in women only.21 there was no association between pdsa and retinal vascular calibers in men. the clinical course of osa differs between men and women with women on average having less severe sleep apnea than men at younger ages, with differences narrowing after menopause.22 prior research suggests a sex difference in the associations between osa and clinical cvd.23 therefore, the association between osa and retinal microvascular signs may differ by sex. since pdsa was not an objective measure of osa severity in the previous mesa study,21 we used rigorously collected data from polysomnography (psg) and retinal photography in a large multiethnic general population in the mesa visit 5 (20102012) to quantify the sexspecific association between osa and retinal microvascular signs. the study design for mesa has been published elsewhere.24 in brief, mesa is a longitudinal cohort study designed to investigate the prevalence, correlates, and progression of subclinical cvd in individuals without clinical cvd at baseline. the cohort includes 6814 women and men aged 4584 years old recruited from 6 us communities (baltimore, md ; chicago, il ; forsyth county, nc ; los angeles county, ca ; northern manhattan, ny ; and st. the participants were 38% white, 28% african american, 22% hispanic, and 12% chinese. this study was approved by the institutional review board of each study site, and written informed consent was obtained from all participants. in conjunction with the fifth mesa examination (april 2010february 2012), all mesa participants were offered fundus photography, and except for those reporting regular use of oral devices, nocturnal oxygen, or nightly positive airway pressure devices, all participants were also invited to participate in the mesa sleep ancillary study, which included inhome psg. of 4077 participants approached for psg, 147 (3.6%) were ineligible and 141 lived too far away to participate. of the remaining 3789 participants, 2261 participated in the sleep exam (59.7%) and 2060 had successful psg data. we further excluded those with poor retinal image quality in both eyes, and those with missing data on relevant variables, leaving a sample of 1808 individuals (87.8%) aged 54 to 93 years for the analysis of retinal vascular calibers and another sample of 1831 individuals (88.9%) for the analysis of retinopathy signs (figure). flow diagram to select the eligible mesa sleepeye cohort, 20102012. mesa indicates multiethnic study of atherosclerosis. a 15channel psg recording (compumedics somte system ; compumedics ltd., abbotsville, au) including electroencephalography, electrooculography, chin electromyography, oxyhemoglobin saturation (finger pulse oximetry), chest and abdominal excursion (inductance plethysmography), airflow (oral and nasal thermocouple), leg movements, body position, and ambient light was taken in the participant 's home. the psg data were transmitted to the centralized reading center in the brigham and women 's hospital (boston, ma) for review and scoring by a certified polysomnologist masked to all other data. sleep stages and electroencephalography (cortical) arousals were scored based on published guidelines and adapted for unattended studies using methods from the sleep heart health study, as detailed.25 apnea was scored when the thermocouple signal flattened or nearly flattened for > 10 s. hypopnea was scored if the amplitude of the sum of the abdominal and thoracic inductance signals or the nasal pressure flow signal decreased by 30% or more for 10 s. apneas were classified as obstructive or central based on absence or presence of respiratory effort during the event. specialized software was used to link apnea and hypopnea with data from the oxygen saturation and electroencephalography signals, allowing each event to be characterized according to the degree of associated desaturation and arousal. in this analysis, hypopnea index (ahi) defined as the average number of obstructive apneas plus hypopneas associated with a 4% desaturation per hour of objectively measured sleep.26 intraclass correlation coefficients for within and betweenscorer reliability exceed 0.94. fundus photography was performed in both eyes of each participant according to a standardized protocol using a 45 digital nonmydriatic camera.27 all images were sent to the ocular epidemiology reading center at the university of wisconsin (madison, wi) and were evaluated by trained graders masked to participants characteristics. retinopathy was considered present if the graders found any lesions as defined by the early treatment diabetic retinopathy study severity scale, including retinal hemorrhages, microaneurysms, cotton wool spots, intraretinal microvascular abnormalities, hard exudates, venous beading, retinal neovascularization, and other lesions of proliferative diabetic retinopathy.28 retinal vascular caliber was measured with a computerbased program following a detailed protocol.28 for each photograph, all retinal arterioles and venules coursing through a zone between 0.5 and 1disc diameter away from the optic disc margin were measured as the central retinal arteriolar equivalents and venular equivalents.29, 30 the average of the right and left eye measurements was taken for both central retinal arteriolar equivalents and central retinal venular equivalents in each participant. if retinal vascular diameter could not be measured in both eyes, the eye with the available photograph was used. the reproducibility of retinal vascular measurements has been reported previously with intra and intergrader intraclass correlation coefficients ranging from 0.78 to 0.99.14, 15 all participants underwent an interview and were assessed for cvd risk factors at the fifth examination. body mass index (bmi) was calculated as weight (kg)/height squared (m). packyears of cigarette smoking were estimated from age of starting to quitting (or current age among current smokers)(cigarettes per day/20). hypertension was defined as systolic bp 140 mm hg, or diastolic bp 90 mm hg, or use of antihypertensive medication. diabetes mellitus was defined as fasting glucose 126 mg / dl or the use of hypoglycemic medications. hba1c was measured on the tosoh a1c 2.2 plus glycohemoglobin analyzer (tosoh medics, inc, hercules, ca) using automated highperformance liquid chromatography. glomerular filtration rate was estimated according to the chronic kidney disease epidemiology collaboration equation.31 micro and macroalbuminuria were defined by urinary albumin creatinine ratios of 30 to 299 mg / g and 300 mg / g, respectively. total cholesterol and highdensity lipoprotein cholesterol were measured from blood samples obtained after a 12hour fast. the severity of osa was classified by ahi (events / h) as none (10 s. hypopnea was scored if the amplitude of the sum of the abdominal and thoracic inductance signals or the nasal pressure flow signal decreased by 30% or more for 10 s. apneas were classified as obstructive or central based on absence or presence of respiratory effort during the event. specialized software was used to link apnea and hypopnea with data from the oxygen saturation and electroencephalography signals, allowing each event to be characterized according to the degree of associated desaturation and arousal. in this analysis, hypopnea index (ahi) defined as the average number of obstructive apneas plus hypopneas associated with a 4% desaturation per hour of objectively measured sleep.26 intraclass correlation coefficients for within and betweenscorer reliability exceed 0.94. fundus photography was performed in both eyes of each participant according to a standardized protocol using a 45 digital nonmydriatic camera.27 all images were sent to the ocular epidemiology reading center at the university of wisconsin (madison, wi) and were evaluated by trained graders masked to participants characteristics. retinopathy was considered present if the graders found any lesions as defined by the early treatment diabetic retinopathy study severity scale, including retinal hemorrhages, microaneurysms, cotton wool spots, intraretinal microvascular abnormalities, hard exudates, venous beading, retinal neovascularization, and other lesions of proliferative diabetic retinopathy.28 retinal vascular caliber was measured with a computerbased program following a detailed protocol.28 for each photograph, all retinal arterioles and venules coursing through a zone between 0.5 and 1disc diameter away from the optic disc margin were measured as the central retinal arteriolar equivalents and venular equivalents.29, 30 the average of the right and left eye measurements was taken for both central retinal arteriolar equivalents and central retinal venular equivalents in each participant. if retinal vascular diameter could not be measured in both eyes, the eye with the available photograph was used. the reproducibility of retinal vascular measurements has been reported previously with intra and intergrader intraclass correlation coefficients ranging from 0.78 to 0.99.14, 15 all participants underwent an interview and were assessed for cvd risk factors at the fifth examination. body mass index (bmi) was calculated as weight (kg)/height squared (m). packyears of cigarette smoking were estimated from age of starting to quitting (or current age among current smokers)(cigarettes per day/20). hypertension was defined as systolic bp 140 mm hg, or diastolic bp 90 mm hg, or use of antihypertensive medication. diabetes mellitus was defined as fasting glucose 126 mg / dl or the use of hypoglycemic medications. hba1c was measured on the tosoh a1c 2.2 plus glycohemoglobin analyzer (tosoh medics, inc, hercules, ca) using automated highperformance liquid chromatography. glomerular filtration rate was estimated according to the chronic kidney disease epidemiology collaboration equation.31 micro and macroalbuminuria were defined by urinary albumin creatinine ratios of 30 to 299 mg / g and 300 mg / g, respectively. total cholesterol and highdensity lipoprotein cholesterol were measured from blood samples obtained after a 12hour fast. the severity of osa was classified by ahi (events / h) as none (10. in the wisconsin sleep cohort study,18 shankar subsequently reported that moderate / severe sleepdisordered breathing (ahi 15) was associated with retinal venular widening, but not with retinal arteriolar narrowing in men or women. rudrappa showed that osa may promote diabetic retinopathy, whereas banerjee reported no association.19, 20 in line with sleep heart health study and wisconsin sleep cohort study,17, 18 our analysis revealed a nonlinear inverse association between ahi and retinal arteriolar calibers, an association between moderate / severe osa and retinal venular widening in men, and an association between severe osa with retinal microaneurysms in women. those findings from the earlier study in mesa appear to contradict the present study results.21 although pdsa may be a useful surrogate for more severe osa in mesa,35 it is likely those with unrecognized osa might be misclassified to the unaffected group. in fact, the median ahi levels, obtained by the psg in the mesa visit 5 for men selfreporting in mesa visit 2 as unaffected, habitual snoring, and pdsa, were 10.8, 15.3, and 25.9, respectively. more than half of the men selfreporting that they were unaffected at visit 2 actually had osa when objectively measured by psg at visit 5. since the association of osa with retinal arteriolar calibers was not dose dependent in men, a negative result using selfreport data may be erroneous and a direct result of osa misclassification in the reference group. furthermore, unrecognized sleep apnea may be more common in women, in whom a pdsa may identify the most severely affected individuals. in contrast to the 70 women with pdsa by selfreport at mesa visit 2 (2.3% of the total female cohort in the prior mesa analysis), in the present study, there were 87 women with severe osa and 229 women with moderate or severe osa, accounting for 8.8% and 23.1% of the total female cohort, respectively. in the earlier analysis, women with pdsa were older and had more severe osa resulting in a positive association between pdsa and retinal arteriolar narrowing. several mechanisms may account for the nonlinear inverse association between osa severity and narrower retinal arterioles in men. retinal arterioles are dilated in response to hypoxia.36 once reoxygenation occurs, retinal arterioles are constricted due to elevated concentrations of endothelin1 acting on eta receptors.37, 38 endothelin1 concentrations may be increased proportionally to osa severity,39 and have a dosedependent effect on retinal arteriolar constrictions.40 the effect of endothelin1 may be modified by antihypertensive therapy in osa. for example, use of blockers could reduce the secretion of endothelin1 from endothelium,41 and calcium channel blockers attenuate the effect of endothelin1 on arteriolar constrictions.42 therefore, the blunting ahi association with smaller retinal arterioles in men may be explained by multiantihypertensive medications with highdose use for resistant hypertension in severe osa. the sensitivity of eta receptors to endothelin1 is much stronger in men than in women,43 which may explain the observed sex difference in the association between osa and retinal arteriolar narrowing. additionally, an animal study suggested that the sensitivity to endothelin1 may decline with age, especially in females.44 on the other hand, men but not women with severe osa have been reported with higher risk of cardiac remodeling such as congestive heart failure, which elevates pulmonary wedge pressure and may affect retinal venular widening.23 systemic inflammation and hyperglycemia, which are related to severe osa, may cause diabetic retinopathy.3, 13, 45 however, men with severe osa seemed to have lower risk of diabetic retinopathy. this finding could be explained partly by the hypothesis that among individuals with severe osa, retinal arteriolar dilatation occurred less in men, which may prevent blood overflow to the retina, possibly lowering the risk of retinal microaneurysms presenting as capillary leak despite chronic inflammation status.46 in addition, some data indicate more endothelial dysfunction in women with osa compared to men,47 possibly increasing the risk of retinal microaneurysms in women with osa. the strengths of our study include an objective classification of osa, the ethnic diversity of the mesa sleep cohort, the availability of digitally acquired retinal data on a variety of specific retinal signs, and the availability of a wide range of data on other covariates. almost all of the women in the current study were postmenopausal, which may mitigate the effect of sex hormones on the associations of osa with retinal signs. data on some potential confounders such as inflammatory markers were not available and, as a result, we were not able to adjust fully for degree of inflammation. only 50.5% of mesa visit 5 participants contributed psg data for this analysis, possibly leading to a selection bias, although the baseline profile of characteristics among those who contributed psg data and those who did not were similar. since psg was only obtained at a single visit, our analysis was crosssectional and could not address the temporal association between osa and retinal microvascular signs. finally, the present study performed many tests, and we are aware this could inflate overall type i error rate. due to the exploratory nature of this research problem, we selected the minimal requirement of multiple comparison procedure to satisfy statistical rigor and used p<0.025 as the significance level for the overall test of osa severity. however, in some comparisons, there were borderline significant results that need to be clarified in further large studies that have sufficient power to detect the statistical difference between groups. in mesa, the prevalence of osa differed by sex as did osa severity. similarly, the associations between osa severity and retinal microvascular signs may differ by sex. moderate / severe osa was associated with retinal vascular calibers in men, but not in women. in contrast, severe osa was associated with retinal microaneurysms in women but not men. further studies are necessary to explain the mechanisms underlying these sexspecific associations. a longitudinal followup for both osa status and retinal microvascular changes will help to clarify any temporal associations. moreover, whether sexspecific effects of osa manifest on the microvasculature in other sites, including arterioles, venules, and vasa vasorum, also deserves investigation. this research was supported by contracts n01hc95159 through n01hc95169 from the national heart, lung, and blood institute at the national institutes of health, by grants ul1tr000040, ul1rr025005 from the national center for research resources, r01hl098433 (mesa sleep, r21 hl121348) and t32hl069764. support for the visit 5 retinal component was provided by the intramural research program at the national eye institute, national institutes of health (ziaey000403). | backgroundobstructive sleep apnea (osa) is a common condition affecting more men than women. the relationship of osa with microvascular disease is unclear, complicated by possible sex difference. assessment of the relationship of osa with retinal microvascular signs in men and women may provide insights into such a relationship.methods and resultswe examined the sexspecific crosssectional association of osa severity with retinal vascular calibers in 1808 participants, and with specific retinopathy signs in 1831 participants from a sample of 2060 participants aged 54 to 93 years who underwent successful polysomnography in the multiethnic study of atherosclerosis, 20102012. osa severity was defined by the apnea hypopnea index (events / h) as none (< 5), mild (514.9), moderate (1529.9), and severe (30). as compared to no osa, moderate / severe osa in men was associated with retinal arteriolar narrowing (odds ratio [or ] and 95% ci for the narrowest quartile : 1.65 [1.002.71 ]) and retinal venular widening (1.80 [1.073.04 ] for the widest quartile), but not in women (odds ratio : 1.10 [0.671.81 ] and 0.91 [0.581.43 ], respectively) after adjusting for age, race / ethnicity, body mass index, packyears of cigarette smoking, alcohol intake, hypertension duration, diabetes mellitus duration, hba1c levels, lipid profile, micro/macroalbuminuria, estimated glomerular filtration rate, blockers use, antihypertensive therapy, and lipidlowering therapy. in contrast, severe osa was associated with retinal microaneurysms in women, but not in men (odds ratio : 3.22 [1.168.97 ] and 0.59 [0.271.30 ], respectively).conclusionsthe associations of osa severity with retinal microvascular signs may differ by sex. whether these findings were related to sex differences in osa exposure needs further investigation. |
the airway epithelium is the first barrier and first line of host defense in the airway. formerly considered a more inert barrier that kept the outside out and the inside in, it is now clear that epithelial cells participate in host defense and inflammation. the networks in which the epithelium participates indeed can orchestrate either or both, depending on whether these networks are activated normally or not. a more classical view of epithelial responses to injury and inflammation emphasized the ability of the epithelium to respond to insults by secretion of water and mucous into the airways and mediator secretion (e.g., cytokines and chemokines) into the local environment and into the circulation. in this view, the epithelial layer responded to physical injury by a process that included, in order, phagocytic clearance of damaged cells and material, proliferation of new epithelial cells from surviving nearby stem cells, differentiation (phenotype shifting may be preferred) to new, required cell subtypes such as ciliated and mucous (goblet) cells, and restoration of barrier function. over the past two decades, it has become clear that proper protection and repair of the airway mucosa against sustained damage may also depend on the processes that control programmed cell death, that is, apoptosis. apoptosis is a tightly regulated process of nonnecrotic cell death that is critical for normal tissue and organ homeostasis. cells undergo apoptosis through the activation of carefully regulated pathways that lead to their orderly shutdown and removal. in this paper, i examine the occurrence and function of apoptosis both in the normal airway epithelium and in the epithelium in several airways diseases. in the context of these diseases, epithelial cell apoptosis may be either a compensatory response, a pathogenetic consequence, or both. i limit this paper to discussion of central airways (tracheal and bronchial) epithelial cells with appropriate mention of small airway and alveolar epithelial cells where warranted and to the process of apoptosis, leaving aside other mechanisms of cell death such as necrosis and autophagy. in examining apoptosis in the airway epithelium, it should be noted that several methods examine epithelium both in situ and in culture. collection of full - circumference airways is useful to examine epithelial morphology, damage, proliferation, and apoptosis in a setting that preserves the architecture of the full - thickness airway. various morphologic and histologic strategies, including antibody labeling or electron microscopy, can be used. this method is limited to the study of specimens collected either by lung resection or at autopsy. endobronchial biopsies can be obtained more easily (compared to open lung biopsy or autopsy) and allow for both one - time and, in some special cases, repeated sampling of airways, but crush artifact may limit the ability to interpret morphological changes in the mucosal layer. endobronchial brushings can collect epithelial cells for subsequent culture or harvest of rna but provide no information about morphology. the culture of airway epithelial cells likewise can be useful to elucidate mechanisms but has limitations. primary cells typically have been grown in submersion culture, a method used for over four decades in many laboratories ; these have a monomorphic appearance that resemble basal airway epithelial cells. submersion culture can generate experiments quickly to test hypotheses and mechanisms but do not provide information about the morphology of epithelial subtypes and thus raises a concern about how applicable the results from these experiments are to the in situ state. epithelial cells can be grown in an air - liquid interface (ali), a more recent culture method that permits differentiation (a better term may be phenotype shifting) over a period of 2 to 5 weeks of culture into basal, columnar, and goblet cells that resembles a native epithelium [3, 4 ]. while more technically demanding, such cultures provide additional information about morphology and potential interactions between the epithelial subtypes. as with submersion culture, data from cells grown in ali culture may not be fully applicable to the in situ airway. finally, a number of airway epithelial cell lines have been generated over the past three decades. several of these, such as the 16hbe14o- and 1haeo- cell lines that are sv40 transformed from normal cells [5, 6 ] and the a549 lung adenocarcinoma cell line, have been popular in studies of epithelial cell apoptosis due to the ease of culture and the reproducibility of the cells over a number of passages. however, whether sv40 transformed or derived from cancer cells, it should be acknowledged that proliferation and apoptosis pathways and regulators may well be different in these cells versus primary cells and that cells in culture may not behave as epithelial cells in situ in their unique microenvironment. the culture of epithelial cells is that (done properly) there are no other cell types in the culture system. while the response of pure epithelial cells to a stimulus is useful in reductionist - style experiments, examining interactions between different cell types may be just as important. to meet this concern, dual - culture systems grow epithelial cells on a filter either in submersion or in air - liquid interface suspended above a second cell type (e.g., fibroblasts) grown either on the underside of the filter or in the bottom of the culture container. other dual - culture systems expose epithelial cells to bacteria (e.g., coculture or addition of pseudomonas aeruginosa), with subsequent examination of apoptotic markers. such biculture systems permit a limited examination of influences of these cells on epithelial cell apoptosis, or vice - versa. understanding the role of apoptosis in airway epithelium and interpreting the many studies done also require a clear awareness of the usefulness and limitations of each method of analysis. a recounting of apoptosis methods is well beyond this paper but two recent reviews outlining guidelines for the use and interpretation of assays to analyze cell death (apoptosis, autophagy, and necrosis) are useful reminders of the significant methodological and analytical issues [8, 9 ]. apoptosis is the orchestration of cell death by highly conserved genes in eukaryotes [1013 ] that permits the removal of damaged or unneeded cells from tissue without releasing cellular contents that would otherwise damage surrounding cells or elicit an inflammatory response. it is tightly and carefully regulated in normal circumstances but may be inappropriately activated or suppressed in diverse disease states. in contrast to cell necrosis, the principal features of apoptosis include shrinkage of the cell, condensation of the nucleus, dna fragmentation, fragmentation of the cell cytoskeleton, and eventual formation of an apoptotic body that is either shed or phagocytized. several reviews examine general mechanisms of apoptosis and are recommended [9, 12, 1517 ]. multiple signals that initiate apoptosis including death receptors, cytokines, heat and oxidative stress, and ionizing radiation link to a signaling cascade of serine proteases known as caspases. upstream caspases (e.g., caspase-8) work to collect receptor - mediated signals and initiate the death cascade, whereas downstream caspases (e.g., caspase-3) act upon targets in the both cell nucleus and cytosol (figure 1). pathway because it is activated by extracellular signals, involves ligation of cell surface death receptors [11, 13, 18, 19 ], members of the tumor necrosis factor (tnf) superfamily, such as cd95 (also fas or apo-1) [14, 20 ], tnfr1, dr3, dr4, dr5, dr6, edar, and p75ntr. each contains an exclusive, 80 amino - acid long domain, the death domain, essential to induce apoptosis [13, 21, 22 ]. when ligated, the receptors form homotrimers that recruit molecules into a death domain. activation of these domains (e.g., interaction of fas with fas - associated death domain or fadd, or the interaction of tnfr1 with the tnr - receptor - associated death domain or tradd) leads to formation of a death - inducing signaling complex (disc) [23, 24 ] and subsequently caspase activation [25, 26 ]. the cognate death receptor ligands generally are comprised of a c - terminal extracellular portion which interacts with the death receptor, a transmembrane region, and an n - terminal domain. the best - described ligands are cd95l (fasl), that bind cd95, tnf-, and the tnf - related apoptosis - inducing ligand (trail). it was originally considered to be expressed mostly by hematopoietic cells such as lymphocytes and dendritic cells, but also is demonstrated in immune - privileged sites and in states of chronic inflammation, and not only mediates cell death but also serves as an effector molecule to establish immune privilege and enhance cell survival [21, 27 ]. originally described as a transmembrane molecule, cd95l now is recognized to have a soluble variant cleaved from the cell surface by metalloproteases [28, 29 ] ; alternately, it is packaged with other lysosomal proteins in lysosomes and transported to the plasma membrane where it is then released into the external environment. tnf- has complex effects on airway epithelial cells and may both elicit and oppose apoptosis depending on context. cytokine that induces several effects in airway epithelium, such as (of many examples) the expression of the icam-1 adhesion molecule [3032 ] and il-6 and il-8 [3335 ]. the former is responsible for the cytotoxic, including apoptotic, effects of tnf-, whereas both receptors can interact with a series of adaptor proteins, the tnf - associated factors (traf). traf2 but not traf1 can initiate activation of the nf-b signaling cascade to elicit il-8 secretion [33, 34 ]. disrupting nf-b signaling can enhance tnf--mediated apoptosis ; likewise, activating nf-b signaling can suppress tnf--mediated apoptosis. thus, tnf--mediated cell death and inflammation exist in a balance that can be perturbed by several pathways. trail is a type ii membrane protein that induces apoptosis in a variety of target cells. in some cell types, trail binding to the death receptors dr4, dr5, and/or dcr2 may also activate the transcription factor nfb, leading to transcription of genes that actually antagonize death signaling pathways and promote inflammation [40, 41 ]. a second pathway that elicits apoptosis, type ii or the intrinsic pathway, is activated not by receptors but by stressors such as oxidative stress, dna damage, and starvation [14, 42 ] and has as its defining characteristic a requirement for increased mitochondrial permeability that then releases cytochrome c. cytochrome c combines with apaf-1 to cleave and activate procaspase-9 in a complex termed the apoptosome the mitochondria thus may serve as a central apoptotic executioner to integrate multiple, diverse internal signals that indicate cellular damage. activation of either pathway leads to cleavage and activation of common pathway caspases such as caspase-3 (figure 1) and commits the cell to an apoptotic death. both pathways are regulated by a family of proteins known as the inhibitors of apoptosis (iaps). most of these suppress caspases either by binding the active catalytic site of effector caspases, by preventing dimerization of caspase-9, by sequestering mitochondrial proteins, or by stimulating degradation and ubiquitination of caspases. these proteins have a conserved bcl2 homology domain that allows the family member to join to other members. the prosurvival members of the family (bcl2, bcl - xl, bclw, mcl1, a1, and boo / diva) have multiple bcl2 homology domains [14, 46 ]. in contrast, the proapoptotic protiens have a different number of bcl2 homology domains : bax and bak, for example, each has three such domains, and both function to increase mitochondrial membrane permeability and thereby release cytochrome c [14, 47 ]. other proapoptotic bcl proteins (bim, bid, puma) have an alternate bcl2 homology 3 (bh3) domain that binds to and inhibits prosurvival bcl2 family members, thus releasing bax and bak [48, 49 ]. a balance between prosurvival and proapoptotic bcl2 proteins determines life or death, and each family member may be activated or suppressed differently depending on the cell stress or death activator. our laboratory group first demonstrated this death receptor and the expression of its corresponding ligand cd95l (fasl), in primary central airway epithelial cells and cell lines in submersion culture and in airways collected from lung resection surgery (figure 2). ligation of cd95 using the ch11 antibody that cross - links the receptor activates caspase pathways and elicits cell death [20, 50, 51 ]. both cd95 and cd95l subsequently have been demonstrated in airway epithelium in patients with cystic fibrosis ; cd95l expression is markedly increased in these airways, which was also demonstrated in an epithelial cell line, htec, with a cf genotype. these observations, including that the cd95 receptor is functional, have since been replicated ; one such study suggests that epithelial cell apoptosis induced by cd95 ligation may be less important than that induced by tnf-. cd95 has been demonstrated in small airway epithelial cells (saec) in culture, and when compared to epithelial cells collected from larger, proximal airways, saec is more sensitive to cd95 ligation with a recombinant, soluble fasl. cd95 expression also has been demonstrated in type ii alveolar epithelial cells in humans and other mammals [5558 ] and may be involved in fetal lung development. cd95l expression in human airway epithelium may serve, as it is postulated to serve in other immune privileged sites such as retina, brain, and testis, as an immune barrier [20, 60 ]. airway epithelial fasl levels are increased in patients with severe asthma after steroid treatment, although it is possible that this increase in fasl levels reflects a more severe stage of disease. one recent paper demonstrates that transmembrane fasl on epithelial cells is cleaved by matrix metalloproteinase (mmp)-7 ; this in turn is upregulated by the th2-associated cytokine il-13. as this mmp is increased in asthmatic airway epithelium, this study suggests a mechanism whereby increased cd95l in asthmatic airways might serve either to reestablish the immune barrier (by activating apoptosis in inflammatory cells) or to perpetuate mucosal damage (by activating apoptosis in epithelial cells). these studies, taken together, make clear that both cd95 and its ligand are present and functional in airway epithelium both in vivo and in culture models and may be increased in expression in asthmatic epithelium. as noted previously, tnf- binds two distinct receptors : tnfr1 (also p60 tnfr) and tnfr2 (p80 tnfr). the former has an 80 amino - acid cystein - rich domain in its extracellular domain that can contain either a death domain, a traf binding domain, or a decoy domain. the death domain interacts with the tnfr - associated death domain protein (tradd), which in turn interacts with the fas - associated death domain protein (fadd) to activate caspase-8 [37, 64 ]. in this way, tnfr1 shares the same downstream signaling pathway and machinery as cd95. remarkably few studies have been done to examine tnfr - pathway - driven apoptosis in airway epithelial cells and cell lines. examined the effect of sputum sol phase collected from a cohort of patients with cystic fibrosis on apoptosis of primary human bronchial epithelial cells. the tnf pathway was activated, but a direct link to tnf- in the sputum sol phase was not demonstrated. another recent study demonstrated that tnf- stimulated caspase-3 activation and il-8 expression in primary airway epithelial cells via phosphorylation of p38 mitogen - activated protein kinase (mapk), an effected potentiated by concurrent exposure to nontypeable haemophilus influenzae. other stress - activated protein kinases such as c - jun n - terminal kinase (jnk) are well recognized to suppress tnf--stimulated apoptosis (reviewed in), but this has not been studied in airway epithelium. in addition to receptor - driven activation that directly initiates apoptosis, tnfr activation may modulate apoptosis by indirect mechanisms, in addition to any survival signals and inflammatory signals delivered by its activation of the nf-b signaling pathway. for example, treatment with tnf- in primary proximal airway epithelial cells enhances subsequent apoptosis elicited by exposure to cd95l, demonstrating a clear potential interaction in these pathways. tnf- treatment in the h441 and a549 lung adenocarcinoma lines elicits gene expression of both traf1 and ciap2 and that both were increased in the lungs of infants with fatal bronchopulmonary dysplasia. these signaling interactions are complex but suggest potential therapeutic strategies in manipulating death versus survival pathways in tnfr - mediated signaling. the expression of trail, a ligand for several death receptors, is increased, as demonstrated by immunohistochemical labeling, in the epithelium of endobronchial biopsies collected from asthmatic airways. however, in contrast to the clear presence of cd95, no published studies have demonstrated the presence of potential partner death receptors, including dcr1, dcr2, dr4, or dr5, in airway epithelium in normal human airways, though one paper demonstrates both dr4 and dr5 in guinea pig airways, and one paper demonstrated the r1 and r2 receptors for trail in nonbronchoscopically obtained epithelial cells from children suffering from rsv infection accompanied by respiratory failure and mechanical ventilation. trail may bind one of the tnfrs that are induced during diseases processes, which then may activate cell death pathways via relatively novel signals that include phosphorylation of p38-mapk. the relative expression of and signaling pathways connected to these receptors and the circumstances of their expression in health and in airways diseases in human airway mucosa require further exploration. as noted previously, it provides a mechanism to remove damaged cells without provoking an inflammatory response. an additional beneficial role is, along with cell proliferation, regulating the number of epithelial cells. the cell cycle rate in resting mammalian large airway epithelium in situ, expressed as the proportion of dividing cells counted in thymidine incorporation assays, is 80% cell death in less than 8 hr (as several of many examples, see [64, 91, 92 ]). one might ask, if epithelial cells express both ligand and receptor, why one epithelial cell does not kill its neighbor ? the answer may be that epithelial cells, at least under normal conditions in the airway (or in standard culture), are relatively resistant to cd95-induced death signaling, either by an inability to cluster and activate the receptor trimer required for fadd activation or further along the signaling pathway. the first is that either a second costimulatory signal is required for maximal killing. no such signal has been demonstrated in airway epithelium, but signals that sensitize cells to death receptor stimulation are seen in other systems. for example, ifn- and tnf- sensitize human endometrial stromal cells, normally apoptosis resistant, to cd95-mediated cell death due to an upregulation of cd95 expression, and interleukin (il)-10 protects mouse intestinal epithelial cells from fas - induced apoptosis by downregulating fas expression and regulating the expression of death domain components. a second possibility is that a change in the environment elicits a reconfiguration of the receptor that makes it more amenable to activation. data to support such a hypothesis in airways are lacking, but, in other systems, it is clear that cd95 receptor regulation in turn regulates the ability to switch on apoptosis. for example, expressing a mutant cd95 that lacks a death domain, and therefore can not initiate disc formation, blocks apoptosis ordinarily elicited with an anti - cd95 antibody, even as the receptor trimers aggregate. expression of the cellular flice - like inhibitory protein (c - flip), a component of the death - effector domain, can either inhibit or activate both cd95 and other death receptors dependent on context (reviewed in), but this regulator has yet to be described in airway epithelium. in the normal airway epithelium then it is clear that apoptosis, like proliferation, is tightly regulated to the point that it is uncommonly seen as best as can be detected with current methods. epithelial cells can respond to death stimuli in the culture environment but even then there is relative resistance. understanding the default setting of no death may help us to understand compensatory responses and disease states in which apoptosis clearly is activated. both in disease states such as asthma and copd and after various environmental exposures, significant goblet cell hyperplasia (gch) may be seen [9698 ] in airway mucosa. cytokines such as il-13 and il-4 can stimulate phenotype shifting of large airway basal or small airway epithelial (clara) cells to mucoid cells by inducing mucin expression [99104 ] ; two separate reports suggest that ciliated cells may also shift to a mucoid phenotype under certain conditions [105, 106 ]. the bacterial wall inflammatory factor lipopolysaccharide (lps) also can induce gch in cell culture models of epithelial cell phenotype shifting [107, 108 ] as can irritants such as cigarette smoke. there may also be an increase in the total number of epithelial cells over time with most of the new cells manifesting a mucoid phenotype. resolution of goblet cell hyperplasia is associated with downregulation of mucin protein expression and either phenotype shifting of these cells to a clara or serous cell phenotype or absolute reduction of goblet cell numbers by apoptosis [111113 ]. the appearance of new goblet cells in gch may be due to an inhibition of apoptosis. harris and colleagues demonstrated increased expression of bcl-2 in mucous cells after lps instillation in norway rats ; bcl-2 positive mucous cells decreased to normal levels just prior to resolution of gch. in their study, stable overexpression of bcl-2 increased lps - induced gch compared to wild - type mice. a similar expression of bcl-2 and gch was seen in nasal epithelium after ozone exposure in rats. resolution of gch may require more than downregulation of bcl-2 : expression of the proapoptotic mitochondrial regulator bax, which can heterodimerize with bcl-2 and block its function, is associated with the loss of goblet cells in the resolution phase of gch, and treatment with agents such as ifn-, which increases bax expression, is associated with increased clearance of goblet cells, even as treatment with an anti - fas antibody fails to clear these cells. other modulatory pathways such as that coupled to the epidermal growth factor receptor (egfr) also may modulate gch induced by either allergen exposure in cultured h292 epithelial cells or sendai virus exposure in mice, such that blocking egfr signaling induced apoptosis in goblet cells. these studies serve as one striking example of how apoptosis may be intimately involved in regulating the phenotype and presence of airway epithelial cells in response to environmental perturbations. both the appearance and disappearance of goblet cells may require (resp.) inhibition or initiation of apoptosis. both offer potential therapeutic checkpoints to drive the airway mucosa towards a more homeostatic model in response to chronic illness. while increased apoptosis is thought to contribute to airway damage and pathogenesis, it may also be a consequence of reparative processes that attempt to remove dead, dying, or damaged cells. in addition to the issues of detachment of apoptotic cells into the airway lumen and the clearance of apoptotic bodies by professional phagocytic cells, it can be difficult to distinguish apoptotic from necrotic cells in airway and lung biopsies. further, a measurement of apoptosis at a single time point (e.g., via endobronchial biopsy) may not reflect either the state of damage in that airway at that time point, of the disease state elsewhere in the lung at that time point or of the course of the disease over time. repeated measurements of epithelial cell apoptosis in vivo over time are currently not possible, as there are no specific markers to be found in sputum (noting the recent study of chimenti. that suggests at least the possibility of identifying tunel - positive epithelial cells in sputum collected from asthmatic subjects), bronchoalveolar lavage fluid, or exhaled breath condensate, and repeated biopsy of the airways, in addition to methodological problems, has obvious limitations in terms of patient access and risk. the discussion that follows for each disease then is based on limited in vivo studies supplemented by mouse and culture models. by the end of the 19th century, henry hyde salter had recognized the appearance of an asthmatic airway with inflammation and hypertrophy of smooth muscle, and sir william osler had described the relation of allergy, hay fever, familial predisposition, childhood onset, the presence of leyden crystals and curschmann spirals in sputum, and paroxysms to asthma. in the early to mid 20th century, asthma was seen as a disease of intermittent bronchospasm and treated with various bronchodilators. but from the 1920s, inflammation was recognized as pathogenetic to asthma (for a review see), and, more recently, the concept of remodeling, a description of a chronically inflamed, narrowed asthmatic airway with smooth muscle hypertrophy, a thickened basement membrane, and importantly for this discussion chronic, persistent, focal to widespread epithelial damage along with goblet cell hyperplasia as an end result of inflammation, has defined the disease process [122, 123 ]. the epithelium is a target of inflammatory and physical insults in both acute asthmatic inflammation and in chronic asthmatic remodeling. epithelial injury is common even when the clinical state of asthma is mild [123, 124 ] and is persistent over time. epithelial damage correlates with airway hyperreactivity and may be seen in newly diagnosed asthma [125, 126 ]. epithelial damage is more than a manifestation of injury : it is an effector of the airway inflammation that marks chronic asthma [127129 ]. epithelial injury leads to disordered regulation of submucosal myofibroblasts and fibrinogenesis [130, 131 ] and release of chemokines such as il-8 and eotaxin [132, 133 ]. mucosal damage may be extensive in severe or fatal asthma but is more focal in mild - moderate asthma [125, 135 ]. epithelial cell apoptosis is difficult to assess in human asthma, both for morphological issues such as sampling bias and the aforementioned risk of underestimating apoptosis in damaged airways, and issues due to the variable nature of the disease and variable methods used to classify patients. studies of apoptotic markers in endobronchial biopsies collected from asthmatic subjects have shown variable results : for example, vignola. examined tunel, bcl-2, and p53 labeled in a cohort of asthmatics, either untreated or treated with inhaled or oral corticosteroid (cs) agents, and in control subjects. in this study no control subject, and few asthmatic subjects, had any tunel - positive cells in the epithelial layer ; while p53 was not expressed in any group, subjects with asthma, treated or not, had a higher number of cells labeling for bcl-2 versus control. in contrast, a study by cohen. examined both apoptosis and proliferation in bronchial biopsies collected from normal subjects and subjects with mild or severe asthma. in this study, there was a greater number of tunel - positive cells in biopsies of severe asthmatics compared to controls, along with decreased bcl-2 expression and increased proliferation as noted by labeling for the marker ki-67. these two studies may be reconciled on the basis of disease severity, as the cohen study did not demonstrate an increase in apoptosis in mild asthmatics. yet another study by trautmann. demonstrated apoptotic epithelial cells in a small cohort of patients with mild, persistent asthma, as demonstrated by tunel and hoechst labeling on endobronchial biopsies. in our own laboratory, apoptotic epithelial cells can be demonstrated clearly in endobronchial biopsies of subjects with chronic, persistent asthma ; such labeling is almost never seen in biopsies collected from normal volunteer subjects (figure 3). therefore, as best can be demonstrated to date, there are relatively few apoptotic cells present in the airway epithelium of mild asthmatics ; more significant apoptosis and proliferation are seen in asthma and may be related to both chronicity and severity. corticosteroid treatment clearly suppresses inflammation in a large majority of asthmatic patients [136139 ] and in mouse asthma models of allergen - induced airway inflammation [137, 140 ], though it is clear that corticosteroids do not alter the natural history of asthma. in addition to the effects on the number and function of inflammatory cells that ordinarily infiltrate the airway mucosa in chronic asthma, cs treatment also inhibits the release of inflammatory mediators secreted by epithelial cells such as rantes, gm - csf, and eotaxin. however, the role of corticosteroids on epithelial cell survival and death is less clear. that some asthmatic subjects have improved airway mucosal integrity and epithelial cell anatomy following treatment with inhaled cs is unequivocal : for some subjects, clinical improvement is accompanied by evidence of restoration of normal epithelial anatomy as demonstrated on endobronchial biopsies. further, cs treatment of cultured epithelial cells may inhibit cell death induced by cytokines such as ifn- or tgf-. dexamethasone at concentrations of 1 mm inhibits ifn- induced cell death in the a549 peripheral lung adenocarcinoma cell line, perhaps by inducing expression of hiap. contradictory reports suggest that tgf- can induce epithelial cell apoptosis that is blocked by concurrent treatment with budesonide or can prevent epithelial cell apoptosis that is induced by dexamethasone. balancing these studies are reports that cs treatment of cultured human airway epithelial cells and cell lines may induce apoptosis [50, 147149 ]. either dexamethasone or budesonide in concentrations of 110 m in culture, a dose that when adjusted for airway surface area and sol volume calculates to the high end of the point concentration of an inhaled corticosteroid on epithelium in vivo, elicits caspase - mediated apoptosis that requires disruption of mitochondrial polarity and release of cytochrome c. overexpressing either bcl-2 or bcl - xl inhibits cs - induced apoptosis in this model. a follow - up study demonstrated that dexamethasone treatment in balb - c mice for 3 days to 4 weeks also elicited increased epithelial cell apoptosis, as measured by tunel labeling and labeling for the 85 kd fragment of polyadenine ribopolymerase (parp), a nuclear enzyme cleaved early in apoptosis. one additional study also suggests that concurrent treatment of cultured human airway epithelial cells and cell lines with the beta - adrenergic agonists albuterol or formoterol can block cs - induced apoptosis this may provide one potential explanation as to why relatively few apoptotic epithelial cells are seen in the airways of asthmatic subjects, as most of these subjects receive such agents as part of their antiasthma controller therapy. mouse models of airway inflammation induced by exposure to allergen are a time - honored, useful model to explore the effects of an allergen on airway structure and function and, unlike in human studies, permit careful assessment of mechanism and function. the classic model involves the sensitization and challenge to ovalbumin (ova), followed by collection of tissue, bal fluid, or other samples at key time points following challenge. genetic manipulation of the mouse, adoptive transfer of selected lymphocytes, or other treatments can modify airway inflammation. from these many studies, a clear picture of murine airway inflammation has developed that has informed our understanding of human airway inflammation in asthma. truong - tran. examined apoptosis markers such as caspase-3 activity in an ova model in balb / c mice. allergen challenge elicited airway inflammation and airway hyperresponsiveness, as expected, and also an increased number of apoptotic bodies in the airway mucosa and increased immunolabeling for activated caspase-3 ; both were increased by concurrent dietary depletion of zinc, a factor that the authors suggest may be protective against epithelial damage. a second study from our laboratory examined epithelial cell apoptosis after ova challenge with and without concurrent corticosteroid therapy. this study grew from an earlier observation (discussed above) that corticosteroid treatment could induce apoptosis in cultured primary human airway epithelial cells and cell lines. we hypothesized that corticosteroids could cause cell death of airway epithelium in vivo, and the resulting loss of epithelial cells might explain in part the damage to and denudation of the airway mucosa in chronic asthma, despite control of other markers of inflammation. to test this, balb / c mice were sensitized and challenged to ova, and both sensitized mice and control, unsensitized mice were treated at selected time points with dexamethasone in doses calculated to be at the high end of a therapeutic regimen for asthma. allergen challenge also elicited increased tunel and p85-parp labeling over the first 14 days after challenge, and this was not decreased by concurrent corticosteroid treatment. these two papers have made clear the association of epithelial cell apoptosis and allergen - induced airway inflammation. human studies to examine the association and to perhaps demonstrate causality of allergen challenge on epithelial cell apoptosis, however, have not been done to date. one paper by robertson. examined the expression of the tnf family mediator trail, which can induce apoptosis and its receptors dcr2, dr4, and dr5 following segmental allergen challenge by bronchoscopy in a cohort of asthmatic and nonasthmatic subjects with ragweed allergy. in asthmatic subjects, instillation of ragweed into the airways elicited increased epithelial trail labeling within 2 days along with decreased immunostaining of dr4 and dr5 in eosinophils and macrophages. a substantial proportion of asthmatic patients demonstrate worsening symptoms and airway inflammation as a result of exposure to cold, dehumidified air associated with exercise [152154 ]. cold air challenge and hyperpnea both are clinical and laboratory models used to induce bronchoconstriction in susceptible subjects with airway hyperreactivity [155, 156 ]. athletes, even those not suspected of having asthma, may also have airway inflammation in response to cold air exposure [157159 ]. even in more moderate environments such as swimming or rowing in which there is substantial hyperpnea, elite athletes may have inflammatory cells present in induced sputum and in airway lavage [159, 160 ]. airway epithelial damage in athletes may be seen : for example, in a cohort of nonasthmatic long - distance runners, increased numbers of shed bronchial epithelial cells and of tunel - positive apoptotic epithelial cells were seen in induced sputum after a half - marathon race. these findings have been explored in a mechanistic model in mice, in which lung sections collected from sedentary and endurance - trained mice were examined. compared to sedentary mice, the bronchiolar epithelium of endurance - trained mice demonstrated a progressive loss of ciliated cells and both increased apoptosis and increased proliferation, along with infiltration of cd45 + leukocytes into the mucosa. these changes may represent an adaptive response to increased ventilation during exercise. in summary, asthma, asthma treatment, and th2-mediated airway inflammation are associated with central airway epithelial cell apoptosis. the significance of this cell death is not yet clear, nor is it clear whether epithelial cell apoptosis represents a compensatory, adaptive response to clear damaged or dying cells or represents a maladaptive, pathologic response that over time contributes to the epithelial injury and airways remodeling process that characterizes chronic asthma. viral infection of the airways is increasingly demonstrated as a leading cause of exacerbations of clinical asthma, particularly in childhood. infections with viruses such as adenovirus (adv), rhinovirus (rv), respiratory syncytial virus (rsv), influenza virus, and parainfluenza virus (piv) occur early in the lower respiratory tract, are association with exacerbations and hospitalizations for asthma [163, 164 ], and are recognized as an important risk factor in early childhood for the development of persistent asthma later in life [165, 166 ]. patients with asthma with frequent viral - induced exacerbations have worse pulmonary function and a worse clinical course than patients without such frequent infection, a finding that may first develop in infancy. frequent viral infection in infancy may alter th2 responses, particularly when combined with allergen exposure. the airway epithelium is a central target of viral infection and replication, and epithelial cell damage, release of cytokines, and other factors. apoptosis then can be seen as a central part of host defense ; viruses may use apoptosis to subvert host defense for their own survival. one broad method for doing so is for a virus to provoke apoptosis of the infected cell. the potential advantage of this is that it may facilitate viral egress after replication and thus spreading and survival of the virus (reviewed in). this was clearly seen in the study of kotelkin and colleagues in which rsv infection of cultured primary tracheal or small airway epithelial cells, or cell lines, elicited apoptosis that was associated with both caspase-8 (receptor mediated type i) and caspase-9 (mitochondrial associated type ii) activation and with expression of both pro- and antiapoptotic bcl-2 family members. interestingly, rsv also induced trail expression and expression of both the dr4 and dr5 receptors, not seen in normal, uninfected cells. a more recent study demonstrated that rsv infection was associated with recovery of soluble trail in airway lavage fluid and the expression of the trail receptors r1 and r2 in the airway epithelium of children with rsv infection and mechanical ventilation. a third study examined the apoptosis - inducing effect of rsv on primary nasal, tracheal, and bronchial epithelial cells grown in culture. in this study, adenoviral infection also can induce apoptosis in epithelial cells. in a guinea pig model of adv infection, singhera and colleagues demonstrated increased, time - dependent apoptosis, as measured by detection of the p85 fragment of parp, along with expression of the dr4 and dr5 receptors. interestingly, corticosteroid treatment delayed apoptosis in cultured epithelial cells following adv infection and allowed increased viral particle production. in a chronic infection model, infection plus sensitization and challenge with ovalbumin led to increased numbers of apoptotic epithelial cells ; again, corticosteroid treatment decreased the number of apoptotic cells. these experiments suggest that corticosteroid use may actually contribute to decreased viral clearance and thus prolonged infection. while rv infection is less toxic to epithelial cells in different models, it can induce apoptosis via activation of caspase-9 in cultured, nonpolarized epithelial cells in culture. however, apoptosis was not seen in rv - infected, polarized, differentiated epithelial cells, even as rv infection disrupted the epithelial barrier function as measured by transepithelial resistance. influenza a infection elicits an inflammatory airway response with epithelial cell secretion of cytokines and chemokines. one study has examined influenza - a - infection - induced apoptosis in the h292 human mucoepidermoid bronchiolar carcinoma cell line. in this study, brydon. demonstrated that inhibiting apoptosis using caspase inhibitors increased chemokine secretion, suggesting that the observed inflammatory response in influenza would be greater if cell death did not occur. another study demonstrated that, in h292 cells, influenza infection elicited apoptosis by upregulating mitogen - activated protein kinase signaling pathways that include c - jun and p38-mapk. the avian h9n2 influenza virus elicits apoptosis in primary, polarized, differentiated airway epithelial cells with activation of caspase-9 and release of mitochondrial cytochrome c. in this study, ifn- was antiviral and antiapoptotic, which fits the known role of interferons in blocking viral infection. in this light, a study by chan. demonstrated that more differentiated airway epithelial cells in culture were more resistant to h5n1 influenza infection ; the authors noted that an undifferentiated epithelium, as might be seen following damage due to virus or other agents, could be easily infected. examining apoptosis in both undifferentiated or growing epithelial cells versus a tightly organized differentiated epithelium with a highly polarized and tight barrier may be required to understand how influenza and other viruses use cell death to their advantage in clinical infection. viral infection also may suppress apoptosis so as to ensure their replication and survival by preventing the death of the cell. while cytomegalovirus and certain herpesviruses are known to inhibit apoptosis (reviewed in), no data suggest that such suppression occurs after viral infection of airway epithelium. taken together, these studies suggest that infection with viruses that commonly cause respiratory disease such as rsv, adv, and influenza elicit apoptosis of airway epithelium. the interplay between epithelial damage and loss, inflammation, and viral replication is not yet clear from these studies. studies are needed to demonstrate whether blocking apoptosis in viral infection leads to clear changes in the inflammatory state and epithelial damage, and better studies in human subjects, particularly children, are needed to demonstrate the association of epithelial cell damage, loss, and apoptosis with ongoing airway inflammation and loss of asthma control. though challenging, such studies will provide important answers as to whether inhibiting apoptosis in the setting of viral infection leads to better, or worse, clinical outcomes. cystic fibrosis (cf) is a multisystem, genetic disease caused by mutations in the gene encoding cftr, which leads to decreased chloride secretion and increased sodium absorption, with resulting decreases in lumenal liquid, in airways, the pancreas, and other organs lined by epithelial cells (reviewed in). in airways, this leads to dehydration of airway mucous with resulting poor mucous clearance, infection, particularly with organisms such as pseudomonas aeruginosa and staphylococcus aureus, inflammation, and, over time, bronchiectasis and fibrosis of the airway [180, 181 ]. clearly the epithelium is central to disease pathogenesis in cf, and airway inflammation along with damage to and loss of epithelial cells are prominent in established bronchiectasis and airway fibrosis in this disease. over the past decade, apoptosis as one of several mechanisms for airway epithelial cell loss in cf airways has become recognized. expression of cd95 and cd95l, along with markers of apoptosis such as dna fragmentation, was first reported by durieu. in a study of surgical lung lobectomies obtained from a small cohort of cf patients. in this study, cd95l expression was markedly increased in bronchial epithelial cells, and tunel labeling demonstrated apoptotic cells both in the mucosa and in submucosal gland epithelial cells. demonstrated increased bcl-2 presence in airway epithelium in lung blocks collected from patients with cf compared to normal airways ; this was most prominent in goblet epithelial cells. bcl-2 expression in this setting may be a general, compensatory response to permit survival or may permit preferential development of goblet cells that then would secrete increased mucous into the cf airway. apoptosis of cf - derived epithelial cells in culture also has been demonstrated. ligating cd95 induces apoptosis (as expected) in normal tracheal epithelial cell lines but increased apoptosis in the cf - derived cell line cft-2. the pseudomonas aeruginosa strain pao1 induces apoptosis, as demonstrated by tunel labeling, in about 10% of primary epithelial cells over 8 hr of exposure but 50% in the 9hteo - transformed cell line that lacks tight junctions ; treating another transformed cell line, 16hbe14o- that has high - quality tight junctions, with egta made them more susceptible to pao1-induced apoptosis. in contrast, stable transfection of a constitutively active variant of the regulatory r - domain of cftr did not alter rates of apoptosis elicited by pao1, nor did pao1 elicit significant apoptosis in cftr mice. these data suggest that the intrinsic loss of cftr is less important in epithelial cell survival than morphologic changes such as barrier integrity. this conclusion is challenged by a more recent study examining apoptosis after airborne particulate matter (pm) exposure in two epithelial cell lines, ib3 - 1 that contains compound heterozygote delta f508 and w1282x nonsense cftr mutations, and s9 that is derived from the ib3 - 1 cell line with the cf phenotype corrected by transfection with wild - type adenoassociated viral cftr. upon exposure to pm in a standard model for 1 hr, ib3 - 1 cells had a rate of apoptosis greater than six fold higher than that seen in s9 cells ; this was associated with disruption of mitochondrial polarity and activation of caspase-9 and blocked by overexpression of bcl - xl. increased susceptibility to oxidative stress may account for the effect of pm in this model, and oxidative - stress, a known inducer of apoptosis in other systems, may also have other effects that induce cell death in cf airway epithelium. ahmad and colleagues examined the expression and activity of sarcoendoplasmic reticulum calcium atpase (serca), a regulator of calcium homeostasis, in normal and cf epithelium and tissue. serca2 expression was decreased both in airway biopsies and in differentiated, polarized cultured epithelial cells from cf subjects and in cf epithelial cell lines, and expression of the 508-mutated cftr in cell lines led to decreased serca2 expression. serca2 displaces bcl-2 from the endoplasmic reticulum, and silencing of the serca2 gene enhanced epithelial cell death due to oxidative stress and to treatment with tnf-. pseudomonas infection may also provoke epithelial cell apoptosis by inducing the expression of cationic innate host defense peptides that injure the host. one such cationic peptide is ll-37, the predominant cleavage product of human cationic antimicrobial peptide (hcap)-18, the human cathelicidin (reviewed in). ll-37 is secreted by both neutrophils and epithelial cells and is upregulated in response to infection and inflammation [188, 189 ]. expressing ll-37 in murine lung enhances the clearance of pulmonary pseudomonas aeruginosa. ll-37 can induce apoptosis in both primary cells and in cell lines [191193 ] and does so via activation of the intrinsic pathway with release of cytochrome c and activation of caspase-9. interestingly, in the latter study, cell death required the presence of both the cationic protein and live bacteria, and either alone was incapable of inducing apoptosis. the effect of other cationic proteins such as the eosinophilic cations or that of synthetic cationic proteins such as polylysine have not been examined in the context of airway epithelial cell death. taken together, these studies show that epithelial cell apoptosis may be present in cf airways and that cf epithelial cells are perhaps more susceptible to apoptotic cell death following oxidant stress, bacterial infection, and perhaps to host defense factors (ll-37 as one demonstrated example). the relative contribution of apoptosis to epithelial damage in cf airways, as well as the contribution overall to cf pathophysiology, is yet to be defined. chronic obstructive pulmonary disease (copd) arises as a result of the inhalation of noxious stimuli to the lungs, most commonly cigarette smoke. damage to the central airways (chronic bronchitis) and to the peripheral lung (emphysema) commonly occurs. several mechanisms contribute to the pathogenesis of copd, including influx of inflammatory cells into the lung, disruption of the balance between proteolytic and antiproteolytic activity, and oxidative stress. some recent studies have suggested increased levels of apoptosis in peripheral lung endothelial cells [195, 196 ] and alveolar inflammatory cells [197, 198 ] (also reviewed in). it is surprising, given the levels of oxidative stress and the toxins inhaled in cigarette smoke, that apoptosis has not been investigated rigorously in central airway epithelial cells. examined markers of apoptosis in explant tissue obtained from a small cohort of patients with copd, idiopathic pulmonary fibrosis, or donated lung and demonstrated no evidence of such markers in copd. another study examined the presence of apoptosis in central airway epithelial cells collected by endobronchial brushing of 24 mm airways from 20 normal subjects and 23 subjects with copd. several assays to assess apoptosis were done to minimize the risk of technical artifact skewing the results. small airway epithelial cells collected by brushing from the patients with copd had increased labeling for the presence of apoptosis by each assay ; this was not affected by either the age of the subject or by smoking status. a recent study in which mice were exposed either acutely or chronically to ozone demonstrated that chronic exposure led to both central and peripheral airway epithelial cell apoptosis as measured by immunoreactivity to caspase-3 and the apoptosis protease activating factor-1 (apa-1). how apoptosis in the more central airways relates to the genesis of chronic bronchitis or airway inflammation is not yet known. peripheral alveolar epithelial cells in smoking subjects with copd also show evidence of apoptosis markers such as p53 or tunel [198, 204 ]. it is interesting to speculate that such cell death may contribute to the pathogenesis of emphysema, but no firm data has emerged. interstitial lung diseases comprise a spectrum of illnesses that have at their core fibrotic damage to the peripheral lung. one of these, idiopathic pulmonary fibrosis (ipf), is a progressive disease in humans that has, as central to its pathogenesis, injury to small airways and alveolar epithelial cells [205, 206 ]. over time continued injury and reaction to injury lead to impaired epithelial repair, phenotype shifting of fibroblasts to myofibroblasts, matrix deposition, and scarring. several types of injuring agents such as oxidative stress have been postulated as causes of the initial injury, even though antioxidant therapy has but modest benefit in these patients [208, 209 ]. apoptosis is clearly recognized in the alveolar epithelium in both human tissue samples of patients with ipf [210, 211 ] and in mouse models of lung fibrosis [212, 213 ]. increased expression of fas [214216 ] and of apoptosis signaling pathway intermediates such as p53 [210, 216, 217 ] are seen which may help explain the loss of epithelial cells. in contrast, damage to and apoptosis of more central airway epithelial cells are not seen. central airway epithelial cell apoptosis is not a prominent feature of other interstitial lung diseases, such as sarcoidosis or the collagen - vascular - associated lung diseases, as reported to date. lung transplantation (lt) remains the best hope for selected patients with end - stage lung diseases. chronic allograft rejection, clinically manifested as bronchiolitis obliterans syndrome (bos) and pathologically as obliterative bronchiolitis (ob), remains a major limitation to long - term survival : bos occurs in 4060% of lung transplant recipients within 4 years [218, 219 ] and is the leading cause of death after the first year [220, 221 ]. allograft rejection is mediated mainly by recipient alloreactive cd4 + and cd8 + effector t lymphocytes [222, 223 ] developed against mismatches in hla class i and ii antigens of the epithelial cells in the allograft [224226 ] ; these in turn may be suppressed by regulatory t suppressor lymphocytes that promote tolerance [227, 228 ]. an early study suggested that in transplanted lungs in which obliterative bronchiolitis was present, there were increased numbers of tunel - positive cells in large airway, small airway, and alveolar epithelial cells, whereas such labeling was virtually absent in transplant lung specimens that had no evidence for ob. an elegant study of ischemia reperfusion in the transplanted lung collected samples from peripheral donor lungs during cold ischemia, warm ischemia, or after graft reperfusion at the time of implantation. in this study, tunel labeling demonstrated significant alveolar but not more central epithelial cell apoptosis during the time of reperfusion but not during either ischemia periods. animal lung transplantation models provide important data concerning the role of apoptosis in obliterative bronchiolitis and in ischemia - reperfusion injury. increased numbers of apoptotic epithelial cells are seen prior to sloughing and obliterative bronchiolitis in the mouse heterotopic tracheal transplant model and in a similar model in swine, though the degree of apoptosis is modest compared to the subsequent loss of epithelial cells, suggesting that other processes such as necrosis or autophagy are as or more important. a more recent study examines epithelial cell apoptosis in an orthotopic mouse tracheal transplant model with preservation of ventilation through the transplanted airway. in this study, ventilation was permitted or occluded through the transplanted trachea, and morphometric and immunohistochemical measurements were made 28 days after transplant. epithelial cell morphology was better preserved in the ventilated group with more numerous ciliated cells, and tunel - labeling was substantially less in these allografts, ~12%, versus those that were not ventilated, ~66%. evidence for obliterative airways disease was present in the nonventilated allografts suggesting an association between ob and epithelial cell apoptosis. other studies suggest that airway obliteration characteristic of the heterotopic tracheal allograft model does not occur in orthotopic allografts and that recipient epithelial cells migrating into the donor graft may actually prevent obliteration [234236 ]. one intriguing study examined the role of treatment with an endothelin - a / b receptor antagonist, sb209670, to block apoptosis following ischemia - reperfusion injury in a dog model of lung allotransplantation. blocking the endothelin receptors led to lower numbers of apoptotic epithelial cells in the transplanted peripheral airways and alveoli as assessed by tunel labeling. one paper has examined epithelial cell apoptosis in a culture model using the kcc-266 cell line ; treatment with an antibody that activates class i hla responses (w6/32) elicits both proliferation and apoptosis over 48 to 72 hr. however, the cell line is not characterized or described in this study or elsewhere, and it is not clear whether this is a central or alveolar - derived cell. in addition to allergen exposure as noted above, various gasses and particles may elicit damage via initiation of apoptosis. one group of agents include the incompletely - combusted components of fossil fuels such as polycyclic aromatic hydrocarbons (pahs). one such family of hydrocarbons, benzo[a]pyrenees, can elicit apoptosis in primary small airway epithelial cells, but not the peripheral a549 adenocarcinoma epithelial cell line, in culture, by increasing free cytosolic calcium levels. fine particulate matter also can induce apoptosis in cf - derived epithelial cells as previously noted. another study of the effect of fine particulate matter (pm2.5) on the l132 human lung epithelial cell line demonstrated that exposure - induced apoptosis by both receptor - mediated (caspase-8 activation) and mitochondrial (cytochrome c release and caspase-9 activation) pathways. these fine particles are composed of a variety of inorganic and organic chemicals, including pahs, and it is not clear which part of the particle is responsible. to make this more complicated, another study demonstrated that a water - soluble fraction of pm2.5 actually inhibits apoptosis induced in three different epithelial cell lines and in primary epithelial cells ; the authors suggest that blocking apoptosis may contribute to prolonged inflammation and impaired repair in airways after pollution exposure. in support of this, rumelhard. examined the expression and role of egfr ligands such as amphiregulin, heparin - binding epidermal growth factor - like growth factor (hb - egf), and tgf- in primary airway epithelial cells and the 16hbe14o- cell line after exposure to pm2.5. secretion of each ligand was seen, and each elicited expression of cytokines such as granulocyte - macrophage colony stimulating factor (gm - csf). this study was subsequently replicated in primary airway epithelial cells using pm2.5 with different pah and metal contents, demonstrating significant overlap between the groups suggesting that the exact composition of the particulate matter is less important. clearly, the effect of environmental agents on epithelial cell apoptosis, as well as the subsequent effect upon airway homeostasis, requires further investigation. one interesting paper notes the effect of mechlorethamine, a functional analogue of vesicant sulfur mustard used in chemical warfare, on differentiated hbe1 cells in culture. in this model, mechlorethamine treatment elicited epithelial layer disruption with evidence of both cytotoxic and apoptotic changes in a concentration and time - dependent manner. in contrast to inflammatory cells which undergo apoptosis readily and quickly after an appropriate stimulus, epithelial cells have some innate resistance to similar provocation. understanding this relative resistance to cell death may hold a vital clue for understanding the role of apoptosis in airway homeostasis and may also have important implications for diseases that are epithelial based but not touched on in this paper, such as lung cancer. while this paper has not considered the roles of necrosis and autophagy in epithelial cell death, the former especially may be as, or more, important in selected airway conditions. nevertheless, apoptosis clearly is involved in epithelial cell death in several inflammatory airways diseases. there is regional variation in the response to apoptotic stimuli : when directly assessed, small airways (bronchiolar) epithelial cells are more sensitive than those collected from larger bronchi or trachea. there is significant variation in the response to activation of death receptors and in receptor - mediated versus stress - activated (via mitochondrial polarity disruption) apoptosis. finally, apoptosis is required to return an inflamed airway, or one that is hyperplastic or metaplastic, to normalcy. recognizing when and how apoptosis is important to airway inflammation and how to turn that process to our advantage offers potential therapeutic targets for several airways diseases. | the airway epithelium functions as a barrier and front line of host defense in the lung. apoptosis or programmed cell death can be elicited in the epithelium as a response to viral infection, exposure to allergen or to environmental toxins, or to drugs. while apoptosis can be induced via activation of death receptors on the cell surface or by disruption of mitochondrial polarity, epithelial cells compared to inflammatory cells are more resistant to apoptotic stimuli. this paper focuses on the response of airway epithelium to apoptosis in the normal state, apoptosis as a potential regulator of the number and types of epithelial cells in the airway, and the contribution of epithelial cell apoptosis in important airways diseases. |
conjunctivitis is the inflammation of the conjunctiva and has 4 main causes - viruses, bacteria, allergens, and irritants. of these, the acute infective causes (viruses and bacteria) are the most frequently encountered ocular disorders in primary care. the most prominent symptoms of acute infective conjunctivitis include mild pruritus, foreign body sensation, and mild photophobia. the most prominent signs include crusted eyelids that are often matted shut, especially after sleep, generalized conjunctival infection, and either watery or purulent discharge from one or both eyes, but no loss of visual acuity. among eye infections, herpetic keratitis is one of the worst that can be contracted by clinical dental staff, but bacterial conjunctivitis caused by staphylococcus aureus is more common. other conjunctival pathogens such as chlamydia trachomatis have been reported, although rarely, to have been transmitted in dental practice. dental hygienists and dentists had a higher incidence of conjunctivitis than dental technicians and dental assistants. so enough knowledge and awareness of conjunctivitis is necessary for prevention and spread of conjunctivitis in dental clinics. at a normal working distance, there is no zone of safety from organism bearing droplets and bacteria may remain in suspension in the air for up to 30 min. there is a risk that the protective mechanisms of the eye may be overwhelmed by such high concentrations of pathogen. hence, the present study was undertaken to assess the knowledge and awareness regarding eye flu among the dentists and dental auxiliaries of udaipur city, rajasthan, india. a pretested questionnaire survey was conducted among 152 subjects (those who were present at the time of survey) aged 18 to 60 years of udaipur city, rajasthan in march 2012. the respective concerned authorities were approached and explained the nature of the study and permission was obtained. written informed consent was obtained from study participants. single trained interviewer described the purpose and process of the survey to the participants and gave standardized instructions for completing the questionnaire. kappa (k), weighted kappa (kw) were used to evaluate the test - retest reliability of the questionnaire and internal consistency was assessed by cronbach 's alpha () coefficients (k = 0.86), (kw = 0.9), (= 0.78). the questionnaire proforma comprised of demographic data like name, age, sex, education, employment and questions regarding previous eye flu infection, causes of conjunctivitis, signs and symptoms, spread of diseases and dental treatment with eye flu infected person. the script was presented both in english and hindi for easy understanding and convenience of the study participants. all (80 dentists and 72 dental auxiliaries) the subjects (mean age 28.40 6.38 years) returned the questionnaire. out of total participants, majority of 106 (69.74%) were male and 46 (30.26%) were female. regarding the education of staff members, majority 74 (48.68%) were graduate and only 6 (3.95%) was illiterate [table 1 ]. demographic characteristics of the participating dentists and dental auxiliaries when asked about the previous experience of eye flu, 67 (44.08%) participants reported that they had been infected with eye flu previously. regarding the causes of conjunctivitis, majority of 123 (80.92%) of participants agreed that virus or bacteria caused eye flu [table 2 ]. causes of conjunctivitis as reported by the dental professionals majority of 145 (95.39%) of the participations agreed that eye turned red during eye flu [table 3 ]. dental professional 's knowledge regarding signs and symptoms of conjunctivitis majority of study participants 123 (80.92%) replied that the dental treatment should be delayed for a patient infected with eye flu till the symptoms subside. to our knowledge this is the first study to explore knowledge and awareness of eye flu among the dentists and dental auxiliaries. the results in the study were reasonably reliable and can be generalized. in the present study, 67 (44.08%) reported that they had been infected with eye flu previously while in the study done among 204 dental person in riyadh, saudi arabia, 73 (35.78%) study subjects and 42.9% dentists had been infected with eye flu. in the present study, 145 (95.39%) subjects had reported that redness of eye was the clinical feature of eye flu while 211 subjects out of 232 had reported that eye turned red in eye flu. doctors, parents have differing perspectives and agendas for the management of this condition. factors that influence the decision include beliefs about the condition and the need for treatment, patient 's own time, economic considerations and public health policy. in the present study, 123 (80.92%) in hampshire, uk, 134 out of 229 general practitioners used past history of contact with infected person for diagnosis of conjunctivitis. bacteria or viruses can get in your eyes through contact with contaminated objects, including hands, washcloths or towels, cosmetics, false eyelashes and soft contact lenses. proper hand and eye hygiene is necessary for prevention and treatment of eye flu as there is a high spontaneous remission rate for bacterial conjunctivitis. if there is no improvement after 2 - 3 days of conservative management of eye flu, ophthalmic antibiotics should be prescribed. limited evidence suggests that bacterial conjunctivitis is self limiting, with 64% of cases resolving in 2 to 5 days without treatment, topical antibiotics are prescribed in an attempt to shorten the illness, reduce complications and re - infection. education regarding the self - limiting nature of the condition and the minimal need for antibiotics is important for changing the management expectations of parents, schools, and day cares. written materials, such as pamphlets, are safe and cost - effective way of facilitating such education, with high rates of patient satisfaction and compliance. eye flu being an occupational hazard among dentists, personal ophthalmic prophylactic care is a must which helps in prevention of spread of infection to other patients and family members. | background : conjunctivitis is the inflammation of the conjunctiva and has 4 main causes - viruses, bacteria, allergens, and irritants. among these, bacterial conjunctivitis is most common and is contagious, especially when the dentist is working with the infected person, and that person spreads the same to the other patient.methods:a pretested questionnaire survey was conducted among 152 subjects (those who were present at the time of survey) aged 18 to 60 years of udaipur city, rajasthan in march 2012. ethical clearance was obtained from relevant authority. written informed consent was obtained from study participants.results:all (80 dentists and 72 dental auxiliaries) the subjects returned the questionnaire. regarding previous experience of eye flu, 67 (44.08%) participants reported that they had been infected with eye flu previously. majority 123 (80.92%) of participants agreed that virus or bacteria caused eye flu. majority of 145 (95.39%) of the participants agreed that the eye turns red during eye flu. one hundred and twenty three (80.92%) subjects replied that the dental treatment for a patient infected with eye flu should be delayed till the symptoms subside.conclusions:eye flu being an occupational hazard among dentists, personal ophthalmic prophylactic care is a must which helps in prevention of spread of infection to other patients and family members. |
catheter ablation is a procedure used to treat some types of arrhythmia, when drug therapies are not effective. one type of arrhythmia that is usually treated with this procedure is ventricular tachycardia (vt) associated with ischemic cardiomyopathy (ic). after a myocardial infarction, myocardial cells die because of the lack of oxygen supply, creating fibrotic areas where electrical impulses are not propagated. around and through these areas of dense fibrosis, other areas with low - density fibrosis where the impulse is propagated with a low velocity appear. sometimes, these areas of slow conduction represent corridors with at least two connections with healthy muscle, being the substrate for reentrant vts. these slow conduction corridors or conducting channels are the target for vt ablation,. different information sources have been used during the last years to identify the conducting channels that are responsible for reentrant vts. delayed enhancement magnetic resonance imaging (de - mri) is used to find the ablation target prior to the intervention, while electro - anatomical mapping (eam) systems are used intra - operatively. in clinical practice, these two information sources are used separately to characterize cardiac tissue based on different properties. in this paper, a new framework that allows the integration of images from de - mri, electrical measurements and mechanical properties estimated using an eam system recently, many approaches have been developed to characterize scar tissue from different information sources. in this section, a short review of methods for scar characterization from de - mri, electrical and mechanical information obtained from eam systems is presented. de - mri has become the standard modality to localize and quantify areas of scar, viable and healthy myocardial tissue pre - operatively. the acquired images visualize the uptake of a contrast agent by the intracellular space after a given time from the administration of the contrast. healthy myocardium and scar tissue have different uptake profiles and hence, are imaged differently (fibrotic areas appear brighter than healthy myocardium). de - mri could be used for ablation planning by identifying pre - operatively the target ablation areas during the procedure. however, the inherent limitations of mri leading to imaging artifacts can lead to errors when identifying scar tissue,. in addition, the spatial resolution limits the detection of the border zone channels in the dense scar tissue, since these channels can be very narrow,. different segmentation methods from de - mri have been proposed during recent years. having the segmentation of the myocardium, the scar can be localized based on voxel intensities, since it appears significantly brighter than healthy myocardium. to recover the anatomical structure of the scar other approaches imposing geometrical constraints have been presented to improve the consistency of the results,. when the catheter is properly positioned, it allows the electrical activity at its tip to be recorded ; then, based on the tracked position of the catheter tip, the system shows a spatial reconstruction of the mapped cavity, also providing the electrical signals recorded. it is also possible to use an additional software module that allows pre - operative images to be integrated for a better visualization and interpretation of the acquired information. during the intervention, it is necessary to accurately locate and characterize the scar tissue to find the conducting channels responsible for the vt, which are the ablation target. after the acquisition, different electrical parameters are used to identify the ablation target, such as the maximum bipolar and unipolar voltages, and the local activation time. scar core, border zone and healthy tissue can be classified using voltage thresholds. however, there are no standard thresholds that can be used for all patients, which makes the cardiologist s expertise a key factor in a successful intervention. in addition, data obtained from eam systems have several limitations for a precise characterization of the arrhythmogenic substrate (i.e. far - field effect, time - consuming, poor tissue contact). other types of information, such as myocardial mechanics, can also be considered to better characterize the scar and, therefore, to improve the result of the ablation procedure. it is possible to assess cardiac mechanics during the intervention by using catheter tracking information to estimate cardiac contractility,. noga (biologics delivery systems group, cordis corporation, irwindale ca, usa) was developed to estimate cardiac mechanics for tissue viability assessment. a technique to integrate electrical and motion information was described in as part of this system and different clinical applications were proposed in. in, a methodology to estimate 3d endocardial motion and deformation fields from electro - anatomical data and a pre - operative image was proposed. the limitations of the aforementioned methods are related to the accuracy of the catheter tracking system and the presence of components in the recorded motion signals that are not directly related to cardiac motion (i.e. motion related to respiration). even though scar tissue can be characterized from different information sources, all of them have some limitations. in addition, the results obtained from different sources are based on different tissue properties, so the shape and extent of the scar identified using each modality is not necessarily the same,,. the information from the different sources could be considered together for a better characterization of myocardial tissue. in and, a correlation between the conducting channels inside the scar detected by de - mri and eam systems was found. in, it was shown that integrating electrical and mechanical information provided better results than using each type of information separately. however, to the best of our knowledge, there are no known tools that allow the integration of the information from de - mri with electrical and mechanical properties of the heart. in this paper, a framework is presented where these three sources of information are integrated for multimodal left - ventricular myocardial tissue characterization. the presented framework has a modular design, integrating three different modules to support the process of scar characterization : cardiac segmentation, image - based characterization and electrical / mechanical characterization from the data recorded with an eam system. these modules were integrated in gimias (www.gimias.org), which is a workflow - oriented open - source environment that can be extended through the development of problem - specific plug - ins. each of the modules for scar characterization is located at the plugin layer and can be used independently of the others. meshes, images, signals or any type of information are attached to the main data tree and are directly accessible by any other module. 1 (b) shows a schematic describing how the presented modules inter - operate. in the following sections, each of the modules for scar characterization will be presented the plugin layer is on the top and plugins can interoperate through the elements at the framework layer. the third party layer is at the bottom, to which all modules have access. both endocardium and epicardium meshes are segmented from de - mri using the cardiac segmentation module. the output meshes are used by the image - based characterization module to characterize the scar based on voxel intensities. the segmented endocardium is also used, together with electro - anatomical mapping data, for electrical and mechanical characterization of the left ventricle. the plugin layer is on the top and plugins can interoperate through the elements at the framework layer. the third party layer is at the bottom, to which all modules have access. both endocardium and epicardium meshes are segmented from de - mri using the cardiac segmentation module. the output meshes are used by the image - based characterization module to characterize the scar based on voxel intensities. the segmented endocardium is also used, together with electro - anatomical mapping data, for electrical and mechanical characterization of the left ventricle. the cardiac segmentation module provides algorithms for a semi - automatic segmentation of 3d+t images of the heart from different modalities. the underlying methodology is the same for all modalities, which brings a great advantage when integrating multiple sources of image data. the method uses a deformable model that encodes statistical information about the shape of the heart based on a point distribution model (pdm). the pdm was built from 134 patients in 15 cardiac phases, totaling 2010 training volumes,. the segmentation algorithm has been trained and evaluated on ct, spect, 3d us and mri datasets. to segment the left ventricle, the user sets three landmarks in the images : one at the center of the aortic valve, one at the center of the mitral valve and another one at the apex. the software positions and scales the average shape in the pdm based on these three landmarks. this pdm contains both the endocardium and the epicardium, and acts as a template that is adapted to the geometry of each patient s heart. manual corrections can be performed to fix possible errors in the results from the automatic processing. these corrections can be applied either freely or by imposing statistical constraints. the second module in the pipeline it needs the model of the left ventricle to be segmented using the cardiac segmentation module as an input. this module divides the segmented ventricle into a number of layers that can be selected by the user from the endocardium to the epicardium, obtaining a 3d shell for each of the layers. one signal intensity map at each layer is obtained by summing the intensity of all the voxels between neighboring layers, as explained in. scar areas can be differentiated from healthy myocardium based on the distribution of the intensities in the image, since scar tissue appears brighter in de - mri. moreover, scar core and border zone can also be identified using thresholds, as previously reported in. based on this study, areas with signal intensities higher than 60% of the maximum are classified as scar core, while areas with signal intensities lower than 40% of the maximum are classified as healthy tissue. the remainder of the tissue is considered as border zone. however, since image artifacts may affect the intensity range in the image, these thresholds may need to be adjusted manually. finally, this threshold - based classification can be visualized in 3d through color - coded maps in every transmural shell. 2 shows one example of segmentation of a left ventricle with scar tissue characterized based on image intensity levels using the presented framework. red represents dense scar tissue, green represents viable tissue (border zone) and purple represents healthy myocardium. red represents dense scar tissue, green represents viable tissue (border zone) and purple represents healthy myocardium. the third module in the pipeline allows both electrical and mechanical characterization of the tissue using eam data and a left ventricle model segmented using the cardiac segmentation module. this module allows electro - anatomical data to be loaded and used intra - operatively in a catheter - guided intervention. it is possible to visualize all the electrical signals recorded, together with the catheter tracking information. the maximum bipolar voltage, maximum unipolar voltage and local activation time at each point are calculated for electrical characterization of the tissue. the trajectory of the catheter (which is in contact with the endocardium) during the acquisition of the local electrograms can also be visualized (see fig. purple color represents healthy tissue (> 1.5mv) and red color represents dense scar (1.5mv) and red color represents dense scar (< 0.5mv). the information is also represented using the 17-segments model proposed by the american heart association. bipolar, unipolar electrograms and superficial ecg (lead i) are also shown in the upper left corner for one selected point. the cloud of points acquired during the intervention can be registered to the endocardial surface extracted from the cardiac segmentation module. this is done by selecting at least three landmarks in both the surface and the cloud of points. then, an iterative closest point (icp) algorithm can be used to improve the registration results. if ventricle segmentation is used intra - operatively to guide the intervention, it is also possible to load the transformation matrix calculated intra - operatively, getting the same registration used during the intervention. after registration, all the electrical parameters on the endocardial surface can be projected and interpolated. they can also be projected into any of the different layers with scar information obtained from de - mri, allowing the visualization of the information from both sources on the same surface. once the ventricle shape and the points from the eam system are registered, it is also possible to estimate endocardial motion and deformation using the method presented in. this method extracts the catheter trajectories during one cardiac cycle and synchronizes the motion signals of all the points acquired. then, catheter trajectories are projected into the endocardial mesh using a bilinear atlas to help interpolate motion in the areas where this information is not available. the result is a 3d+t endocardial mesh where both displacement field and directional strains are also calculated, providing mechanical information at each time point. finally, all the information can be visualized into the 17-segments model proposed by the american heart association (aha). curves showing the evolution of displacement and strain can also be obtained and exported. as an illustration, fig. 3 shows a cloud of eam points registered to a left ventricle segmentation, together with the electrical scar characterization. all patients included in the study underwent a de - mri exam prior to the ablation procedure (median 2 days, interquartile range 16 days). a 3-tesla scanner (magnetom trio, siemens medical solutions, erlangen, germany) equipped with advanced cardiac - dedicated software and a cardiac 12-element phased array coil was used. seven minutes after intravenous administration of gadodiamide - dtpa (omniscan, amersham health) at a dose of 0.2 mmol / kg, a whole - heart, high spatial resolution, de - mri study was conducted using a free - breathing, navigator - gated, 3d inversion - recovery, gradient echo technique. the field of view (fov) was set to 360 mm and matrix size was kept at \documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } \(256 \times 256\) \end{document } pixels to yield an isotropic spatial resolution of \documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } \(1.4 \times 1.4 \times 1.4\) \end{document } mm. a standard delayed - enhanced dataset was obtained by applying a 2d ir - turboflash sequence in sequential 5 mm slices with no gap between them, to cover both ventricles in the short - axis orientation in addition to the 2-, 3-, and 4-chamber views. trans - septal or retro - aortic approaches were used for left ventricular access. an endocardial high - density 3d electro - anatomical bipolar voltage map of the left ventricle was obtained during stable sinus rhythm using the carto system. standard voltage thresholds (< 0.5 mv for the core and < 1.5 mv for the border zone) were used to define the scar on the eam. the conducting channels on the eam were visually identified as : (i) corridors of border zone (maximum bipolar voltage between 0.5 and 1.5 mv) within scar core areas or between a scar core area and the mitral annulus, or (ii) late potential channels. the latter were defined as regions with 2 or more consecutive endocardial electrograms presenting delayed components, localized in the scar area and connecting with healthy tissue, which are not possible to visualize using voltage thresholds. results from three patients are presented to illustrate the framework s utility for catheter ablation planning and treatment. for these three cases, the left ventricle was segmented from de - mri prior to the catheter ablation intervention using the cardiac segmentation module. then, the module for image - based scar characterization was used to classify the scar core, border zone and healthy myocardium. the meshes obtained pre - operatively were used during the intervention to guide the procedure. the electro - anatomical maps obtained were then imported into the module for electrical and mechanical characterization from eam data. finally, electrical values were projected into the endocardial mesh and ventricular motion was reconstructed. for each patient, a figure including different measurements obtained by integrating data with the presented framework is shown : segmentation of the left ventricle and scar characterization from de - mri, maximum unipolar voltage, maximum bipolar voltage, local activation time recorded with carto and projected onto the ventricle shape, and longitudinal strain estimated at end systole as presented in. in addition, a comparison between the extension of the scar identified pre - operatively from de - mri and intra - operatively using the bipolar maps was also performed. the first patient analyzed for this study was a 75 year old man with vt associated with ic. 4 shows the results for this patient. in this case, a scar was identified pre - operatively from de - mri in the inferior wall of the left ventricle. after the electrophysiology study, the maximum bipolar voltage showed a very homogeneous scar in comparison with the scar shape obtained from de - mri. the scar area defined using the bipolar voltage map was 39% larger compared to the scar identified from de - mri, while the border zone area was 11% smaller. figure 4.information integrated by the framework for a 75-year - old man with vt associated with ic. in the scar characterization from de - mri, red color represents scar core, purple represents healthy tissue and the rest of the colors represent border zones according to the signal intensity maps. the electrical information is represented by the bipolar voltage map, the unipolar voltage map and the local activation time map. longitudinal strain calculated at end end - systolic strain values are represented on the endocardium at end - diastolic phase to improve visual comparison with the other results. information integrated by the framework for a 75-year - old man with vt associated with ic. in the scar characterization from de - mri, red color represents scar core, purple represents healthy tissue and the rest of the colors represent border zones according to the signal intensity maps. the electrical information is represented by the bipolar voltage map, the unipolar voltage map and the local activation time map. longitudinal strain calculated at end systole is shown, where negative values represent contraction and positive values indicate stretching. end - systolic strain values are represented on the endocardium at end - diastolic phase to improve visual comparison with the other results. the maximum unipolar voltage map showed a shape and extension of the scar very similar to the one from the maximum bipolar map. the local activation time showed a conduction delay in the areas around the dense scar, where electrical impulse was still propagated. as expected, spatially heterogeneous strain patterns were obtained. in particular, the longitudinal strain showed no contraction or stretching in the dense scar area while it reflected contraction in the surrounding areas. ablation was performed at the entrance of each one of the conducting channels identified pre - operatively from de - mri, resulting in a non - inducible arrhythmia and hence, a successful intervention. the results for another patient (male, aged 69, vt with ic) are shown in fig. the de - mri study showed an infero - septal scar with a wide longitudinal line of border zone tissue. the extension of the scar identified with the bipolar map was 23% larger than the one identified from de - mri. in this case, the bipolar map showed low voltage values for the whole base of the ventricle, while the scar defined from de - mri was only localized in the inferior wall. the border zone area from the bipolar map was 65% larger compared to results from de - mri, finding reduced voltage values in a large area of the ventricle. figure 5.information integrated by the framework for a 69-year - old man with vt associated to ic. in the scar characterization from de - mri, red color represents scar core, purple represents healthy tissue and the rest of the colors represent border zone according to the signal intensity maps. the electrical information is represented by the bipolar voltage map, the unipolar voltage map and the local activation time map. longitudinal strain calculated at end end - systolic strain values are represented on the endocardium at end - diastolic phase to improve visual comparison with the other results. red spheres represent the ablation targets identified pre - operatively from de - mri, while grey speheres represent the ones identified intra - operatively using the electrical maps. information integrated by the framework for a 69-year - old man with vt associated to ic. in the scar characterization from de - mri, red color represents scar core, purple represents healthy tissue and the rest of the colors represent border zone according to the signal intensity maps. the electrical information is represented by the bipolar voltage map, the unipolar voltage map and the local activation time map. longitudinal strain calculated at end systole is shown, where negative values represent contraction and positive values indicate stretching. end - systolic strain values are represented on the endocardium at end - diastolic phase to improve visual comparison with the other results. red spheres represent the ablation targets identified pre - operatively from de - mri, while grey speheres represent the ones identified intra - operatively using the electrical maps. the unipolar map showed low voltages for the whole scar, being higher at the entrance of the line of border zone tissue identified from de - mri. the local activation time presented some heterogeneities at the entrance of this border zone line, as in the case of the unipolar voltage map. the longitudinal strain showed reduced contraction in the inferior wall, with higher contraction at the entrance of the border zone channel identified from de - mri. it is also possible to observe the presence of stretching areas in the dense scar area. the points of ablation were situated at the entrance of the corridor of border zone that was identified from both de - mri and the electrical maps. 6 shows the results for the third patient (male, aged 82, vt with ic). the de - mri study allowed the identification of a scar in the anterior wall. the bipolar map showed a dense scar area 57% larger than the area identified from de - mri. on the other hand, the area of border zone tissue was 33% smaller compared to the results de - mri. figure 6.information integrated by the framework for a 82-year - old man with vt associated to ic. in the scar characterization from de - mri, red color represents scar core, purple represents healthy tissue and the rest of the colors represent border zone according to the signal intensity maps. the electrical information is represented by the bipolar voltage map, the unipolar voltage map and the local activation time map. longitudinal strain calculated at end systole is shown, where negative values represent contraction and positive values indicate stretching. end - systolic strain values are represented on the endocardium at end - diastolic phase to improve visual comparison with the other results. red spheres represent the ablation targets identified pre - operatively from de - mri, while grey speheres represent the ones identified intra - operatively using the electrical maps. information integrated by the framework for a 82-year - old man with vt associated to ic. in the scar characterization from de - mri, red color represents scar core, purple represents healthy tissue and the rest of the colors represent border zone according to the signal intensity maps. the electrical information is represented by the bipolar voltage map, the unipolar voltage map and the local activation time map. longitudinal strain calculated at end end - systolic strain values are represented on the endocardium at end - diastolic phase to improve visual comparison with the other results. red spheres represent the ablation targets identified pre - operatively from de - mri, while grey speheres represent the ones identified intra - operatively using the electrical maps. the longitudinal strain was reduced in the whole wall, showing some stretching in the apex. in this case, ablation was performed at the border zone channels identified from de - mri and the local activation time map, as seen from fig. three study cases were presented, showing multimodal myocardial tissue characterization based on different information sources. results demonstrated the clinical feasibility of the approach and showed that there is a relation between the shape and extension of the scar identified from the different sources. however, as expected, there are also variations between the results from the different modalities. in the three cases presented, the extension of the dense scar area identified using electrical maps was larger than the dense scar area identified from de - mri (range 23%57%). it was possible to identify most of the conducting channels prior to the intervention from de - mri, although the electrical maps were necessary to find all of them, as it can be observed from fig. maximum bipolar and unipolar voltage maps showed a similar shape and extension of the scar. in the case of the second patient, the unipolar voltage map showed areas with low voltage values that were not identified by the bipolar voltage map. these differences could be explained because endocardial bipolar maps give information about subendocardial activation, while endocardial unipolar voltage maps give transmural information. the local activation time map was able to detect the conducting channels for the three patients presented, showing delayed activation in comparison to the healthy myocardium. unipolar and bipolar maps were not able to distinguish all conducting channels, showing a homogeneous scar core. activation maps during sinus rhythm have been recently proposed to better define the areas of interest during substrate mapping as areas with ventricular activation after the qrs,. for the cases analyzed, stretching areas at end systole were found in the scar core, with contraction around these areas. heterogeneities in the scar areas could be explained by the tethering to adjacent tissue, being the contraction or stretching due to passive motion. moreover, the presence of scar tissue affects the motion of the whole ventricle and thereby its deformation. the example cases presented showed that the proposed framework is feasible and potentially useful for the analysis and integration of multi - modal information for scar characterization. it could be used intra - operatively for guidance and monitoring of therapy by integrating it with any eam system. they do not constitute, however, a detailed quantitative validation on the clinical impact of this technique (e.g. in terms of reduction of interventional time or x - ray radiation dose). a prospective study of clinical impact that includes a randomized population of subjects suffering from vt and undergoing radiofrequency ablation using this technique and the standard - of - practice is the natural next step. this work does, however, offer, as a first step, the preliminary proof - of - concept evidence for such a study. furthermore, the presented framework also allows annotating both the electrical signals and the visualized meshes. in addition, all the information used can be exported for subsequent analysis or for research purposes. one limitation of this framework is that motion and deformation were only estimated for the endocardium of the left ventricle. the reason is that the spatiotemporal atlas used only includes shape and motion information about the endocardium of the left ventricle. this framework could be extended in multiple ways (including algorithms for predictive analysis, automatic detection of conducting channels\documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } \(\ldots \) \end{document }) a framework for the integrated analysis of de - mri, electrical and mechanical information has been presented. integrating multi - modal information can be helpful for interventional guidance and monitoring of radiofrequency ablation procedures where myocardial scar tissue characterization is required. the three presented example cases show that the relevance of the information extracted from the different sources can vary depending on the patient analyzed (i.e. conducting channels that are visible in de - mri but not in the bipolar and unipolar maps and vice versa). the framework can also be helpful for research purposes, facilitating the study of the relation between electrical and mechanical properties of the tissue, as well as the information obtained from de - mri. | merging multimodal information about myocardial scar tissue can help electrophysiologists to find the most appropriate target during catheter ablation of ventricular arrhythmias. a framework is presented to analyze and combine information from delayed enhancement magnetic resonance imaging (de - mri) and electro - anatomical mapping data. using this information, electrical, mechanical, and image - based characterization of the myocardium are performed. the presented framework allows the left ventricle to be segmented by de - mri and the scar to be characterized prior to the intervention based on image information. it allows the electro - anatomical maps obtained during the intervention from a navigation system to be merged together with the anatomy and scar information extracted from de - mri. it also allows for the estimation of endocardial motion and deformation to assess cardiac mechanics. therefore, electrical, mechanical, and image - based characterization of the myocardium can be performed. the feasibility of this approach was demonstrated on three patients with ventricular tachycardia associated to ischemic cardiomyopathy by integrating images from de - mri and electro - anatomical maps data in a common framework for intraoperative myocardial tissue characterization. the proposed framework has the potential to guide and monitor delivery of radio frequency ablation of ventricular tachycardia. it is also helpful for research purposes, facilitating the study of the relationship between electrical and mechanical properties of the tissue, as well as with tissue viability from de - mri. |
the tradeoffs required to finance health care spending have become increasingly challenging for both private and public payers. in the private market, the rate of this spending growth may limit the enrollment, breadth, and depth of health care coverage, and in the government budget process, the rapid pace poses both short- and long - term financing challenges as mandatory spending grows faster than discretionary spending. in this article, we compare the incremental or marginal increase in u.s. health spending to that of gdp, federal outlays, and state and local government expenditures. when viewed relative to the constraints in financial resources, these incremental changes in health spending provide a better understanding of the implications of decisions made by our nation 's health policymakers and financers of health care. for almost all of the past 40 years, growth in health care spending has outpaced economic growth. for the public sector, this increased spending has meant more government health coverage for a variety of populations, including people with low incomes, the working poor and their children, the elderly, and the disabled. in 1960, spending on public programs accounted for 25 percent of national health expenditures (nhe), but reached 45 percent of health expenditures by 2004 (centers for medicare & medicaid services, 2006). within the private sector, the breadth of private health insurance coverage grew as consumer out - of - pocket spending declined, while health insurance premiums outpaced wage growth. consequently, the health spending share of gdp more than tripled between 1960 and 2004, as it rose from 5.2 to 16.0 percent of gdp. cms is projecting health spending to absorb an even higher share of gdp over the next decade, likely influencing the ability of governments to pay for education, defense, transportation, and other vital services. because resources are limited, the growth in health spending can elicit tradeoffs that are often difficult to conclusively track. of particular concern is the increase in the health spending share of economic growth and of government outlays. for instance, health care spending absorbed well over one - half of the nominal increase in federal government outlays in 1993 and 27 percent of the nominal increase in the economy over the 2000 - 2004 period. federal and state governments face increasing demands in providing care for low - income, elderly, and disabled individuals and will encounter even more in future years as the baby boom generation retires. in the medicare program, the large increase in the number of beneficiaries and in per - beneficiary spending is expected to propel spending growth even faster, while current growth already outpaces that of the federal budget. furthermore, an increasing proportion of total medicare spending is expected to be financed through general government revenues, and as this occurs, the challenges of paying for medicare and other programs will become more explicit (board of trustees, 2006). concern over this has prompted a proposal in the 2007 presidential budget that allows for an across - the - board 0.4 percent cut to medicare spending if general revenue funding reaches 45 percent of total funding (u.s. office of management and budget, 2006a). if promised benefits are paid, challenging consequences such as a higher budget deficit or increased taxes may result (penner, 1999). alan greenspan recently told lawmakers that the federal budget is on an unsustainable path and suggested that changes in social security retirement and medicare benefits be made sooner rather than later (andrews, 2005). the average health spending share of gdp is frequently cited as a measure of the ability and willingness of society to purchase health care. while the average share yields information about the magnitude of health spending in relationship to gdp, it does not indicate whether health spending increased its share of total spending relative to all other spending in a given year. one way to provide some insight into this question would be to compare, for each year, the incremental increase in health spending to that year 's additional resources available to pay for it. an increase in the incremental, or marginal, share of spending for health occurs when there is faster relative growth in health spending (the numerator) or slower relative growth in the resource constraint (the denominator) (kowalczyk, freeland, and levit, 1988). the analysis in this article is based on nominal values for health expenditures developed within the cms nhe accounting framework, nominal gdp, and nominal federal government outlays (bureau of economic analysis, 2006). additional elaboration and caveats regarding the estimates in this article are available on the internet at http://www.cms.hhs.gov/nationalhealthexpenddata/ or by request from the authors. as health spending grows faster than gdp in most years (table 1), health spending is higher at the margin than health spending as a share of gdp on average. this higher marginal relationship drives up the average share over time ; from 5.2 percent in 1960 to 16 percent in 2004. admittedly, if society were n't willing to change its preferences and health spending continued to grow significantly faster than gdp during expansionary periods, health expenditures could eventually consume almost all of the real marginal growth in a given year. to be sure, welfare can rise even if income less health care falls, because the benefits resulting from increased spending for health care can outweigh the losses in reduced consumption of other goods (johnson and penner, 2004). potentially, it may be sustainable to devote an increasing marginal share of gdp to health care as long as real spending on non - health services is preserved (chernew, hirth, and cutler, 2003). the marginal share during the 1970 - 1980 period (10.3 percent) foreshadowed an increase in the average health share of gdp, which surpassed the 10.3 percent threshold by 1983 (table 1). in the 1980 - 1990 period, the marginal share for health was 15.3 percent, a precursor of the average share reaching this level by 2002, despite policy changes that delayed this outcome. the most recent marginal share of 27 percent incurred in the 2000 - 2004 period indicates that health care may eventually reach a much higher average share of gdp. under cms current law projections, health care is expected to increase to 20 percent of gdp by 2015 (borger. we also find that a larger share of the increase in gdp is spent on health during recessionary periods (figure 1). to some extent, the countercyclical nature of health spending is beneficial in that it helps to cushion the impact of cyclical swings in gdp. for example, medicaid spending often increases during recessionary periods as the unemployment rate rises. a sharply rising marginal share often reflects the effect of a contraction in real gdp, and the effect becomes more significant as the average share of health to gdp increases. the relative severity of economic downturns has a significant impact on the magnitude of the spike in the marginal share. the recession of 1980 - 1982 was more severe than the 1990 - 1991 and 2000 - 2001 recessions. in 1982, health spending absorbed a much higher marginal share of gdp, at 29 percent, than had yet been experienced. as the pace of health spending in the 1980s grew rapidly and pressures to constrain growth were building, the economic contraction of 1990 - 1991 exacerbated the growing pressure from the health sector, with health spending absorbing 35 percent of nominal economic growth in 1991. employers responded to this situation by encouraging employees to enroll in managed care plans, whose enrollment captured 54 percent of all insured workers in 1993 and 86 percent of those workers by 1998 (levitt., 1999). enrollment in federal government - sponsored managed care plans also began to pick up in the 1990s. the most recent spike in the marginal share of gdp surpasses the levels shown for earlier periods. the marginal share reached 37 percent in the 2001 recession, which occurred simultaneously with the granting of supplemental funding to medicare providers and the reaching of the peak of the backlash against restrictive managed care arrangements. it is interesting to consider how much of the increase in the marginal share could be attributed to the period 's weakening economy, as opposed to the rising rate of health spending. that is, what would the health spending share of gdp growth have been if the economy, rather than contracting, had expanded at its average rate for the period ? what would the share have been during 2000 - 2001, when the recession was admittedly mild compared with the prior two recessions ? to simulate this, we redistributed the nominal economic growth that took place as the economy contracted then rebounded from each downturn. we then compared the data series that reflects the growth in marginal share during recessions with one that reflects what the share would have been with smoothed economic growth in order to approximate the impact of a recession on the health spending share. this exercise is a first approximation way to remove the influence of the gdp (denominator) from our analysis. a gap in the share of gdp accounted for by health then reflects a simulated or approximated impact of each recession. the results imply that for the 1980 - 1982 and 1990 - 1991 recessions, much of the spike in the marginal share was due to a contraction in gdp (figure 1). that is, without the cyclical nature of gdp, health 's contribution to gdp increases would not have spiked as severely, but instead would have continued to rise somewhat less slowly. the 2000 - 2001 recession was both milder and of shorter duration than the two earlier recessions. as our simulation illustrates, the most recent spike in the health share of gdp in 2000 - 2001 appears to have had little to do with the recession. instead, the primary cause was the faster annual growth in health expenditures, especially federal government spending. supplemental medicare funding through the balanced budget relief act and the benefits improvement and protection act converged for 2000 - 2001 as demands on medicaid also intensified, contributing to increased spending for these programs. since the expiration of this supplemental funding, however, the marginal share of gdp increases attributable to health has not fallen to levels comparable to those of other expansionary periods. this is the case, in part, because annual nhe growth has continued to increase at substantial rates after peaking at 9 percent in 2002 (centers for medicare & medicaid services, 2006). health spending continues to rise to new thresholds, even as payers search for new cost - containment tools. health expenditures accounted for a substantial 39 percent share of marginal nominal gdp growth in 2002, 27 percent in 2003, and 18 percent in 2004still higher than the historical average, and higher than similar periods of economic expansion. spending would have been even higher had some private employers not dropped coverage, reduced benefits, or increased cost sharing ; had supplemental funding provisions for medicare not expired ; and had states not aggressively pursued cost - containment strategies such as tightening eligibility requirements for medicaid. we can also use marginal analysis to monitor the impact of growing medicare spending on the federal budget over time. in the same way that the marginal share of the gdp devoted to health spikes when the economy contracts, medicare 's marginal share increases when federal outlays grow more slowly. the fiscal year (fy) 1987 peak can be explained by this phenomenon (figure 2). in 1987, annual medicare spending grew 7.0 percent and total federal outlay growth slowed significantly from 4.7 percent in fy 1986 to 1.3 percent in fy 1987, driven by pressure from the 1985 balanced budget and emergency deficit control act (gramm - rudman - hollings) (u.s. this act called for specific reductions in spending if the annual federal budget was not in balance, but was found unconstitutional in 1987. federal spending on health care, dominated by medicare, grew substantially faster than private - sector health spending between fys 1992 and 1997, in part because the private market more intensely embraced managed care and because long - term care was primarily left to the public sector. also, public programs by their very nature tend to respond slowly to cost pressures due to the legislative action process and the responsibility to provide benefits to a diverse mix of the population. in fact, the average share of the federal budget devoted to medicare increased more during this period than during any other over the past 25 years, from 8.6 percent in fy 1992 to 11.9 percent in fy 1997. medicare spending for home health and nursing home services grew quickly in this period due to increased pressure to provide home and community - based services for those with long - term care needs. by fy 1998, anticipation of the medicare cuts for home health and nursing homes imposed by the 1997 balanced budget act (bba) was already dampening overall medicare spending growth, while growth was further suppressed by fraud and abuse investigations (foster, 2000). following this period of significant expansion in medicare 's average share of federal outlays, interestingly enough, because of the bba, annual medicare spending growth was less than annual total federal outlay growth in fy 1998 for the only time in medicare 's 40-year history. in fact, from fys 1998 - 2000, incremental medicare spending growth was below its historical average share. this period was short lived as congress provided post - bba give backs to the health care industry and medicare spiked to a 27-percent share of the incremental growth in fy 2001. after a slight dip in marginal growth in fy 2002 due to an almost doubling of federal outlay annual growth, an increasing marginal share continued into fy 2005, as medicare grew to a 12-percent average share of the federal budget. using marginal analysis to better understand projections, a major impending financing challenge can be viewed in an alternative, less traditional way. figure 2 indirectly illustrates the increased strain that is created as medicare starts drawing down its trust fund assets. if there is no change in current law, omb states that the treasury will have to turn to the public capital markets to raise the funds to finance the benefits, just as if the trust funds had never existed. from the standpoint of overall government finances, the trust funds do not reduce the future burden of financing social security or medicare benefits.(u.s. similarly, the medicare trustees report goes on to discuss the financial squeeze that medicare would place on the budget : (t)he difference between hi [hospital insurance ] tax revenues and expenditures would be met for a number of years by interest earnings on trust fund assets and by redeeming those assets. both of these financial resources for the hi trust fund require cash transfers from the general fund of the treasury, thereby placing a further obligation on the budget(board of trustees, 2006). the increase in the federal budget, projected to be comprised of federal medicare and medicaid payments, is over 91 percent in fy 2007 and nearly 60 percent in fy 2008, respectively (figure 4). medicare is expected to account for nearly 80 percent of this increase in fy 2007 as the medicare prescription drug benefit becomes fully effective. according to omb projections this may be partly responsible for a reduction of other spending in the short term, including defense (minus 1.5 growth in fy 2007 and minus 6.3 percent growth in fy 2008), and education, training, employment, and social services (minus 20 percent growth in fy 2007). medicare 's share of the budget is expected to jump, from 12 percent in fy 2005 to 14 percent in fy 2008, a $ 106 billion increase. part of this increase can be attributed to a shift in spending from medicaid to medicare, as the medicare program picks up prescription drug spending for the dually eligible population. even before this benefit was added, promised medicare benefits were absorbing increasing marginal shares of federal outlays for fys 2004 and 2005. like federal medicare spending in fact, the federal medicaid share of total federal spending tripled from fys 1980 - 2005, from 2.4 to 7.4 percent (figure 3). during that time, federal medicaid spending grew an average of 10.8 percent annually, compared with the federal budget 's average annual growth of 5.9 percent (u.s. office of management and budget, 2006b). medicaid spending is affected by cyclical patterns of enrollment growth, changes in the interpretation of legislation, fiscal policy, and financial payment incentives. as was the case with medicare, the first marginal spike in fy 1987 was a result of slowed total federal outlays, while federal medicaid spending growth stayed relatively constant. during the period fys 1991 - 1993, increased state use of disproportionate share hospital (dsh) spending caused the federal medicaid marginal share to reach as high as 29 percent. dsh payments were used by states to shift a greater share of increasing costs of medicaid to the federal government. when combined with federal medicare spending, 70 percent of the increase in federal budget outlays in fy 1993 was attributable to these two programs (figure 4). in response to the accelerated growth of the early 1990s, medicaid reform (that is, managed care and statewide cost control) reduced medicaid 's marginal share of federal spending growth from fys 1993 - 1996. from the late 1990s through the recession in 2001, and even into 2002, states used upper payment limits (upl) to increase federal payment, causing a spike in the medicaid share of federal outlay growth. marginal growth then slowed through fy 2003 as the federal government began to tighten control of these revenue - enhancing efforts. the slightly increased marginal growth in fy 2004 is primarily a result of the temporary increase to the federal matching rate for state medicaid payments in fys 2003 and 2004, which raised the share of medicaid spending paid for by the federal government (national governors ' association and national association of states ' budget officers, 2004). fy 2005 marked slowing marginal growth resulted from improved economic conditions and lowered spending growth for prescription drugs. recent omb projections are that marginal federal contributions to medicaid program growth will continue below the average share in fy 2006 as the federal government allocates funding for the expected increased costs for the dually eligible under the new medicare prescription drug benefit. this occurs in part because the 2005 deficit reduction act is expected to produce reductions in medicaid outlays of $ 6.9 billion through fy 2010 (u.s. congressional budget office, 2006) as the aforementioned planned reductions in defense and education work to reduce total federal outlays. after this slowdown, the federal marginal medicaid share is projected to be higher than the average share, peaking in fy 2008. finally, medicaid is expected to return to an annual rate of growth that is more consistent with its historical trend after the medicare prescription drug, improvement, and modernization act of 2003 moves some federal medicaid expenditures to the medicare program in fys 2006 and 2007. states ' medicaid share of total state outlay growth does not spike during recessionary periods like we 've discussed for the overall economy and the federal medicare and medicaid share of total government outlays (figure 5). this observation at first seems counterintuitive, as eligibility for medicaid should rise during recessions. however, the requirement of most state and local governments to maintain balanced budgets in each fy may be the more important driver. during times of tightened budgets, states must scrutinize their expenses, and as a result, they occasionally turn to federally matched payment programs as a way to shift payment burdens to the federal government, in effect reducing the state and local share of outlays. for example, states used dsh funding to help with the financial pressures associated with the 1991 recession, enabling states to provide a level of services that otherwise would have been unaffordable (medicare payment advisory commission, 2001). eventually, as the federal government began to retract dsh funding, states were not willing or able to scale down benefits as rapidly, resulting in greater strain on their budgets as the postponed effects of the recession came to fruition. in doing so, states total outlay spending annual growth slowed from calendar years (cy) 19921995, but state medicaid expenditure annual growth remained above 10 percent. the 1992 - 1995 cy period of high growth sparked congressional momentum to control costs by converting medicaid into a block grant program. although this never happened, anticipation of the legislative change caused many states to run up costs in cy 1995, the base year for the block grant calculation, contributing to the substantial slowdown in marginal growth seen in cy 1996 (klemm, 2000). the cy 1998 marginal spike can be attributed to health spending increases in administrative costs, hospital services, and prescription drugs. from cys 19972000 states began relying on upper - payment - limit rules to secure a greater share of federal funding. in effect, states paid providers at enhanced rates, earned federal matching funds at these high rates, and then recouped a portion of the money. this temporarily brought more funding into states for both health and potentially non - health outlays, causing the state marginal share to be only slightly above that of the average share. a tightening of the rules for upl in cys 2002 and 2003 combined with further restrictions on dsh payments in cys 2001 - 2003 and the 2001 recession, led the marginal share to move upward as states shouldered a larger proportionate share of actual medicaid burden. in late cy 2003 and cy 2004, the temporary federal match rate increase included in the 2003 jobs and growth tax reconciliation act intended to relieve some of the financial pressures of health care obligations by states. the increased federal matching rates enticed states to increase health spending faster than all other spending in cy 2004, creating a marginal spike of roughly 13.7 percent, one of the highest levels in the past 24 years. the average health spending share of gdp is frequently cited as a measure of the ability and willingness of society to purchase health care. while the average share yields information about the magnitude of health spending in relationship to gdp, it does not indicate whether health spending increased its share of total spending relative to all other spending in a given year. one way to provide some insight into this question would be to compare, for each year, the incremental increase in health spending to that year 's additional resources available to pay for it. an increase in the incremental, or marginal, share of spending for health occurs when there is faster relative growth in health spending (the numerator) or slower relative growth in the resource constraint (the denominator) (kowalczyk, freeland, and levit, 1988). the analysis in this article is based on nominal values for health expenditures developed within the cms nhe accounting framework, nominal gdp, and nominal federal government outlays (bureau of economic analysis, 2006). additional elaboration and caveats regarding the estimates in this article are available on the internet at http://www.cms.hhs.gov/nationalhealthexpenddata/ or by request from the authors. as health spending grows faster than gdp in most years (table 1), health spending is higher at the margin than health spending as a share of gdp on average. this higher marginal relationship drives up the average share over time ; from 5.2 percent in 1960 to 16 percent in 2004. admittedly, if society were n't willing to change its preferences and health spending continued to grow significantly faster than gdp during expansionary periods, health expenditures could eventually consume almost all of the real marginal growth in a given year. to be sure, welfare can rise even if income less health care falls, because the benefits resulting from increased spending for health care can outweigh the losses in reduced consumption of other goods (johnson and penner, 2004). potentially, it may be sustainable to devote an increasing marginal share of gdp to health care as long as real spending on non - health services is preserved (chernew, hirth, and cutler, 2003). the marginal share during the 1970 - 1980 period (10.3 percent) foreshadowed an increase in the average health share of gdp, which surpassed the 10.3 percent threshold by 1983 (table 1). in the 1980 - 1990 period, the marginal share for health was 15.3 percent, a precursor of the average share reaching this level by 2002, despite policy changes that delayed this outcome. the most recent marginal share of 27 percent incurred in the 2000 - 2004 period indicates that health care may eventually reach a much higher average share of gdp. under cms current law projections, health care is expected to increase to 20 percent of gdp by 2015 (borger., 2006). we also find that a larger share of the increase in gdp is spent on health during recessionary periods (figure 1). to some extent, the countercyclical nature of health spending is beneficial in that it helps to cushion the impact of cyclical swings in gdp. for example, medicaid spending often increases during recessionary periods as the unemployment rate rises. a sharply rising marginal share often reflects the effect of a contraction in real gdp, and the effect becomes more significant as the average share of health to gdp increases. the relative severity of economic downturns has a significant impact on the magnitude of the spike in the marginal share. the recession of 1980 - 1982 was more severe than the 1990 - 1991 and 2000 - 2001 recessions. in 1982, health spending absorbed a much higher marginal share of gdp, at 29 percent, than had yet been experienced. as the pace of health spending in the 1980s grew rapidly and pressures to constrain growth were building, the economic contraction of 1990 - 1991 exacerbated the growing pressure from the health sector, with health spending absorbing 35 percent of nominal economic growth in 1991. employers responded to this situation by encouraging employees to enroll in managed care plans, whose enrollment captured 54 percent of all insured workers in 1993 and 86 percent of those workers by 1998 (levitt., 1999). enrollment in federal government - sponsored managed care plans also began to pick up in the 1990s. the most recent spike in the marginal share of gdp surpasses the levels shown for earlier periods. the marginal share reached 37 percent in the 2001 recession, which occurred simultaneously with the granting of supplemental funding to medicare providers and the reaching of the peak of the backlash against restrictive managed care arrangements. it is interesting to consider how much of the increase in the marginal share could be attributed to the period 's weakening economy, as opposed to the rising rate of health spending. that is, what would the health spending share of gdp growth have been if the economy, rather than contracting, had expanded at its average rate for the period ? what would the share have been during 2000 - 2001, when the recession was admittedly mild compared with the prior two recessions ? to simulate this, we redistributed the nominal economic growth that took place as the economy contracted then rebounded from each downturn. we then compared the data series that reflects the growth in marginal share during recessions with one that reflects what the share would have been with smoothed economic growth in order to approximate the impact of a recession on the health spending share. this exercise is a first approximation way to remove the influence of the gdp (denominator) from our analysis. a gap in the share of gdp accounted for by health then reflects a simulated or approximated impact of each recession. the results imply that for the 1980 - 1982 and 1990 - 1991 recessions, much of the spike in the marginal share was due to a contraction in gdp (figure 1). that is, without the cyclical nature of gdp, health 's contribution to gdp increases would not have spiked as severely, but instead would have continued to rise somewhat less slowly. the 2000 - 2001 recession was both milder and of shorter duration than the two earlier recessions. as our simulation illustrates, the most recent spike in the health share of gdp in 2000 - 2001 appears to have had little to do with the recession. instead, the primary cause was the faster annual growth in health expenditures, especially federal government spending. supplemental medicare funding through the balanced budget relief act and the benefits improvement and protection act converged for 2000 - 2001 as demands on medicaid also intensified, contributing to increased spending for these programs. since the expiration of this supplemental funding, however, the marginal share of gdp increases attributable to health has not fallen to levels comparable to those of other expansionary periods. this is the case, in part, because annual nhe growth has continued to increase at substantial rates after peaking at 9 percent in 2002 (centers for medicare & medicaid services, 2006). health spending continues to rise to new thresholds, even as payers search for new cost - containment tools. health expenditures accounted for a substantial 39 percent share of marginal nominal gdp growth in 2002, 27 percent in 2003, and 18 percent in 2004still higher than the historical average, and higher than similar periods of economic expansion. spending would have been even higher had some private employers not dropped coverage, reduced benefits, or increased cost sharing ; had supplemental funding provisions for medicare not expired ; and had states not aggressively pursued cost - containment strategies such as tightening eligibility requirements for medicaid. we can also use marginal analysis to monitor the impact of growing medicare spending on the federal budget over time. in the same way that the marginal share of the gdp devoted to health spikes when the economy contracts, medicare 's marginal share increases when federal outlays grow more slowly. the fiscal year (fy) 1987 peak can be explained by this phenomenon (figure 2). in 1987, annual medicare spending grew 7.0 percent and total federal outlay growth slowed significantly from 4.7 percent in fy 1986 to 1.3 percent in fy 1987, driven by pressure from the 1985 balanced budget and emergency deficit control act (gramm - rudman - hollings) (u.s. this act called for specific reductions in spending if the annual federal budget was not in balance, but was found unconstitutional in 1987. federal spending on health care, dominated by medicare, grew substantially faster than private - sector health spending between fys 1992 and 1997, in part because the private market more intensely embraced managed care and because long - term care was primarily left to the public sector. also, public programs by their very nature tend to respond slowly to cost pressures due to the legislative action process and the responsibility to provide benefits to a diverse mix of the population. in fact, the average share of the federal budget devoted to medicare increased more during this period than during any other over the past 25 years, from 8.6 percent in fy 1992 to 11.9 percent in fy 1997. medicare spending for home health and nursing home services grew quickly in this period due to increased pressure to provide home and community - based services for those with long - term care needs. by fy 1998, anticipation of the medicare cuts for home health and nursing homes imposed by the 1997 balanced budget act (bba) was already dampening overall medicare spending growth, while growth was further suppressed by fraud and abuse investigations (foster, 2000). following this period of significant expansion in medicare 's average share of federal outlays, congress took action to restrain medicare spending by passing the bba. interestingly enough, because of the bba, annual medicare spending growth was less than annual total federal outlay growth in fy 1998 for the only time in medicare 's 40-year history. in fact, from fys 1998 - 2000, incremental medicare spending growth was below its historical average share. this period was short lived as congress provided post - bba give backs to the health care industry and medicare spiked to a 27-percent share of the incremental growth in fy 2001. after a slight dip in marginal growth in fy 2002 due to an almost doubling of federal outlay annual growth, an increasing marginal share continued into fy 2005, as medicare grew to a 12-percent average share of the federal budget. using marginal analysis to better understand projections, a major impending financing challenge can be viewed in an alternative, less traditional way. figure 2 indirectly illustrates the increased strain that is created as medicare starts drawing down its trust fund assets. if there is no change in current law, omb states that the treasury will have to turn to the public capital markets to raise the funds to finance the benefits, just as if the trust funds had never existed. from the standpoint of overall government finances, the trust funds do not reduce the future burden of financing social security or medicare benefits.(u.s. similarly, the medicare trustees report goes on to discuss the financial squeeze that medicare would place on the budget : (t)he difference between hi [hospital insurance ] tax revenues and expenditures would be met for a number of years by interest earnings on trust fund assets and by redeeming those assets. both of these financial resources for the hi trust fund require cash transfers from the general fund of the treasury, thereby placing a further obligation on the budget(board of trustees, 2006). the increase in the federal budget, projected to be comprised of federal medicare and medicaid payments, is over 91 percent in fy 2007 and nearly 60 percent in fy 2008, respectively (figure 4). medicare is expected to account for nearly 80 percent of this increase in fy 2007 as the medicare prescription drug benefit becomes fully effective. according to omb projections this may be partly responsible for a reduction of other spending in the short term, including defense (minus 1.5 growth in fy 2007 and minus 6.3 percent growth in fy 2008), and education, training, employment, and social services (minus 20 percent growth in fy 2007). medicare 's share of the budget is expected to jump, from 12 percent in fy 2005 to 14 percent in fy 2008, a $ 106 billion increase. part of this increase can be attributed to a shift in spending from medicaid to medicare, as the medicare program picks up prescription drug spending for the dually eligible population. even before this benefit was added, promised medicare benefits were absorbing increasing marginal shares of federal outlays for fys 2004 and 2005. like federal medicare spending, federal medicaid expenditures have consumed an increasing share of the federal budget. in fact, the federal medicaid share of total federal spending tripled from fys 1980 - 2005, from 2.4 to 7.4 percent (figure 3). during that time, federal medicaid spending grew an average of 10.8 percent annually, compared with the federal budget 's average annual growth of 5.9 percent (u.s. office of management and budget, 2006b). medicaid spending is affected by cyclical patterns of enrollment growth, changes in the interpretation of legislation, fiscal policy, and financial payment incentives. as was the case with medicare, the first marginal spike in fy 1987 was a result of slowed total federal outlays, while federal medicaid spending growth stayed relatively constant. during the period fys 1991 - 1993, increased state use of disproportionate share hospital (dsh) spending caused the federal medicaid marginal share to reach as high as 29 percent. dsh payments were used by states to shift a greater share of increasing costs of medicaid to the federal government. when combined with federal medicare spending, 70 percent of the increase in federal budget outlays in fy 1993 was attributable to these two programs (figure 4). in response to the accelerated growth of the early 1990s, medicaid reform (that is, managed care and statewide cost control) reduced medicaid 's marginal share of federal spending growth from fys 1993 - 1996. from the late 1990s through the recession in 2001, and even into 2002, states used upper payment limits (upl) to increase federal payment, causing a spike in the medicaid share of federal outlay growth. marginal growth then slowed through fy 2003 as the federal government began to tighten control of these revenue - enhancing efforts. the slightly increased marginal growth in fy 2004 is primarily a result of the temporary increase to the federal matching rate for state medicaid payments in fys 2003 and 2004, which raised the share of medicaid spending paid for by the federal government (national governors ' association and national association of states ' budget officers, 2004). fy 2005 marked slowing marginal growth resulted from improved economic conditions and lowered spending growth for prescription drugs. recent omb projections are that marginal federal contributions to medicaid program growth will continue below the average share in fy 2006 as the federal government allocates funding for the expected increased costs for the dually eligible under the new medicare prescription drug benefit. this occurs in part because the 2005 deficit reduction act is expected to produce reductions in medicaid outlays of $ 6.9 billion through fy 2010 (u.s. congressional budget office, 2006) as the aforementioned planned reductions in defense and education work to reduce total federal outlays. after this slowdown, the federal marginal medicaid share is projected to be higher than the average share, peaking in fy 2008. finally, medicaid is expected to return to an annual rate of growth that is more consistent with its historical trend after the medicare prescription drug, improvement, and modernization act of 2003 moves some federal medicaid expenditures to the medicare program in fys 2006 and 2007. states ' medicaid share of total state outlay growth does not spike during recessionary periods like we 've discussed for the overall economy and the federal medicare and medicaid share of total government outlays (figure 5). this observation at first seems counterintuitive, as eligibility for medicaid should rise during recessions. however, the requirement of most state and local governments to maintain balanced budgets in each fy may be the more important driver. during times of tightened budgets, states must scrutinize their expenses, and as a result, they occasionally turn to federally matched payment programs as a way to shift payment burdens to the federal government, in effect reducing the state and local share of outlays. for example, states used dsh funding to help with the financial pressures associated with the 1991 recession, enabling states to provide a level of services that otherwise would have been unaffordable (medicare payment advisory commission, 2001). eventually, as the federal government began to retract dsh funding, states were not willing or able to scale down benefits as rapidly, resulting in greater strain on their budgets as the postponed effects of the recession came to fruition. in doing so, states total outlay spending annual growth slowed from calendar years (cy) 19921995, but state medicaid expenditure annual growth remained above 10 percent. the 1992 - 1995 cy period of high growth sparked congressional momentum to control costs by converting medicaid into a block grant program. although this never happened, anticipation of the legislative change caused many states to run up costs in cy 1995, the base year for the block grant calculation, contributing to the substantial slowdown in marginal growth seen in cy 1996 (klemm, 2000). the cy 1998 marginal spike can be attributed to health spending increases in administrative costs, hospital services, and prescription drugs. from cys 19972000 states began relying on upper - payment - limit rules to secure a greater share of federal funding. in effect, states paid providers at enhanced rates, earned federal matching funds at these high rates, and then recouped a portion of the money. this temporarily brought more funding into states for both health and potentially non - health outlays, causing the state marginal share to be only slightly above that of the average share. a tightening of the rules for upl in cys 2002 and 2003 combined with further restrictions on dsh payments in cys 2001 - 2003 and the 2001 recession, led the marginal share to move upward as states shouldered a larger proportionate share of actual medicaid burden. in late cy 2003 and cy 2004, the temporary federal match rate increase included in the 2003 jobs and growth tax reconciliation act intended to relieve some of the financial pressures of health care obligations by states. the increased federal matching rates enticed states to increase health spending faster than all other spending in cy 2004, creating a marginal spike of roughly 13.7 percent, one of the highest levels in the past 24 years. the united states faces increasingly challenging tradeoffs as health spending continues to outpace growth in the economy and in governments ' budgets. using marginal analysis, we have illustrated the impact of purchasers ' incremental decisions at the aggregate economy, federal, and state and local levels. to reach projected health spending consumption of 20 percent of gdp by 2015, society must be willing to spend between 20 and 40 percent of incremental nominal gdp growth on health each year over the next 10 years (near its all - time highs reached between 2000 and 2004) (borger., 2006). it seems clear that all else being equal, society will continue to demand increasing amounts of health care. however, as the share of resources devoted to health care increases, so does the opportunity and marginal costs of forgoing other goods and services. these increasingly sensitive choices may compel society to reduce the rate of the increase of health care consumption or alter the distribution of the burden to be paid. to be sure, the future will lead to even higher scrutiny of health care spending dollars, which may lead to innovative cost - reducing technologies and payment systems that slow the growth of health care spending in the future and increase its value to all. | with each passing decade, health care has consumed a larger share of gross domestic product (gdp) and federal budgets. by the 2000 - 2004 period, society was willing to devote over 20 percent of the cumulative increase in gdp and the cumulative increase in federal outlays towards health care. the financing challenges are expected to become more acute for private payers as well as federal, state, and local budgets. with the implementation of part d in 2006, the u.s. office of management and budget projects that federal budget pressures will heighten, bringing increased attention to medicare 's long - term fiscal outlook. |
alex krill and co - authors in 1969, were the first to use multifocal choroiditis (mfc) to describe a non - infectious, idiopathic ocular disorder resembling the presumed ocular histoplasmosis syndrome nozik and dorsch in 1973 described a similar chorioretinopathy associated with anterior uveitis in two patients with fundus lesions similar to pohs, but with the presence of vitreous and anterior chamber inflammation, but no evidence of infectious disease. dreyer and gass in 1984 were the first to report mfcpu in a larger series of 28 cases confirming it as a distinct clinical entity from pohs. in the same year, watzke described ten myopic women with mfc but with smaller chorioretinal lesions and called these cases punctate inner choroidopathy these authors believed that pic is a distinctive entity in which small yellow - gray dots in the posterior pole with no signs of ocular inflammation develop into atrophic chorioretinal scars and become progressively more pigmented with time. joondeph and tessler in 1990 were the first to use the terms mfc and pic as inflammatory disorders distinct from pohs, which predominantly affect young myopic females. they described mfc as a chronic bilateral disease that was variably associated with vitritis, and often with anterior chamber inflammation which may also show progressive subretinal fibrosis and macular choroidal neovascularization. since then, there has been no evidence to support mfc and pic as separate entities : their clinical course and treatments are similar, and both conditions are idiopathic. causes of mfc lesions can be classified into infectious (pohs, tuberculosis, brucellosis, coccidiomycosis, candidiasis and other fungal septicemias, syphilis, west nile virus, etc.), noninfectious [sarcoidosis and other granulomatous diseases (e.g., blau syndrome) ], and idiopathic [without uveitis, or with uveitis (mfcpu) ]. idiopathic mfc generally describes a relatively uncommon, chronic, inflammatory chorioretinopathy that predominantly affects young (median age of 30 years) healthy myopic white women with no known associated systemic disease or other recognized ocular syndromes, and a high risk of secondary cnv, circumscribed areas of chorioretinal atrophy and subretinal pigmented fibrotic scars. although idiopathic mfc may represent an ocular manifestation of an autoimmune disease in genetically susceptible patients, the precise etiopathogenesis still remains unclear. clinically, patients may complain of a temporal scotoma, metamorphopsia, floaters, photopsias, photophobia, and decreased vision. affected eyes typically show multiple punched - out chorioretinal lesions ranging from 50 to 350 m in size, both the posterior pole and periphery, often with clustering of lesions nasal to the disc, with minimal or no anterior uveitis or vitritis and no signs of progressive or diffuse subretinal fibrosis. other findings include peripapillary atrophy, scarring, and curvilinear chorioretinal streaks (schlaegel lines) in the far periphery [figure 1 ]. patients have negative or nonreactive results on relevant diagnostic modalities ; such as histoplasmin skin reaction, syphilis (non - treponemal and treponemal) serology, tests for tuberculosis (tuberculin skin test or interferon- release assays and chest radiographs), tests for sarcoidosis (serum angiotensin - converting enzyme and chest radiograph or computed tomography scan) and neoplastic / non - neoplastic anti - retinal antibodies. color fundus photograph of a 21-year - old man, presenting with blurred vision and floaters in both eyes over several months. note multiple, diffuse and discrete nummular outer retinal / choroidal white spots and equatorial linear / curvilinear streak lesions (schlaegel lines) in the left eye. primary vitreoretinal lymphoma (also known as primary central nervous system lymphoma with ocular involvement), causes subretinal pigment epithelium (sub - rpe) nodular elevations about 100 m in diameter which demostrate autofluorescence and fluorescein angiographic findings similar to those seen in mfc. usually idiopathic mfc can be distinguished from masqueraders based on clinical manifestations, fundus imaging, and clinical course. peripheral mfc is a non - infectious type of the disease and strongly associated with sarcoidosis, characterized by a rather poor visual outcome, macular edema and relatively high prevalence of complications. mfcpu is a variant of idiopathic mfc that has been described in association with anterior uveitis and/or vitritis, multiple punched - out atrophic chorioretinal lesions of variable size (typically 5001000 m in size) in the posterior pole and midperiphery of the retina, older age and more visual impairment at presentation. this type of the disease is more frequently associated with a non - remitting clinical course and higher frequency of structural complications such as cataract, cystoid macular edema (cme), and epiretinal membrane (erm) related to intraocular inflammation. mfcpu has a poor visual prognosis for both eyes, and normally requires higher levels of maintenance immunosuppression. haplotyping of elderly patients with mfcpu has shown significantly reduced frequency of hla b-7, hla- dr1, and hla- dr15. some authors have used the term pic to designate the non - inflammatory aspect of the disease, but, most authors believe that idiopathic mfc and pic represent the same underlying disease entity and both are associated with identical interleukin-10 and tumor necrosis factor (tnf) haplotypes. idiopathic mfc generally describes a relatively uncommon, chronic, inflammatory chorioretinopathy that predominantly affects young (median age of 30 years) healthy myopic white women with no known associated systemic disease or other recognized ocular syndromes, and a high risk of secondary cnv, circumscribed areas of chorioretinal atrophy and subretinal pigmented fibrotic scars. although idiopathic mfc may represent an ocular manifestation of an autoimmune disease in genetically susceptible patients, the precise etiopathogenesis still remains unclear. clinically, patients may complain of a temporal scotoma, metamorphopsia, floaters, photopsias, photophobia, and decreased vision. affected eyes typically show multiple punched - out chorioretinal lesions ranging from 50 to 350 m in size, both the posterior pole and periphery, often with clustering of lesions nasal to the disc, with minimal or no anterior uveitis or vitritis and no signs of progressive or diffuse subretinal fibrosis. other findings include peripapillary atrophy, scarring, and curvilinear chorioretinal streaks (schlaegel lines) in the far periphery [figure 1 ]. patients have negative or nonreactive results on relevant diagnostic modalities ; such as histoplasmin skin reaction, syphilis (non - treponemal and treponemal) serology, tests for tuberculosis (tuberculin skin test or interferon- release assays and chest radiographs), tests for sarcoidosis (serum angiotensin - converting enzyme and chest radiograph or computed tomography scan) and neoplastic / non - neoplastic anti - retinal antibodies. color fundus photograph of a 21-year - old man, presenting with blurred vision and floaters in both eyes over several months. note multiple, diffuse and discrete nummular outer retinal / choroidal white spots and equatorial linear / curvilinear streak lesions (schlaegel lines) in the left eye. primary vitreoretinal lymphoma (also known as primary central nervous system lymphoma with ocular involvement), causes subretinal pigment epithelium (sub - rpe) nodular elevations about 100 m in diameter which demostrate autofluorescence and fluorescein angiographic findings similar to those seen in mfc. usually idiopathic mfc can be distinguished from masqueraders based on clinical manifestations, fundus imaging, and clinical course. peripheral mfc is a non - infectious type of the disease and strongly associated with sarcoidosis, characterized by a rather poor visual outcome, macular edema and relatively high prevalence of complications. mfcpu is a variant of idiopathic mfc that has been described in association with anterior uveitis and/or vitritis, multiple punched - out atrophic chorioretinal lesions of variable size (typically 5001000 m in size) in the posterior pole and midperiphery of the retina, older age and more visual impairment at presentation. this type of the disease is more frequently associated with a non - remitting clinical course and higher frequency of structural complications such as cataract, cystoid macular edema (cme), and epiretinal membrane (erm) related to intraocular inflammation. mfcpu has a poor visual prognosis for both eyes, and normally requires higher levels of maintenance immunosuppression. haplotyping of elderly patients with mfcpu has shown significantly reduced frequency of hla b-7, hla- dr1, and hla- dr15. some authors have used the term pic to designate the non - inflammatory aspect of the disease, but, most authors believe that idiopathic mfc and pic represent the same underlying disease entity and both are associated with identical interleukin-10 and tumor necrosis factor (tnf) haplotypes. idiopathic mfc is a chronic progressive bilateral disease and one of the most common causes of visual loss in this entity is related to development of cnv. the rate of increase in the size and number of lesions and development of new or recurrent cme and/or cnv is also high despite the relative absence of anterior uveitis or vitritis. this observation reflects the need for long term follow - up and lends further support to the proposition that inflammation in idiopathic mfc can be confined to the outer retina / rpe. despite these and other complications, visual acuity can be maintained over many years and the visual prognosis is good in most cases. according to spaide the principal sites involved appear to be the sub - rpe and outer retinal spaces. acute lesions are often associated with more widespread involvement of the ellipsoid zone (ez) extending beyond the zones of rpe involvement, as discontinuity or elevation due to deposition of material, which may be homogenous or heterogenous. active lesions show a consistent appearance of rpe elevation due to deposition of homogenous material of medium reflectivity on sd - oct examination. the rpe elevations are usually conical although larger ones are broader in the lateral dimension but similar in height. some of the solid rpe detachments appear to rupture through the rpe resulting in an outpouring of infiltrates into the outer retina. with separation or attenuation of the rpe line, there is increased light penetration into the choroid and deeper structures. edi - oct imaging of the choroid beneath the active lesions show a small increase in choroidal thickness as compared with the surrounding choroid in some eyes. other than these rather subtle findings, there do not appear to be any other choroidal perturbations. by autofluorescent however, if there is dehiscence of the rpe, a corresponding spot of absent autofluorescence is observed. the infiltrative changes in the outer retina extend both above and laterally from the apex of the ruptured rpe elevation. in some patients as the inflammatory episodes continue to recur, additional heterogeneous zonal, multizonal or diffuse outer retinal atrophy may appear similar to the development of chorioretinal scars, and some may even progress to end - stage patterns of chorioretinal atrophy (a new variant). this variant of idiopathic mfc with atrophy, involving the posterior pole and peripheral fundus, may demonstrate chorioretinal lesions and a spectrum of zonal, multizonal or diffuse outer retinal, rpe, and/or chorioretinal atrophy. there may be foveal sparing until late into the disease course in the involved eyes. this phenomenon is distinct from focal lesions seen in eyes with typical mfc. within the chorioretinal atrophic zones, spectral domain optical coherence tomography (sd - oct) and fundus autofluorescence (faf) inflammation may initially affect only the outer parts of photoreceptors and cause an associated visual field scotoma. as bouts of inflammation recur, continued progression to multizonal or diffuse disease may occur. eventually, involvement of the rpe and choroid leads to end - stage disease, which causes severe chorioretinal atrophy. foveal sparing is common until late in the disease course in these patients, and the majority of patients maintain good visual acuity. munk, however, reported eight patients with idiopathic mfc with atrophy associated with adjacent photoreceptor attenuation, an acute / subacute onset of decreased visual acuity and scotomata with vision loss as severe as counting fingers / hand motion. visual acuity fully recovered in only three of the eight cases after treatment with corticosteroids and/or systemic mycophenolate mofetil (mmf) but no other agents such as cyclosporine, methotrexate, azathioprine, infliximab, or tacrolimus were used. this variant of idiopathic mfc with atrophy, unlike classic acute zonal occult outer retinopathy, does not demonstrate the pathognomonic orange to - gray demarcating line on ophthalmoscopic examination and the typical trizonal degeneration, visualized on faf, indocyanine green angiography (icg), and oct images. interestingly, genetic factors including inflammatory complement factor h have a strong association with mfc and age - related macular degeneration. having an underlying genetic susceptibility may predispose a single patient to more than one inflammatory disease. the occurrence of mfc in siblings also raises the possibility of a familial association in the pathogenesis of the disease. currently, when there is no evidence of cnv, there is no universally accepted standard treatment for the majority of patients with idiopathic mfc as the visual prognosis is excellent. the only exception to this would be those patients with inflammatory lesions very close to fovea in whom medical treatment should be considered. systemic corticosteroid therapy is typically the first - line treatment, and in conjunction with immunomodulatory therapy, has shown to reduce the amount of inflammatory infiltration of the subretinal space and outer retina, and reduce damage seen on multimodal imaging. some authors believe that single - agent immunosuppression is able to achieve treatment success in the majority of patients, but dose escalation of mycophenolate mofetil (mmf) is typical, and a second immunosuppressive agent is needed in about one - fifth of the patients. from the authors point of view, both anti - inflammatory and anti - vegf therapy (in the presence of cnv) are necessary in the acute stage to control the inflammation and cnv. however, when neovascularization has subsided there is no standard method of management based on clinical trials for long - term immunosuppression therapy of the quiescent stage in young female patients of child - bearing age. | idiopathic multifocal choroiditis (mfc) and/or punctate inner choroidopathy (pic) describe a chronic progressive bilateral inflammatory chorioretinopathy that predominantly affect healthy myopic white women with no known associated systemic or ocular diseases. the principal sites of involvement are the retinal pigment epithelium (rpe) and outer retinal spaces ; the choroid is not affected during the active phase of the disease. idiopathic mfc with atrophy is a recently described variant. although there is no generally accepted standard treatment, anti - inflammatory and anti - vegf (vascular endothelial growth factor) agents are necessary in the acute stage to control the inflammation and choroidal neovascularization (cnv). |
traumatic brain injuries (tbi) is steadily increasing and is a major cause of mortality and morbidity, particularly in the young population, leading to the loss of life and productivity in the developing countries.[14 ] providing critical care to these patients with tbi is a challenge even in well - advanced centers in major cities of india.[48 ] in the present study, we describe our experience of critical care unit (ccu) resource utilization in the management of tbi from a rural setup. the present study was a retrospective review performed at acharya binova bhave rural hospital (avbrh), sawangi (meghe). avbrh is a 900 bedded teaching hospital cum tertiary referral center situated in rural area of central india. all consecutive patients who were admitted in the ccu for the management of traumatic brain injury were included in the study. the case records of the patients were reviewed retrospectively, and data were collected on age, gender, severity of head injury, associated injuries, total ccu stay, total hospital stay, and outcome. the biochemical investigations were performed only where and when necessary. based on the neurologic status and status of the associated injuries, patients were managed conservatively and all the patients were managed as per the standard protocol and maximally aggressive therapy aimed at diminishing intracranial pressure and elevating cerebral perfusion pressure was pursued in every case. indications for surgery were operable lesions on ct scan. based on glasgow coma scale (gcs), the severity of head injury was defined as mild (gcs : 1315), moderate (gcs : 912), and severe (gcs : 38). all the patients with a gcs score of 8 or less, respiratory distress, or shock were intubated, ventilated, and sedated as necessary. tracheostomy was performed where there was poor neurological status, prolonged intubation, ventilation, and facial injuries. all patients were provided with supportive care and received regular physiotherapy for their physical disability and respiratory problems. all statistical analyses were carried out using spss software version 11.0 (spss inc., chicago il). logistic regression analysis was used to identify risk factors associated with ccu mortality at various day and times of admission. all statistical analyses were carried out using spss software version 11.0 (spss inc., chicago il). logistic regression analysis was used to identify risk factors associated with ccu mortality at various day and times of admission. during the study period, a total 381 patients were admitted to the intensive care unit for the management of head injury. there were total 303 males and 78 females [figure 1 ]. the majority of the patients were in their 3, 4, and 5 decade [figure 2 ]. the mean age of the subjects was 37.7816.99 years and median age was 36 years. the total duration (days) of hospital stay was 8.966.16 days and median of 8 days, ccu stay was 3.776.34 days with median of 2 days [table 1 ]. it was evident that majority of the death in severe gcs was in less than 24 h, that is, 44 (100%), whereas those subjects who were in ccu for 27 days among them 14 (21.21%) died, whereas only 4 (11.43%) died in ccu who stayed for 814 days, out of the 62 deaths, which occurred among the severe gcs. no deaths occurred in ccu subjects who stayed for more than 15 days [table 3 ]. the deaths which occurred in moderate gcs were within 24 h among 11 (5.50%) subjects of the 200 subjects. no deaths occurred in mild gcs subjects. a total 73 (19.16%) deaths occurred in 381 admitted subjects in ccu. the risk of death among both the sexes is not significantly different, that is, or, 1.032 (95% ci, 0.3513.03), so also the risk of death among the different age groups is also not significant having or, 0.978 (95% ci, 0.9541.00). while, the gcs (mild, moderate, and severe) and ccu stay parameters were having significant difference with risk of death having or, 3.22 (95% ci, 2.494.16) and or, 2.50 (95% ci, 1.93.2) [table 4 ]. demographic profile of study population pattern of injuries in patients admitted to ccu clinical traumatic brain injury (n=381) duration of stay in icu, severity of head injury and outcome multiple logistic regression of outcome with sex, age, and duration of stay as in any other injuries, the majority of victims of traumatic brain injury patients are male and in younger age groups ; and is explained by the fact that during this age, people, especially males are more mobile, go out for work and take risks, while elderly people, females, and children usually stay at home. initial gcs and severity of brain injury was used to match tbi patients and lower initial gcs can be due to greater severity of brain injury and also possible because of decreased brain perfusion (perhaps reflecting inadequate resuscitation). it has been concluded that the gcs score may be used to stratify and predict mortality risk in intensive care patients, but it may lack sensitivity. resource limitation in developing countries restricts the routine use of aggressive pre- and inhospital management strategies, such as intracranial pressure monitoring for patients with head injury, and many strategies have been developed to overcome these limitations and also to improve outcome in resource constrained environment. despite the limitations of our trauma care system and resource limitations, mortality among traumatic brain injury patients can be reduced if every caregiver, from the site of injury to the ccu, maintains hemodynamic stability (diastolic blood pressure > 70 mmhg and systolic bp > 90 mmhg) at all times. as in the present study, prolonged ccu lengths of stay can have increased survival rates, acceptable mortality rates, and quality of life despite significant costs.[1416 ] one of the limitations of this present study is that we do not know about patients who were injured and did not reach hospital and those with nonfatal severe injuries in the city received hospital care. apparently it seems possible to use existing health care structures in rural areas to improve trauma care and it becomes particularly relevant in poor resource, developing countries, where health care facilities and access to specialized care units are still far below the acceptable standard, there is a need to compare with the reference group to further support the evidence. although the present article may not change the way critical care is provided, we believe that it will give clinicians and their associates a fair idea of what to expect (and possibly to prepare families / survivors for) regarding the prognosis and path of critical care in the time to come, particularly in rural areas where the resources are limited. | introduction : traumatic brain injuries (tbi) are steadily increasing and are a major cause of mortality and morbidity, particularly in the young population, leading to the loss of life and productivity in the developing countries. providing critical care to these patients with tbi is a challenge even in well - advanced centers in major cities of india. in the present study, we describe our experience of resource utilization in the management of tbi in a critical care unit (ccu) from a rural setup.materials and methods : all consecutive patients who were admitted from january 2007 to december 2009 in the ccu for the management of traumatic brain injury were included in the study. the case records of the patients were reviewed retrospectively, and data were collected on age, gender, severity of head injury, associated injuries, total ccu stay, total hospital stay, and outcome.results:the total duration (days) of hospital stay was 8.966.16 days and a median of 8 days, and ccu stay was 3.776.34 days with a median of 2 days. no deaths occurred with mild head injury. a total of 73 (19.16%) deaths occurred in 381 admitted subjects in ccu. the risk of death among both the sexes is not significantly different, that is, odds ratio (or) 1.032 [95% confidence interval (ci) 0.3513.03 ], so also the risk of death among the different age groups is also not significant having or, 0.978 (95% ci, 0.9541.00). the severity of head injury (mild, moderate, and severe) and ccu stay parameters had significant difference with risk of death [or, 3.22 (95% ci, 2.494.16) and or, 2.50 (95% ci, 1.93.2)].conclusions : apparently it seems possible to use the existing health care structures in rural areas to improve trauma care. it becomes particularly relevant in poor resource, developing countries, where health care facilities and access to specialized care units are still far below the acceptable standard, there is a need to compare with the reference group to further support the evidence. |
bacterial strains - table shows the epidemiological and microbiological features of the partially studied c. striatum strains used in this investigation (baio. 2013). c. striatum identification was established by 16s rrna and rpob gene sequencing. c. striatum pulsotypes i and ii exhibited mdr profiles showing susceptibility only to vancomycin, linezolid and tetracycline, while c. striatum pulsotypes iii and iv showed susceptibility to most of the 21 antimicrobial agents tested and resistance only to fosfomycin and ticarcillin / clavulanate. the c. diphtheriae cat5003748 strain was used as a positive control in all experiments (gomes. tableorigin and pulsed - field gel electrophoresis (pfge)-types of partially studied corynebacterium striatum strains isolated from patients during a nosocomial outbreak in the metropolitan area, rio de janeiro, brazil used in this studystrains / yeargender/ agehospital wardsisolation siteoutcomeantimicrobial susceptibility patternspfge- types1987 br - rj/09f/50nursery 18baldeathmdri2369 br - rj/09m / nigeneral icutacuremdrii1961 br - rj/09f/37infectious diseasesurinenimdsiii1954 br - rj/09m / nithoracic msusurgical woundnimdsivbal : bronchoalveolar lavage ; f : female ; icu : intensive care unit ; m : male ; mdr : multiresistance (3 types of antimicrobial agents) ; mds : multidrug susceptible ; msu : medical surgical unit ; ni : not informed ; ta : tracheal aspirate ; bal : bronchoalveolar lavage ; f : female ; icu : intensive care unit ; m : male ; mdr : multiresistance (3 types of antimicrobial agents) ; mds : multidrug susceptible ; msu : medical surgical unit ; ni : not informed ; ta : tracheal aspirate ; biofilm formation on hydrophilic surfaces of glass tubes - microorganisms were inoculated in glass tubes (13 x 100 mm) containing 4 ml of trypticase soy broth (tsb) and incubated at 37c for 24 h without shaking. the tubes were gently shaken and supernatants with nonadherent bacterial cells were discarded. tsb (4 ml) was then added and the tubes were reincubated at 37c for 24 h. this procedure was repeated twice. glass - adherent bacteria created a confluent coat of cells on the sides of the tube. quantitative analysis of viable sessile cells was based on previously described methods (mattos - guaraldi & formiga 1991, dooley. 1996). quantitative and semiquantitative analyses of biofilm formation on catheter - polyurethane 16-gauge percutaneous nephrostomy catheters (intracath ; deseret pharmaceutical co, usa) were used for an evaluation of bacterial adherence and biofilm formation on catheter surfaces. sterile 4-cm segments of polyurethane catheters were immersed in tsb containing 10 colony - forming unit (cfu) ml and incubated at 37c for 24 h (gomes. 1996) and a semiquantitative roll - plate technique (maki. 1977) were performed using columbia agar medium supplemented with 5% sheep blood at 37c for 24 h. scanning electron microscopy (sem) - sections of glass coverslips and polyurethane catheters were fixed in 2.5% glutaraldehyde, post - fixed in 1% osmium tetroxide and dehydrated in a graded series of ethanol. subsequently, catheter segments were subjected to critical point drying with carbon dioxide, covered with a 10 nm layer of gold palladium and examined with a jeol jsm 5310 scanning electron microscope. sterile unused polyurethane catheters were also processed by sem directly upon removal from commercial packaging (gomes. biofilm formation on hydrophobic polystyrene surfaces - biofilm formation on negatively charged polystyrene surfaces was determined quantitatively in 96-well flat - bottomed microtitre plates according to previously described methods (stepanovic. aliquots of 200 l of bacterial suspensions [0.2 optical density (od) at =570 nm ] were added to the microplate wells. after incubation at 37c for 24 h, the contents of each well were aspirated and washed three times with 200 l phosphate - buffered saline (0.01 m, ph 7.2). the remaining attached bacteria were fixed with 200 l of 99% methanol and stained with 2% crystal violet. the bound dye was then solubilised with 160 l of 33% glacial acetic acid and the od of the solution was measured at = 570 nm using an enzyme immunosorbent assay reader (biorad, model 550). the cut - off od (odc) was defined as the mean od of the negative control. all strains were classified into the following categories based on the ods of the bacterial films : nonadherent (0 : od odc) or weakly (+ : odc 15 cfu) and by quantitative catheter culture assays (> 1.5 x 10cfu) showed that viable c. striatum cells were extensively adherent to and multiplied on the polyurethane catheter surface (fig., the representative side figure illustrates bacterial growth on an agar plate after catheter colonisation, as assessed by the roll - plate technique. although all strains were able to adhere to the catheter surface, the c. striatum 1987/i - mdr strain again exhibited significantly greater adherence (p 0.05. several microorganisms use extracellular matrix proteins, such as fbg, to increase their ability to interact with different cells and also with abiotic surfaces. to investigate the influence of fbg on the ability of c. striatum to adhere to plastic microtitre plates, plates were pre - treated with human plasmatic fbg prior to bacterial colonisation. as shown in fig. 4, human fbg enhanced biofilm formation on the polystyrene surfaces by the c. striatum 1987/i - mdr (p = 0.00362), 2369/ii - mdr (p = 0.0022) and 1961/iii - mds (p = 0.0105) strains, suggesting that this matrix protein may contribute to the interaction of different clones of this human pathogen with abiotic hydrophobic surfaces. bacterial biofilms form in association with many human activities, including food processing, transportation, public infrastructure and, most importantly, healthcare (rzhepishevska. 2013). biofilms have been found on numerous medical devices (e.g., urinary catheters, central venous catheters and endoscopes). their presence can have serious implications for immunocompromised patients and those with indwelling medical devices (brown & williams 1985, russell & russell 1995, rutala. the acquisition of the ability to form biofilms may represent a good strategy for a microorganism to acquire enhanced survival under conditions of stress, e.g., during host invasion or following antibiotic treatment, because cells growing in biofilms are highly resistant to components of the human immune system and to numerous types of antimicrobial agents. in addition, the ability of bacterial cells to transfer genes horizontally is enhanced within biofilm communities, thereby facilitating the spread of antibiotic resistance (stewart & costerton 2001, lee. our results reveal the capacities of diverse c. striatum isolates to adhere to various abiotic surfaces and to form biofilms in an in vitro catheter model. the data revealed variations among the capacities of diverse clones of mdr and mds c. striatum strains identified during a nosocomial outbreak in rj to adhere to and survive on positively and negatively charged abiotic surfaces. notably, we identified an association of increased biofilm formation, antimicrobial multiresistance and clonality of the c. striatum strains. in the present study, c. striatum mdr pfge types i and ii were predominantly isolated during the nosocomial outbreak from in - patients undergoing endotracheal intubation procedures in the icu or in surgical wards. the clinical isolates of these pfge types expressed a high capacity to form biofilms on hydrophilic (glass ; positively charged) and hydrophobic (polystyrene ; negatively charged) abiotic surfaces, including polyurethane (positively charged) catheter surfaces. the results of the semiquantitative roll - plate method and quantitative catheter culture assays showed that viable bacterial cells extensively adhered to and multiplied on the surfaces of polyurethane catheters. sem revealed a large amount of biofilm on polyurethane catheter surfaces produced by all c. striatum strains tested. the developmental biology of biofilm formation can be characterised into three stages : initial attachment, development of microcolony formation and detachment (otoole. 2000). 2009), autoaggregative c. striatum strains were able to attach to and form microcolonies (a hallmark of biofilm formation) on abiotic surfaces. c. striatum also formed matrix - enclosed microcolonies on in vitro colonised polyurethane surfaces. hollow voids indicative of mature biofilm formation on the surfaces of polyurethane catheters were also observed. the formation of hollow voids seems to be involved in the dispersion of sessile bacterial cells during the final stage of biofilm formation, which can increase bacterial virulence (rice. some bacterial properties are associated with biofilm production, including the increased synthesis of exopolysaccharides, hydrophobic properties and the development of antibiotic resistance (olson. a previous study has addressed the prevention of biofilms and has shown that the surface charge of an abiotic substrate may influence the morphology and physiology of a biofilm (rzhepishevska. the mdr and mds c. striatum strains were able to adhere at different levels to negatively charged plastic (polystyrene) and positively charged (glass) surfaces, as previously observed with c. diphtheriae and/or c. urealyticum (mattos - guaraldi & formiga 1991, mattos - guaraldi. polyurethane implanted subcutaneously into mice led to an infiltration of erythrocytes and subsequent haemolysis, possibly due to the attraction of this positively charged plastic to negatively charged cells (rigdon 1970). in accordance with previous observations of c. diphtheriae (mattos - guaraldi & formiga 1991, mattos - guaraldi. 1999a, b, gomes. 2013), the negatively charged cell surfaces of c. striatum strains and their adherence to polyurethane may be partially explained by the positive electric charge associated with this polymer. moreover, the amorphous deposited substances or glycocalyx noted surrounding c. striatum microcolonies on the surfaces of the polyurethane catheters suggest that this bacteria may produce or attract substances that strengthen their attachment to inert surfaces in vitro. hydrophobicity has been significantly associated with biofilm formation of lipophilic skin corynebacteria on solid surfaces (kwaszewska. are mainly related to biofilm formation on polystyrene surfaces (mattos - guaraldi. the cell surface hydrophobicity of c. striatum strains was demonstrated by their ability to adhere to polystyrene surfaces. therefore, c. striatum strains should be included among bacterial species that have a natural tendency to adhere to available biotic and/or abiotic surfaces and to form biofilm (olson. 2006, soriano. 2009) and that are also capable of rapid physiological responses following exposure to surfaces with varying physicochemical characteristics, enabling some bacterial colonisation on negatively charged surfaces (kwaszewska. in natural environments, bacteria typically adhere to the layer of adsorbed molecules that coats inert surfaces, the so - called conditioning film and not directly to the substratum. in vivo, any material surface is rapidly covered by plasma and matrix proteins, to which bacteria may display specific adhesins. the stimulation of bacterial biofilm formation by exogenous mammalian proteins has been reported for many human pathogens (bonifait. fbg is a major protein in human plasma and is primarily involved in the coagulation cascade system through its conversion to insoluble fibrin. fbg synthesis is dramatically upregulated during inflammation or under stress conditions, such as systemic infections. fbg and fibrin play overlapping roles in blood clotting, fibrinolysis, the inflammatory response, cellular and matrix interactions and wound healing (mosesson 2005). the fbg binding properties of staphylococcus aureus (oneill. (bonifait. 2008) and c. diphtheriae (gomes. 2010) allow them to attach to each other through fbg - mediated cross - bridging, contributing to biofilm production. the ability of c. striatum strains to bind to fbg was also demonstrated in the present study. in addition to the ability to form biofilms directly on hydrophilic and hydrophobic abiotic surfaces, c. striatum also produced biofilms on fbg - associated conditioning films. compared with the formation of biofilms on the uncoated polystyrene surfaces, the fbg - coated surfaces showed enhanced biofilm formation by the c. striatum 1987/i - mdr strain, which was responsible for a previous nosocomial outbreak. the enhancement occurred at a typical in vivo concentration of fbg in blood plasma of approximately 2.5 mg / ml. therefore, the expression of fbg - binding adhesins at different levels may be implicated in biofilm formation on conditioning films by c. striatum strains, as has been previously reported for s. suis (bonifait. c. striatum may form biofilms in vivo by an adherent biofilm mode of growth in vitro, as was demonstrated on hydrophilic and hydrophobic abiotic surfaces, including polyurethane catheters. the affinity of c. striatum for human fbg was determined to be an additional potential virulence trait of this organism. in addition to its multi - resistance to antimicrobial agents used in therapy, the ability to produce a conditioning film may contribute to the establishment and dissemination of nosocomial infections caused by this organism, including those in patients with indwelling medical devices. thus, c. striatum strains capable of forming biofilms may be selected under antibiotic pressure, or conversely, c. striatum may acquire resistance to multiple drugs within biofilm communities. in either event, the high colonising capacity of c. striatum combined with its resistance to multiple drugs will contribute to the survival and further dissemination of this organism in the hospital setting. | corynebacterium striatum is a potentially pathogenic microorganism that causes nosocomial outbreaks. however, little is known about its virulence factors that may contribute to healthcare - associated infections (hais). we investigated the biofilm production on abiotic surfaces of multidrug - resistant (mdr) and multidrug - susceptible (mds) strains of c. striatum of pulsed - field gel electrophoresis types i - mdr, ii - mdr, iii - mds and iv - mds isolated during a nosocomial outbreak in rio de janeiro, brazil. the results showed that c. striatum was able to adhere to hydrophilic and hydrophobic abiotic surfaces. the c. striatum 1987/i - mdr strain, predominantly isolated from patients undergoing endotracheal intubation procedures, showed the greatest ability to adhere to all surfaces. c. striatum bound fibrinogen to its surface, which contributed to biofilm formation. scanning electron microscopy showed the production of mature biofilms on polyurethane catheters by all pulsotypes. in conclusion, biofilm production may contribute to the establishment of hais caused by c. striatum. |
respiratory chain defects (rcd) are usually phenotypically related to heterogeneous clinical features, ranging from fatal infantile multisystem syndromes to encephalomyopathies or isolated myopathies sometimes associated with cardiomyopathies. hypotonia, lactic acidosis, cardiorespiratory failure and severe psychomotor delay are the most frequently reported features in paediatric patients, while myopathy, associated to central nervous system involvement (hearing loss, pigmentary retinopathy, seizures, ataxia, polyneuropathy, rarely movement disorders) is a main characteristic of the adult - onset pathologies. respiratory chain defects are either related to mitochondrial dna mutations, or to abnormalities in nuclear genes linked to mitochondrial function. complex i (ci, nadh dehydrogenase ubiquinone ubiquinol reductase) is the largest complex of the respiratory chain. it catalyses the transfer of electrons from nadh to coenzyme q10, and consists of 45 subunits, seven of which (nd1nd6, nd4l) encoded by the mitochondrial genome. in mitochondrial disorders, isolated ci deficiency is relatively frequent, usually associated with severe, early - onset, multisystem phenotype. due to the enzyme complexity, in almost half of the cases of ci defect, only few mutations in the mitochondrial dna (mtdna)-encoded nd2 subunit (ec:1.6.5.3) have been reported, usually associated with leigh syndrome, and leber 's hereditary optic neuropathy ; a single patient has been reported carrying a 2-bp deletion in mtnd2 gene and suffering from severe exercise intolerance. here we report a new mutation in the mtnd2 gene in a patient with a severe and isolated ci defect showing a relatively mild phenotype characterized by exercise intolerance and lactic acidosis. the patient is a 21-year - old man, the first born after uncomplicated pregnancy and delivery from healthy unrelated parents. first symptoms became evident at the age of 7 years, when he began to complain of overall fatigability presenting exclusively during physical activities, and worsened by exposure to cold temperatures. in the late five years, the exercise intolerance became so severe he could not keep up with his schoolmates when playing and running, requiring 30 to 60 min to regain the overall strength. the progressive fatigability eventually prevented him from riding a bike, then he became unable to carry ordinary burdens (i.e. backpack, books) while the tolerable walking distance gradually shortened to 150 m. neither cognitive nor behavioural changes were described ; he did not report any hearing, vision, speech impairment, he never lost consciousness, and he never experienced any selective muscle group weaknesses nor myoglobinuria. starting from the age of 17 years, he began to exhibit frequent vomiting while exercising, symptoms that urged the patient 's family to search for medical help. the first clinical evaluation performed at 20 years of age showed asthenic habitus, no dysmorphic facial features but he showed high - arched palate and malocclusion of teeth, normal head circumference, low body mass index (bmi, 18 clinical tests for myasthenia, prostigmine test, anti - achr and anti - musk antibodies were negative. however, he referred general weakness during arm uplifting > 60 s. and five squats. the psychological testing and psychiatric status were normal (full - scale iq = 97, wais - iv). electrophysiological assessment (electroencephalogram, multimodal evoked potentials, eng, emg with repetitive stimulation) and brain mri with spectroscopy were normal. thyroid status and routine blood tests for renal and liver function were within normal ranges, so as ck values (190 u / l). lactate at rest were increased in the blood (9.9 mmol / l, n.v. a) that causes the substitution of the glycine in position 121 with an aspartic acid (p.gly121asp) in the protein, in a site between two intermembrane domains. the mutation has never been reported, the p.gly121asp change scored very highly for likelihood to be deleterious according to ad - hoc softwares for pathogenicity prediction (damaging for polyphen2 : p = 1.000 ; panther : 0.96 ; mutpred : 0.969 ; sift and mutationtaster) and the amino - acid involved is highly conserved in the phylogenies (fig. pcr - rflp analysis performed to quantify the mutation in different tissues using the nlaiv enzyme (fig. 2b) showed the presence of the m.4831 g > a change in the 95% of mitochondrial genomes from patient 's muscle, in the 40% of genomes from urinary tract cells and only in < 5% of genomes from patient 's peripheral blood lymphocytes. the mutation was absent in fibroblasts obtained from skin biopsy as in the tissues (blood and urine) from the healthy mother and younger brother (fig. isolated ci deficiency is a frequent cause of mitochondrial dysfunction, usually related to severe and early - onset multisystem phenotype and associated with mutations in nuclear genes coding for ci structural proteins. we report a novel mutation in mitochondrial mtnd2 gene coding for a ci subunit, characterized by a mild phenotype with exclusive muscular involvement presented as exercise intolerance and high blood lactate at rest. vomiting while exercising might be due to frequent physiological causes or rare somatic causes, and it is often a hallmark of exercise intolerance. in our patient coenzyme q10 therapy could ameliorate the capability to endure physical activity, but was unable to treat the overall fatigability. the severe ci deficiency observed in patient 's muscle homogenate is related to the almost homoplasmic mutation in this tissue, while in fibroblasts, where the mutation was absent, the activity was normal. this evidence confirms the pathogenicity of the mutation which, by changing an amino - acid highly preserved between species that links two intermembrane domains, probably affects their stability and function. furthermore, the high mutation load on muscle tissue can explain the onset in childhood and the relatively benign course of the disease involving only skeletal muscle, but raises the question of how and when the specific tissue segregation ensued in this patient. the absence of the mutation in the healthy mother and brother suggests the exclusive presence of a lower mutation load in the ovarian cells or a de novo genesis in our patient. extreme exercise intolerance and isolated mitochondrial myopathy has been reported in mitochondrial dna mutations in at least 5 genes : mtcytb mtnd2, mtnd4, mtnd5, and trnas. our case resembles that of several mutations in mtcytb, another mtdna gene that encodes for the cytochrome b, a subunit of complex iii, which are often sporadic, in which a pure myopathy with exercise intolerance has been described,,. since now only few patients showing an exclusively mild muscular phenotype have been described carrying mutations in mtnd4 and mtnd5 genes coding for ci, and only one patient has been reported with a phenotype similar to our patient, characterized by severe exercise intolerance and lactic acidosis, due to a deletion of 2 bp in mtnd2 gene. in all this patients the muscle biopsy showed ragged - red and cox - positive fibres ; the mutations were present at high level only in muscle tissue, as seen in our patient. the accumulation of mitochondria is present in a large number of muscle fibres in particular in type 2 fibres, which show a peculiar large accumulation of mitochondria positive for cox and sdh staining that correlate with the biochemical data of a significative increment of citrate synthetase activity and a normal cox activity. nevertheless the presence of mitochondrial proliferation with enlarged organelles containing osmiophilic inclusions and abnormal cristae confirm the severe involvement of mitochondria in muscle in conclusion, in the presence of isolated exercise intolerance with high blood lactate, histopathological signs of mitochondrial myopathy and defects of ci activity, the sequence analysis of mitochondrial dna should be performed. | to date, only few mutations in the mitochondrial dna (mtdna)-encoded nd2 subunit of complex i have been reported, usually presenting a severe phenotype characterized by early onset encephalomyopathy and early death. in this report, we describe a new mutation in the mtnd2 gene in a 21-year - old man with a mild myopathic phenotype characterized by exercise intolerance and increased plasma lactate at rest. electromyography and brain nmr were normal, and no cardiac involvement was present. muscle biopsy showed a massive presence of ragged red cox - positive fibres, with enlarged mitochondria containing osmiophilic inclusions. biochemical assays revealed a severe isolated complex i deficiency. we identified a novel, heteroplasmic mutation m.4831 g > a in the mtnd2 gene, causing the p.gly121asp substitution in the nd2 protein. the mutation was present in the 95% of mitochondrial genomes from patient 's muscle tissue, at a lower level in cells from the urinary tract and at a lowest level in lymphocytes from patient 's blood ; the base substitution was absent in fibroblasts and in the tissues from proband 's healthy mother and brother. the specific skeletal muscle tissue involvement can explain the childhood - onset and the relatively benign, exclusively myopathic course of the disease. |
macroautophagy (hereafter named autophagy) is a degradation process of cytoplasmic components, including entire organelles [13 ]. autophagy starts with the presence of a single - membrane vesicle, the isolation membrane, which invaginates in order to sequester different targets into a double - membrane vesicle to form the autophagosome. mechanistically, autophagy starts with the activation of ulk1 and ulk2 proteins which were kept inactive by mtor activity [5, 6 ]. this event triggers the action of the ulk1/2-atg13-fip200-atg101 complex that allows proper relocalization of a pi3kc3 (phosphatidyl - inositol-3-kinase class iii) from microtubules to endoplasmic reticulum (er) to initiate vesicle nucleation [58 ]. the pi3kc3 complex also comprises p150, ambra 1, and beclin 1 proteins and generates phosphatidyl - inositol-3-phosphate in nucleation membrane to recruit additional autophagy - related (atg) proteins to the site of autophagosome formation. afterwards, in an ubiquitination - like process, atg12 is conjugated to atg5, and the atg12-atg5 conjugated is associated with atg16l1 which homodimerizes in a large structure named the atg16 complex. the atg16 complex associates with the autophagosomal membrane where its activity is necessary for autophagosome membrane expansion and autophagy progression. moreover, in another ubiquitination - like process, lc3 protein is cleaved by atg4 to expose a c - terminal glycine which is conjugated to phosphatidylethanolamine (pe), allowing the recruitment of lc3-pe to autophagosome membrane. autophagy was mostly considered as a mechanism allowing cells to recycle cellular component in order to generate energy during starvation conditions. however, the recent years have seen a revolution in autophagy with the demonstration that, in mammalian cells, it is a more complex and proactive system. in addition to its role during cell starvation, several reports evidenced a selective form of autophagy, capable of discriminating the target cargo for specific purposes or cellular requirements, with a clear implication in numerous human diseases [1214 ]. for instance, selective autophagic degradation of mitochondria, called mitophagy, involves selective targeting and degradation of damaged mitochondria in parkinson disease [15, 16 ]. all these exciting data about autophagy imply that it plays a role more important than expected in several human diseases, a very good reason for stepping up efforts to elucidate key autophagy mechanisms. pancreatic cancer is not an exception, with numerous reports about autophagy associated with this devastating disease. although the incidence of pancreatic adenocarcinoma (pdac) is the 10th among all cancers, it is the 4th leading cause of cancer deaths making pdac a deadly disease with a relative 1-year survival rate of only 24% and an overall 5-year survival rate of 3 to 5%. it has a highly aggressive behavior with local invasion and distant metastases during the early stages of the disease [17, 18 ]. pdac development is characterized by an almost constant sequence of gene mutations [19, 20 ]. of these mutations, the first genetic alteration observed is a gain - of - function mutation of kras which is present in nearly 100% in advanced pdacs. hence, the kras mutation is proposed as the initiating genetic lesion in pdac. moreover, homozygous deletion of the 9q21 locus is found in about 40% of tumors. through different first exons and alternative reading frames, the 9q21 locus encodes the p16 and p19 tumor suppressor proteins and therefore plays a key role in pdac progression. finally, p53 mutation and loss of smad4 are also frequently observed in the late stages of pdac development [19, 20 ]. morphologically, pdac progresses from precursor lesions named pancreas intraepithelial neoplasias (panins). panins show glandular pattern with duct - like structures and varying degrees of cellular atypia and differentiation [19, 20 ]. they are classified from grade i, with presence of columnar mucinous epithelium to grades ii and iii, with nuclear atypia. the first indication of the presence of autophagy associated with pancreas malignancy was provided in 1999 by rz and colleagues who showed images characteristic of autophagy in atypical acinar cell nodules. increased autophagic activity was observed by electron microscopy in premalignant cells, during progression of pancreatic adenocarcinoma induced in rats by azaserine and promoted by a row soya flour pancreatotrophic diet. in premalignant cells, the total volume of autophagic vesicles increases upon treatment with vinblastine, a microtubule - disruptive drug commonly used to inhibit autophagosome - lysosome fusion. interesting details are provided by fujii and colleagues who conducted a retrospective analysis of autophagy in human pancreatic tumor tissues. they observed autophagy, characterized by lc3 immunohistochemistry, in patients before the beginning of their pharmacological treatment and found a positive correlation between poor patient outcome and strong lc3 signal in the peripheral areas of pancreatic cancer suggesting that the presence of autophagy in these areas could be associated with increased cancer progression. autophagy can be induced by hypoxia, which actually occurs if vascularization is inadequate. it seems to be dependent on the hypoxia - inducible factor-1 (hif-1) which is the master transcriptional regulator of the adaptive response to hypoxia. among target genes of the transcription factor hif-1 are the genes encoding bnip3 and bnip3l, both proteins being required for hypoxia - induced autophagy. mechanistically, as beclin 1, bnip3, and bnip3l possess a bh3 domain in their structure, and it is proposed that, through that domain, they compete with beclin 1 for the interaction with bcl2 and releasing beclin 1, which induces autophagy [24, 26 ] (figure 1). in agreement with this hypothesis, pdac cells are characterized by high autophagic activity, a probable consequence of the hypoxic and starving conditions in which they are growing. conversely, the behaviour of bnip3 is characterized by a negative correlation between its expression and pancreatic cancer. interestedly, okami and colleagues demonstrated that bnip3 is silenced in pdac by gene methylation, without downregulation of other hif-1 target genes. moreover, specific bnip3 downregulation is associated with gemcitabine resistance of pancreatic cancer cells. in the work of akada and colleagues comparing pancreatic cancer cell lines sensitive or resistant to gemcitabine, they identified by cdna microarray the genes responsible for gemcitabine resistance. they showed that bnip3 expression was downregulated more than 90% in resistant cell lines and in those with intermediate sensitivity. nevertheless, microarray results indicated overexpression of bnip3 in gemcitabine - sensitive pancreatic cancer cell lines. since bnip3 is a hypoxia - inducible proapoptotic molecule, these results suggest that bnip3 may have an important function during the initial stages of pdac development, inducing autophagy and contributing to the response to hypoxia and starvation. as pancreatic cancer evolves, concomitant downregulation of bnip3 makes it necessary that autophagy is induced by alternative pathways, as described hereunder. in recent years, reactive oxygen species (ros) have gained an increased importance in tumor development. as demonstrated by denicola and colleagues, it is of vital importance for cancerous cells to keep under control their redox state. they provide evidence that several oncogenes induce the antioxidant nrf2 protein, in order to reduce ros level. indeed kras / nrf2 mice present with a significant reduction in number of panins, highly supporting that ros detoxification reduces tumorigenesis in vivo. moreover, the receptor for advanced glycation end products (rage) and ros could play a preponderant role in pdac - associated autophagy. rage is a member of the immunoglobulin superfamily implicated in ros generation [33, 34 ] and in proinflammatory response [35, 36 ]. rage is overexpressed in pdac, and it is associated with tumor resistance, proliferation, and invasiveness [3740 ]. furthermore, depletion of rage in pdac cells increases sensitivity to chemotherapeutic agents, associated with caspase-3 cleavage. on the contrary, overexpression of rage reduces apoptosis with a concomitant increase in autophagy. among ligands described for rage, the high - mobility group box 1 (hmgb1) plays a key role in pdac. hmgb1 is a chromatin - associated nuclear protein involved in chromatin remodeling and regulation, which may also participate in inflammation and tumor progression [41, 42 ]. in fact, hmgb1 is released from necrotic and inflammatory cells, acting as an extracellular signaling molecule [41, 42 ]. hmgb1 has been proposed as mediator of pancreatic tumor cell resistance to antitumoral drugs since interference rna - mediated silencing of hmgb1 makes pdac - derived cells more sensitive to the apoptotic cell death induced by melphalan treatment. the authors hypothesize that hmgb1 is released by necrotic tumor cells and enhances cell resistance by activating rage, inducing autophagy, and inhibiting apoptosis. kang and colleagues have demonstrated that pdac cells exposed to h2o2 increase rage expression in a nf - kb - dependent manner. furthermore, pdac cells show increased sensitivity to oxidative stress when rage is silenced. in the same way, autophagy is induced in pdac cells upon ascorbate treatment, but this effect is reversed by adenovirus - mediated downregulation of catalase expression [44, 45 ]. rage expression is upregulated by h2o2 treatment through a pathway inhibited by inhibitors of the nf - kb pathway such as curcumin and bay 11 - 7085, or antioxidants such as n - acetylcysteine (nac). altogether, these results implicate the nf - kb pathway in rage - mediated autophagy and reveal a direct link between ros and rage in pdac. kang and colleagues hypothesized that extracellular hmgb1, released by necrotic cells, is responsible for rage - mediated induction of autophagy in tumor cells. however, they were not able to completely inhibit that effect with an anti - hmgb1 neutralizating antibody, suggesting the presence of at least one additional mechanism of action. in fact, tang. gave evidence that endogenous hmgb1 may regulate autophagy by moving from nucleus to cytoplasm to interact with beclin 1 in place of bcl-2 [26, 47 ] (figure 2). this is supported by the fact that hmgb1 translocation is induced by rapamycin and enhanced by ros or by downregulation of superoxide dismutase. altogether, these data indicate that hmgb1 may play a double role in pdac, on one hand by activating rage in neighbour cells and, on the other hand, by interacting with beclin 1 in response to ros. although the role of ros in autophagy induction is generally accepted, the role of autophagy in pdac remains to be elucidated. several lines of investigation are based on the ideas that autophagy is detrimental to tumor cells and that several antitumoral drugs act through this mechanism. in this way, it is important to note that chemotherapeutic agents generate ros in patients. indeed, the effect of ascorbate on pdac cells is totally dependent on h2o2 generation [44, 45 ]. pardo and colleagues demonstrated in several pdac - derived cell lines the induction of vmp1-mediated autophagy in response to gemcitabine treatment. in this setting, gemcitabine - induced autophagy leads tumoral cells to apoptotic cell death. it is noteworthy that the inhibition of autophagy by 3-mehtyladenine or by knockingdown vmp1 reduces gemcitabine - induced apoptotic cell death. these results are supported by data from donadelli and colleagues who demonstrated an enhanced cytotoxic effect of gemcitabine when combined with cannabinoids, which induce ros - mediated autophagy in pancreatic tumor cells. mechanistically, cannabinoid - dependent autophagy is induced by upregulating er stress - associated genes such as p8, chop, trb3, and atf4 [5153 ]. interestingly, donadelli showed that gemcitabine treatment activates expression of both cannabinoids receptors, cb1 and cb2, in a nf - kb - dependent manner. in turn, cannabinoid treatment induces ros production, er stress, and autophagic cell death (figure 3). again, this effect is inhibited when cells are treated with the free radical scavenger nac. sulforaphane (sfn), a natural product extracted from broccoli, is able to eliminate highly resistant pdac cells. naumann and colleagues showed that sfn induces autophagy and apoptosis in several pdac - derived cells and, more interestingly, that autophagy and apoptosis, although independent from each other, are both dependent on ros generation. there is evidence suggesting that autophagy plays a role in pdac cell survival in response to cell stress induced by ros, tumor microenvironment, and antitumoral agents. for instance, the metastasis - suppressor kai1 [56, 57 ] was shown to induce autophagy in pdac cells, protecting them from apoptosis and growth inhibition. the 2-deoxy - d - glucose, a glucose analog and glycolysis inhibitor, currently under clinical evaluation as chemotherapeutic drug, reduces cellular atp and induces er stress to eventually lead to cell death [59, 60 ]. in this context, cancer cells, including pdac cells, respond to 2-deoxy - d - glucose by increasing autophagy in order to avoid er stress, rather than compensating atp depletion. moreover, yang and colleagues show that autophagy is indeed requested for tumor development [27, 61 ]. they demonstrate that tumor cells derived from pdac have a higher basal autophagy level than cell lines derived from other tumor tissues. in fact, their results suggest that autophagy is not activated to control mitochondria homeostasis but to fuel oxidative phosphorylation. however, when autophagy is blocked by chloroquine or by silencing atg5, increased ros detection is observed, indicating that autophagy may occur in response to oxidized reactive species as mentioned above. in addition, accumulation of autophagosomes and improvement of gemcitabine and 5-fluorouracile effect on pancreatic tumor cell lines were reported when they are combined with omeprazole. omeprazole is thought to interfere with lysosome homeostasis [63, 64 ] and ros formation. altogether, these results support the hypothesis that autophagy is a survival reaction in response to ros produced by antitumor drugs, leading to tumor cell resistance. recently, guo and colleagues have confirmed that ras activation promotes cellular autophagy. working with epithelial kidney cells, these authors demonstrated that constitutively active ras significantly increases basal autophagy with, however, concomitant limitation of starvation - induced autophagy. importantly, depletion of atg5 and atg7, accompanied by accumulation of p62 and ubiquitinated aggregates, reduces tumoral growth. these results indicate that the role of autophagy is not only to balance the higher metabolism of tumor cells but to buffer the higher energy demand by preserving the mitochondrial function. taking into account the role of ros in pdac, it is tempting to speculate about a yet unknown selective autophagy process able to eliminate ros and other oxidized substrates. another point that needs to be considered is the role of the autophagy in pdac stromal cells. cancer cells activate autophagy in the tumor stromal compartment via paracrine mechanisms involving oxidative stress, as recently reviewed. autophagy in stromal cells provides pdac cancer cells with a steady stream of recycled nutrients and energy - rich metabolites, which are reused by pdac cells to drive tumor growth and metastasis (figure 4).. therefore, inhibition of autophagy in the tumor stroma could stop or reverse tumor growth. this would explain the effectiveness of known autophagy inhibitors as antitumor agents, such as chloroquine and 3-methyladenine. conversely, the induction of autophagy in epithelial cancer cells would block or inhibit tumor growth. this mechanism would explain the antitumor activity of agents that activate autophagy, such as mtor inhibitors. there is little doubt that autophagy plays a relevant role in pdac development although several points remain to be clarified. many efforts have been made in order to understand the mechanism(s) involved in the relationship between autophagy and pdac, but elucidation is far from being completed. data presented in this review let us to speculate on a bivalent participation of autophagy in pdac cells. in this regard, autophagy may be a prosurvival process for tumor cells where it can fuel cell metabolism in the tumor microenvironment. however, autophagy can also be induced to reduce the oxidative stress generated by accelerated cell metabolism or chemotherapeutics treatments. on the other hand, autophagy paradox, where both inhibition and stimulation of autophagy have the same net effect, which is to inhibit tumor growth. | pancreatic adenocarcinoma (pdac) is a devastating disease with an extremely poor life expectancy and no effective treatment. autophagy is a process of degradation of cytoplasmic component capable of recycling cellular components or eliminate specific targets. the presence of autophagy in pdac has been demonstrated. however, the implicated cellular pathways are not fully understood and, more importantly, the role of autophagy in pdac is matter of intensive debate. this review summarizes recently published data in an attempt to clarify the importance of autophagy in this disease and try to reconcile apparently contradictory results. |
his family history states that his mother died of liver cirrhosis associated with the hepatitis b virus (hbv). all laboratory findings were normal, but serum hepatitis b surface antigen, hepatitis b e antigen, and hbv dna were positive. the abdominal computed tomography did not show any abnormality in the liver, but a 2.4 cm sized enhancing renal mass in the left upper pole was incidentally found. 1). a whole body isotope scan to assess for metastasis did not show any abnormal uptake. the renal mass and the enlarged lymph node were excised by robotic - assisted laparoscopic partial nephrectomy based on the preoperative impression of renal cell carcinoma, renal oncocytoma, or adenoma. microscopic pathologic examination was performed intraoperatively, and lymphoproliferative lesion with negative margins was demonstrated by a frozen section. the cut surface showed a well demarcated, white tan and solid mass measuring 2.21.8 cm in the renal parenchyma (fig. these findings were seen in the renal cortex, medulla, and the paraaortic lymph node (fig. both renal tissue and lymph node tested negative for human herpsevirus 8 (hhv-8) and epstein - barr virus infection. the levels of interleukin 6 (il-6) and erythrocyte sedimentation rate (esr) were not assessed. cd is an unusual non - neoplastic lymphoproliferative disorder which was first described as a disease entity in 1956.1 it has been called angiofollicular lymphoid hyperplasia, giant lymph node hyperplasia and angiomatous lymphoid hyperplasia in the past.5 the cause is undetermined but is most likely related to abnormal follicular dendritic cells. cd arises primarily in the mediastinum, and about 70% of the reported cases tend to be of mediastinal origin, followed by lymph nodes in the abdomen, neck, and other sites.3 retroperitoneal and pararenal localizations are very rare and cd of the kidney is extremely rare.4 to the best of our knowledge, fewer than 5 cases of cd involving the kidney that are of the localized hv type have been published in the english and japanese literature.4,6,7 from the 1980s to 2010s, cd has been reported in korea for more than 80 times. of these, fewer than 15 occurred in the retroperitoneal area and only 2 in the kidney. all renal cases of cd were pc type.8,9 our case is a hvcd involving renal parenchyma and a paraaortic lymph node simultaneously. cd has been generally subclassified based on histologic features into hv, pc, and mixed type. more recently, a plasmablastic variant has been described as a fourth subtype.3 however, its clinical significance is determined by another classification of extent that is localized or multicentric.5 nearly all cases of hv type (about 80%) and a minority of pc types (about 20%) are localized, which implies that the disorder affects a single anatomic site or a single group of lymph nodes. a localized hv type usually occurs in young people and is asymptomatic and associated with a benign clinical course. it is characterized by giant lymphoid follicles with small, regressively transformed hyalinized germinal centers and interfollicular vascular proliferation. this type has sheets of mature plasma cells in the interfollicular area and associated symptoms and laboratory abnormalities, such as anemia, fever, weight loss, night sweats, hypergammaglobulinemia, hypoalbuminemia and elevated esr. following excision of the mass, the abnormalities disappear, and the patients tend to do well overall.3 by contrast, multicentric cd (mcd) is a systemic disease with lesions of two or more separate anatomic sites.3 mcd was first proposed in 1983 by frizzera.10 recently, mcd has been defined as " a systemic disease with multiple peripheral lymphadenopathy or multiorgan involvement."10 however, another recent studies suggested that mcd is often composed of several disease entities, including idiopathic mcd and secondary mcd due to hiv infection, autoimmune disease - associated lymphadenopathy, poems (polyneuropathy, organomegaly, endocrinopathy, anasarca, m - proteins and skin lesions) syndrome, and non - hodgkin lymphomas.11 multicentric forms usually have histologic features of the pc type and only rarely of the hv type. the levels of il-6 appear to correlate with the systemic inflammatory manifestations.3 recent reports suggested that hhv-8 has a viral homologue of human il-6 in its genomic dna, and hhv-8 infection stimulates b lymphocytes to induce il-6 production. moreover, other exogenous or endogenous factors may induce il-6 secretion from b lymphocytes in hhv-8 negative cd.12 nearly all hiv - positive patients and about half of hiv - negative patients with mcd have evidence of hhv-8 infection.3 however, suda.13 reported that hhv-8 appears to be unrelated to the etiology of idiopathic mcd in japan. idiopathic mcd in japan usually exhibits a chronic disease course, and appears to be related to a negative outcome for hhv-8 infection. as above, mcd lacks a clear definition to date and there are various applications. in this regard, although our case had no significant systemic symptoms, we think it can be considered as mcd, at least from an anatomic point of view. in summary, we report a very rare case of the multicentric hvcd involving the renal parenchyma and the paraaortic lymph node at the same time. the patient presented with a renal mass without evidence of hhv-8 infection and systemic symptoms. a few cases of multicentric hvcd have been reported before,14,15 but the renal location with involvement of regional lymph node has not been reported before in korea. | castleman disease is a rare lymphoproliferative lesion that is predominantly found in the mediastinum. retroperitoneal and pararenal localizations are very rare. we describe a 36-year - old man with a hyaline vascular type of castleman disease involving renal parenchyma and a paraaortic lymph node. most reported renal castleman disease was plasma cell type with systemic symptoms. herein, we report the first korean case of the hyaline vascular type of castleman disease involving the renal parenchyma and the paraaortic lymph node simultaneously. |
spain is currently the country with the highest last month prevalence of cannabis use among those aged 1524 in europe, with consistently high figures since 2005 (17.218.6%,) and with the highest prevalence of regular (339 times within the past 12 months) and heavy (40 times or more within the past 12 months) use according to 2009/2010 hbsc (health behaviour in school - aged children,) survey of 15 - 16-year olds. a range of negative effects of regular cannabis use on adolescent health and psychosocial status have been identified, including adverse effects on psychosocial development and mental health (including developing psychotic symptoms), decrease in academic performance (which can lead to academic failure), and other negative outcomes later in life [59 ]. since 2009, cannabis as a primary drug has overtaken heroin among those requesting drug treatment for the first time in their lives in the european union. its mention as a primary drug further increased in 2010 (accounting for more than 100 000 treatment demands). in this year, 76% of reported treatment entrants aged 1519 years cited cannabis as their primary drug as did 86% of those younger than 15 years. chiefly from the perspective of planning public health interventions, like secondary / targeted drug prevention or drug treatment, there is considerable value in implementing screening instruments that are capable of detecting (probable) cannabis dependence or problematic use at the population level. population or youth surveys in several european countries have recently started to incorporate screening instruments to measure cannabis dependence or problematic cannabis use [1117 ]. in order to better understand these instruments, the european monitoring centre for drugs and drug addiction (emcdda) has recommended methodological studies. in the context of general population or school surveys, there is often shortage of space for inclusion of new items, as this may considerably increase the cost of the survey. moreover, studies confirm that well - constructed short screening scales can be strong predictors of the same results found in more lengthy instruments or interviews [19, 20 ]. there are few epidemiological studies conducted in europe to date applying psychometric scales to assess problematic forms of cannabis use in the general population of adolescents [13, 1517 ]. the aims of the present study were (1) to explore the feasibility of administration of short cannabis instruments within a wide school survey of spanish adolescents, (2) to obtain insight into the psychometric performance of cast, sds, and dsm - iv cannabis abuse criteria, (3) to find out whether the instruments identify the same groups of cannabis users by exploring their overlaps and associations of positivity on them with key variables. data collection was carried out on a sample of spanish students within a biennial national school survey conducted by the spanish national programme on drugs (dgpnsd) in 2006. the reference population for this survey was students from 7 spanish regions, selected by convenience, between the ages of 14 and 18 years who attended secondary schools. two - stage cluster sampling was used, by randomly selecting 322 schools as first stage units and 644 classrooms as second stage units. in order to select the schools, the sampling frame was firstly stratified by autonomous region (seven strata) and school type (two strata, public and private schools). 9.6% of the registered students did not attend class on the date and time of the survey. 0.2% of students refused to participate in the study. the final sample consisted of 14,589 school attendees born between 1987 and 1992. the numbers of cannabis users in the studied sample were : lifetime use n = 5002, last 12 months use n = 4089, and last 30 days use n = 2735. the participation of students in the survey was based on a passive parental consent. parents ' associations of schools, school administrations, and regional educational authorities were informed about the nature, objectives, and characteristics of the study. all selected students were informed that participation in the survey was voluntary. to ensure confidentiality, a standardized questionnaire was self - completed with paper and pencil by all of the students in the selected classrooms during a normal class (4560 minutes), in the presence of the teacher who remained at the lectern throughout. the questionnaire included questions related to sociodemographic characteristics, drug use, perception of risk of different drug use behaviours, leisure time, level of perceived availability of different psychoactive drugs, social and health - related problems, sources of information on drugs, drug use by friends and classmates, and the attitudes of parents toward drug use. frequency of cannabis use in the last 12 months and in the last 30 days was measured in categories of 0, 1, 2, 3, 4 - 5, 69, 1019, 2039, and 40 or more days (in the case of last 12 months use). alcohol bingeing in the past 30 days was defined as drinking 5 or more glasses of alcohol in one single occasion. short cannabis disorders screening instruments were sought, which have been tested in similar settings. dsm - iv cannabis abuse criteria : a 5-item instrument (corresponding to four abuse criteria), which has been incorporated in the us national survey on drugs since the year 2000 and administered in those who used the respective substance on 6 or more days in the past year. by fulfilling at least one of the four abuse criteria, a person meets the criteria for abuse, which is diagnosed in the absence of dependence (dsm - iv,). for the purpose of the present epidemiological survey, abuse criteria are used without excluding dependence cases. the severity of dependence scale (sds) : a 5-item scale that measures psychological components of dependence. it has been successfully used to assess cannabis dependence in germany, australia, and brazil [11, 25, 26 ], including adolescent populations of cannabis users, where a cut - off point of 4 for dependence was established.the cannabis abuse screening test (cast) is a 6-item scale screening for problematic forms of cannabis use, validated using dsm - iv cannabis dependence and cannabis use disorders criteria as a gold standard. it has been used successfully with teenagers, and a cutoff of 2 has recently been proposed to screen for either cannabis dependence or cannabis use disorders in this population. binary scoring procedure was used, as the resulting total score has a more intuitive interpretation, while the full scoring offers only modest measurement advantages. dsm - iv cannabis abuse criteria : a 5-item instrument (corresponding to four abuse criteria), which has been incorporated in the us national survey on drugs since the year 2000 and administered in those who used the respective substance on 6 or more days in the past year. by fulfilling at least one of the four abuse criteria, a person meets the criteria for abuse, which is diagnosed in the absence of dependence (dsm - iv,). for the purpose of the present epidemiological survey, abuse criteria are used without excluding dependence cases. the severity of dependence scale (sds) : a 5-item scale that measures psychological components of dependence. it has been successfully used to assess cannabis dependence in germany, australia, and brazil [11, 25, 26 ], including adolescent populations of cannabis users, where a cut - off point of 4 for dependence was established. the cannabis abuse screening test (cast) is a 6-item scale screening for problematic forms of cannabis use, validated using dsm - iv cannabis dependence and cannabis use disorders criteria as a gold standard. it has been used successfully with teenagers, and a cutoff of 2 has recently been proposed to screen for either cannabis dependence or cannabis use disorders in this population. binary scoring procedure was used, as the resulting total score has a more intuitive interpretation, while the full scoring offers only modest measurement advantages. see table 1 for all instruments ' items, answer options, and the respective scoring. the instruments were adapted into spanish and catalan in a process including translation, back - translation, cognitive debriefing with young cannabis users, and discussion at an expert meeting. they were placed at the end of the questionnaire and addressed only to those adolescents who had indicated that they had used cannabis in the past 12 months. the assessment frame of all three instruments was last 12 months. in the case of one missing item on a particular scale, in all analyses that included positivity on the instrument, its value was replaced by mean score of the rest of the scale items. analyses of missing items and their relationship with gender, age, and frequency of use in the past year and past month were performed using the chi - square test. an analysis of psychometric properties of the three cannabis screening instruments was carried out including item analysis. internal consistency was assessed by age, to examine possible age - related lack in response consistency. instruments ' total scores were tested for their relationship with frequency of cannabis use in the past 12 months. in this correlation analysis, averages of the above - mentioned categories were used to compute the pearson coefficient and order of these categories to compute spearman 's rho. a series of bivariate analyses (chi - square test and one - way anova) and a multinomial logistic regression analysis was run to explore the associations of being positive / negative on the different combinations of instruments (in mutually exclusive categories) with key demographic, substance use, and drug - related problems variables. of the 4089 cannabis users in the past 12 months, 3569 fully completed the cast scale, 3546 the sds scale, and 3573 the dsm - iv abuse criteria. between 10.5% and 12.3% of answers per item were missing (in most of these cases the entire scale was left blank). leaving blank a substantial number of items was associated with reporting lower frequency of cannabis use in the past 12 months and in the past 30 days (chi - square test, p < 0.001 in both cases). there were, however, 136 students who reported that they had used cannabis on at least 20 days during the past year, and their total scores of at least one scale could not be computed due to missing items. no association between the number of missing items and gender or age was found. table 1 shows results of item analysis as well as some results for the composite scores of the instruments. some items had a higher share in the total score than others : the first two items in the case of dsm - iv abuse, the third item of cast, and item 4 of sds. the importance of these items was generally confirmed by analysis of proportion positive if the item was deleted. principal components analysis revealed unidimensionality in each of the instruments with relatively high factor loadings. less than 50% of variance was explained by the first component in all cases (46 - 47%). the only item which would provide (small) improvement of alpha when deleted was item 4 of the sds scale. analysis of internal consistency by age group did not reveal a clear age - related pattern with the exception of cast, where those aged 14 showed a somewhat lower internal consistency (results not shown). at least one dsm - iv criterion for abuse was fulfilled by 28.6% (1023) of the instrument completers. 34.3% (1273) of students who completed at least five items of cast had 2 or more points and would thus be assigned possible cannabis dependence / cannabis use disorders. sds positive cases (possible dependence on cannabis) at a cutoff of 4 points or more were 16.3% (592). if only those, who used cannabis on six or more days in the past twelve months were considered for positivity, the figures would be 21.6%, 28.7%, and 11.7%, respectively. students positive on the respective instruments constituted 7.0%, 8.7%, and 4.1% of the entire sample, or 5.3, 7.2, and 2.9%, if six or more days users only were considered. sensitivity analysis was performed taking into account the 136 daily or near - daily users whose total score could not be computed due to missing items. assuming that all of these frequent users would cross the cut - off point on the respective instruments, the original range of prevalence estimates based on crossing the thresholds for positivity of the different instruments (see above) would change slightly to 2.97.9%. out of the 1708 positive on at least one instrument, most cases, 70.9%, were positive on cast criteria with 26.1% only on cast ; the second largest group, 59%, was positive on the dsm - iv abuse with 18.6% only on dsm - iv abuse. a smaller proportion, 33.4%, was positive on the sds scale with 8.2% only on sds (see figure 1). pearson correlations between the instruments ' total scores were moderate : 0.363 between dsm - iv abuse and sds, 0.456 between cast and sds, and 0.500 between cast and dsm - iv abuse (r between 0.13 and 0.25). cast total score had the highest correlation of all the instruments with frequency of cannabis use in the past twelve months (0.567 and 0.588, spearman and pearson correlation coefficient, resp.). number of fulfilled dsm - iv abuse criteria correlated with frequency of use in the past year only moderately (0.326 and 0.339, correlations in the same order), and sds 's total score correlations were the lowest (0.283 and 0.251). in bivariate analyses, there were significant associations between the mutually exclusive categories of all combinations of positivity / lack of positivity on the tested instruments and all of the following variables : years of cannabis use, gender, frequency of cannabis use in the past 30 days and in the past year, friends ' consumption of cannabis, having an accident requiring medical help in the past 12 months within 6 hours after cannabis use, being under police arrest in the past 12 months within 6 hours after cannabis use, thinking that habitual cannabis smoking causes quite some problems or a lot of problems, smoking tobacco on some days a week or more during the past month, age at survey, not going to school for two or more days in the past month, because of not feeling like to, and two or more days of alcohol bingeing in the past month and going out one or more nights per week (see table 2). in a multinomial logistic regression analysis (see table 3), those being positive only on sds were not significantly different from the referent category (negative on all instruments), with the exception of a higher proportion of those thinking that habitual cannabis use poses quite some problems or a lot of problems and a significantly higher proportion of those belonging to the youngest age group (14 - 15 years old). out of the remaining categories of instrument positivity, those categories, which contained positivity on cast (positive only on cast or in combination with sds, dsm - iv abuse or both) had the highest average number of years of cannabis use. they also had a higher prevalence of truancy, a higher prevalence of frequent cannabis use in the past month (10 or more days of use), higher, but mostly not statistically significant, prevalence of alcohol bingeing in the past month, a higher proportion of the majority (or all) friends consuming cannabis, and the highest prevalence of regular tobacco smoking in the past month (at least some days a week). students who were positive on cast also had a higher prevalence of suffering an accident requiring medical help and/or detention by police within six hours after cannabis use in the past year, but this was further strengthened if positivity on cast was combined with positivity on dsm - iv abuse. the present study confirmed that it was feasible to use short psychometric instruments for problematic forms of cannabis use in a large national probabilistic survey on substance use in spanish adolescents. even though the instruments were placed at the end of the questionnaire, 8890% of items were filled in. sensitivity analysis was performed which did not find a significant influence of missing scale results in those reporting frequent cannabis use on the overall prevalence estimate. we have studied overlap between the three instruments and found that it was relatively small (16.1%) with more than half of the respondents positive on only one instrument. this is partially due to the different concepts of problem cannabis use, which are behind the three instruments. the expected relationships in this respect would be a high overlap between dsm - iv abuse and cast (the latter designed to screen for cannabis use disorders, that is, cannabis abuse and/or cannabis dependence) and a subgroup of abuse and/or cast positive persons being identified as cannabis dependent by sds. however, this was clearly not the case. moreover, focusing only on cannabis dependence gives a result which is similar to comparing all three instruments. if we were to explore the overlap between cast and sds, both validated against gold standard representing cannabis dependence, in the present study, we would still find only 28.1% of cases identified by both instruments, while almost 60% would be positive only according to cast and 12.9% only according to sds. swift. studied three measures of cannabis dependence, among them the sds and found 56% of cases identified by all three measures. one possible explanation of low overlap between screening instruments in the present study might be the existence of different types of problematic cannabis users, with different characteristics and different kinds of problems experienced by them. another possibility is the presence of measurement bias, with varying extent in the three studied instruments. the multinomial logistic regression analysis discussed sheds some light on this possibility. according to the results of this analysis, students positive only on sds scale were similar to those who were negative on all instruments with the exception of being a younger age and more likely to think that habitual cannabis use causes quite some problems or a lot of problems. on the other hand, those groups which included positivity on cast had the longest history of cannabis use, higher prevalence of different problems, some of which were directly related to cannabis use. in this group, there was a lower proportion of girls, higher tobacco smoking, markedly higher prevalence of high frequency cannabis use in the past month, more of their friends smoked cannabis, while they thought less that habitual cannabis use caused substantial problems. dsm - iv abuse positivity has further strengthened cast 's association with such problems as being detained by the police or having an accident shortly after cannabis use. this is consistent with two abuse criteria legal problems and using the substance in physically hazardous situations and confirms concurrent validity of the instrument. fulfilling dsm - iv abuse criteria was associated less strongly than cast with history and frequency of cannabis use, and other problems potentially related to cannabis use, but more strongly than sds positivity. this suggests that the usefulness of sds in screening for problematic cannabis use in the general population of adolescents is limited, as it may identify a considerable proportion of this finding from the multinomial logistic regression analysis is further corroborated by the weak association of the scale with frequency of use in the past year an important indicator within the diagnostic approach [30, 31 ] and by the fact that item 4 of the scale (wish to stop) contributed to the total score considerably while its removal would improve the internal consistency of the instrument. this weaker performance might be associated with the concept behind the scale, namely psychological components of dependence. for example, other authors have found a response bias in adolescents in the direction of overreporting dependence, mainly its symptoms being unable to cut down and tolerance. another study suggested that substance use disorders diagnostic criteria might have different meaning for adolescents, who may experience rapid development of tolerance after initiation of use and may be confused about a question on using more or longer than intended as they typically do not foresee a limit of consumption but intend to become intoxicated. the scales administration was based on self - assessment, moreover of relatively complex concepts. the sampling frame of the present study was adolescents aged 1418 who were schooled ; 18% of this age group were estimated to be unschooled and thus outside of the sampling frame. moreover, almost 10% of the students of the selected classrooms were not attending school on the day of survey. there are associations of dropping out of school and truancy with substance use and related problems shown by numerous studies (e.g., and [16, page 172 ]). however, the analysis of psychometric properties of the explored instruments may be less biased by these factors than, for example, prevalence estimation. the placing of the screening instruments (almost at the end of the questionnaire), and, possibly, the order of their presentation may have affected the number of missing responses and/or the reliability of responses due to such factors as running out of time, or tiredness of the respondent and possibly the measures of psychometric properties of the instruments. a study comparing the effects of different orders of presentation would be necessary for clarification of this question. furthermore, as establishing clinical diagnoses was not part of this study, its findings have to be interpreted cautiously in relation to these concepts. the reported psychometric properties of the applied instruments might not be transferable to clinical or targeted samples of heavy cannabis users, owing to spectrum bias in those samples. nevertheless, it is important to know how instruments to detect problematic cannabis use perform in the general adolescent population. in conclusion, sds, cast, and dsm - iv abuse criteria have performed moderately well in the present sample, but identified largely different groups of users with only modest overlaps, even between scales validated against the same gold standard. given the fact that a researcher planning an epidemiological survey may decide to choose any of these instruments to represent a measure of problematic cannabis use, this finding may be highly relevant. while one possible explanation for these differences might be the existence of different subtypes of problematic cannabis use, measurement bias of varying extent may also play a role. the present analyses put in question the validity of the sds scale in the general adolescent population. the concept of psychological components of dependence represented by the scale may be difficult to understand for adolescent cannabis users. this may be the reason for high scoring on sds items operationalizing this concept in the youngest lower frequency users who have few cannabis - related problems and who think that habitual cannabis use causes quite some problems or a lot of problems. on the other hand, cast scale had generally strong relationship with frequency of cannabis use in the last year and other variables suggesting its concurrent validity. dsm - iv abuse was less strongly associated with intensive and long - term use, but its association with legal problems and an item indicating possible use in physically hazardous situations corroborated the validity of the instrument in relation to the concept behind it. the findings of the present study are relevant also from the broader perspective of using short, self - report - based screeners of complex, more abstract concepts in the population of adolescents in psychiatry, general practice, and clinical psychology. further research, especially qualitative, is needed to shed light on adolescents ' understanding of psychometric instruments ' items related to cannabis dependence symptoms in order to improve the ascertainment of problematic cannabis use in this population. | the aim of this study was to examine the feasibility of problem cannabis use screening instruments administration within wide school surveys, their psychometric properties, overlaps, and relationships with other variables. students from 7 spanish regions, aged 1418, who attended secondary schools were sampled by two - stage cluster sampling (net sample 14,589). standardized, anonymous questionnaire including dsm - iv cannabis abuse criteria, cannabis abuse screening test (cast), and severity of dependence scale (sds) was self - completed with paper and pencil in the selected classrooms. data was analysed using classical psychometric theory, bivariate tests, and multinomial logistic regression analysis. not responding to instruments ' items (10.512.3%) was associated with reporting less frequent cannabis use. the instruments overlapped partially, with 16.1% of positives being positive on all three. sds was more likely to identify younger users with lower frequency of use who thought habitual cannabis use posed a considerable problem. cast positivity was associated with frequent cannabis use and related problems. it is feasible to use short psychometric scales in wide school surveys, but one must carefully choose the screening instrument, as different instruments identify different groups of users. these may correspond to different types of problematic cannabis use ; however, measurement bias seems to play a role too. |
about 80% of all terrestrial plants form associations with arbuscular mycorrhizal fungi (amf) (wang and qiu 2006). these are fungal symbionts that are well known to improve plant nutritional status by enhancing the uptake of essential nutrients such as phosphorous and nitrogen and by improving the water supply through an increase in root surface area (smith and read 1997). in return, fungi receive carbon in the form of photosynthates from the plant. for both the establishment and the maintenance of the symbiotic association between plants and amf, it is essential that both partners recognize each other. these recognition processes are initiated via molecular cross - talk mediated by changes in the gene expression and production of signal compounds in both partners (harrison 2005). on the plant side, altered gene expression in the presence of amf can influence other aspects of metabolism and even result in the induction of chemical defenses (gange. a number of studies in the recent past have reported the effects of amf on plant defensive compounds, such as volatile terpenoids (akiyama and hayashi 2002 ; rapparini. 2008), essential oils (copetta. 2006 ; khaosaad.2006) and glucosinolates (vierheilig.2000). furthermore, effects of amf on salicylic acid (sa) and jasmonate dependent signaling pathways have been reported, suggesting that amf modulate plant defenses (review by pozo and azcn - aguilar 2007 and references therein). amf invasion triggers a general plant response to pathogen attack (dumas - gaudot. 2000), causing a transient accumulation of sa and activation of the sa - dependent signaling pathway at the early stages of the association. these responses then seem to be repressed once the compatibility of the symbionts is recognized (reviewed by garca - garrido and ocampo 2002). two major forms of plant anti - herbivore defenses can be distinguished : direct defenses, which are toxic to the herbivore or deter feeding, and indirect defenses, which protect the plant by attracting natural enemies of the herbivore, either parasitoids or predators. direct and indirect defenses can be constitutively expressed or induced by mechanical damage or herbivore feeding. the literature on mycorrhizal influence on direct and indirect defenses and the consequences for insect herbivores is scarce (gange. 2007 ; hartley and gange 2009), although some studies that show the effects of amf on direct defenses have been published (e.g., marak. 2002 ; fuchs and bowers 2004). a major group of indirect plant defenses are volatile organic compounds (vocs) that consist principally of green leaf volatiles (glvs) and mono- and sesquiterpenes (pichersky and gershenzon 2002 ; degenhardt.2003). herbivore - induced vocs play an important role in attracting natural enemies of insect herbivores (e.g., dicke. furthermore, herbivore - induced vocs act as both intra- and inter- plant signals, and can result in priming and induction of plant defenses (e.g. kost and heil 2006 ; frost for example, mycorrhization of artemisia annua l. with two amf species did not affect the amount of total terpenes emitted, but there were slight changes in the relative quantities of single compounds (rapparini. in addition, an unspecialized fungal root endophyte (acremonium strictum) reduced terpene emission of tomato plants with consequences for insect oviposition preference (jallow. however, no study to date has investigated how herbivore damage alters the production of defenses in amf vs. non - amf plants, even though herbivory is known to have marked effects on voc emission profiles and the levels of other defense compounds. plantago lanceolata l. is a perennial forb with a cosmopolitan distribution and commonly forms associations with a large number of amf species (johnson. the main group of secondary metabolites in p. lanceolata is the iridoid glycosides, with two dominant compounds, namely aucubin and catalpol. these compounds function as feeding and oviposition stimulants for specialized insects, and as deterrents or toxins for generalist herbivores (e.g., bowers and puttick 1988, biere. antimicrobial functions of these monoterpene derivatives also have been documented (marak.2002). the association of p. lanceolata with amf can modify plant defense properties. in a study by gange and west, the levels of the two iridoid glycosides (igs), aucubin and catalpol, increased when however, the effects of amf on other groups of defensive compounds in p. lanceolata, such as green leaf volatiles or volatile terpenoids, have not yet been documented. in this study, we investigated the effects of the arbuscular mycorrhizal fungus glomus intraradices (n.c. on p. lanceolata by focusing on two groups of compounds, igs and vocs, that typically act as direct and indirect plant defenses, respectively. in an experiment with a full factorial design, we compared voc emissions and the ig contents of amf - inoculated and non - inoculated p. lanceolata individuals after mechanical wounding and caterpillar herbivory with those of non - treated control plants. mycorrhizal fungi could influence a plant s allocation to defense in different ways : 1) altering nutritional status of the host plant : greater nutrient availability could lead to an increase in primary productivity that provides more resources for the plant to use in the biosynthesis of defensive metabolites, such as igs or vocs. on the other hand, harboring amf is no guarantee of increased productivity, since in return for nutrients, plants provide symbiotic fungi with photosynthates. if the outflow of photosynthates to the fungal symbionts is greater than the increase in productivity due to enhanced nutrient supply, there may be a net decrease in carbon supply that could lead to a decline in defense metabolism. this decline might affect the production of direct vs. indirect defenses differently depending on the relative value of these defensive strategies under different nutritional conditions. 2) altering signalling pathways : independent of plant nutritional status, the presence of microorganisms, including amf, could alter defense signalling. microbial infection generally is known to activate many types of defense responses, although mycorrhizal fungi usually elicit only attenuated responses (garca - garrido and ocampo 2002). plant, fungus and insect material seeds of p. lanceolata (rieger & hofmann, germany) were sown in trays filled with commercially available sowing soil (stender vermehrungssubstrat a210, stender, germany) that was previously autoclaved for 20 min at 121c, in order to kill potential amf propagules. p. lanceolata germinated and grew in a greenhouse (day : night temperatures 2022c:1820c, 3055% humidity, 16 h light, photosynthetically- active radiation ca. 180 mol m s). to prepare a growing medium, soil from a meadow in proximity to the greenhouse (in jena, germany) was mixed with sand in a 1:1 (w w) proportion, and autoclaved for 20 min at 121c. thereafter, 178 pots (14.4 cm diam, 1.3 l) were each filled with 300 ml of the soil - sand mixture and watered with 10 ml soil suspension (500 g fresh soil suspended in 5 l tap water, filtered through a 25 m whatman filter to exclude amf propagules) in order to allow the establishment of a new microbial community in the sterile soil mixture (schroeder and janos 2004). glomus intraradices inoculum was purchased from amykor (germany) (strain amykor1), and half of it was autoclaved for 30 min at 121c. half of the 178 pots were then inoculated with 5 g of amf vital inoculum each (mycorrhizal plants), the other half were mock inoculated with the same quantity of amf autoclaved inoculum (non - mycorrhizal the inoculum was mixed with the upper layer (34 cm) of the soil - sand mixture, and the p. lanceolata seedlings were transplanted individually into the pots. due to a thrips infestation, all plants were treated once with conserve (dow agrosciences llc, usa) (conserve 0.075 %, 0.5 l spray for all the 178 plants) 5 wk after transplantation. (lepidoptera : noctuidae) (syngenta, basel, switzerland), were reared on an artificial bean diet at 21c. the diet was prepared by mixing 1 l tap water with 1 kg beans, 18 g ascorbic acid, 10 g 4-ethylbenzoic acid, 18 g -tocopherol (7.1% in germ oil), 8 ml 3.7% formaldehyde, and 2.4 l of a 5% agar solution) at 21c. third - instar caterpillars were starved for 24 h before they were used in the experiment. experimental setup and plant treatments plants were divided between mycorrhizal and non- mycorrhizal treatments, and 15 plants of a single treatment were placed in one tray (60 40 cm). the trays were positioned on a greenhouse bench in two rows, one with mycorrhizal plants and the other without, in order to avoid cross infection of amf. tray position on the greenhouse bench was shifted weekly to control for any differences in light or temperature conditions. the experiment started 52 days after seedling transplantation and lasted for 18 d. treatment of the plants started in the evening, and was performed as follows : six to seven mycorrhizal and the same number of non - mycorrhizal plants were randomly chosen and moved separately to two different trays. plants in each tray then were divided into three groups that underwent the following treatments : group 1 mechanical wounding (mw) : young and old leaves were evenly damaged by punching ten 4 mm holes per plant with a ticket puncher. the same treatment was repeated on the following day, before the volatile collection started. group 2 herbivory (h) : six third - instar s. littoralis caterpillars per plant were allowed to feed overnight on the foliage. the foliage of both the treated and the control plants was enclosed within a cellophane bag (205 x 380 mm, unipack, germany) to prevent caterpillars from escaping. in total, 32 mycorrhizal and 32 non - mycorrhizal plants underwent the mw treatment, 29 mycorrhizal and 29 non - mycorrhizal plants underwent the h treatment, and 28 mycorrhizal and 28 non - mycorrhizal underwent the c treatment. plant volatiles volatile organic compounds emitted by p. lanceolata after herbivory, mechanical wounding, or control treatment were collected in a dynamic headspace collection system located in a growth chamber set at 20c, 55% relative humidity and 85 5 mol m s photosynthetically - active radiation. approximately 16 h after the start of the treatments (h, mw, and c), each potted plant was placed individually in a 3 l glass desiccator (schott, germany). each desiccator was tightly closed with a glass lid equipped with a valve that allowed air, which was previously purified through a charcoal filter, to enter the enclosure. the incoming air flux was adjusted to 2 0.3 l min. after being in contact with the plant, the air exited the glass cylinder through a collection trap (4 mm diam glass tube containing 30 mg super q (ars, gainesville, fl, usa), positioned in an opening in the lid. all voc collections were performed within a six - hour timeframe from around 10 am to 4 pm to minimize variation in volatile emissions due to plant diurnal rhythm. after 4 h voc collection, the super q traps were eluted with 150 l dichloromethane that contained 1500 ng nonylacetate as an internal standard. vocs were identified with a hewlett - packard model 6890 gas chromatograph employing the carrier gas he at 1 ml min, splitless injection (injection temperature : 220c, injection volume : 1 l), a db-5ms column (30 m 0.25 mm 0.25 m film, j & w scientific, folsom, usa), and a temperature program from 40c (2 min hold) to 300c (2 min hold) with a first gradient of 7c min to 155c and a second gradient of 60c min to 300c. coupled to the gas chromatograph was a mass spectrometer (hewlett - packard model 5973) with a quadrupole mass selective detector ; transfer line temperature, 270c ; ionization potential, 70 ev ; and a scan range of m / z 40350. for quantification, a gc was coupled to a fid detector operating at 250c, using the same conditions described above. vocs were first identified on the gc - ms by reference spectra in the wiley and national institute of standards and technology libraries and in the literature (joulain and knig 1998) and by comparison of retention times and mass spectra to those of standards in our collection and others kindly supplied by wilfried a. knig, hamburg (essential oils of oreodaphne porosa and aloysia sellowii). quantification of the identified compounds was carried out by comparing the peak areas in the fid traces with that of the internal standard, applying a response factor of 1 for the internal standard, 1.11 for (z)-3-hexenyl acetate, 0.75 for (e)--ocimene and (e)-4,8 dimethyl-1,3,7-nonatriene (dmnt), and 0.74 for all the sesquiterpenes (calculated according to the effective carbon number concept (scanion and willis 1985)). in addition to the 6 major compounds discussed in the results section, other compounds were identified in a subgroup of the 29 plants subjected to herbivory treatment (n = number of individuals from which the particular voc was identified) : limonene (n = 11), -copaene (n = 12), -elemene (n = 5), -humulene (n = 5), -muurolene (n = 2), -cadinene (n = 2). as the sum of these terpenoids never exceeded 7% of the total volatiles, they were not included in further analyses. plant performance after voc collection, the aboveground parts of all plants were cut at ground level, and the number of leaves and fresh weight were recorded for each plant. in order to estimate the amount of leaf area lost due to caterpillar feeding in the herbivore treatment, the leaves from these plants were aligned on a white board together with a reference area of 2.25 cm and photographed with a digital camera. digital images were analyzed with adobe photoshop (adobe systems incorporated, usa). by referring to the amount of pixels in the reference area, leaf area loss due to caterpillar feeding then was reconstructed by using the remaining leaf area as a template. after photographing, leaves of all plants iridoid glycosides iridoid glycosides were extracted from 25 mg of freeze dried, finely ground leaf material with 1.8 ml methanol. after 6 h extraction, leaf material was centrifuged at 16000 g, and the supernatant was transferred into clean tubes and evaporated to dryness under nitrogen. the pellet was redissolved in 500 l of a 20% methanol solution and centrifuged at 16000 g (modified from marak. separation of iridoid glycosides was achieved on a hewlett packard hp 1100 series hplc system with autosampler and diode - array detector. the procedure employed a c-18 reversed phase column (supelcosil lc18, 250 4.6 mm i.d., 5 m particle size, supelco) operated at 1 ml min and 25c. elution was accomplished with a gradient (solvent a : 0,05% trifluoroacetic acid, solvent b : mecn) of 015 % b (15 min), followed by a cleaning cycle (15100 % b in 0.5 min, 2.5 min hold, 100 to 0 % b in 0.1 min, 5 min hold). eluting compounds were monitored at 200 nm, and peaks were identified by match of retention time and uv spectrum with those of commercial standards (catalpol, wako chemicals ; aucubin, carl roth, germany). additionally, the identity of catalpol and aucubin was confirmed by lc - ms. concentrations of iridoid glycosides were calculated by using response curves generated with external standards of catalpol and aucubin. mycorrhization rates for the determination of mycorrhization rate, a subset of 30 mycorrhizal and 30 non - mycorrhizal plants was sampled so that an equal number of individuals from each treatment (h, mw, and c) and from each day of volatile collection were included. immediately after removal of the leaves, roots were rinsed carefully to wash off the soil, fixed in formaldehyde acetic - acid [faa : 6.0% formaldehyde, 2.3% glacial acetic acid, 45.8% ethanol and 45.9% h2o (v v) ], and stored at 4c. fixed roots were washed with distilled water, cut in segments of approximately 1.5 cm, and heated at 90c for 10 min in 10% koh. afterwards, roots were rinsed in tap water, acidified to 3.7% hcl for 10 min, and stained for 11 min in a ready - to - use lactophenol blue solution (fluka, switzerland) (phillips and hayman 1970). total mycorrhizal colonization rates (percentage of the examined root segments with mycorrhizal structures) were determined microscopically using the line intersect method (phillips and hayman 1970), modified after schmitz. (1991). stained root segments from one single plant were densely packed on a microscope slide. a minimum of 300 visual fields per slide were observed at 200 magnification. plant and soil nutrient analysis freeze dried, finely ground plant material (300 mg) and the sand - soil mixture in which the plants grew (500 mg) were analyzed for total carbon and nitrogen content with an elemental analyzer (vario max cns, elementar, hanau, germany). statistical analysis in order to analyze the influence of mycorrhization and treatments (h, mw, and c) on the amount of 1) the individual volatile compounds, 2) the total amount of terpenes, and 3) the amount of glvs emitted and corrected for the dry weight of the plants at the same time, analysis of covariance (ancova) was used. type of treatment and presence of mycorrhiza were considered as fixed factors, and dry weight was fitted in the model as a continuous covariate. data were either cube root (total terpenes and glv) or log transformed (single volatiles), and quantities equal to zero were excluded from the analysis of single volatiles to match the prerequisites for ancova. whenever possible, models were simplified by removing non - significant terms (crawley 2007). significance of differences between factor levels were tested by tukey multiple comparisons of means. as for volatiles, the influence of mycorrhization and treatments was analyzed on catalpol and aucubin levels. since igs are constitutively produced compounds known to accumulate during plant development (barton 2007), time was fitted to the model as a covariate. time was indicated as the number of days (1 to 18) from the start of the experiment, i.e., from the day of the treatment of the first set of plants. catalpol quantities were square - root transformed before analysis to fulfil the requirements for ancova. significance of differences in aboveground biomass (dry weight), leaf number, herbivory rates, and carbon and nitrogen content between mycorrhizal and non - mycorrhizal plants was tested by student s t - test. all statistical analyses were performed with software package r (r development core team (2008), r : a language and environment for statistical computing. plant volatiles plantago lanceolata plants emitted a volatile bouquet dominated by the green leaf volatile (glv), (z)-3-hexenyl acetate, as well as terpenoids of different classes. in order to assess the effect of mycorrhization and different treatments on the volatile emission of p. lanceolata, we quantified the six major volatile compounds, which together make up between 7090% of the total mixture in herbivory treated and mechanically wounded plants. these include the green leaf volatile (z)-3-hexenyl acetate, the monoterpene (e)--ocimene, the c11 homoterpene (e)-4,8-dimethyl-1,3,7-nonatriene (dmnt), and the sesquiterpenes (e)--caryophyllene, (e)--bergamotene, and (e)--farnesene. the volatile organic compound (voc) emission profile of p. lanceolata was significantly different among plants in the different treatments (fig. 1a, table 1). most strikingly, herbivore - damaged plants emitted much higher levels of terpenoids than mechanically - damaged plants or undamaged controls (fig. 1total emission of terpenes (a) and green leaf volatiles (glv) (b) from plantago lanceolata after herbivory (black bars) and mechanical wounding (light gray bars) in comparison to untreated control plants (dark grey bars). different letters indicate significant differences between the means according to ancova followed by tukey test (adjusted p < 0.05)table 1emission rate of the six major volatiles and content of the iridoid glycosides in the leaves of herbivory - treated, mechanically wounded and untreated control plantago lanceolata plantscompoundmycorrhizalnon - mycorrhizalherbivorymechanical woundingcontrolherbivorymechanical woundingcontrolvolatilesng (gdw) hr ; mean se(z)-3-hexenyl acetate376.61 97.56552.15 65.96364.37 99.6581.96 104.68376.61 71.397.19 13.59(e)--ocimene75.37 15.196.94 2.211.01 0.71103.04 17.414.06 1.100.94 0.60dmnt22.05 4.640.19 0.190.0068.65 11.710.70 0.520.00(e)--caryophyllene45.90 10.062.23 0.920.00107.69 25.830.23 0.190.65(e)--bergamotene25.84 5.031.13 0.810.0070.16 12.640.450.45(e)--farnesene31.84 8.050.88 0.610.00101.75 21.670.000.59iridoid glycosidesg (mgdw) ; mean secatalpol2.79 0.322.87 0.353.26 0.343.03 0.322.95 0.332.94 0.47aucubin7.13 0.586.61 0.546.89 0.497.35 0.516.54 0.605.37 0.54these volatiles were emitted by a single plant, therefore the se has not been calculated total emission of terpenes (a) and green leaf volatiles (glv) (b) from plantago lanceolata after herbivory (black bars) and mechanical wounding (light gray bars) in comparison to untreated control plants (dark grey bars). different letters indicate significant differences between the means according to ancova followed by tukey test (adjusted p < 0.05) emission rate of the six major volatiles and content of the iridoid glycosides in the leaves of herbivory - treated, mechanically wounded and untreated control plantago lanceolata plants these volatiles were emitted by a single plant, therefore the se has not been calculated there were significant differences between mycorrhizal and non - mycorrhizal plants. mycorrhizal plants emitted about 55% less total terpenoids compared to non - mycorrhizal plants in the herbivory treatment (mycorrhiza : f1,171 = 5.11, p = 0.039 ; interaction mycorrhiza : treatment : f2,171 = 8.14, p < 0.001 ; fig. the emission of sesquiterpenes was 63% lower in mycorrhizal compared to non - mycorrhizal plants after herbivory (table 1), but the emission of monoterpene, (e)--ocimene, was not affected by this treatment (f1,83 = 0.04, p = 0.845, table 2). 2linear regression of (z)-3-hexenyl acetate emission and plant dry weight for mycorrhizal (solid line) and non - mycorrhizal (dashed line) plants. black dots represent all mycorrhizal plants (herbivory - treated, mechanically wounded and untreated), while open dots represent all non - mycorrhizal plants (herbivory - treated, mechanically wounded and untreated) linear regression of (z)-3-hexenyl acetate emission and plant dry weight for mycorrhizal (solid line) and non - mycorrhizal (dashed line) plants. black dots represent all mycorrhizal plants (herbivory - treated, mechanically wounded and untreated), while open dots represent all non - mycorrhizal plants (herbivory - treated, mechanically wounded and untreated) for (z)-3-hexenyl acetate, the only major glv detected, mycorrhizal infection increased emission of undamaged plants more than 3-fold compared to undamaged non - mycorrhizal plants. herbivory and mechanical wounding of mycorrhizal plants caused no further increase in the emission of this glv, while these treatments did increase emission from non - mycorrhizal plants by over 5-fold (fig. the ancova showed no significant interactions between the quantity of any of the terpenes and plant dry weight. however, a significant interaction of dry weight and mycorrhization (f4,170 = 4.36, p = 0.038, table 2) was found for (z)-3-hexenyl acetate. this means that the effect of mycorrhization on glv emission varied according to plant biomass. in small plants, mycorrhization increased (z)-3-hexenyl acetate emission, while it had the opposite effect on larger plants (fig plant performance the total aboveground biomass of mycorrhizal plants was on average 8.5% lower than non - mycorrhizal plants (fresh weight : t1,175 = 3.19, p = 0.002, dry weight : t1,176 = 3.87, p < 0.001) (fig 3). this result might be attributed to a drain of fixed carbon toward the fungus in mycorrhizal plants. in fact, mycorrhizal plants contained less carbon in their leaves compared to non - mycorrhizal plants (average c% : mycorrhizal plants = 41.4%, non - mycorrhizal plants = 42.3% ; student s t - test, t1,24 = 3.98, p < 0.001), but nitrogen content did not vary between leaves of mycorrhizal and non - mycorrhizal plants (n% = 0.81% in both groups). the c / n ratio of the sand - soil mixture where the plants were grown was 23.15 0.35 (mean se, n = 4). non - mycorrhizal plants had on average a higher number of leaves compared to the mycorrhizal plants (mean non - mycorrhizal : 12.10, mean mycorrhizal : 11.40, t1,162 = 1.87, p = 0.063). fresh weight was recorded once for each plant, on the day the volatile collection was performed. black bars = mycorrhizal plants, grey bars = non - mycorrhizal plants. asterisks represent significant differences according to student s t - test (p < 0.01, p < fresh weight was recorded once for each plant, on the day the volatile collection was performed. black bars = mycorrhizal plants, grey bars = non - mycorrhizal plants. asterisks represent significant differences according to student s t - test (p < 0.01, p < the amount of leaf tissue consumed overnight was the same in mycorrhizal and non - mycorrhizal plants. iridoid glycosides the two main iridoid glycosides (igs) catalpol and aucubin did not show any significant change in quantity, either between the treatments or between mycorrhizal and non - mycorrhizal plants (catalpol : treatment : f2,173 = 0.065, p = 0.937, mycorrhiza : f1,173 = 0.021, p = 0.884 ; aucubin : treatment : f2,173 = 2.09, p = 0.127, mycorrhiza : f1,173 = 0.98, p = 0.322) (table 1). time was significant for both catalpol (f1,173 = 11.91, p < 0.001) and aucubin (f1,173 = 8.14, p = 0.005), indicating that the concentration of igs in the leaves slightly increased over time. table 2ancova summary table for the effects of mycorrhization, treatment and dry weight on the voc emission of plantago lanceolatavocfactorscovariatedf residualsmycorrhiza (df = 1)treatment (df = 2)dry weight (df = 1)fpfpfp(z)-3-hexenyl acetate2.450.11915.47<0.0011.340.242170(e)--ocimene0.040.84546.85<0.0016.780.01182dmnt7.680.0088.550.0051.200.27948(e)--caryophyllene11.200.00112.98<0.0013.000.08950(e)--bergamotene18.14<0.0011.740.1851.840.18054(e)--farnesene7.570.0081.0660.3531.190.28146bold numbers indicate significant effectsfor (z)-3-hexenyl acetate two interactions were significant : mycorrhiza x treatment (f = 8.41, p < 0.001) and mycorrhiza x dry weight (f = 4.36, p = 0.038). there was no significant interaction for any of the other volatile organic compounds ancova summary table for the effects of mycorrhization, treatment and dry weight on the voc emission of plantago lanceolata bold numbers indicate significant effects for (z)-3-hexenyl acetate two interactions were significant : mycorrhiza x treatment (f = 8.41, p < 0.001) and mycorrhiza x dry weight (f = 4.36, p = 0.038). there was no significant interaction for any of the other volatile organic compounds mycorrhization rates at the moment of harvest, all inoculated plants were infected by amf. on average, we found 68% of the root system colonized by the fungus. mycorrhizal symbiosis is known to affect many plant parameters, including chemical defense (gange. 2007 ; hartley and gange 2009). to understand fully the effects of this symbiosis on chemical defense, indirect defense is often manifested by the herbivore - induced release of volatile organic compounds (vocs) that attract herbivore enemies. the results from our study show that p. lanceolata produces a large increase in volatile terpenoids after herbivory that may serve in indirect defense. however, the association of p. lanceolata with the arbuscular mycorrhizal fungus (amf) g. intraradices significantly modifies the release of herbivore - induced vocs from the plant by reducing the emission of the three major sesquiterpenes and the c11 homoterpene, dmnt. as dmnt and sesquiterpenes are prominent components of volatile blends known to act in indirect defense (turlings.1990), amf may decrease the ability of herbivore - damaged plants to attract herbivore enemies. consistent with these results, jallow and co - workers (2008) recently reported that the inoculation of tomato plant roots with the endophytic fungus acremonium strictum lead to a reduction in total terpenoid emission. in artemisia (2008) reported that infection with different glomus species constitutively reduced the amounts of sesquiterpenes produced by undamaged plants compared to non - infected control plants. in contrast, infection had no effect on the amount of monoterpenes emitted by a. annua. these findings are consistent with our results from caterpillar - infested p. lanceolata plants where the major emitted monoterpene ((e)--ocimene) did not differ in its relative release rate between mycorrhizal and non - mycorrhizal plants. although there is as yet no evidence in the literature that amf can alter plant indirect defenses, there are reports of the effects of mycorrhization on the major direct defense compounds of p. lanceolata, the constitutively produced iridoid glycosides (igs), aucubin and catalpol. in our study, the levels of igs were unaffected by mycorrhization. in contrast, a positive effect of mycorrhization on the ig content of p. lanceolata was reported by gange and west (1994), who recorded higher levels of igs in mycorrhizal compared to non - mycorrhizal plants. the authors attributed this result to the relatively higher fixed carbon levels in the shoots of mycorrhizal plants compared to non - mycorrhizal plants, which allowed more substrate to be allocated to ig production. in contrast, no effect of mycorrhization by g. intraradices was found on the catalpol content of p. lanceolata leaves by wurst. we also observed a decrease in leaf carbon levels in the present study, and saw no increase in ig content. this finding supports the hypothesis that igs are produced in higher amounts after mycorrhization only when symbiosis leads to greater amounts of fixed carbon in the leaves. not only did we find a reduction of total leaf carbon content in mycorrhizal plants, but also the aboveground biomass of mycorrhizal plants was lower than that of non - mycorrhizal plants. although positive effects of amf on their symbionts productivity seem to be commonplace (johnson. 1997), neutral or negative effects of mycorrhization on plant growth parameters and biomass also have been documented for p. lanceolata (ayer. 1992 ; klironomos 2003 ; reynolds. 2005) and a number of other plant species (see johnson.1997 and references therein). that amf can function as carbon sinks in plants has already been documented (wurst. 2004 ; reynolds. 2005 ; ayres.2006). if the growth of the fungus limits the carbon available to the plant for its basic metabolic requirements, the association could turn from symbiosis into parasitism, a phenomenon that has been attributed by some authors to nutrient - rich substrates, low temperatures, or limiting light conditions (reviewed by smith and smith 1996, purin and rillig 2008) or to particularly high mycorrhization rates (gange. in addition, amf can be detrimental in association with particular hosts (klironomos 2003), and the predisposition of a given fungal strain to parasitism rather than symbiosis seems to be at least partially under genetic control (johnson.1997). when confronted with a non - beneficial amf association, plants might reallocate their resources among growth, defense, reproduction, and other functions. in this study of young p. lanceolata, there was a decline in growth, and a reduction in indirect defenses (volatile terpenes), but no change in the level of direct defenses (iridoid glycosides). these findings support our hypothesis that a net decrease in carbon availability caused by the fungus can cause a reduction in allocation to defense (in this case indirect defense). maintaining high levels of direct chemical defenses in early developmental stages is a strategy adopted by a number of plant species, for example arabidopsis thaliana (l.) heynh. (brown.2003) and nicotiana sylvestris spegazzini and comes (ohnmeiss and baldwin 2000). the reduction in indirect defenses observed can also be interpreted as a consequence of the general repression of defenses due to amf colonization. in the first stages of the association, amf seem to be able to modulate the defense signaling cascades in the plant, and lower the production of defense compounds (reviewed by garca - garrido and ocampo 2002). the mechanisms that underlie the induction of volatile terpene emission in p. lanceolata after biotic stresses such as herbivore feeding have not yet been elucidated. terpene biosynthesis is carried out by condensation of c5 isoprenoid units, which, in plants, can derive from two pathways : the methylerythritol phosphate (mep) pathway, considered the principal route to monoterpene production, and the mevalonate (mva) pathway, thought to be responsible for the production of sesqui- and triterpenes. the mep pathway also leads to the production of carotenoids and eventually apocarotenoids, some of which are responsible for the yellow - colored roots seen in a number of species after mycorrhization (strack. interest in the function of this yellow pigment has stimulated study of the mep pathway during mycorrhizal formation. mycorrhization enhances the transcription of genes encoding 1-deoxy - d - xylulose 5-phosphate synthase (dxs), the enzyme that catalyzes the initial step of the mep pathway in several species including medicago truncatula l., nicotiana tabacum l., zea mays l., lycopersicon esculentum mill., and triticum aestivum l. (walter.2000, 2002). an accumulation of transcripts for 1-deoxy - d - xylulose 5-phosphate reductoisomerase (dxr), the enzyme immediately downstream from dxs in the mep pathway, also has been reported in wheat roots after g. intraradices infection (walter. this amf - mediated activation of the mep pathway has not yet been examined with respect to the formation of monoterpenes, assumed to be mep pathway - derived. after mycorrhizal infection of p. lanceolata, we observed no change in volatile monoterpene emission or the accumulation of the igs, which derive from the same biosynthetic route as monoterpenes. instead, a decrease in sesquiterpenes and dmnt, assumed to be derived from the mva pathway, was detected. there are no reports in the literature on how the mevalonate pathway is altered by amf infection. the production of igs is known to be strongly dependent on plant age in p. lanceolata (fuchs and bowers 2004 ; barton 2007). in the study by gange and west (1994), who found higher levels of igs in mycorrhizal compared to non - mycorrhizal plants, igs were extracted from four - month - old plants, which had been associated with amf for 14 weeks. (2004), where the ig content did not change with mycorrhization, and in our study were harvested between 9 and 12 weeks of age with a mycorrhizal period of 7 or 10 weeks, respectively. according to fuchs and bowers (2004), the concentration of igs in p. lanceolata starts increasing 9 weeks after germination, while barton (2007) found a strong increase in constitutive levels of igs already after 6.5 weeks, and furthermore detected a positive correlation between growth rate and daily ig production. direct comparisons of our results with the literature are difficult because of differences in growing conditions and the genetic properties of the plant material. nevertheless, it seems plausible that the lack of increase in igs on mycorrhization observed in our plants is due to harvest at a relatively early developmental stage. the production of the glv (z)-3-hexenyl acetate in undamaged mycorrhizal - infected plants was comparable to that in herbivore or mechanically damaged individuals whether or not they were infected with mycorrhizae (fig 2). like many volatile terpenes, glvs have been indicated in attracting insect parasitoids (hoballah and turlings 2005 ; shiojiri.2006), and can, therefore, be considered indirect defense signals. by increasing the emission of levels of glvs in undamaged plants, this constitutively high glv emission could be a possible explanation for the enhanced attractiveness of mycorrhizal vs. non - mycorrhizal plants to herbivore parasitoids observed by guerrieri. (2004). considering the broad distribution and the importance of amf associations in terrestrial ecosystems in general (treseder and cross 2006 ; van der heijden.2008) and more specifically in agricultural systems (sawers.2008), there is a need for further studies to analyze the impacts of mycorrhizal associations on plant defense in a broad range of species and the regulatory mechanisms responsible for these changes. based on the present results, such investigations should also include an assessment of the mycorrhizal effects on the attraction of herbivore enemies. since this attraction can vary when a combination of fungal species are associated with one plant (gange. 2003), the effect of simultaneous association of different amf on plant chemical defenses should also be investigated. | arbuscular mycorrhizal fungi can strongly influence the metabolism of their host plant, but their effect on plant defense mechanisms has not yet been thoroughly investigated. we studied how the principal direct defenses (iridoid glycosides) and indirect defenses (volatile organic compounds) of plantago lanceolata l. are affected by insect herbivory and mechanical wounding. volatile compounds were collected and quantified from mycorrhizal and non - mycorrhizal p. lanceolata plants that underwent three different treatments : 1) insect herbivory, 2) mechanical wounding, or 3) no damage. the iridoids aucubin and catalpol were extracted and quantified from the same plants. emission of terpenoid volatiles was significantly higher after insect herbivory than after the other treatments. however, herbivore - damaged mycorrhizal plants emitted lower amounts of sesquiterpenes, but not monoterpenes, than herbivore - damaged non - mycorrhizal plants. in contrast, mycorrhizal infection increased the emission of the green leaf volatile (z)-3-hexenyl acetate in untreated control plants, making it comparable to emission from mechanically wounded or herbivore - damaged plants whether or not they had mycorrhizal associates. neither mycorrhization nor treatment had any influence on the levels of iridoid glycosides. thus, mycorrhizal infection did not have any effect on the levels of direct defense compounds measured in p. lanceolata. however, the large decline in herbivore - induced sesquiterpene emission may have important implications for the indirect defense potential of this species. |
osteoarthritis (oa) of the hip is a progressive disease and begins with degradation of the articular cartilage. with the development of disease improving the limp associated with oa of the hip can lead an improvement of gait efficiency and hence, quality of life2. however, an effective method for improving the limp associated with hip oa has not yet been established. one method of improving limping has focused on a walking style called nordic walking (nw), which has been used in physical therapy, and it is being increasingly used in recent years3,4,5,6,7. the effect of nw intervention has been reported8,9,10 ; however, there are only few reports on the kinematics of nw. nw was divided into japanese - style nordic walking (js nw) and european - style nordic walking (es nw) by the japan nordic walking league. the difference between js nw and es nw involves the use of the poles : in js nw, the walker plants the pole vertically on the ground, like a cane ; in contrast, in es nw, the walker thrusts each pole at a diagonal angle, creating driving force for a more active walking style. the limp of patients with hip oa also changes pelvic movements and muscle activity around the affected hip1, 11, 12. in this study, the effects of js nw on limping by adults with hip oa were examined. compared to ordinary walking (ow), js nw is associated with significantly decreased trunk movement in healthy adults13. it was our hypothesized that js nw might help to reduce the limp associated with hip oa. although the effects of js nw on trunk movements has been clarified, the effect of js nw on muscle activities around the hip joint and pelvic movements is obscure. in addition, the influence of ow, js nw, and es nw on limping associated with hip oa is not clear. thus, the purpose of this study was to focus on pelvic movements and muscle activities around the hip joints of adults with oa of the hip, and to clarify the effect of ow, js nw, and es nw on the improvement of limping. patients were excluded if they had severe metabolic, circulatory, or mental disease. ten participants were classified in to 4 stages according to the japanese orthopedic association (joa) committee on evaluation criteria. this classification is widely used in japan, and has been adopted by many studies14. the joa hip score is a common clinical criterion for evaluating hip oa in japan. the joa hip score is calculated by summing the category scores of for pain (40 points), range of motion (20 points), walking ability (20 points), and activities of daily life (20 points), with a score of 100 points indicating a perfect score. this study measured pelvic angles, muscle activities around the hip joint, stride, gait speed, and cadence. for patients with unilateral hip oa, measurements were taken on the affected side, and measurements were taken on the side with the lower joa hip score in bilateral hip oa. pelvic movements were derived from the angular velocities of tilt, obliquity, and rotation. angular velocity and acceleration were measured using a tri - axial angular accelerometer (mp - m6 - 06/400b, microstone corporation, nagano, japan). body - fixed sensors (bfss) containing gyroscopes and accelerometers were positioned at the dorsal side of the pelvis between the posterior superior iliac spines15, 16. bfs data were collected at a sample rate of 1,000 hz beginning at the same time as emg measurements. pelvic angle was determined during the stance phase on the emg measurement side in each analysis interval. the stance phase and swing phase were identified by analyzing sagittal acceleration in the anteroposterior direction of the acceleration waveform produced by the tri - axial angular accelerometer17. in addition, the stance phase and swing phase were confirmed by hip abductor emg activities. the pelvic angle was obtained by integrating the angular velocity measured by the bfs. the minimum and maximum pelvic angles of stance were measured and the maximum amplitude was calculated as the sum of the absolute values. the representative value of each participant was the average of 4 stance phases of maximum deflection. muscle activities of the rectus abdominis, spinal erector muscles, rectus femoris, gluteus maximus, gluteus medius, and tensor fasciae latae were measured using ag / agcl electrodes (blue sensor nf-50, ambu inc., ballerup, denmark), a preamplifier (dpa-11p, dia medical system inc., tokyo, japan), a / d converter (powerlab 8/30, adinstruments, dunedin, new zealand), and measurement software (labchart ver. muscle activities were determined by emg measurements during the swing phase and the stance phase in each analysis interval. the emg measurement device used a sampling frequency of 1,000 hz, and emg measurements began at the same time as bfs measurements. the electrode application sites were chosen according to the report of toshiya as follows18. the skin was cleaned with an alcohol - soaked cotton swab before attaching the electrodes in order to reduce the skin resistance. in addition, bipolar surface electrodes were placed at a 2-cm center - to - center distance. emg waveforms were band - pass filtered (20500 hz), before full - wave rectification. for each analysis interval, integrated emg (iemg) were calculated. isometric maximum voluntary contraction was measured, and the iemg were expressed as % iemg. the representative value of each participant was calculated as the average of 4 gait cycles. prior to performing each task, js nw and es nw were practiced according to the methods of the nordic walking league. the js nw method involves placement of the pole vertically near the heel of the forefoot. the es nw method involves placement of the pole diagonally near the heel of the forefoot. a load measuring device, nordic walking practice pole (takei scientific instruments, niigata city, japan), was used to define the load on the pole during the tasks. a load measuring device, nordic walking practice pole (strain amplifier tsa-110, takei scientific instruments, niigata city, japan), can set the upper and lower limits of the target load amount, and emits an audible sound when the load is within a specified range. japanese - style nordic walking (js nw) european - style nordic walking (es nw) stride was measured from the position of the toe at the start to the position of the toe at completion, and was calculated by dividing by the number of steps. gait speed was calculated by dividing the walking distance during each task by the walking time measured using a stopwatch (casio inc., each parameter was determined as the average of two performed tasks to obtain a representative value for each participant. (microsoft, seattle, wa, usa). pelvic angle, muscle activities around the hip joint, steps, gait speed, and cadence were compared among the walking styles. the study protocol was explained to all of the participants verbally and in writing, and their written consent was obtained. this study was approved by the ethical review board of the niigata university of health and welfare (approval number 17386 - 130218). there were 10 participants, including 9 women and 1 man, with a mean age of 63.3 6.5 years, height 153.3 4.4 cm, weight 53.9 8.7 kg, body mass index 22.8 3.4, leg length discrepancy 1.0 0.7 cm, and joa hip score 78.4 8.8. six patients with bilateral involvement had a surgical history of bilateral total hip arthroplasty (tha), and 2 patients with bilateral involvement had undergone unilateral tha because the non - tha side was end - stage oa. two patients with unilateral oa had a surgical history of unilateral tha and end - stage oa. the pelvic rotation angle was significantly larger in es nw (17.5 6.7) than in js nw (14.6 6.8) (p jsrectus femorisstance phase22.3 15.425.2 20.025.7 19.9swing phase17.5 12.318.6 14.621.2 18.8gluteus maximusstance phase47.0 18.8 33.8 12.343.4 17.3ow > js, es > jsswing phase16.5 6.316.1 5.417.0 > js, ow > esswing phase22.8 12.224.5 12.425.7 13.5tensor fasciae latae stance phase40.5 28.1 31.0 25.7 32.3 24.3ow > jsswing phase15.2 9.315.7 10.217.8 p<0.05 ; significant difference, ow vs. js.p<0.05 ; significant difference, ow vs. es. gluteus medius activity was significantly lower in both js nw (41.3 22.0%) and es nw (45.0 22.4%) than in ow (55.0 25.1%) (both p < 0.001, table 2). tensor fasciae latae activity was significantly decreased in js nw (31.0 25.7%) compared with that in ow (40.5 28.1%) (p < 0.021, table 2). p<0.05 ; significant difference, js vs. es. in the swing phase, rectus abdominis muscle activity was significantly increased in both js nw (19.7 9.6%) and es nw (19.3 9.2%) compared with that in ow (15.9 9.7%) (all p < 0.010, table 2). lumbar erector spinae activity was significantly lower in js nw (32.0 17.8%) than in ow (38.1 20.3%) (p < 0.005, table 2). stride distance was significantly larger in es nw (39.2 3.4%) than in ow (37.9 3.4%) (p < 0.015, table 3table 3.stride, gait speed, and cadence according to walking stylestride, gait speed, cadenceowjsesanalysis of variancetukey - kramerstride (%) 37.9 3.438.6 3.839.2 3.4ow < esgait speed (cm / sec)79.5 18.075.4 22.378.5 23.0cadence (step / sec) 1.3 0.21.2 0.21.2 0.2values are shown as the meansd. p<0.05 ; significant difference, ow vs. es.). there were no significant differences among the walking styles in gait speed (p = 0.247) or cadence (p = 0.066) (table 3). this study analyzed pelvic angle, muscular activities around the hip joint, and several gait parameters of three different gait styles (js nw, es nw and ow), and found there are biomechanical and physiological differences among the walking styles. although the number of participants was small, the pathological condition of each participant was not consistent, the results of this study indicate that js nw decreases compensatory pelvic rotation, protects the hip joint by decreasing the muscle activity of the hip abductors, and inhibits overused low back muscles. therefore, the js nw style might be an effective clinical intervention for improving the limp of patients with hip oa. although no significant differences in pelvic angle (tilt, obliquity, and rotation) were noted between ow and js nw or es nw, the pelvic rotation angle was significantly increased in es nw compared with that in js nw. the pelvic rotation angle increased due to the difference in pole use during nw. the two methods of nw are fundamentally different walking styles : in js nw, the pole is used vertically like a cane, whereas in es nw, the pole is thrust into the ground diagonally. according to elhtman, the body s balance during gait is controlled by the rotation of the upper extremities and trunk on the side opposite to pelvic rotation19. because of the difference in the position of the pole during ground contact, es nw is considered to be a gait style in which propulsion is acquired by large arm swings. it is clear that the driving force of es nw was derived from the use of the pole. in the analysis of muscle activities in the stance phase, the hip abductor muscles were found to have significantly lower activities in js nw than in ow or es. once again, lower hip abductor muscle activity could be attributed to the walking style of js nw, which involves planting the pole on the ground like a cane. the js nw pole placement elicits a ground reaction force, which complements the activity of the hip abductors, thereby decreasing hip abductor muscle activity20. in contrast, in es nw, only the activity of the gluteus medius was decreased. during es nw, the pole is thrust diagonally backwards ; therefore, compared with js nw, the ground reaction force of es nw moment in the vertical direction is lower. thus, only the activity of the gluteus medius was decreased. during the swing phase, rectus abdominis activity increased significantly in both js nw and es nw compared with that in ow. a ground reaction force generated by the poke of a cane was reported by neumann20, and it is conceivable that the use of pole in nw also creates a ground reaction force. in the case of additional ground reaction force generated by poking the pole, a perturbation force may act on the trunk due to the diagonal force generated from the ground toward the center of gravity. therefore, there is a demand to maintain the center of gravity of the body against the ground reaction force, which is generated by the use of the pole. hodges reported that the activity of the rectus abdominis muscle acts to control body sway21. it is thought that rectus abdominis muscle activity increases to control the center of gravity with respect to the ground reaction force due to the use of the pole. in addition, the lumbar erector spinae activity was significantly lower in js nw than in ow. an increase in abdominal rectus muscle activity leads to an increase in intra - abdominal pressure, which increases trunk stability22. in addition, an increase of trunk stabilization results in a decrease of back muscles activity. the hypothesis of this study was that js nw would have an influence to pelvic movements and improve the limping of those with oa of the hip. in general, flexion in oa hips during gait is limited due to rom restriction, and compensatory pelvic rotation is increased at the time of walking. this is considered to lead a reduction in compensatory pelvic rotation in the patients with hip oa, which indicates improvement of limping. with regard to muscle activity, hip abductor muscle activity reduced, rectus abdominis activity increased, and lumbar erector spine activity decreased during js nw. the hip abductors are significantly involved in the generation of joint compression force, so js nw, which decreases the activity of the hip abductors, might be able to protect the joint. lumbar spine disease often occur in patients with oa of the hip with corresponding low back pain23,24,25. one of the causes of low back pain is overactive low back muscle activity. in js nw, the activity of the rectus abdominis increases, since the activity of lumbar erector spine decreases. js nw might be a walking style suitable for the prevention of secondary disorders such as low back pain, because of the change in trunk muscular activity. although excessive exercise can trigger pain, exercise therapy is necessary in pain - free movement. the results of this study indicate that the js nw style offers better joint protection and trunk stability compared to ow and es nw. therefore, js nw is suggested as a walking style that can prevent hip and low back pain, and may be an effective exercise therapy for the prevention of disability in patients with hip oa. the present study demonstrated only the immediate effect of walking styles on the hip ; hence, a study with a longer treatment period is needed to verify our findings. however, the findings are significant, since a beneficial effect was confirmed in hip oa patients, despite the small sample size. | [purpose ] increased compensatory pelvic movement is remarkable in limping patients with hip osteoarthritis (oa). however, a method of improving limping has not been established. the purpose of this study was to identify the effects of two types of nordic walking by analyzing the pelvic movement and muscle activities of adults with hip oa. [subjects and methods ] ten patients with oa of the hip performed japanese - style nordic walking (js nw), european - style nordic walking (es nw), and ordinary walking (ow), and the muscle activities around the hip joint and pelvic movements were analyzed. [results ] the pelvic rotation angle was significantly larger in es nw than in js nw. in the stance phase, hip abductor muscle activity was significantly decreased in js nw compared to both ow and es nw. in the swing phase, rectus abdominis muscle activity was significantly increased in both js nw and es nw compared to ow and lumbar erector spinae activity was significantly lower in js nw than in ow. [conclusion ] js nw style may reduce the compensatory pelvic rotation in patients with hip oa. js nw might be better for joint protection and prevention of secondary disorders of the hip in oa patients. |
the current dialytic therapy has brought brilliant success in prolonging patient survival in end - stage renal disease (esrd). in addition to the control of uremia, it can prevent patients from extracellular volume (ecv) excess, dilutional hyponatremia, severe hyperkalemia and metabolic acidosis. however, it can not keep patients in a steady state all the time because of its incomplete therapeutic efficacy. the concept of stability of the ' milieu interieur (internal environment) ' was created by claude bernard in the middle of the 19 century, and it was developed to the concept of homeostasis by walter cannon and popularized in his book the wisdom of the body, published in 1932. whereas normal kidneys contribute to maintaining milieu interieur in a steady state, the current routine dialytic treatment hardly offers esrd patients homeostasis. sodium is accumulated over the interdialytic period, and sodium removal by dialysis may be insufficient because of the brief and discontinuous nature of routine dialytic therapy. besides, supraphysiologic dialysate sodium concentrations which are frequently used in current practice may hamper normalizing sodium balance in hemodialysis patients. carl kjellstrand and his associates for the first time drew attention to the issue of possible negative effects of the unphysiology of intermittent dialysis treatment1). they formulated the " unphysiology hypothesis " which stated that side effects seemed particularly common in patients who experience great swings in body weight, urea (osmolality), and potassium (k), and who had - as a consequence of their large fluid load - severe hypertension. in other words, the more " unphysiologic " dialysis is, and the more abnormal blood chemistries and fluid levels are before dialysis, the more violently they will change during dialysis and the more ill - effects those patients will experience. the best way which they contemplated to get rid of " unphysiology " was to dialyze often - i.e., dialyze daily. keeping blood chemistries within normal limits may be impossible with three dialyses per week. before each dialysis the patient would be fluid - overloaded, hyperkalemic, and acidotic. thus the patient 's body is never in a normal state ; it is in an abnormal state, both before and after dialysis2). lopot and vlek proposed two parameters for quantification of dialysis unphysiology : plasma urea time - averaged concentration (tac) and time average deviation (tad)3). the less frequent and thus less physiological the dialysis schedule, the higher will be the fluctuation of the plasma urea concentration and the higher the resulting tad. treatment outcome of a specific treatment schedule can be represented by a point on the tac / tad plot. 1 shows the tac / tad plot representing currently used renal replacement therapies and health. it was derived from an average patient with total body water of 42 l, negligible residual renal function and a protein catabolic rate (pcr) of 1 g / kg / day dialyzed with a urea clearance of 160 ml / min for the same total weekly time (and thus, equal to weekly cleared volume)3). in hemodialysis patients without residual renal function, intradialytic sodium removal should be matched with interdialytic sodium accumulation. sodium removal during hemodialysis is carried out by convection and to a lesser degree by diffusion. however, with supraphysiologic dialysate sodium concentrations, diffusive influx from dialysate may occur, especially in patients with low predialytic plasma sodium concentrations5). over the interdialytic period the ecv changes occurring in the usual thrice weekly hemodialysis treatment are shown in fig. owing to the intermittent nature of hemodialysis, the patient oscillates between a high - weight " wet " state just before the session, and a low weight " dry " state just at the end of the session6). thus, we can say that the intermittent hemodialysis is " unphysiologic " in terms of sodium balance as well. the discontinuous nature of hemodialysis causes saw - tooth volume fluctuations, and the ecv expansion during the interdialytic period may lead to hypertension and adverse cardiovascular consequences. sodium ions (na) may be divided into osmotically active and osmotically inactive fractions7). the traditional view is that na and its accompanying anions are the principal extracellular osmoles and act to hold water in the extracellular space ; conversely, k salts account for almost all the intracellular osmoles and act to hold water within the cells. although the cell membrane is permeable to both na and k, these ions are able to act as effective osmoles because they are restricted to their respective compartments by the activity of the na, k - atpase pump in the cell membrane8). thus, this fraction of na is osmotically active because na accumulation inevitably leads to water retention in the extracellular space (fig. as shown originally by short - term isotope dilution studies done by edelman.9), changes in the serum na concentration reflect short - term changes in the exchangeable fraction of total body na and k relative to total body water. more recent data have suggested that large amounts of na can be accumulated without accompanying water retention10, 11). thus, plasma and extracellular water can not be the only sites of na and water metabolism, and tissues such as bone, cartilage and connective tissue may account for > 50% of the total body na content. some osmotically inactive na in the crystalline phase of bone was postulated in the 1960s12). this localization may be interpreted as " an internal na escape into extracellular matrix components " to maintain the ecv despite a positive na balance7). if this na was bound in a " third " sodium space to negatively charged interstitial matrix components with polyanionic character or to the bone mineral, this bound na would not readily equilibrate with the ecv (water - free na accumulation) and thus would be osmotically inactive (fig. however, this osmotically inactive na can be mobilized and made available for exchange13). recently, osmotically inactive sodium storage has been documented in humans11) and rats consuming a high - salt diet14). in patients with chronic renal failure, the blood pressure (bp), when related to urinary sodium excretion, rises exponentially with the decrease of creatinine clearance15). intravascular volume - to - extracellular volume ratio increases more in patients with advanced renal insufficiency, and bp increases more in relation to the increase of ecv in these patients. the following guyton 's 2 examples show how, in the long run, small volume increases are associated with high bp increases16). the first relates to changes in fluid volume and bp caused by hyperaldosteronism in humans. in one study, after hypertension was completely controlled by spironolactone, the drug was withheld for several weeks. during the next 2 weeks, extracellular fluid volume and bp increased by 20% to 40%. during the following 2 weeks, the ecv decreased toward normal, but bp remained elevated. yet no other cause for the elevated bp was found in these patients, except for the small increase in fluid volume. another example was a study on circulatory system variables, after acute volume loading in dogs with reduced kidney mass to 30%. the study showed, within 2 days, an increased extracellular fluid and blood volume, increased cardiac output, slight decrease in total peripheral resistance, and a rise in bp. within the following few days, extracellular and blood volumes and cardiac output decreased ; however, total peripheral resistance increased and bp remained elevated (fig. guyton postulated that the bp remained elevated by increased total peripheral resistance due to autoregulation of blood flow at the tissue level16). recently, however, the mechanisms leading to vasoconstriction in salt - dependent hypertension are being understood more clearly. either excessive sodium intake or sodium retention by the kidneys and the consequent tendency toward plasma volume expansion lead to release of endogenous ouabain (eo) probably from the hypothalamus18). the na, k - atpase pumps in the vascular smooth muscle cells (vsmcs) are inhibited by the increase in plasma eo, resulting in the elevation of local na on the submembrane area. this produces electrogenic depolarization of vsmcs and facilitates ca entry through the na / ca exchanger. the resulting rise in the cytosolic ca previous clinical observations revealed that the bp response to ecv reduction was delayed by some weeks. this represents the lag phenomenon, i.e., the delay of bp decrease after normalization of extracellular fluid volume17). it was first described in the middle of the twentieth century after introduction of the " rice diet"20, 21) and during treatment with thiazide diuretics22). in 1967, scribner commented that " in many patients a time lag exists between reduction of ecv and adequate control of bp. several days or weeks may be required for adequate control, even though striking weight loss and, presumably, reduction of ecv occurred immediately."23) the time - dependent relationship between the ecv control by hemodialysis and the normalization of bp can be illustrated by the first year of dialysis of 712 patients started on hemodialysis in tassin, france24). during the first month, ecv expressed by the postdialysis weight declined sharply by 2 to 3 kg. predialysis mean arterial pressure also decreased rapidly. at 2 months, the postdialysis weight was stable, but bp continued to decrease. at that stage, antihypertensive medication was already stopped in almost all patients. between 3 and 12 months, the curves crossed over, bp continued to decrease gently, but weight increased by several kilograms (fig. 5). this gain in weight after 2 months was not related with an ecv increase but with the anabolic gain in lean and fat body mass following the start of dialysis25). first, vascular remodeling26), followed by a progressive reduction of peripheral resistances, is conceivable. secondly, vasoactive middle molecular substances such as asymmetric dimethylarginine may be very slowly removed27). thirdly, water - free sodium storage in the vsmcs may be very slowly relieved because of the restored na, k - atpase activity. specifically, the liberalization of diet and short dialysis with a high sodium concentration in the dialysate are the main causes of positive sodium balance28). according to the national survey performed in 2005, the average dietary sodium intake in koreans was estimated to be 5.2 grams per day. educating patients to restrict sodium intake < 2 grams per day thus, reducing dietary sodium intake remains the most important tool in improving bp control in dialysis patients5), and a low - salt diet is more than ever a necessity in conventional hemodialysis29). sodium removal can be increased both by applying higher ultrafiltration volumes and by lowering dialysate sodium concentration5). however, the former may be difficult because of improper tolerance, and the latter may hamper the hemodynamic stability during the dialysis. the ultrafiltration rate is a major limiting factor because intravascular compartment refilling from the interstitium needs more time than is available with now - standard short sessions29). thus, prolonging session length (long hemodialysis) will be desirable to improve hemodialysis tolerance while maintaining a high rate of ultrafiltration. current hemodialysis practices adopt a standard dialysate sodium prescription that is typically higher than the plasma sodium concentration of most patients. however, hypertonic dialysate sodium prescriptions, including sodium modeling, predispose to positive sodium balance and lead to higher bp and increased interdialytic weight gain6). conversely, lowering or individualizing dialysate sodium reduces thirst, interdialytic weight gain, and bp in non - hypotension prone dialysis patients30). a random reduction of 3 meq / l in dialysate sodium was well tolerated even by patients with preexisting hypotension31), and the sodium concentration in the dialysate may be reduced to < 138 meq / l28). it has become possible to individualize dialysate sodium concentration by means of online measurements of plasma conductivity and adjustment of dialysate conductivity by feedback technologies. sodium, which is accumulated over the interdialytic period in esrd patients, may be divided into two fractions. the one is the fraction of osmotically active sodium which is mainly confined to the extracellular space, and the other is that of water - free (osmotically inactive) sodium which diffuses into the intracellular space. both contribute to the pathogenesis of hypertension because the former may act to expand extracellular fluid volume and the latter may cause vasoconstriction in the long run by increasing cytosolic concentration of calcium in the vascular smooth muscle cells (fig., it may take several weeks to months for water - free sodium storage in the vascular smooth muscle cells to be relieved. this may be an explanation for the lag phenomenon, i.e., the delay of blood pressure decrease after normalization of extracellular fluid volume shown in the tassin experience. modest restriction of dietary sodium intake, the dialytic session length long enough to maintain a high ultrafiltration volume, and the reasonably low dialysate sodium concentration are required to avoid unphysiology of positive sodium balance in current hemodialysis practice. | dialysis unphysiology was first discussed by carl kjellstrand in 1975 for the possible negative effects of the unphysiology of intermittent dialysis treatment. current hemodialysis practices are still unphysiologic because they can not keep blood chemistries within normal limits, both before and after dialysis. in addition, the discontinuous nature of hemodialysis causes saw - tooth volume fluctuations, and the extracellular fluid volume expansion during the interdialytic period may lead to hypertension and adverse cardiovascular consequences. sodium, which is accumulated over the interdialytic period, may be divided into two fractions. the one is the fraction of osmotically active sodium which is mainly confined to the extracellular space, and the other is that of water - free (osmotically inactive) sodium which diffuses into the intracellular space. both contribute to the pathogenesis of hypertension because the former may act to expand extracellular fluid volume and the latter may cause vasoconstriction in the long run by increasing cytosolic concentration of calcium in the vascular smooth muscle cells. even in intensive hemodialysis, it may take several weeks to months for water - free sodium storage in the vascular smooth muscle cells to be relieved. this may be an explanation for the lag phenomenon, i.e., the delay of blood pressure decrease after normalization of extracellular fluid volume shown in the tassin experience. modest restriction of dietary sodium intake, the dialytic session length long enough to maintain a high ultrafiltration volume, and the reasonably low dialysate sodium concentration are required to avoid unphysiology of positive sodium balance in current hemodialysis practice. |
most visual disorders occur in the retina, which is a part of the central nervous system (cns) and consists of neurons, glia, pigment epithelium (rpe), and blood vessels. currently, diabetic retinopathy (dr), age - related macular degeneration (amd), and glaucoma are the top causes of blindness in the developed countries. these diseases can occur when local or systemic neuronal and vascular homeostasis mechanisms are dysregulated. the highest risk factor for many of these diseases is aging [13 ], and as is the case with other age - related diseases such as alzheimer 's disease, cardiovascular disease, cancer, arthritis, osteoporosis, and hypertension, accumulating evidence suggests that chronic inflammation and oxidative stress can accelerate or promote disease progression [46 ]. the renin - angiotensin system (ras) is classically known as a systemic blood - pressure - regulating system. independent of systemic ras, tissue intrinsic rass have been identified in various tissues (including the retina) and are important for maintaining local homeostasis. elements of the ras pathway are highly conserved in many species including invertebrates and humans demonstrating that its functions are evolutionarily conserved, although spatial expression patterns differ slightly between different species. we have reported that angiotensin ii type 1 receptor blocker (arb) suppresses retinal neural dysfunction in animal models of acute inflammation or diabetes. other groups and our own have also reported that arbs can protect retinal vascular inflammation [1019 ] and neuronal apoptosis [2023 ]. furthermore, it was recently reported by two independent groups that daily oral administration of arb may prevent the progression of diabetic retinopathy in randomized multicenter clinical trials [2426 ]. in this paper we will summarize these findings and other studies demonstrating that ras modulation may prevent ocular pathogenesis. lastly, we will describe the potential mechanisms through which ras inhibition may preserve neuronal function and viability while combating ocular diseases. it was later found to induce the release of a vasoconstrictive agent in experimental models of hypertension induced by renal ischemia. two independent groups identified the end product of this hypertensive cascade in 1939 and named it hypertension or the ras pathway as we know it today began to take shape once angiotensin - converting enzyme (ace) was identified in 1956. we now know that once renin is proteolytically processed from its precursor prorenin by proteases and released from the kidney, it converts angiotensinogen to angiotensin i in the liver. angiotensin i is finally converted to angiotensin ii by ace which is predominantly expressed in vascular endothelial cells (ecs) and is located in highly vascularized tissues such as the lung (figure 1). angiotensin ii stimulates vascular smooth muscle cells (vsmcs) that line endothelial cells to contract and induce vasoconstriction. there are two primary receptors for angiotensin ii : angiotensin ii type 1 receptor (at1r) and at2r ; at1r appears to exert predominant functions in blood vessels. however, the roles of at1r and at2r in pathophysiological conditions are currently under debate [3234 ]. at1r is a seven - transmembrane g protein - coupled receptor [35, 36 ]. once stimulated in vsmcs g proteins activate phospholipase c (plc) and inositol-1,4,5-triphosphate (ip3) to open calcium channels in the endoplasmic reticulum. as a result, increase of cytosolic calcium induces phosphorylation of myosin light chain, vsmc contraction, and vasoconstriction [38, 39 ]. independent of systemically circulating angiotensin ii (circulating ras), most ras components, including ace, were also found to be locally expressed in many tissues. this observation resulted in the hypothesis that in addition to being converted in particular organs for systemic circulation, angiotensin ii could also be synthesized in peripheral tissues (tissue ras) where it would exert its effect locally. tissue ras elements were identified in various organs including heart, kidney, adrenal gland, brain, and retina (see details below). an important molecule involved with tissue ras is (pro)renin receptor which interacts with prorenin to exert enzymatic activity of renin without the conventional proteolysis of the prorenin prosegment [45, 46 ]. (pro)renin receptor can be detected in major organs but not in circulation indicating that this molecule may play a critical role in the activation of tissue ras. thus tissue ras may be important for fine - tuning global ras activity or for acting intrinsically to respond to localized insults. however, (pro)renin receptor may also function independent of renin activation as a member of the wnt receptor complex to regulate wnt / - catenin pathway activity. in addition to its critical physiological functions, ras dysregulation can lead to pathogenesis. in various cardiovascular cell - type rass hyperactivation can induce pathogenic cell migration, hypertrophy, fibrosis, disrupt cell adhesion and ectopic extracellular matrix (ecm) deposition. at1r signaling directly activates key signaling pathways for cell growth and hypertrophy including jak / stat (janus kinase / signal transducer and activator of transcription) [48, 49 ], erk (extracellular - signal - regulated kinase) 1/2 [5052 ], and p38 mapk (mitogen - activated protein kinase). indeed, angiotensin ii / at1r signaling can potentiate oxidative stresses and inflammatory responses by activation of nad(p)h (nicotinamide adenine dinucleotide phosphate) oxidases [5457 ]. angiotensin ii can also activate egfr (epidermal growth factor receptors) and induces fibronectin synthesis and tgf (transforming growth factor beta) activity to promote fibrosis and ecm formation [58, 59 ]. at1r signaling can activate nfb (nuclear factor kappa - light - chain - enhancer of activated b cells) [6062 ] and ap-1 (activator protein 1) to initiate transcription of multiple proinflammatory genes [61, 63, 64 ]. at1r also induces accumulation, adhesion, and infiltration of inflammatory cells via activation of pai-1 (plasminogen activator inhibitor-1) and mcp-1 (monocyte chemotactic protein-1) to promote atherosclerosis. taken together, these findings provide strong evidence that ras is not just a regulator of blood pressure, but also regulates an inflammatory cascade. after the first ace inhibitor (acei) was developed, many other ras inhibitors including arb [68, 69 ] have been established and approved for commercial use as hypertension drugs (figure 1). ras inhibition not only prevents hypertension but also protects tissues against injury by limiting the potency of deleterious inflammatory responses. since aging is considered to be, in part, the result of chronic inflammation, it may not be too surprising that the use of ras inhibitors or genetic deletion of at1r has potential to extend the life span in hypertensive [7173 ] or normotensive mammals. in addition to regulating vasoconstriction, another important physiological function of ras is osmoregulation in the cns (e.g., water and sodium intake, sympathetic activity, and release of vasopressin) [7577 ]. at1r is expressed in brain neurons and mediates osmoregulation by stimulating the release of vasopressin in the pituitary gland and signaling the kidney to conserve water. furthermore angiotensin ii / at1r signaling in the brain forces individuals to stimulate increased thirst and consume more drinking water. since angiotensin ii has a high molecular weight, it does not cross the blood - brain barrier (bbb). additionally, every component of the ras pathway including angiotensinogen, ace, and angiotensin ii receptors is expressed in the brain [75, 76, 7981 ]. brain ras can also become dysregulated ; this has been shown to induce oxidative stress and inflammation. however, ras inhibitors have neuroprotective effects in brain inflammation and ischemia without inducing antihypertension (see detail below)., prorenin protein and renin activity can be detected in the vitreous fluid [8385 ] and prorenin mrna has been detected in muller glia and in the ciliary body (cb) cells. (pro)renin receptor is expressed in ecs, muller glia, and retinal ganglion cells (rgcs) [88, 89 ]. ace is synthesized in the neural retina [93, 94 ] and can be detected in rgcs, photoreceptors, and muller glia. angiotensin ii, the final product of ras, can be detected in the vitreous fluid and in the neural retina. interestingly, the normal concentration of angiotensin ii in ocular fluid is higher than in plasma, confirming the existence of tissue ras in the eye. in the retina, angiotensin ii receptors are detected both in ecs and in neuronal cells, which are located outside and inside of the blood - retina barrier (brb), respectively [8, 92, 99, 100 ]. at1r is found in the presynaptic terminals of photoreceptors and of interneurons in the retina as well as in neurons of the brain [101, 102 ] (figure 2). at1r is also expressed in rgcs, although the physiological function of at1r in the neural retina is not fully understood. systemic administration of acei negatively influences cat and human neural functions measured by electroretinograms (erg) in both systemic blood - pressure - dependent and -independent manners [105, 106 ] at2r is also expressed in the retina but much less is known how it functions in the eye. polymorphisms in the at2r gene may be linked to glaucoma or diameter of the retinal arterioles. increasing evidence suggests that ras activity and inflammation may be associated with various ocular diseases, and, therefore, ras inhibitors may be effective therapeutic agents. several lines of evidences suggest that ras inhibition is an effective treatment for uveitis [8, 12, 17, 18, 88 ]. endotoxin - induced uveitis (eiu) is induced with intraperitoneal injections of lipopolysaccharide (lps) ; this results in upregulated expression of proinflammatory and adhesion molecules such as icam-1 (intercellular adhesion molecule 1), mcp-1, il-6 (interleukin 6), and ifn- (interferon - gamma) [17, 88 ]. these molecules are also upregulated in experimental autoimmune uveoretinitis (eau) models generated by immunizing animals with interphotoreceptor retinoid - binding protein (irbp). the upregulation of these molecules, however, can be inhibited with arb or (pro)renin receptor blocker (prrb). ras inhibition also suppresses retinal leukocyte stasis, cd4 + t - cell activation [17, 18, 88 ]. lastly, when the expression levels of ras pathway components are examined in eiu, prorenin, (pro)renin receptor, angiotensin ii, and at1r levels are elevated in the retina. these findings suggest that heightened inflammatory responses in the eye and ras activation are strongly correlated. besides being correlated with classically acute inflammation cases such as uveitis, one of the largest risk factors for developing prevalent and vision - threatening diseases such as dr, amd, and glaucoma is aging [13 ]. these age - related eye diseases [109, 110 ] and others [5, 6 ] are now known to be caused (at least partially) by chronic inflammation and oxidative stress. since ras inhibition may prolong the life spans of hypertensive [7173 ] or normotensive mammals, it is logical that age - related eye diseases may be prevented or treated by suppressing inflammation and oxidative stress. the main pathological event of dr and amd is abnormal neovascularization and vegf (vascular endothelial growth factor) has been known to be a large contributor for them [111113 ]. vegf is a potent angiogenic factor and an inflammatory cytokine that induces the accumulation, adhesion, and infiltration of leukocytes [114, 115 ]. inflammatory response in the retina can promote tissue ischemia by inducing vascular regression (vaso - obliteration) and also pathological angiogenesis. angiotensin ii can induce upregulation of vegf receptor (vegfr)-2 and angiopoietin-2 in retinal ecs [117, 118 ] and vegf in retinal pericytes (figure 3). oxygen - induced retinopathy (oir) is an animal model induced by continual aeration with 7580% oxygen in early postnatal stages. oir animals develop stereotypical phenotypes and is useful to evaluate vaso - obliteration and pathological angiogenesis (tuft formation) in the developing retina which is largely regulated by vegf. this phenotype can be prevented with ras inhibitors acei [122, 123 ], arb, or prrb [89, 124 ] that prevent pathological angiogenesis in oir. the use of arb and prrb has the added benefit of suppressing abnormal angiogenesis without suppressing physiological vascular regeneration [15, 124 ]. in animals exposed to oir ras inhibitors infiltration of vegf - expressing inflammatory cells into the vitreous cavity is thought to induce pathological angiogenesis by causing ecs to grow in the wrong direction. it is characterized by vascular loss due to hyperglycemia and inflammation due to oxidative stress and ages (advanced glycation end products) accumulation. in severe cases hypoxia induces abnormal neovascularization (proliferative diabetic retinopathy, pdr) in addition to hyperpermeability (diabetic macular edema ; dme). prorenin and angiotensin ii [125, 126 ] are found to be increased in the vitreous humor of pdr and dr patients. ras may potentiate the vascular phenotype of dr by upregulating vegf / vegfr-2 signaling (through angiotensin ii) [118, 119 ] thereby inducing neovascularization and promoting blood vessel permeability. in fact, vegf was initially named vascular permeability factor (vpf). although in one study acei administration seemed to attenuate retinal hyperpermeability in diabetic patients, interpretations of these studies are still being actively debated [129, 130 ]. however, recently three independent groups showed that arb prevents brb breakdown in animal models [131133 ]. in 1998 and 2008, the results of randomized double - blind placebo - controlled trials using acei or arb to treat dr were released from the euclid (eurodiab controlled trial of lisinopril in insulin - dependent diabetes ; acei treatment) and direct (diabetic retinopathy candesartan trial ; arb treatment) [24, 25 ]. afterwards, rass (renin - angiotensin system study) in which both inhibitors were tested in dr patients was also released. large number of participants were examined in these trials (354 (type 1 diabetes) for euclid, 1421 (type 1) and 1905 (type 2) for direct, and 285 (type 1) for rass, resp.), and the results from all three studies provided strong evidence that ras inhibition delays the onset or prevents the development of human dr symptom. for example, in direct, arbs were not effective with respect to primary endpoints and had differing effects regarding secondary endpoints in different patient groups (type i or type ii diabetes) [24, 25 ]. clues for why ras inhibition is effective for treating dr have come from animal studies. streptozotocin (stz) injections in rodents induce leukocyte stasis, blood vessel hyperpermeability, and formation of acellular capillaries. importantly, erg recordings are attenuated in rodents after stz injections before vascular phenotypes are observed, indicating that neuronal dysfunction precedes neovascularization in diabetic models [9, 135 ]. the administration of acei [137140 ], arb [10, 13, 14, 141 ], or prrb has been shown to rescue the vascular phenotypes of stz - induced diabetic retinas. to generate another and more severe model of dr, ren-2 transgenic rats (that have severe hypertension due to genetic knock - in of a mouse ren-2 renin gene) can be injected with stz. in these rats advanced vascular phenotypes are observed (including abnormal endothelial proliferation). even in this model acei or arb ras inhibitors probably function by suppressing inflammatory cascades [10, 14 ] and by preventing oxidative stress by limiting nfb and nad(p)h activation. ras inhibitors may also function to directly inhibit glucose accumulation into retinal cells by modulating glut-1 (glucose transporter 1) expression. furthermore, arb was reported to influence the expression of glyoxalase i, a key regulator of ages. lastly, even though at1r and at2r are considered to have opposing functions at2r inhibition may also effectively treat dr by suppressing vegf and angiopoietin-2 expression levels in experimental retinopathies [33, 149 ]. the greatest risk factors are aging and smoking, and the central phenotypes are choroidal neovascularization (cnv ; wet amd) and atrophy of photoreceptors and rpe cells (dry amd). while no cure exists for dry amd, wet amd is currently treated with vegf inhibitors [112, 113 ]. inflammation exacerbates the wet amd phenotype since infiltrating macrophages promote cnv formation [150152 ]. the size of the laser - induced lesions after treatment with acei, arb, and prrb is significantly reduced. ras inhibition may protect against cnv formation by inhibiting ras activity and suppressing erk signaling (directly with (pro)renin receptor - mediated intracellular signaling). rpe cells are positioned between the choroidal vasculature and photoreceptors and have function to maintain the visual (retinoid) cycle and to form a tight seal that prevents choroidal vessel invasion. angiotensin ii signaling in rpe cells increases abnormal production [155157 ] and excessive turnover of ecm via mmp (matrix metalloproteinase)-2 and -14 thereby weakening the seal that prevent choroidal ec invasion. these studies suggest that ras inhibition may be an effective treatment for amd as well as dr. the feature of this disease is neurodegenerative of rgcs, but it can be caused by heterogeneous and complex mechanisms. one direct mechanism to induce rgc death is to increase the intraocular pressure (iop). studies devoted to developing new methods of controlling iop are critical and ongoing. however, a subpopulation of glaucoma patients have normal iop (normal tension glaucoma, ntg). this complicates the development of effective therapies since both forms are induced by seemingly separate mechanisms. some ras components including angiotensin ii receptors are expressed in cb cells [90, 159, 160 ] that secrete aqueous humor and regulate iop. like other antihypertensive drugs such as calcium channel blockers, acei or arb decreases iop in humans and other primates [161165 ] although iop is considered to be regulated independently of systemic blood pressure. in an experimental model of high iop and glaucoma, arb treatments effectively suppress rgc death. these findings suggest that ras inhibition may be effective for treating glaucoma patients with high iop. angiotensin ii receptors are expressed inside and outside of the bbb [75, 76, 7981 ] and the brb [8, 92, 99, 100 ] indicating that both circulating and tissue ras exist in the cns, and if dysregulated, could elicit pathological effects. indeed, ras inhibition can attenuate the degree of inflammation in the brain and the eye [166, 167 ]. inhibiting ras can prevent experimental brain injuries induced by middle cerebral artery occlusion [168, 169 ] by suppressing vascular inflammation, including bbb breakdown, and/or regulating neural apoptosis directly. interestingly, at2r is more highly expressed in developing neuronal tissues in vivo than in adult tissues and at2r stimulation promotes axonal regeneration of optic nerve and minimizes formation of ischemia - induced cerebral lesions. this suggests that arb, which not only blocks at1r but also causes angiotensin ii to bind at2r, may be an ideal drug for treating inflammatory diseases in the cns. inhibition of ras may also prevent stress - induced behaviors including anxiety, depression, and panic by suppressing the release of corticotrophin - releasing factor [176178 ]. furthermore, recent studies suggest that brain ras may potentiate alzheimer 's disease progression by stimulating the production of beta amyloid [179182 ]. retinal dysfunction as detected in erg recordings can be observed in early diabetic animal models and in humans before vascular changes and neural cell loss are observed. amazingly, these deficits can be prevented by inhibiting ras [9, 183, 184 ]. we have reported that arb prevents retinal dysfunction (e.g., decrease of amplitude and an extension of the implicit time of erg) in eiu and in stz - induced early diabetic retinas. furthermore, in these inflamed retinas, we determined that angiotensin ii prompted the degradation of the presynaptic protein synaptophysin through the ubiquitin proteasome system (ups) [8, 9 ]. ups - mediated degradation of rhodopsin (part of the light - responsive complex in photoreceptors) can also be observed in eiu via stat3 activation (which operates downstream of at1r) [8, 185 ]. additionally, stat3 signaling serves as a negative regulator of rhodopsin in differentiating photoreceptors during retinal development [186, 187 ]. thus, regulating angiotensin - ii - induced protein degradation could serve as an important neuroprotective measure (figure 3). another target of inflammation is reactive glia including microglia, astrocytes, and muller glia. microglia are resident cns myeloid - derived cells and mediate critical immune and inflammatory responses. at1r signaling induces activation of microglia via nfb and ap-1 [189, 190 ]. gfap (glial fibrillary acidic protein) is a differential and reactive marker of astrocyte and muller glia, respectively, and its transcription is regulated by stat3 activation. the activation of astrocytes and muller glia in experimental retinopathy can be prevented by arb [8, 192 ] (figure 3), although it is important to consider that the contributions of reactive glia can be context dependent. iop - independent rgc apoptosis can be observed in stz - induced diabetes, after ischemia / reperfusion, after optic nerve crush, and after intraocular nmda (n - methyl - d - aspartic acid) injections in animal models. rgc loss in diabetic hypertensive models can be prevented by arb which restores oxidative redox and mitochondrial functions. acei or arb also prevents rgc apoptosis in ischemia / reperfusion models by suppressing toxic oxidative stress. polymorphisms of ras pathway genes are reported to be associated with brain infarction or its early lesion [197199 ] and at2r gene polymorphisms are reported to be associated with the risk of ntg. these findings may indicate that ras inhibitors may directly protect retinal neurons from apoptosis and further suggest that ras inhibition may be useful for therapeutic treatments of iop - independent glaucoma. ras, which has been classically known as blood pressure regulator, is becoming widely recognized as a proinflammatory mediator. many age - related ocular diseases may be caused or exacerbated by chronic inflammation. cells in the eye are responsive to circulating and tissue ras and increasing evidence indicates that ras inhibition may prevent various ocular diseases including uveitis, amd, and glaucoma. based on the findings from multiple clinical trials, ras inhibitors are effective therapeutic agents for treating dr although the results of these studies must be examined critically since the inhibitors were not universally beneficial. other groups including our own have shown that ras inhibitors protect neurons from oxidative stress and apoptosis by preventing posttranslational ubiquitination of proteins critical for retinal functions. although not mentioned previously in this paper, another new and exciting ras inhibitor, aliskiren (a direct renin inhibitor), has been developed. therefore, work is underway to characterize existing ras inhibitors and to develop novel inhibitors since they hold great promise for attenuating chronic inflammation and for treating multiple ocular and nonocular diseases. | the renin - angiotensin system (ras) is a hormone system that has been classically known as a blood pressure regulator but is becoming well recognized as a proinflammatory mediator. in many diverse tissues, ras pathway elements are also produced intrinsically, making it possible for tissues to respond more dynamically to systemic or local cues. while ras is important for controlling normal inflammatory responses, hyperactivation of the pathway can cause neural dysfunction by inducing accelerated degradation of some neuronal proteins such as synaptophysin and by activating pathological glial responses. chronic inflammation and oxidative stress are risk factors for high incidence vision - threatening diseases such as diabetic retinopathy (dr), age - related macular degeneration (amd), and glaucoma. in fact, increasing evidence suggests that ras inhibition may actually prevent progression of various ocular diseases including uveitis, dr, amd, and glaucoma. therefore, ras inhibition may be a promising therapeutic approach to fine - tune inflammatory responses and to prevent or treat certain ocular and neurodegenerative diseases. |
individuals included in the analysis participated in the dpt-1 oral insulin trial (5). all oral insulin trial participants were relatives of t1d patients who were positive for islet cell autoantibodies and insulin autoantibodies. the participants initially had normal oral glucose tolerance (fasting glucose value 1.66 years from diagnosis (11.2 13.6 u / ml, not significant). this difference was also evident in the multivariate analysis (1.66 years from diagnosis : 35.4 12.7 u / ml [p = 0.011 ]). to further examine the consistency of the findings between analysis 1 and analysis 2, we used the regression coefficients from the 48 progressors excluded from analysis 1 to develop a curve to describe the change in fpir with the approaching diagnosis. this curve is shown in fig. 2 along with the curve of those followed longitudinally in analysis 1. (baseline characteristics of the two groups are shown in supplementary tables 2 and 3. starting from the same value (116.4 u / ml) as the mean of the fpir 2.5 years before diagnosis of those followed longitudinally, the pattern of decline was almost the same : a gradual decline from 2.5 to 1.5 years before diagnosis followed by a steep decline from 1.5 to 0.5 years before diagnosis. thus, using separate samples and different analyses, the pattern of decline predicted by the regression procedure (analysis 2) was consistent with the actual decline (analysis 1). curves of fpir values during the progression to t1d from the actual serial values of the progressors in analysis 1 and the values derived from the regression model for the other progressors from analysis 2. the curve for analysis 1 is plotted according to the mean times from diagnosis of the fpir measurements within each yearlong interval. for the purpose of comparison, the curve from analysis 2 was assigned the same starting value of 2.5 years and plotted according to the same time points. the patterns are similar, with a gradual decline from 2.5 to 1.5 years and a marked decline from 1.5 to 0.5 years before diagnosis. twenty - six of the 74 progressors analyzed had fpir measurements at baseline (mean sd 4.4 3.4 years before diagnosis), 1.66 years from diagnosis (11.2 13.6 u / ml, not significant). this difference was also evident in the multivariate analysis (1.66 years from diagnosis : 35.4 12.7 u / ml [p = 0.011 ]). to further examine the consistency of the findings between analysis 1 and analysis 2, we used the regression coefficients from the 48 progressors excluded from analysis 1 to develop a curve to describe the change in fpir with the approaching diagnosis. this curve is shown in fig. 2 along with the curve of those followed longitudinally in analysis 1. (baseline characteristics of the two groups are shown in supplementary tables 2 and 3. starting from the same value (116.4 u / ml) as the mean of the fpir 2.5 years before diagnosis of those followed longitudinally, the pattern of decline was almost the same : a gradual decline from 2.5 to 1.5 years before diagnosis followed by a steep decline from 1.5 to 0.5 years before diagnosis. thus, using separate samples and different analyses, the pattern of decline predicted by the regression procedure (analysis 2) was consistent with the actual decline (analysis 1). curves of fpir values during the progression to t1d from the actual serial values of the progressors in analysis 1 and the values derived from the regression model for the other progressors from analysis 2. the curve for analysis 1 is plotted according to the mean times from diagnosis of the fpir measurements within each yearlong interval. for the purpose of comparison, the curve from analysis 2 was assigned the same starting value of 2.5 years and plotted according to the same time points. the patterns are similar, with a gradual decline from 2.5 to 1.5 years and a marked decline from 1.5 to 0.5 years before diagnosis. the findings show that the decline in the fpir during the progression to t1d accelerates as the diagnosis approaches. this was evident in the two separate samples of the progressors studied. in the longitudinal analysis of serial fpirs (analysis 1), there was a gradual loss that was followed by a more substantial loss. in the regression analysis (analysis 2), there was an association between the rate of loss of the fpir and the proximity to diagnosis of t1d both for all the progressors and with the exclusion of those in analysis 1. the high degree of consistency of the findings, derived from different samples of progressors and different analyses, provides additional supporting evidence for the acceleration of the decline in the fpir. although the curves appear to show an abrupt increase in the acceleration of decline, this is not necessarily the case ; the acceleration could occur in a more gradual manner. still, the data show that the decline in the fpir becomes more rapid as the diagnosis of t1d approaches. the acceleration appears to become especially marked between 1.5 and 0.5 years before diagnosis. of note, this time period appears to coincide with the time that the loss of -cell sensitivity to glucose becomes appreciable (9). the overall loss of the fpir from the baseline measurement to the last measurement was marked in the 26 progressors followed longitudinally, with a decline of 47.7% by 0.5 years before diagnosis. however, the extent of insulin loss before diagnosis is almost certainly greater for several reasons. it is likely that there already had been some loss of the fpir before the baseline measurement because the baseline fpir values were lower in the progressors than in the nonprogressors with adjustments for age and bmi. in addition, the shape of the curves in fig. 2 and data from an analysis of serial ogtts (10) suggest that the rate of decline could be even greater during the last 6 months before diagnosis. finally, dpt-1 participants were mostly diagnosed through ogtt surveillance rather than through clinical presentation (11). the interpretation of fpir trends in the nonprogressors is complicated by the likelihood that a number of them would have been diagnosed with further follow - up. to our knowledge, no prior studies have described the pattern of decline of the fpir during the progression to t1d. the oral insulin trial was unique in that such a large number of autoantibody positive individuals were followed with serial ivgtts at yearly intervals. we have previously shown that the 30- to 0-min c - peptide difference from ogtts (which correlates with the fpir) also declines appreciably during progression (12). it is possible that the findings pertaining to the loss of the fpir are not fully representative. additionally, the criteria for inclusion in the longitudinal analyses could have excluded faster progressors. however, data from prior studies suggest that t1d characteristics are similar between t1d patients who have relatives with t1d and t1d patients who have no relatives with the disease (sporadic cases) (1315). moreover, 76% of the progressors in the oral insulin trial were included in the analyses. although several explanatory hypotheses can be formulated, it would be important to discern whether the accelerated decline of the fpir is the result of the primary pathogenetic process or whether it relates more to secondary factors, such as the possible impact of increasing glucose levels on -cells during progression. it is possible that an impaired -cell could be particularly susceptible to small changes in glucose concentration ; however, there are no data available to support this. in conclusion, the findings show that the loss of -cell function accelerates well before the diagnosis of t1d. thus, as treatments that preserve insulin secretion become available, it will be essential to identify individuals as early as possible during progression. with this in mind, there is a need to refine our ability to identify very - high - risk individuals years before diagnosis and to test potential interventions at that time. | we studied the change in the first - phase insulin response (fpir) during the progression to type 1 diabetes (t1d). seventy - four oral insulin trial progressors to t1d from the diabetes prevention trial type 1 with at least one fpir measurement after baseline and before diagnosis were studied. the fpir was examined longitudinally in 26 progressors who had fpir measurements during each of the 3 years before diagnosis. the association between the change from the baseline fpir to the last fpir and time to diagnosis was studied in the remainder (n = 48). the 74 progressors had lower baseline fpir values than nonprogressors (n = 270), with adjustments made for age and bmi. in the longitudinal analysis of the 26 progressors, there was a greater decline in the fpir from 1.5 to 0.5 years before diagnosis than from 2.5 to 1.5 years before diagnosis. this accelerated decline was also evident in a regression analysis of the 48 remaining progressors in whom the rate of decline became more marked with the approaching diagnosis. the patterns of decline were similar between the longitudinal and regression analyses. there is an acceleration of decline in the fpir during the progression to t1d, which becomes especially marked between 1.5 and 0.5 years before diagnosis. |
about 130170 million people worldwide have been infected by hepatitis c virus (hcv). hepatocytes represent the major site of viral replication, and the replication of hcv is present in extrahepatic tissues and peripheral blood mononuclear cells. previous studies have shown that 3876% of patients with chronic hcv infection develop at least one extrahepatic manifestation (ehm) [3, 4 ]. an association between hcv and mixed cryoglobulinemia (mc) was first described ; subsequently, the involvement of many organs and systems was reported (kidney, skin, eyes, joints, and nervous system). the infected extrahepatic tissues might act as a reservoir for hcv and play a role in both hcv persistence and reactivation of infection. hcv, as an etiological agent replicating and expressing viral proteins in extrahepatic tissues itself, contributes to ehm associated with chronic hcv infection. an important feature of hcv is that the virus avoids immune elimination ; a consequence is chronic infection and an accumulation of circulating immunocomplexes and autoimmune phenomena [68 ], as recently cheng. these ehm mainly include autoimmune disorders [1012 ] such as mc [13, 14 ] and sjogren 's syndrome and endocrinological diseases as autoimmune thyroid disorders (aitd) and type 2 diabetes [1517 ]. hashimoto 's thyroiditis or autoimmune chronic thyroiditis (at) is among the most common thyroid diseases. at is the most widespread thyroiditis form and its prevalence is definitely more frequent in female gender and in the elderly. the incidence in female gender is of 3,5 cases/1000 subjects per year, while in men it is lower (0,8 cases/1000 persons per year) : there is a remarkable variability in different geographic areas. at is an organ - specific autoimmune disease, morphologically characterized by a chronic lymphocytes infiltration of thyroid and the presence of circulating autoantibodies such as antiperoxidase (abtpo) and antithyroglobulin (abtg). the inflammatory process leads to a follicular destruction ; indeed, at is the most common cause of hypothyroidism in areas of iodine sufficiency. occasionally, thyroid stimulating hormone (tsh) receptor blocking antibodies can be responsible of an atrophic form of at ; more rarely, anti - tsh receptor stimulating antibodies can cause a transient form of hyperthyroidism (hashitoxicosis). risk factors associated with at are numerous [2124].age : the prevalence of disease tends to increase with age.genetic : a significant association between hashimoto 's thyroiditis and some histocompatibility antigens (hla - dr, hla - dr5, and some dq alleles) is demonstrated. many other susceptibility genes have been associated with at ; for example, specific ctla4 gene polymorphisms are linked to a possible development of antithyroid antibodies.iodine : an increased at prevalence is observed in areas of iodine sufficiency, compared with iodine - deficient areas [26, 27].selenium : a selenium deficit is linked to a higher at prevalence.irradiation : at occurs more frequently after the exposure to low doses of radiations.cytokine : the treatment with interferon- (ifn-), or with interleukin- (il-) 2, can promote the onset of at in predisposed patients.infections : it was seen that several viral infections can predispose to an at in animals. moreover, different studies tried to associate at with viral infections in humans with conflicting results [3033 ]. genetic : a significant association between hashimoto 's thyroiditis and some histocompatibility antigens (hla - dr, hla - dr5, and some dq alleles) is demonstrated. many other susceptibility genes have been associated with at ; for example, specific ctla4 gene polymorphisms are linked to a possible development of antithyroid antibodies. iodine : an increased at prevalence is observed in areas of iodine sufficiency, compared with iodine - deficient areas [26, 27 ]. cytokine : the treatment with interferon- (ifn-), or with interleukin- (il-) 2, can promote the onset of at in predisposed patients. infections : it was seen that several viral infections can predispose to an at in animals. moreover, different studies tried to associate at with viral infections in humans with conflicting results [3033 ]. in a first study, tran. report two cases of hashimoto 's thyroiditis associated with chronic active hcv infection, suggesting that hcv infection might be involved in the appearance of at [34, 35 ]. the prevalence of hcv infection in patients with different thyroid disorders has been evaluated by several studies with conflicting results. evaluated the prevalence of hcv infection in 200 patients with thyroid diseases ; among 50 patients with simple goiter, none were anti - hcv - positive ; among 50 individuals with goiter, 2 were positive ; among 5 individuals with myxedema, 2 were positive ; among 50 patients with hashimoto 's thyroiditis, 12 were positive. recently, yang. compared 462 persons with positive abtpo and/or abtg to 360 persons with antibody negativity and no difference in the prevalence of anti - hcv positivity between the 2 groups (1.3% versus 0.53% ; p > 0.05) was found. in a study conducted by marconcini., 66 hcv+ patients were evaluated and abtpos were detected in 4/54 (7.4%) of the patients, whereas abtgs were detected in none of the patients (0/48). conflicting results have been reported from earlier studies of patients with chc, with some supporting an association of hcv infection with aitd [3947 ] and others not [48, 49 ]. however, some of the earlier studies were negative because of the lack of control for factors which may affect the development of thyroid autoimmunity, such as iodine intake. indeed, the largest study about hcv and thyroiditis, in which iodine deficiency was evaluated, demonstrated that both hypothyroidism and thyroid autoimmunity were significantly more common in patients with hcv compared to controls. the prevalence of thyroid disorders in 630 consecutive patients with chronic hepatitis due to hcv infection was investigated ; all patients were free of cirrhosis and hepatocarcinoma and were not on interferon treatment. three control groups were included : (a) 389 subjects from an iodine - deficient area, (b) 268 persons living in an area of iodine sufficiency, and (c) 86 patients > 40 years of age with chronic hepatitis b. levels of thyroid - stimulating hormone (tsh), free t4 (ft4), and free t3 (ft3), as well as abtgs and abtpos, were measured. mean tsh levels were higher (p = 0.001) and ft3 and ft4 levels were lower (p mean sd control 1 ; > 167 pg / ml) was present in 7% of control 1, 21% of control 2, 49% of mc, and 78% of mc + at (p mean sd control 1 ; > 730 pg / ml) was present in 2% of control 1, 1% of control 2, 18% mc, and 21% of mc + at (p < 0.0001). among the proinflammatory cytokines, il-1 and tnf- were not associated with the presence of at in mc + hcv patients, while il-6 was modestly but significantly increased in patients with at [5, 123125 ]. on the whole, in agreement with what was observed in other autoimmune disorders [126129 ], the above reported data underline the importance of the activation of the th1 immunity in the initiation of at in patients with mc + hcv. in conclusion, the abovementioned results show a high prevalence of aitd in patients with chc infection. the presence of a higher risk of at in female gender, increased circulating levels of abtpos, and increased risk of hypothyroidism in female gender and abtpo - positive subjects characterized the pattern of thyroid disorders observed in hcv infection. in hcv patients with thyroid cancer, thyroidectomy is required and, if appropriate, radioiodine treatment. patients with hcv infection with aitd where nodules occurred and in fine needle aspiration biopsy without neoplastic processes do require careful observation. | frequently, patients with hepatitis c virus (hcv) chronic infection have high levels of serum anti - thyroperoxidase and/or anti - thyroglobulin autoantibodies, ultrasonographic signs of chronic autoimmune thyroiditis, and subclinical hypothyroidism, in female gender versus healthy controls, or hepatitis b virus infected patients. in patients with hcv - associated mixed cryoglobulinemia (mc + hcv), a higher prevalence of thyroid autoimmune disorders was shown not only compared to controls, but also versus hcv patients without cryoglobulinemia. patients with mc + hcv or hcv chronic infection show a higher prevalence of papillary thyroid cancer than controls, in particular in patients with autoimmune thyroiditis. patients with hcv chronic infection, or with mc + hcv, in presence of autoimmune thyroiditis, show higher serum levels of t - helper (th)1 (c - x - c motif) ligand 10 (cxcl10) chemokine, but normal levels of th2 (c - c motif) ligand 2 chemokine, than patients without thyroiditis. hcv thyroid infection could act by upregulating cxcl10 gene expression and secretion in thyrocytes recruiting th1 lymphocytes that secrete interferon- and tumor necrosis factor-. these cytokines might induce a further cxcl10 secretion by thyrocytes, thus perpetuating the immune cascade, which may lead to the appearance of autoimmune thyroid disorders in genetically predisposed subjects. a careful monitoring of thyroid function, particularly where nodules occur, is recommended in hcv patients. |
recurrent spontaneous abortion (rsa) is defined as a sequence of three or more consecutive spontaneous abortion. rsa is a heterogeneous condition which may have many possible causes ; more than one contributory factor can lead to recurrent pregnancy losses. the major causes of rsa are genetic, endocrinological, immunological, anatomical factors and yet can be unexplained with all these in some cases. in unexplained rsa, immunotherapy (allogenic leukocyte immunization from the partner) has been used to treat the couples. antibody to human leucocyte antigen (hla) was first identified in the serum of a polytransfused patient ; subsequently materno - fetal alloimmunization was also shown to produce anti - hla antibodies in pregnant women. since then, pregnant women have been the most common source of these hla antisera for routine hla serological typing (though monoclonal antibodies have also been raised recently). the aim of this study is to identify the role of anti - hla antibodies in rsa patients. a total of 80 randomly selected couples with unexplained three or more recurrent spontaneous abortion and control group of 50 pregnant women (age group 20 to 40 years) who had no previous abortions but had previous 1 or 2 pregnancies recruited in the 20 - 22 week of pregnancy. all the women with rsa were found to be negative for cytogenetic and autoimmune abnormalities such as anti - phospholipid antibodies (apas), antithyroid antibodies (atas), anti - nuclear antibodies (anas), antineutrophil cytoplasmic antibodies (ancas) and lupus antibodies (la). the sera of women were investigated for the anti - hla antibodies against their husband 's lymphocyte. the anti - hla antibodies were analyzed following the standard two stage nih microlymphocytotoxicity assay. these rsa patients on follow - up showed that they aborted the foetus while the normal females delivered a normal alive when they were followed up during their pregnancy. the anti - hla antibodies were tested in 80 rsa and 50 control couples [table 1 ]. in rsa case, 21 sera (26.25%) versus 4 sera (8.0%) were found positive for hla antibodies against husband 's lymphocytes. most of the sera showed hla - a and hla - b antibodies which had high titer. for screening, sixty well tissue typing tray consisted of one positive, one negative control, 21 positive sera of rsa women and 4 antenatal control sera. the antisera were serially diluted up to 1 : 4096 and tested for anti - hla antibodies. the results indicated that 9 out of 21 (42.85%) (or=2.25 ; etiological fraction=0.23) positive sera showed reaction at dilution 1 : 4096 and 5 sera (23.80%) showed reaction at dilution 1 : 2048. one each of positive sera showed no reaction at all the dilutions including neat samples used and positivity at neat sample, respectively. few of the sera showed reaction at highest dilution only, but the same was not observed in the corresponding neat sample which indicates presence of very low amount of antibodies against hla antigen. it is also observed that maximum positivity was for 1 : 8 dilution of all the sera used. in the case of normal controls, it was observed that only 1 out of 4 sera showed presence of antibodies at highest dilution while rest 3 sera tested showed variable results. initially many studies have been done to determine whether or not there is a connection between rsa and couples who share hla alleles. excess sharing of hla antigens between spouses has been considered by some to be mechanism leading to maternal hyporesponsiveness to paternal antigens encountered in pregnancy and therefore subsequent miscarriage. this hyporesponsiveness was considered to be shown by a lower incidence of anti - paternal antibody in rsa. wide variation in the incidence of anti - hla antibodies has been reported in the sera of normal pregnant women. values range from 7.3% to 36% (7.3%, swedish women ; 18.7%, caucasian women ; 21.6%, american women ; 29%, mestizo women and 9.6%, warao women ; venezulean women ; 36% usa women and south indian women 10.6%. another study detected anti - hla antibodies in only 5% of women with successful pregnancies during the first trimester, compared with an antibody prevalence of 10% in women who miscarried. in a prospective immunization study, christiansen. found higher frequencies of anti - hla antibodies in women with rm who miscarried (29%) compared with 18% of women who successfully delivered. due to variation in immunization and the resultant outcome, a wide variation in the incidence of anti - hla antibodies in the sera of normal pregnant women have been reported in literature. it has been reported earlier that 27.8% of rsa women had anti - hla antibodies from northern india. in our study we have found an incidence of 26.25% anti - hla antibodies, which suggests that the blocking factors as well as immunity towards the husband 's lymphocytes could be different among western indian rsa couples. | background : recurrent spontaneous pregnancy (rsa) is defined as a sequence of three or more consecutive spontaneous abortions. one of the major causes of rsa is immunological where alloimmune antibodies develop towards human leucocyte antigen (hla) antigens. earlier research had suggested that anti - hla antibodies are produced in normal women ; studies have been reported that normal pregnant women develop anti - hla antibodies, mostly after 2028 weeks of gestation.aim:to evaluate the role of anti - hla antibodies in rsa patientsmaterials and methods : a total of 80 randomly selected couples with unexplained three or more rsa and control group of 50 normal pregnant women were screened for anti - hla a and b antibodies. the anti - hla antibodies were analyzed following the standard two - stage nih microlymphocytotoxicity assay.results:in our study group a high frequency of anti - hla antibodies among women with rsa (26.25%) was detected compared to normal pregnant women (8.0%). most of the sera showed hla - a and hla - b antibodies which had high titer, up to a dilution of 1 : 4096.conclusion:this incidence of high anti - hla antibodies in rsa women during early weeks of gestation may explain the recurrent pregnancy loss. |
protostars accrete mass through discs, and as material moves inwards through the disc, angular momentum builds up. without a mechanism to release this buildup of angular momentum, there are a number of mechanisms for dispersing angular momentum, including the launching of winds, outflows and jets. they allow the remaining material to continue moving through the disc, eventually getting to the inner edge, and becoming available for accretion by the star. all three of these large - scale phenomena are intrinsically linked with each other (see for example, panoglou. jets are generally observed in high energy, ionized (optical) tracers and in radio continuum emission. highly collimated, high - velocity jets are thought to entrain surrounding material forming molecular outflows, while winds are thought to be lifted directly from the disc, with the suggestion that the jets may be collimated by the wider angle magnetohydrodynamic disc winds (e.g. frank. these phenomena exhibit different properties from each other (e.g. in terms of collimation, gas velocities), however the terms wind and outflow are often used interchangeably since their observed properties are inherently similar (e.g. they can be detected in the same tracers). winds, being launched from the disc, come in two forms ; photo - evaporative flows and molecular disc winds. the former is caused by the forming star photoionizing the disc surface (e.g. alexander, clarke & pringle 2006), at which point highly energetic particles whose velocity exceeds the escape velocity will leave the system. these flows have velocities of > 10 km s and are seen in ionized atomic species. the later, molecular disc winds, are launched from magnetic foot points within the disc, and are collimated by the magnetic field (e.g. pudritz & ouyed 1997). they are a key mechanism for releasing angular momentum, and have been seen in molecular co (e.g. klaassen. molecular disc winds can self - shield such that the wind gas remains cool and thus molecular (e.g. panoglou. outflows, generally traced with molecular line emission in the (sub-)mm, highlight the interaction between a jet / wind and its environment : as the jet or wind pushes through the ambient material, it entrains a portion of that material (through processes such as turbulence and viscosity), accelerating it to higher velocities. because outflows trace entrained material, their flow speeds tend to be lower, and their opening angles tend to be larger than those of jets or winds. outflowing material to describe the generalized molecular gas moving away from the disc, regardless of whether it is in a wind or an outflow. hl tau is an interesting region for testing the interconnectedness of these phenomena as both atomic jets (e.g. detected in h, krist. 2008) and molecular outflows (e.g. lumbreras & zapata 2014) have previously been observed. hl tau, at a distance of 140 pc (kwon, looney & mundy 2011), is a young protostar of between 0.55 and 1.3 m (stephens. 2014 ; atacama large millimeter / submillimeter array (alma) partnership. 2015). using near - ir polarimetry measurements, lucas. (2004) found a strongly twisted magnetic field surrounding the disc in hl tau. they were unable to measure the field of the disc itself due to the high levels of extinction. (2014) measured the magnetic field in the disc and found it to be dominated by a toroidal magnetic field component. they found that its structure is not consistent with either completely toroidal or completely vertical structures ; the field morphology must come from a combination of these structures. the collimated h jet emission appears to be concentrated in the blueshifted lobe, which hosts a poorly collimated blueshifted molecular outflow. the [s ii ] emission from the jet is seen in both the red and blue lobes (mundt. (2007) showed that the 1.64 m continuum emission of hl tau exhibits a cross pattern with symmetric red and blue components on 1 arcsec scales, suggesting that the outflow is symmetric across the disc axis. they also detect a collimated jet in [fe ii ] distinct from this outflow. beck, bary & mcgregor (2010) show that the br emission from hl tau is coincident with the blueshifted jet emission, however it is not as blueshifted as the other jet tracers detected in this source to within their velocity resolution. the blue jet coming from hl tau (hh 151) was first detected in the early 1980s (mundt & fried 1983), and curiously : (1) only becomes bright in h 20 arcsec from the powering source, and (2) appears at an angle to its expected direction ; its observable base is along the disc axis, however from there it proceeds away from the disc at an angle. these two properties of the jet are generally ascribed to interaction with the wind from xz tau (e.g. movsessian, magakian & moiseev 2012), because these two forming stars are indeed spatially co - located (not just projected to be close on the sky). the base of the elongated h emission is coincident with the [s ii ] jet emission (mundt. 1990), and the kink in the h emission can be seen in their fig. the high - velocity sub - mm emission in this region was most recently presented by lumbreras & zapata (2014) at a resolution of 2 arcsec, showing collimated redshifted and blueshifted outflowing material in co. however, these two lobes are not aligned in a classical bi - polar fashion, with the blueshifted lobe offset from the line connecting the blueshifted (optical) jet, and redshifted emission. bubble of blueshifted emission and likely interacting with xz tau, which is located within, and powering, the bubble. it should be noted that xz tau is thought to be a triple system (carrasco - gonzlez. 2009) with two of the components being m3 and m2 classical t - tauri stars (krist. 2008). in this paper, we present an analysis of the alma science verification data of co (j=10) taken as part of the long baseline campaign in 2014. in section 2, we present a brief overview of the observations, in section 3 we present the images of the largest scale co emission recovered in these observations, highlighting the wind and outflow components. in section 4, we analyse these results, de - project the wind velocities and constrain the wind launch radius. in section 5, we summarize our findings. the observations presented here come from the alma archive, and were taken as part of the alma science verification, long baseline campaign (project 2011.0.00015.sv). the integration times, calibrators (and their purposes), observing date and minimum and maximum baseline lengths used in each of the executions contained in this set of observations are listed in table 1, in which each execution is identified by the last four characters of the filename given in the alma archive. details about the data, and reduction can be found in alma partnership. we used unmodified versions of the released reference images of the band 3 continuum and co emission. the released spectral line data were tapered to highlight the larger scale structures, which results in a larger synthesized beam. the beam sizes and rms noise limits for the data sets are given in table 2. rms noise levels have units of mjy beam per 1 km s channel for the co line emission, and mjy beam for the continuum. these observations were not designed to recover the large - scale outflowing gas, thus much of the emission has been filtered out. the shortest baselines were 15.5 m, which means the largest angular scale to which these observations could be sensitive is approximately 41 arcsec. this corresponds to approximately 77 per cent of the band 3 primary beam (53 arcsec). comparing our co observations to those of welch. (2000) from berkeley - illinois - maryland association (bima) telescope at a resolution of 7 arcsec shows that much of the co emission in the blueshifted emission is likely filtered out of our observations ; their structures are much larger (2.5 arcmin) than those seen with these alma observations. in terms of the redshifted emission lobe, the size and shape of their recovered structures (see their fig. 2) are consistent with those seen with alma. because their observations are in co (j=10), there are too many uncertainties (including an isotope ratio) to quantify the amount of missing flux in our co (j=10) observations. in addition to the alma science verification data, we make use of archival hubble space telescope (hst) advanced camera for surveys (acs) data for this region, showing the h and [n ii ] image first presented in krist. here, we present the outflowing molecular gas properties, highlighting the morphological properties of the red (section 3.1) and blue (section 3.2) emission and the opening angle of the red component of the flow (section 3.3). we further calculate the flow kinematics inferred from the emission and its velocity structure, making use of the known inclination angle on the sky (section 3.4). for our analysis, we have made extensive use of integrated intensity (zeroth moment), and intensity weighted velocity (first moment) maps of the co emission. these maps were clipped at 3 and 5, respectively, using the noise level quoted in table 2 and were integrated over the velocity ranges of 05.5 km s and 720 km s, respectively, for the blueshifted and redshifted emission. we note that the spatial extent of the redshifted emission detected in these observations is consistent with that of lumbreras & zapata (2014) observed with the submillimeter array (sma). to clarify, what lumbreras & zapata (2014) call a wide - angle outflow, we discuss as an outflow entrained by a wide - angle wind (which we shorten to flow), to be more consistent with the terminology in arce. (2007). fig. 1 shows the first moment map of the co emission, highlighting the positions of the redshifted and blueshifted emission lobes. the colourscale shows the velocities of the outflowing material in co. this map already shows the complex morphology of the co emission. it highlights the sharp transition between red and blue emission, and that redshifted emission is present towards the outer edge of the blueshifted emission (away from the disc). as highlighted by green lines, these two red features make an angle with the disc quite similar to the opening angle of the red flow, as discussed further below. first moment map of the co emission from hl tau (cut at 10, integrating over 020 km s). the black contours show the 5 to 25 levels of the continuum emission to highlight the position of the disc. note that the emission (co and continuum) at the left edge of the map is that from xz tau, as indicated. the green lines through the red lobe correspond to the white lines in fig. 2, which are then transposed on to the blue lobe. because the redshifted lobe appears to be limb brightened (the edges of the outflow appear to have the greatest intensities, see fig. 2), it is likely that the red emission is primarily coming from the conical edges of a flow, possibly with an excavated central cavity. hourglass morphology which could be suggestive of magnetic collimation (see for instance stephens the previous observations of lumbreras & zapata (2014) were of a too low resolution to see this limb brightening. redshifted co moment maps integrated over 720 km s. note that in the integrated intensity map (left - hand panel), the edges of the outflow appear to be limb brightened. these edges are what we use to calculate the opening angle of the flow, and how its collimation factor varies along the flow. close to hl tau, the opening angle is 90, however, further out, the flow appears to have an opening angle closer to 60. fig. the brightest blueshifted emission comes from quite near the disc, where the h emission is strongest as well. 4, towards the centre of the flow axis (which arises between the two peaks in the blueshifted material, and is labelled as jet), there is a small jet - like structure protruding from the h emission. blueshifted co moment maps integrated over 05.5 km s. note that both the integrated intensity and intensity weighted velocity increase significantly towards the centre (northern edge) of the blueshifted emission. blueshifted wind (blue contours, starting at 15 per cent of the peak intensity, increasing in levels of 10 per cent), overlaid on hst acs grey - scale image of a combination of h and [n ii ]. the blueshifted emission is not as collimated as the red, probably due to a combination of effects including the interaction with the xz tau bubble (which is expanding within the blueshifted co emission from hl tau, see for instance welch. the left - hand panel of fig. 2 shows the opening angle of the redshifted flow. its morphology can be decomposed into two components : one with a small - scale opening angle of 90, and a larger scale (collimated) opening angle of 60. this hourglass morphology could be due to magnetic collimation, like is the case for l1157-mm (stephens. (2014) are suggestive of field orientations which could collimate the flow. under the assumption that we are not observing a special orientation on the sky, we expect this limb brightened morphology to be representative of a conical morphology in 3d. additionally, we note that the 60 lines from fig. 2 are drawn in figs 1 (in green) and 7 (in white) to help guide the eye in these plots. note that in these two figures, the lines have been transposed on to the blue emission as well. from the line wing co emission, we quantified the mass, momentum and energy in the flow. the intensity in each velocity channel was summed, and/or multiplied by the velocity of that channel to determine the mass (m tdv), momentum (p mv) and energy (e m v/2). here, we assume the co is optically thin, and that there is likely missing flux from the largest scale structures in these data, therefore our column density and mass estimates are lower limits. using the extent of the red flow (20 arcsec), and the maximum velocity of the redshifted emission (5 km s), we estimate a kinematic age of approximately 2600 yr, with which we quantify the mechanical luminosity (l = e / t), and mass - loss rate (\documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } $ \dot{m}$\end{document } = m / t) of the flow. we note that this is an extreme lower limit to the age of the flow. the constants of proportionality in the first few equations are related to the abundance of co (taken to be 1 10), the ambient temperature (t = 50 k) and a multiplicative constant for co related to the energy of the j=10 transition, the partition function, and the degeneracy of the state (see appendix a2). we note that since the inclination angle of the flow is known (see section 4.1), the velocities used in the calculation have been corrected for inclination, and the results are given in table 3. changing our assumed temperature by 20 we note that our derived outflowing gas mass is approximately half that found in lumbreras & zapata (2014), while our momentum and kinetic energies are < 10 per cent of their values. the mass comparison gives an estimate of our missing flux, since we used the same local thermodynamic equilibrium (lte) [t = 50 k ] assumption. without knowing their velocity integration methods or limits derived flow kinematics (assuming a kinematic age of 2650 yr). note. the uncertainties on the mass and mass outflow rates are smaller than the precisions listed here. the method for calculating these uncertainties is presented in section a2, which takes into account the rms noise of the observations, but not things like co opacity or abundance and ambient temperature assumptions. as discussed in section 3.3, and shown in the left - hand panel of fig. 2, the flow has an opening angle of 90 at its base. we analyse this opening angle using the assumption of conical symmetry about the flow axis. this assumption is supported by the observation that the flow is limb brightened (left - hand panel of fig. 2). (2015) fit the uv plane visibilities of the dust continuum emission, and found an inclination angle of 46 0\documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } $ _ {.}^{\circ}$\end{document}2 for the disc in the plane of the sky. if the flow axis is perpendicular to the disc axis, then it should have an inclination angle of 44 with respect to the line of sight. this, coupled with the flow opening angle of 90 suggests part of each wind lobe should exhibit some counter - flow emission, i.e. emission within a certain lobe that, due to the large opening angle, has crossed the plane of the sky and therefore appears to be flowing in the opposite direction. as shown in the cartoon of fig. 5, there should be a small portion of the blue flow which has red velocities labelled as rs (redshifted) blue. similarly for the red flow, there is a small component labelled bs (blueshifted) red. these counter - flows, because they are close the plane of the sky, will have very small line - of - sight velocities. cartoon of the relationship between the flow, its 90 opening angle at the base, and the inclination angle of the disc (which is assumed to be perpendicular to the outflow). this representation explains why there is blueshifted emission coincident with the red flow, and redshifted emission coincident with the blue flow. rs blue and bs red counter flows are highlighted in the channel maps of fig. 6 in the 5.5 and 7.5 km s channels. in these two channels, the integrated emission of the blueshifted and redshifted winds is overplotted (respectively) with blue and red contours. this is to demonstrate where the blue and red wind lobes are, and highlight that there is additional emission in these channels spatially co - incident with the opposite wind lobe. the counter - flow emission components at 5.5 and 7.5 km s are also shown in fig. 8 shows the co spectra within the two black circles in fig. 7 to highlight that there is significant note that these circles were chosen a few arcsec from the disc to avoid contamination from the rotationally symmetric disc emission. channel map of the co emission from 4 to 10 km s. note that there is very little emission detected at the systemic velocity (6.5 km s), which may be due to filtering. the integrated intensities of the blueshifted and redshifted emission are shown as contours (from 10 per cent to 70 per cent of the peak intensity) in the two channels at 5.5 and 7.5 km s, where the counter - flow emission is strongest. the intensity contours are taken over the same velocity intervals as the moment 0 maps shown in figs 2 and 3 overlap in redshifted and blueshifted emission in the, respectively, the red contours consist of redshifted emission at 7.5 km s, while the blue contours show blueshifted emission at 5.5 km s. the labels show the predominant flow velocity within each cone ; opposite to the low - velocity contamination shown here. note that the bulk of the outflow material is not captured in these two channels, but exists at higher velocities from systemic (67 km s). the white lines correspond to the green ones in fig. 1, and cross at the position of the disc. the background grey - scale shows the integrated intensity of the co emission taken over the velocity range of the channel map in fig. 6. 8 come from regions of high contamination of red / blue emission within the two yellow circles shown here. spectra taken from two regions within the blueshifted (blue line) and redshifted (red line) portions of the wind, where contamination from gas at the opposite velocities is strongest. the black vertical line represents the lsr velocity (6.5 km s) suggested by alma partnership. rs blue and bs red emission in this flow, which confirms that the opening angle is large, and that the flow is indeed perpendicular to the disc, as expected. with the inclination angle known (with respect to the plane of the sky), the line - of - sight velocities of the red and blue emission known, and the opening angle of the cone assumed to be circularly symmetric (i.e. the opening angle measured in fig. 2 is consistent along the line of sight as well), we can estimate the true velocities of the red and blue flows solving (1)\documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } \begin{equation } \cos (1^\circ) \times v_{{\rm blue } } = v_{\rm b } -v_{{\rm lsr } } \end{equation}\end{document}(2)\documentclass[12pt]{minimal } \usepackage{amsmath } \usepackage{wasysym } \usepackage{amsfonts } \usepackage{amssymb } \usepackage{amsbsy } \usepackage{upgreek } \usepackage{mathrsfs } \setlength{\oddsidemargin}{-69pt } \begin{document } } { } \begin{equation } \sin (1^\circ) \times v_{{\rm blue } } = v_{\rm r } - v_{{\rm lsr } }, \end{equation}\end{document}where vblue is the average velocity of the blue flow, vlsr is the local standard of rest (lsr) velocity, vr and vb are the peak velocities redshifted and blueshifted emission of the two components shown in the spectrum. solving equation (1) for vlsr and putting that into equation (2), the only unknown becomes vblue, since vr and vb can be read from fig., we find redshifted and blueshifted wind velocities of 2.5 and 2.3 km s. we find, and quantify, evidence for an outflow entrained from a wide - angle wind from the hl tau system using high - resolution alma science verification observations of co (j=10). we find that the wind is indeed perpendicular to the disc, and that its inclination angle (44), combined with the wind opening angle (90) requires the wind to cross the plane of the sky. counter - flow emission at 5.5 and 7.5 km s. from these angles, we were able to quantify a characteristic wind velocity (2.4 km s) in both lobes. | outflowing motions, whether a wind launched from the disc, a jet launched from the protostar, or the entrained molecular outflow, appear to be a ubiquitous feature of star formation. these outwards motions have a number of root causes, and how they manifest is intricately linked to their environment as well as the process of star formation itself. using the atacama large millimeter / submillimeter array (alma) science verification data of hl tau, we investigate the high - velocity molecular gas being removed from the system as a result of the star formation process. we aim to place these motions in context with the optically detected jet, and the disc. with these high - resolution (1 arcsec) alma observations of co (j=10), we quantify the outwards motions of the molecular gas. we find evidence for a bipolar outwards flow, with an opening angle, as measured in the redshifted lobe, starting off at 90, and narrowing to 60 further from the disc, likely because of magnetic collimation. its outwards velocity, corrected for inclination angle is of the order of 2.4 km s1. |
inflammatory bowel disease (ibd) involves the inflammation of mucosa in the small and large intestine. in ibd, two conditions persist, for example, ulcerative colitis (uc) and crohn 's disease (cd). in uc thus, there is need of development of drug delivery to both conditions at a time. the formulation design to treat cd will also be beneficial to treat uc. a drug, only in its dissolved form, can be absorbed into stomach and intestine. the viscosity of the colonic contents is very high which impede dissolution of poorly water soluble drug [13 ]. the absorption variability in the tmax is very high (30600 min.) in the patient. budesonide, bcs class ii, with a logp of 3.2, is practically insoluble in water (28 g / ml) at physiological ph in the intestinal region, which may be the rate limiting for the dissolution and therapeutic potential of budesonide. the objective is to improve the solubility of budesonide to decrease variability found in tmax. moreover, bioavailability is only about 20% due to first pass effect. we can minimize variability in cmax and tmax by improving the solubility so that the drug concentration can reach faster to their minimum effective level concentration (mec) for therapeutics efficacy. purpose of the research was to prepare bud - pxm solid dispersion, as a formulation exhibiting improved aqueous solubility, which may decrease variability in cmax and tmax in ibd patients, and to study the combined influence of the independent variables (1) ratio of eudragit s100 and eudragit l100 and (2) percentage coating on the dependent variables y1 (time required for 50% drug release at ph 6.8), and y2 (time required for 100% drug release at ph 7.4). the budesonide (bud) was a gift sample from symbiotec pharma lab, indore, india. polyvinylpyrrolidone k30 (pvp k30), croscarmellose sodium (ccs), sodium starch glycolate (ssg), lactose monohydrate, and dibutyl phthalate (dbp) were purchased from s. d. fine chem. the study was carried out by adding excess of drug solution in different solvents, for example, water and phosphate buffer ph 6.8. after 24 hr, supernatant liquid was taken and filtered through whatman filter paper (0.45). the amount of budesonide dissolved was quantified by taking supernatant and by making dilution (if required) using uv 1800 (shimadzu) spectrophotometer at 249 nm. solid dispersions of bud were prepared by fusion or melting method. the ratio of bud - to - polymer (1 : 1) was dispersed in the melted poloxamer at 55c. the resultant mixture was immediately cooled to using an ice - water mixture for 2 h. then mass was allowed to attain at temperature (2530c) and stored at room temperature for 24 h. it was pulverized using a glass mortar and pestle and this mass was sifted through a # 120 sieve. it was transferred to glass vials and stored at 30c 1c and the yield was determined using following formula : (1)yield = ab+c100, where a is the weight of the solid dispersion sifted through sieve, b is the weight of bud taken for solid dispersion, and c is the weight of various carriers taken for solid dispersion. the ratio was selected according to maximum solubilization capacity of drug - to - pxm ratio. the ratio of each of solid dispersions was also characterized by fourier transform infrared spectroscopy (ftir). drug and excipients were mixed geometrically and then granulated using pvp k30 as binder in isopropyl alcohol (ipa). dried granules were passed through 22 # sieve and the fines were separated using 44 # sieve to obtain 2244 # granules. these granules were then lubricated with magnesium stearate (1%) and talc (2%). the statistical design was used to study the combined influence of the effect of independent variables like ratio of eudragit s100, eudragit l100 (x1), and percentage coating (x2) on the dependent variables like time required for 50% drug release at ph 6.8 (y1) and time required for 50% drug release at ph 7.4 (y2). in this design, 2 factors are studied, each at 3 levels, and experimental runs are performed at all 9 possible combinations [6, 7 ]. a statistical model incorporating interaction and polynomial terms is used to evaluate the response : (2)y = b0+b1x1+b2x2+b12x1x2+b11x12+b22x22, where y is the dependent variable, b0 is the arithmetic mean response of the nine runs, and b1 is the coefficient for the factor x1. the main effect (x1 and x2) represents the average result of changing one factor at a time from its low to high value. the interaction terms x1x2 show how the response changes when 2 factors are simultaneously changed. coating solution was prepared using different ratios of material like eudragit l100 and eudragit s100. required quantities of polymers were dissolved in mixture of solvents of 5 ml acetone and 5 ml isopropyl alcohol and stirred with magnetic stirrer to get homogeneous coating solution. dibutyl phthalate was added in above solution as plasticizer (10% on dry polymer based) after getting homogeneous coating solution ; coating was done by dipping the tablet in coating solution till desired percentage coating level was achieved and solvent evaporated. the percentage coating was calculated by the following equation : (3)% weight gain = wtwowo100, where wt is weight of tablet after coating and wo is initial weight of tablet. ftir spectra of the bud, pxm, and solid dispersion were recorded using a fourier transform infrared spectrophotometer (ftir - atr system by bruker alpha with opus - software). samples were prepared using kbr (spectroscopic grade) disks by means of hydraulic press. dsc spectra of drug and its carrier were recorded in dsc shimadzu 60 with tda trend line software. sample of each of 10 mg was accurately weighed using sartorius mc5 electronic microbalance, sealed in aluminium dsc pans, and placed in the dsc chamber. thermal traces were obtained by heating from 50c to 300c at heating rate of 10c per minute under nitrogen atmosphere (100 ml / min) in empty crucibles. about 100 mg of sample was sprinkled over glass slide containing grease to make a layer having thickness of ~0.5 mm. the study was performed by an x - ray diffractometer (panalytical, xpert - pro, new zealand). an x - ray beam (cu target x - ray tube) of 2 kv was allowed to fall over the sample. as the slide moves at an angle of theta degree, a proportional detector detects diffracted x - rays at angle of 2-theta degrees. the drug content of solid dispersion was determined by dissolving 40 mg weighed dispersion in 100 ml phosphate buffer ph 6.8 followed by agitation with a magnetic stirrer for 15 minutes to extract the drug. after filtration through whatman filter paper (0.45), the drug concentration in the phosphate buffer ph 6.8 was determined using uv 1800 (shimadzu) spectrophotometer at 249 nm for budesonide : (4)% drug content = calculated drug concentrationtheoretical drug concentration100. various micromeritic parameters like angle of repose, bulk density, tap density, carr 's (compressibility) index (ci), and hausner 's ratio were measured. 10 tablets were taken and their thickness and diameter were measured by using vernier callipers and average of the diameter and thickness was calculated. 20 tablets were weighed separately using digital electronic balance and the test was performed according to the official method in indian pharmacopeia 2010. hardness indicates the ability of a tablet to withstand mechanical shocks while handling of it. three tablets were randomly picked from batch and analyzed for hardness. the mean and standard deviation were also calculated. the tablet equivalent to 6.5 g was taken and this test was performed using the roche friabilator. friability can be determined by following equation : (5)% friability = initial wt. of tabletswt. of tablets after testinitial weight of tablets100. each tablet was crushed individually and added into 100 ml volumetric flask containing 5 ml methanol and 25 ml phosphate buffer ph 6.8. it was sonicated for 5 min and volume was made up to 100 ml with phosphate buffer ph 6.8. the solution was filtered through 0.45 m whatman filter paper. the filtrate was suitably diluted with phosphate buffer ph 6.8 and analyzed by uv 1800 (shimadzu) spectrophotometer at 249 nm. coated tablets containing equivalent to 9 mg of bud were used for the dissolution studies. the study was performed using usp i basket apparatus at 37c 0.5c at 75 rpm. the dissolution media was 900 ml of 0.1 n hcl for 2 hours, acetate buffer ph 4.6 for 2 hours, phosphate buffer ph 6.8 for 3 hours, and ph 7.4 until complete drug release (n = 3). a 5 ml amount of dissolution media was withdrawn at intervals of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 hours. an equal amount of fresh dissolution media was replaced immediately after withdrawal of the test sample. test samples were filtered through a 0.45 m membrane filter (sartorius, hamburg, germany) and suitably diluted. the absorbance of each diluted sample was measured at 249 nm using a double beam uv-1800 spectrophotometer (shimadzu, japan). to get the release mechanism of drug from coated tablets, release study data were subjected to statistical analysis by zero - order, first - order, higuchi, and korsmeyer peppas equations. tablets were evaluated periodically (0, 1, 2, and 3 months) for appearance, content uniformity, and in vitro drug release. the solubility of pure bud in distilled water and phosphate buffer ph 6.8 was found to be 0.085 0.0003 and 0.0429 0.0078, respectively. therefore, a solid dispersion technique using pxm was employed for dissolution enhancement of bud. after the preparation, different ratios of drug - to - polymer like 1 : 1, 1 : 2, 1 : 3, 1 : 4, and 1 : 5, the percentage yield, and drug content were calculated. the percentage drug content was found to be maximum in drug - to - polymer ratio of 1 : 3 which complies with the assay limit. the results of percentage yield and drug content are shown in solid dispersion as in table 4. bud may exist in the solid dispersion in 2 different forms, namely, crystalline and amorphous. the dissolution rate of solid dispersion depends on the proportion of the 2 forms, which in turn depends on the proportion of pxm in the solid dispersion. an enhancement of dissolution of bud because of the proportion of the amorphous form of bud may increase because of increase in weight fraction of pxm up to its saturated solubility [16, 17 ]. the solubility study was done in water in different ratios of bud and pxm. the ratio 1 : 3 showed maximum solubility as compared to other ratios. the solubility decreased beyond 1 : 3 due to increase in proportion of the crystalline form of bud in solid dispersion at higher ratio. the data of saturated solubility of solid dispersion are shown in table 4 and ftir of optimized solid dispersion as shown in figure 1(c). the ftir spectrum of bud, pxm, and solid dispersion is shown in figures 1(a), 1(b), and 1(c), respectively. the characteristic peaks of pure bud at 3491.69, 2955.97, 1720.30, 1666.39, and 888.48 cm are assigned due to stretching of o h, c h, c = o, c = c, and c h (aromatic ring) groups. the pxm exhibits characteristic peaks at 3503, 2884, and 1114 cm due to stretching of o h, c h, and c o groups. h, c = o, and c = c is the important characteristics of pub. the characteristic stretching bands of pure drug and pxm were shifted at 2878, 1712, and 1097 cm in ftir spectra of optimized batch sd3. shifting of the peak intensity clearly indicates the interaction of drug with carriers due to strong or weak h - bond formation which improves dissolution. in physical mixture (figure 1(d)) of bud and pxm the dsc of budesonide (figure 2(a)) and poloxamer 188 (figure 2(b)) showed sharp endothermic peak at 259.14c and 56.26c which corresponds to melting point of drug and polymer. the dsc of the physical mixture (figure 2(d)) showed two peaks, indicating the melting points of carrier (poloxamer 188) at 54.41c and drug, respectively. in physical mixture, there was no change in peak of drug at 259.14c, which reveals that there is no interaction between drug and carrier. the intensity of melting peak of drug was reduced in physical mixture due to dilution effect. dsc thermogram of solid dispersion (figure 2(c)) of bud with poloxamer 188 in ratio 1 : 3 showed single endothermic peak at 53.49c which is the melting endothermic peak of poloxamer 188 indicating that there is some interaction between polymer and drug which is necessary for the solid dispersion. no melting peak of drug at 259c appeared in this thermogram indicating the complete dispersion of the drug in the carrier polymer due to phase transition. the x - ray diffractogram of pure budesonide (figure 3(a)) clearly showed the peak indicating that the drug is in crystalline form. the peak intensity of drug in solid dispersion (figure 3(c)) was reduced, indicating that the drug was converted into amorphous nature. in the x - ray diffractograms of bud, sharp peaks at a diffraction angle of 5, 10, 11, the solid dispersion showed sharp peaks at 11.7, 16, and 16.5 revealed that some of the crystalline peaks of the drug were still detectable but with reduced intensity and less number in the diffractogram. this data confirms that the little amount of crystalline drug is still present in the solid dispersion although the complete disappearance of its melting peak in the corresponding dsc curves. this indicates that crystallinity of drug is reduced in the solid dispersion which leads enhancement of dissolution of the drug. angle of repose less than 35 indicates good flow property and value of angle of repose for the prepared batch was found in limit which indicates good flow property of granules. the hardness values of formulations were within the range of 3 - 4 kg / cm. friability values of all the formulations were less than 1%. in determination of tablet weight variation, less than 7.5% weight variation is acceptable in the tablet formulation having average weight less than 250 mg. all the formulations were found to be within pharmacopoeial limits as per weight variation test. the content uniformity in all core tablets was found to be within limit of 94.44113.33% which complies with pharmacopoeial limit of 85115%. the coating compositions of factorial batches (b1 to b11) are shown in table 2. the factorial batches were prepared by using independent variables like ratio of eudragit s100 and eudragit l100 (x1) and % weight gain (coating) (x2) and to check its effect on dependent variables like y1 and y2. factorial batches of budesonide were evaluated for the in vitro drug release and by its regression analysis. the cumulative percentage of budesonide release rate for all the formulations (b1 to b11) are shown in figure 4. the dissolution data revealed that, as the ratio of eudragit s100 : eudragit l100 increases, drug release at 7 hour and 10 hour decreases, and as the percentage coating increases, the cumulative drug release decreases. collectively as both the factors, ratio of eudragit s100 : l100, and % coating level increase, it increases the lag time. eudragit s100 is being soluble around ph 7.0 which leads to the formation of pores in the coating layer which allows medium to diffuse into the core tablet and ruptures the outer coat. thus, the level of coating and the concentration of enteric polymer play a very important role for optimizing the formulation. a two - factor, three - level factorial statistical design was employed as the response surface methodology requires 11 experiments. all the responses observed for 11 formulations prepared were fit to quadratic model using design expert software 8.0.7.1. the best fit model was quadratic model and the comparative values of r, adjusted r, predicted r, p lack of fit (lof), adequate precision, s.d., and % cv are given in table 7 along with the regression equation generated for each response in table 9. a positive value represents an effect that favors the optimization, while a negative value indicates an inverse relationship between the factor and the response. it is evident that both independent variables, namely, the concentration of eudragit s100 : eudragit l100 (x1) and % weight gain (x2) have significant effects on the three responses, namely, drug release at 7 hr (y1) and 10 hrs (y2). data given in tables 7 and 8 demonstrates that all the models were significant at 5% confidence level since p values were less than 0.05. the lack of fit (lof) f - test describes the variation of the data around the fitted model. the large p values for lack of fit (> 0.05) p - lack of fit (lof) indicated that the f - statistic was insignificant, which implies significant model correlation between the variables and responses. for all the models, the predicted r value was in reasonable agreement with the adjusted r. adequate precision (ap) compares the range of the predicted values at the design points to the average prediction error. for all response, ratio greater than 4 indicates adequate model discrimination and all predicted models can be used to navigate the design space. the coefficient of variance (cv) is the ratio of the standard error of estimate to the mean value of the observed response defines reproducibility of the model. here, cv value was found to be less than 10% and it confirms that all models are reproducible. the observed value for % cdr at 7 hour for all 11 batches b1b11 varied from 22.69% to 98.67%. the result clearly indicates that y1 is strongly affected by the independent variables selected for the study. the response (y1) obtained at various levels of two independent variables were subjected to multiple regression to give a quadratic polynomial equation : (6)y1=32.3218.80x113.30x212.41x1x2 + 44.44x12 + 1.47x22. as the factor x1 increases, the response y1 decreases and this is indicated by negative coefficient value of dependent variable. these two variables x1 (p < 0.05) and x2 (p < 0.05) were found to be significant in affecting y1. the negative coefficient value for independent variable x1 (18.80) indicates the negative effect on the dependent variable y1, for example, increase in eudragit s100 : eudragit l100 ratio will lead to decrease in % cdr at 7 hour. the negative coefficient value for x2 (13.30) indicates the negative effect on % cdr at 7 hour, for example, increase in eudragit s100 : eudragit l100 leads to decrease in % cdr at 7 hour. the observed value for % cdr at 10 hour for all 11 batches b1b11 varied from 94.44% to 101.26%. the result clearly indicates that y2 is strongly affected by the independent variables selected for the study. the response (y2) obtained at various levels of two independent variables was subjected to multiple regression to give a quadratic polynomial equation : (7)y2=100.492.02x11.57x20.86x1x20.67x120.57x22. as the factor x2 increases, the response y2 decreases and it was indicated by negative coefficient value of dependent variable. these two variables x1 (p < 0.05) and x2 (p < 0.05) were found to be significant in affecting y2. the negative coefficient value for independent variable x1 (2.02) indicates the negative effect on the dependent variable y1, for example, increase in percentage coating will lead to decrease in % cdr at 10 hours. the negative coefficient value for x2 (1.57) indicates the negative effect on % cdr on 10 hours ; that is, increase in percentage coating leads to decrease in % cdr at 10 hour. two - dimensional contour plots and 3d response surface plots are shown in figures 5, 6, 7, 8, 9, 10, 11, and 12 which are very useful to study the interaction effects of the factors on the responses. these types of plots are useful in the study of the effects of two factors on the response at one time. all the relationships among the two variables are nonlinear, although they exhibit a nearly linear relationship as shown in figures 5, 6, 7, 8, 9, 10, 11, and 12. the optimum formulation was selected based on the criteria of attaining the constraints of variables response as shown in table 11. upon trading of various response variables and comprehensive evaluation of feasibility search and exhaustive grid search, batch was considered as an optimum batch hb1 which was composed of coating polymer ratio of eudragit s100 : eudragit l100 (81 : 19) and 6.05% weight gain (coating). another optimum batch hb2 was found to be in the ratio of eudragit s100 : eudragit l100 (23.5 : 76.5) and 9.5% weight gain (coating). for each batch of the coated tablets, three tablets were subjected to the dissolution studies. in vitro dissolution studies these different kinetic equations were applied to interpret the release rate from all the formulations. the best with higher correlation coefficient (r = 0.9489) and (r = 0.9503) was found with first - order drug release. polynomial models including interactions and quadratic terms were generated for all the response variables of coating using multiple linear regression analysis. in order to assess the reliability of the developed mathematical model, formulations corresponding to random compositions of experimental domain were performed. for each of these formulations, the responses were estimated by the use of generated mathematical models and by the experimental procedures. to validate the chosen experimental design and polynomial equations, two additional random batches of coating composition and percentage coating were formulated in experimental matrix to determine the validity of the model generated. subsequently, the result and experimental values of various responses were compared quantitatively with predicted values of responses. the % error (% pe) in prognosis was calculated using the formula : (8)%pe = experimental valuepredicted the compositions of batches covering the entire range of experimental domain are depicted in table 12. tablet enlists the composition of the check - point batches, their predicted values and experimental values of all the response variables, and % pe in prognosis for sustained release. for both the checkpoint batches, the results of dependent variables (y1 y2) were found to be within limits. table 12 showed the composition of checkpoint formulations, their predicted and experimental values for all response variables, and % pe in prognosis. the % pe was calculated as it is helpful in establishing the validity of generated equations and to describe the domain of applicability of rsm model. for validation of experimental design results, the experimental values of the responses hence, these results demonstrate the reliability of the optimization procedure in predicting the effect of process variables. tablets were evaluated periodically (0, 1, 2, and 3 months) for appearance, drug content, and in vitro drug release. no significant changes were observed in any of the study parameter during study period, indicating stability of hb1 and hb2 batch. the present investigation deals with the colon targeting of binary solid dispersion of budesonide and optimization of ratio for coating using eudragit s100 and eudragit l100 and % weight gain. the poloxamer 188 was used as carrier to improve the solubility of budesonide which may reduce patient to patient absorption variability in patients of ulcerative colitis and crohn 's disease. combination of eudragit s100 and eudragit l100 was used for enteric coating and to target the drug to ileum and colon. optimization of coating variables was done using factorial design at 3 levels and 2 factors. from the polynomial equation and contour plots generated, the drug release was delayed until the formulation reach around at ph 6.8 and above which is physiological ph of ileum and colon. thus, the improvement in solubility of budesonide is achieved using poloxamer 188 and colon targeting is achieved using eudragit s100 and eudragit l100. | the purpose of the research was to present budesonide (bud) as a novel formulation showing improved aqueous solubility, which may decrease variability in cmax and tmax found in inflammatory bowel disease (ibd) patients, and drug targeting to colon. to improve aqueous solubility, solid dispersion (sd) of the bud with poloxamer 188 was prepared by melting method. physical characterization of solid dispersion was performed. the sd was used to prepare tablet equivalent to 9 mg of bud. the tablet was coated with enteric polymers eudragit s100 and eudragit l100 to target colon. the ratio of polymers and percentage coating was optimized using statistical design. variables studied in design were ratio of enteric polymers and the effect of percentage coating on in vitro drug release. dissolution at different ph showed that drug release in colon could be modified by optimizing the ratio of polymers and percentage coating. the dissolution data showed that the percentage coating and ratio of polymers are very important to get lag time and optimum formulation. the optimized batch from statistical design was kept under accelerated condition for three months. after accelerated stability study, there was no significant change in the drug release. |
retinopathy, nephropathy, and neuropathy are chronic microvascular complications responsible for much of the morbidity and mortality in type 1 diabetes (t1d). evidence for familiarity in complications has been clearly demonstrated, suggesting a genetic contribution to these phenotypes [14 ]. although numerous linkage and association studies have focused on identifying t1d susceptibility loci, there has been little analysis of genetic influences on complications. in the few linkage analyses that focused on identifying t1d - related complications of susceptibility loci,, there have been no linkage studies aiming at investigating the influence of the hla region on the expression of complications. therefore, the aim of our study was to use the robust method of linkage analysis in a large well - characterized cohort of t1d families to identify gene - loci that predispose to type 1 diabetic complications. we focused our genome analysis on chromosome 6 to follow up our previous work showing the importance of loci on chromosome 6 to the genetic predisposition of t1d complications. families were ascertained through the presence of at least one family member with type 1 diabetes. a questionnaire was given to the proband or parents as well as to additional family members. the questionnaire included demographic, medical, genealogical, and familial information about t1d as well as complications. our dataset included 415 families (2,008 individuals) with t1d cases diagnosed before age 30 (tables 1 and 2). 239 individuals in 159 families had at least 1 microvascular complication : 219 individuals had retinopathy, 87 had nephropathy, and 76 had neuropathy. the accuracy of the self - reported information about complications was evaluated by the following.including extra questions about complications - related conditions in the questionnaire. reports of macular edema, vitrectomy, or complete or partial blindness were considered an indicator of retinopathy ; reports of end - stage renal failure, kidney failure, or repeated high urinary albumin levels were considered an indicator of nephropathy. in cases of inconsistencies (e.g., report of macular edema but not retinopathy), further investigations were carried out through phone interviews. in order to avoid ambiguity, affected.data available from follow - up were used to confirm or update the presence / absence and progression of complications.179 patients had medical records available allowing us to verify phenotype according to american diabetes association guidelines [1114].information indicating absence of a complication in a family member with t1d was considered reliable only if the subject was without that complication for at least 15 years after type 1 diabetes onset. including extra questions about complications - related conditions in the questionnaire. reports of macular edema, vitrectomy, or complete or partial blindness were considered an indicator of retinopathy ; reports of end - stage renal failure, kidney failure, or repeated high urinary albumin levels were considered an indicator of nephropathy. in cases of inconsistencies (e.g., report of macular edema but not retinopathy), further investigations were carried out through phone interviews. in order to avoid ambiguity, only the most obvious or severe cases of retinopathy or nephropathy were classified as affected. data available from follow - up were used to confirm or update the presence / absence and progression of complications. 179 patients had medical records available allowing us to verify phenotype according to american diabetes association guidelines [1114 ]. information indicating absence of a complication in a family member with t1d was considered reliable only if the subject was without that complication for at least 15 years after type 1 diabetes onset. (1) additional questions were included in questionnaires given to both patients and family members. (2) follow - up telephone interviews were carried out by hbdi staff if the questionnaire was unclear. (3) medical records were assessed on t1d patients that submitted medical records with the questionnaire (179 (2.3%)). (4) follow - up questionnaires went to a subset of families for updated information about the development of complications, new cases of diabetes, and other related medical history. twenty - three percent of the type 1 diabetics in the hbdi database responded with follow - up data and 10% of subjects included medical records with the questionnaire. on - going validation at hbdi thus, the severity of reported symptoms, corroboration of accuracy using patients ' medical records, and follow - up contact with a sample of patients and families assure phenotype accuracy. since the majority of patients ' diagnoses are self - reported, t2d may have occasionally been misclassified as t1d. autoantibody markers from a random sample of t1d study subjects (n = 76) characterized study sample homogeneity. only 5% of t1d - classified patients in this subsample tested negative for autoantibodies. also thus, misdiagnosis of t2d as t1d is unlikely to have affected our results. reliability of self - report questionnaires : self - reports of diabetes have demonstrated excellent agreement with the use of medical records. further, other studies have shown that self - reporting of diabetes tends to be more accurate than other chronic disease self - reports [18, 19 ]. we did not identify any studies comparing the use of medical records with self - report of diabetic microvascular complications. thus, if any t1d families were actually t2d, or if some patients with complications were misdiagnosed as complications - free, it is unlikely to have introduced bias into our results for two major reasons. (1) misdiagnosing an affected person as unaffected decreases linkage evidence but does not lead to false linkage evidence ; it introduces reduced penetrance, which the analysis takes account of through the penetrance parameter. (2) classifying a truly unaffected person as affected has the effect of severely reducing the evidence for linkage but can be taken into account via the hlod parameter. strong evidence of linkage, with high lod and hlod scores, does not eliminate the possibility of misdiagnosis or heterogeneity but finding false evidence of linkage because of heterogeneity or misdiagnosis is highly unlikely, since any misdiagnosis degrades the linkage signal. the center for inherited disease research (cidr) at the national human genome research institute did the genotyping. affected phenotypes were (1) the presence of any microvascular complication, (2) the presence of retinopathy, and (3) the presence of nephropathy. the neuropathy phenotype yielded too little linkage information and no further analyses were done using that phenotype. families had at least one affected and one unaffected family member, or at least two affected members (e.g., at least two siblings with t1d, at least one of whom had complications). multipoint lod (logarithm of odds) scores and heterogeneity lod scores (hlod scores) were calculated using the genehunter program. the hlod reflects the evidence for linkage taking into account possible heterogeneity within the dataset ; that is, only a proportion of families in the dataset are linked to the marker. a dominant gene frequency of 0.1 and a recessive gene frequency of 0.2 were assumed. preliminary analyses assuming three levels of penetrance (90%, 50%, and 25%) and a dominant and recessive mode of inheritance showed that a penetrance of 25% and recessive inheritance yielded the highest lod scores [20, 21, 23, 24 ]. subsequently, for all reported analyses, we assumed a recessive mode of inheritance and 25% penetrance. in all calculations, if assuming a recessive mode of inheritance led to positive lod scores, so did assuming a dominant inheritance, indicating evidence in favor of linkage irrespective of assumed mode of inheritance. almost entirely, the lod score assuming a recessive inheritance model was notably higher than dominant, so the lod and hlod assuming recessive inheritance are the scores we report. we performed preliminary analyses on the phenotype any complication but our subsequent analysis classified only subjects with retinopathy (ret) as affected and, separately, only subjects with nephropathy (neph) as affected. therefore, we explored the influence of drb103:01 or drb104:01 on the linkage evidence in subsets of families grouped by the presence of drb103:01 or drb104:01 in the proband. our aim in stratifying was to identify possible gene - gene interaction between the novel loci we identified and these hla alleles, since we had previously identified the alleles ' differential effect on complications risk. we also carried out pure drb103:01 or drb104:01 analyses in which the probands of the selected families carried only the drb103:01/x (x04:01) or drb104:01/x (x03:01) genotype. changes in the lod score profiles in these different subgroups can reflect interaction of that allele with loci linked to the phenotype. with the affected phenotype defined as presence of any complication, a large linkage peak emerged centered in the hla region (5052 cm) ; the lod and hlod scores at 52 cm (hla region location) were 4.0 and 5.3, respectively. two separate, novel loci for complications were located outside the hla region (table 4, figure 1(a)), one telomeric (42 cm) and one centromeric (64 cm) to the hla region. at an assumed penetrance of 0.25, the lod was 2.6 at the 42 cm peak ; the hlod was 4.4. the lod score at the centromeric region (64 cm) was negative, but the hlod score was 2.6 (table 4, figure 1(a)), suggesting linkage in only a subset of the families. the maximum scores at the 42 cm peak for ret were lod = 3.6 and hlod = 5.0 (for any complication, the scores were lod = 2.6 and hlod = 4.4 (compare figures 1(a) and 1(b), table 4)). at the hla locus, the scores for ret were lod = 3.6 and hlod = 5.0, and for any complication, they were lod = 4.0 and hlod = 5.3. the hlod scores at the broad peak around 64 cm were 2.2 for ret and 2.6 for any complication. it is noteworthy that the lod scores at the 42 cm peak increased significantly when including only ret as affected compared with any complication, despite the drop in sample size, that is, excluding nephropathy and neuropathy cases. this suggests that the 42 cm peak does not contribute to the expression of nephropathy or neuropathy. the linkage results in the 45 neph families show 2 peaks : the first peak occurs over the hla region at 52 cm (lod = 1.3 and hlod = 1.4 (figure 1(c))). the second peak is located at the same position (64 cm) as the centromeric peak seen in the any complication and ret analyses. there is evidence against linkage with the neph phenotype at the 42 cm locus that showed strong linkage evidence for ret and any complication. furthermore, with the neph phenotype, the 64 cm peak shows virtually no evidence of heterogeneity (similar lod and hlod values) (lod = 2.0 and hlod = 2.2), suggesting that it is a locus uniquely linked with neph. this suggests that the 42 cm locus is unique to ret and does not influence neph. these two loci appear to have differential influences on ret and neph : one influencing mostly neph (64 cm) and the other influencing only ret (42 cm). we previously showed that the presence of drb103:01 reduced the risk for retinopathy while drb104:01 increased the risk. therefore, we repeated the current analysis subsetting out the ret families in which the proband (a) carried the drb103:01 allele, including those with the 03:01/04:01 genotype and (b) subsetting out those that carried the drb103:01 allele, but excluding those with the 03:01/04:01 genotype (pure drb103:01). we did the two analyses to disentangle the possibly opposite effects on complications of the two different hla - drb1 alleles seen in our previous association analysis. at the 42 cm locus, the unstratified ret analysis (above) had obtained a lod = 3.6 and an hlod = 5.0. the drb103:01 stratification analysis still showed strong evidence for linkage, but the lod and hlod scores decreased (lod = 3.0 and hlod = 3.9), the decrease suggesting only that some families contributing to disease expression have been removed from the data. however, at the 64 cm locus, there was a significant increase in linkage evidence with stratification (lod = 3.1 and hlod = 3.4) on drb103:01 (unstratified analysis was lod = 1.5 and hlod = 2.2). this finding suggests that the 64 cm locus may influence the expression of ret mainly in drb103:01 carriers, suggesting an interaction between drb103:01 and the 64 cm locus. the above stratification analysis included drb103:01 positive probands with the drb103:01/04:01 genotype. because our previous association analysis suggested opposite effects of drb103:01 and drb104:01, we reanalyzed the data excluding drb103:01/04:01 probands, representing a significant reduction in the sample size (see table 3). the 64 cm linkage signal remained prominent in this subset with no evidence for heterogeneity (lod = 2.0 and hlod = 2.2), despite the reduced sample size. in contrast, the peak located at 42 cm decreased substantially with stratification : lod = 0.9 and hlod = 1.6 (unstratified : lod = 3.6 and hlod = 5.0), supporting the protective effect of drb103:01 on ret. we analyzed the ret data using only families of probands carrying the drb104:01 allele, including drb103:03/drb104:01 heterozygotes. the lod and hlod scores at the 42 cm locus in the drb104:01-stratified analysis remained high (4.1 and 4.1, resp.). this suggests that heterogeneous loci contributing to ret were eliminated in the stratified sample (hence the increase in the lod score) but some families contributing to the lod score were also eliminated (thus the decrease in the hlod). at the 64 cm locus, the hlod decreased (hlod = 0.9) compared to the unstratified analysis (hlod = 2.2) ; the lod scores remained negative (unstratified = 1.5 and stratified = 0.5). this is in sharp contrast to the drb103:01 stratification findings, in which the evidence for linkage at the 64 cm locus was notably stronger than in the unstratified analysis. this suggests that the 64 cm locus interacts with the drb103:01 allele to foster the expression of ret but that it does not interact with the drb104:01 allele. when including only drb104:01/x, (x03:01) families, the signal at the 42 cm location remains notable with no evidence of heterogeneity (lod = 2.5 and hlod = 2.5), despite the large drop in sample size (see table 3). at the 64 cm locus, the evidence is against linkage (lod = 1.0 and hlod = 0.0). the stratification analysis results suggest that the 42 cm and the 64 cm loci interact epistatically and differentially with the drb103:01 and 04:01 alleles, revealing evidence of locus heterogeneity for each phenotype. the unstratified analysis of the ret families at the 42 cm locus yields a lod score of 3.6 and an hlod of 5.0, indicating substantial locus heterogeneity in the data. analysis of pure 03:01 families yields a lod < 1 for ret at the 42 cm locus and an hlod that still suggests heterogeneity (hlod = 1.6). 04:01 families yield a lod = hlod = 2.5 at the 42 cm locus. these results suggest that the 42 cm locus interacts positively with the 04:01 allele (to produce ret) and negatively with the 03:01 allele (to protect against ret). furthermore, when only the 04:01 allele is present (and not 03:01), the 42 cm locus shows no evidence of heterogeneity. the drb103:01 stratification analyses suggest that the 42 cm locus influences ret less when 03:01 is present than when 04:01 is present. like the 42 cm locus, the 64 cm locus shows evidence of interaction, but with the 03:01 allele. when stratifying on the 04:01 allele, there is almost no evidence for linkage at the 64 cm locus. in this study, we used, for the first time, lod score linkage analysis to identify loci that contribute to the expression of the microvascular complications of ret and neph. linkage analysis has been shown to have the most power to detect loci important for disease expression and has the greatest ability to give us information about the genetic characteristics of the phenotype and the existence of heterogeneity. the results of the any complication phenotype indicated the existence of three loci. the fact that the hla locus appeared is unsurprising [10, 2631 ] but the discovery of two novel, complications - related loci at 42 cm and at 64 cm was unexpected. there was also significant evidence for the interaction of these two novel loci with the alleles drb103:01 and 04:01. statistically significant evidence for the existence of two loci for complications adds strong support for inherited influences on complications ' expression. both appeared to influence ret expression but the 64 cm locus appeared to influence only neph and the 42 cm locus had no influence on neph. the significant change in the 64 cm locus 's lod score among proband families with drb103:01 strongly suggests that the presence of drb103:01 increases the influence of the 64 cm locus on ret expression. the influence of the 64 cm locus virtually disappears when the proband has the 04:01 allele while the 42 cm peak is strengthened. when proband families are not selected for having a particular hla allele, the observed evidence for heterogeneity is expected if the two hla alleles contribute differentially to the phenotype. the positive differences in the lod scores between the stratified and unstratified samples are strong indicators of interaction of the hla alleles with the two loci. the strong linkage evidence at the hla region (52 cm) might indicate the influence of hla on complications (known from association evidence) or merely cosegregation of hla alleles with diabetes in general regardless of complications. changes in the hla linkage profile under stratification are not interpretable because we artificially altered the hla allele structure by including or excluding specific alleles. however, finding that the drb103:01 and 04:01 alleles interact with the novel loci confirms that hla influences complications ' expression. this study is not without ambiguities.the linkage region we have identified (30 cm70 cm) is a relatively small one for most linkage analyses ; yet we have observed three distinct loci with specific effects. were we analyzing the t1d phenotype and not complications, the lod score at hla would be on the order of 40, thus swamping any other t1d - related signals. however, the narrowness of the region does not nullify the clear separateness of the linkage signals. no matter how the data are stratified and broken down, the consistency of the 42 cm and 64 cm peaks, even when the 42 cm peak disappears (as in the analysis of neph), argues strongly that these loci influence complications ' expression.the number of linkage analyses that we have performed may lead to the question as to whether the lod scores for the two loci we identified should be subject to correction for genome - wide testing. all three peaks appear in the first analysis with notable (2.55) lod scores and/or hlod scores and the locations of these peaks were invariant. the information content of the genotypic data did not fall below 98% across the region. the usual criterion for significance of a lod score (variously debated to be from 2.5 to 4.0) is for genome - wide significance, that is, examining marker loci over the entire genome. however, we examined only markers on chromosome 6, which constitutes only about 6% of the genome and, therefore, the genome - wide cut - off values are too conservative for this analysis. even so, several of the peaks did reach genome - wide significance levels, which became even higher under stratification (i.e., with a smaller dataset). we did not attempt to correct lod scores under stratification because the stratification hypothesis did not concern the existence of a peak but how it changed under stratification. some of those changes would have to be viewed as statistically significant indications of interaction.we used changes in the height of the peaks as indicators of the loci 's influence on complications ' expression. the question of the relative strengths of influence on gene expression as related to linkage peak height is not a well - studied area. linkage will most likely only be observed with loci necessary for disease expression. using the relative lod score changes as indicators of heterogeneity and of interaction is an expansive use of linkage analysis that has been applied to good effect in our studies of autoimmune thyroid disease as well as other diseases. the information inherent in linkage analysis is extremely rich and can be exploited to learn about heterogeneity, mode of inheritance, pleiotropy, and gene - gene interaction.previous work has demonstrated how the stratification technique we used can identify epistatically interacting loci. recent work on detecting interaction has shown that epistasis is easily differentiated from heterogeneity and that false positive indications of interaction are unlikely. however, we can not yet quantify the degree of interaction based on changes in the lod score. also, because of sample size changes, changes in lod scores can not always be unambiguously assigned to changes in interaction. however, an increase in the lod score that accompanies a decrease in the sample size argues for a purification of the sample. the linkage region we have identified (30 cm70 cm) is a relatively small one for most linkage analyses ; yet we have observed three distinct loci with specific effects. were we analyzing the t1d phenotype and not complications, the lod score at hla would be on the order of 40, thus swamping any other t1d - related signals. however, the narrowness of the region does not nullify the clear separateness of the linkage signals. no matter how the data are stratified and broken down, the consistency of the 42 cm and 64 cm peaks, even when the 42 cm peak disappears (as in the analysis of neph), argues strongly that these loci influence complications ' expression. the number of linkage analyses that we have performed may lead to the question as to whether the lod scores for the two loci we identified should be subject to correction for genome - wide testing. all three peaks appear in the first analysis with notable (2.55) lod scores and/or hlod scores and the locations of these peaks were invariant. the information content of the genotypic data did not fall below 98% across the region. the usual criterion for significance of a lod score (variously debated to be from 2.5 to 4.0) is for genome - wide significance, that is, examining marker loci over the entire genome. however, we examined only markers on chromosome 6, which constitutes only about 6% of the genome and, therefore, the genome - wide cut - off values are too conservative for this analysis. even so, several of the peaks did reach genome - wide significance levels, which became even higher under stratification (i.e., with a smaller dataset). we did not attempt to correct lod scores under stratification because the stratification hypothesis did not concern the existence of a peak but how it changed under stratification. some of those changes would have to be viewed as statistically significant indications of interaction. we used changes in the height of the peaks as indicators of the loci 's influence on complications ' expression. the question of the relative strengths of influence on gene expression as related to linkage peak height is not a well - studied area. linkage will most likely only be observed with loci necessary for disease expression. using the relative lod score changes as indicators of heterogeneity and of interaction is an expansive use of linkage analysis that has been applied to good effect in our studies of autoimmune thyroid disease as well as other diseases. the information inherent in linkage analysis is extremely rich and can be exploited to learn about heterogeneity, mode of inheritance, pleiotropy, and gene - gene interaction. previous work has demonstrated how the stratification technique we used can identify epistatically interacting loci. recent work on detecting interaction has shown that epistasis is easily differentiated from heterogeneity and that false positive indications of interaction are unlikely. however, we can not yet quantify the degree of interaction based on changes in the lod score. also, because of sample size changes, changes in lod scores can not always be unambiguously assigned to changes in interaction. however, an increase in the lod score that accompanies a decrease in the sample size argues for a purification of the sample. the next step in this work is to analyze the whole genome, now that we know the importance of stratification loci in identifying interaction. while applying this study 's stratification approach may help us identify the specific genes in the linkage regions using association analysis of snps with retinopathy and/or nephropathy, the option also now exists to use next - generation sequencing to identify the disease - related variants. the difficulty, as with other common conditions, is identifying the disease - related variant if such variants do not occur in exons. replicating our work in other samples however, since the wide adoption of gwas as the genetic technique of choice and the accompanying decrease in the collection of family data, it is not clear how much family data exist for linkage of complications. nevertheless, family studies are the best way to effectively use the newest genetic technologies, and we hope that our findings will inspire a resurgence of family studies for t1d complications and the search for heterogeneity. | we conducted linkage analysis to follow up earlier work on microvascular complications of type 1 diabetes (t1d). we analyzed 415 families (2,008 individuals) previously genotyped for 402 snp markers spanning chromosome 6. we did linkage analysis for the phenotypes of retinopathy and nephropathy. for retinopathy, two linkage peaks were mapped : one located at the hla region and another novel locus telomeric to hla. for nephropathy, a linkage peak centromeric to hla was mapped, but the linkage peak telomeric to hla seen in retinopathy was absent. because of the strong association of t1d with drb1 03:01 and drb1 04:01, we stratified our analyses based on families whose probands were positive for drb1 03:01 or drb1 04:01. when analyzing the drb1 03:01-positive retinopathy families, in addition to the novel telomeric locus, one centromeric to hla was identified at the same location as the nephropathy peak. when we stratified on drb1 04:01-positive families, the hla telomeric peak strengthened but the centromeric peak disappeared. our findings showed that hla and non - hla loci on chromosome 6 are involved in t1d complications ' expression. while the hla region is a major contributor to the expression of t1d, our results suggest an interaction between specific hla alleles and other loci that influence complications ' expression. |
dilate-1 (clinicaltrials.gov : nct01172756) was a double - blind, randomized, placebo - controlled, parallel - group phase 2a study conducted in five centers across austria, the czech republic, and germany. patients received oral placebo or riociguat 0.5 mg, 1 mg, or 2 mg in three subsequent ascending dose cohorts. the following local ethics committees approved the research protocol (eudract number : 2010 - 018436 - 41) : ethics committee of the medical university of vienna and the general hospital of vienna - akh, ethics committee of the a.. hospital elisabethinen, ethics committee for the state of salzburg, ethics committee of the university of prague, and ethics committee of the medical faculty of the university of cologne. eligible patients were those aged 18 years with symptomatic hfpef and ph despite optimized therapy with a stable dose of standard medication for the control of symptoms and risk factors for > 30 days (7 days for diuretic therapy). right - sided heart catheterization was performed by insertion of a balloon - tipped pulmonary artery thermodilution catheter via the right internal jugular vein. hemodynamic and echocardiographic parameters were recorded at regular intervals up to 6 h after intake of study drug. blood samples for pharmacokinetics and exploratory biomarkers were taken at regular intervals up to 24 h after intake of study drug. additional safety follow - ups occurred on days 14 and 30 after study drug administration. the primary efficacy variable was the peak decrease from baseline in mpap, defined as the largest mpap change from baseline up to 6 h after study drug administration. secondary variables included additional hemodynamic and echocardiographic parameters, biomarker levels, safety variables, and pharmacokinetics. for the secondary hemodynamic and echocardiographic variables, the mean change from baseline of all evaluations up to 6 h after study drug administration was calculated. safety was assessed by adverse events (aes), vital signs, and laboratory evaluations, as defined in e - appendix 1. post hoc exploratory estimation of myocardial oxygen consumption (mvo2) was carried out as defined in e - appendix 1. the primary variable was assessed using a two - group, two - sided t test on the riociguat 2 mg group vs placebo at the.05 significance level. exploratory analysis of the secondary efficacy and post hoc variables was via analysis of variance, with treatment and time after study drug administration as main effects and a treatment by time interaction. this was followed by sequential pairwise comparisons between the three riociguat doses and placebo based on least squares means. dilate-1 (clinicaltrials.gov : nct01172756) was a double - blind, randomized, placebo - controlled, parallel - group phase 2a study conducted in five centers across austria, the czech republic, and germany. patients received oral placebo or riociguat 0.5 mg, 1 mg, or 2 mg in three subsequent ascending dose cohorts. the following local ethics committees approved the research protocol (eudract number : 2010 - 018436 - 41) : ethics committee of the medical university of vienna and the general hospital of vienna - akh, ethics committee of the a.. hospital elisabethinen, ethics committee for the state of salzburg, ethics committee of the university of prague, and ethics committee of the medical faculty of the university of cologne. eligible patients were those aged 18 years with symptomatic hfpef and ph despite optimized therapy with a stable dose of standard medication for the control of symptoms and risk factors for > 30 days (7 days for diuretic therapy). right - sided heart catheterization was performed by insertion of a balloon - tipped pulmonary artery thermodilution catheter via the right internal jugular vein. hemodynamic and echocardiographic parameters were recorded at regular intervals up to 6 h after intake of study drug. blood samples for pharmacokinetics and exploratory biomarkers were taken at regular intervals up to 24 h after intake of study drug. additional safety follow - ups occurred on days 14 and 30 after study drug administration. the primary efficacy variable was the peak decrease from baseline in mpap, defined as the largest mpap change from baseline up to 6 h after study drug administration. secondary variables included additional hemodynamic and echocardiographic parameters, biomarker levels, safety variables, and pharmacokinetics. for the secondary hemodynamic and echocardiographic variables, the mean change from baseline of all evaluations up to 6 h after study drug administration was calculated. safety was assessed by adverse events (aes), vital signs, and laboratory evaluations, as defined in e - appendix 1. post hoc exploratory estimation of myocardial oxygen consumption (mvo2) was carried out as defined in e - appendix 1. statistical analyses were performed using statistical analysis system (sas institute inc). the analysis of efficacy was performed in patients valid for per - protocol analysis. the primary variable was assessed using a two - group, two - sided t test on the riociguat 2 mg group vs placebo at the.05 significance level. exploratory analysis of the secondary efficacy and post hoc variables was via analysis of variance, with treatment and time after study drug administration as main effects and a treatment by time interaction. this was followed by sequential pairwise comparisons between the three riociguat doses and placebo based on least squares means. of the 46 patients screened, 39 were eligible for study participation and 36 completed all study examinations (fig 1). a high proportion of patients had comorbidities typical of hfpef, including history of atrial fibrillation (af) (69%), af at baseline (44%), diabetes mellitus (44%), coronary artery disease (17%), and copd (19%). the majority of patients received antihypertensive and diuretic therapy during the study : 47% angiotensin - converting enzyme inhibitors, 36% angiotensin ii receptor antagonists, 44% aldosterone antagonists, 81% -blockers, and 67% loop diuretics (table 2). n = 1 invalid for the pp population because of noncompliance with the protocol (laboratory parameters / ecg assessed before informed consent provided). one patient in the placebo group withdrew because of an ae of pain in the left shoulder. demographic and baseline characteristics data presented are mean (range) or percentage of patients in the per - protocol population. af = atrial fibrillation ; nt - probnp = n - terminal prohormone of brain natriuretic peptide. safety population : placebo, n = 13 ; 0.5 mg, n = 8 ; 1 mg, n = 8 ; 2 mg, n = 10. peak decrease in mpap from baseline up to 6 h after study drug administration in the riociguat 2 mg group vs placebo group (p =.6) (figs 2, 3, e - table 1). however, stroke volume (sv) (p =.04) and cardiac index (p =.001) were significantly increased in the riociguat 2 mg group compared with the placebo group, in the absence of increases in pulmonary arterial wedge pressure (pawp) (p =.9) and significant changes in heart rate (hr) (p =.5) (fig 3, table 3). in parallel, svr (p 20 cm). compared with placebo, there was a significant decrease in right ventricular end - diastolic (rved) area (5.6 cm [95% ci, 10.9 to 0.3 ] ; p =.04) from 23.8 11.5 cm at baseline (97.5 percentile of normal for men > 24.7 cm and women 20.7 cm) with riociguat 2 mg and a decrease in la area (4.0 cm [95% ci, 8.1 to 0.1 ] ; p =.06) (e - table 5). plasma n - terminal prohormone of brain natriuretic peptide, asymmetric dimethylarginine, st2, and galectin-3 revealed no differences in changes from baseline upon administration of riociguat compared with placebo (e - table 6). following single - dose administration of riociguat, plasma concentrations dose - dependently increased across the three active treatment groups (e - fig 1). peak plasma concentrations of riociguat were reached after a median of 1.9 to 2.5 h, and half - life was 13.1 to 14.3 h (e - table 7). details of aes during the study are provided in table 4 ; the majority of aes were of mild or moderate intensity. drug - related serious aes were reported by two placebo group patients (15%) (two cases of decreased co) and three patients (30%) taking riociguat 2 mg (one case of decreased co and three cases of decreased map). the events hemothorax and pulmonary hemorrhage occurred in one patient and relate to the insertion of the right - sided heart catheter. regarding aes of special interest, a fall in invasively measured systemic systolic arterial bp 20 cm). compared with placebo, there was a significant decrease in right ventricular end - diastolic (rved) area (5.6 cm [95% ci, 10.9 to 0.3 ] ; p =.04) from 23.8 11.5 cm at baseline (97.5 percentile of normal for men > 24.7 cm and women 20.7 cm) with riociguat 2 mg and a decrease in la area (4.0 cm [95% ci, 8.1 to 0.1 ] ; p =.06) (e - table 5). plasma n - terminal prohormone of brain natriuretic peptide, asymmetric dimethylarginine, st2, and galectin-3 revealed no differences in changes from baseline upon administration of riociguat compared with placebo (e - table 6). following single - dose administration of riociguat, plasma concentrations dose - dependently increased across the three active treatment groups (e - fig 1). peak plasma concentrations of riociguat were reached after a median of 1.9 to 2.5 h, and half - life was 13.1 to 14.3 h (e - table 7). details of aes during the study are provided in table 4 ; the majority of aes were of mild or moderate intensity. drug - related serious aes were reported by two placebo group patients (15%) (two cases of decreased co) and three patients (30%) taking riociguat 2 mg (one case of decreased co and three cases of decreased map). the events hemothorax and pulmonary hemorrhage occurred in one patient and relate to the insertion of the right - sided heart catheter. regarding aes of special interest, a fall in invasively measured systemic systolic arterial bp 15 mm hg, dpg 7 mm hg), as opposed to isolated postcapillary ph (pawp > 15 mm hg, dpg < 7 mm hg), could be considered for future studies to explore treatment benefits in this population. baseline differences between groups included higher rates of af at baseline in the riociguat 2 mg group compared with placebo and higher lv end - diastolic volume, sv, la area, and right ventricular area in riociguat groups than in placebo. thus, an influence of the extent of remodeling and structural changes on the observed results can not be excluded. the presence of patients with af in the dilate study may have affected the accuracy of hemodynamic measurements. however, this limitation was minimized by the study protocol recommending that investigators use an average of five measurements during thermodilution in patients with af vs three for those in sinus rhythm. hemodynamic tracings and echocardiography were conducted and read on site in accordance with the standards at each institution ; only key echocardiographic parameters were measured to allow for adherence to the protocol - defined acquisition intervals (as short as 30 min), without processing of results for central assessment by core laboratories. there was no significant change in mixed venous oxygen saturation, suggesting that the actual change in co with riociguat was lower than that observed using thermodilution, although direct assessment of oxygen consumption was not performed. furthermore, there were no study - specific standardization procedures regarding end - expiratory capture and analysis of pawp at mid - a ; local standards defined their acquisition. finally, the hemodynamic and echocardiographic effects of single doses of riociguat in this exploratory phase 2b study can not be extrapolated to short - term (weeks) or long - term (months to years) treatment responses. chronic, large - scale, placebo - controlled studies are required, which should include blinded central reading of hemodynamic and echocardiographic measurements. in conclusion, single doses of riociguat were well tolerated and showed favorable hemodynamic and echocardiographic effects in patients with hfpef and ph. riociguat 2 mg significantly increased sv and cardiac index, and decreased systolic bp, svr, and rved area, without altering hr, tpg, or pvr. the ventricular filling required to establish an increased sv was not accompanied by increased pawp, raising the hypothesis that in addition to its systemic vasodilatory effect, riociguat could improve diastolic function. future clinical studies should include the titration of oral sgc stimulators over a longer period of time in patients with hfpef. | background : deficient nitric oxide - soluble guanylate cyclase - cyclic guanosine monophosphate signaling results from endothelial dysfunction and may underlie impaired cardiac relaxation in patients with heart failure with preserved left ventricular ejection fraction (hfpef) and pulmonary hypertension (ph). the acute hemodynamic effects of riociguat, a novel soluble guanylate cyclase stimulator, were characterized in patients with ph and hfpef.methods:clinically stable patients receiving standard hf therapy with a left ventricular ejection fraction > 50%, mean pulmonary artery pressure (mpap) 25 mm hg, and pulmonary arterial wedge pressure (pawp) > 15 mm hg at rest were randomized to single oral doses of placebo or riociguat (0.5, 1, or 2 mg). the primary efficacy variable was the peak decrease in mpap from baseline up to 6 h. secondary outcomes included hemodynamic and echocardiographic parameters, safety, and pharmacokinetics.results:there was no significant change in peak decrease in mpap with riociguat 2 mg (n = 10) vs placebo (n = 11, p =.6). however, riociguat 2 mg significantly increased stroke volume (+ 9 ml [95% ci, 0.4 - 17 ] ; p =.04) and decreased systolic bp (12 mm hg [95% ci, 22 to 1 ] ; p =.03) and right ventricular end - diastolic area (5.6 cm2 [95% ci, 11 to 0.3 ] ; p =.04), without significantly changing heart rate, pawp, transpulmonary pressure gradient, or pulmonary vascular resistance. riociguat was well tolerated.conclusions:in patients with hfpef and ph, riociguat was well tolerated, had no significant effect on mpap, and improved exploratory hemodynamic and echocardiographic parameters.trial registry : clinicaltrials.gov ; no. : nct01172756 ; url : www.clinicaltrials.gov |
production increased nearly 50% from 2008 to 2012.1 increased consumption leading to record production levels has likely been driven by consumer interest in the potential health benefits of blueberries.2 however, availability of new blueberry cultivars with a wider adaptive range has also contributed to the rapid expansion in production. southern highbush blueberry (shb ; vaccinium corymbosum l. interspecific hybrids) cultivars resulting from interspecific hybrids between northern highbush (v. corymbosum l.) germplasm and sources of low - chill traits (usually v. darrowii camp and v. virgatum aiton) have increased production in subtropical locations worldwide.3,4 the university of florida (uf) blueberry breeding program has been developing shb cultivars for over 60 years. as with many horticultural breeding programs, in addition to increasing fruit firmness, two cultivars considered to have a unique crisp texture were selected from this shb germplasm and released from uf in 1997 (bluecrisp)5 and 2005 (sweetcrisp) (lyrene pm, personal communication). many current selections in the uf blueberry breeding program are also considered to have a similar crisp texture phenotype. additional cultivars from other breeding programs that have been described as having crisp texture are dolores and hortblue poppins.6,7 berries with this crisp texture are of particular interest owing to their enhanced eating quality, prolonged postharvest life and potential value for mechanical harvesting for fresh marketed.810 fruit texture is a major factor influencing overall fruit quality. fruit texture affects both the postharvest life of the fruit as well as consumer eating experience.11,12 additionally, owing to rising labor costs and decreasing labor availability for hand harvesting of blueberries, the industry has been looking for ways to mechanically harvest fresh market berries.1,13 new machine harvesters have been designed and tested for use in blueberry,14,15 and research has been initiated to determine cultural practices and cultivars best suited for mechanical harvesting.8,10,16 several bush and berry traits are thought to be desirable for mechanical harvesting methods, and berry firmness is top among them.17,18 fruit texture is determined by several factors governing cellular structure, including fruit anatomy and cellular construction, the mechanical and physiological properties of cells, biochemical changes in the cell wall, turgor pressure and membrane integrity.11 these factors contribute to textural traits such as crispness, hardness, juiciness, and mealiness.11 fruit texture has been measured in a variety of ways, including bioyield tests, deformation tests, tactile assessment, shearing tests, beam tests, measures of juice content and sensory evaluations.11 sensory evaluations are performed by consumers for hedonic characterizations and trained panels are used for profiling and descriptive analysis.19 correlating instrumental measures with sensory evaluations is useful for predicting consumer responses, while using instrumentation is often desirable for quantitative assessments in breeding. previous studies have surveyed firmness and correlated sensory perceptions of texture with instrumental measurements in blueberry, but none using cultivars described as having a crisp texture.12,20 in a survey of 87 highbush and species - introgressed blueberry cultivars, shb cultivars having some v. virgatum or v. darrowii ancestry were among the highest in firmness, based on compression force measurements, suggesting that low - chill species introgression could be a potential source of increased blueberry firmness.21 likewise, shear, compression and bioyield forces were higher in three low - chill rabbiteye cultivars compared with two northern highbush cultivars.20 most recently, bioyield force and strain for 49 blueberry cultivars were measured at harvest and during postharvest storage to develop an index describing the different storage potential of the cultivars.22 however, a weak correlation between compression force measurements and sensory evaluation was found when comparing 12 blueberry cultivars.12 although sensory and instrumental correlation studies have been conducted in other crisp - textured fruits such as grape (vitis spp.) and apple (malus domestica borkh.), crisp texture has not been previously studied in blueberry.2326 the ability to objectively phenotype crisp texture in blueberry is important for breeding purposes to identify parents with crisp texture that can be used in developing advanced selections of higher fresh and postharvest fruit quality and adaptation to mechanical harvest. the objective of this study was to utilize a broad range of shb germplasm, including crisp - textured cultivars and selections, to develop descriptors for textural traits using a trained panel, survey the germplasm for texture differences based on readily available instrumental measurements, and determine the extent of correlation between trained panel ratings and instrumental measurements of the germplasm. the genotypes selected for use in these experiments represented a wide range of germplasm utilized by the uf shb breeding program and included recent cultivar releases, standard cultivars and advanced selections still under trial (supplementary table 1, supporting information). because a primary goal was to develop descriptors for the crisp texture phenotype, approximately equal numbers of crisp and standard - texture genotypes were selected for analyses each year (18 crisp texture and 18 standard texture, and 26 crisp texture and 23 standard texture in 2010 and 2011, respectively). for this initial grouping, the determination between crisp and standard texture was a subjective decision made by the blueberry breeders after several years of observation. cultivars and selections of southern highbush blueberry were hand harvested from field trials near archer, waldo and windsor, fl. berries were collected on six dates (5, 10, 13, 17, 19 and 24 may) in 2010 from 36 genotypes and on seven dates (18, 25, 27 april, and 2, 5, 9, 11 may) in 2011 from 49 genotypes as fruits ripened during the harvest season (supplementary table 1). because of the short harvest window in florida blueberry production (april may, with an approximately 4- to 6-week harvest period for a given genotype), and the limited number of plants available for many of the advanced selections within the breeding program, the number of replicated genotypes within a growing season that could be provided to a trained panel was limited. therefore, we adopted a strategy that allowed multiple genotypes to be evaluated by the trained panel while including standard cultivars and selections that could be evaluated multiple times by the panel. to evaluate panelists ' reproducibility in sensory evaluations and the potential changes in instrumental evaluations, six genotypes (fl 98325, emerald, farthing, sweetcrisp, springhigh and star) replicated on two different harvest dates within the 2010 and 2011 season were compared. only mature, fully blue, unblemished berries were harvested. berries were packed in 170 g plastic vented clamshells (pactiv, lake forest, il, usa), stored in coolers filled with ice and transported on the same day to the usda - ars research lab in winter haven, fl, for sensory evaluation and to the blueberry breeding lab at uf in gainesville, fl, for instrumental analyses. at both locations, berries were stored overnight in a cold chamber at 4 c and brought to room temperature on the next morning before sensory and instrumental analyses were performed. thirteen panelists trained to evaluate fruit and fruit products met in four (2010) and six (2011) 1 h sessions to discuss texture descriptors. using previous definitions for texture adopted for consumer evaluations of blueberry fruit as a starting point,12 we developed blueberry texture descriptors for our unique crisp texture plant material by a trained panel. bursting energy = impression from the first bite, from mushy to crisp / crunchy ; firmness during chewing = firmness between the molars, from soft to firm ; skin toughness = amount of residual skin that needs chewing after the flesh is gone, from tender / thin skin to tough skin ; graininess = texture from stone cells or seeds, from smooth to gritty / grainy ; juiciness = amount of juice from the flesh, from not juicy to juicy ; mealiness = pasty, dry feeling in the mouth, from not mealy to mealy ; overall flavor intensity = blueberry, each descriptor was rated on an 11-point scale (010). to compensate for fruit - to - fruit variability, panelists were instructed to taste two berries at a time, and repeat at least twice. six to eight berries were presented in 120 ml souffl cups with lids (solo cup company, urbana, il, usa), labeled with three - digit number codes and served at room temperature. six and five samples were presented per session in 2010 and 2011, respectively, with two sessions per day. tasting took place in booths under red lighting ; spring water and unsalted crackers were provided to panelists to rinse their mouth between samples. to assess panelist reproducibility and cultivar stability within a harvest season and between years, five cultivars and one numbered selection were evaluated on 2 days with three and two replications on each day in 2010 and 2011, respectively. compression and bioyield force were measured on 25 berries from each cultivar in 2010 and 2011. for compression measurements, berries were oriented equatorially upright, on a firmtech 2 (bioworks, wamego, ks, usa) fitted with a 3 cm diameter flat - bottom plate load cell.21 the point of compression was marked with a permanent marker, and the same berries were rotated 90 along the equatorial plane and punctured with a 4 mm probe in 2010 and a 3 mm probe in 2011 using an instron texture analyzer (instron corporation, canton, ma, usa). compression firmness (n mm) measured the average force required to compress the berry 2 mm. (n) was measured as the maximum force required to puncture a berry at a speed of 50 mm min. panelist discrimination, reproducibility and consensus with panel were assessed using senpaq v.5.01 sensory software (qistatistics, ruscombe, reading, uk) for the data from the six replicated genotypes included each year (supporting information). one panelist was removed from the analyses both years for lack of discrimination for some attributes, lack of reproducibility and inconsistency with the rest of the panel. the means across replications (for replicated samples) and panelists were used to perform a principal component analysis (pca) using xlstat (addinsoft, paris, france). sensory and instrumental measurements of genotypes were analyzed using the mixed procedure using sas 9.2 (sas institute, cary, nc, usa) to detect differences in the measurements of a single genotype that was evaluated on two different harvest dates within a season and differences in the measurements of a single genotype that was evaluated in two different years. dates were included as a fixed effect of sensory and instrumental measures and panelists as a random factor of sensory measures. analysis of variance (anova) was performed for all genotypes in 2010 and 2011 using the glm procedure (sas 9.2) with genotype as a fixed effect of instrumental force measurements. to fit a generalized linear mixed model with random effects and unbalanced replication, the glimmix procedure and kenward roger method (sas 9.2) with genotype as a fixed effect and panelists as a random factor of sensory measurements tukey 's honestly significant difference (hsd) test was used to determine significant differences (p 0.05) between genotype means. correlation analyses were performed on the mean sensory and instrumental values using pearson 's correlation procedure (sas 9.2). the genotypes selected for use in these experiments represented a wide range of germplasm utilized by the uf shb breeding program and included recent cultivar releases, standard cultivars and advanced selections still under trial (supplementary table 1, supporting information). because a primary goal was to develop descriptors for the crisp texture phenotype, approximately equal numbers of crisp and standard - texture genotypes were selected for analyses each year (18 crisp texture and 18 standard texture, and 26 crisp texture and 23 standard texture in 2010 and 2011, respectively). for this initial grouping, the determination between crisp and standard texture was a subjective decision made by the blueberry breeders after several years of observation. cultivars and selections of southern highbush blueberry were hand harvested from field trials near archer, waldo and windsor, fl. berries were collected on six dates (5, 10, 13, 17, 19 and 24 may) in 2010 from 36 genotypes and on seven dates (18, 25, 27 april, and 2, 5, 9, 11 may) in 2011 from 49 genotypes as fruits ripened during the harvest season (supplementary table 1). because of the short harvest window in florida blueberry production (april may, with an approximately 4- to 6-week harvest period for a given genotype), and the limited number of plants available for many of the advanced selections within the breeding program, the number of replicated genotypes within a growing season that could be provided to a trained panel was limited. therefore, we adopted a strategy that allowed multiple genotypes to be evaluated by the trained panel while including standard cultivars and selections that could be evaluated multiple times by the panel. to evaluate panelists ' reproducibility in sensory evaluations and the potential changes in instrumental evaluations, six genotypes (fl 98325, emerald, farthing, sweetcrisp, springhigh and star) replicated on two different harvest dates within the 2010 and 2011 season were compared. only mature, fully blue, unblemished berries were harvested. berries were packed in 170 g plastic vented clamshells (pactiv, lake forest, il, usa), stored in coolers filled with ice and transported on the same day to the usda - ars research lab in winter haven, fl, for sensory evaluation and to the blueberry breeding lab at uf in gainesville, fl, for instrumental analyses. at both locations, berries were stored overnight in a cold chamber at 4 c and brought to room temperature on the next morning before sensory and instrumental analyses were performed. thirteen panelists trained to evaluate fruit and fruit products met in four (2010) and six (2011) 1 h sessions to discuss texture descriptors. using previous definitions for texture adopted for consumer evaluations of blueberry fruit as a starting point,12 we developed blueberry texture descriptors for our unique crisp texture plant material by a trained panel. bursting energy = impression from the first bite, from mushy to crisp / crunchy ; firmness during chewing = firmness between the molars, from soft to firm ; skin toughness = amount of residual skin that needs chewing after the flesh is gone, from tender / thin skin to tough skin ; graininess = texture from stone cells or seeds, from smooth to gritty / grainy ; juiciness = amount of juice from the flesh, from not juicy to juicy ; mealiness = pasty, dry feeling in the mouth, from not mealy to mealy ; overall flavor intensity = blueberry, each descriptor was rated on an 11-point scale (010). to compensate for fruit - to - fruit variability, panelists were instructed to taste two berries at a time, and repeat at least twice. six to eight berries were presented in 120 ml souffl cups with lids (solo cup company, urbana, il, usa), labeled with three - digit number codes and served at room temperature. six and five samples were presented per session in 2010 and 2011, respectively, with two sessions per day. tasting took place in booths under red lighting ; spring water and unsalted crackers were provided to panelists to rinse their mouth between samples. to assess panelist reproducibility and cultivar stability within a harvest season and between years, five cultivars and one numbered selection were evaluated on 2 days with three and two replications on each day in 2010 and 2011, respectively. data were collected using compusense 5.0 data acquisition and analysis software (compusense inc., guelph, ontario, canada). compression and bioyield force were measured on 25 berries from each cultivar in 2010 and 2011. for compression measurements, berries were oriented equatorially upright, on a firmtech 2 (bioworks, wamego, ks, usa) fitted with a 3 cm diameter flat - bottom plate load cell.21 the point of compression was marked with a permanent marker, and the same berries were rotated 90 along the equatorial plane and punctured with a 4 mm probe in 2010 and a 3 mm probe in 2011 using an instron texture analyzer (instron corporation, canton, ma, usa). compression firmness (n mm) measured the average force required to compress the berry 2 mm. (n) was measured as the maximum force required to puncture a berry at a speed of 50 mm min. panelist discrimination, reproducibility and consensus with panel were assessed using senpaq v.5.01 sensory software (qistatistics, ruscombe, reading, uk) for the data from the six replicated genotypes included each year (supporting information). one panelist was removed from the analyses both years for lack of discrimination for some attributes, lack of reproducibility and inconsistency with the rest of the panel. the means across replications (for replicated samples) and panelists were used to perform a principal component analysis (pca) using xlstat (addinsoft, paris, france). sensory and instrumental measurements of genotypes were analyzed using the mixed procedure using sas 9.2 (sas institute, cary, nc, usa) to detect differences in the measurements of a single genotype that was evaluated on two different harvest dates within a season and differences in the measurements of a single genotype that was evaluated in two different years. dates were included as a fixed effect of sensory and instrumental measures and panelists as a random factor of sensory measures. analysis of variance (anova) was performed for all genotypes in 2010 and 2011 using the glm procedure (sas 9.2) with genotype as a fixed effect of instrumental force measurements. to fit a generalized linear mixed model with random effects and unbalanced replication, the glimmix procedure and kenward roger method (sas 9.2) with genotype as a fixed effect and panelists as a random factor of sensory measurements tukey 's honestly significant difference (hsd) test was used to determine significant differences (p 0.05) between genotype means. correlation analyses were performed on the mean sensory and instrumental values using pearson 's correlation procedure (sas 9.2). in general, shb genotypes will ripen over a 4- to 6-week period. to evaluate the potential changes in sensory evaluations on multiple harvest dates, six genotypes replicated on two different harvest dates within the 2010 and 2011 season springhigh when evaluated on different harvest dates in 2010 (p 0.24, data not shown). p - values from analysis of variance for sensory attributes and instrumental measurements of replicated southern highbush blueberry genotypes evaluated on two harvest dates in 2010 and 2011 each genotype was harvested twice during the optimum maturity period for the genotype. significant statistical differences are indicated by asterisks : significant differences between genotypes were observed for all sensory traits evaluated by the trained panels in 2010 and 2011 (p 0.05, table 1). likewise, compression force measurements were significantly different between evaluation dates for fl 98325 and emerald in 2011 (p 0.09). bioyield force measurements in 2010 were significantly different between evaluation dates for two cultivars (farthing and star, p 0.9). in 2011, emerald was the only cultivar for which bioyield force measurements were significantly different between evaluation dates (p 0.24, data not shown). p - values from analysis of variance for sensory attributes and instrumental measurements of replicated southern highbush blueberry genotypes evaluated on two harvest dates in 2010 and 2011 each genotype was harvested twice during the optimum maturity period for the genotype. a dash () significant statistical differences are indicated by asterisks : significant differences between genotypes were observed for all sensory traits evaluated by the trained panels in 2010 and 2011 (p 0.05, table 1). likewise, compression force measurements were significantly different between evaluation dates for fl 98325 and emerald in 2011 (p 0.09). bioyield force measurements in 2010 were significantly different between evaluation dates for two cultivars (farthing and star, p 0.9). in 2011, emerald was the only cultivar for which bioyield force measurements were significantly different between evaluation dates (p < 0.001). there were significant differences between genotypes for compression and bioyield force measurements in 2010 and 2011 (p < 0.05, tables2 and 3). compression force ranged from 1.58 to 3.03 n in 2010 and from 1.71 to 2.93 n in 2011, with 22 and 20 tukey groupings identified by mean separation in 2010 and 2011, respectively. bioyield force ranged from 1.74 to 5.04 n in 2010 and from 1.00 to 2.48 n in 2011, with 18 and 28 tukey groupings identified by mean separation in 2010 and 2011, respectively. the scale and range of bioyield force measurements was different in 2010 and 2011 owing to the unintended use of different - sized probes, but the relationship of bioyield forces between genotypes within a year was unaffected and therefore correlations of bioyield force with compression force and sensory scores in 2010 and 2011 were comparable. cultivars having the greatest bioyield and compression force measurements were also the same cultivars subjectively identified by breeders at uf to have crisp texture prior to this study. correlations between mean sensory measurements of bursting energy, firmness during chewing and skin toughness were significant at p < 0.001 in 2010 and 2011 (tables4 and 5). mealiness and juiciness were negatively correlated (p < 0.001) in 2010 and 2011. in 2011, juiciness was found to be negatively correlated with graininess (p < 0.05) and to be positively correlated with flavor (p < 0.001) (table 5). compression and bioyield force measurements of all cultivars and selections were correlated with an r value of 0.78 (p < 0.001) and 0.71 (p < 0.001) in 2010 and 2011, respectively (tables4 and 5). individually, compression and bioyield force were highly correlated to sensory perceived bursting energy, firmness and skin toughness, but poorly correlated to perceived juiciness, mealiness, graininess and flavor (tables4 and 5). pearson correlation coefficient (r) values between sensory and quantitative scores for all southern highbush blueberry genotypes (n=36) evaluated in 2010 significant statistical differences are indicated by asterisks : pearson correlation coefficient (r) values between sensory and quantitative scores for all southern highbush blueberry genotypes (n = 47 to 55)a evaluated in 2011 n = 55 for sensory attributes (bursting energy, firmness during chewing, skin toughness, mealiness, juiciness, graininess and overall flavor intensity) ; n = 47 for compression force measurements ; n = 54 for bioyield force measurements. the use of replicated genotypes within a season and across years revealed reproducibility of panelist ratings. further, it showed how a genotype could differ between two harvests using one or the other instrumental measurement, and that change may or may not be perceived by the panelists. for example, fl 98325 had a significant increase in compression force from the first to the second harvest in both years, without significant sensory attribute changes (tables3). variable horticultural management practices between farms and blocks within a farm may have influenced sensory evaluation and instrumental firmness. for example, irrigation differences resulting in different fruit turgor could have been a factor affecting perceived bursting energy and juiciness between replication dates. emerald and springhigh were irrigated by overhead sprinklers on a three day rotation, while fl 98325, farthing and it is unlikely that precipitation was a factor affecting these attributes as rainfall was minimal between evaluation dates, and juiciness increased in the relatively large grouping of crisp texture genotypes with bursting energy, firmness during chewing and skin toughness (figs 1 and 2) may be due to the panelists ' inability to differentiate between them, or to these traits being biologically linked with one another. collectively, there was considerable overlap between tukey groupings for all texture attributes (tables2 and 3). the lack of perceptual differences among genotypes suggests that sensory analyses may be difficult to employ for the phenotypic evaluation of blueberry texture attributes necessary for breeding selection. sensory analyses grouped the cultivars kestrel and raven with the subjectively identified crisp texture genotypes. breeder evaluations of both kestrel and raven have not included them in the crisp texture grouping but, in light of the results from this study, that characterization warrants further examination. it remains unclear whether crisp texture is a new trait or the extreme expression of already characterized traits in blueberry such as firmness and skin toughness. observing segregation patterns from putative crisp texture parents would help to elucidate the genetic basis of these cultivars considered to have a unique texture. analysis of variance of the instrumental measurements revealed a significant year genotype interaction. the use of different - size probes (4 mm and 3 mm in 2010 and 2011, respectively) likely contributed to the significant year genotype interaction for bioyield. however, the same equipment and parameters were used for compression force measurements in both years. the 2010 harvest was delayed by approximately 3 weeks due to unusually cool spring temperatures compared to 2011, and may have resulted in instrumentally measured differences, while the relative yearly differences were not apparent to the trained panel. the significant compression and bioyield force differences found between replicated genotypes within a season may result from changes in management and environmental conditions that can occur rapidly within a growing season. a similar increase in precision over sensory analysis was documented in sweet cherry, where a difference of 0.39 n mm was required before a trained sensory panel could perceive a significant difference in cherry firmness.27 with this potential incongruence between trained panel evaluations and instrumental measures, we used a correlative approach to align trained panel results with common instrumental measurements. in a 2008 study of 12 highbush blueberry cultivars, compression firmness, also measured with a firmtech 2, best correlated with juiciness (r = 0.48), bursting energy (r = 0.44) and texture during chewing (r = 0.33), but was not associated with skin toughness.12 compared to the present study, lower correlation values could be due to differences among panels or experimental design, but probably due to the narrow range of cultivar textures evaluated, which did not include crisp texture cultivars. the objective of this study was to develop descriptors for textural traits in blueberry using a trained sensory panel, and survey a broad range of germplasm, including crisp texture genotypes to detect differences in firmness and the extent of correlation between trained panel rating and instrumental measurements of blueberry texture. we found three descriptors that align sensory evaluation of fruit texture and firmness with instrumental measures that could be used for quantitative measurements during breeding selection. instrumental measures of compression and bioyield forces were significantly different among cultivars and correlated with sensory scores for bursting energy, flesh firmness and skin toughness. the results of sensory and instrumental measures support the distinction of crisp texture and standard texture cultivars in blueberry, and suggest that crisp texture is related to both higher compression and bioyield force measurements and to sensory perception of increased bursting energy, flesh firmness and skin toughness. | backgroundfruit texture is a primary selection trait in southern highbush blueberry (shb) breeding to increase fresh fruit postharvest quality and consumer acceptance. a novel crisp fruit texture has recently been identified among shb germplasm. in this study, we developed a common set of descriptors that align sensory evaluation of blueberry fruit texture with instrumental measures that could be used for quantitative measurements during pre- and postharvest evaluation.resultssensory and instrumental characteristics were measured in 36 and 49 genotypes in 2010 and 2011, respectively. a trained sensory panel evaluated fresh fruit based on five common textural attributes in 2010 and 2011 : bursting energy, flesh firmness, skin toughness, juiciness and mealiness. instrumental measures of compression and bioyield forces were significantly different among cultivars and correlated with sensory scores for bursting energy, flesh firmness and skin toughness (r > 0.7, except skin toughness in 2011), but correlations with sensory scores for juiciness and mealiness were low (r < 0.4).conclusionthe results of sensory and instrumental measures supported the use of both compression and bioyield force measures in distinguishing crisp from standard - texture genotypes, and suggest that crisp texture in shb is related to the sensory perception of bursting energy, flesh firmness and skin toughness. |
from october to january, a widespread deadly outbreak occurred in captive birds belonging to the family turdidae in italy. six adult blackbirds (turdus merula), 6 adult fieldfares (turdus pilaris), 20 adult song trushes (turdus philomelos) and 14 adult redwings (turdus iliacus) were sent to the diagnostics and animal welfare of istituto zooprofilattico umbria e marche for necropsy examination. the mortality rates were 15% for fieldfares, 30% for redwings, 32% for song trushes and 14% for blackbirds. no other species of bird held by these breeders (coccothraustes coccothraustes, alauda arvensis and fringilla montifringilla) died. a commercial low iron (25 mg) balanced diet specifically formulated to encourage singing birds was used. the clinical histories of all the dead birds included anorexia, lethargy and finally dyspnea and death. a full necropsy examination of all dead birds was performed, and representative tissue samples were removed and fixed in 10% neutral buffered formalin for routine histological examination. hematoxylin and eosin, masson s trichrome and perls prussian blue staining were performed. during necropsy, fresh tissue samples from lungs, brain and intestines were collected and subjected to molecular analysis for newcastle disease virus (ndv), avian influenza virus and west nile disease virus. viral rna was extracted from the collected tissues using a qiamp viral rna mini kit (qiagen, gmbh, hilden, germany) according to the manufacturer s recommendation. a 316 bp fragment of the fusion protein gene (f) of ndv was amplified from randomly transcribed cdna using the primers ndvf - for2 and ndvf - rev1. a fragment of gene m of avian influenza virus was amplified using a real - time one - step rt - pcr as previously described by spackman.. two one - step real - time quantitative reverse transcription polymerase chain reaction (qrt - pcr) assays for the simultaneous detection of west nile virus (wnv) lineage 1 and 2 strains were performed. the primers and probe for assay 1 targeted the 5-untranslated region (utr), whereas the amplicon for assay 2 was located in the nonstructural region ns2a, which enables an unambiguous and independent wnv diagnosis based on 2 different amplicons as described previously. moreover, touch imprint (ti) cytology from heart and liver samples were prepared. these specimens were stained with a combination of may - grnwald and giemsa - romanowsky stains, using a method described by pappenheim. contamination of food pellet samples by mycotoxins (aflatoxin b1 aflb1, ochratoxin a ota and zearalenone zea, fumonisin b1, b2 and b3) was investigated. aflb1, ota and zea were examined in a single chromatographic run by high - performance liquid chromatography (hplc) coupled with a fluorimetric detection after purification by an immunoaffinity column (iac) (vicam aoz, milford, ma, u.s.a.). samples were homogenized by preparation of a slurry with water at a ratio of 1:1.6 (w / v) and then extracted with acn. the retention time (rt) was used for identification purposes, while concentrations of samples were calculated by interpolation with a calibration curve. fumonisins b1, b2 and b3 as well also were determined by iac (r - biopharm rhne p31). the feed samples were homogenized by preparation of a slurry with water at a ratio of 1:2.5 (w / v) and then extracted with acn / meoh. the purified extracts were analyzed by triple quadrupole lc - ms / ms (api 3200 qtrap) in mrm mode. for each molecule, two transitions were monitored (quantifier and qualifier). the retention time (rt) and ion ratio (ir) were used for identification purposes, while concentrations were calculated by interpolation with a calibration curve. analysis of heavy metal contaminants in food pellet samples (iron (fe), copper (cu), zinc (zn) and lead (pb)) was determined by atomic absorption spectrophotometry (aas) with an air - acetylene flame after mineralization of the sample. ten grams of sample were incinerated in a muffle at 410 20c for 6 hr. the ashes were treated with 10 ml hno3/h2o 1:1 (v / v). subsequently, the sample was placed again in the muffle at 410 20c until it was reduced to white ashes. the ashes were dissolved in 10 ml of hcl / h2o 1:1 (v / v), and the volume was brought to 100 ml with water. at necropsy, all birds showed moderate to marked congestion and enlargement of the liver and spleen. the liver was found to be dark brown in color in around 10% of the birds. moreover, the heart of some animals appeared enlarged, showing small well - demarcated, pale grayish areas consistent with necrosis. microscopic examination of liver samples showed venous congestion and severe, mainly periportal, parenchymal cell degeneration. yellow / gold to brown granular pigment in the cytoplasm of hepatocytes consistent with hemosiderin was detected in all liver samples (fig. liver with marked brown granular deposits consistent with hemosiderin localized especially in periportal hepatocytes (h - e, 10).). perls s prussian blue staining revealed a variable grade of iron deposits in liver samples. forty percent of birds showed marked iron deposits in periportal (zone 1) hepatocytes ; 50% showed accumulation of iron in periportal and midzonal (zones 1 and 2) hepatocytes ; 10% of birds showed marked panlobular iron deposits accumulation (zones 1, 2 and 3) (fig. 2fig. panlobular storage of large dark blue material considered 257 to be iron deposits associated with severe hepatocytes sideronecrosis (perls prussian blue 258 staining, 20).). blackbirds showed the most severe iron accumulation, while song trushes appeared to be a less affected species. the levels of hemosiderosis in the livers of the investigated species are summarized in table 1table 1.level of hemosiderosis in the livers of four investigated speciesiron deposits inblackbirdsfieldfaressong trushesredwingsperiportal01143periportal and midzonal24611panlobular4100. microscopical examination of heart samples showed acute myocardial necrosis characterized by small groups of eosinophilic and fragmented myocardial fibers in 37% of the birds examined (fig. 3fig. extensive myocardial necrosis characterized by 261 fragmented myocardial fibers and mucoid edema with scant leukocyte infiltration (h - e, 20). perls s prussian blue staining revealed occasionally granular iron deposits in scattered myocardial cells. analysis for newcastle disease, avian influenza and west nile virus showed negative results, as did bacteriological exams. coprological examination of fresh stool specimens revealed coccidian oocysts of the genus isospora in 36% of the birds. touch imprint cytology of heart and liver samples showed microfilariae in 13% of the examined birds. hplc and iac for evaluation of aflb1, ota and zea and fumonisins b1, b2 and b3, respectively, in food pellets showed negative results. analysis of heavy metal contaminants in food pellets by aas revealed the following values : iron 111 mg / kg ; copper 6 mg / kg ; zinc 38 mg / kg ; lead 0.132 mg / kg. liver with marked brown granular deposits consistent with hemosiderin localized especially in periportal hepatocytes (h - e, 10). panlobular storage of large dark blue material considered 257 to be iron deposits associated with severe hepatocytes sideronecrosis (perls prussian blue 258 staining, 20). extensive myocardial necrosis characterized by 261 fragmented myocardial fibers and mucoid edema with scant leukocyte infiltration (h - e, 20). isd is predominantly a disease of avian susceptible species that are highly efficient at absorbing dietary iron and do not downregulate iron absorption sufficiently when fed iron - rich diets [5, 26 ]. isd is characterized by a massive accumulation of iron in the liver until heart failure, ascites, hypoalbuminemia and death occur [3, 12, 23 ]. in toucans (rhamphastidae), mynahs (sturnidae), birds - of - paradise (paradisaeidae), curassows (cracidae), quetzals (pharomachrus species), tanagers and hornbills, hepatic iron overload associated with disease has been previously reported [4, 5, 7, 10, 13, 15, 27 ]. isd in turdus species has not been reported until now. in this report, we described a sudden deadly outbreak in italian birds of the turdidae family. firstly, newcastle disease, avian influenza, west nile fever and bacterial diseases were excluded by pcr and bacteriological exams. considering the change of diet before the deadly outbreak, analyses of commercial diet for mycotoxins and metal contamination were performed. analysis for heavy metal contaminants in food pellet samples showed a higher level of iron than that reported on the food label. in particular, it was three times higher than that recommended for feeding to iron - sensitive species [7, 8 ]. microscopical examination of the liver showed marked accumulation of iron characterized by a progressive involvement of hepatocytes from zone 1 to zone 3. the blackbird seems to be more severely affected, showing marked panlobular iron deposit accumulation. on the other hand, the song trhush seems to be the least resistant species, showing a high mortality despite less marked iron deposition compared with the other investigated birds. however, clinical signs of isd, usually considered expression of chronic liver damage, fibrosis, cirrhosis or neoplasms, were not detected in our birds. conversely, acute liver damage represented by degeneration and necrosis of hepatocytes with iron overload (sideronecrosis) was constantly found. it is likely that the time required for these birds to develop hepatic chronic lesions has been too short and that acute liver and heart failure resulted in sudden death. taken together, the results suggested an outbreak of isd caused by a high iron content in the diet given before the hunting season. since the environmental and nutritional conditions of the three small bird - decoy breeders were uniform, the mortalities that occurred only in blackbirds, fieldfares, song trushes and in redwing may suggest a predisposition of these species to development of isd. captivity - related stress and parasitism found in these birds could be considered possible co - factors triggering isd [3, 19 ]. | abstracta widespread deadly outbreak occurred in captive birds belonging to the family turdidae in italy. the present study was performed on 46 dead birds coming from 3 small decoy - bird breeders in central italy. only turdus pilaris, turdus iliacus, turdus philomelos and turdus merula were affected. no other species of bird held by these breeders died. a change of diet before the hunting season was reported from all breeders. full necropsy of the animals and histological investigations of representative tissue samples were performed. microscopical examination showed marked iron deposits in liver samples. bacteriological investigations and molecular analysis to exclude bacterial and viral diseases were carried out. contamination of food pellet samples by mycotoxins and analysis to detect heavy metal contaminants in food pellet samples were considered. an interesting result was the high iron content found in food pellets. it was higher than that considered suitable for birds, especially for species susceptible to development iron storage disease (isd). taken together, the results suggested an outbreak of isd caused by the high iron content of food given to the birds before the hunting season. the high mortality recorded only in species belonging to the family turdidae suggests a genetic predisposition in the affected birds. |
over the past decade, minimally invasive approaches to mitral valve surgery have been commonly used at many centers around the world with excellent short- and long - term outcomes. there has been great enthusiasm about their performance because they have proven to be at least as good and safe as the standard sternotomy approach, even in elderly patients. a variety of approaches have been reported, aimed at reducing surgical trauma and postoperative morbidity while remaining safe and effective. some approaches have been aided by the use of thoracoscopy, specially designed retractors and surgical clamps as well as special instruments for long - distance knot - tying. the right thoracotomy approach has been the most appealing, for reasons of cosmesis and reduced trauma. however minimally invasive mitral valve surgery (mimvs) is performed, the most important consideration is that the approach must yield results equal to or better than those of the approaches it modifies or replaces. there has been increasing interest in simplifying the operation so that it can be widely applied to benefit patients. this report illustrates a simplified, reproducible minimally invasive approach with optimal access to and exposure of the mitral valve (mv) under direct vision. we applied this approach to all patients with moderate and severe mv insufficiency and/or stenosis of various etiologies, with no concomitant coronary artery disease or aortic valve regurgitation. even complex repair procedures for severe bileaflet prolapse in patients with barlow s disease can be successfully performed through this approach. mv surgery using any commercially available prostheses can be performed with the same reliability in patients in whom the mitral valve is not amenable to repair. it is also a useful alternative for patients requiring mv procedures after a previous cardiac operation, particularly in those with patent coronary artery bypasses or previous aortic valve replacement. this may also be applied in patients who had had surgeries via right thoracotomy approach. assessment of mitral valve lesions the degree of mv insufficiency or stenosis is estimated by means of standard echocardiographic measurements. assessment of mv function includes measurement of the mitral annulus, evaluation of leaflet mobility and coaptation, determination of mitral valve orifice area, mitral flow assessment using continuous wave doppler, and valve anatomy evaluation as to valve thickness and pliability and morphology of the subvalvular apparatus. standard guideline in mimvs using the simplified approach because the mitral valve is a posterior structure, excellent exposure can be established through the right anterolateral thoracotomy. a simplified right anterolateral thoracotomy approach includes a 10 - 12 cm incision, either direct aortic or peripheral arterial cannulation and direct bicaval canulation, with standard retractors. under general anesthesia using a double lumen endotracheal tube, the patient is placed in left lateral position with the chest elevated to about 45 - 60 (figure 1a). the right arm is placed over the head at approximately 120 with the elbow joint in the right - angle position. the operating table is rotated leftwards and the patient is bent at the 12 thoracic vertebra. transcutaneous defibrillation pads (philips multifunction electrode pads, philips, amsterdam, the netherlands) are placed at the left lateral chest wall and right shoulder. a 10 - 12 cm skin incision over the fifth anterolateral intercostal space is made beginning in the skin fold below the right breast (figure 1b). the right lung is deflated and the chest cavity is entered without division or resection of any bone. standard chest retractors are used and, under direct vision, the pericardium is incised parallel and approximately 3 - 4 cm anterior to the phrenic nerve. this provides optimal and excellent visualization and access to the ascending aorta and superior vena cava. heparin is administered and arterial cannulation is performed either directly in the ascending aorta or in the common femoral artery (only in patients with a small and narrow chest) with direct bicaval cannulation with caval snares (figure 1c). adequate myocardial protection is achieved with intermittent blood cardioplegia through a cardioplegia needle in the aortic root. the ease and handling of myocardial protection provides no difficulty and is comparable when the approach is through a standard median sternotomy. after clamping the ascending aorta with a straight clamp having a flexible handle, the left atrium is opened by incising the interatrial groove with a vent cardiotomy sucker placed directly towards the left pulmonary veins. a retractor is placed to elevate the interatrial septum, exposing the mitral valve, and the valve is meticulously inspected to determine the precise nature of the lesion. leaflet coaptation is assessed with transvalvular saline injection under pressure. using a nerve hook, leaflet coaptation and the presence of sufficient tissues along the coaptation plane depending on the results of this evaluation, mitral valve repair or replacement is performed under direct vision, using precisely the same approach as in a conventional median sternotomy. modified gerbode plication plastic is applied for posterior leaflet prolapse, ruptured chordae and in ischemic mitral insufficiency (mi). prolapse can occur anywhere along the posterior leaflet but is most commonly found in the region of p2, which may lead to chordal rupture.in this technique, the flail segment is plicated towards the left ventricle in a v - shaped fashion with interrupted mattress sutures using double - ended 3 - 0 polypropylene with untreated autologous pericardial pledgets. when competence and size are satisfactory a strip of untreated autologous pericardium is sutured continuously onto the posterior annulus without further annular narrowing. modified paneth - hetzer posterior annulus shortening technique this is performed by running a pericardial - pledgeted 3 - 0 polypropylene suture through the fibrous body of the trigone and tying it. then it is run along the annulus from one trigone towards the middle of the posterior annulus. these sutures are then tied over an appropriately sized ziemer - hetzer valve sizer to prevent over - narrowing of the valve orifice. then, with a continuous suture, the pericardial strip is attached to the posterior annulus from the midsegment towards the trigone. the leaflet coaptation is tested by a forceful injection of saline through the valve, to look for residual regurgitation. we also use this technique in anterior leaflet prolapse ; the then wider coaptation plane will eliminate prolapse. evaluation of the adequacy of repair after mv repair, it is obligatory to assess the valve function before closure of the atrium and separation from cardiopulmonary bypass (cpb). any remaining areas contributing to significant incompetence must be attended to before closure of the atrium. once de - airing has been completed and extracorporeal circulation is discontinued, the repair result must be further evaluated with intraoperative transesophageal echocardiography (tee) in order to test for inadequate mitral opening area, residual incompetence, myocardial ischemia due to coronary kinking and presence of the systolic anterior motion (sam) phenomenon. immediate and prompt correction must be made if the repair is shown to be unsatisfactory. regardless of the underlying pathology and techniques used, no patient should be discharged from the operating room with more than minimal mi. mitral valve replacement if it is established that the mitral valve lesion is not amenable to repair, the valve is replaced, with either a mechanical or biological prosthesis, in accordance with the patient s wishes. in both procedures, no specially designed instruments are required, and the knots may be tied by hand or with a knot pusher. several strategies of knot tying have been learned with experience, such as having the assistant hold up the annular sutures during knot tying. after completion of the procedure, the left ventricle is vented with a catheter positioned across the valve and the atriotomy is closed. caval snares are snugged tight when tricuspid valve reconstruction (double - orifice - valve technique) or closure of patent foramen ovale are performed, and these procedures are done through right atriotomy. throughout the procedure, a vacuum - assisted venous drain in the heart - lung machine is used and carbon dioxide is infused into the operative field to decrease the chance of air embolism. complete evacuation of intracardiac air is performed through the aortic root and left atrium and confirmed by tee. defibrillation, when necessary, is administered through the external defibrillator pads. once the hemodynamic status is stable, cardiopulmonary bypass is discontinued and decannulation is performed. transesophageal echocardiography is mandatory at the moment to document the repair results or prosthetic function. the right pleural space and mediastinum are drained through the 7 intercostal space with two chest tubes and the intercostal spaces are closed with five or six pericostal sutures. this simplified minimally invasive approach to mitral valve surgery with optimal access to all cardiac structures and optimal exposure of the mitral valve under direct vision offers distinct advantages, including direct aortic root and caval cannulation performed with ease and without obscuring the operative field, optimal exposure and overview of the operative field, controlled myocardial protection, and adequate de - airing. although the skin incision is 5 - 8 cm longer than in the conventional minimally invasive technique, besides providing good cosmesis and an acceptable postoperative scar, it outweighs the placement of additional skin incisions for the other cannulae or the aortic clamp, and obviously avoids the potential complications related to femoral vessel cannulation. additionally, standard aortic cross - clamping and antegrade cardioplegia delivery obviate the need for specialized endovascular occlusive balloons, hence avoiding the potential complications associated with balloon malposition or migration. this simplified approach combines good cosmesis with optimal exposure of the mitral valve and all the cardiac structures, is readily applicable and is not associated with a steep learning curve because one employs conventional cannulation and clamping techniques. | with increasing enthusiasm in minimally invasive surgery, several approaches and access are being performed with great precision. in this report, we illustrate and describe a minimal invasive approach to mitral valve surgery with optimal access under direct vision, the indications and patient selection, the surgical techniques, its advantages over the other approaches, and its simplicity and reproducibility. |
spondyloarthritis (spa) comprise a group of diseases that share certain common features such as spinal, sacroiliac and peripheral joint involvement, presence of enthesopathies, familial occurrence, and a frequent genetic association with the hla - b27 antigen. primary ankylosing spondylitis (as), psoriatic arthritis (psa), spa associated to inflammatory bowel disease (spa ibd), and reactive arthritis are included in this group. furthermore, these diseases may present distinctive articular and extra - articular features. during the last years, some differences between male and female patients with as have been described. the early presentation in male as patients has been discussed, and the higher hla - b27 positivity in the male gender can be associated with this presentation. it has also been observed that female as patients present higher disease activity, higher fatigue scores, and more frequent peripheral involvement. on the contrary, the male gender is associated with more severe radiologic damage and a faster radiologic progression. moreover, women are more likely to present cervical spine involvement, whereas men tend to complain more frequently about lumbar pain. most studies that have assessed gender differences in patients with psa found similar findings to as. women report more frequent peripheral joint involvement and more functional disability, whereas the male gender is associated with axial involvement and more severe radiographic damage. it is important to consider that the clear definition of axial involvement in psa is still a matter of discussion. different proposals have been considered, such as unilateral / asymmetrical sacroiliitis, presence of syndesmophytes, and inflammatory back pain in association with limited movement of the spine. as there are few data regarding gender differences in patients with spa associated with psoriasis and ibd, the present study aims to describe and compare clinical manifestations, disease activity, functional capacity, axial mobility, and radiologic findings between men and women from a multicentric and multiethnic ibero - american cohort of patients with different spa. a total of 2044 consecutive spa patients fulfilling the european spondyloarthropathy study group (essg) classification criteria were included in an observational multicenter international cohort, the respondia registry (registro iberoamericano de espondiloartritis), enrolled between june and december 2006. data were collected by rheumatologists from different ibero - american countries, including argentina, brazil, costa rica, chile, ecuador, mexico, peru, uruguay, and portugal, who used a common protocol of investigation and later transmitted the data on - line to be stored on the database of the spanish spa registry (regisponser), supported by the spanish society of rheumatology. a cross - sectional analysis was performed including only those patients that met modified new york criteria. patients identified as psoriatic spondylitis needed to further have skin disease and fulfill the chandran definition. patients with spa associated with ibd were included if they had crohn 's disease or ulcerative colitis plus axial involvement. socio - demographic data and information related to the disease, such as disease duration (time since first symptom and inclusion in the study), diagnosis delay (time since first symptom and diagnosis), presence of dactylitis, and enthesitis were recorded. disease activity was measured by bath ankylosing spondylitis disease activity index (basdai), functional capacity by bath ankylosing spondylitis functional index (basfi), quality of life assessment was carried out with the ankylosing spondylitis quality of life (asqol) questionnaire, and axial mobility was measured by the bath ankylosing spondylitis metrology index (basmi). for enthesitis, the following anatomic regions were assessed : bilateral first and seventh costochondral joints, fifth lumbar spinous process, anterior superior iliac spines, iliac crests, posterior superior iliac spines, and achilles tendons. radiography studies of pelvis for sacroiliac joints (ferguson view), lumbar, dorsal, and cervical spine were performed at entry, and the radiologic involvement was assessed according to the bath ankylosing spondylitis radiology index (basri). special training and reliability exercise workshops for clinimetric, radiologic, and protocol procedures were performed by site investigators at a national or regional level, and were coordinated by the same experts (ec - e and jv - m). radiography studies of sacroiliac joints were performed according to the routine techniques, but radiograph reading was not centralized. consensus about radiograph reading was reached during the training workshops, prior to the onset of the study. blood samples were obtained from all patients for determination of erythrocyte sedimentation rate (esr) by westergren 's method. finally, work disability was evaluated by direct questioning of the patients and was graded into 3 broad categories : absent, and if present as partial (able to do at least 50% of their work) or total (unable to do any work or permanent labor disability). patients gave written consent and the study was approved by the ethics board of the hospital (named bioethics committee instituto de rehabilitacin psicofsica). categorical data were compared using the x or fisher 's exact test, and continuous variables by anova with levene variance homogeneity test and post - hoc analyses. multiple logistic regressions were performed using the gender as the dependent variable including those variables that had significance < 0.01. models with a classification capacity greater than 80% were included. a value of p < 0.05 was considered significant. categorical data were compared using the x or fisher 's exact test, and continuous variables by anova with levene variance homogeneity test and post - hoc analyses. multiple logistic regressions were performed using the gender as the dependent variable including those variables that had significance < 0.01. models with a classification capacity greater than 80% were included. a value of p < 0.05 was considered significant. from a total of 2044 patients included, 1264 met modified new york criteria ; 73% were male (mean age 42.9 years, sd = 15.8), and 27% female (mean age 45.8, sd = 12.6) (table 1). specifically, 1072 patients had primary as, 147 had psoriatic spondylitis, and 45 had ibd spondylitis. a significant male predominance was detected in as patients (76.2%), whereas no difference was observed in psoriatic or ibd spondylitis (fig. 1). clinical characteristics in the total spondyloarthritis population and according to specific diagnosis (n = 1264). ibd = inflammatory bowel disease, ns = non - significant. overall, male patients were significantly younger, had longer diagnostic delay, lower disease activity (basdai), and better quality of life (asqol), but worse spinal mobility (basmi) and higher radiologic score (basri). presence of dactylitis and enthesitis, as well as swollen joint count, was significantly more frequent among women (table 1). esr was evaluated in 1081 patients and was significantly higher among women compared to men (28.98 mm / h vs 22.84 mm / h, p < 0.001), no additional associations were observed between esr and other disease parameters, including basdai and other patients reported outcomes. determination of c - reactive protein (crp) was not analyzed due to the small number of patients tested and different methods used for measurement. among primary as patients, besides the common characteristics shown by the whole male spa group, basri spine scores were also higher in men compared to women (mean basri spine 7.3 vs 5.8 ; p = < 0.001). analyzing only psoriatic spondylitis, male gender presented less frequent peripheral involvement and worse spinal mobility (basmi), as well as higher basri total and basri spine. patients with ibd spondylitis only differed regarding lateral flexion of the lumbar spine (49.9 10.5 in females vs 35.2 11.1 in males ; p = 0.01). regarding treatment, patients with psoriatic spondylitis used disease - modifying antirheumatic drugs with more frequency (mostly methotrexate and leflunomide), ibd patients used sulfasalazine, and patients with primary as used nonsteroidal anti - inflammatory drugs. given the fact that only 5.7% of the total population was being treated with tumor necrosis factor inhibitors (anti - tnf), no further analysis was considered to be made concerning this topic. regarding work disability in the total spa population, men presented higher permanent work disability (13.2% vs 6.9% ; p < 0.05). this difference persisted among as patients, but no difference was observed between psoriatic or ibd spondylitis (fig. ibd = inflammatory bowel disease, ns = non - significant. spondyloarthritis comprise a group of chronic inflammatory diseases with axial and peripheral involvement which were originally considered as a group of diseases that primarily affected men. in 1949, the male : female ratio was estimated to be 10:1 for as patients ; yet, recent data have established a new 23:1 ratio. according to recent publications and consistent with our findings, there are no differences in the prevalence of psoriatic or ibd spondylitis among men and women ; only a significant male predominance is detected in primary as, associated with more severe axial involvement and radiologic progression. in the present study, the male : female ratio was 3:1 for as, 1.3:1 for psoriatic spondylitis and 1:1 for ibd spondylitis. an interesting finding is that there are significant differences among the genders concerning clinical and radiologic presentation and disease indexes. men were significantly younger, presenting longer diagnostic delay and more severe radiologic damage (measured by total basri). on the other hand, women referred higher involvement of peripheral joints, dactylitis and enthesitis, associated with higher disease activity (basdai) and worse quality of life (asqol). similar data were observed in 1505 patients from the brazilian registry of spondyloarthritis (rbe) and 1514 patients from the spanish spa registry (regisponser), as well as in a british study and in the french desir cohort, which included patients with axial spa of recent onset. the striking observation of a shorter diagnosis delay in females is in contrast to other publications and requires further investigation. first, family history of spa was not analyzed, having been shown that its presence is associated with lower delay, and second, in this cohort women presented worse disease activity (basdai) and quality of life (asqol), which may have driven in a prompt medical consultation. it is worth to note that women reported significant higher indexes of disease activity (basdai), disease functionality (basfi), and quality of life (asqol). a recent meta - analysis about different pain scores associated to the gender in inflammatory arthritis also found a significant higher peripheral involvement in women and axial involvement in men, recommending that future randomized trials and cohort studies recognize the need to evaluate for differential baseline pain levels and responses to treatment according to gender. in the present study, although women referred worse functional involvement and quality of life, male patients presented higher work disability, similar to what has been observed in the north - american psoas cohort. worth to note, although men showed higher permanent work disability in the overall population, they had a higher employment rate at study entry (data not shown). it might be of interest to assess differences in employment rates in these countries according to the gender and if there is a larger interest in men to apply for work in comparison to women. similar to what has been observed in as, female patients with psoriatic spondylitis experienced better spinal mobility and lower radiologic damage. different risk factors have been associated with the development of axial involvement in patients with psoriasis, such as male sex, nail dystrophy, periostitis, radiologic joint involvement, and high esr and crp levels. therefore, it is possible that we had a selection bias in our population and that such bias could be due to the fact that we only used modified new york criteria in the absence of a unified consensus to define axial involvement in psoriatic patients. the new asas (assessment of spondyloarthritis international society) criteria were not available at the time that this study was carried out. regarding work disability, it has been proven in other studies that women with psoriatic arthritis experience higher work disability ; however, a small percentage of patients with axial involvement were included. in a recent study with patients with early psa, short diagnostic delay, preserved function, and male gender were the best predictors of good clinical outcome at 5-year follow - up. a recent systematic review has shown that work disability is high in psa, but the small number of reports and the heterogeneity of the obtained data limit its interpretation. unfortunately, we did not analyze genetic associations among latin - american patients with spa, where native populations are quite heterogeneous in origin. although a small number of patients with ibd spondylitis were included, there were no significant gender differences among them, except for a lesser lateral flexion of the lumbar spine among men. one limitation of our study is that we employed self - administered questionnaires that limited a direct analysis of the impact of work disability and did not give further conclusion. moreover, as determination of hla - b27 was not mandatory for registration into the database and not all centers in latin america had easy access to hla testing, few patients had such test, precluding further analysis. a small number of patients with ibd spondylitis were recruited, probably due to the low prevalence of this disease with axial involvement. the cross section study design did not allow to further gather prospective data of this cohort, which could have resulted in valuable information regarding gender differences in spa along the time. hence, patients with non - radiograhic axial spa, where some gender differences in other studies were recently detected, were not included. it could be argued why basri scoring method was used instead of the modified stoke ankylosing spondylitis (msass) score. furthermore, at the moment of the study the msass scoring method had recently been developed and was not yet worldwide used to assess radiologic involvement. as this study was a cross sectional study, where no longitudinal data were going to be evaluated, the investigators considered that the basri method was a suitable tool. finally, it is important to note that the vast majority of this population was tnf naive, factor that could explain some differences with other recent cohorts that include only anti - tnf - treated patients. we conclude that spa may present different disease expressions according to gender in iberoamerican patients. further longitudinal studies are required to assess genetic background of gender differences in disease expression, especially in multiethnic cohorts like this. | abstractthe aim of the study was to compare clinical manifestations, disease activity, functional capacity, spinal mobility, and radiological findings between men and women from a multicenter, multiethnic ibero - american cohort of patients with spondyloarthritis (spa).this observational cross - section study included 1264 consecutive spa patients who fulfilled the modified new york criteria for ankylosing spondylitis (as). demographic, clinical, and radiologic data were evaluated. categorical data were compared by x2 or fisher 's exact tests and continuous variables by anova with post - hoc tests.primary as was diagnosed in 1072 patients, psoriatic spondylitis in 147, and spondylitis associated to inflammatory bowel disease (ibd) in 45 patients. overall, male patients were significantly younger, had longer diagnostic delay, lower disease activity, worse spinal mobility, better quality of life, and more severe radiologic damage. dactylitis and enthesitis, as well as swollen joint count, were significantly more common among women. in primary as, there was a marked male predominance (76.2%). among patients with psoriatic spondylitis, male predominance was lower (57.8%), but was also associated with worse spinal mobility and more severe radiologic damage. in the total population, male patients with primary as referred higher permanent work disability (13.2% vs 6.9% ; p < 0.05), although no difference was observed in psoriatic or ibd spondylitis according to the gender.among ibero - american spa patients, there are some differences in clinical and radiological manifestations, men showing more structural damage, whereas women more active disease. these data suggest that the phenotype of spa differs between genders. this can influence the subsequent diagnostic approach and therapeutic decisions. |
sleep problems have been one of the most commonly reported health complaints associated with a variety of physical and mental health outcomes (ohayon 2002). according to a global estimate of sleep problems based on 10 different countries (n = 35,327), 31.6 % of individuals suffer from insomnia and 24.0 % report that they do not sleep well (soldatos. in korea, the prevalence of sleep problems ranges between 5.0 and 32.9 % (cho. 2009 ; kim. 2011 ; nomura. 2010 ; ohayon and hong 2002), depending on the characteristics of the population sampled and the definition / case assessment. sleep problems including insomnia, daytime sleepiness, and sleep apnea have been linked to a variety of occupational health issues ; those employees with sleep problems reported an elevated risk of depression and anxiety disorders (motohashi and takano 1995 ; nakata 2011b), alcohol abuse (weissman. 1997), suicide (goldstein. 2008) and chronic pain (kuppermann. 1995) and are considered to be at high risk for hypertension (murata. 2007 ; yang. 2006) and coronary heart disease (mallon. 2002). sleep problems have a profound negative impact not only for individuals but also for the workplace and society as a whole. 2010), increased injuries at work (kling. 2010 ; lombardi. 2010 ; nakata 2011a ; salminen. 2010 ; vahtera. 2006), absenteeism (akerstedt. 2010 ; nakata. 2004b ; philip. 2001), and medical care expenditures (leger and bayon 2010 ; metlaine. 2005). to date, a number of studies have examined the relationship between work organization factors and sleep problems ; these studies have identified overtime work (dahlgren. 2006), job dissatisfaction (nakata. 2004a, 2007 ; scott and judge 2006), overcommitment (kudielka. 2004 ; ota. 2011), high job demands (cahill and landsbergis 1996 ; kalimo. 2000 ; knudsen. 2007 ; nakata. 2007 ; pelfrene. 2002 ; runeson. 2011), role conflict (knudsen. 2007), poor interpersonal relationships (nakata. 2004a, 2007) job insecurity (ferrie. 1998 ; kim. 2011), workaholism (kubota. 2010), and poor social support from colleagues / supervisors (nakata. 2001, 2004a ; ota. 2009 ; pelfrene. 2002 ; runeson. 2011 ; sinokki. 2010), as risk factors for sleep problems, although earlier studies have emphasized the negative impact of non - standard work schedules, that is, shift / night work, on sleep (akerstedt. in addition, emerging workplace issues, that is, workplace bullying (lallukka. 2011 ; niedhammer. 2009 ; takaki. 2010), violence at work (eriksen. 2008), and occupational injustice (elovainio. 2009 ; kim. 2011), are found to be strongly related to sleep problems. although previous studies have suggested that work organization and the nature of work are associated with sleep problems, a few have drawn that conclusion based on representative samples of workers. the data from the national employment survey 20022003, a nationally representative random sample of 1,715 us full - time employees, indicated that work overload and repetitive work were associated with difficulty initiating and maintaining sleep while work overload and role conflict were related to non - restorative sleep (knudsen. in addition, most previous studies used self - administered questionnaires rather than face - to - face interviews, which may introduce reporting / recall bias (bowling 2005). furthermore, little information is available about korean workers ; a study by kim. (2011), which used a self - administered questionnaire, reported that high job demands, insufficient job control, inadequate social support, job insecurity, organizational injustice, lack of reward, discomfort with the occupational climate, and overall job stress were related to a 1345 % increased risk of insomnia (kim. based on the above facts, continued effort is needed to explore the relationship between work organization factors and sleep problems. therefore, this study was undertaken to investigate the relationship between work organization factors and sleep problems in a large nationally representative sample of korean workers using data collected via face - to - face interviews. data were derived from the first korean working conditions survey (kwcs), conducted in 2006 by the korea occupational safety and health agency (kosha) (park and lee 2009). the survey population was a representative sample of the actively working population aged 1565 years (in korea, the legal work age is 15 years). economically active refers to subjects who were either employees or self - employed at the time of interview. therefore, those who were retired, unemployed, housewives, or students were not included in the survey. the basic study design was a multistage random sampling of the enumeration districts used in the 2005 population and housing census (park and lee 2009). data collection was performed by gallup korea during june 26 to september 26, 2006. a total of 36,515 households had dropped out of the interview. the number of households where a member of the household could not be interviewed after visiting 3 times was 14,680, while the number of households where a member of household was encountered but was not qualified to be a respondent was 2,671. the number of households without an employed person aged between 15 and 64 (non - qualified household) was 12,192, and the number of households that refused to take part was 6,972. we excluded workers who were under 18 (n = 4), which resulted in a final sample size of 10,039 respondents. the survey weighting was carried out on the basis of the actively working population, which means that its distribution by age, sex, region, locality, size, economic activity, and occupation is identical to that of the active population distribution. sociodemographic characteristics of the sample and total working population in korea are shown in table 1, suggesting that the distributions of the kwsc and the korean total working population are comparable. the questionnaire contains questions about hours of work, physical risk factors, work organization, and the impact of work on health. the methodology and survey questionnaire of the first kwcs were based on that of the fourth european working conditions survey (ewcs) in 2005 (parent - thirion. 2006).table 1demographic characteristics of the participants in korean working condition survey, 2006sample (%) population (%) age group 15245.47.4 253423.323.7 354432.027.7 455425.023.5 5514.317.6sex men57.958.0 women42.142.0education below middle school19.724.3 high school41.442.4 college / university and beyond38.933.3industry sectors agriculture, forestry and fishing7.48.3 mining and manufacturing21.217.9 construction6.57.9 wholesale and retail trade, hotels, and restaurants19.824.8 electricity, transport, telecom. and finance11.410.0 education8.47.2 other services25.424.0total number10,04323,447,000figures of sample population are weighted demographic characteristics of the participants in korean working condition survey, 2006 figures of sample population are weighted sleep problems in this study were assessed by the single item do you currently suffer from work - related sleep problems (wrsp)? which is identical to the question used in the ewcs. no. descriptions of work organization factors, response options, and response criteria are shown in table 2. in all no about their experiences of discrimination regarding age and sex, sexual harassment, threat of violence, and violence at work during the past 12 months. job insecurity, cognitive work demands, and emotional work demands were measured with a five - point scale. job satisfaction and work - life balance were measured with a four - point scale. social support at work and work intensity were measured by the sum of two items, both with five - point scales. the cronbach s for social support at work and for work intensity was 0.87 and 0.83, respectively. according to the report provided by kosha (park and lee 2006), the test retest reliability for the 1-month interval for the items working at very high speed, working too tight deadlines, and intellectually demanding work had 60.1, 61.7, and 68.5 % consistency rates, respectively.table 2questions regarding work organizational factorsvariablesquestions and response options (in parentheses)response criteriasexual harassmentover the past 12 months, have you been subjected to sexual harassment at work ? (yes / no)yessexual discriminationover the past 12 months, have you been subjected to sexual discrimination at work ? (yes / no)yesage discriminationover the past 12 months, have you been subjected to age discrimination at work ? (yes / no)yesthreat of violenceover the past 12 months, have you been subjected to threats of physical violence at work ? (yes / no)yesviolence at workover the past 12 months, have you been subjected to physical violence at work ? (yes / no)yeswork - life balancein general, do your working hours fit in with your family or social commitments outside work ? (very well, well, not very well, not at all well)not very well, not at all welljob satisfactionon the whole, how satisfied are you with your working conditions in your main paid job ? (very satisfied, satisfied, not very satisfied, not at all satisfied)not very satisfied, not at all satisfiedcognitive demandsyou find your job intellectually demanding. (almost always, often, sometimes, rarely, almost never)almost always, often, sometimesemotional demandsyou find your job emotionally demanding. (almost always, often, sometimes, rarely, almost never)almost always, oftenwork intensity(a) do you work at very high speed ? and [never (0 % of time), almost never (10 % of time), about 25 % of time, about 50 % of time, around 75 % of time, almost all the time (90 % of time), always (100 % of time)]median split : high (36200), low (035)job insecurityi might lose my job in the next 6 months. (strongly agree, agree, neither agree nor disagree, disagree, strongly disagree)strongly agree, agreesocial support(a) you can get assistance from colleagues if you ask for it and (b) you can get assistance from supervisors if you ask for it (almost always, often, sometimes, rarely, almost never)rarely, almost never questions regarding work organizational factors potentially confounding variables were sex, age group (1524, 2534, 3544, 4554, and 55 +), educational level, income per month (3 [1,640.69 ] million korean won), smoking status (never, former, current), and alcohol consumption (number of alcoholic drinks consumed / day, with one drink estimated as about 9 g of pure ethanol). symptoms related to work included depression, anxiety, muscular pain, backache, headache, injuries, stomachache, eyesight problems, skin problems, hearing problems, allergies, and heart disease. other variables included job type classified into 10 categories according to the korean standard classification of occupation (statistics korea 2007), type of employment (employed, self - employed, or employer), working hours per week (3 [1,640.69 ] million korean won), smoking status (never, former, current), and alcohol consumption (number of alcoholic drinks consumed / day, with one drink estimated as about 9 g of pure ethanol). symptoms related to work included depression, anxiety, muscular pain, backache, headache, injuries, stomachache, eyesight problems, skin problems, hearing problems, allergies, and heart disease. other variables included job type classified into 10 categories according to the korean standard classification of occupation (statistics korea 2007), type of employment (employed, self - employed, or employer), working hours per week (3 [1,640.69 ] million korean won), smoking status (never, former, current), and alcohol consumption (number of alcoholic drinks consumed / day, with one drink estimated as about 9 g of pure ethanol). symptoms related to work included depression, anxiety, muscular pain, backache, headache, injuries, stomachache, eyesight problems, skin problems, hearing problems, allergies, and heart disease. other variables included job type classified into 10 categories according to the korean standard classification of occupation (statistics korea 2007), type of employment (employed, self - employed, or employer), working hours per week (300.0581 (5.8)presence of illness no7,561 (75.3) yes2,478 (24.7)employment status employed7,092 (70.6) self - employed or employer2,947 (29.4)income (million korean won / month) 300.01.72 (1.19 2.49)presence of illness<0.001<0.001 no1.001.00 yes81.4 (53.3124.4)82.6 (53.8126.7)type of employment<0.001 employed1.00 self - employed or employer1.64 (1.371.97)job type<0.001<0.001 senior manager1.84 (0.903.67)1.84 (0.824.09) professional / technical1.82 (1.222.73)1.36 (0.872.12) clerical1.001.00 service2.46 (1.623.72)1.67 (1.042.68) sales2.10 (1.343.19)1.38 (0.852.24) agriculture / fisheries4.68 (3.117.05)1.45 (0.892.38) skilled2.14 (1.383.31)0.83 (0.511.34) machine operator3.53 (2.365.28)1.01 (0.641.61) unskilled1.11 (0.671.83)0.64 (0.371.10) armed forces1.03 (0.157.16)0.35 (0.052.73)employment contract0.372 full time1.00 part time1.26 (0.762.01)working hours (hours / week)0.019 < 351.00 35440.81 (0.561.16) 451.47 (1.072.04)work schedule<0.001<0.001 non - shift1.001.00 shift / night2.75 (2.153.52)2.54 (1.863.47)or odds ratio, ci confidence intervalforward stepwise multiple logistic regression analysis (p 0.05 for inclusion and p 0.10 for exclusion) associated factors underlying risk of work - related sleep problems in a representative sample of korean workers (n = 10,039) or odds ratio, ci confidence interval forward stepwise multiple logistic regression analysis (p 0.05 for inclusion and p 0.10 for exclusion) the relationships between psychosocial work characteristics and sleep problems are shown in table 5. univariate logistic regression analyses showed that all 12 organizational variables were significantly associated with a 25525 % increased prevalence of sleep problems. after controlling for covariates, social support at work did not remain significant, but the rest of the 11 variables remained significant.table 5organizational factors underlying work - related sleep problems in the representative sample of korean workers (n = 10,039)organizational factors : n (%) crudep valuemodel ap valuemodel bp valuemodel cp valuesexual harassment9,976 (99.4)no1.00<0.0011.00<0.0011.000.0011.00<0.00163 (0.6)yes6.25 (3.4911.2)6.99 (3.8712.6)3.11 (1.616.00)3.47 (1.776.81)sexual discrimination9,894 (98.6)no1.00<0.0011.00<0.0011.000.0051.000.003145 (1.4)yes3.02 (1.864.91)3.79 (2.316.21)2.27 (1.293.99)2.44 (1.364.36)age discrimination9,696 (96.6)no1.00<0.0011.00<0.0011.00<0.0011.00<0.001343 (3.4)yes3.21 (2.334.42)3.38 (2.444.69)1.94 (1.352.78)2.22 (1.523.23)violence at work9,964 (99.3)no1.00<0.0011.00<0.0011.000.0061.000.03275 (0.7)yes6.09 (3.5510.4)6.01 (3.499.14)2.30 (1.174.16)1.98 (1.063.68)threat of violence9,959 (99.2)no1.00<0.0011.00<0.0011.000.0071.000.03580 (0.8)yes5.27 (3.079.05)5.30 (3.099.14)2.26 (1.254.09)1.96 (1.053.66)work - life balance7,268 (72.4)good1.00<0.0011.00<0.0011.00<0.0011.00<0.0012,771 (27.6)poor3.07 (2.573.68)3.02 (2.513.63)1.96 (1.612.40)1.78 (1.442.20)job satisfaction6,712 (66.9)high1.00<0.0011.00<0.0011.00<0.0011.00<0.0013,327 (33.1)low3.52 (2.904.27)3.44 (2.844.17)1.76 (1.432.16)1.69 (1.372.09)cognitive demands5,365 (53.4)low1.00<0.0011.00<0.0011.00<0.0011.00<0.0014,674 (46.6)high1.79 (1.492.15)1.94 (1.612.34)1.61 (1.311.98)1.64 (1.322.03)emotional demands5,578 (55.6)low1.00<0.0011.00<0.0011.00<0.0011.00<0.0014,461 (44.4)high1.71 (1.422.04)1.90 (1.582.21)1.54 (1.261.89)1.53 (1.221.91)work intensity5,270 (52.5)low1.00<0.0011.00<0.0011.000.0011.00<0.0014,769 (47.5)high2.27 (1.882.74)2.32 (1.922.81)1.44 (1.171.78)1.55 (1.251.92)job insecurity6,540 (65.1)low1.000.0171.000.0151.000.0321.000.0093,499 (34.9)high1.25 (1.041.50)1.26 (1.051.51)1.25 (1.021.53)1.32 (1.071.63)social support at work5,845 (65.9)high1.000.0141.000.1281.000.7181.000.3484,194 (34.1)low1.26 (1.051.51)1.16 (0.961.41)1.04 (0.841.29)0.88 (0.671.15)or odds ratio, ci confidence intervaladjusted for age group, sex, educational level, and incomeadjusted for age group, sex, educational level, income, smoking, drinking, and presence of illnessadjusted for age group, sex, educational level, income, smoking, drinking, presence of illness, type of employment, type of occupation, employment contract, working time, and work schedule organizational factors underlying work - related sleep problems in the representative sample of korean workers (n = 10,039) or odds ratio, ci confidence interval adjusted for age group, sex, educational level, and income adjusted for age group, sex, educational level, income, smoking, drinking, and presence of illness adjusted for age group, sex, educational level, income, smoking, drinking, presence of illness, type of employment, type of occupation, employment contract, working time, and work schedule the purpose of this study was to investigate the relationship between work organization factors and wrsp in a large representative sample of korean workers. first, organizational factors related to violence, discrimination, work - life imbalance, job dissatisfaction, high work demands and intensity, and job insecurity were associated with an increased prevalence of wrsp even after adjusting for an array of potential confounders. second, male gender, age group, presence of illness, and shift / night work were background risk factors associated with high wrsp prevalence. although the results must be interpreted with caution because of the cross - sectional nature of the study design, the analyses of this large population - based representative survey suggest that work organization factors are important risk factors for wrsp among korean workers. those who experienced sexual harassment at work had a 3.5 times higher risk of wrsp compared to those who had not experienced sexual harassment at work. although we could not locate studies specifically focused on a relationship between sexual harassment and workers sleep problems, several studies have reported the relationship between sexual harassment and workers physical and mental health. a study on female flight attendants showed that for those who experienced sexual harassment, the risk of poor self - rated health was 2.8 times higher than for those who had not had such an experience (ballard. there are also reports that sexual harassment heightens the risk of depression, somatic symptoms, posttraumatic stress disorder (ptsd), and other medical conditions (street. sexual harassment also raises the risk of the victims harmful alcohol use (gradus. given such evidence, workers who experienced sexual harassment may have an increased risk for suffering sleep problems. this study found that the participants who perceived sex- and age - related discrimination had more than twice the risk of wrsp than those workers who did not. discrimination is a crucial social issue not only in multiethnic nations such as the united states but also in non - multiethnic nations as well. in the united states, the occurrence of perceived discrimination over one s lifetime is 33.5 %, but the prevalence differs greatly by racial / ethnic group ; for non - hispanic whites, it is 30.9 %, for non - hispanic blacks, 48.9 %, and for other racial / ethnic groups, 50.2 % (kessler. 1999). the results of the 19771989 us longitudinal survey of mature women (n = 1,778) indicated that perceived workplace discrimination ranged between 11.11 and 15.14 % in black women, while it ranged between 12.10 and 16.03 % in white women. workplace discrimination was found to be one of the strongest predictors for emotional distress and functional limitation (pavalko. the occurrence of age and sex discrimination at the workplace was 3.4 and 1.4 %, respectively, which was lower than those of studies conducted in the united states (kessler. 2003), but the impact on sleep seems substantial. taking these findings into consideration, workplace discrimination may have a long - lasting negative influence on sleep behavior, possibly resulting in poor mental health of affected workers. additionally, in this study, those who experienced violence at their work sites were twice as likely to suffer from sleep problems as those who did not. a study of nurses aides revealed that those who had been exposed to threats or violence at work had a 19 % increased risk of poor sleep compared to those without such exposures (eriksen., the experience of violence is known to adversely affect workers health both mentally and physically (rogers and kelloway 1997). even when an individual is not a direct victim of violence, being a witness to a threatening act has been reported to exert negative effects (anxiety, illness symptoms, and negative occupational outcomes) (hall and spector 1991). the result of this study corresponds with the notion and that workers who are exposed to threats of violence had an equivalent risk of sleep problems as those who actually had undergone violence at work. work - life imbalance has become an emerging issue in korea because of an increase in working hours (park. work - family imbalance has been reported to be a risk factor for depression (frone. 1996), reduced well - being (grant - vallone and donaldson 2001), exhaustion (demerouti. 2004), and alcohol abuse (wang. 2010). those who had difficulties combining work and private life had increased odds for sleep disorders (men adjusted or 1.54, 95 % ci 1.122.10 and women adjusted or 1.81, 95 % ci 1.312.49) (hammig and bauer 2009). another study in medical residents showed that work - family conflict was associated with sleep deprivation (geurts. our study found that work - life imbalance is related to increased sleep problems in korean workers as well. job satisfaction has been consistently associated with sleep problems in earlier studies (doi. 1995 ; nakata. 2004a, 2007, 2008 ; scott and judge 2006). for example, scott and judge (2006) reported that insomnia is positively related to job dissatisfaction and this relationship is mediated by hostility, joviality, and attentiveness in us administrative employees (scott and judge 2006). doi. (2003) found that job dissatisfaction is the second major factor for poor sleep quality, which resulted in a twofold increase in the prevalence of disturbed sleep among white - collar employees in japan (doi. another study in japan revealed that low job satisfaction created a significantly increased risk for insomnia including difficulty maintaining sleep (dms) after adjusting for multiple confounding factors (nakata. our study, together with those from other countries, indicates that job dissatisfaction is a risk factor associated with sleep problems. high cognitive and emotional demands, as well as high work intensity, increased the risk of sleep problems. a significant association between cognitive demands and difficulty initiating sleep (dis) was found in male white - collar daytime workers in japan (nakata. (1988) also reported that mental workload was one of the most important factors that interfered with falling asleep (urponen., there is consensus that high job demands are related to insomnia (cahill and landsbergis 1996 ; kalimo. excessive mental / cognitive demands and working too hard may disturb the ability to fall asleep, which in turn may impair the quality of sleep. in our study, social support at work was not associated with sleep problems after adjusting for confounding factors. although the majority of published studies (cahill and landsbergis 1996 ; eriksen. 2011) indicate that poor social support at work is related to sleep problems, some studies suggest that the statistical significance of this relationship is attenuated after controlling for confounders (nakata. this finding may be relevant to the fact that social support often exerts a buffering effect on health outcomes and that the significant relationship disappears if controlled for related variables. however, it is important to note that social support from one s workplace is often more protective than social support from family or friends, suggesting the importance of workplace social support (nakata. 2001, 2004a). a significant association between job insecurity and sleep problems was found in this study. after the 1998 financial crisis in east asia, korea was no exception with regard to increased job insecurity. at the time of the crisis, a large number of workers lost their jobs and since then businesses have not been active in recruiting permanent employees (preferring temporary employees), and employers are facing organizational restructuring over time. workers who feel their jobs are insecure may succumb to sleep disorders resulting in long - term mental stress. a study of civil servants in britain reported that male workers who experienced organizational change tended to have increased sleep problems (ferrie. 1998). another swedish study discovered that workers who expected that they would lose their jobs experienced sleep disturbances (mattiasson. the results of this study support the notion that job insecurity is connected to sleep problems. the overall prevalence of wrsp in this study was 5.1 %, which was comparable to that of 8.7 % in the fourth ewcs (table 3). the sleep problems question used in both the kwcs and the ewcs was targeted specifically to work - related sleep problems. a study in sweden (swedish work environment survey ; swes) used a similar method to define sleep disturbances as both the kwcs and ewcs and showed a strong predictability of medically certified sickness absence (westerlund. the definition used in the kwcs, ewcs, and swes might have a stronger predictive validity than merely asking about general sleep problems because general sleep problems may also capture problems related to or caused by non - work - related issues. however, it is also true that the significant associations found in this study are subject to the triviality trap ; that is the measurement of the independent (wrsp) and dependent (organization factors) variables is conceptually overlapping and the observed associations may be spurious (kristensen 1996). thus, future studies should be undertaken to validate our finding by using objective sleep measures in a prospective study design. the analyses of underlying factors associated with wrsp revealed that men had a 1.5 times higher odds of wrsp than women (table 4). in studies investigating sex differences in sleep problems, the majority of studies discovered that sleep problems are more frequent in women than in men (chen. however, in this study, as the definition of sleep problems was work - related, it may be that working men in korea have more sleep problems due to work than working women do. in the ewcs, the prevalence of sleep problems in men was 8.9 %, while it was 8.5 % in women. thus, it is likely that the higher prevalence of sleep problems in men than in women may depend on how sleep problems are defined. as suggested in table 4, the higher prevalence of wrsp in workers with illness and working the shift / night schedule is in line with previous findings, indicating that the association was in the expected direction. the specific strengths of this study are that : (a) the sample was both nationally representative of the korean working population and was large in size, (b) the study measured a number of work organization factors, (c) the analyses controlled for a broad array of potential confounders related to work organization and sleep problems, and d) the survey measures were collected via face - to - face interviews resulting in very little missing data. a major criticism of the methodology of the present study is that we evaluated wrsp with a single question, which prevented us from judging the severity of sleep problems and did not allow us to compare our results with other studies that used more general questions. moreover, the definition of wrsp may include not only those with general sleep problems, that is, insomnia, poor sleep quality, and sleep loss, but also those with more specific sleep disorders, that is, sleep apnea, excessive daytime sleepiness, severe bruxism, etc. first, the study is cross - sectional in nature ; thus, no causal interpretations can be made. however, it may be speculated that sleep problems affect the rating of work conditions ; workers with sleep problems may have issues with irritability with colleagues and supervisors, an inability to concentrate at work, difficulty accomplishing assigned tasks in a timely manner, and uncertainty that they will be able to continue their employment, leading to expressions of higher work stress (nakata. a two - year prospective study of the effort - reward imbalance model, the job demand - control model, and insomnia revealed that those who were not insomniac at the baseline became insomniac when exposed to high overcommitment to work (or 1.75, p < 0.05) and high job strain (or 1.72, p < 0.05) (ota. 2009). second, most of the work organization measures consisted of single item that may raise questions as to the validity and reliability of the results. however, items such as job satisfaction are known to hold as high a reliability as multi - item scales (wanous. third, even though we have statistically controlled for existing disorders, it is possible that those who are suffering from sleep problems may be affected by comorbid disorders. the specific strengths of this study are that : (a) the sample was both nationally representative of the korean working population and was large in size, (b) the study measured a number of work organization factors, (c) the analyses controlled for a broad array of potential confounders related to work organization and sleep problems, and d) the survey measures were collected via face - to - face interviews resulting in very little missing data. a major criticism of the methodology of the present study is that we evaluated wrsp with a single question, which prevented us from judging the severity of sleep problems and did not allow us to compare our results with other studies that used more general questions. moreover, the definition of wrsp may include not only those with general sleep problems, that is, insomnia, poor sleep quality, and sleep loss, but also those with more specific sleep disorders, that is, sleep apnea, excessive daytime sleepiness, severe bruxism, etc. first, the study is cross - sectional in nature ; thus, no causal interpretations can be made. however, it may be speculated that sleep problems affect the rating of work conditions ; workers with sleep problems may have issues with irritability with colleagues and supervisors, an inability to concentrate at work, difficulty accomplishing assigned tasks in a timely manner, and uncertainty that they will be able to continue their employment, leading to expressions of higher work stress (nakata. a two - year prospective study of the effort - reward imbalance model, the job demand - control model, and insomnia revealed that those who were not insomniac at the baseline became insomniac when exposed to high overcommitment to work (or 1.75, p < 0.05) and high job strain (or 1.72, p < 0.05) (ota. second, most of the work organization measures consisted of single item that may raise questions as to the validity and reliability of the results. however, items such as job satisfaction are known to hold as high a reliability as multi - item scales (wanous. third, even though we have statistically controlled for existing disorders, it is possible that those who are suffering from sleep problems may be affected by comorbid disorders. this study found a significant relationship between a broad range of work organization characteristics and sleep problems, which has been understudied in representative samples of workers. although a prospective study with objective sleep measures is warranted to prevent the triviality trap, the present finding that work organization factors are related to sleep problems may be useful in developing strategies to prevent sleep problems in the korean working population. this article is distributed under the terms of the creative commons attribution license which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. | purposethe purpose of this study was to assess the association of organizational factors with work - related sleep problems (wrsp) among korean workers.methodsthe data were derived from the first korean working conditions survey conducted in 2006 with a representative sample of the korean working population (n = 10,039).resultsthe overall prevalence of wrsp was 5.1 % (95 % confidence interval (ci) 4.75.5). those who experienced sexual harassment at work (adjusted odds ratio (aor) 3.47 : 95 % ci 1.776.81), discrimination due to sex (aor 2.44 : 95 % ci 1.364.36) or age (aor 2.22 : 95 % ci 1.523.23), violence at work (aor 1.98 : 95 % ci 1.063.68), threat of violence (aor 1.96 : 95 % ci 1.053.66), poor work - life balance (aor 1.78 : 95 % ci 1.442.20), low job satisfaction (aor 1.69 : 95 % ci 1.372.09), high cognitive (or 1.64 : 95 % ci 1.322.03) and emotional (aor 1.53 : 95 % ci 1.221.91) demands, job insecurity (aor 1.32 : 95 % ci 1.071.63), and high work intensity (aor 1.55 : 95 % ci : 95 % ci 1.251.92) had an increased risk of wrsp compared to their respective counterparts (p < 0.01). low social support was not significantly associated with wrsp (aor 0.88 : 95 % ci 0.671.15).conclusionthe results revealed that poor psychosocial working conditions may be related to a high prevalence of wrsp among representative korean workers. |
down syndrome (ds), also referred to as trisomy 21, is caused by an extra copy of chromosome 21. occurring in approximately 1 in 800 live births, it is the most common chromosomal abnormality resulting in learning difficulties. the prevalence of alzheimer 's disease (ad) in people with ds increases significantly with age, and dementia in people with ds is one of the most common forms of dementia among individuals under the age of 50 years. despite the occurrence of ad pathology, including amyloid plaques and neurofibrillary tangles, in the brains of individuals with ds as young as 40 years (wisniewski., 1994) the mean aao of dementia is 50 to 55 years (prasher and krishnan, 1993), with a range from 38 to 70 years. the early - onset ad that occurs in people with ds is thought to be largely due to the triplication of app, which is located on chromosome 21. indeed, app duplications have been shown to cause early - onset ad in the disomic population (mcnaughton., 2012 ; rovelet - lecrux., 2006 ; sleegers., 2006), although these are not always fully penetrant (hooli., 2012). as dementia in the ds population can develop over a range of ages, it is likely that, as with sporadic ad in the general population, genetic factors play a major role. although mutations in a small number of genes associated with the production of amyloid, such as app, psen1, and psen2, have been found to cause early - onset ad in the general population, the majority of ad cases are sporadic and are likely to have a complex genetic etiology. apoe is a key genetic risk factor for late - onset ad in the general population (corder., 1993), and large genome - wide association studies (gwas) carried out in recent years have identified further risk genes : clu, picalm, bin1, cr1, abca7, cd2ap, epha1, cd33, and the ms4 locus (harold., 2009 ; hollingworth., 2011 ; naj., 2011 ; seshadri., although we and others have shown apoe to affect ad risk in ds individuals (deb., 2000 ; prasher., 2008 ; royston., 1996), this result has not been replicated in all studies (margallo - lana., 2004 ; van gool., (2011) examined snps in 28 genes associated with ad risk, selected from literature published up until march 2008. no therapies have specifically been developed for the treatment of ad in ds, and, as the life expectancy of people with ds is increasing, it is becoming more important to understand the factors affecting age - related diseases in this population (coppus., 2006 ; holland., 2000). given the almost universal presence of early - onset ad pathology in people with ds, factors affecting aao, severity, and disease progression need closer analysis. this may also provide information relevant to those at risk of developing ad in the general population. in this study, we examined the impact of snps that have recently been associated with ad risk in the general population, in 2 large meta - analyses (hollingworth., 2011 ; naj., 2011), upon aao of ad in people with ds. a total of 158 dna samples were prepared from blood or brain from individuals with ds using a commercially available kit (dneasy blood and tissue kit, qiagen). ninety - four blood samples were collected from two clinical trials (meadows (hanney., 2012), downslit [http://public.ukcrn.org.uk/search/studydetail.aspx?studyid=5927 ]), and 64 brain samples from the newcastle and london neurodegenerative disease brain banks, and thomas willis oxford brain collection, as part of the brains for dementia research initiative, the medical research council alzheimer brain & tissue bank in edinburgh, the nichd brain and tissue bank for developmental disorders, university of maryland (nichd contract no. n01-hd-4 - 3368 and no1-hd-4 - 3383), the alzheimer s disease research center, washington university in st. samples were requested and collected with permission from north west, and newcastle and north tyneside research ethics committees. samples were collected with informed consent using processes approved for each brain bank or by the research ethics committees. the meadows trial examined the use of memantine as a treatment for cognitive decline in ds over the course of 52 weeks. similarly, the downslit trial used lithium to improve cognitive function in ds over the course of 8 weeks. the use of memantine in the meadows trial did not alter the risk of developing dementia or aao (= 0.031, p = 0.861 and t = 0.291, p = 0.745 respectively). there were no differences in gender frequencies between the blood and brain samples cohorts (= 0.013, p = 0.908). individuals in the autopsy cohort were older than those in the clinical cohort (mann whitney u test, p = 0.008). for samples from the clinical trials, aao of dementia was recorded by the trial psychiatrist (m.h.) and the youngest aao was 34 years. the mean duration of dementia before death in people with ds is approximately 5 years (prasher and krishnan, 1993 ; prasher., 2008). for therefore we defined aao as age of death minus 5 years for all individuals over the age of 34. the data were assembled in genome studio (illumina, san diego, ca). those snps in chr 1 to 22 that failed the call frequency parameter (defined as 0.3). samples with call rates 0.125), and snps were checked for minor allele frequency (0.01), haplotype missingness (p < 10e-4), and hardy weinburg equilibrium (p < 10e-6). ten samples were excluded (6 were duplicates of another sample in the study). 58,737 snps were excluded at this stage, of which 58,405 were due to maf < 0.01. the outcome of this process resulted in 139 samples (61 female and 78 male) and 642,251 snps for further analysis. those samples that were 4 standard deviations away from the mean of ceu / tsi combined data were excluded. ten samples were found to be nonwhite or mixed. at this stage, only 129 samples (72 male and 57 female) and 642,251 snps remained. as dementia develops at a mean age of 50 to 55 years, and in our clinical sample series, the earliest age of dementia onset was 34 years, we excluded all cases with age < 34 at their last cognitive assessment or autopsy. this resulted in 120 valid samples with 70 having dementia (clinically defined, or belonging to the autopsy cohort). among the 70 dementia cases, 3 had no aao in the record. the youngest age in the autopsy series was 39, and therefore aao in this case was 34 as defined above. there were no differences in gender frequencies between the clinical and autopsy samples used at this stage (= 0.005, p = 0.946) or age (mann whitney u test, p = 0.419). the meadows trial showed that memantine was not an effective treatment for cognitive decline in ds (hanney. there were no aao differences between those taking placebo and memantine in the 17 samples used for the aao analysis (t = 0.621, p = 0.545). no individuals from the downslit trial developed dementia, and so were excluded from this further analysis. analysis was carried out in plink using a linear regression with aao and the snps in an additive model. the snps were selected from previous gwas meta - analyses (hollingworth., 2011 ; naj., 2011) and had reached statistical significance or possible significance (supplementary table 8 (hollingworth., 2011), tables 1 and 2, and supplementary table 5 (naj., 2011)). of the 531 snps found in these 2 papers, only 157 snps were also successfully genotyped by humanomniexpress-12v1_h in this study (most were absent in this array). component 1 and component 2 in plink multidimensional scaling were used as covariates, in addition to gender and the classification of the sample as clinical or autopsy. a nominal p value of 0.05 was used as a cut - off for further analysis. we generated a composite score of ad risk allele loading based on the snps reported by bettens. we correlated the age of onset in our ds cases with the composite score derived from ad studies. in addition, we compared aao between the quintiles with highest and lowest score. for details we found a significant association between aao and variation at the chromosome 11 picalm region. three snps, rs2888903 (= 3.31, p = 0.011), rs7941541 (= 3.92, p = 0.016), and rs10751134 (= 2.78, p = 0.040) were associated (fig. all of these picalm snps show a decreased aao in individuals who are homozygous for the major allele. there is also a significant association between aao and apoe, replicating associations found with ad risk in previous studies. the median aao in patients homozygous for the minor allele in rs405509, a snp linked with apoe, was 5 years older than those homozygous for the major allele (= 3.58, p = 0.014), (fig. two snps in tomm40, which is immediately 5 to apoe, were also associated with aao ; rs2075650 (= 3.4, p = 0.036, fig. 1e) and rs8106922 (= 3.32, p = 0.031, fig. these picalm, apoe and tomm40 snps show the same direction of effect as in studies in the general population : that is, an increased risk of ad in the general population equates with an earlier aao in the ds population in this study. the only snp in our study that showed a significant effect in the direction opposite to that found in the general population was rs3865444 in cd33 ; but it is not protective, as was found in the ad gwas studies (table s3). the other genes previously found to have been associated with ad risk did not have significant associations with aao of ad (table s3). with regard to risk score analysis, when comparing the upper and lower quintiles, aao changed from 48.1 (sd 6.3) to 52.9 (sd 6.9) (table s4) (mann whitney u test, p = 0.084). there is a trend toward an association between aao and allele composite score (p = 0.166) (figure s1). for every increase of 1 in the composite score, aao decreased by 0.67 year. the major alleles of the 3 snps in picalm, rs2888903, rs7941541, and rs10751134, are associated with an increased risk of ad in the general population and an earlier aao in the ds population. a further snp in picalm, rs561655, whose association with ad was the most significant in the study by naj. (2011) was not significantly associated with aao of ad in our cohort (data not shown), but had the same protective result as that found by naj. the 3 picalm snps noted in this study are in linkage disequilibrium (ld). a further picalm snp that has been associated with ad in the general population, rs3851179, is in ld with both rs7941541 and rs10751134. as with rs561655, we do not find this snp to be significantly associated in our study, but its effect is protective, as found in the general population. similarly, the results for the apoe snp rs405509 and tomm40 snp rs8106922 are in accordance with the study by naj. (2011), with the minor allele having a protective effect upon the onset of dementia. the minor allele of rs2075650 in tomm40 is associated with increased risk of ad (naj., 2011) and an earlier aao in our current study, although this is most likely due to ld with the apoe locus. with regard to the composite risk score analysis, the level of significance is likely limited by our sample size ; but this analysis has shown that using a composite score may help in predicting the risk and should be one of the directions in future studies. the score is likely dominated by apoe, given that the other snps have a much lower or in the ad meta - analyses. this gwas was powered to detect only the risk associated with apoe, and is too underpowered to detect the many more subtle changes associated with ad risk in the general population. although apoe has previously been associated with the risk of developing ad in individuals with ds, picalm has not. even with a small sample size, we are examining a population with a more homogeneous ad risk than that of the general population, and by using the results of previous gwas to focus our study, we can detect genetic risk factors that have not yet been associated with ds. any differences between our results and those of ad gwas meta - analyses (e.g., hollingworth., 2011 ; naj., 2011) are most likely due to the much lower number of samples used in our study. because of this small sample size, we have not currently applied a multiple testing correction to our data, which we acknowledge to be a limitation of this study. ad in ds is still a relatively understudied area in the field of neurodegeneration, and this study highlights the need for larger collaborative studies that would improve our chances of dissecting the key genetic pathways which accelerate the onset of dementia. as studies in this field continue, we can identify further similar genetic risk factors between ad in the general population and ds. given the high occurrence of ad in people with ds, we have the opportunity to examine factors that affect aao and disease progression, but only when large international collaborations are in place will we be able to fully take advantage of this opportunity. for this reason, we have made all of the genome - wide data available as plink files (data s1), which we hope other researchers in this area will make use of in meta - analysis studies. julie williams has research collaborations with elly - lilly and population genetics technologies ltd (cambridge) and has presented papers at conferences funded by esai. | it is known that individuals with down syndrome develop alzheimer s disease with an early age at onset, although associated genetic risk factors have not been widely studied. we tested whether genes that increase the risk of late - s disease influence the age at onset in down syndrome using genome - wide association data for age at onset of dementia in a small sample of individuals (n = 67) with down syndrome. we tested for association with loci previously associated with alzheimer s disease risk and, despite the small size of the study, we detected associations with age at onset of alzheimer s disease in down syndrome with picalm (= 3.31, p = 0.011) and the apoe loci (= 3.58, p = 0.014). as dementia in people with down syndrome is relatively understudied, we make all of these data publicly available to encourage further analyses of the problem of alzheimer s disease in down syndrome. |
in october 2007, a 28-year - old man (student) sought care for a rash of 6 months duration and generalized joint pains of a few days duration. he reported being well until 6 months earlier, when he noticed a rash on his left leg. it began as a lesion on his thigh and spread throughout his entire left lower limb and upper limbs. the patient s joints showed no signs of inflammation. on his left outer thigh was a large lesion (8 cm 5 cm) with many similar lesions 15 cm in diameter, with central clearing on the rest of his lower limb and upper limb (figure 1). two visits to a dermatologist resulted in prescriptions for topical ketoconazole and beclomethasone, which had no effect on the rash. erythema migrans like rash on the left leg of a 28-year - old patient. a) characteristic rash of erythema migrans (annular macular lesion that is erythematous with central clearing). in 2005, he had spent 2 weeks in new york, new york, usa. he did not recall being bitten by ticks in either place. because of the rash and the exposure to ticks, a tick - borne illness was considered. serologic analysis for b. burgdorferi and histologic analysis of a skin biopsy specimen were undertaken, and the patient was treated with doxycycline, 100 mg 2/d for 2 weeks. within 1 week, his arthralgia disappeared, and by week 2, the rash had resolved. at 6-month follow - up, the rash had not recurred. results for immunoglobulin (ig) m and igg to b. burgdorferi by enzyme immunoassay and the c6 peptide antibody were negative. histologic analysis of the skin biopsy specimen showed perivascular lymphocytic infiltrates with admixture of plasmocytes, consistent with em (figure 2). on the basis of the clinical findings and negative serologic results for b. burgdorferi, an em - like illness was diagnosed. histologic analysis of a skin biopsy specimen of a 28-year - old patient with erythema migrans, showing characteristics of erythema migrans. the epidermis shows parakeratosis, microvesicle formation, lichenoid interface, dermal edema, and perivascular chronic inflammatory cell infiltrates. original magnification 20 (a) and 40 (b). in march 2008, a 15-year - old boy from trinidad and tobago sought care for a red pruritic rash of 4 weeks duration. atopic eczema was again diagnosed and topical steroid cream prescribed, but the rash persisted. on examination in april 2008, a 60-year - old woman from grenada with diabetes sought care for an ongoing pruritic rash of 46 months duration. the rash had an erythematous, flat border with a central clearing 7 cm in diameter but no punctum. visits to several doctors resulted in prescriptions for vitamin a, vitamin e, and steroid and antifungal creams, all of which partially cleared the rash. after treatment with doxycycline for 7 days, the rash resolved and had not recurred after 1 year. in january 2010, a 48-year - old woman (veterinary laboratory assistant) from trinidad and tobago sought care for a circular, erythematic rash of 2 weeks duration. the rash started on her right leg ; had a flat, erythematous border with central clearing ; and progressively increased to 5.1 cm in diameter. two similar 23-cm lesions on her left leg appeared 3 days after the first lesion. she also reported fatigue, mild body and joint pains, and headaches relieved by acetaminophen. the rash began clearing after 2 weeks of treatment and had not recurred after 4 months. summer seasonality, recent antecedent tick bite at the site of the skin rash, absence of b. burgdorferi antibodies, and negative skin biopsy culture results for b. burgdorferi (2). because none of our patients recalled an antecedent tick bite or had a punctum, their illnesses failed to meet the criteria for stari. in a prospective clinical evaluation of em, lesions in stari patients from missouri were substantially smaller and more likely to have central clearing, and patients had a lower mean symptom score, compared with ld patients in a new york study (3). although clinical findings of our patients were comparable with those of the missouri stari patients, our patients multiple, widespread, and oblong lesions with no punctum and lack of known histories of tick bite were comparable with those of new york ld patients (3). ticks are the vector, stari is thought to be spread by the lone star tick (ambylomma americanum), the most common tick parasitizing humans in the southeastern and south - central united states (4). it is not an effective carrier of b. burgdorferi ; however, 2% of the species are infected with another spirochete, b. lonestari (5). in 1 isolated case, b. lonestari was identified by pcr as the etiologic agent of stari (6). in another report, no evidence of b. lonestari infection was found in 30 cases studied (7). em also has been associated with other infectious agents. in an imported human african trpanosomiasis case in france (9), dermacentor marginatus ticks infected with rickettsia slovaca produced em - like rash and lymphadenopathy in 22 patients studied. in addition, em has been reported as a skin manifestation in rocky mountain spotted fever (10). a. americanum ticks occur mainly in north america and certain areas of mexico (11). a. americanum ticks and the ld vectors (i. scapularis and i. pacificus ticks) are not found in the caribbean (11). the vector for the em - like rash in our cases is therefore unlikely to be that of either stari or ld. whether these species are potential vectors for em remains unknown ; therefore, whether we are describing a new entity, caribbean erythema migrans like illness, remains to be determined. we report em - like skin lesions in 4 caribbean nationals who did not have foreign exposure to ticks. the vectors for stari and ld are not known to exist in the caribbean region. | erythema migrans is the skin manifestation of lyme disease and southern tick - associated rash illness. neither disease is found in the caribbean. we report 4 cases of erythema migrans of a possible emerging clinical entity, caribbean erythma migrans like illness. |
this group is known to suffer from greater burden and more rapid progression of coronary atherosclerosis compared to non - diabetic patents. this is the effect of several cardiovascular risk factors associated with diabetes mellitus (dm), which make percutaneous coronary interventions (pci) more challenging and aggravate the risk for adverse outcome [13 ]. accordingly, for patients with dm and multivessel and/or complex cad, coronary artery bypass grafting (cabg) has better performance, and pci is a valuable alternative in less complex cases. the marked improvement in the efficacy and safety of pci seen in numerous randomized trials was the response to advances in stent technology from bare metal stents (bms) to early drug - eluting stents (des) in the general population as well as in diabetics [610 ]. adverse outcomes after coronary revascularization in patients with dm remain, however, a concern regarding which type of des to use. this study aimed at comparing long - term safety and efficacy after pci with first- and second - generation des in an unrestricted, real - life, 2-center population of diabetic patients. the katowice - zabrze registry is an investigator - initiated all - comer registry of consecutive patients treated with pci with implantation of des. the registry was designed to evaluate the differences in outcome between first- and second - generation des in an unrestricted population, reflecting real clinical conditions. the enrollment was conducted in 2 tertiary high - volume (together 5500 pci / year) cardiac centers (upper silesian medical center in katowice and 2 department of cardiology, zabrze) from 1 january 2009 to 31 december 2010. the registry retrospectively included all patients in medical records of enrolling centers who had undergone pci with the implantation of either first- or second - generation des. the subject for current sub - analysis of the registry was the sub - group of patients with dm, using the same inclusion criteria as for the main registry. basic angiographic characteristics were recorded from the medical records of coronary angiography : location of the lesion, severity of stenosis, the american college of cardiology / american heart association (acc / aha) lesion type, thrombus, and calcifications. aha / acc classification is a system used for assessment of lesion morphology (length, radial distribution, angulation, accessibility, contour, calcifications, location, branch involvement, and thrombus) and provides information on the probability of procedure success or failure. in every patient, excluding patients after cabg, the severity of coronary artery disease was assessed with the syntax score, a validated tool used for scoring of coronary artery disease complexity. it reflects coronary anatomy, location of the lesion, degree of stenosis, collaterals, length, calcifications, thrombotic component, number of lesions, and number of segments involved. stents were chosen according to the operator s decision according to current best practice, the best knowledge, and individual experience and preferences regarding particular stent characteristics suitable to lesion type found on coronary angiogram. stent types were made of first - generation durable polymer - based des [paclitaxel - eluting stents (taxus, boston scientific corporation, maple grove, mn, usa ; lucchopin1, lucchopin2, balton, poland) or sirolimus - eluting stents (cypher, cordis, usa ; carlo, carlos, balton, poland) ] or second - generation des [everolimus - eluting stents (promus, boston scientific corporation ; xience, xience prime, abbott vascular, santa clara, ca, usa), zotarolimus - eluting stents (endeavor, resolute, medtronic, minneapolis, mn, usa), and biolimus - eluting stent (biolimus a9, biosensors international, switzerland) ]. in case of implantation of more than 1 stent in 1 patient, the des implanted to the lesion or to more severe stenosis was considered as the index procedure. when patients received both first- and second - generation stents, they were considered to have received an older - generation des. dual antiplatelet therapy (acetylsalicylic acid and p2y12 subtype of adp receptor inhibitors) was prescribed for up to 12 months after the procedure in each patient. baseline clinical, angiographic, and procedure - related data were retrospectively collected from medical records. if no information was available, phone contact was attempted. in case of phone contact failure, the primary efficacy endpoint was a composite of major adverse cardiac and cerebrovascular events (macce), including all - cause death, non - fatal myocardial infarction (mi), target vessel revascularization (tvr), and stroke. the secondary endpoints were individual components of the primary endpoint : all - cause death, mi, tvr, stroke, and coronary artery bypass grafting (cabg). the safety of des was defined as definite st (acute, subacute, late, and cumulative) and gastrointestinal bleeding rates at 1 year. all endpoints for the sub - analyzed group described above were consistent with endpoints for the main registry. tvr, definite st, acute, subacute, and late st were defined according to the definitions of endpoints for clinical trials. gastrointestinal bleeding was considered an endpoint if it fulfilled criteria for type 3 or type 5 bleeding according to proposed definitions. continuous variables are presented as mean sd or median (25 ; 75 percentile) and were compared with t test or mann - whitney test. the kaplan - meier method was used to present estimated incidence of endpoints and the long - rank test was used to assess differences between groups. clinical, hemodynamic, and procedural characteristics that differed significantly between groups were used for univariate cox regression for assessing the influence on clinical endpoints. multivariate cox regression model for primary and secondary endpoints and st included all variables statistically significant in univariate analysis. tulsa, ok, usa) and graphpad prism software version 6.00 (graphpad, la jolla, california, usa). the katowice - zabrze registry is an investigator - initiated all - comer registry of consecutive patients treated with pci with implantation of des. the registry was designed to evaluate the differences in outcome between first- and second - generation des in an unrestricted population, reflecting real clinical conditions. the enrollment was conducted in 2 tertiary high - volume (together 5500 pci / year) cardiac centers (upper silesian medical center in katowice and 2 department of cardiology, zabrze) from 1 january 2009 to 31 december 2010. the registry retrospectively included all patients in medical records of enrolling centers who had undergone pci with the implantation of either first- or second - generation des. the subject for current sub - analysis of the registry was the sub - group of patients with dm, using the same inclusion criteria as for the main registry. basic angiographic characteristics were recorded from the medical records of coronary angiography : location of the lesion, severity of stenosis, the american college of cardiology / american heart association (acc / aha) lesion type, thrombus, and calcifications. aha / acc classification is a system used for assessment of lesion morphology (length, radial distribution, angulation, accessibility, contour, calcifications, location, branch involvement, and thrombus) and provides information on the probability of procedure success or failure. in every patient, excluding patients after cabg, the severity of coronary artery disease was assessed with the syntax score, a validated tool used for scoring of coronary artery disease complexity. it reflects coronary anatomy, location of the lesion, degree of stenosis, collaterals, length, calcifications, thrombotic component, number of lesions, and number of segments involved. stents were chosen according to the operator s decision according to current best practice, the best knowledge, and individual experience and preferences regarding particular stent characteristics suitable to lesion type found on coronary angiogram. stent types were made of first - generation durable polymer - based des [paclitaxel - eluting stents (taxus, boston scientific corporation, maple grove, mn, usa ; lucchopin1, lucchopin2, balton, poland) or sirolimus - eluting stents (cypher, cordis, usa ; carlo, carlos, balton, poland) ] or second - generation des [everolimus - eluting stents (promus, boston scientific corporation ; xience, xience prime, abbott vascular, santa clara, ca, usa), zotarolimus - eluting stents (endeavor, resolute, medtronic, minneapolis, mn, usa), and biolimus - eluting stent (biolimus a9, biosensors international, switzerland) ]. in case of implantation of more than 1 stent in 1 patient, the des implanted to the lesion or to more severe stenosis was considered as the index procedure. when patients received both first- and second - generation stents, they were considered to have received an older - generation des. dual antiplatelet therapy (acetylsalicylic acid and p2y12 subtype of adp receptor inhibitors) was prescribed for up to 12 months after the procedure in each patient. baseline clinical, angiographic, and procedure - related data were retrospectively collected from medical records. patients were followed - up at 1 year. all information was obtained from medical records of enrolling centers. if no information was available, phone contact was attempted. in case of phone contact failure, the primary efficacy endpoint was a composite of major adverse cardiac and cerebrovascular events (macce), including all - cause death, non - fatal myocardial infarction (mi), target vessel revascularization (tvr), and stroke. the secondary endpoints were individual components of the primary endpoint : all - cause death, mi, tvr, stroke, and coronary artery bypass grafting (cabg). the safety of des was defined as definite st (acute, subacute, late, and cumulative) and gastrointestinal bleeding rates at 1 year. all endpoints for the sub - analyzed group described above were consistent with endpoints for the main registry. tvr, definite st, acute, subacute, and late st were defined according to the definitions of endpoints for clinical trials. gastrointestinal bleeding was considered an endpoint if it fulfilled criteria for type 3 or type 5 bleeding according to proposed definitions. continuous variables are presented as mean sd or median (25 ; 75 percentile) and were compared with t test or mann - whitney test. the kaplan - meier method was used to present estimated incidence of endpoints and the long - rank test was used to assess differences between groups. clinical, hemodynamic, and procedural characteristics that differed significantly between groups were used for univariate cox regression for assessing the influence on clinical endpoints. multivariate cox regression model for primary and secondary endpoints and st included all variables statistically significant in univariate analysis. tulsa, ok, usa) and graphpad prism software version 6.00 (graphpad, la jolla, california, usa). 717 (37%) patients had diabetes, in which the present analysis was conducted. within this group, 257 patients (36%) were treated with first - generation des (of them 230 [89% ] paclitaxel - eluting stents, 27 [11% ] sirolimus - eluting stents) and 460 (64%) with second - generation des (of them 46 [10% ] biolimus - eluting stents, 243 [53% ] everolimus - eluting stents, 171 [37% ] zotarolimus - eluting stents). both groups had comparable baseline demographic profiles, prior revascularization, and cardiovascular risk factors (table 1). patients who received second - generation des had higher ef (54 [45;60 ] vs. 50 [40;55]%, p=0.004), and more often suffered from renal insufficiency (26% vs. 19%, p=0.03) in comparison to patients with first - generation des. patients did not differ regarding treated vessel and cad burden as measured with syntax score (with median score of 15 points in both groups, p=0.4). first - generation des were implanted to more calcified lesions with lower maximal inflation pressure and were less frequently evaluated with ivus (table 2). procedures did not differ regarding length and diameter of the stent or total number of stents per lesion. regarding clinical setting, both stent generations were implanted in equal proportions in acs (67% for first- vs. 72% for second - generation des, p=0.13), with second - generation predominance in ua (p=0.001) and first - generation in patients with stemi (p=0.02) (table 1). angiographic outcome of the procedure was equal for first- and second - generation des and final timi 3 flow was achieved in 98% and 97% of cases, respectively (p=0.41). procedures with first- and second - generation des were equally efficient, with no significant difference in the incidence of the primary and secondary endpoint at 1 year (table 3). the kaplan - meier curves, presented in figure 1, show the incidence of macce. in univariate cox regression model, significant factors for prediction of macce were renal insufficiency (hr 1.82 [1.232.7 ], p=0.003), ejection fraction (hr 0.97 [0.960.98 ], p<0.001), maximal concentration of troponin (1.1 [1.041.18 ], p=0.001) and ck - mb (hr 1.003 [1.0011.01 ], p=0.002), and the diagnosis of stemi (hr 2.0 [1.123.56 ], p=0.02). after adjustment, only renal insufficiency (hr 1.69 [1.132.52 ], p=0.01) and ejection fraction (hr 0.98 [0.960.99 ] p=0.003) remained statistically significant predictors of macce (table 4). regarding the incidence of death, significant predictors in univariate analysis were renal insufficiency (hr 4.07 [2.097.91 ], p<0.001), ejection fraction (hr 0.92 [0.90.95 ], p<0.001), nyha (hr 1.89 [1.282.8 ], p=0.001), maximal concentration of troponin (hr 1.16 [1.091.24 ], p<0.001) and ck - mb (hr 1.005 [1.0031.008 ], p<0.001), and the diagnosis of stemi (hr 3.66 [1.68.39 ], p=0.002). after adjustment, in the multivariate model, factors statistically significant for the prediction of death were renal insufficiency (hr 3.32 [1.656.68 ], p<0.001) and ejection fraction (hr 0.93 [0.910.96 ], p<0.001) (table 4). the safety profile in acute and subacute setting was better after implantation of second - generation des when compared to first - generation des (0.2% vs. 1.9%, p=0.02 for acute and 0% vs. 1.2%, p=0.02 for subacute st). this advantage was not further observed in 1-year follow - up, with no statistically significant difference in late st (0.2% vs. 0.8%, p=0.27) (figure 2). the incidence of st over time is presented with kaplan - meier curves (figure 1d). there was an early and continuous separation of curves in favor of second - generation des. the generation of des was an independent risk factor in cox regression model for cumulative st at 1 year (hr 9.07 [1.9941.39 ], p=0.004). other factors predictive for cumulative st were the diagnosis of stemi (hr 7.04 [2.1223.39 ], p=0.001), ejection fraction (hr 0.95 [0.910.99 ], p=0.03), de novo lesion (hr 0.99 [0.970.998 ], p=0.02), and maximal inflation pressure (hr 0.79 [0.650.95 ], p=0.01). in multivariate cox analysis, the generation of des remained a predictive factor for cumulative st (hr 5.75 [1.1628.47 ], p=0.03) together with the diagnosis of stemi (hr 4.38 [1.2115.9 ], p=0.02) (table 4). the rates of gastrointestinal bleeding were low and did not differ between groups (p=0.5) (table 3). procedures with first- and second - generation des were equally efficient, with no significant difference in the incidence of the primary and secondary endpoint at 1 year (table 3). the kaplan - meier curves, presented in figure 1, show the incidence of macce. in univariate cox regression model, significant factors for prediction of macce were renal insufficiency (hr 1.82 [1.232.7 ], p=0.003), ejection fraction (hr 0.97 [0.960.98 ], p<0.001), maximal concentration of troponin (1.1 [1.041.18 ], p=0.001) and ck - mb (hr 1.003 [1.0011.01 ], p=0.002), and the diagnosis of stemi (hr 2.0 [1.123.56 ], p=0.02). after adjustment, only renal insufficiency (hr 1.69 [1.132.52 ], p=0.01) and ejection fraction (hr 0.98 [0.960.99 ] p=0.003) remained statistically significant predictors of macce (table 4). regarding the incidence of death, significant predictors in univariate analysis were renal insufficiency (hr 4.07 [2.097.91 ], p<0.001), ejection fraction (hr 0.92 [0.90.95 ], p<0.001), nyha (hr 1.89 [1.282.8 ], p=0.001), maximal concentration of troponin (hr 1.16 [1.091.24 ], p<0.001) and ck - mb (hr 1.005 [1.0031.008 ], p<0.001), and the diagnosis of stemi (hr 3.66 [1.68.39 ], p=0.002). after adjustment, in the multivariate model, factors statistically significant for the prediction of death were renal insufficiency (hr 3.32 [1.656.68 ], p<0.001) and ejection fraction (hr 0.93 [0.910.96 ], p<0.001) (table 4). the safety profile in acute and subacute setting was better after implantation of second - generation des when compared to first - generation des (0.2% vs. 1.9%, p=0.02 for acute and 0% vs. 1.2%, p=0.02 for subacute st). this advantage was not further observed in 1-year follow - up, with no statistically significant difference in late st (0.2% vs. 0.8%, p=0.27) (figure 2). the incidence of st over time is presented with kaplan - meier curves (figure 1d). there was an early and continuous separation of curves in favor of second - generation des. the generation of des was an independent risk factor in cox regression model for cumulative st at 1 year (hr 9.07 [1.9941.39 ], p=0.004). other factors predictive for cumulative st were the diagnosis of stemi (hr 7.04 [2.1223.39 ], p=0.001), ejection fraction (hr 0.95 [0.910.99 ], p=0.03), de novo lesion (hr 0.99 [0.970.998 ], p=0.02), and maximal inflation pressure (hr 0.79 [0.650.95 ], p=0.01). in multivariate cox analysis, the generation of des remained a predictive factor for cumulative st (hr 5.75 [1.1628.47 ], p=0.03) together with the diagnosis of stemi (hr 4.38 [1.2115.9 ], p=0.02) (table 4). the rates of gastrointestinal bleeding were low and did not differ between groups (p=0.5) (table 3). based on the subanalysis of diabetic patients from the katowice - zabrze registry in a real - life setting, the implantation of second - generation des proved to be equally efficient and to have better safety profile when compared to first - generation des. the trend for lower rates of st in second - generation des was most pronounced early after stent placement and was sustained for up to 1 year. diabetes mellitus is known to enhance the risk of st and restenosis after pci, already elevated by eosinophilia, by promoting neointimal hyperplasia, smooth muscle cell proliferation, increased platelet reactivity, local inflammatory process, and plaque growth. despite better in - stent performance of second- (everolimus - eluting) than first - generation (sirolimus-, paclitaxel - eluting) des with lower in - stent late lumen loss for everolimus - eluting stents described in the literature [1720 ], we observed equal combined event rates regardless of the type of eluting drug. indeed, second - generation des were safer than first - generation des and significantly reduced the rate of st. thus, our results confirm superiority of second- vs. first - generation des in patients with dm in terms of st, first reported by simsek. it is also known that the presence of dm worsens the prognosis, aggravating the 10-year risk of adverse events in patients with cad to 75%. we report a relatively high rate of macce when compared with previous reports from rcts on patients with dm. first, it could reflect the high percentage of acute coronary syndrome in the population. this fact could be regarded as confirmation of the thesis that dm is a strong risk factor for adverse events, regardless of lesion complexity. however, the performance of different types of des in this setting is unknown. regarding this, the fact of equal incidence of overall macce in diabetic patients, regardless of the type of stent, seems interesting. a previous report suggested that the role of secondary prevention is more important than the choice of a particular des. we observed no differences in rates of individual components of macce (including ami and tvr), contrary to what was reported previously in large rcts [9,2931 ], but confirmed, on the other hand, in a pooled analysis of spirit ii, spirit iii, spirit iv, and compare studies. this observation is of great value, as most of the available data came from rcts conducted in well - developed, western - european countries and our registry is the first analysis in this field from central / eastern europe on such a large population. it shows comparable outcomes, thus strengthening the recommendation for the use of second - generation des. moreover, to date, there have been few studies evaluating the use of first- vs. second - generation des in diabetic patients in real - life, all - comer settings. our study is comparable to only 1 registry, which concluded there was no difference between first- and second - generation des in diabetics. our study adds information showing the better safety of pci with second - generation des in an unrestricted population of diabetics, reflecting circumstances met in everyday clinical practice, with the potential for direct implementation of the outcomes in real life. in studies (mostly rcts) on diabetic patients that account for baseline characteristics to improve the precision of risk estimates, the reduction in st rate with similar mace rate shows the advantage of use of second - generation des. in light of this fact, the advantage of this real - life registry is the similarity in baseline profile between both groups, although not matched in - pair. this enables relatively thorough comparison of outcomes from previous studies, which are in line with those presented in our study. the present study adds to the available data on safety and efficacy of different types of des for pci in diabetic patients, leading to the conclusion that the performance of second - generation des in real - life setting of dm is advantageous in terms of safety of the procedure, especially early after stent placement. based on this, patients with dm after implantation of first - generation of des should undergo restrictive follow - up, especially early after the procedure, focused on signs and symptoms suggestive of st. the implantation of second - generation of des should be considered in every case of pci in diabetic patients in order to reduce the rate of st. assuming that insulin - dependent dm provokes more attenuated general and in situ negative effects and plaque burden in vessels by the mechanism evolved by insulin resistance, the division in insulin - dependent and non - insulin - dependent dm patients could enrich the study and provide additional guidance on optimal choice between first- and second - generation des for pci in each group ; however, this was not done because we did not want to lower the size of compared groups with low number of end - points (st) in the population. assuming that insulin - dependent dm provokes more attenuated general and in situ negative effects and plaque burden in vessels by the mechanism evolved by insulin resistance, the division in insulin - dependent and non - insulin - dependent dm patients could enrich the study and provide additional guidance on optimal choice between first- and second - generation des for pci in each group ; however, this was not done because we did not want to lower the size of compared groups with low number of end - points (st) in the population. | backgroundthis study compared safety and efficacy of first- and second - generation des in an unrestricted, real - life population of diabetic patients undergoing pci.material/methodsthe study was a subanalysis of diabetic patients from the all - comer katowice - zabrze registry of patients undergoing pci with the implantation of either first- (paclitaxel-, sirolimus - eluting stents) or second - generation des (zotarolimus-, everolimus-, biolimus - eluting stents). efficacy defined as major adverse cardiac and cerebrovascular events (macce : death, myocardial infarction, target vessel revascularization, stroke) and safety defined as stent thrombosis (st) were evaluated at 1 year.resultsfrom the total of 1916 patients, 717 were diabetics. among them, 257 (36%) were treated with first - generation des (230 [89% ] paclitaxel - eluting stents, 27 [11% ] sirolimus - eluting stents), 460 with second - generation des (171 [37% ] zotarolimus - eluting stents, 243 [53% ] everolimus - eluting stents, 46 [10% ] biolimus - eluting stents). rate of macce was equal in both groups (p=0.54). second - generation des had a better safety profile than first - generation des (log - rank for cumulative st at 1 year p<0.001). first - generation des was a risk factor for st (hr 5.75 [1.1628.47 ], p=0.03) but not for macce (hr 0.89 [0.61.32 ], p=0.57).conclusionsin a real - life setting of diabetic patients undergoing pci, second - generation des had lower risk of st and similar macce rate compared to first - generation des. |
patients with peripheral arterial disease (pad) have significantly increased rates of myocardial infarction (mi), cardiovascular mortality, and stroke.1 cross - sectional studies have shown that approximately half of all patients with pad have some clinical evidence of coronary artery disease or cerebrovascular disease.2,3 the risk of mortality and major cardiovascular events (eg, heart attack and stroke) is approximately threefold higher in pad patients than in those without pad.46 with an aging population and improved quality of medical care, physicians face an ever - increasing number of elderly patients presenting with progressed forms of pad.7,8 advanced age is associated with increased perioperative and postoperative mortality after vascular operations because of multiple comorbidities.912 untreated chronic critical limb ischemia (cli), an advanced stage of pad, is associated with a dismal prognosis.1,13 on the contrary, cli patients with successful revascularization have a better quality of life and longer survival when compared to those treated conservatively or with primary amputation.5,14 the wide use of endovascular therapy (evt) and evidence of better short - term survival compared with bypass surgery9,10,15 render angioplasty a tempting first - choice treatment in very elderly vascular patients. there are no specific guidelines for the treatment of elderly patients with pad, and information regarding long - term vascular events following evt in elderly versus younger patients is scarce in asian countries. in this study, we performed a retrospective review using a prospective registry of all patients undergoing evt at our institution over a 10-year period. the immediate results, functional improvement, and long - term cardiovascular outcomes were analyzed to determine the safety and effectiveness of evt between groups. subjects for this study were derived from the tzuchi registry of endovascular intervention for peripheral artery disease (trendpad), which is an ongoing, prospective, physician - initiated, single - center observational registry of patients who underwent evt for lower limb ischemia starting from july 2005. this database was interrogated to identify adult patients with symptomatic pad treated between july 2005 and december 2013. to be eligible for this analysis, patients were required to have an age 18 years, provide written consent to participate in this study, and a candidate for evt originating from atherosclerotic pad. patients who had acute limb ischemia, nonatherosclerotic pad, a life - threatening infection, follow - up duration 140 mmhg or diastolic pressure > 90 mmhg), diabetes mellitus (use of oral hypoglycemic agent or insulin, fasting plasma sugar 126 mg / dl, or glycated hemoglobin level 6.5%), atrial fibrillation (af), congestive heart failure (chf) (ejection fraction 50% in at least one of the three main coronary arteries), stroke, and dialysis dependence ; and history of smoking (defined as smoking within the previous year). serum c - reactive protein (crp) values, determined by high - sensitivity assay, were obtained before evt or at admission. normolipidemia was defined as total cholesterol 140 mmhg or diastolic pressure > 90 mmhg), diabetes mellitus (use of oral hypoglycemic agent or insulin, fasting plasma sugar 126 mg / dl, or glycated hemoglobin level 6.5%), atrial fibrillation (af), congestive heart failure (chf) (ejection fraction 50% in at least one of the three main coronary arteries), stroke, and dialysis dependence ; and history of smoking (defined as smoking within the previous year). serum c - reactive protein (crp) values, determined by high - sensitivity assay, were obtained before evt or at admission. normolipidemia was defined as total cholesterol < 200 mg / dl or low - density lipoprotein (ldl) cholesterol < 100 mg / dl without the use of statin treatment, and baseline serum ldl cholesterol levels were determined using the most recent value within 3 months preprocedure. a single - level intervention was defined as evt for isolated aortoiliac, femoropopliteal, or below - the - knee lesions. functional status was classified as ambulatory independently, ambulatory with assistive device, wheelchair - bound, and bed - ridden status. the changes in functional status at presentation and 6 months after evt were compared between groups. nonfatal cardiovascular events included nonfatal mi, stroke, or transient ischemic attack ; hospitalization with decompensated heart failure ; percutaneous coronary intervention or coronary artery bypass surgery ; and hospitalization with angina pectoris or ischemic hands. vascular death included fatal stroke, or sudden death due to mi, chf, af, nonrheumatic heart valve disease, and ruptured aortic aneurysm. the safety end point was 30-day major adverse vascular events (maves) (death, mi, stroke, emergent surgery, contrast - induced acute kidney injury requiring dialysis, subacute arterial occlusion, groin complications requiring manual compression or surgical repair, and unplanned reintervention), while efficacy was based on procedure success (successful access and deployment of the device and 30% residual stenosis by quantitative angiography with evidence of at least one patent tibial artery to the foot). outcomes in follow - up included major cerebrovascular and cardiovascular events (macces) (any death and nonfatal cardiovascular events) and composite vascular events (cves) (vascular deaths, nonfatal cardiovascular events, and major amputation). clinical improvement was defined as a 2 rutherford category improvement, an increase in ankle brachial index (abi) of at least 0.15, and wound healing in 4 months after the index intervention for patients with tissue loss. sustained clinical success (scs) was defined as clinical improvement without target vessel revascularization or major amputation (limb loss above the ankle). at 1 week, 1 month, and thereafter every 3 months after evt, each patient was assessed by symptoms, ankle or toe brachial pressure index, and duplex ultrasounds. repeat interventions were performed if recurrent symptoms, significant vessel stenosis (70%) with dampened doppler waveform patterns by duplex ultrasound, and an abi decrease of 0.15 were observed. the main events (death, amputation, failure of scs, and late vascular events) were documented at discharge and at follow - up visits. if office follow - up visits were not feasible, alternate data sources included telephone interviews, medical records, the local electronic medical database, and the referring physician. all continuous data were expressed as mean standard deviation and were analyzed using independent t - tests. a frequency comparison was performed using the chi - square test or fisher s exact tests. variables with p<0.2 in the univariate analyses were backward selected into the multivariate analysis. independent sample t - test was used to compare the functional changes after evt between groups. survival curves, macce, and cve were plotted using the kaplan meier method and analyzed using the log - rank test (sas software version 9.2 ; sas institute inc., cary, nc, usa). a two - tailed p - value of < 0.05 was considered significant. during the study period, 573 patients with 728 affected legs were treated with evt. of them, ten patients were excluded (seven with acute limb ischemia and three with vasculitis - related pad). the remaining 563 patients were divided into two groups based on age (80 years or < 80 years). fifty - two patients (64 legs) were not entered into the analysis of long - term outcomes : 34 patients (40 legs) with failed procedures and 18 patients (24 legs) with a follow - up time < 30 days or in - hospital mortality. the final cohort for long - term outcome analysis included 136 patients (170 legs) in octogenarians and 375 patients (484 legs) in nonoctogenarians. octogenarians were more likely to be female and have higher incidence of af, whereas nonoctogenarians were more likely to have diabetes mellitus, dialysis dependence, history of smoking, hyperlipidemia, and a high body mass index (bmi). the hematocrit, neutrophil - to - lymphocyte ratio, platelet - to - lymphocyte ratio, and levels of serum albumin and ldl cholesterol were similar between groups, but nonoctogenarians had higher levels of glycated hemoglobin (6.5%1.4% vs 7.6%1.9%, p<0.001) and crp (3.194.94 mg / dl vs 5.136.96 mg / dl, p<0.001). compared to nonoctogenarians, less usage of statin was noted in octogenarians during the follow - up period (21% vs 37%, p=0.001). the abi index was lower in octogenarians than in nonoctogenarians (0.460.17 vs 0.510.20, p=0.002). octogenarians had more patients presenting with resting pain (26% vs 18%, p=0.022), in contrast with more disabling claudication in nonoctogenarians (12% vs 20%, p=0.008). the rates of procedure success, single or multilevel intervention, and stent implantation were similar between groups. three patients in octogenarians (two with sepsis and one with rupture of an abdominal aortic aneurysm) and seven in nonoctogenarians (four with sepsis, two with cardiogenic shock, and one with hemorrhagic stroke) died in hospital. no differences were observed with regard to the number of intensive care unit (icu) transfers after evt (8.8% vs 9.5%, p=0.792) and 30-day mave rate (12.4% vs 10.3%, p=0.466) between groups. the length of hospital stay was longer in nonoctogenarians than in octogenarians (88 vs 1112 days, p=0.002). octogenarians included a higher rate of wheelchair - bound patients (68% vs 48%, p<0.001) at presentation ; however, percentage changes in functional status after evt were not different between the groups (p=0.24). over a mean follow - up period of 3425 months (range 3112), 157 patients died (50 in octogenarians and 107 in nonoctogenarians), and the rates of overall survival in both groups were significantly different at 3 (63% vs 73%) and 5 years (45% vs 67%, p=0.004) (figure 2). there were no significant differences between groups in the rates of limb salvage (91% vs 87%, p=0.07) and scs at 3 years (51% vs 47%, p=0.297). the rates of freedom from cardiovascular death (84% vs 89%, p=0.122), nonfatal cardiovascular events (78% vs 73%, p=0.121), and stroke (86% vs 87%, p=0.504) at 3 years were similar between groups. more octogenarians died owing to noncardiovascular problems, mainly from sepsis followed by malignancy. there were no between - group differences at 3 years in the rates of freedom from macces (50% vs 55%, p=0.47) or cves (63% vs 61%, p=0.38) (figures 3 and 4). however, non - octogenarians had higher rates of nonfatal mi during the follow - up period compared with octogenarians (19% vs 8%, p=0.049). multivariate analysis showed that the octogenarian factor was not significantly associated with macces or cves. dialysis dependence and af were strong independent predictors of overall survival (or 4.44 ; 95% ci 1.7911.1 ; p=0.001 and or 2.83 ; 95% ci 1.495.35 ; p=0.001, respectively), macce (or 3.49 ; 95% ci 1.488.19 ; p=0.004 and or 2.45 ; 95% ci 1.314.45 ; p=0.005, respectively), and cve (or 3.14 ; 95% ci 1.327.48 ; p=0.009 and or 2.25 ; 95% ci 1.214.17 ; p=0.010, respectively) (table 4). during the study period, 573 patients with 728 affected legs were treated with evt. of them, ten patients were excluded (seven with acute limb ischemia and three with vasculitis - related pad). the remaining 563 patients were divided into two groups based on age (80 years or < 80 years). fifty - two patients (64 legs) were not entered into the analysis of long - term outcomes : 34 patients (40 legs) with failed procedures and 18 patients (24 legs) with a follow - up time < 30 days or in - hospital mortality. the final cohort for long - term outcome analysis included 136 patients (170 legs) in octogenarians and 375 patients (484 legs) in nonoctogenarians. octogenarians were more likely to be female and have higher incidence of af, whereas nonoctogenarians were more likely to have diabetes mellitus, dialysis dependence, history of smoking, hyperlipidemia, and a high body mass index (bmi). the hematocrit, neutrophil - to - lymphocyte ratio, platelet - to - lymphocyte ratio, and levels of serum albumin and ldl cholesterol were similar between groups, but nonoctogenarians had higher levels of glycated hemoglobin (6.5%1.4% vs 7.6%1.9%, p<0.001) and crp (3.194.94 mg / dl vs 5.136.96 mg / dl, p<0.001). compared to nonoctogenarians, less usage of statin was noted in octogenarians during the follow - up period (21% vs 37%, p=0.001). the abi index was lower in octogenarians than in nonoctogenarians (0.460.17 vs 0.510.20, p=0.002). octogenarians had more patients presenting with resting pain (26% vs 18%, p=0.022), in contrast with more disabling claudication in nonoctogenarians (12% vs 20%, p=0.008). the rates of procedure success, single or multilevel intervention, and stent implantation were similar between groups. three patients in octogenarians (two with sepsis and one with rupture of an abdominal aortic aneurysm) and seven in nonoctogenarians (four with sepsis, two with cardiogenic shock, and one with hemorrhagic stroke) died in hospital. no differences were observed with regard to the number of intensive care unit (icu) transfers after evt (8.8% vs 9.5%, p=0.792) and 30-day mave rate (12.4% vs 10.3%, p=0.466) between groups. the length of hospital stay was longer in nonoctogenarians than in octogenarians (88 vs 1112 days, p=0.002). octogenarians included a higher rate of wheelchair - bound patients (68% vs 48%, p<0.001) at presentation ; however, percentage changes in functional status after evt were not different between the groups (p=0.24). over a mean follow - up period of 3425 months (range 3112), 157 patients died (50 in octogenarians and 107 in nonoctogenarians), and the rates of overall survival in both groups were significantly different at 3 (63% vs 73%) and 5 years (45% vs 67%, p=0.004) (figure 2). there were no significant differences between groups in the rates of limb salvage (91% vs 87%, p=0.07) and scs at 3 years (51% vs 47%, p=0.297). the rates of freedom from cardiovascular death (84% vs 89%, p=0.122), nonfatal cardiovascular events (78% vs 73%, p=0.121), and stroke (86% vs 87%, p=0.504) at 3 years were similar between groups. there were no between - group differences at 3 years in the rates of freedom from macces (50% vs 55%, p=0.47) or cves (63% vs 61%, p=0.38) (figures 3 and 4). however, non - octogenarians had higher rates of nonfatal mi during the follow - up period compared with octogenarians (19% vs 8%, p=0.049). multivariate analysis showed that the octogenarian factor was not significantly associated with macces or cves. dialysis dependence and af were strong independent predictors of overall survival (or 4.44 ; 95% ci 1.7911.1 ; p=0.001 and or 2.83 ; 95% ci 1.495.35 ; p=0.001, respectively), macce (or 3.49 ; 95% ci 1.488.19 ; p=0.004 and or 2.45 ; 95% ci 1.314.45 ; p=0.005, respectively), and cve (or 3.14 ; 95% ci 1.327.48 ; p=0.009 and or 2.25 ; 95% ci 1.214.17 ; p=0.010, respectively) (table 4). our results show that the safety and efficacy of evt in terms of procedure success, 30-day maves, functional improvement, limb salvage, and scs are comparable between octogenarians and nonoctogenarians. although younger patients had more traditional risk factors, age did not increase the risk of long - term vascular events over the 10-year study period. regular dialysis and af were independent predictors for long - term survival, macces, and cves. pad is a progressive disease of atherosclerosis, and pad - related death and disability has increased globally and regionally in the past 20 years.13 there are few reports comparing cardiovascular risk factor profiles between octogenarians and nonoctogenarians, especially in the asian countries. our findings that nonoctogenarians with pad had a higher bmi and more atherosclerotic risk factors are in agreement with an earlier study of octogenarians and septuagenarians, which suggested that younger pad patients have more comorbid disease.17 on the contrary, more patients with af and female sex were noted with pad in octogenarians. patients with symptomatic pad were considered candidates for revascularization, either endovascular or surgical therapy. untreated chronic cli, an advanced stage of pad, is associated with a dismal prognosis.1,13 instead, patients with cli who undergo successful revascularization survive longer and experience greater improvements in quality of life when compared to patients treated conservatively or with primary amputation.5,12 the benefits of revascularization may be attenuated when taking into account the aging of the population, which significantly increases the number of elderly patients at high risk of perioperative mortality due to limb - saving procedures, adverse cardiovascular events, and other medical comorbidities.912 there are no specific guidelines regarding revascularization procedures in elderly patients with symptomatic pad. the rates of procedure success, number of icu transfers, and 30-day maves were similar between groups. nonoctogenarians had a longer hospital stay when compared to octogenarians, which was related to more tissue inflammation and debridement surgery in these patients. our results are consistent with previous reports911,14 showing that minimally invasive evt is safe in octogenarians and does not increase the risk of periprocedural complications as compared to nonoctogenarians. recent advances in endovascular techniques and devices, coupled with improved quality of medical care, render evt a tempting first - choice treatment in very elderly vascular patients. although more octogenarians, associated with age - related neurologic or musculoskeletal problems, were wheelchair - bound at presentation than nonoctogenarians, no significant difference was found in both groups regarding the changes of functional status 6 months after evt. these findings suggested that evt has beneficial effect in improving ambulatory function in elderly patients. the long - term survival rate of octogenarians in our study remained lower than that of nonoctogenarians (63% and 73% at 3 years and 45% and 67% at 5 years, respectively). although cardiovascular death remained a major cause of death in this study cohort (35%, 55/157), no differences were observed in subsequent cardiovascular deaths between groups. the leading cause of death in octogenarians was infectious disease (52% due to sepsis and pneumonia), which reflects the impaired immune and functional status in the aging population. previous reports have shown that elderly patients are at higher risk of adverse events following pad treatment because of multiple comorbidities and relatively reduced physiologic reserve.2 however, reported outcomes of evt for octogenarians mainly focused on mortality, amputation, and reintervention in prior studies.915,17,18 long - term data regarding late cves in symptomatic pad patients are scarce.19 we included major amputation in our cve outcomes, which led to more pad - related predictors. in this study, only nonfatal mi reached the marginal significance between groups (p=0.049), which may be associated with the longer life expectancy and more atherosclerosis risk factors in nonoctogenarians. after successful evt, octogenarians showed no increase in the rates of macces and cves as compared to nonoctogenarians. in addition, late vascular events can be prevented by optimal medical care, such as increased use of beta - blockers periprocedure, coupled with antiplatelet agents, statin and angiotensin - converting enzyme inhibitors, or angiotensin receptor blockers during long - term management.2024 the cox regression model showed that dialysis dependence and af are independent risk factors predicting subsequent cardiovascular events despite age stratification. af is an independent risk factor for survival in patients with cli.25 in this study, af remained an independent predictor of survival, macce, and cve outcomes. the prevalence of af is higher in patients with systemic atherothrombosis.26,27 severe pad and a high chads2 (congestive heart failure, hypertension, age 75 years, diabetes mellitus, stroke) score28 were observed in many of our patients, which might explain why af played an important role in late cardiovascular events. dialyzed patients with pad have a higher rate of mortality and cardiovascular events.29,30 despite improved limb salvage from evt in dialyzed patients with pad, the overall survival in this group remained poor.31,32 our results are consistent with prior reports,33,34 wherein dialysis is an important predictor of mortality and subsequent cardiovascular events in pad patients when other risk factors are adjusted. traditional risk factors, coupled with vascular inflammation and malnutrition, were associated with general atherosclerosis in dialyzed patients with pad. first, it was a single - center, observational study using a prospective database. treatment allocation was made at the discretion of the operator and the patient s policy of reimbursement. second, the fact that all patients were treated at a single center in taiwan opens up the possibility of referral / selection bias based on the current practice of this group. as with all observational studies, the reported association may not represent the underlying causality. the unavoidable risk of selective bias and differences in long - term survival not due to exposure to the treatment being studied threatens the observations made in a cohort study. third, underutilization of statins may have negatively impacted our ability to prevent late ischemic events, which may relate to reimbursed policy and less hyperlipidemia in octogenarians and dialyzed patients. finally, we did not investigate the mechanisms underlying the effect of af on pad. first, it was a single - center, observational study using a prospective database. treatment allocation was made at the discretion of the operator and the patient s policy of reimbursement. second, the fact that all patients were treated at a single center in taiwan opens up the possibility of referral / selection bias based on the current practice of this group. as with all observational studies, the reported association may not represent the underlying causality. the unavoidable risk of selective bias and differences in long - term survival not due to exposure to the treatment being studied threatens the observations made in a cohort study. third, underutilization of statins may have negatively impacted our ability to prevent late ischemic events, which may relate to reimbursed policy and less hyperlipidemia in octogenarians and dialyzed patients. finally, we did not investigate the mechanisms underlying the effect of af on pad. in conclusion, evt in octogenarians is feasible, without an increased risk of periprocedural complications. however, the rates of limb salvage, scs, long - term cves, and macces were comparable between groups. dialysis dependence and af are independent predictors of long - term survival, macces, and cves. | purposeto investigate the clinical outcomes of endovascular therapy (evt) in octogenarians and nonoctogenarians with peripheral arterial disease.methodsa retrospective analysis of 511 patients (654 affected legs) who underwent evt between july 2005 and december 2013 was conducted in a prospectively maintained database. immediate results and long - term vascular outcomes were analyzed and compared between octogenarians and nonoctogenarians.resultsoctogenarians were more likely to be female and have atrial fibrillation (af), whereas nonoctogenarians had higher rates of obesity, claudication, and medical comorbidities. there were no differences in the rates of evt success, 30-day major adverse vascular events, and 6-month functional improvement between groups. over the 10-year follow - up period, the rates of 3-year limb salvage, sustained clinical success, freedom from major cerebrovascular and cardiovascular events, and composite vascular events were similar between groups, but the survival rate was better in nonoctogenarians than in octogenarians (73% vs 63%, respectively, p=0.004). in cox regression analysis, dependence on dialysis and af were significant predictors of death (odds ratio [or ] 4.44 in dialyzed and 2.83 in af patients), major cerebrovascular and cardiovascular events (or 3.49 and 2.45), and composite vascular events (or 3.14 and 2.25).conclusionevt in octogenarians was feasible, without an increased risk of periprocedural complications. the rates of limb salvage, sustained clinical success, and long - term vascular events were comparable between groups. dialysis dependence and af are independent predictors for poor prognosis in patients with peripheral arterial disease. however, these observations require further confirmation in larger scale studies. |
dairy products are essential components of a healthy diet for human and are very popular in all age groups owing to their high nutritional value and pleasurable flavor [13 ]. recent years have seen greatly increasing production and consumption of dairy products in the world [4, 5 ]. an important factor that influences the textures and flavors of dairy products is the protein content, which has been adopted as a quality index by many industries. unfortunately, because the traditional kjeldahl method for analysis of total nitrogen content as an indication of protein levels is insufficient to distinguish between organic nitrogen and protein and nonprotein sources, unethical manufacturers deliberately added some illegal exogenous materials to dairy products to obtain an incorrectly higher readout of apparent protein content [68 ]. one of the most notorious exogenous adulterants used in dairy products is melamine, chemically known as 2,4,6-triamino-1,3,5-triazine [911 ]. melamine is a nitrogen - rich (about 66.6%) heterocyclic triazine produced on a large scale (1.2 million tonnes in 2007) [12, 13 ]. it is primarily used in the synthesis of melamine formaldehyde resins for the production of paper finishers, flame retardant, commercial filters, moulding compounds, wrinkle - free textile, and many other materials [1416 ]. as a very cheap and readily available industrial material, melamine was added to various food and food - related products, including milk, infant formula, frozen yogurt, biscuits, candy, coffee drinks, pet food, and feed [1719 ], to increase the nitrogen level and to reduce costs. although melamine has low toxicity by itself, when combined with cyanuric acid and uric acid, it can form insoluble crystals, which may lead to kidney stones, eventual renal failure, and ultimately death. the most severe outbreak of melamine contamination occurred in 2008 in china, which had caused kidney stones in thousands of people and at least six deaths of young children. to prevent further contamination and frauds, maximum limits the emergent need for regulation of melamine has promoted extensive and intensive laboratory efforts to develop rapid, widely available, and cost - effective methods for analysis of melamine in various samples [1, 12, 18, 2224 ], including capillary electrophoresis, high - performance liquid chromatography (hplc) [26, 27 ], lc with mass spectrometry (lc - ms) [28, 29 ], gas chromatography with ms (gc - ms) [30, 31 ], micellar lc [32, 33 ] matrix - assisted laser desorption / ionization ms (maldi - ms), nuclear magnetic resonance spectroscopy, vibrational spectroscopy and imaging [36, 37 ], chemiluminescence analysis [38, 39 ], electrochemical analysis, and immunoassay. among various methods, near - infrared (nir) spectroscopy, as a rapid and nondestructive analytical method widely used in food analysis [42, 43 ], is promising for high - throughput screening and detection of melamine. although nir has a comparatively lower sensitivity and higher detection limit compared with other methods, it was demonstrated to be sufficient in detecting excessive use of melamine in dairy products and could provide a convenient tool to rapidly screen and quantify melamine in chinese markets [17, 45 ]. for quantitative analysis, chemometric methods for multivariate calibration (mvc), such as partial least squares (pls), support vector machines (svm), and artificial neural network (ann), although mvc combined with nir spectroscopy has shown good accuracy and precision in analysis of melamine for some specific samples, the practical application of ordinary mvc to different brands / types of samples can be largely limited because the prediction of a new sample from an uncalibrated group would be subject to a significant bias due to matrix effect. while calibration transfer is a complicated procedure with high requirements of the practitioners ' expertise and its performance can be influenced by many factors, standard addition method is a relatively easy - to - use tool for analysis of samples with complex compositions and from diverse origins. net analyte signal (nas) theory has been proven to be useful in the development of new multivariate calibration methods, evaluation of the figures of merit of multivariate calibration, variable selection, outlier diagnosis, and data preprocessing. nas is based on an intuitive idea, namely, separating a part of the signal that is directly related to the concentration of the analyte of interest from that of interfering components. using the euclidean norm of the computed nas vector,, the multivariate calibration can be reduced to a simple univariate linear regression, which is especially useful for model validation and prediction. a multivariate standard addition method using nas (sanas) [49, 50 ] has been suggested and demonstrated to be effective in overcoming the matrix effect or indirect interferences. the objective of this work was to study the feasibility of using multivariate standard addition method and nir spectroscopy for rapid quantification of melamine in milk powders of different brands / types. to control the possible variations in preparation and measurement of added samples, the sanas method was used to analyze different brands / types of milk powder samples. ten different brands / types of milk powder samples were collected from the quality inspection departments of producers as shown in table 1. the shelf lives of all the samples were equal or over six months and, to the date of analysis, no sample has expired. the milk powder samples were kept in a dark, cool, and dry area at about 25c with complete packaging before preparation and analysis. a melamine (sinopharm chemical reagent co., ltd., shanghai, china) gradient consisting of 5 levels, namely, 0.01, 0.02, 0.04, 0.08, and 0.12 percent (w / w%), together with the unadulterated samples, was prepared for each of the 10 batches. therefore, 60 adulterated milk powder samples were obtained and used for analysis by sanas. for standard addition, a designed gradient of 4 melamine standards was added to each level of the above 60 samples as listed in table 2. the nir diffuse reflectance spectra of milk powder samples were measured in the spectral range from 4000 to 10000 cm on an antaris ii fourier transform - nir spectrometer (thermo electron co., waltham, massachusetts, usa) using the restlt 3.0 software. all samples were measured with a pbs detector and an internal gold background as the reference. therefore, each spectrum had 1557 individual data points for chemometric analysis. for each object, 32 scans were performed and more scans did not enhance the spectral signals significantly. for a detailed description of the net analyte signal (nas) theory, one can refer to. in this work, spectral data like nir, the nas of a chemical component is defined as the part of its pure spectrum that is orthogonal to the spectral space spanned by all the interfering components. the nas vector of the kth component in a multicomponent mixture is defined as (1)nask = irkrk+sk, where rk is a matrix whose columns contain the pure spectrum of each component in the mixture except the kth component ; sk is the pure spectrum of the kth component ; and i is a unit matrix and the superscript the spectral variations caused by instrumental and environmental disturbances are also included in rk. using the data matrix of calibration mixtures reconstructed by principal components analysis (pca) or partial least squares (pls), a rank annihilation procedure is adopted to compute rk:(2)rk = rrecrc^kt, where rrec is the pca- or pls - reconstructed data matrix of interfering components using a significant components ; c^k is the analyte concentration vector ck explained by the a significant components ; and r is a vector including the spectrum of the kth analyte. although r can be the pure spectrum of analyte k, sk, or the spectrum of a mixture including analyte k, the pure spectrum sk is the best choice because it contains maximal information on the kth analyte. is a scalar factor which can be computed as (3)=1c^ktrrec+r. to do standard addition, a set of n standard solutions of the kth analyte were added to each of the samples. the nir data of the serial spiked samples were collected in the matrix, rsa (n p), where p is the number of nir channels. the spectrum of a sample without standard addition is collected in a column vector, run. by subtracting run from each column of rsa, one can obtain a matrix, rs (n p), which contains the spectra of the standards in the presence of the matrix effect. rs is subject to pca and the reconstructed rs is used to rebuild rsa and rsa, rec is obtained, and then the matrix of interfering components, rk, can be readily computed according to (2) and (3). subsequently, the nas vectors of the kth analyte for the standard addition samples can be computed as(4)nassa, k = irkrk+rsa, rec. by plotting the euclidean norm of the row vectors of nassa, k (n p) against cs, the standard addition curve as for the univariate sa can be obtained to derive the concentration of kth analyte in the unknown sample. all the data analysis was performed using matlab 7.10.0 (r2010a) platform (mathworks, usa). the data preprocessing and sanas algorithms were performed based on in - house computational coded scripts written by authors in matlab. the nir spectra of the original milk powder samples and pure melamine as well as the melamine - adulterated samples are demonstrated in figure 1. for ease of peak attribution, chemical bonds are denoted as atom atom, where an atom can be carbon (c), hydrogen (h), oxygen (o), and nitrogen (n). for the spectra of milk powder, the peak around 4258 cm is the combination absorbance of c h symmetric stretching and c h bending, and those at 4335 cm can be attributed to the combination absorbance of c h antisymmetric stretching and c h bending. other peak assignments are as follows : 4750 cm, combination of the basebands of n h stretching and bending ; 5157 cm, combination of the basebands of o h stretching in various groups ; ~6500 cm, the first overtone of n, the most significant difference is the intensive peak of melamine at 6811 cm, which could be attributed to the baseband of n h antisymmetric stretching. figure 2 demonstrates the second - order derivative (d2) spectra of the original and melamine - adulterated milk powder samples. however, because the added concentrations of melamine were very low (0.01~0.12%, w / w), no significant changes were found from the spectra of the adulterated milk powder by the naked eye. multivariate calibration models were developed on the raw and d2 spectra using sanas. for each unknown sample, in order to compute the nas vector, the spectrum of the original sample was subtracted from each of the melamine - spiked samples to obtain the matrix rs. the resultant spectra in rs for the sample q1 in table 1 are plotted in figure 3. seen in figure 3, the high similarity between the raw spectra in rs and that of pure melamine indicates that the computation of rs using the method proposed in sanas was very effective and helpful for accurate estimation of the nas vectors. to rebuild rs, rsa, because there were only 4 columns in rs and its data structure was simple, the number of primary pcs was estimated according to an intuitive criterion that 95 percent of the total variances of rs should be explained. the nas vectors of the 4 standard - added samples were computed according to (2)(4). figure 4 demonstrates the computed nas vectors of the 4 standard addition samples for the milk powder q1. theoretically, the melamine level in an unknown sample could be estimated by plotting the euclidean norm of the computed nas vectors, nassa, k, against the concentrations of added standards, cs. however, because the number (60) of unknown samples to be analyzed was large, least squares regression (lsr) was performed between nassa, k and cs:(5)nassa, k = acs+b. by setting the value of nassa, k to be zero, the melamine level of the unknown samples can be computed as cunknown = b / a. for all the 60 unknown samples, the correlation coefficients (r) of the above lsr were over 0.953, indicating that the computation of nas vectors was very accurate. the prediction results of the 60 melamine - adulterated milk powder samples are summarized in table 3. seen in table 3, the root mean squared error of prediction (rmsep) of melamine ranged from 0.0012 to 0.0029 with different levels of melamine to be analyzed. moreover, the prediction performance by sanas using the raw spectra and d2 spectra was similar although the results with d2 spectra seemed to be slightly better than those by the raw spectra, indicating that the unwanted spectral variations caused by baseline shifts were well controlled during standard addition. the predicted melamine levels were plotted against the reference values as shown in figure 5, also indicating that the prediction errors were low and approximately uniform for different melamine levels to be analyzed. to further evaluate the figures of merit of the method, the selectivity, sensitivity in terms of limit of detection (lod), linearity (pearson 's r), and the accuracy and precision in terms of mean relative standard deviation (rsd) were computed and listed in table 4. in china and the us, the maximum residue levels (mrl) for infant formula are 1.0 mg / kg and 2.5 mg / kg for milk and other dairy products, respectively. although the lod (0.0025%) of this method was much worse than the regulation standards, this method provides the potential of rapid analysis and screening of the frauds in chinese markets, where the practical melamine contents were much higher (up to 2563 mg / kg). the feasibility of using nir and sa for rapid quantification of melamine in different brands / types of milk powders was investigated. the analysis results for the 10 batches of melamine - adulterated milk powder samples demonstrate that sanas is an effective method for sa multivariate calibration, which can visualize and control the spectral variations caused during sa in univariate regression. moreover, the calibration accuracy was not significantly influenced by melamine levels to be analyzed. compared with traditional multivariate calibration, combination of nir and sanas will provide a more practically applicable method for analysis of melamine in different brands / types of milk powder without requiring complex calibration transfer procedures. | multivariate calibration (mvc) and near - infrared (nir) spectroscopy have demonstrated potential for rapid analysis of melamine in various dairy products. however, the practical application of ordinary mvc can be largely restricted because the prediction of a new sample from an uncalibrated batch would be subject to a significant bias due to matrix effect. in this study, the feasibility of using nir spectroscopy and the standard addition (sa) net analyte signal (nas) method (sanas) for rapid quantification of melamine in different brands / types of milk powders was investigated. in sanas, the nas vector of melamine in an unknown sample as well as in a series of samples added with melamine standards was calculated and then the euclidean norms of series standards were used to build a straightforward univariate regression model. the analysis results of 10 different brands / types of milk powders with melamine levels 0~0.12% (w / w) indicate that sanas obtained accurate results with the root mean squared error of prediction (rmsep) values ranging from 0.0012 to 0.0029. an additional advantage of nas is to visualize and control the possible unwanted variations during standard addition. the proposed method will provide a practically useful tool for rapid and nondestructive quantification of melamine in different brands / types of milk powders. |
intestinal malrotation is a failure of gut to rotate completely (270 degree anticlockwise) in utero. it can cause small intestinal obstruction and strangulation in infants due to midgut volvulus. a 20-year female presented with a history of mild mid abdominal pain for 2 days. ct abdomen showed alteration of sma / smv (superior mesenteric artery and vein) axis with large bowel on the left and small bowel on the right. on laparoscopy, clumping of small bowel on right and caecum to left iliac fossa noted. operative techniques - one 10 mm umbilical port for camera and two 5 mm working ports in the flanks were used. peritoneal bands were divided with a combination of harmonic scalpel (ethicon endosurgery) and fine scissor. small bowel released from membranous adhesions, malpositioned dj flexure released and ladd bands excised. no suture fixation was used. a 14-year female presented with right sided abdominal pain, mainly early postprandial (within 1 h), on and off for 6 months. small bowel loops were to the right and caecum and appendix was up towards epigastrium and to the left. a 25-year - old female with epigastric pain on and off for 3 months was admitted with sub acute intestinal obstruction. all the patients, when asked, confirmed that symptoms were present since childhood and either ignored or treated with common household remedies. oral liquids started after 6 h and all three patients were discharge on second postoperative day. these patient, now in more than 6 months follow up, are doing well. a 20-year female presented with a history of mild mid abdominal pain for 2 days. ct abdomen showed alteration of sma / smv (superior mesenteric artery and vein) axis with large bowel on the left and small bowel on the right. on laparoscopy, clumping of small bowel on right and caecum to left iliac fossa noted. operative techniques - one 10 mm umbilical port for camera and two 5 mm working ports in the flanks were used. peritoneal bands were divided with a combination of harmonic scalpel (ethicon endosurgery) and fine scissor. small bowel released from membranous adhesions, malpositioned dj flexure released and ladd bands excised. a 14-year female presented with right sided abdominal pain, mainly early postprandial (within 1 h), on and off for 6 months. small bowel loops were to the right and caecum and appendix was up towards epigastrium and to the left. a 25-year - old female with epigastric pain on and off for 3 months was admitted with sub acute intestinal obstruction. all the patients, when asked, confirmed that symptoms were present since childhood and either ignored or treated with common household remedies. oral liquids started after 6 h and all three patients were discharge on second postoperative day. these patient, now in more than 6 months follow up, are doing well. when symptomatic, patients present with acute obstruction or chronic abdominal pain or nonspecific complaints. imaging shows small bowel in the right and colon up and to the left (figure 1a). angiography shows sma /smv axis alteration (whirl sign - sma going around smv) with possibility of intestinal ischemia. as in pediatric patients, physical examination and abdominal imaging, followed by diagnostic laparoscopy / laparotomy and if identified, ladd 's procedure is recommended to avoid the risk of midgut volvulus. small intestine to right and cecum up and to left the surgical steps consist of division of ladd 's band (figure 1b and 1c) and other congenital fibers and adhesions constricting the base of mesentery, appendectomy and functional positioning of the intestine (figure 1d) with or without fixation. at the end, widening of the mesentery base (figure 2a and 2b) and straightening duodenum descends along the right gutter, small intestine lie on the right and the caecum and ascending colon in the midline or left side of the abdomen. appendicectomy (figure 2c) helps avoiding future diagnostic confusion and also help fixation of caecum. ladd 's bands being dissected twisted mesentery getting released brodedned mesentry untwisted the sma / smv axis it is reported in some series that pathophysiology of pain and other chronic symptoms may not correlate with the extent of radiological anomaly seen, especially the obstructive component. all our cases had twist of the narrowed mesenteric pedicle that was easily reversed after peritoneal band lyses. peritoneal bands may have a restrictive effect on normal duodenal motility and duodenal malrotation (figure 2d) often coexists with other parts of intestinal malrotation. complex neurohumoral or neuromuscular changes that occur as the result of release of entrapped bowel also contribute to symptom resolution. abnormal positioned ligament of traitz in malrotated duodenum there is evidence that laparoscopic ladd 's procedure in pediatric age group is safe and gives similar results as in open procedure. our result agrees with other studies showing laparoscopic ladd procedure as safe and effective with the advantage of minimally invasive approach in adult patients with intestinal malrotation without midgut volvulus. if the embryological origin of the malrotation is kept in mind and the systematic steps are followed to divide the bands and release the bowel rather than try to bring caecum to right and small bowel to left, the procedure becomes straightforward and can be accomplished laparoscopically much easily. | intestinal malrotation is rare in adults. patients may present with acute obstruction or chronic abdominal pain. these symptoms are caused by ladd 's bands and narrow mesentery resulting from incomplete gut rotation. barium, computed tomography (ct) and magnetic resonance imaging (mri), angiography and sometimes explorative laparotomy are used for diagnosis. ladd 's procedure is the treatment of choice but data about laparoscopic approach in adult is scarce. we report three cases of laparoscopic correction of adult malrotation presenting with chronic abdominal pain. the diagnosis is made by ct / mri. laparoscopic ladd 's procedure (release of bands, broadening of mesentery and appendicectomy) was performed via three ports. procedure time 25 - 45 min. all patients were discharged on postoperative day 2. at 6 month follow - up, all are symptom free. laparoscopic ladd 's procedure is an acceptable alternative to the open technique in treating chronic symptoms of intestinal malrotation in adults. |
overactivation of mineralocorticoid receptor pathways in choroidal vessels have been noted in experimental models of central serous chorioretinopathy (cscr). mineralocorticoid antagonism through oral agents such as eplerenone has subsequently demonstrated success in the treatment of persistent cscr. significant subretinal fluid can also be encountered in select cases of neovascular age - related macular degeneration (amd) and polypoidal choroidal vasculopathy that can present challenges to successful treatment. in this report, successful reduction in subretinal fluid in a case of polypoidal choroidal vasculopathy is demonstrated. a 72-year - old woman presented with a gradual, painless decrease in vision in the left eye. on examination, visual acuity was 20/40 in the right eye and 20/150 in the left eye. biomicroscopic examination of the left eye revealed significant macular subretinal fluid with the absence of any evident hemorrhage, drusen, retinal pigment epithelial changes, or exudate in either macula. optical coherence tomography confirmed the presence of subretinal fluid with shaggy photoreceptor outer segments, absence of intraretinal fluid, and some outer segment / inner segment junction changes (fig. intravenous fluorescein angiography (ivfa) was deferred due to a history of significant allergic reaction to ivfa in the past. further history assessment revealed a recent use of oral steroids (2 months previously). b.i.d. based on a presumed diagnosis of cscr and was followed up for 2 weeks initially to ensure improvement, given other etiologies could not be conclusively ruled out in the absence of ivfa. at the 2-week follow - up, visual acuity the follow - up was extended to 4 weeks. up to week 6, visual acuity remained 20/100, and the subretinal fluid had further decreased, but some exudate was evident on examination and oct (fig. 1c) that suggested an alternative diagnosis may be possible. after review with the patient, the decision was made to premedicate the patient with steroids and benadryl and to proceed with fa / indocyanine green, which revealed a network of peripapillary polypoidal choroidal vasculopathy with active leakage (fig. 2). intravitreal avastin was added to the treatment regimen, and the patient was maintained on oral eplerenone at 25 mg p.o. four weeks later, nearly all subretinal fluid had resolved and the exudate had regressed (fig. 1d), and vision had improved to 20/50. up to the 1-year follow - up, the patient has remained stable with absence of intraretinal or subretinal fluid or exudate on eplerenone at 25 mg p.o. polypoidal choroidal vasculopathy is a variant of neovascular amd that is characterized by branching subretinal aneurysmal polyp - like vessels. polypoidal choroidal vasculopathy is frequently characterized by subretinal hemorrhage, pigment epithelial detachment, or exudate, in addition to subretinal fluid. the everest study pointed toward the efficacy of photodynamic therapy as being superior to anti - vegf monotherapy in these lesions, which is further suggestive of its distinction from neovascular amd. the pathogenesis of polypoidal choroidal vasculopathy remains elusive, but the choroidal vasculature has been implicated, with indocyanine green angiography elucidating these polyp - like vessels best. while the natural history and disease course of polypoidal choroidal vasculopathy and cscr differ significantly, they share an implication of abnormal dilation of the choroidal vasculature in their presumed pathophysiology. this anatomic overlay begs the question of whether a deeper overlap of polypoidal choroidal vasculopathy and cscr exists in some patients than has previously been realized. the lack of a diffusely leaky choroid argues against a classic presentation of cscr in this case, and the identification of polyps in the setting of exudates is more consistent with a typical case of polypoidal choroidal vasculopathy. it is possible that some patients with polypoidal choroidal vasculopathy develop a secondary focal reactive retinal pigment epithelium dysfunction that leads to a cscr type of response. this secondary accumulation of subretinal fluid with associated shoddy photoreceptor outer segments may independently lend itself to a response with eplerenone treatment. alternatively, it is plausible that mineralocorticoid receptor antagonism may add an adjunctive efficacy in the setting of subretinal fluid from both etiologies, particularly given a potentially shared choroidal pathologic origin. in this case, oral eplerenone demonstrated efficacy as an adjunct to intravitreal anti - vegf in a case of polypoidal choroidal vasculopathy. to the authors knowledge, this is the first report of eplerenone use in the setting of polypoidal choroidal vasculopathy. further research is needed to better elucidate the precise role of mineralocorticoid antagonists in polypoidal choroidal vasculopathy. this study complied with the guidelines for human studies, subjects were given informed consent, and the study protocol was approved by the committee for human research. | overactivation of mineralocorticoid receptor pathways has been implicated in the pathophysiology of central serous chorioretinopathy (cscr). recently, mineralocorticoid receptor antagonists such as eplerenone have demonstrated success in treating subretinal fluid in cscr. this case demonstrates a patient who was initially presumed to have subretinal fluid secondary to cscr and was started on a trial of oral eplerenone. it quickly became evident that her subretinal fluid was secondary to a peripapillary polypoidal choroidal vasculopathy network, but she demonstrated a significant improvement with oral eplerenone. to the authors ' knowledge, this is the first case of eplerenone use to treat polypoidal choroidal vasculopathy. |
periodontal injury with localized destruction often occurs due to inadvertent force applied to the periodontium. such injury could be related to some psychosocial condition (i.e., stress related), habitual, or related to the patient 's profession. notching of the associated tooth with resultant extrusion and proclination and periodontal destruction with or without periodontal abscess that is often seen in carpenters, cobblers, tailors, and musicians is due to the common habit of keeping nails, sewing needles, or a musical instrument (as the case may be) between their teeth. in this case report we describe an electrician who habitually used his teeth to strip the rubber coating off electrical wires. the habit resulted in extrusion and proclination of the incisor and exacerbation of periodontal destruction, leading to recurrent periodontal abscess formation. a 31-year - old male presented to the department of periodontics, manipal college of dental sciences, manipal, india, with recurrent swelling and pain in the maxillary anterior teeth over the previous 6 months. the pain was dull and slightly increased whenever he used that particular tooth for biting. the maxillary right central incisor was found to have a 5 mm pocket mesiolabially and a 6 mm pocket mesiopalatally. the incisal edge in the center of the tooth had a notch (abraded). the notching of the incisal surface at the center can also be seen radiographic evaluation revealed the presence of a vertical defect [figure 2 ] mesial to the right central incisor. when the clinical findings were correlated to the radiographic findings, it was evident that the cause of such localized destruction was either trauma or an endodontic - periodontic lesion. since the tooth was not discolored and not tender on percussion, we sought for history of possible trauma. iopa shows a vertical defect mesial to the maxillary right central incisor enquiries related to his work as an electrician revealed that he often used his incisors to strip the outer rubber coating off electrical wires. he would hold the wire between his maxillary anterior and mandibular anterior teeth and pull the wire, thus removing the outer tubing and exposing the tungsten core. in view of the localized destruction and the recurrent attacks of periodontal abscess, it was evident that the lesion was related to his occupation. based on the history and the clinical and radiographic findings, we made a diagnosis of chronic periodontal abscess. the relationship between the recurrent attacks of periodontal abscess and periodontal destruction and his professional habit was explained to him and he was advised to stop the habit. oral prophylaxis was given and the patient was advised to return after 15 days for surgical treatment. open flap debridement in the form of a papilla preservation flap, combined with a regenerative periodontal surgical procedure, was done. the combined regenerative procedure consists of citric acid root conditioning, bone graft (bio - oss, geistlich biomaterials), and guided tissue regeneration (gtr) (bio - gide g) [figures 3 and 4 ]. the patient was recalled ater 15 days for suture removal and then advised to come for follow - up at 6 months. after debridement mesial to the maxillary right central incisor, the twowalled defect on the mesial surface and dehiscence in the facial aspect can be seen papilla preservation flap sutured after combined regenerative procedures there are several etiologies for periodontal abscess formation. chronic continuous trauma, pernicious bruxism is one of them. a subgingival calculus acts as a continuous source of infection. continuing trauma to the periodontium results in the destruction of the periodontal ligament fibers and abscess formation. this was clearly explained to the patient and he was advised to stop the habit. | we report an unusual case of recurrent periodontal abscess in a 31-year - old male electrician due to his habit of using his teeth as a tool for stripping electrical wires. the patient was not aware of the consequences of this habit. clinically, there was presence of moderate depth of periodontal pocket around the tooth and, radiographically, there was a vertical defect mesial to the involved teeth. the patient was educated about the consequences of his habit and surgical treatment was undertaken. a papilla preservation flap with regenerative periodontal surgical procedure was done, orthodontic and restorative treatment was planned at the follow - up. this case highlights the importance of eliciting a proper and complete personal history, including occupational details. in our patient these details helped us correlate the destruction of the periodontium to the unusual etiology. |
chronic obstructive pulmonary disease (copd) is a major cause of death and disability around the world. the age - adjusted death rate of this disease is highest in low - income areas of the world including south asia and sub - saharan africa. even in high - income countries, there is a definite trend in socioeconomic related outcome with those in the lower socioeconomic status faring worse. the high economic burden this disease imposes on the individual, and the health care delivery system of a nation needs to be emphasized. in the indian context, there is limited data regarding prevalence of copd. the estimated prevalence is between 6.5% and 7.7% ; but this is by no means accurate. the nationwide prevalence of chronic bronchitis alone has been estimated to be 3.49% but this data do not include emphysema which is the other major determinant of copd. the predictors of poor outcome in indian patients admitted with acute exacerbation have variously been estimated to be hypotension, need for invasive ventilation, presence of co - morbid illness, and hypercapnia. owing to the heterogenecity of present studies and large populations in the country being out of the scope of available studies, even this data is far from complete. in the setting of kerala where this study was done, this prospective cohort study was done to determine the predictors of outcome in patients admitted with acute exacerbation of copd in a tertiary care center in the state of kerala, india. the hospital where this study was done the climate in the region is humid and the vegetation green throughout without any significant air pollution. a total of 70 patients admitted with acute exacerbation of copd in the intensive care unit (icu) between august 2013 and july 2014 were included in the study. there were no set criteria to define icu admission and was left best to the clinical judgment of the admitting physician who first saw the patient in the emergency. the only other inclusion criteria was a known clinician made diagnosis of copd with supporting spirometry or a high probability of the disease (on the basis of clinical history, history of chronic exposure to respiratory irritants, smoking history, physical examination, and chest radiograph). type ii respiratory failure was defined as hypercarbia (paco2 > 45 mm hg) (n : 3545 mm of hg) with a co - existing hypoxia (pao2 < 80 mm hg) (n : 80100 mm of hg). a peer reviewed, pilot tested, structured questionnaire was used to collect data which included sociodemographic variables, clinical variables, and investigations. data entry was done using epidata software, version 3.1 (developed by the epidata association, odense, denmark) and analysis was done using r software, version 3.1.1 (developed by overall mortality and mortality within each group of patients were expressed as number of deaths per 100 person days. survival curve was plotted using kaplan meier method and median survival period with its 95% confidence interval (ci) was calculated. the log - rank test was done for statistical association of relevant risk factors with mortality. the effect size of risk factors on mortality was calculated as hazard ratios (hrs). the study was approved by the institutional ethics committee of the hospital and has been registered with the clinical trials registry of india : ctri/2013/12/004210. the total number of patients enrolled in the study was 70 of whom 58 (82.9%) were designated as elderly (above 60 years of age). there was a general mix of both cigarette and bidi and hence an attempt was not made to differentiate between them. all the females (n = 9, 12.9%) had a history of exposure to biomass fuel in the form of firewood. none of them were smokers. majority of patients (80.0%) had history of one or more co - existing illnesses ; 19 (27.1%) had diabetes mellitus, 20 patients (28.6%) had hypertension, 29 (41.4%) had ischemic heart disease, four patients (5.7%) had past history of tuberculosis, and 32 (45.7%) had history of other significant co - morbidities (cerebrovascular accident, renal failure, leukemia, chronic liver disease, hypothyroidism, seizure disorder, and benign prostatic hypertrophy). nine patients (12.9%) were already on home oxygen therapy. on initial admission analysis of the primary parameters reflecting gas exchange / oxygen supply (arterial blood gas analysis and hemoglobin) 49 patients (70.0%) were in type ii respiratory failure and 35 (50.0%) had anemia (males < 13 g % and females < 12 g %). the major x - ray finding was hyperinflated lung fields (emphysema) (n = 51, 72.9%). signs of pneumonia were seen in 29 patients (41.4%) ; 4 (5.7%) had pneumothorax, 3 (4.3%) had bronchiectasis, 3 (4.3%) had some degree of lung fibrosis, 2 (2.8%) had a cavitatory lesion, 1 (1.4%) had a lobar collapse, and 1 (1.4%) had effusion on the chest x - ray. regarding causes of exacerbation, infection was suspected to be culprit in majority of the patients (n = 51, 72.9%). this was corroborated by clinical findings (fever / increase in purulence of sputum) and investigations (increased white cell count / positive sputum culture / chest x - ray). the mean duration of hospital stay was 6.55 days (sd of 4.29) and mean duration of icu stay was 3.67 days (sd of 3.38). the cohort constituted 459 person - days of observation, and the mortality rate was 8 per 100 person - days ; 37 (52.9%) died in hospital. median follow - up period for the entire cohort as well as for the censored was 6 days. a kaplan meier survival curve was plotted [figure 1 ] ; the median survival time was found to be 11 days (95% ci : 815). meier survival curve with 95% confidence interval for the cohort of chronic obstructive pulmonary disease patients forty - seven patients (67.14%) needed noninvasive ventilation, 32 (45.71%) needed invasive ventilation and 21 (30.0%) needed both noninvasive and invasive ventilation ; 12 patients (17.14%) did not require any source of assisted ventilation. mortality in relation to the different characteristics of the cohort was tabulated [table 1 ]. among the different characteristics, only hemoglobin status had a significant association with mortality by kaplan meier survival analysis (p = 0.001). furthermore, hr of mortality for anemia with reference to normal hemoglobin status was 2.829 (95% ci : 1.4045.702) by cox proportional hazard method. other lab parameters (liver function, renal function, electrolytes, etc.) did not have any significant association with mortality. in regression model involving clinical and laboratory parameters at the time of admission, again anemia emerged as an independent risk factor for mortality [table 2 ]. a dose - response relationship of hemoglobin with mortality could not be studied because the numbers of patients with moderate and severe grades of anemia were small. association of gender with mortality could not be studied due to very small numbers (n = 9) in female category. mortality in the cohort in the different risk groups cox proportional hazard model predicting risk factors of mortality by clinical and laboratory parameters at the time of admission cox proportional hazard model predicting risk factors of mortality from patient history in this study, males formed the predominant gender with tobacco smoking being the main etiology in them. studies from other centers in india also paint a similar picture regarding gender and etiology. females though limited in number were united by a single cause, exposure to biomass fuel in the form of firewood ; this mirrored studies across india and in other developing economies. anemia was significantly associated with mortality (hr of 2.829). on the basis of human physiology polycythemia is what is expected of the long - standing hypoxia of copd. hypoxia increases erythropoietin (epo) production in the proximal convoluted cell of the kidney which in turn enhances red blood cell (rbc) production. postulated mechanisms include anemia of chronic disease (acd), iron deficiency, vitamin deficiency, associated co - morbidities, hypogonadism, and treatment related. acd is an immune - mediated phenomenon where inflammation plays an important role in the pathogenesis. the mechanisms incriminated in causing acd are iron homeostasis dysregulation, blunted endogenous epo production, impaired bone marrow erythropoietic response, and shortened rbc survival. anemia being a risk factor for a poor outcome in copd has far - reaching implications in a country like india. india already has a high prevalence of iron deficiency anemia, especially in the rural setting. henceforth, health planners may have to consider copd patients also as a risk group for anemia and target them for correction. the postulated predictors of negative outcome in copd patients reported from other centers in india are hypotension, need for invasive ventilation, presence of co - morbid illness and the presence of hypercapnia. the sample size in this study was inadequate to find an association of these risk factors and a negative outcome. in a developing country like india frequent episodes of acute exacerbation of copd puts a great strain on the meager health resources of the nation. the wide variation reported in the predictors of outcome of copd along with the finding of this study the vastness of the nation, rural - urban divide, cultural differences, poverty, and contrasting climate are all challenging aspects of doing a study that is representative of the population at large. never the less considering the dearth of data regarding copd from kerala and from india in general, it is hoped that the information generated will help to compute an adequately powered study in future. meanwhile, family practitioners and primary care physicians may remain vigilant regarding the development of anemia in their copd patients and institute remedial measures without delay. india already has a high prevalence of iron deficiency anemia especially in the rural area, and this is compounded in the geriatric population. henceforth, health planners may have to consider copd patients also as a risk group for anemia and target them for correction. meanwhile family practitioners and primary care physicians may remain vigilant regarding the development of anemia in their copd patients and institute remedial measures without delay. in addition, the wide variation reported in the predictors of outcome of copd along with the finding of this study calls for an urgent need for more studies. | background : chronic obstructive pulmonary disease (copd) is associated with a high degree of mortality and morbidity around the world with the burden of the disease being more in the developing countries. in the indian context data is limited. this study was carried out to determine the predictors of outcome in patients admitted with acute exacerbation of copd in a rural tertiary care center in the state of kerala.materials and methods : this was a prospective cohort study. patients admitted with acute exacerbation of copd in the intensive care unit between august 2013 and july 2014 was included in the study. sociodemographic data, clinical variables, and investigations were collected. mortality with respect to relevant risk factors was compared using kaplan meier method and cox proportional hazard model.results:seventy patients were enrolled in the study of whom 58 (82.9%) were above the age of 60 years. majority of the patients (87.1%) were males. tobacco smoking was the main risk factor in them. all the females had a history of exposure to biomass fuel in the form of firewood ; none of them were smokers. majority of patients (80.0%) had a history of one or more co - existing illnesses. anemia was found to be an independent risk factor for mortality (adjusted hazard ratio : 3.167, 95% confidence interval : 1.5166.616). risk factors for poor outcome in copd patients reported from other centers in india were not found to be relevant in this study.conclusions:anemia could be an independent risk factor for mortality in copd patients. india already has a high prevalence of iron deficiency anemia especially in the rural area and in the geriatric population. henceforth, family practitioners and primary care physicians may remain vigilant regarding the development of anemia in their copd patients and institute remedial measures without delay. futhermore, the wide variation reported in the predictors of outcome of copd along with the finding of this study calls for an urgent need for more studies. |
the first open - heart surgery in gdansk took place in 1975. it was possible thanks to the gift of a pemco extracorporeal circulation machine from the netherlands to the surgery institute of the medical academy of gdansk. the article presents additional, unpublished informations which enable a new interpretation of the previously known facts. |
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the reason why exposure to common environmental antigens induces allergic responses in some people and not others remains undetermined. atopy and asthma have a complex genetic background, and multiple genes can contribute to their development through main effect, gene - gene, and gene - environmental interactions. allergen - specific cd4 + helper t - cell (th) generation is the initial event leading to the development of allergic disease. th2 subtypes are pivotal to the inflammatory cascade through the production of il-4, il-5, il-13, and il-9. th1 cells (secreting mainly il-12 and ifn-) may contribute to the chronicity and effector phase of these diseases. several genetic polymorphisms of these genes have been studied in relation to allergic diseases and asthma [13 ]. however, other important molecules have been associated with phenotypes of asthma, including tumor necrosis factor- (tnf-). this proinflammatory cytokine has been found in increased concentrations in asthmatic airways and the inhalation of tnf- has been shown to cause airway hyperresponsiveness and increased sputum neutrophil counts in healthy volunteers. tnf- is a member of the tnf gene superfamily located within the human major histocompatibility complex on chromosome 6p, linked to atopic asthma in several studies [5, 6 ]. several polymorphisms have been reported in the promoter region of the tnfa gene, with tnf-308g > a being the polymorphism most widely studied in relation to this disease. in addition to the inflammatory events, regulatory t - cell dysfunction is associated with development of complex genetic conditions such as atopy and asthma. peripheral t - cell tolerance is characterized by functional inactivation of the cells in contact with the antigen, which in turn eliminates both proliferate response and cytokine secretion [8, 9 ]. in humans, several t - cell subtypes with an immune - suppressive function, generically named regulatory t cells (treg), have been extensively studied [10, 11 ]. the main role of all these cell subsets is to maintain the integrity of the body by avoiding excessive immune responses that may result in harmful immune pathology, as well as preserve a state of tolerance to innocuous substances. il-10 and tgf- secreted by these tregs play an important role in the immune regulatory response [1315 ]. several common polymorphisms have been identified in the promoter region of both cytokines, including 1082g > a and 592c > a for il10 and 509c > t for tgfb genes, some of these polymorphisms being associated with allergic diseases [1619 ]. olive tree pollen is one of the most important causes of respiratory allergy in the mediterranean area. olea europaea pollen induces mainly nasal and conjunctive symptoms, although it may also induce asthma exacerbations in areas with high levels of o. europaea pollen in the atmosphere. in jan, a region in southern spain, there is a very high level of pollen (500 to 1000 grains / m during pollen season, with peaks of more than 5000 grains / m) and a high prevalence of asthma. to date, at least 20 proteins with allergenic activity have been described in olive pollen. among them, ole e 1 is the most frequent sensitizing allergen. besides ole e 1, twelve additional allergens have also been isolated and purified from olea europaea pollen extract, some of which are major allergens in areas with high levels of pollen exposure, such as ole e 2 and ole e 10 [21, 22 ]. previously our group described specific genetic and environmental factors associated with olive pollen allergy [2327 ], as also a strong association between ole e 10 and ole e 2 specific sensitizations and bronchial asthma clinical phenotype, being these sensitizations restricted by different hla class ii antigens. more recently we have described how, during the pollen season, olive pollen allergic patients showed a statistically significant decrease of tgf- (regulatory cytokine). this result was consistent with a significant decrease in relative foxp3 mrna expression (marker of regulatory t - cell cytokines) and with the lower number of regulatory t cells, indicating a lack of regulatory mechanisms in olive pollen allergic subjects during the pollen season. the subjects were selected from a region in southern spain with particularly high pollen counts during the pollen season and a high prevalence of asthma. taking into account all of these previous results, we analyzed the role of 6 polymorphisms of genes previously associated with allergy and asthma, in a population of olive pollen allergic patients, with an extremely high incidence of asthma : tnfa (g-308a, c-857 t, and c-1031 t) as proinflammatory gene and il10 (c-571-a and a-117 g) and tgfb (c-509 t) as genes related to regulatory response. one hundred forty - six unrelated patients were recruited at the allergy service of the complejo hospitalario de jan. all patients fulfilled the following criteria : seasonal rhinitis and/or asthma from april to june, a positive skin prick test for o. europaea pollen extract (alk abell, madrid, spain), and no previous o. europaea immunotherapy. fifty healthy subjects from the same geographic area were recruited as a control group. clinical assessment performed in these patients patients recorded symptom scores, drug requirements, and peak expiratory flow rates (pefr) every day from april to june (pollen season). individual nasal and eye symptoms (sneezing, blockage, running, redness, and itching) and chest symptoms (breathlessness, wheezing, and tightness) were recorded on a scale of 03 (0 = no symptoms ; 1 = mild symptoms ; 2 = moderate symptoms ; 3 = severe symptoms). an asthma day fulfilled at least one of the following criteria : asthma symptoms score 2, morning pef 20% lower than the mean morning pef of the last 7 days before pollination, and daytime use of salbutamol twice or more compared with the mean use of the last 7 days before pollination. olive tree pollen and olive pollen allergens were isolated as previously was described [29, 30 ]. total serum ige levels and specific o. europaea extract ige antibodies were determined by pharmacia systems (ige enzyme immunoassay and uni - cap, uppsala, sweden). allergen - specific ige antibody measurements (ole e 1, ole e 2, and ole e 10) of allergic sera were performed by enzyme - linked immunoassay (elisa). all 146 patients and 50 controls were tested for olive pollen allergy by a skin prick test with o. europaea whole extract and olive pollen purified allergens, following the recommendations of the european academy of allergy and clinical immunology (eaaci). the patients were also tested with a panel of common aeroallergens, including dermatophagoides pteronyssinus, blattella germanica, dog and cat dander, alternaria alternata, aspergillus fumigatus, cladosporium herbarum, lolium perenne, cynodon dactylon, cupressus sempervirens, platanus acerifolia, artemisia vulgaris, chenopodium album, salsola kali, and parietaria judaica (abell, madrid, spain). tnf- and il-10 sera levels were analyzed by flow cytometry, using the bd cytometric bead array (cba), human th1/th2 cytokine kit (becton dickinson, bd, san diego, ca). flow cytometric analysis was performed using a facscalibur flow cytometer (bd immunocytometry systems, san jose, ca). tgf- sera levels were analyzed by a commercial elisa (bd, san diego, ca, usa). genomic dna from all individuals was genotyped for 6 polymorphisms : tnfa (g-308a, c-857 t, and c-1031 t), il10 (c-571-a and a-1117 g), and tgfb (c-509 t). polymorphisms were analyzed according to the applied biosystems allelic discrimination assay - by - design protocol (ab-7500 real time pcr system). single nucleotide polymorphisms (snps) in research and their identifier names, locations, alternative names, and dbsnp identification are shown in table 1. comparisons of phenotypic (olive pollen sensitized versus controls, asthmatic versus rhinitis) or genotypic frequencies between groups were measured by fisher 's exact test or by chi - square test. cochran and mantel - haenszel and 2-factor anova tests were used for the statistical comparison of clinical parameters (qualitative and quantitative, resp.) between sensitized and nonsensitized groups. multiple regression analysis was used to examine quantitative traits (total ige, specific ige to o. europaea whole extract, specific olive pollen allergens ige, and soluble cytokines serum levels). the control group included 33 females (66%) and 17 males (34%), with a mean age of 37.6 years (range 2358 years). these individuals were selected from the same geographical area and were free from any allergic symptoms. all the allergic subjects (n = 146) showed significant ige antibody levels against pollen crude extract, but different frequencies of sensitization were observed for the purified o. europaea allergens (table 2). ole e 1, ole e 2, and ole e 10 are major allergens in our population (> 50% of recognition frequency). genotype and allelic frequency distribution in the patient and control groups and the genotype and allelic distribution according to asthma or rhinitis in our patient population are shown in table 3. the only statistically significant polymorphism associated with o. europaea allergy was related to the tgfb - c509-t polymorphism. we found a statistically significant increase in the phenotypic percentage of the ct heterozygous genotype in patients compared with controls (56.8% versus 40%, p = 0.03, odds ratio, or, 1.97 ; 95% confidence interval, ci, 1.023.8) (table 3). the sera of ct heterozygous patients showed the lowest levels of soluble tgf- (10849.71 12613 pg / ml) homozygous patients, but the differences were not statistically significant (data not shown). when we analyzed the genotype distribution of the 6 polymorphisms according to the clinical phenotype of asthma or rhinitis, no relevant associations were found (table 3). however, the analysis according to specific ole e 2 and ole e 10 sensitizations showed several relevant results which are summarized in table 4. firstly, the study of 2 polymorphisms of il10 (c-571-a and a-1117 g) in patients with ole e 2 sensitization showed a statistically significant decrease of cc homozygous il10 - 571c > a genotype compared with ole e 2 nonsensitized patients (50% versus 70.5%, p = 0.029, or, 0.41 ; 95% confidence interval, ci, 0.190.82). this protection was higher when patients with asthma and ole e 2 sensitization were compared with ole e 2 nonsensitized patients with asthma (49.4% versus 78.6%, p = 0.008, or, 0.26 ; 95% ci, 0.090.72). this genotype showed intermediate levels of il-10 cytokine (7.77 5.4 pg / ml) compared with the other 2 genotypes (aa homozygous : 5.9 6.1 pg / ml, ca heterozygous : 8.76 5.3 pg / ml). ca heterozygous il10 - 571c > a genotype was increased in patients with asthma and ole e 2 sensitization compared with ole e 2 nonsensitized patients with asthma (45.7% versus 21.4%, p = 0.02, or, 3.08 ; 95% ci, 1.138.4). secondly (table 4), we have found a statistically significant increase of ga heterozygous tnfa-308g > a genotype in ole e 10 sensitized patients compared with olive pollen allergic patients without sensitization to ole e 10 allergen (25.3% versus 11.9%, p = 0.04, or, 2.5 ; 95% ci, 1.026.1). this polymorphism showed intermediate levels of tnf- cytokine (7.77 5.4 pg / ml) compared with the other 2 genotypes (gg homozygous : 7.01 4.8 pg / ml, aa homozygous : 9.3 6.1 pg / ml). sensitization to specific allergens is a complex response controlled by both genetic and environmental factors. preliminary studies reported that the allergograms of olive - allergic patients living in areas with high level of pollen production (such as some regions as andalusia in spain) are notably different from those obtained in areas of low - level exposure (e.g., madrid in the central region of the country). besides, the level of each allergenic protein in the pollen grain could be a second parameter to be taken into consideration. in fact, a great variability in the allergen composition of o. europaea pollen has been described. the reasons behind this variability are unknown, but they could be due to the existence of several genetic strains, climatic conditions, and specific culture techniques. previous works showed how, in areas with high levels of antigenic load, olive pollen allergic patients were sensitized to allergens that are minor allergens (frequency of recognition lower than 50%) in areas with low antigenic load [21, 22 ]. this sensitization (mainly related to ole e 2 and ole e 10) was associated with a worse clinical prognosis, with a very high presence of asthma and more days of symptomatology. this population was analyzed for inflammatory cytokine polymorphisms (il-13, il4ra, il5, and2adr genes) finding some relevant associations, mainly related to risk factor for olive pollen allergic sensitization. very recently we demonstrated how several immuneregulatory elements are decreased (tgf- and foxp3) in olive pollen allergic patients exposed to extremely high olive pollen antigenic load.. with these previous results, the aim of this work was to determine whether some of the genes previously associated with asthma and immune regulation are important in these specific sensitizations. to do so, we decided to analyze the relationship between 6 genetic polymorphisms of tnfa (g-308a, c-857 t, and c-1031 t) as a proinflammatory gene and il-10 (c-571-a and a-117 g) and tgfb (c-509 t) as being related to regulatory response and specific sensitization to o. europaea pollen in a well - characterized spanish population of patients with olive pollen allergy and a high prevalence of asthma (74.7%). in spite of the small size of our control population firstly, we have shown that the ct genotype of tgfb c-509 t was the only polymorphism (of the 6 analyzed) associated with the genetic regulation of o. europaea allergy (table 3). tgf- is a multifactorial cytokine that plays key roles in normal cellular processes and diseases, such as t - cell activation and proliferation, and may be essential in modulation of allergic airway inflammation and airway remodeling. the tgf- gene is located on chromosome 19q and there are a number of polymorphisms within this gene that are believed to have a role in tgf- expression. tgfb (c-509 t) is presented within a proximal negative regulatory region, and the t allele has been associated with higher tgf-1 plasma levels. due to the inconclusive results on the association of tgf- polymorphisms and asthma, 3 years ago, a meta - analysis was reported studying the role of tgf- and asthma, based on 16-case control sets. the authors concluded that the c-509 t polymorphism (carriers of the t allele) could be a risk factor for asthma, mainly in the asian population and adults. our results are in agreement with the association of tt homozygous and the highest levels of soluble tgf-, but this genotype was infrequent in our population. however, the heterozygous ct genotype, which showed the lowest levels of tgf-, was a risk factor for olive pollen allergy in our population. these data support our previous results in which we reported a tgf- decrease in the sera of olive pollen allergic patients, in an independent cohort of subjects, selected from the same area. all of these results reinforce our previous idea that olive pollen allergic patients have a decreased tgf- dependent regulatory response, thereby pointing to the importance of evaluating, when feasible, the combination of levels and cytokine polymorphisms. according to ole e 2 and ole e 10 specific sensitizations firstly, the cc homozygous il10 - 571c > a genotype could be a protective factor for ole e 2 sensitization and mainly for patients with asthma and ole e 2 sensitization compared with asthmatic - patients nonsensitized to ole e 2. this polymorphism showed intermediate levels of il-10 cytokine (7.77 5.4 pg / ml) compared with the other 2 polymorphisms (aa homozygous : 5.9 6.1 pg / ml, ca heterozygous : 8.76 5.3 pg / ml). in contrast, the ca heterozygous il10 - 571c > a genotype was increased in patients with asthma and ole e 2 sensitization compared with ole e 2 nonsensitized patients with asthma (45.7% versus 21.4%, p = 0.02, or, 3.08 ; 95% ci, 1.138.4). a recent meta - analysis suggested that il-10 promoter polymorphisms were associated with asthma risk. this work revealed significant associations between 1082a / g and 592a / c polymorphisms and asthma. however, there was no significant association between 819t / c polymorphism and asthma risk. other studies showed that a polymorphism at the 592 position of il-10 is associated with its regulation of expression and recently the association of this polymorphism and immune - related diseases has been studied including type 2 diabetes with and without nephropathy, multiple sclerosis, and asthma. secondly, we have found a statistically significant increase of the ga heterozygous tnfa-308g > a genotype in ole e 10 sensitized patients compared with olive pollen allergic patients without sensitization to the ole e 10 allergen (25.3% versus 11.9%, p = 0.04, or, 2.5 ; 95%, ci, 1.026.1) (table 4). this genotype showed intermediate levels of the tnf- cytokine (7.77 5.4 pg / ml) compared with the other 2 genotypes (gg homozygous : 7.01 4.8 pg / ml, aa homozygous : 9.3 6.1 pg / ml). the 308g / a polymorphism in the tnf- gene has been extensively investigated for its association with asthma ; however, the results of different studies have been inconsistent. two years ago a meta - analysis was carried out to analyze the association between the 308g / a polymorphism of the tnf- gene and asthma risk. the results suggested that the tnf- 308g / a polymorphism contributes to susceptibility to asthma and, specifically, significantly elevated risks of asthma were associated with a allele carriers in the atopic population but not in the nonatopic population. more recently, it has been described that the genetic polymorphisms of tgf-1 and tnf- are associated with asthma. this same study also described tgf-1 as being a modulator of atopy, and both tgf-1 and tnf- were found to be elements that modulate clinical severity and airway obstruction in an additive manner. overall, our results suggest a role of tgf-1 in olive pollen sensitization and tnf- and il-10 genotypes in the asthma induced by specific olive pollen allergens. combined analysis of multiple genetic polymorphisms with different allergic phenotypes could be a useful tool for identifying profiles of risk or prevention of these disorders. | sensitization to specific olive pollen - allergens (ole e 2 and 10) has been correlated with a clinical pattern of asthma. this study analyzes the association between several polymorphims of tnfa (g-308a, c-857 t, and c-1031 t), il10 (c-571a and a-1117 g), and tgfb (c-509-t) and these sensitizations. these polymorphisms were genotyped by allelic discrimination, in olive pollen - allergic patients (phenotyped for specific ole e 2 and 10 sensitizations) and healthy controls. levels of serum - soluble cytokines were correlated with specific genotypes and clinical phenotypes. the results showed that heterozygous tgfb c-509 t genotype, besides having the lowest sera tgf- levels, was significantly increased in olive pollen - allergic patients compared with controls. according specific sensitizations, cc genotype of il10 c-571a could be a protective factor for ole e 2 sensitization and mainly for asthmatic ole e 2 sensitized patients compared with asthmatic non - ole e 2 sensitized patients (or : 0.26, p = 0.008). in contrast, heterozygous ca genotype was increased in ole e 2 asthmatic subjects compared to asthmatic non - ole e 2 sensitized patients. lastly, heterozygous tnfa g-308a genotype was associated with ole e 10 sensitization (or : 2.5, p = 0.04). in conclusion, these results suggest a role of tgf-1 in olive - pollen sensitization and tnf- and il-10 genotypes in the asthma induced by specific olive - pollen allergens. |
the eye, like the brain, implanted uterus, and testis, is one of the body 's immune privilege sites. thus, it presents evolutionary adaptation designed to protect itself from blinding influences of immunologic inflammation. specifically, intraocular structures and the cornea have immune privilege, but the extraocular organs and tissues that are also commonly referred to as the eye do not. however, this immune privilege is not always sufficient ; if its natural protective mechanism fails or is overwhelmed, the eye becomes susceptible to uveitis, an intraocular inflammatory disorder that involves a wide variety of underlying etiologies. uveitis is the swelling and irritation of the uvea, the pigmented layer of the eye that lies beneath the sclera and cornea which comprises the iris, choroid, and ciliary body. uveitis may also affect adjacent ocular structures, such as the retina, vitreous, and optic nerve. grape ; a peeled blue grape has a bluish vein structure that resembles the middle, vascular layer of the eye, this being the uvea. anteriorly, the iris controls pupil diameter and size and, therefore, the amount of light that reaches the retina. the ciliary body, a circular band of muscle connected to and seated immediately behind the iris, produces aqueous humor and controls lens shape. specifically, the ciliary muscle, the circular muscle in the ciliary body, controls accommodation by relaxing or contracting zonules to enable the lens to adjust shape in order to focus. lastly, the choroid is a highly vascular coat that extends from the optic nerve to the ora serrata and contains melanocytes, fibroblasts, macrophages, mast cells, and plasma cells. anatomically speaking, the current international uveitis study group classifies it according to the primary anatomical location of inflammation [2, 3 ] : anterior uveitis (anterior chamber), intermediate uveitis (vitreous), and posterior uveitis (choroidea and retina) ; panuveitis (anterior chamber, vitreous, choroidea, and retina). uveitis may also be classified according to principal pathologic features : granulomatous uveitis, characterized by blurred vision, mild pain, eye tearing, and mild sensitivity to light ; nongranulomatous uveitis, with acute onset, pain, and intense sensitivity to light and a better recovery rate than granulomatous uveitis. in clinical terms, uveitis has been classified by the international uveitis study group as infectious (bacteria, viral, fungal, parasitic, etc.), noninfectious (known or unknown systemic association), and masquerade (group of eye diseases that mimic chronic intraocular inflammation). in developed countries, uveitis affects about 200 per 100 000 persons in the general population. the average annual incidence of uveitis has been reported as nearly 20 per 100 000 and peaks for the 2050-year - old age group. the total population prevalence of uveitis varies geographically : 38 per 100 000 in france, 6876.6 per 100 000 in finland, and around 120 per 100 000 in the united states. it is estimated to be 470 per 100 000 in india and 620 per 100 000 in taiwan. more than half of all patients with uveitis develop complications that are related to the disease, and up to 35% of patients suffer severe visual impairment. it can cause devastating visual loss, is the fifth commonest cause of visual loss in the developed world, and accounts for about 1015% of cases of total blindness and up to 20% of legal blindness [10, 11 ]. during inflammation processes and in the eye 's innate immune response, monocytes and macrophages are critical regulators and effectors that work as the immediate and first arm of the immune system. classified all highly phagocytic mononuclear cells and their precursors as what they labeled the mononuclear phagocytic system. they designated tissue macrophages, circulating monocytes, promonocytes, and their precursor cells in bone marrow as mononuclear phagocytes. therefore, the mononuclear phagocytic system is generated from the hematopoietic stem cells located in bone marrow. monocytes are a subset of circulating leukocytes that are released into circulation which seed tissues throughout the body within a few days. they also reach the spleen, which serves as a storage reservoir for immature monocytes. monocytes can further differentiate into a collection of tissue macrophages and dendritic cells (dcs), probably according to the inflammatory milieu and pathogen - associated pattern recognition receptors. thus, when monocytes leave blood vessels and extravasate through the endothelium, they differentiate into macrophages or dcs. some usual settings of tissue macrophages include skin, connective tissue, perivascular connective tissue, and lymph nodes. in the eye, the retina presents microglia, populations of myeloid - derived cells, principally macrophages, which are anatomically situated within the glial limitans of the inner retina vessels and throughout the parenchyma of the retina [13, 14 ]. so microglia express various macrophage - associated markers like cd14, cd11b, and egf - like module - containing mucin - like hormone receptor - like 1 (emr1 ; also known as f4/80 in mice). there is still some controversy as to whether the resident microglia in the retina are replaced by in situ proliferation and/or recruitment of myeloid cells from the bloodstream. thus, some groups using egfp - transgenic mice and cx3cr1 mice have shown a constant turnover of resident retinal microglia by replenishment from bone marrow - derived myeloid cells. they have also found that bone marrow - derived monocyte precursor cells are able to completely replace the retinal myeloid cell population within 6 months via migration over the blood - retinal barrier [1619 ]. however, other authors have proposed that bone marrow - derived precursors only play a minor role in uninjured retina microglia maintenance and discovered that engraftment of bone marrow - derived microglia in the retina takes place almost only with retinal damage [17, 20 ]. the middle layer of the wall of the eye, the uvea, also presents networks of macrophages and dcs that participate in maintaining ocular homeostasis [21, 22 ]. moreover, corneal immune privilege has been partly attributed to the lack of functional antigen - presenting cells (apcs) within the cornea. it has been detected that dcs reside in the corneal epithelium, monocyte - lineage cells in the corneal stroma, and macrophages in the lamina propria of the conjunctiva. macrophage - like cells in the substantia propria of the conjunctiva perform a relevant phagocytic function on the outer ocular surface part, dcs in the corneal epithelium quickly respond to foreign antigens, and monocyte - lineage cells in the corneal stroma work as dc and macrophage precursors and also possess phagocytic activity. the lamina propria is rich in bone marrow - derived cells that form a mucosal immune system of different kinds of blood vessels. generally, mucosa - associated lymphoid tissue (malt) represents a part of the immune system located on mucosal surfaces and consists of clusters (follicles) of lymphatic cells situated within and beneath the epithelium of a mucosal surface. the cellular components of malt include b - cells, cd4 and cd8 t - cells, antigen - presenting dendritic cells, macrophages, and, occasionally, mast cells and eosinophils in the interfollicular region. in the eye, its most well - known representatives are conjunctiva - associated lymphoid tissue (calt) and lacrimal duct - associated lymphoid tissue (ldalt). like resident phagocytic cells, macrophages are armed with a wide array of surface receptors that are specific for pathogens or antigens, which render them efficient to play their role in steady - state tissue homeostasis : clearance of apoptotic cells, phagocytosis of foreign material, and production / secretion of growth factors and proinflammatory cytokines. microglial cells also present additional roles in retinal growth by phagocytosing the pyknotic cells generated in the developing retina and by contributing in retinal neurogenesis and blood vessel formation [3134 ]. in both phenotype and function terms, macrophages have enormous heterogeneity, which shows the specialization of tissue - resident macrophages in microenvironments. the m1/m2 macrophage activation paradigm has provided a useful framework, but a more comprehensive classification is evidently required. in fact, it seems that macrophages do not form stable subsets. rather than subsets of macrophages, we find pathways that interrelate to form complex, and even mixed, phenotypes [3537 ]. classical dcs are apcs with the unique ability to induce primary immune responses, armed with strong phagocytic activity as immature cells and good cytokine - producing capacity as mature cells. hence, dcs not only are crucial for inducing primary immune responses, but also may be relevant for generating immunological tolerance and for the regulation of the t - cell - mediated immune response type [18, 38 ]. thus, during human uveitis, the aqueous humor suppression of dcs helps maintain immune regulation in the eye. accordingly, the eye has its own mechanism to protect itself from inflammation called immune privilege. immune privilege is meant to be an adaptation to restrict immune - mediated inflammatory processes that might inflict injury to eye cells with limited regeneration capacity. basically, it consists in active tolerance to foreign antigens through different mechanisms that may lastly induce apoptosis, promote the production of anti - inflammatory cytokines, and mediate the activation of antigen - specific regulatory immunity. multiple anatomical, structural, physiological, and immunoregulatory processes converge to maintain this so - called immune privilege. first, the carefully sealed blood - ocular barriers (the blood - aqueous barrier and the blood - retinal barrier) limit the passage of inflammatory cells and molecules from blood into the eye. second, other mechanisms promote the eye 's immune privilege, such as lack of lymphatics, intraocular immune modulators, induction of t regulatory cells (tregs), and other properties that maintain tissue integrity. so while some periocular tissues contain lymphatics (e.g., conjunctiva and the episclera), the eye 's intraocular compartment lacks traditional lymphatics. immune effectors in the blood stream, including sensitized t - cells and antibodies, are mostly excluded from the eye by potent blood - ocular barriers. the conjunctiva consists of an epithelium and an underlying free connective tissue named the lamina propria. epithelial histology is stratified nonsquamous and comprises two to three cell coats that display a typically cuboidal morphology. as a mucosa, it is ensured by the mucosal immune system (innate and adaptive) present in the tissue and tear film. the immune system of the ocular surface forms an eye - associated lymphoid tissue (ealt). mucosa and therefore ealt have certain characteristics that differentiate them from the central immune system and result in mechanisms such as immunological ignorance, tolerance, or an immunosuppressive local microenvironment, all of which favor nonreactivity and anti - inflammatory immunological responses. the interaction of all these mechanisms also results in the immune privilege of the ocular surface. the inner blood - retinal barrier is set within the retinal parenchyma and consists of a nonfenestrated endothelium that is interconnected by tight junctions and covered by foot branches of astrocytes. nevertheless, the outer blood - retinal barrier facilitates intraocular migration by leukocytes and is equipped with immunoregulatory skewing capacities. this barrier is set exteriorly to the neural retina and consists of tight junction - interconnected retinal - pigmented epithelial cells and fenestrated choriocapillaris. finally, the blood - aqueous barrier is formed by the nonpigmented ciliary epithelium of the ciliary body and the vascular fenestrated endothelium of iris vessels. this barrier is permeable for cellular migration and leukocytes may access aqueous humor through its structure. the placement of a foreign antigen into the eye elicits the generation of peripheral tolerance, which is maintained by antigen - specific tregs. specifically, the placement of alloantigens into the anterior chamber induces a form of immune tolerance known as anterior chamber - associated immune deviation (acaid), which induces antigen - specific cd8 tregs and contributes to the eye 's immune privilege by downregulating immune responses. treg cells prevent autoimmune diseases by maintaining self - tolerance and suppress pathogen - induced immunopathology. along with the induction of treg cells hence, systemic, antigen - specific, active immunologic tolerance is mediated by specific class i major histocompatibility complex- (mhc i-) restricted tregs, which modulate inflammatory responses within the eye and form part of the immunoregulatory process. acaid is a crucial mechanism for maintaining the eye 's immune privilege. in an initial ocular phase, a foreign antigen placed in the anterior chamber is captured by indigenous apcs. in the eye, professional apcs, such as dcs, macrophages, and b - cells, today, we know that the process is mediated by macrophages (f4/80 class ii cells) that work as professional apcs, lie in the eye 's anterior chamber, and are responsible for transporting the injected antigen to the spleen. in the spleen, eye - derived cd1-apcs come to rest in the marginal zone and secrete transforming growth factor- (tgf-) and macrophage inflammatory protein 2 (mip2) by chemoattracting natural killer t- (nkt-) cells to the site. so ocular apcs interact with invariant b - cells and natural killer t - cells to generate multicellular clusters, which create immunomodulatory microenvironments in the splenic marginal zone which are rich in active tgf-, interleukin 10 (il10), and chemokine (c - c motif) ligand 5 (ccl5 or rantes). the process culminates in the elicitation of systemic regulatory immunity through the induction of treg cells [41, 4648 ]. thus, the immune response to antigens ' contact results in an immunosuppressive environment, which includes the generation of treg cells by aqueous humor, ifn- production, and inhibition of t - cell proliferation. throughout this process, in fact, the macrophages treated with tgf-2 and antigen are highly tolerogenic in vivo and induce antigen - specific and long - lasting tolerance in mice via the induction of treg cells. it is noteworthy that suppressor immunity in the eye is, therefore, expressed by the induction of treg cells which, as regulators, suppress the induction and expression of t - helper cell type 1 (th1) and th2 immune expression systems. other mechanisms that support the eye 's immune privilege include absence of mhc class ii professional antigen - presenting cells and the presence of immune modulators, such as tgf-, complement decay accelerating factor (cd55 or daf), cluster of differentiation 200 (cd200), cluster of differentiation 46 (cd46), macrophage migratory inhibition factor (mif), and pd - l1 [41, 51 ]. recently, hsu. showed that acaid induced in vivo by the intravenous inoculation of ex vivo generated retinal antigen - pulsed tolerogenic antigen - presenting cells (tolapc) in the presence of experimental autoimmune uveitis - inciting antigen (interphotoreceptor retinoid - binding protein, irbp) or retinal antigen extract was able to modulate the clinical symptoms and inflammatory cytokines of irbp - induced experimental autoimmune uveitis in mice. these results raise the possibility that the clinical symptoms of human uveitis might be relieved by a therapy that uses a target tissue extract instead of a specific antigen. in any case, the immune privilege is a complex dynamic phenomenon that is the total sum of the processes and molecules which prevent the induction and expression of both innate and adaptive immunity. however, immune privilege incurs a significant risk ; if the eye 's privileged status is compromised, the succeeding disease can prove devastating. from sentinel and clearance functions, resident macrophages in tissues may induce acute inflammatory and vascular changes through their close association with the microvasculature. acute inflammation is a process initiated by those cells that were previously present in affected tissues, mainly resident macrophages and dendritic cells. these cells are able to recognize the molecules that are linked to groups of the pathogens, pathogen - associated molecular patterns (pamps), or damage - associated molecular patterns (damps) released from injured cells through the receptors contained on their surface or within these cells, namely, pattern recognition receptors (prrs), for example, phagocytic c - type lectin receptors, scavenger receptors, nucleotide - binding oligomerization domain - like receptors (nlrs), and transmembrane signaling toll - like receptors (tlrs) [53, 54 ]. when prrs bind pamps, they trigger an immediate cellular or molecular response. firstly, macrophages engulf and kill invading microorganisms and present an important phagocytic role as first defense in innate immunity but also have pathogens and infected cells that are targeted by an adaptive immune response. macrophages release different toxic products that help phagocyte microorganisms, which include antimicrobial peptides, reactive nitrogen species (no), and reactive oxygen species (ros), such as superoxide anion (o2) and hydrogen peroxide (h2o2) [5557 ]. in the early phase of the uveoretinitis, concomitantly with the generation of oxygen metabolites, peroxidation of retinal membrane lipids takes place [58, 59 ]. macrophages also support initial inflammation by secreting signaling proteins (cytokines and chemokines) that activate other immune system cells and recruit them in an immune response. thus, some nlrs also recognize nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes, which link the sensing of microbial products and metabolic stress to the proteolytic activation of proinflammatory cytokines il-1 and il-18. phagocytic myeloid cells, particularly dcs, also utilize phagocytosis to direct antigens to both compartments mhc i and mhc ii [23, 63 ]. hence, phagocytosis plays a dual role as an effector of innate immunity and an inductor of acquired immunity. nonactivated inflammatory monocytes and inflammatory dcs work like apcs, but they suppress t - cells through nitric oxide production when activated. suppressive inflammatory monocytes are induced by ifn-, gm - csf, tnf-, and cd154, which derive from activated t - cells during their interaction. these authors demonstrated that the myeloid cells isolated from the cns in different disease stages were able to either activate or suppress t - cells. the term macrophage activation (classical activation) was introduced by mackaness in the 1960s in an infection environment, was then linked with th1 responses and ifn production, and was later extended to cytotoxic and antitumoral properties. therefore, with different pathological stimuli, for example, injury or damage, microbial attack, or activated lymphocytes, macrophages undergo reprogramming, which gives rise to diverse macrophage phenotypes, broadly classified as the m1 proinflammatory (classically activated) phenotype and an m2 anti - inflammatory (alternatively activated) one, which are two extremes of a range of macrophage functional states [3537 ]. polarized macrophages vary in terms of receptor expression, effector function, and cytokine and chemokine production. thus, when mirroring the th1-th2 paradigm, they are considered to be m1 macrophages when induced by microbial products or proinflammatory cytokines, such as ifn, lipopolysaccharide, tnf, gm - csf, or toll - like receptor ligands, and m2 anti - inflammatory macrophages when stimulated by th2 cytokines like il4, il10, il13, il21, il33, or tgf- [66, 6972 ]. eau is an animal model of human endogenous uveitis that is normally induced by several retinal autoantigens. thus, the pathology of eau accurately resembles human uveitic diseases of a recognized autoimmune nature in which patients display immunological responses to retinal antigens (sympathetic ophthalmia, behcet 's disease, and birdshot retinochoroidopathy, among others) [51, 74 ]. traditionally, the eau mice model has been induced with retinol - binding protein- (rbp-) 3, previously known as interphotoreceptor retinoid - binding protein, a major retinal protein that shuffles vitamin a derivatives between photoreceptor cells and the retinal pigment epithelium. rbp-3 is emulsified in complete freund 's adjuvant, which consists in a suspension of tuberculosis bacteria in mineral oil, which is crucial for disease induction in both mice and rats. humanized model of eau, which is induced in hla class ii transgenic mice. thus, modified transgenic mice for any one of a number of hla class ii alleles develop eau after immunization with retinal arrestin [75, 76 ]. different mouse models of spontaneous disease have also been achieved such as in rbp-3 t - cell receptor transgenic (r161h) mice, also in mice deficient in the aire (autoimmune regulator) gene, and in hlaa29 transgenic mice or by neoantigens (hen egg lysozyme, hel). clinical disease in eau hence, numerous studies have identified macrophages that play a crucial role in eau, mostly in relation to early stages : during the induction and effector phase of the disease [8183 ]. so certain evidence shows distinct roles for macrophages in different stages during eau evolution and in relation to m1 classical activated macrophages, promoted in a tnf - dependent manner by the ifn gamma release from the th1 cd4 t - cell infiltrate. in fact, khera. showed that a soluble form of tnf is required in eau for inflammatory cell infiltration into the target tissue. however, at the tissue site, inhibition of both soluble tnf and transmembrane tnf is required to inhibit macrophage activation and to protect from tissue damage. in this context, tissue damage is mediated by the further release of proinflammatory cytokines (il1b, il6, and tnf), ros, and nitric oxide [84, 86 ]. hence, ifn-mediated macrophage activation, which depends on tnf- and functional tnfr1, results in high levels of nitric oxide, tnf-, and il-6 and thus produces lipid peroxidation and damages surrounding cells [87, 88 ]. in a recent study, london. showed that ccr2cx3cr1ly6c monocyte - derived macrophages are recruited early during the disease process and are involved in the induction of eau pathology by displaying the typical proinflammatory phenotype. early inhibition of this infiltration has been seen to prevent eau, whereas its inhibition after the disease peaked resulted in fewer foxp3 treg cells in the retina and also in worse disease outcome. some studies have also demonstrated the presence of macrophages in the resolution phase, with infiltration of myeloid cells showing suppressive properties to t - cell activation and proliferation which, in a sense, regulates the autoimmune response through both nitric oxide activation - induced cell death and the elimination of t - cells in the retina through prostaglandin - mediated pathways. activated macrophages release tnf, and the expression of one of its receptors, tnfr1, is necessary for normal organ - specific autoimmunity development and is a critical key for developing the macrophages that control t - cell proliferation. pge2 is required for myeloid - derived suppressed cells maturation in vivo and can modulate the function of dendritic cells, such as apcs [90, 91 ]. some recent reports in the experimental autoimmune encephalomyelitis model have revealed that invariant nkt cell activation results in the differentiation of monocytes in an m2 phenotype and has a positive impact on disease development. similarly, london. found a subset of macrophages (cx3cr1) with immune - resolving activity in eau that enabled the disease to reach a state of equilibrium instead of relapsing. these authors also detected an anti - inflammatory mediator, il10, expressed by the infiltrating macrophage. il10 has been shown to play a protective role in eau and is an important factor in the development and function of tregs [94, 95 ]. acute anterior uveitis (aau) is the commonest form of uveitis as it represents up to 92% of all uveitis cases [96, 97 ]. aau is characterized by the breakdown of the blood - aqueous barrier and acute inflammation of the iris and ciliary body, by showing the upregulation of cell adhesion molecules on the uveal vasculature, as well as the aqueous humor expression of proinflammatory cytokines (e.g., tnf and ifn) and chemokines that selectively recruit and activate inflammatory cells (neutrophils, monocytes, and lymphocytes) into the uvea and anterior chamber. since rosenbaum. described how systemic immunization with endotoxin (lipopolysaccharides) from gram - negative bacteria produces bilateral acute anterior uveitis in rats in 1980, many clinical and experimental data have shown that any kind of gram - negative bacteria or their lipopolysaccharides (lps) play a key role in aau development. indeed, clinical and laboratory research has verified that gram - negative bacteria species, such as klebsiella, salmonella, yersinia, and shigella, can trigger aau. hence, endotoxin - induced uveitis (eiu) is an acute form of uveitis that is induced by injecting a sublethal dose of lps, a component of the cell walls of gram - negative bacteria, into experimental animals, including rats, mice, and rabbits. therefore, it is an advantageous human aau model that is not autoimmune that has acted as a valuable model for ocular acute inflammatory processes driven by innate immune mechanisms and their effects on tissue. eiu is marked by both vasodilatation of the iris and vascular changes in the ciliary body, accompanied by increased vascular permeability and a breakdown of the blood - aqueous barrier. in the eye 's anterior segment, it involves the activation of endothelial cells and resident monocytes - macrophages as initiators of inflammatory response, following neutrophil and mononuclear cells infiltration, to generate multiple proinflammatory mediators, such as cellular adhesion molecules, cytokines and chemokines, ros production, and tissue damage [100, 101 ]. inflammation ensues 4 h after lps injection, peaks after 2448 h, and declines 96 h after disease induction. monocytes begin to marginate in iris vessels at 2 h after injection ; after 4 h, they form perivascular cuffs and are broadly distributed among resident macrophages after almost 24 h. therefore, monocytes and macrophages respond directly to lps as an initial source of cytokines and chemokines. eiu is usually considered an inflammation of the anterior uvea. however, posterior segment findings have also been reported, including vitritis, vitreous hemorrhage, retinal vasculitis, inflammatory cell infiltration of the retina, and choroiditis. thus, systemic lps injection has been followed by the massive entry of macrophages into the retina, although major histocompatibility class ii - positive cells have not been found after lps injection. therefore, eiu alters the expressions of kir4.1 and aqp4 in the retina, which indicates a disturbance of water and potassium transport in the retina that contributes to retinal edema during ocular inflammation. choroid is also severely inflamed after systemic lps administration, with a massive influx of ed1-positive macrophages into the area below the retinal pigment epithelium. tlrs are a family of phylogenetically conserved prrs of the innate immune system that recognize unique pamps. indeed, a marked tlr4 protein expression pattern has been observed in the human uvea. tlr4 is expressed in macrophages as the main specific lps recognition and cellular activation signaling receptor, which may play a relevant role in starting uveitis. tlr4 is unique among tlrs as it signals through two well - characterized adaptor molecules : myd88 and trif. however, eiu is primarily dependent on both radiation - resistant cells and myd88, but not on trif. the tlr4 signaling pathway induces nfb activation and, consequently, the synthesis and release of proinflammatory mediators such as tnf-, cytokines, chemokines, adhesion molecules, ros, and reactive nitrogen radicals. chen. observed a preferential expression of tlr4 in tissue macrophages within the iris and ciliary body in eiu and proposed a novel mechanism for the initiating factors and immunopathogenesis of uveitis. in fact, inducing acute anterior uveitis in tlr4 gene - deficient mice in an eiu model was not possible. yang. showed that tlr4 signal activation can lead to the cascading expansion effect of cytokines during eiu by analyzing cytokine changes in the supernatant of cultured macrophages in diverse mice groups after lps stimulation. lps also functions as an antagonist of peroxisome proliferator - activated receptor alpha (ppar), a nuclear transcription factor with protective effects associated with the modulation of tlr4 signaling pathways in eiu. a recent study by ekici. has shown that a tlr4 antagonist treatment in the eiu rat model significantly lowered the levels of tnf, mda, and nfb. the global result was less inflammatory damage in terms of serum and retinochoroidal tissue parameters. finally, in recent studies conducted into eiu, m1 and m2 macrophage polarization has been reported [117, 118 ]. in vitro, lps induces a typical m1 profile through the recognition of lps by tlr4 [119, 120 ]. signaling mechanisms include nf-b activation, lps - induced tnf- factor upregulation, and pi3k pathway stimulation. during an inflammation resolution process of eiu mediated by lipid - derived protein resolvin d1 (rvd1), rossi. found that lps- and rvd1-treated rats reduced the presence of m1 macrophages and increased protective m2 macrophages in ocular tissues. resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. in the last few years, experimental animal models have enabled us to better understand the leading role of macrophages in eye inflammation processes, counting macrophage polarization and the significant role of tlr4. this knowledge should guide advantageous iterative research, including strategic in vitro and in vivo studies, to establish mechanisms and possible therapeutic targets for human uveitis resolution. | resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. they are major effectors of tissue damage in uveitis and are also considered to be potent antigen - presenting cells. in the last few years, experimental animal models of uveitis have enabled us to enhance our understanding of the leading role of macrophages in eye inflammation processes, including macrophage polarization in experimental autoimmune uveoretinitis and the major role of toll - like receptor 4 in endotoxin - induced uveitis. this improved knowledge should guide advantageous iterative research to establish mechanisms and possible therapeutic targets for human uveitis resolution. |
chronic kidney disease (ckd) is a major public health problem worldwide, and it may lead to end - stage renal disease (esrd). esrd is defined as an irreversible reduction in kidney function, and the high mortality rate is one of the main challenges associated with the treatment of these patients (1). according to recent reports, the total number of patients with esrd has been increasing dramatically (2). renal transplantation is the preferred treatment modality for renal replacement therapy in patients with esrd due to the high rate of patient survival, improved quality of life, and low health care costs. according to a report by the management center for transplantation and special diseases of iran, the frequency of patients with esrd undergoing renal replacement therapy (rrt) was 32,686 in 2007 (prevalence of 435.8 per million population (pmp)). this number is very high when compared to the frequency in both 1997 and 2000, when the prevalence of esrd was 137 pmp and 238 pmp, respectively. the incidence of patients with esrd also seems to have increased from 13.82 pmp in 1997 to 49.9 pmp in 2000 and then 63.8 pmp in 2006 (3). patient survival has significantly improved over the last three decades. however, despite significant efforts being made to improve the survival of renal grafts, many patients still experience graft failure. the rate of five - year survival of kidney allografts was estimated to be 82.5% in iran in 2011 (4). graft failure is a major clinical event, and it is defined as a return to dialysis, or death with a functioning graft (5). unfortunately, the main determinants of both the patient s and the graft s survival are not yet completely understood (6, 7). in medical research, it is common to observe a time - to - event outcome, together with longitudinal measurements of a disease marker. since it is essential to monitor the disease progression of patients who have undergone renal transplantation, the continuous assessment of kidney function over time is important (8, 9). for renal transplantation patients, the serum creatinine level is the simplest biomarker that is routinely measured to monitor the disease progression of a kidney transplant recipient. once a patient experiences graft failure, measurements of the serum creatinine level will not be recorded and the patients will no longer be monitored for kidney function, which results in missing data. the longitudinal serum creatinine level and the time to graft failure are typically correlated, with both types of data being associated through unobserved random effects. separate analyses of longitudinal measurements and survival data may lead to biased estimates (10 - 12). the joint modeling of survival data and longitudinal measurements takes into account the dependence between both processes, and it can handle non - ignorable missing data. more accurate parameter estimates and efficient inferences concerning the effect of the covariates on the longitudinal and survival processes can therefore be obtained (13, 14). the existing methods for the joint modeling of longitudinal outcomes and time - to - event data can be highly influenced by the presence of outlying observations in the longitudinal data (i.e., serum creatinine level). robust joint modeling can be used to investigate the relationship between both the serum creatinine levels and the time to graft failure in the presence of outliers in the serum creatinine values (15 - 17). the aim of the current study is to investigate the etiological role of recipient characteristics in serum creatinine changes within the follow - up period and in relation to the graft failure risk, as well as to evaluate whether or not the serum creatinine level represents an indicator of graft failure following renal transplantation. this retrospective cohort study included 413 patients with esrd who underwent renal transplantation at the baqiyatallah transplant center, baqiyatallah hospital, tehran, iran, between april 2005 and december 2008. the study parameters were retrieved from a computerized database of transplant patients that includes the recipient s age, gender, bmi, blood group, history of diabetes, history of dialysis therapy prior to transplantation, and donor type. the primary outcomes of the study were the determination of the serum creatinine levels at each attendance and the time to graft failure. the serum creatinine levels were recorded at several time points (before renal transplantation, 15 days after transplantation, and one, three, six, 12, and 24 months after renal transplantation). in many medical studies, survival data and longitudinal biomarkers, the serum creatinine level was measured intermittently over time for each recipient, while the time to graft failure was another outcome of interest., separate analyses of survival and longitudinal outcomes may lead to biased results. using the joint modeling approach, all information from the survival and longitudinal processes is included simultaneously in the model so as to provide valid and efficient estimates (14). a joint model can link two processes by un - observed random effects through the use of a shared parameter model (18). within the joint modeling framework, the linear mixed effects model was applied to model the longitudinal serum creatinine levels, while the cox proportional hazard model was used to model the time to graft failure. in the current data, there were outlying observations in the serum creatinine levels, and the existing methods for joint modeling can be highly influenced by outliers in the longitudinal data. to overcome this problem, a joint model is proposed that is robust against outlying longitudinal measurements due to assuming a t - distributed measurement error in the linear mixed effects sub - model. the bayesian estimation method was applied to estimate the model parameters. in this study, bayesian parameter estimates, the posterior mean (standard deviation), and a 95% credible interval are reported. according to the bayesian approach, the parameter estimates are significant when the 95% credible interval does not contain a zero. the proposed robust joint model was implemented using winbugs 1.4.3 statistical software (19). in many medical studies, survival data and longitudinal biomarkers are collected together. in this study, the serum creatinine level was measured intermittently over time for each recipient, while the time to graft failure was another outcome of interest., separate analyses of survival and longitudinal outcomes may lead to biased results. using the joint modeling approach, all information from the survival and longitudinal processes is included simultaneously in the model so as to provide valid and efficient estimates (14). a joint model can link two processes by un - observed random effects through the use of a shared parameter model (18). within the joint modeling framework, the linear mixed effects model was applied to model the longitudinal serum creatinine levels, while the cox proportional hazard model was used to model the time to graft failure. in the current data, there were outlying observations in the serum creatinine levels, and the existing methods for joint modeling can be highly influenced by outliers in the longitudinal data. to overcome this problem, a joint model is proposed that is robust against outlying longitudinal measurements due to assuming a t - distributed measurement error in the linear mixed effects sub - model. the bayesian estimation method was applied to estimate the model parameters. in this study, bayesian parameter estimates, the posterior mean (standard deviation), and a 95% credible interval are reported. according to the bayesian approach, the parameter estimates are significant when the 95% credible interval does not contain a zero. the proposed robust joint model was implemented using winbugs 1.4.3 statistical software (19). the results of the robust joint modeling of the serum creatinine levels and the time to graft failure are presented in table 2. (%). according to the results of the survival sub - model, patients who received a living donor kidney had a higher risk of graft failure than patients who received a deceased donor kidney transplant (hr = 1.82 ; 95% hpd : (1.39 to 3)). the time to graft failure was not significantly associated with the recipient s age, gender, history of dialysis prior to transplantation, or history of diabetes (table 2). based on the results of the longitudinal sub - model, the serum creatinine values significantly decreased over time (table 2). the recipient s age was negatively associated with the serum creatinine values (table 2). however, no significant association was found between the serum creatinine levels and the recipient s bmi, gender, or history of dialysis (table 2). in addition, the significant model association parameter revealed a positive association between the serum creatinine levels and graft failure, which means that graft failure is more likely to occur in patients with higher serum creatinine levels (hr = 5.13, p < 0.001). abbreviations : bmi, body mass index ; ci : credible interval ; sd, standard deviation. according to the bayesian approach and the longitudinal sub - model, the parameter estimates are significant when the 95% credible interval does not contain a zero. in the survival sub - model, the credible intervals that do not contain the annual frequency of patients with esrd seems to be increasing at a rate of 7 % - 8% (20). the increasing incidence of esrd patients in iran suggests that it is a significant medical, social, and economic problem (3, 21). the continuous assessment of kidney function over time is performed in order to monitor the disease progression. the progression of renal disease is usually determined by changes in the levels of various markers. in this regard, a decrease in the serum creatinine level indicates an improvement in kidney function over time (22). the current study aimed to investigate the etiological role of recipient characteristics in serum creatinine changes within the follow - up period and in relation to the graft failure risk, as well as to evaluate the association between the serum creatinine level and graft failure following renal transplantation. the current study utilized a new statistical methodology, the robust joint modeling of survival data and longitudinal biomarker measurements, to assess whether changes in the serum creatinine level over time were associated with the time to graft failure following renal transplantation. in the current study, the time to graft failure was not significantly correlated with the recipient s age, gender, history of dialysis prior to transplantation, or history of diabetes. according to the results of this study, the patients appeared to have improved kidney function over time, as evidenced by the negative slope of the serum creatinine level in the longitudinal sub - model. the current study s findings in the longitudinal sub - model regarding time and age are consistent with those of other studies (22). a statistically significant relationship between age and the serum creatinine levels, no significant association was found between the recipient s gender and the serum creatinine values. however, a previous study found that male patients have inferior kidney function when compared to females (22). the main finding of the current study is the direct association between serum creatinine levels and graft failure, which means that graft failure is more likely to occur in patients with higher serum creatinine levels. a one unit increase in the serum creatinine level suggests an increased risk of graft failure of up to 5.13 times. therefore, measuring the serum creatinine levels in order to monitor the outcome of renal transplantation is a very important issue. in general, there is agreement between studies in the nephrology field regarding the role of the serum creatinine level in the likelihood of experiencing graft failure following renal transplantation (24, 25). the main advantages of this study were the investigation of the influential parameters on both the longitudinal serum creatinine levels and the time to graft failure outcomes following renal transplantation, as well as the evaluation of the dependence between the serum creatinine levels and graft failure through the simultaneous joint model. additionally, in the current study the existing methods for joint modeling were modified to produce more efficient estimates of the model parameters in the presence of outlying observations in the serum creatinine levels. only a few prior studies have focused on the factors that influence the serum creatinine levels over time (22). there were some missing values in the records of the serum creatinine levels for some transplantation patients. there were some missing values in the records of the serum creatinine levels for some transplantation patients. | backgroundchronic kidney disease (ckd) is a major public health problem that may lead to end - stage renal disease (esrd). renal transplantation has become the treatment modality of choice for the majority of patients with esrd. it is therefore necessary to monitor the disease progression of patients who have undergone renal transplantation. in order to monitor the disease progression, the continuous assessment of kidney function over time is considered.objectivesthis study aimed to investigate the etiological role of recipient characteristics in serum creatinine changes within the follow - up period and in relation to the graft failure risk, as well as to evaluate whether or not the serum creatinine level represents an indicator of graft failure following renal transplantation.methodsthis retrospective cohort study was conducted at the department of nephrology, baqiyatallah hospital, baqiyatallah university of medical sciences, between april 2005 and december 2008. the study involved 413 renal transplantation patients. the primary outcomes were the determination of the serum creatinine levels at each attendance and the time to graft failure. robust joint modeling of the longitudinal measurements (serum creatinine level) and time - to - event data (time to graft failure) were used for the analysis in the presence of outliers in the serum creatinine levels. the data analysis was implemented in winbugs 1.4.3.resultsthere was a positive association between the serum creatinine level and graft failure (hr = 5.13, p < 0.001). a one unit increase in the serum creatinine level suggests an increased risk of graft failure of up to 5.13 times. the serum creatinine level significantly decreased over time (95% ci : (-1.58, -1.08)). the recipient s age was negatively associated with the serum creatinine level (95% ci : (-0.02, -0.001)).conclusionsgraft failure is more likely to occur in patients with higher serum creatinine levels. |
the optimal treatment technique for anal canal cancer (acc) has traditionally presented a challenge to the radiotherapy community. the highly irregular target volumes associated with acc combined with the presence of numerous organs at risk (oar) within close proximity means that achieving the ideal therapeutic ratio can be problematic.1 traditionally used radiotherapy techniques, such as three - dimensional conformal radiation therapy, can result in severe acute toxicity potentially impacting treatment continuity. these acute and late toxicities included moist skin desquamation, diarrhoea, dysuria, marrow suppression, perineal skin atrophy and fibrosis and femoral neck fractures.16 the impact of these acute toxicities is that some patients may require a treatment break to recover from their toxicities or may not actually complete treatment, potentially leading to a compromise in tumour control.79 it is difficult with traditional techniques to reduce dose to many oar and therefore minimise toxicity. intensity modulated radiotherapy (imrt) allows highly conformal treatment plans to be produced and is well suited for use in acc to minimise oar dose and toxicity whilst still delivering the prescribed dose to the tumour thus enabling the patient to complete the intended treatment without interruption.10,11 the use of imrt in acc is still relatively new in australia. a survey of 16 radiotherapy departments around australia in 2010 showed limited use and experience of imrt in acc.12 one of the major challenges associated with introducing imrt planning for acc is establishing achievable dose planning objectives to facilitate adequate dermatologic, gastrointestinal, genitourinary and bone marrow (bm) sparing whilst maintaining prescribed high doses to the tumour. the aims of the study were to (1) evaluate the ability of plans created during a technology assessment project to meet a defined set of planning objectives and (2) identify factors that may impact on the ability to meet these planning objectives. this information could assist departments inexperienced with imrt for acc in selecting achievable dose planning objectives for use. the data utilised in this investigation were collected from part of the assessment of new radiation oncology treatments and technologies (anrotat) project. this project was undertaken by the trans tasman radiation oncology group (trog) in response to a commission by the australian government department of health and ageing to develop and pilot an evaluation framework of new technologies with a view to providing improved funding for imrt if evidence compiled by the project was compelling.13 the purpose, objectives and specific details of the project are described in the anrotat protocol.12,13 data collection occurred between june 2011 and april 2012. the acc section of the anrotat project consisted of five component studies including credentialing, dosimetry and prospective toxicity and quality of life assessment. the data collected in the imrt dosimetry component of the project have been utilised in this investigation. eligibility criteria included histological confirmation of squamous cell carcinoma, intention to electively irradiate all pelvic nodal groups up to l5-s1 interspace (including mesorectal, presacral, internal iliac, external iliac, ischiorectal fossa, obturator and inguinal groups) and planned for radical chemoradiotherapy. patient ct data sets were excluded if there was evidence of metastatic disease, if they had prior pelvic radiotherapy or surgery (e.g. vaginal hysterectomy) or had a hip prosthesis. the selection comprised a mix of different stages for both male and female patients, all positioned supine, who met the eligibility criteria (table1). stage t1n0 was excluded, as some centres do not routinely electively irradiate the inguinal nodes in this setting. ethics approval was obtained for use of the retrospective data sets for all participating centres. each of the participating centres were allocated three of the 15 data sets, and prepared an imrt plan for each data set. as the purpose of this investigation was to evaluate dose distribution and not to assess variations in contouring, all target volumes and oar structure sets were included with each ct data set. target volume contours were marked and reviewed by two radiation oncologists and were delineated using the guidelines proposed by the australasian gastrointestinal trials group (agitg).14 target volumes provided were planning target volume (ptv) 45 gy (elective volume), ptv54 gy - p (primary volumes with n1, n2 and n3 (n represents node with the 1, 2, 3 representing the number of involved nodes). a 1 cm clinical target volume (ctv) to ptv margin if the ptv contour extended outside the skin, it was cropped to the skin surface. for planning purposes, objective ptv volumes cropped 5 mm from the skin surface were created by the centre for plan optimisation. oar contours provided included bm, bowel, left and right femoral head and necks, external genitalia and bladder.12 the bowel was delineated as a cavity, 15 mm superior to the cranial aspect of the ptv, extending inferiorly to the recto - sigmoid junction based on the study by devisetty and colleagues.12,16 external genitalia included the perineum with the cranial extent at the upper level of the pubic symphysis. all imrt plans were generated using a simultaneous integrated boost technique according to the anrotat protocol.12 the prescription consisted of two dose levels (1) ptv-45 gy receiving 45 gy and (2) ptv-54 gy receiving 54 gy delivered over 30 fractions. dose coverage requirements and dose planning objectives for oar for the anrotat protocol are shown in table2. the primary objective was to achieve target volume coverage followed by the oar dose constraints and planning objectives listed in order from most to least important. these constraints were adapted from the radiation therapy oncology group (rtog) 05 - 29 phase 2 study protocol that assessed imrt in anal cancer with one exception.17 the small bowel constraint was modified to bowel based on data published by devisetty and colleagues.16 this paper provided dose volume correlation with acute bowel toxicity in acc patients undergoing chemoradiation, and hence supported the anrotat project 's health economic analyses. at the commencement of the anrotat project, there was no other relevant literature providing oar dose correlation with acute toxicity in acc radiotherapy. imrt dose planning objectives / constraints dose planning objectives are listed in descending order of priority. dx, dose covering x% of the volume ; vx, volume of organ receiving xgy. centres were directed that effort should be made to achieve the listed dose constraints but were advised that constraints can not always be achieved, and therefore planning objectives were specified listed in order from highest to lowest priority. failure to meet some dose constraints would result in minor or major deviations (table3). these deviations were set by the group to assist in assessing clinical safety and compliance. the only oar that major deviation levels were specified for were the bowel and femoral heads as these were the only two oar with published dose volume toxicity data in acc patients for acute bowel toxicity and femoral neck fractures.16,18 the threshold levels for these structures were based on these studies. plan review definitions of major and minor deviations ptvs, planning target volumes ; dx, dose covering x% of the volume ; vx, volume of organ receiving xgy. all plans were submitted electronically in dicom rt or rtog format for review using the focal treatment planning system (elekta ab, stockholm, sweden).19,20 data export included dose volume histograms (dvhs) for all target and oar volumes ; however, the dvhs were recalculated using the focal treatment planning system to ensure consistency in volume calculation methods.21 the quality assurance team reviewed each plan and recorded the actual calculated dose for the target volumes and oar for each of the specified dose constraint and planning objective levels. centres were instructed to follow their departmental procedures with regard to imrt planning technique ; however, a recommendation to use seven to nine beams was made.12 for centres unfamiliar with imrt planning for acc, an imrt planning guide was included as an appendix to the protocol.12 data were analysed using the stata (version 12.1 ; statacorp lp, college station, tx) program. doses to target volumes and oar, were recorded for all submitted imrt plans. statistical analysis included basic descriptive statistics and the t - test or wilcoxon signed rank test (where data were not normally distributed) to establish what dose objectives were actually achieved for each oar. the mann whitney test was used to compare groups based on gender and n stage in the achievability of dose objectives and logistic regression was used to determine factors of significance in the ability to achieve the dose objectives. n stage was investigated as a whole, in addition to being divided into two groups : (1) n0n2 and (2) n3 only. n3 disease was considered as a separate group as this stage included bilateral inguinal or internal iliac involvement that results in higher doses delivered to the pelvis and surrounding oar. the data utilised in this investigation were collected from part of the assessment of new radiation oncology treatments and technologies (anrotat) project. this project was undertaken by the trans tasman radiation oncology group (trog) in response to a commission by the australian government department of health and ageing to develop and pilot an evaluation framework of new technologies with a view to providing improved funding for imrt if evidence compiled by the project was compelling.13 the purpose, objectives and specific details of the project are described in the anrotat protocol.12,13 data collection occurred between june 2011 and april 2012. the acc section of the anrotat project consisted of five component studies including credentialing, dosimetry and prospective toxicity and quality of life assessment. the data collected in the imrt dosimetry component of the project have been utilised in this investigation. eligibility criteria included histological confirmation of squamous cell carcinoma, intention to electively irradiate all pelvic nodal groups up to l5-s1 interspace (including mesorectal, presacral, internal iliac, external iliac, ischiorectal fossa, obturator and inguinal groups) and planned for radical chemoradiotherapy. patient ct data sets were excluded if there was evidence of metastatic disease, if they had prior pelvic radiotherapy or surgery (e.g. vaginal hysterectomy) or had a hip prosthesis. the selection comprised a mix of different stages for both male and female patients, all positioned supine, who met the eligibility criteria (table1). stage t1n0 was excluded, as some centres do not routinely electively irradiate the inguinal nodes in this setting. ethics approval was obtained for use of the retrospective data sets for all participating centres. each of the participating centres were allocated three of the 15 data sets, and prepared an imrt plan for each data set. as the purpose of this investigation was to evaluate dose distribution and not to assess variations in contouring, all target volumes and oar structure sets were included with each ct data set. target volume contours were marked and reviewed by two radiation oncologists and were delineated using the guidelines proposed by the australasian gastrointestinal trials group (agitg).14 target volumes provided were planning target volume (ptv) 45 gy (elective volume), ptv54 gy - p (primary volumes with n3 (n represents node with the 1, 2, 3 representing the number of involved nodes). a 1 cm clinical target volume (ctv) to ptv margin was employed for all data sets. if the ptv contour extended outside the skin, it was cropped to the skin surface. for planning purposes, objective ptv volumes cropped 5 mm from the skin surface were created by the centre for plan optimisation. oar contours provided included bm, bowel, left and right femoral head and necks, external genitalia and bladder.12 the bowel was delineated as a cavity, 15 mm superior to the cranial aspect of the ptv, extending inferiorly to the recto - sigmoid junction based on the study by devisetty and colleagues.12,16 external genitalia included the perineum with the cranial extent at the upper level of the pubic symphysis. all imrt plans were generated using a simultaneous integrated boost technique according to the anrotat protocol.12 the prescription consisted of two dose levels (1) ptv-45 gy receiving 45 gy and (2) ptv-54 gy receiving 54 gy delivered over 30 fractions. dose coverage requirements and dose planning objectives for oar for the anrotat protocol are shown in table2. the primary objective was to achieve target volume coverage followed by the oar dose constraints and planning objectives listed in order from most to least important. these constraints were adapted from the radiation therapy oncology group (rtog) 05 - 29 phase 2 study protocol that assessed imrt in anal cancer with one exception.17 the small bowel constraint was modified to bowel based on data published by devisetty and colleagues.16 this paper provided dose volume correlation with acute bowel toxicity in acc patients undergoing chemoradiation, and hence supported the anrotat project 's health economic analyses. at the commencement of the anrotat project, there was no other relevant literature providing oar dose correlation with acute toxicity in acc radiotherapy. imrt dose planning objectives / constraints dose planning objectives are listed in descending order of priority. dx, dose covering x% of the volume ; vx, volume of organ receiving xgy. centres were directed that effort should be made to achieve the listed dose constraints but were advised that constraints can not always be achieved, and therefore planning objectives were specified listed in order from highest to lowest priority. failure to meet some dose constraints would result in minor or major deviations (table3). these deviations were set by the group to assist in assessing clinical safety and compliance. the only oar that major deviation levels were specified for were the bowel and femoral heads as these were the only two oar with published dose volume toxicity data in acc patients for acute bowel toxicity and femoral neck fractures.16,18 the threshold levels for these structures were based on these studies. plan review definitions of major and minor deviations ptvs, planning target volumes ; dx, dose covering x% of the volume ; vx, volume of organ receiving xgy. all plans were submitted electronically in dicom rt or rtog format for review using the focal treatment planning system (elekta ab, stockholm, sweden).19,20 data export included dose volume histograms (dvhs) for all target and oar volumes ; however, the dvhs were recalculated using the focal treatment planning system to ensure consistency in volume calculation methods.21 the quality assurance team reviewed each plan and recorded the actual calculated dose for the target volumes and oar for each of the specified dose constraint and planning objective levels. centres were instructed to follow their departmental procedures with regard to imrt planning technique ; however, a recommendation to use seven to nine beams was made.12 for centres unfamiliar with imrt planning for acc, an imrt planning guide was included as an appendix to the protocol.12 data were analysed using the stata (version 12.1 ; statacorp lp, college station, tx) program. doses to target volumes and oar, were recorded for all submitted imrt plans. statistical analysis included basic descriptive statistics and the t - test or wilcoxon signed rank test (where data were not normally distributed) to establish what dose objectives were actually achieved for each oar. the mann whitney test was used to compare groups based on gender and n stage in the achievability of dose objectives and logistic regression was used to determine factors of significance in the ability to achieve the dose objectives. n stage was investigated as a whole, in addition to being divided into two groups : (1) n0n2 and (2) n3 only. n3 disease was considered as a separate group as this stage included bilateral inguinal or internal iliac involvement that results in higher doses delivered to the pelvis and surrounding oar. data sets were planned using a median of 9 (range 721 beams) co - planar, step - and - shoot imrt beams. the large number of beams required in some instances can be attributed to the requirement of a carriage shift in the transfer of the beams from the treatment planning system to the linac (meaning some beams were split into two). of the 30 plans submitted, an average total monitor units (mu) of 965 with a range of 4761683 mu was recorded for 27 plans. the average time purely spent planning (not including review or quality assurance time) was 343.7 min (range 50868 min). a total of 30 imrt plans were reviewed and target volume coverage was achieved. the mean coverage of 98% of ptv45 gy, ptv54 gy - p and ptv54 gy - n (d98) was at least 95% of the prescribed dose level with mean doses of 44.9, 51.9 and 51.5 gy respectively. a comparison of oar dose planning objectives and the achieved dose / volumes is shown in table4. the percentage of plans that failed each oar dose planning objective, in addition to the percentage of plans that classified as a major deviation for the applicable oar, is displayed in table5. median planned doses exceeded one or more of the planning objectives for the bowel, external genitalia and bladder with more than 50% of plans failing two out of three planning objectives assessed for these oar. in contrast, all median planned doses for the bm and femoral head and necks met the defined planning objectives. the median planned volume significantly exceeded the prescribed dose constraint / planning objective by 39.9 cm for bowel v45 (p < 0.001) and 1.1 cm for bowel v50 (p < 0.001), 16.3% for external genitalia v20 (p < 0.001), 16.5% for bladder v35 (p < 0.001) and 6.2% for bladder v40 (p = 0.01). comparison of oar dose planning objectives / constraints with the mean value from submitted plans. absolute volumes are indicated in units of cm, remaining values are a percentage of the defined volume oar, organs at risk ; vx, volume of organ receiving xgy. denotes statistical significance. percentage of plans that failed each oar dose planning objective oar, organs at risk ; vx, volume of organ receiving xgy. a statistically significant difference was demonstrated between the median volumes achieved for bowel v30 (p = 0.04) and bm v30 (p = 0.03) and bm v40 (p = 0.05) when considering patient gender. specifically, the median volume for these oar in female patient data sets exceeded the male data sets (table6). the bowel volume was greater in females than males with an average volume of 617.8 and 421.2 cm respectively. oar dose / volumes achieved according to grouping oar, organs at risk ; vx, volume of organ receiving xgy. denotes statistical significance. as a function of n stage, a statistically significant difference in the achievability of v50 (p = 0.05) for bm was found. n stage was further divided into 2 groups : n0n2 patients and n3 patients. based on this grouping, the median planned volumes for all dose planning objectives were higher in those with n3 disease for the bowel and external genitalia and for the bm v30 dose level (table6). this reached statistical significance for bm v50 (p = 0.03) and external genitalia v30 (p = 0.03) and v40 (p = 0.01). the mean bowel and bm volumes for the n3 group were 783.8 and 559.3 cm respectively. comparatively, the mean bowel and bm volumes for n0n2 patients were 486.4 and 466.1 cm respectively. when these factors were tested in the logistic regression model, gender was found to be the only factor of statistical significance in the likelihood of achieving the bowel v50 constraint (p = 0.03) and the bm v30 constraint (p = 0.04). logistic regression demonstrated that the model based on gender correctly classified 70% and 76.7% of data sets to achieve the v50 bowel and v30 bm planning objectives respectively. data sets were planned using a median of 9 (range 721 beams) co - planar, step - and - shoot imrt beams. the large number of beams required in some instances can be attributed to the requirement of a carriage shift in the transfer of the beams from the treatment planning system to the linac (meaning some beams were split into two). of the 30 plans submitted, an average total monitor units (mu) of 965 with a range of 4761683 mu was recorded for 27 plans. the average time purely spent planning (not including review or quality assurance time) was 343.7 min (range 50868 min). the mean coverage of 98% of ptv45 gy, ptv54 gy - p and ptv54 gy - n (d98) was at least 95% of the prescribed dose level with mean doses of 44.9, 51.9 and 51.5 gy respectively. a comparison of oar dose planning objectives and the achieved dose / volumes is shown in table4. the percentage of plans that failed each oar dose planning objective, in addition to the percentage of plans that classified as a major deviation for the applicable oar, is displayed in table5. median planned doses exceeded one or more of the planning objectives for the bowel, external genitalia and bladder with more than 50% of plans failing two out of three planning objectives assessed for these oar. in contrast, all median planned doses for the bm and femoral head and necks met the defined planning objectives. the median planned volume significantly exceeded the prescribed dose constraint / planning objective by 39.9 cm for bowel v45 (p < 0.001) and 1.1 cm for bowel v50 (p < 0.001), 16.3% for external genitalia v20 (p < 0.001), 16.5% for bladder v35 (p < 0.001) and 6.2% for bladder v40 (p = 0.01). comparison of oar dose planning objectives / constraints with the mean value from submitted plans. absolute volumes are indicated in units of cm, remaining values are a percentage of the defined volume oar, organs at risk ; vx, volume of organ receiving xgy. percentage of plans that failed each oar dose planning objective oar, organs at risk ; vx, volume of organ receiving xgy. a statistically significant difference was demonstrated between the median volumes achieved for bowel v30 (p = 0.04) and bm v30 (p = 0.03) and bm v40 (p = 0.05) when considering patient gender. specifically, the median volume for these oar in female patient data sets exceeded the male data sets (table6). the bowel volume was greater in females than males with an average volume of 617.8 and 421.2 cm respectively. oar dose / volumes achieved according to grouping oar, organs at risk ; vx, volume of organ receiving xgy. denotes statistical significance. as a function of n stage, a statistically significant difference in the achievability of v50 (p = 0.05) for bm n stage was further divided into 2 groups : n0n2 patients and n3 patients. based on this grouping, the median planned volumes for all dose planning objectives were higher in those with n3 disease for the bowel and external genitalia and for the bm v30 dose level (table6). this reached statistical significance for bm v50 (p = 0.03) and external genitalia v30 (p = 0.03) and v40 (p = 0.01). the mean bowel and bm volumes for the n3 group were 783.8 and 559.3 cm respectively. comparatively, the mean bowel and bm volumes for n0n2 patients were 486.4 and 466.1 cm respectively. when these factors were tested in the logistic regression model, gender was found to be the only factor of statistical significance in the likelihood of achieving the bowel v50 constraint (p = 0.03) and the bm v30 constraint (p = 0.04). logistic regression demonstrated that the model based on gender correctly classified 70% and 76.7% of data sets to achieve the v50 bowel and v30 bm planning objectives respectively. published data on the use of imrt in acc are limited in comparison to other treatment areas such as head and neck and prostate cancer. north american studies, such as the rtog 05 - 29 trial, have demonstrated that acc imrt provides acceptable tumour control and toxicity.17 dosimetric studies have reported that dose to surrounding oar, such as bowel, bm, external genitalia, bladder and femoral heads can all be significantly reduced with imrt, whilst still delivering the prescribed dose to the tumour.2,10,15,22 however, setting the priorities for each of these oar planning objectives in imrt is challenging in acc due to the number of oar.15 the greatest challenge in acc imrt is the limited published evidence of specific toxicity data and has led to planning objectives that are not entirely evidence based or which are adapted from other cancer sites. this study showed that planning objectives set for the femoral heads and bm were achieved for all dose levels. in contrast, median planned dose / volume was significantly exceeded for : the v45 and v50 for the bowel (p < 0.001 and 0.001), external genitalia v20 (p < 0.001) and bladder v35 and v40 (p < 0.001 and p = 0.01). this was further supported by 73% of plans failing to meet the v45 bowel objective, 80% of plans failing to meet the external genitalia v20 and 73.3% and 60% of plans failing to meet the bladder v35 and v40 objectives respectively (table5). these results are similar to those reported in a study by devisetty. comparing imrt to helical tomotherapy in acc.16 using oar dose planning objectives also based on the rtog 05 - 29 trial, they found that the bowel v30 and v50 and bladder v30, v40 and v50 constraints could not be achieved.16 in contrast to the present study, they found that all planning objectives set for the external genitalia could be achieved.16 in the present study, 80% and 50% of plans failed to achieve the v20 and v30 planning objectives respectively (table5). one reason for this difference is our study included the perineum with the external genitalia contour, with more of the perineum receiving dose when the inguinal nodes are treated.. there could be numerous reasons why certain oar dose planning objectives could not be achieved. in the anrotat project, the protocol stated that the primary objective of the plan was to achieve the required target volume coverage followed by the oar listed in order of priority. major and minor deviations were only specified for the bowel and femoral heads, with the other planning objectives provided as a guide to minimise dose to other oar. consequently, it is possible that some objectives were relaxed in order to meet those deemed a higher priority with major deviation thresholds specified. bowel and femoral heads were given high priority as bowel toxicity should be reduced to minimise treatment breaks, and late femoral fractures have been reported following acc radiotherapy. another reason could be attributable to the range of experience amongst the participating centres in the use of imrt, and specifically acc imrt with some centres indicating that they had not planned or planned very few imrt acc patients previous to this study. this was in part demonstrated by the great range of planning times that were recorded by the participating centres. joseph and colleagues commented that the quality of the plan produced could be highly user dependent and can depend on both the experience of the planner and the time and effort expended by the planner in the optimisation process.23 this study sought to ascertain patient and tumour factors that could influence the likelihood of achieving these constraints. the strongest relationship found was that between gender and the ability to meet the bowel and bm dose planning objectives. it was found that the median planned volumes exceeded the v45 and v50 bowel dose planning objectives in female patients. this finding is not surprising due to the differences in pelvic anatomy between men and women.23 in this study, women had a larger bowel volume within the pelvis and therefore, more dose delivered. bivariate analysis also demonstrated a link between n stage and the volume of irradiated bm. when dividing n stage into n0n2 versus n3 stage disease, significant relationships were found with external genitalia v30 and v40 also. the median volume exceeded the planning objective for all dose levels for bowel and external genitalia for those in the n3 group. n3 disease represents a more advanced stage of acc, which includes either bilateral inguinal or bilateral internal iliac nodes. delivering boost doses to involved lymph nodes will result in higher doses delivered to the bowel, bm and the perineum and external genitalia. firstly, in order to establish realistic oar planning objectives for use in acc imrt, consistent contouring is imperative. the purpose of the acc contouring guidelines published by the agitg was to facilitate consistency in practice.14 the establishment of oar planning objectives in acc imrt, however, can be problematic as target volumes vary between patients, disease stages, variation in bowel and external genitalia / perineum volumes can be significant based on a patient 's gender and body habitus. however, if target and oar volumes are contoured in accordance with the agitg guidelines, the following recommendations can be made based on the results of the current study : oar planning objectives for the femoral head, bm and the bowel v30 are realistic for use in daily practice. it is important to note that the femoral head and bowel v30 dose constraints were based on published clinical evidence of dose toxicity correlation.16,18 it was found that the remaining planning objectives for the bowel, external genitalia and bladder were not able to be consistently achieved with the treatment planning systems available for the study, and as such, may need to be relaxed, or potentially omitted in the case of lower priority oars (refer to table3). from our data, the irradiation of higher volumes of bowel and bm to higher doses in patients with n3 disease and in females should be expected. positioning the patient prone on a belly board for example, may reduce the volume of bowel irradiated, particularly for female patients with higher stage nodal disease or ensuring good bladder filling to displace bowel superiorly out of the irradiated field. strict bladder planning objectives may not be relevant when planning acc imrt, as dvh toxicity data correlation is not well established for the bladder.17,24 the lower planning objectives for the external genitalia, if including the perineum, (i.e., v20) may be removed. realistic planning objectives or better understanding of what is achievable in terms of oar doses, has the potential to minimise planning time (the mean planning time in this study was 5.7 h) as radiation therapists will not spend excess time attempting to achieve goals that are unable to be met. ultimately, the development of appropriate dose constraints for oar in acc imrt can only be properly generated from dose toxicity correlations, which is currently lacking, particularly in terms of acute toxicity outcomes, in acc. our study has generated hypotheses for testing in future, larger studies and data that centres are able to review and compare their own planning data with. a major limitation of the study was that it was not specifically designed for the purpose of assessing the feasibility of dose planning objectives in imrt for acc but involved analysing data collected as part of the anrotat project. consequently, inter - centre variation was not able to be adequately assessed as there was not one common data set planned by all centres. another limitation is the small sample size included in this study, although being a representative mix, means that cautious interpretation of the results should be undertaken as it may have impacted on the power of the analysis to detect significant differences. it should also be noted that there were differences in the way oar volumes were contoured between the rtog study (on which the oar dose planning objectives were based) and the current study. further prospective investigation involving larger sample sizes and correlation with toxicity data is warranted and the establishment of a patient registry would be beneficial.25 the dose planning objectives for the femoral heads, bm and bowel v30, used in the anrotat project, provide a good starting point for acc imrt planning. achievability of other dose planning objectives for the bowel and constraints for external genitalia and bladder can be more heavily influenced by factors such as sex and n stage. to facilitate the successful use of oar dose planning objectives, as centres gain more experience in imrt planning for acc and more specific toxicity data become available, these dose planning objectives should be reviewed and further refined. | introductionintensity modulated radiotherapy (imrt) is ideal for anal canal cancer (acc), delivering high doses to irregular tumour volumes whilst minimising dose to surrounding normal tissues. establishing achievable dose objectives is a challenge. the purpose of this paper was to utilise data collected in the assessment of new radiation oncology treatments and technologies (anrotat) project to evaluate the feasibility of acc imrt dose planning objectives employed in the australian situation.methodsten australian centres were randomly allocated three data sets from 15 non - identifiable computed tomography data sets representing a range of disease stages and gender. each data set was planned by two different centres, producing 30 plans. all tumour and organ at risk (oar) contours, prescription and dose constraint details were provided. dose volume histograms (dvhs) for each plan were analysed to evaluate the feasibility of dose planning objectives provided.resultsall dose planning objectives for the bone marrow (bm) and femoral heads were achieved. median planned doses exceeded one or more objectives for bowel, external genitalia and bladder. this reached statistical significance for bowel v30 (p = 0.04), v45 (p < 0.001), v50 (p < 0.001), external genitalia v20 (p < 0.001) and bladder v35 (p < 0.001), v40 (p = 0.01). gender was found to be the only significant factor in the likelihood of achieving the bowel v50 (p = 0.03) and bm v30 constraints (p = 0.04).conclusionthe dose planning objectives used in the anrotat project provide a good starting point for acc imrt planning. to facilitate clinical implementation, it is important to prioritise oar objectives and recognise factors that affect the achievability of these objectives. |
arf was first discovered, purified, and functionally defined as the protein cofactor required for cholera toxin catalyzed adp ribosylation of the stimulatory regulatory subunit (gs) of adenylyl cyclase (enomoto and gill, 1980 ; kahn and gilman, 1984) and, shortly thereafter, was shown to be a gtp - binding protein (kahn and gilman, 1986). use of the acronym arf is currently preferred to adp ribosylation factor, as only arf16 shares the cofactor activity for cholera toxin and because adp ribosylation does not appear to be involved in any aspect of the normal cellular actions of any member of the family. the use of all capital letters (e.g., arf1) refers specifically to the human gene or protein, whereas when only the first letter is capitalized (e.g., arf1), it may refer to the protein from more than one species, an activity, or a group of proteins. since their discovery, they have been found to be ubiquitous regulators of membrane traffic and phospholipid metabolism in eukaryotic cells (for reviews and discussion of arf actions see nie. arfs are soluble proteins that translocate onto membranes in concert with their activation, or gtp binding. the biological actions of arfs are thought to occur on membranes and to result from their specific interactions with a large number of effectors that include coat complexes (copi, ap-1, and ap-3), adaptor proteins (gga1 - 3 and mint1 - 3/x11-/apba1 - 3), lipid - modifying enzymes (pld1, phosphatidylinositol (4,5)-kinase, and phosphatidylinositol (4)-kinase), and others. arf proteins are activated by guanosine diphosphate (gdp) to gtp exchange, which is stimulated by the sec7 domain of arf guanine nucleotide exchange factors, and their activity is terminated upon the hydrolysis of gtp, which is stimulated by interaction with an arf gtpase - activating protein. cloning and sequencing of the first arf family member (sewell and kahn, 1988) led directly to the realization that arfs are closely related to both the ras and heterotrimeric g protein subunit families of gtpases, and all are thought to have arisen from a common ancestor. the very high degree of conservation of arf sequences in eukaryotes (74% between human and yeast) was also noted early on and has allowed the ready identification of orthologues in every examined eukaryote, including giardia lamblia, which lack ras and g protein subunits (murtagh., 1992). cloning by low stringency hybridization and chance led to the identification of additional members of the arf family in a wide array of eukaryotic species., 1991) and were named in their order of discovery (price., 1988 ; bobak., 1989 ; kahn., 1991 ; lee., the first confusion in the nomenclature was that the current human arf4 was originally published with the name arf2 (kahn,., 1991). in fact, humans appear to have lost the arf2 orthologue, which is present in other mammals (including rats, mice, and cows). the combination of protein sequence comparisons and intron / exon boundaries of arf genes led to further classification of the six mammalian arfs into classes : class i (arf13 are > 96% identical), class ii (arf4 and arf5 are 90% identical to each other and 80% identical to the other arfs), and class iii (arf6 is 6469% identical to the other arfs). phylogenetic analyses support the conclusion that the three classes of arf diverged early, as flies and worms have single representatives of each of the three classes, and the number of genes / proteins in class i and ii were later expanded in vertebrates. the initial criteria for naming new arfs were functional, and only those proteins that could (1) serve as cofactors for cholera toxin, (2) rescue the lethal arf1arf2 deletion in saccharomyces cerevisiae, and (3) directly activate pld were given the name arf. thus, with the chance cloning of an essential gene in drosophila melanogaster that encoded a protein closely related to the arfs (5060% identity) but lacking in these activities, it was named arflike (tamkun., 1991). when orthologues were found in several other species, the name was changed to arf - like 1 (arl1) in those species (kahn., 1992 ; breiner. note that although the name arf still denotes a protein with one or more specific functions or activities, the term arl does not. 1994) revealed the existence of a large number of mammalian cdnas encoding closely related proteins. the next to be cloned and sequenced were arl2 (clark., 1993), arl3 (cavenagh., 1994), arl4 (schurmann., each of the encoded proteins has a glycine at position 2, the site of n - myristoylation in all arf proteins. note that although arl2 and arl3 have the nh2-terminal glycine, they appear not to be substrates for n - myristoyltransferases. around this time, a protein with similar percent identities to the arf and arls was found, but it lacked the nh2-terminal glycine, was membrane associated, and displayed distinctive nucleotide handling properties (schurmann. thus, it was given the name arf - related protein 1 (arfrp1) to distinguish it from the arls and arfs. we realize today that this was unfortunate, as several of the more recently identified arls also have functions and biochemical properties that are quite divergent from arfs. sar1 was among the earliest members of the arf family sequenced, and it came out of genetic screens in the yeast s. cerevisiae as a suppressor of sec12(ts) (nakano and muramatsu, 1989). its name is derived from its identification as a secretion - associated and ras - related protein. cloning of the mammalian orthologues revealed the presence of two closely related (90% identity) proteins / genes (kuge., 1994). with 96% identical), class ii (arf4 and arf5 are 90% identical to each other and 80% identical to the other arfs), and class iii (arf6 is 6469% identical to the other arfs). phylogenetic analyses support the conclusion that the three classes of arf diverged early, as flies and worms have single representatives of each of the three classes, and the number of genes / proteins in class i and ii were later expanded in vertebrates. the initial criteria for naming new arfs were functional, and only those proteins that could (1) serve as cofactors for cholera toxin, (2) rescue the lethal arf1arf2 deletion in saccharomyces cerevisiae, and (3) directly activate pld were given the name arf. thus, with the chance cloning of an essential gene in drosophila melanogaster that encoded a protein closely related to the arfs (5060% identity) but lacking in these activities, it was named arflike (tamkun., 1991). when orthologues were found in several other species, the name was changed to arf - like 1 (arl1) in those species (kahn., 1992 ; breiner., 1996 ; lowe., 1996). note that although the name arf still denotes a protein with one or more specific functions or activities, the term arl does not. pcr amplification with degenerate oligonucleotide primers (clark., 1993 ; schurmann., 1994) revealed the existence of a large number of mammalian cdnas encoding closely related proteins. the next to be cloned and sequenced were arl2 (clark., 1993), arl3 (cavenagh., 1994), arl4 (schurmann., 1994), and arl5 (breiner., 1996). each of the encoded proteins has a glycine at position 2, the site of n - myristoylation in all arf proteins. note that although arl2 and arl3 have the nh2-terminal glycine, they appear not to be substrates for n - myristoyltransferases. around this time, a protein with similar percent identities to the arf and arls was found, but it lacked the nh2-terminal glycine, was membrane associated, and displayed distinctive nucleotide handling properties (schurmann., 1995). thus, it was given the name arf - related protein 1 (arfrp1) to distinguish it from the arls and arfs. we realize today that this was unfortunate, as several of the more recently identified arls also have functions and biochemical properties that are quite divergent from arfs. sar1 was among the earliest members of the arf family sequenced, and it came out of genetic screens in the yeast s. cerevisiae as a suppressor of sec12(ts) (nakano and muramatsu, 1989). its name is derived from its identification as a secretion - associated and ras - related protein. cloning of the mammalian orthologues revealed the presence of two closely related (90% identity) proteins / genes (kuge., 1994). with < 30% identity to arfs or arls, the sar proteins are only slightly closer in sequence to arfs than to other families of gtpases, but they also share considerable functional relatedness to arfs in that they act through the recruitment of coat proteins or complexes to initiate vesicle budding. an interesting variation is found in ard1/tripartite motif 23 (trim23), a 64-kd protein that possesses a 20-kd domain at its cooh terminus with 60% identity to arfs (mishima., 1993). originally named based on the presence of the arf domain, ard1 is also a member of the trim family, from which it obtained its current name, trim23. a large extension is also seen in arl13b, a protein of 428 residues that contains an arl domain at its nh2 terminus (chiang., 2004 ; fan., 2004 although the nh2-terminal portion of trim23 may possess gtpase - activating protein activity toward its own arf domain (vitale., 1996) and e3 ubiquitin ligase activity (vichi., 2005), the cooh - terminal portion of arl13b has no defined domains or functions to date. as the discussion above suggests, there are no shared functions or activities that justify grouping arf, arl, and sar proteins into a family with a common nomenclature. similarities in protein sequences within the arf family were first identified by alignment and phylogenetic analyses and were shown to provide distinct signatures that allowed differentiation from ras, g protein subunits, and other gtpases. these include an nh2-terminal extension, a glycine acceptor for myristate at position 2, an aspartate at position 26 (in contrast to the glycine 12 of ras that carries oncogenic potential), and other residues that are very highly conserved within the family. these early observations were put on more solid functional footing when they were found to map to unique elements in their three - dimensional structures, which allow for the gdp / gtp switch to be coupled with interaction signals opposite to the nucleotide - binding site (for review see pasqualato., 2002). the prominent feature of this unique nucleotide switch is a nonconventional gdp - bound form in which the two strands that connect the nucleotide - sensitive switch 1 and 2 regions (also called the interswitch) are retracted in the protein core and must undergo a two - residue shift to reach the active conformation (fig. however, the interswitch can not do so unless the nh2-terminal helical extension, which caps the interswitch and locks it in the retracted conformation, has been displaced. in the case of arf1, biochemical studies have established that this requires the interaction of the nh2 terminus with membranes, thus allowing the nucleotide - binding site to detect and respond to remote protein membrane interactions (antonny.,, each sar has an nh2-terminal amphipathic helix that functions as a structural gdp / gtp switch to anchor the gtp - bound form to membranes of the endoplasmic reticulum (huang. furthermore, membrane insertion of this nh2-terminal helix was recently shown to initiate membrane bending at the early stages of copii coat assembly and to be subsequently required for the completion of copii vesicle fission (lee., 2005). in arfs, arls, and sar proteins, the interswitch toggles from an unusual retracted conformation in the gdp - bound form that is fastened by the nh2-terminal helix to an exposed conformation in the gtp - bound form that is stabilized by the w / gg / r signature (shown here for arf6-gdp and arf6-gtp). this large conformational change, which involves a two - residue -strand register shift in the core of the g domain, allows the nucleotide - binding site to detect remote interactions taking place at the nh2 terminus (reproduced from pasqualato., 2001 with permission). structural analysis of arf1 and arf6 gdp / gtp cycles and their comparison with those of small gtp - binding proteins whose interswitch does not toggle identified three structural determinants for this movement : a helical nh2-terminal extension that fastens the retracted, gdp - bound interswitch ; a shorter interswitch that can retract completely ; and a sequence signature (wdvggqxxxrxxw) that provides both flexibility for the movement (gg) and hydrogen bonds for stabilization of the active conformation (r / w). these characteristics are present in all arf and most arl sequences, which, therefore, are predicted to have the ability to undergo the interswitch toggle to detect interactions opposite to the nucleotide - binding site, whatever their nature, and propagate them to this site (pasqualato., 2002). these structural criteria for unifying arf and arl proteins as a family have since been supported by various structures of gdp - bound arf and arl proteins (table s1, available at http://www.jcb.org/cgi/content/full/jcb.200512057/dc1). it should be noted, however, that one subgroup, arl4, has a long interswitch that may have lost the ability to toggle, whereas structures of nh2-terminally truncated arl8a and arl8b bound to gdp have a gtp - like conformation. this suggests that truncation of the nh2 terminus is sufficient in this family to destabilize the retracted interswitch or that these proteins have lost their ability to undergo the interswitch toggle. recent work on arl3 suggests that proteins interacting with the nh2 terminus could also work as the displacing factor as an alternative to membranes (behnia. table i contains information on proposed and previous names as well as other information on the human arf family members. est and genomic sequencing resulted in the identification of subsequent arf - like proteins, and these proteins / genes were often misnamed or named multiple times by different research groups. some of these names suggest relationships that are misleading, and some are called arfs despite (presumably) lacking any arf activities. in many cases, one protein has been referred to by four different names, and some proteins / genes were named by curators of databases responding to specific requests in a manner that disagreed with common usage by researchers in the field. the confusion is magnified when species differences are considered (e.g., yeast arl3 is the orthologue of arfrp1). the arf family gtpases : summary of names, identifiers, and nh2-terminal sequences because of previous usage and to avoid confusion, the new assignments result in there being no gene / protein named arl7 or arl12. see table s2 for a list of earlier names and references in which earlier names were used (available at http://www.jcb.org/cgi/content/full/jcb.200512057/dc1). the sequence currently in the database is predicted to be incorrect, and our corrected information was used herein. the need for a generally agreed upon nomenclature for the arf family has become acute as a result of increasing confusion and interest in their study. it is not possible today to propose a completely consistent nomenclature, as there are simply too many studies with some of the earlier discovered proteins (e.g., arfrp1 should be an arl). the nomenclature developed and described in this article builds on previous efforts to describe phylogenetic relationships and bring consistency to nomenclature (pasqualato., 2002 ; li., 2004 it is the result of many discussions between researchers in the field and with the hugo genome nomenclature committee (hgnc) and has been widely circulated to arf family researchers. we describe the presence in the human proteome of 29 members of the arf family and a system for naming newly identified proteins in human or other species. the use of letter suffixes is reserved for those groups of proteins within the family that share higher percent identities and are, therefore, likely to share some level of functional redundancy. one exception to this is the arl13a and arl13b proteins, which have been given a common number based upon phylogenetic evidence. the consensus nomenclature for the arf family is shown in table i along with previous names and unique gene / protein identifying information. note that in three cases (arl5c, arl9, and arl16), the intron / exon boundary predictions in the database are thought to be incorrect (based upon comparisons with sequences in other species), resulting in differences in the predicted protein sequences. in these cases, we use our corrected sequences for comparisons and provide the predicted protein sequences of the human proteins (see supplemental material, available at http://www.jcb.org/cgi/content/full/jcb.200512057/dc1). in addition, there is one case (arl9) in which it appears that alternative splicing yields two different proteins, one of which is truncated and predicted to be unable to bind nucleotides, so both are provided in the supplemental protein sequence material. we also identify several gene sequences that have questionable est / mrna support and are likely pseudogenes derived from members of the arf family. these genes, which are annotated by the hgnc, are therefore not included as arf family members and are listed, along with their identifiers, in table ii. it is expected that additional pseudogenes will be found and added to this list over time. we also note some uncertainty as to whether arl5c in table i is a transcribed gene, as it may lack part of the consensus gtp - binding signature depending on which predicted protein sequence is used. pseudogenes of the arf family in the human genome this is a list of the hgnc - recognized pseudogenes from the arf family along with their locations in the genome, accession numbers, and gene identifiers. finally, we note that although the large majority of arf family members appear to have very broad and perhaps ubiquitous tissue expression patterns, a few are far more restricted in their expression. thus, it is expected that further additions and perhaps even deletions will be needed to keep the nomenclature of this family current and as consistent as possible. to ensure that new family members are assigned unique symbols, we strongly encourage authors to consult the hgnc before publishing any new names for members of this gene / protein family. this is a confidential service provided by the hgnc that will help prevent future confusion from arising. we also suggest that curators and researchers focusing on other organisms use the information provided in this article as much as possible to simplify and clarify the nomenclature across species. other researchers supporting the use of this nomenclature include : bruno antonny, bill balch, vytas bankaitis, gary bokoch, juan bonifacino, chris burd, jim casanova, tamara caspary, dany cassel, rick cerione, pierre chardin, philippe chavrier, shamshad cockcroft, peter cullen, ivan de curtis, maria antonella de matteis, julie donaldson, cryslin d'souza - schorey, john exton, victor faundez, jim goldenring, jean gruenberg, alan hall, fuchu he, wangjin hong, victor hsu, mary hunzicker - dunn, trevor jackson, cathy jackson, hans joost, toshi katada, fang - jen lee, michel leroux, jennifer lippincott - schwartz, john logsdon, alberto luini, vivek malhotra, ed manser, tobias meyer, paul melancon, joel moss, aki nakano, kazu nakayama, tommy nilsson, susanne pfeffer, richard premont, paul randazzo, anne ridley, scotty robinson, anne rosenwald, craig roy, hisataka sabe, randy schekman, nava segev, val sheffield, phil stahl, elizabeth sztul, chris turner, anne theibert, martha vaughan, kanamarlapudi venkateswarlu, fred wittinghofer, keqiang ye, and marino zerial. | the ras superfamily is comprised of at least four large families of regulatory guanosine triphosphate binding proteins, including the arfs. the arf family includes three different groups of proteins : the arfs, arf - like (arls), and sars. several arf family members have been very highly conserved throughout eukaryotic evolution and have orthologues in evolutionally diverse species. the different means by which arf family members have been identified have resulted in an inconsistent and confusing array of names. this confusion is further compounded by differences in nomenclature between different species. we propose a more consistent nomenclature for the human members of the arf family that may also serve as a guide for nomenclature in other species. |
the neurogenic niche in the adult zebrafish pallium, accessible for live imaging, contains radial glia - like anscs (fig. 1b) with their cell bodies lining the ventricular wall. radial processes of anscs span the brain parenchyma to contact the basement membrane. the morphology and the antigen profile of anscs in the zebrafish pallium are reminiscent of radial glial (rg) cells in the developing mouse telencephalon. the anscs in the zebrafish pallium do not only share the morphological and immunohistochemical characteristics with the mammalian rg cells in the developing brain, but also have the capacity to generate new neurons. however, in contrast to the new neurons produced in the developing mammalian cerebral cortex, the new neurons produced by the pallial anscs in the intact brain of zebrafish do not migrate away from the stem cell zone and are instead deposited directly below the progenitor zone (fig. 1b) that do not have stem cell characteristics (intermediate progenitors (ips) or non - glial progenitors). traumatic brain injury induces a specific program in the anscs and intermediate progenitors resulting in the production of new neurons necessary for regeneration. in contrast to the intact brain, these newborn neurons migrate larger distances to repopulate the damaged brain areas (fig. importantly, the small stab wound injury induces the restorative neurogenesis without an impact on the ongoing neurogenesis present in the intact brain. this indeed raises the question of the origin of the new neurons engaged in the repair process. moreover, it remains unclear to which extent the cellular processes underlying restorative neurogenesis recapitulate those sustaining the normal generation of adult - born neurons. to address these questions, we repetitively imaged anscs in the tg(gfap::gfp)mir2001 transgenic fish line that expresses gfp in all anscs. to reliably re - identify anscs in different imaging sessions, we sparsely labeled a small number of them by electroporation of a reporter (tdtomatomem) encoding plasmid. as the ubiquitous cytomagalovirus (cmv) promoter drives the expression of the reporter, we could follow not only anscs, but also their progeny that lost the radial morphology and glial marker expression. our results confirmed previous observations that in the intact brain anscs are mostly quiescent and only a small proportion of anscs divide or change their identity to generate progeny (anscs activation) at any discrete time point. both live in addition, we could observe the generation of gfap::gfp - positive glial cells indistinguishable from the mother cell indicative of self - renewal. indeed, all ansc divisions in the intact brain generated at least one cell with radial morphology and also expressing gfap::gfp. whether some of these glial cells are already a differentiated cell type (possibly homologous to the ependymal cells in the mammalian brain) or a quiescent stem cell is not clear yet. however, virtually all gfap - positive glial cells in the zebrafish pallium can be recruited into the cell cycle upon notch inhibition, strongly suggesting that at least some of the newly generated gfap::gfp - positive cells with radial morphology are quiescent anscs. the generation of oligodendrocytes from anscs in the zebrafish pallium has not been directly assessed. however, ansc - derived cells mostly express either gfap or neuronal lineage markers (sox2 and hucd) (unpublished data), accentuating the idea that only neurons and anscs / ependyma are generated from nscs in this brain region. this is indeed very similar to the adult mouse dg, where anscs do not generate oligodendrocytes. oligodendrocytes are generated in this region exclusively by neural / glial antigen2 (ng2)-positive progenitors in the adult mouse sez oligodendrocytes are also generated, but the neuronal and oligodendroglial lineages are separated in two independent populations of progenitors. although the predominantly neuronal output appears to be a hallmark of anscs in the vertebrate brain, the cohort size produced by a single ansc differs greatly between species and analyzed areas (fig. 2). despite the difference in clone size, the output of a single ansc seems to be defined by the number of divisions of intermediate progenitors. in the zebrafish pallium, these progenitors divide once or twice before terminally differentiating into neurons interestingly, this low degree of lineage amplification in the zebrafish pallium is reminiscent of the behavior of progenitors in the adult mouse dg, supporting the suggested homology between the two regions (fig. 2). also in the developing rodent dorsal telencephalon, basal / intermediate progenitors divide few times before generating neurons (fig. however, this situation contrasts with the mouse ventral telencephalon, in which multiple rounds of division of progenitors greatly amplify the neuronal output (fig. 2a) similarly, in the sez niche a high degree of amplification occurs at the transit amplifying progenitor (34 divisions) and neuroblast (12 divisions) level moreover, anscs also divide asymmetrically several times each 23 weeks to produce a larger neuronal output containing several cohorts (fig. unlike in the pallium, the neurogenic niche in the zebrafish subpallium appears more similar to the mouse sez (fig. 1c), as there are proportionally more ips and some of these also migrate to the olfactory bulb. interestingly, in the zebrafish subpallium the anscs exhibit low levels or no expression of glial markers and, because they express nestin and the tight junction component zona occludens 1 (zo-1), they resemble neuroepithelial cells (fig. the mixture of radial and tangential migration of the nsc progeny in this region makes a clonal analysis challenging. thus, the behavior of subpallial ansc in the zebrafish at the single cell level remains to be assessed. (a) different modes of neuron generation in the developing brain. in the zebrafish hindbrain and xenopus optic tectum, some nscs directly convert into neurons (direct conversion), depleting themselves. at early embryonic stages in the zebrafish and mouse telencephalon, nscs proliferate (14 rounds in the mouse) to increase their number (symmetric proliferative divisions). as development advances, nscs divide asymmetrically to give rise to another nsc and a neuron directly (direct neurogenesis, red box) or to a nsc and an intermediate progenitor, that amplifies the neuron production (indirect neurogenesis). in the mouse cortex the degree of amplification via intermediate progenitors differs in the cortex and the ventral telencephalon of the mouse (asterisk), since cortical ips divide once or twice before generating neurons, whereas in the lateral ganglionic eminence they divide several times. at the end of neurogenesis, most nscs undergo a terminal division (symmetric neurogenic divisions). adult nscs have a limited self - renewal capacity, and generate neurons via transit amplifying progenitors (taps) and neuroblasts. despite the high degree of amplification, many neurons die and only a few manage to survive and integrate in the olfactory bulb circuits. anscs undergo a few rounds of asymmetric divisions to generate neurons via intermediate progenitors, after which they terminally differentiate into astrocytes. compared to the sez, there is a lower amplification at the intermediate progenitor level. neurogenesis occurs either through direct conversion, depleting the nsc, or asymmetric division, maintaining the ansc. besides the self - renewing asymmetric division, after injury, anscs divide not only asymmetrically, as in the intact brain, but also symmetrically to generate two intermediate progenitors, increasing the neuronal output. abbreviations : ansc - adult neural stem cell ; dg - dentate gyrus ; ip - intermediate progenitor ; rg - radial glia ; sez - sub - ependymal zone ; tap - transit amplifying progenitor. (a) different modes of neuron generation in the developing brain. in the zebrafish hindbrain and xenopus optic tectum, some nscs directly convert into neurons (direct conversion), depleting themselves. at early embryonic stages in the zebrafish and mouse telencephalon, nscs proliferate (14 rounds in the mouse) to increase their number (symmetric proliferative divisions). as development advances, nscs divide asymmetrically to give rise to another nsc and a neuron directly (direct neurogenesis, red box) or to a nsc and an intermediate progenitor, that amplifies the neuron production (indirect neurogenesis). in the mouse cortex the degree of amplification via intermediate progenitors differs in the cortex and the ventral telencephalon of the mouse (asterisk), since cortical ips divide once or twice before generating neurons, whereas in the lateral ganglionic eminence they divide several times. at the end of neurogenesis, most nscs undergo a terminal division (symmetric neurogenic divisions). adult nscs have a limited self - renewal capacity, and generate neurons via transit amplifying progenitors (taps) and neuroblasts. despite the high degree of amplification, many neurons die and only a few manage to survive and integrate in the olfactory bulb circuits. anscs undergo a few rounds of asymmetric divisions to generate neurons via intermediate progenitors, after which they terminally differentiate into astrocytes. compared to the sez, there is a lower amplification at the intermediate progenitor level. neurogenesis occurs either through direct conversion, depleting the nsc, or asymmetric division, maintaining the ansc. besides the self - renewing asymmetric division, nscs also undergo symmetric amplifying divisions (symmetric ansc division). (e) modes of neurogenesis and division in the injured adult zebrafish pallium. after injury, anscs divide not only asymmetrically, as in the intact brain, but also symmetrically to generate two intermediate progenitors, increasing the neuronal output. abbreviations : ansc - adult neural stem cell ; dg - dentate gyrus ; ip - intermediate progenitor ; rg - radial glia ; sez - sub - ependymal zone ; tap - transit amplifying progenitor. the broad spectrum of the single ansc behaviors leading to the production of differently sized neuronal cohorts prompted us to search also for the mechanisms enlarging the neuronal output during regeneration, that allow the replacement of the lost neurons without an obvious impact on the ongoing neurogenesis. several cellular mechanisms such as increased ansc proliferation, proliferation of the non - glial progenitors, decreased cell death etc. indeed, both anscs and non - glial progenitors increase their proliferation after brain injury however, we could not observe multiple divisions of a single ansc using live imaging in vivo, but rather increased recruitment of quiescent anscs. interestingly, we observed that some of the anscs dividing after injury did not self - renew, but rather exhausted themselves by a symmetric division generating two non - glial progenitors. this mode of division, not present in the intact brain, might constitute an advantage after injury, since it generates a larger neuronal output from a single ansc compared to an asymmetric division. curiously, enhanced ansc depletion has also been observed in the dg of a mouse model of neuronal hyperactivity, suggesting some conservation of ansc reaction to challenge in different vertebrate species. this nsc exhaustion phenomenon would predict a decreased capacity of the zebrafish brain to regenerate damages induced by the repetition of the insult. alternatively, anscs in the zebrafish might be heterogeneous and could contain more primitive, undifferentiated cells with the capacity to repopulate anscs depleted after injury and enable proper regeneration even after multiple injuries. indeed, in the zebrafish caudal fin amputation paradigm, progenitor cells completely reconstitute the entire damaged tissue without losing efficiency even after repeated amputations. therefore, it would be important to address if anscs have the capacity to repopulate the neurogenic zone and allow tissue restoration even after multiple insults or if the different organs have different regeneration capacity depending on the characteristics of the somatic stem cells residing within the given organ. an important novel feature of adult neurogenesis in the zebrafish telencephalon uncovered by our in vivo imaging was the direct conversion of a considerable proportion of anscs (50 % of all anscs generating neurons) into a neuron without any cell division. in fact, single progenitors labeled at the neural rod stage directly convert into neurons without cell division in the developing zebrafish hindbrain. also in xenopus laevis, time - lapse imaging demonstrated that the majority of rg cells in the developing optic tectum directly differentiate into neurons. as direct conversion had never been observed in the adult brain, this could either mean that anscs in the zebrafish telencephalon possess this unique capacity, or that direct conversion has not yet been detected in the adult brain of other species due to the lack of suitable technical approaches such as live imaging. at present, we can not elucidate if the population of anscs that directly convert to neurons is a specific population or if these cells also have the capacity to divide. in fact, both in the zebrafish and in the mouse embryo, dividing rg cells generate neurons directly without going through an intermediate progenitor state (fig. 2a, direct neurogenesis). in our study however, we followed anscs for at least 2 weeks before they directly converted into neurons, suggesting that these cells either have an extremely long cell cycle or do not need to divide at all to generate neurons. notably, after injury anscs divide more and change their division mode to produce large cohorts of neuronal progeny needed in these hostile conditions. in contrast, direct conversion would allow slow, but constant addition of new neurons to the slowly growing adult. it is still to be addressed if the anscs undergoing direct conversion in the intact brain would become activated after injury and divide in a symmetric neurogenic manner (a mode of anscs division that we observe only in the injured brain) to produce a larger neuronal output and deplete themselves after injury. alternatively, direct conversion might be actively blocked but these anscs would be kept at the vz for the slow neuronal production after the brain is regenerated. in the adult zebrafish pallium, new neurons are added either by asymmetric division of anscs, thus maintaining the stem cell pool, or by direct conversion depleting the stem cell pool. our live imaging showed that the proportion of anscs that directly convert to neurons and deplete themselves (17%) is considerably higher than the proportion of anscs dividing symmetrically to amplify the stem cell population (1%) in the intact brain. indeed the number of proliferating anscs was decreasing in 6 and 10 months old animals compared to 3 months old animals, which correlates with the previously described decrease in neurogenesis in the aged zebrafish pallium. these data therefore would support the hypothesis that ansc depletion is the cellular basis for the age - dependent decline of neurogenesis in zebrafish. however, edelmann observed that the total number of gfap::gfp -positive glia (regardless of their proliferative status) does not decrease with aging. the cellular mechanisms that maintain the ependymoglia in the adult brain remain to be investigated, but one possible explanation would be that the modes of stem cell division / behavior could be changed toward the gliogenic / ependymoglial fate in aging animals. in our study we used 23 months - old animals and followed single cells for one month but it is possible that in older animals there is a prevalence of symmetric anscs divisions that would replenish the pool of ependymoglia. more in vivo imaging of single anscs at these later stages would be needed to clarify these issues. importantly, in the mouse neurogenic niches, sez and dentate gyrus, there is a limited number of self - renewing divisions of anscs followed by terminal differentiation into the neuronal or astrocytic lineage. therefore the exhaustion of anscs in vertebrates is a common trait, possibly including the glial fate as the final differentiation step. in summary, the in vivo imaging we established allowed for the first time the visualization of anscs in their natural niche in a vertebrate model, not only in physiological conditions but also after brain damage. consequently, several features of the behavior of individual anscs were revealed at the single cell level, at an extent that could not be assessed by previous population - based studies. the knowledge acquired with the observation of nsc behavior in the zebrafish brain may serve as a basis to conduct studies on modulating nsc activity in the diseased brain. for the application of these findings in mammalian disease models it will be important to compare the nsc behavior in zebrafish and mammals. we want to thank magdalena gtz, david petrik, filippo calzolari, sven falk and rosario sanchez - gonzalez for critical reading of the manuscript. we also gratefully acknowledge funding to jn from the german research foundation (dfg) by the sfb 870 and spp integrative analysis of olfaction and to jsb from the fundao para a cincia e tecnologia, portugal (fct). | abstractadult neural stem cells (anscs) generate new neurons that integrate into the pre - existing networks in specific locations of the vertebrate brain. moreover, anscs contribute with new neurons to brain regeneration in some non - mammalian vertebrates. the similarities and the differences in the cellular and molecular processes governing neurogenesis in the intact and regenerating brain are still to be assessed. toward this end, we recently established a protocol for non - invasive imaging of ansc behavior in their niche in vivo in the adult intact and regenerating zebrafish telencephalon. we observed different modes of ansc division in the intact brain and a novel mode of neurogenesis by direct conversion, which contributes to stem cell depletion with age. after injury, the generation of neurons is increased both by the activation of additional anscs and a shift in the division mode of anscs, thereby contributing to the successful neuronal regeneration. the cellular behavior we observed opens new questions regarding long - term ansc maintenance in homeostasis and in regeneration. in this commentary we discuss our data and new questions arising in the context of ansc behavior, not only in zebrafish but also in other species, including mammals. |
emphysematous pancreatitis (ep) is a rare life - threatening condition of the pancreas, associated with gas - forming bacteria wherein there is gas formation within or around the pancreas, identified by abdominal computed tomography (ct) scan. although no definite predisposing factors have been identified, it is seen to be commonly occurring in patients with diabetes mellitus, which predisposes to gas gangrene and tuberculosis (tb) with hiv infection. until date, only few discrete cases have been reported. olanzapine is an atypical antipsychotic drug used either alone or in combinations for various psychiatric conditions, e.g., schizophrenia, bipolar disorder or depressive episodes associated with it, treatment of acute resistant depression in adults etc., besides prominent central nervous system side - effects, some important gastrointestinal / endocrine adverse effects are increased appetite and weight gain, hyperglycaemia, hypertriglyceridemia (htg) etc., none of which is directly related to ep. few cases of olanzapine induced oedematous, mild pancreatitis are reported in literature. in our case, the patient developed severe necrotising ep without any of the proposed predisposing factors except intake of olanzapine. to the best of our knowledge, a 32-year - old male patient, weighing 86 kg (body mass index 30 kg / m) diagnosed as a case of bipolar disorder 5 months ago was started on lithium 400 mg daily initially. even with an incremental dose of lithium over 2 months, he had not improved. therefore, olanzapine (oleanz, sun pharmaceutical industries ltd., mumbai, india) 5 mg twice daily was added to his regimen. after 2 months of starting olanzapine, he developed nausea, vomiting, and severe epigastric pain without any history of haematemesis, melaena and jaundice., he had a heart rate of 105 - 115/min with blood pressure 110/56 mm hg and respiratory rate of 24 - 28/min and was febrile. abdominal examination demonstrated epigastric tenderness with guarding including normal liver dullness on percussion and absent bowel sound. his pain was increasing in intensity and referred to back. on the 10 day of pain abdomen, he developed breathlessness and admitted to intensive care unit in view of low arterial o2 saturation and dyspnoea. blood investigation showed serum lipase 900 u / l (normal level 10 - 140 u / l), serum triglyceride 560 mg / dl (normal level 1000 mg / dl predispose to pancreatitis, the moderate htg probably increased susceptibility in our patient. incidence of drug induced acute pancreatitis is about 0.1 - 2% of all cases and it is usually reversible when the causative drug is stopped. drug induced pancreatitis has some common features like temporal association and, known response pattern. peripancreatic local application of metronidazole is a new approach to increase drug delivery to target site with minimum systemic adverse effects. though pancreatic penetration of metronidazole after intravenous injection has been found to be highest (99%) in the necrotic tissue, it can also induce pancreatitis in 2% cases. additive effect of two drugs causing higher risk of pancreatitis had been reported with olanzapine and lisinopril. the patient improved and survived from severe pancreatitis after stoppage of offending drug and conservative management including minimally invasive intervention. we have described a rare case of ep in young male due to development of diabetes, htg and immunosuppression predisposed by olanzapine. this drug should be used cautiously in individuals with increased risk of developing pancreatitis. in patients with this drug prescription for long duration, a high index for clinical suspicion of pancreatitis should be kept in mind with monitoring for hyperglycaemia and htg. local application of metronidazole may be effective in intr - abdominal or retroperitoneal anaerobic infection. | a 32-year - old male presented to our intensive care unit with severe abdominal pain and was diagnosed as acute pancreatitis after 2 months of olanzapine therapy for bipolar disorder. his serum lipase was 900 u / l, serum triglyceride 560 mg / dl, and blood sugar, fasting and postprandial were 230 and 478 mg / dl, respectively on admission. contrast enhanced computed tomography (cect) of abdomen was suggestive of acute pancreatitis. repeat cect showed gas inside pancreas and collection in peripancreatic area and patient underwent percutaneous drainage and antibiotics irrigation through the drain into pancreas. we describe the rare case of emphysematous pancreatitis due to development of diabetes, hypertriglyceridemia and immunosuppression predisposed by short duration olanzapine therapy. |
haemochromatosis is the abnormal accumulation of iron in parenchymal organs, leading to organ toxicity. secondary or acquired haemochromatosis can be caused by diseases such as thalassemia or myelodisplastic syndrome, especially if patients have received a large number of blood transfusions, rarely in hepatitis c, alcoholism, chronic liver disease, some types of anaemia, and other illnesses. patient b.c. was diagnosed with thalassemia intermedia at the age of 3 years, by performing haemoglobin electrophoresis which showed a decreased a1 haemoglobin level, and an increase of a2 and foetal haemoglobin level of 45%. at the age of 8 years he was given a replacement and chelation iron therapy with intermittent desferal at the paediatric clinic up to the age of 18, when he was guided towards the clinic of haematology. 1), skin hyper - pigmentation, ogival palate, dental implant defects, simian hand (fig. 2), weakness of scapular girdle muscles, irregular heart sounds, tachycardia (a.v. 100 beats / min), unorganized extrasystoles, enlargement of abdomen with postoperative scar, caused by giant hepatomegaly occupying the entire abdomen, increased onsistency(fig. longilin asthenic constitution type, weakness of scapular girdle muscles simian hand appearance, with hyperpigmentation of the palmar creases abdomen enlargement caused by giant hepatomegaly occupying the entire abdomen. postoperative scar (splenectomy) paraclinical testing : esr 86mm/1h, hb 5.2g / dl, l 18 200/mm3, t 168 000/mm3, mtc 1%, ns 2%, s 43%, ly 21%, eo 2%, mn 6% erythroblasts 25% marked poikilocytosis, erythrocytes that have the appearance of a shooting target, jolly bodies. peripheral blood smear (fig.4,5)-microcytes, hypochromia, great erythrocyte disorder, marked poikilocytosis with erythrocytes that have the appearance of a shooting target, presence of erythroblasts on smear (a sign of the presence of extramedullary haematopoiesis outbreaks) gpt 145 ui / l, got 121 ui / l, fa 345 ui / l, serum protein electrophoresis pt 6.8g / dl, albumins 59%, alpha 1 4%, alpha 2 5.4%, beta 12%, gamma globulins19.6%, bt 3.2mg / dl, bi 2.1mg / dl, creatinine 0.67mg / dl, blood glucose 376mg / dl, serum iron 279mg / dl, serum ferritin 6 800mg / ml, blood glucose 338mg / dl-245mg / dl-112mg / dl treated with rapid - acting insulin, requiring higher doses to regulate blood glucose values. marked poikiloctosis, with presence of erythrocytes that have the appearance of a shooting target, erythroblasts in peripheral blood (a sign of the presence of extramedullary haematopoiesis outbreaks), and appearance of great erythrocyte disorder rx heart lung pa (fig.6) - slightly enlarged heart, there can be seen disseminated haemosiderin deposits on both lung areas. an increased interstitial drawing with the presence of nodules with a diameter of 2 - 3 mm, due to haemosiderin deposits echocardiogram - left ventricular ejection fraction (lvef) 72%, without obvious heart disease. in some patients, noticeably those with thalassemia major, sickle cell disease, myelodysplastic syndrome, aplastic anaemia, hemolytic anaemia, and refractory sideroblastic anaemia, who may become transfusion - dependent and receive excess iron with each transfusion (that the body has no means to excrete), iron gradually accumulates in various tissues, causing morbidity and mortality. the ferritin does not circulate in blood but is deposited in tissues and is unavailable when cells need iron. major organs affected by this surplus iron include the heart, lung, liver, and endocrine glands. when the plasma iron - binding protein transferrin is oversaturated, as in transfusion - induced iron overload, the excess iron circulates as relatively free non - transferrin - bound iron (ntbi). this ntbi is rapidly taken up by liver and other tissues. transferrin - bound iron (tbi) is also taken up by these cells through the hepcidin mechanism, which is increased in such states. the most common cause of morbidity is cardiomyopathy (30%) that is induced by iron overload. cardiac involvement in haemochromatosis typically results in congestive cardiomyopathy ; a restrictive cardiomyopathy due to haemochromatosis is distinctly rare. the average time for the development of heart failure in transfused, unchelated patients is 10 years. there were not revealed any echocardiogram changes, lvef value was preserved without rhythm or management disturbances. early cirrhotic changes can be observed as early as age 7 years in some people with thalassemia. iron accumulation primarily occurs in hepatocytes can predispose to liver fibrosis and cirrhosis, and potentially hepato - cellular carcinoma. the presented patient developed cirrhosis with haemochromatosis after 22 years of evolution of the disease, vascularly modified after another six years of evolution, with the presence of oesophageal varices at endoscopic examination, the hepatic portal vein echography 16 mm. patient death occurred in upper gastrointestinal bleeding due to the rupture of oesophageal varices, followed by irreversible hemorrhagic shock and cardiopulmonary arrest. if nmr is available, cardiac iron levels and cardiac function should also be measured by nmr yearly and every 6 months in patients who have intensive chelation therapy. t2<20ms indicates a high iron load and is associated with low ejection fraction. by performing nmr there can be identified patients with high risk of deterioration of cardiac function before the onset of clinical picture and the intensifying of chelation therapy. pulmonary hypertension is another complication that occurs with a relatively high frequency in patients with thalassemia intermedia, and several factors were involved in its pathogenesis : chronic anemia and hypoxia, iron overload, splenectomy, hypercoagulability, microthrombotic disease. more than one third of transfusion - dependent patients with -thalassemia major exhibit a restrictive lung function defect, which may improve with chelation therapy. although heart - lung radiography revealed the presence of haemosiderin deposits, ventilatory function was not impaired, ventilatory tests being within normal limits. there was also reported an association between elevated liver iron concentration and the occurrence of endocrinopathy, bone disease and vascular morbidity. our patient developed secondary diabetes at the age of 28 years, requiring therapy with high doses of insulin in order to correct blood glucose values. failure of puberty was the major clinical endocrine problem, and it was present in 51% of boys and 47% of girls, all older than 15 years. it is advisable to measure ferritin levels at least every 3 months and iron studies every year. liver iron levels should be measured annually (either by biopsy or noninvasively) and every 3 - 6 months in patients who undergo intensive chelation for heart failure. the case presented in this paper is that of a patient with thalassemia intermedia, integumentary secondary haemochromatosis, cirrhosis with haemochromatosis, and secondary diabetes, who died at the age of 33 years because of upper gastrointestinal bleeding due to the rupture of oesophageal varices. | haemochromatosis is due to excessive accumulation of iron in tissues and organs impairing their function. the most common haematologic disorders that are subject to an intensive transfusion regimen bringing excess iron in the body are : thalassemia and myelodysplastic syndrome. the value of serum ferritin in these patients (indicator of iron stores condition) reaches high values. red cell substitution bringing additional iron intake must be accompanied by administration of chelation therapy in order to prevent haemochromatosis and related complications. we present the case of a patient with thalassemia intermedia, integumentary secondary haemochromatosis, cirrhosis with haemochromatosis, and secondary diabetes, who died at the age of 33 years because of upper gastrointestinal bleeding due to the rupture of oesophageal varices. |
18f - fluoro-2-deoxy - d - glucose - positron emission tomography (fdg - pet) scan is increasingly being used not only in oncology but also in some nononcological specialties, such as neurology, cardiology, and infectious diseases. the fundamental principle of fdg - pet scan is that the nuclide, 18f - fdg has two parts, namely, the vector part (i.e., 2-deoxy - d - glucose) and the positron emitting nuclide part (i.e., 18f), and when it gets preferentially taken up by rapidly dividing cells (i.e., malignant cells), it gets trapped within the cells and emits positron radiation which is then detected by the scintigraphy. this is called metabolic trapping and this forms the basis for fdg - pet scanning. in oncology, fdg - pet has many important clinical applications including initial cancer staging as well as monitoring tumor response to anticancer therapy in lung, colon, lymphoma, melanoma, esophageal cancer, and head and neck and breast cancer. in neurology and cardiology, fdg - pet is a useful tool for localization of epileptogenic zones inside the brain and is a gold standard since the first observation of fdg uptake in metastatic thyroid cancer over 20 years ago, there have been growing interests in evaluating the role of fdg - pet scanning in the management of thyroid neoplasms. also with an increased number of fdg - pet scans now being performed, an increasing number of incidental thyroid lesions (or the so - called thyroid incidentalomas) have been found and this itself poses a diagnostic challenge to clinicians. given that fdg - pet imaging could provide potentially relevant information on tumor biology and the scan results may enable to prognostically stratify thyroid carcinoma patients, the author believes that it would be both timely and important to examine the prognostic significance of fdg - pet positivity in thyroid carcinoma and the role of fdg - pet in diagnosis and management of thyroid carcinoma by a review of the current literature. it has been well recognized that thyroid carcinoma metastases which are shown up on fdg - pet scan do not take up radioactive iodine (rai). numerous reports have confirmed this important relationship. at the same time, it was noted that those metastases which did not take up rai were generally less differentiated on histology and behaved clinically more aggressively. therefore, fdg - pet positivity in thyroid carcinoma could imply clinically more aggressive tumors and poorer overall prognosis. however, before discussing the implications of fdg positivity in thyroid carcinoma, it should be realized that there are fundamental differences in the management of fdg - pet positivity between primary and persistent / recurrent thyroid carcinoma. as a result unlike persistent / recurrent carcinoma, the number of studies examining the relationship between fdg - pet positivity and tumor behavior or prognosis for primary thyroid carcinoma remained relatively few. as the role of fdg - pet in preoperative thyroid carcinoma staging remains undefined, the majority of these primary thyroid carcinomas exhibiting fdg - pet positivity are incidentally found cancers or incidentalomas (see figure 1). reasons for the lack of enthusiasm for fdg - pet as a staging tool include that fdg - pet scan remains a relatively expensive preoperative imaging modality when compared to ultrasound (usg) which is the recommended imaging modality before surgery, and relative to the other imaging modalities, fdg - pet does not seem to provide any additional staging information (such as the status of the cervical lymph nodes) to an extent of altering the surgical management. as a result, fdg - pet scan has not been routinely advocated as a preoperative staging tool, although there might be a role in selected, more aggressive pathologies, such as hurthle cell or anaplastic thyroid carcinoma [1012 ]. nevertheless, one of the first studies examining the relationship between tumor behavior and fdg - pet positivity in primary thyroid carcinoma was reported by jeong.. in this study, they reported 44 consecutive patients with papillary thyroid microcarcinoma (ptmc) confirmed by usg and fine needle aspiration cytology (fnac) who subsequently underwent fdg - pet scans before surgery. the clinicopathological characteristics of these 44 ptmc were correlated with the activity of the fdg - pet scan or fdg standardized uptakes values (suvs). although there was a strong correlation between suvs and extrathyroidal extension of ptmc in the univariate analysis, the study did not find any association between the degree of suv and extrathyroidal extension or other aggressive tumor features in the multivariate analysis. only age > 45 and tumor site turned out to be the two significant factors for determining extrathyroidal extension in primary ptmc. suvs were correlated with tumor size, but this was not unexpected because there is the partial volume effect between small- and large - sized lesions. therefore, based on this initial study, fdg - pet positivity was not associated with more aggressive tumor behavior or worse tumor characteristics. however, a more recent study found that for ptmcs which were fdg nonavid, they were not only significantly smaller sized tumors but also less frequent perithyroidal tumor invasion and lymphovascular invasion when compared to the ptmcs which were fdg avid. this implies that fdg - pet positivity might be associated with a more aggressive tumor behavior in primary thyroid carcinoma. however, since tumor size is an important factor for fdg - pet positivity as it relates to the partial volume effect, it would be more appropriate to adjust for tumor size in these clinicopathological studies. yun. reported their retrospective study involving 87 patients with a unifocal ptmc who underwent preoperative fdg - pet before total thyroidectomy and central neck dissection. they defined positive fdg uptake in ptmcs as a discernible focal fdg uptake whereas negative fdg as no discernible fdg uptake. all scans were assessed by two experienced nuclear medicine specialists blinded for patients ' clinical and pathological variables. in their multivariate analyses, among other factors such as gender, age, and tumor size, fdg - pet positivity was the only significant factor which strongly correlated with extrathyroidal extension (or = 5.95 ; 95% ci : 2.1316.6) and central lymph node metastases in primary ptmc. this result indicates that visual fdg - pet positivity in ptmcs is a potential risk factor which could be useful in preoperative risk stratification. one of the potential clinical applications would be to use the preoperative finding of fdg - pet positivity to select patients for more extensive thyroid resection (i.e., hemithyroidectomy versus total thyroidectomy in ptmc) or for prophylactic central neck dissection at the time of total thyroidectomy as it is currently only indicated for high - risk tumors. our previous studies examining the behavior of fdg - avid primary thyroid carcinoma (mostly incidental thyroid carcinoma) also suggested that these tumors are not only larger in size, more likely to be clinically significant (42.9% versus 2.9%, p = 0.001) but also more aggressive in terms of having higher frequency of tumor bilaterality (45% versus 0%, p = 0.040) when compared to non - fdg - avid tumors [16, 17 ]. therefore, our data would support the fact that fdg - pet positivity implies more aggressive tumor biology and poorer prognosis in primary thyroid carcinoma. numerous studies have found that metastases from thyroid carcinoma which do not concentrate rai but take up fdg are clinically more aggressive and have poorer tumor differentiation. esteva. studied 50 differentiated thyroid carcinoma (dtc) patients with elevated thyroglobulin (tg) and negative whole - body scan (wbs) after total thyroidectomy and rai ablation. the authors correlated the postoperative fdg - pet finding and clinicopathological variables of the primary tumor and found that fdg - pet was positive in 32/39 patients with confirmed persistent or recurrent thyroid carcinoma. when compared to the fdg - pet - negative group, the fdg - pet - positive group had significantly larger primary tumor size (2.82 cm versus 1,72 cm, p 2.0 as the criterion for fdg - pet positivity [28, 32 ]. however, for whatever cut - off in suv, there is always going to be a trade - off between false positives and false negatives. evaluated the association between suv uptake over time and malignancy in follicular neoplasm by performing serial fdg - pet scans over a 2-hour period and measuring the area under the suv curve (auc). they demonstrated no significant difference in auc, but found a difference in the dynamics of suv change over time between benign and malignant lesions. due to the significant overlap in auc, they concluded that fdg - pet was not able to predict malignancy in a follicular neoplasm. however, since most of these reported series were retrospective in design and the patient selection was not formally standardized, there is a need for a large, well - designed prospective study. recently, traugott. reported the results of 51 patients with indeterminate fnac as an interim analysis of their prospective trial which began in 2004. their data suggested that fdg - pet was an accurate diagnostic modality for identifying malignancy in thyroid nodules at least 1 cm in diameter and with indeterminate fnac, with 100% sensitivity and npv. they concluded that fdg - pet was of value in excluding malignancy in thyroid nodules with indeterminate fnac. to overcome the spatial resolution limitation of the fdg - pet, their study only included solitary or dominant nodule that measured 1 cm on usg. to achieve adequate power, they aimed to recruit 125 patients and results would be available within the next few years. a recent systematic review and meta - analysis evaluated the role of fdg - pet in patients with indeterminate thyroid fnac. in this meta - analysis, they analyzed over 200 patients and found that the pooled sensitivity, specificity, ppv, and npv were 95%, 39%, 96%, and 60%, respectively. the authors concluded that a negative fdg - pet scan in patients who had thyroid nodules > 15 mm with indeterminate fnab results excluded thyroid cancer. conversely, a positive fdg - pet result did not identify cancer because approximately 50% of these patients had benign nodules. they concluded that the incorporation of fdg - pet into the initial workup of such patients before surgery deserves further investigation. however, there are some concerns using fdg - pet in this group of patients. firstly, follicular thyroid carcinoma (ftc), which accounts for 1020% of malignancy in the indeterminate group, is known to be associated with a lower suv than other histological types of thyroid carcinoma. it is also known that hurthle cell adenoma, a benign lesion, tends to have very high suvs. both entities could possibly lessen the usefulness of fdg - pet in discriminating benign from malignant lesions in this indeterminate group. furthermore, a confirmatory diagnosis in this group of fnac is often difficult to make by experienced pathologists. it is known that considerable interobserver and intraobserver variability in the histopathological diagnosis of thyroid follicular lesions has been reported [40, 41 ]. in one recent study, among 15 cases of suspected follicular variant of ptc (fvptc), only 2 cases (13.3%) had unanimous agreement among 6 expert pathologists. given these concerns, the role of fdg - pet in thyroid nodules with indeterminate fnac remains uncertain, but the interim results in one of the possibly largest prospective trials on fdg - pet in cytologically indeterminate nodules looked promising. hopefully, this prospective trial which is due to complete in the next few years will provide us with more information. routine rai diagnostic scanning or wbs for thyroid carcinoma surveillance is becoming less frequently used because of its relatively low sensitivity and has been supplanted by serum tg level and neck usg. nowadays, one of the commonest clinical scenarios would be for a patient with negative or normal usg but raised unstimulated tg (i.e., > 10 ng / ml or 10 ug fdg - pet is recommended in patients with suspected recurrence or metastases in the setting of raised tg levels and scan - negative metastases (see figures 2(a) and 2(b)). earlier studies found that fdg - pet was a useful diagnostic tool in the followup of postsurgical patients with dtc, negative wbs, and abnormal tg levels. fdg - pet was able to detect metastatic disease over 90% of cases and more importantly, it was able to change the surgical tactic in a 2030% of cases. reported their experience of 37 dtc patients with negative wbs and elevated tg, found that fdg - pet was able to locate occult disease in 71%, and reported a positive predictive value (ppv) of 92%. more importantly, fdg - pet was able to change the clinical management in over 50% of patients. in the presence of low tg levels, fdg - pet had the npv of 93%. esteva. reported the fdg - pet findings in 50 patients with elevated tg and negative wbs and found that fdg - pet was positive in 32/39 (82.1%) patients with confirmed recurrence and negative in 7/11 (63.6%) with no confirmed recurrence. tumor size and capsular tumor invasion were factors significantly associated with a positive fdg - pet study. they also concluded that fdg - pet was an extremely useful imaging tool in patients with negative wbs and raised tg. however, the added value of fdg - pet / ct over good - quality conventional imaging modalities such as usg, ct, mri, and diagnostic wbs in locating recurrent or persistent dtc has recently been questioned mainly of the extra cost with fdg - pet / ct and the associated radiation. lal. recently evaluated the added value of fdg - pet / ct over conventional imaging studies in 20 dtc patients with elevated tg and negative diagnostic wbs. they found fdg - pet / ct provided additional information in only 2/20 (10.0%) patients, both of whom required no additional intervention, but underestimated the extent of disease in 3/30 (15.0%) patients and led to unnecessary interventions (including surgery, rai, and antibiotics) in 3/30 (15.0%) additional patients. they concluded that fdg - pet / ct has a good sensitivity in detecting recurrent or persistent dtc, but the added value over good - quality conventional imaging is very limited. some studies evaluated the relationship between tsh level and fdg uptake intensity [4547 ]. to date, the evidence seems to suggest that a higher suvmax could be obtained in tsh - stimulated condition by recombinant human tsh (or rhtsh) stimulation, and as a result of high level of tsh, greater number of fdg - avid metastases could be detected on scanning [4547 ]. some authors evaluated the diagnostic accuracy of integrated fdg - pet / ct as it was believed that fusion of the two modalities may further enhance the sensitivity, specificity, and tumor localization (see figure 3). for other types of head and neck tumors, combined fdg - pet / ct has been shown to have improved diagnostic accuracy than fdg - pet or ct alone. razfar. evaluated the diagnostic accuracy of integrity of fdg - pet / ct in detecting recurrent / persistent dtc. they reported the sensitivity, specificity, ppv, and npv to be 80.7%, 88.9%, 94.7%, and 65.3%, respectively. from their analysis, they demonstrated there was an alteration in the treatment strategy in 28.2% as a result of adding the fdg - pet / ct information, and 21% required additional surgery. therefore, it would seem that fdg - pet / ct scan might be superior to fdg - pet as the imaging of choice in patients with a negative whole - body radioiodine scan and an abnormally raised thyroglobulin level after total thyroidectomy and radioiodine ablation. in patients with either primary or persistent / recurrent thyroid carcinoma, the finding of fdg - pet positivity or fdg - avidity usually implies poorer tumor differentiation, more aggressive tumor biology, and worse prognostic outcomes. these observations are supported by the unique mutational profile of fdg - avid tumors or metastases, namely, increased frequency of braf mutations leading to decreased nis and increased glut1. fdg - pet positivity may be a useful potential risk factor for preoperative risk stratification in primary thyroid carcinoma and this information may help in the planning of subsequent treatment strategy such as the extent of thyroidectomy, prophylactic central neck dissection, and rai ablation. fdg - pet or fdg - pet / ct scan has become the imaging of choice in patients with a negative wbs, but with an abnormally raised tg level after total thyroidectomy and rai ablation. | 18f - fluorodeoxyglucose positron emission tomography (fdg - pet) plays an increasingly important role in the prognostication, diagnosis, and management of thyroid carcinoma. for patients diagnosed with primary or persistent / recurrent thyroid carcinoma, a finding of fdg - pet positivity implies a more aggressive tumor biology and a distinct mutational profile, both of which carry prognostic significance. therefore, fdg - pet positivity may be a useful potential risk factor for preoperative risk stratification in primary thyroid carcinoma. this information may help in the planning of subsequent treatment strategy such as the extent of thyroidectomy, prophylactic central neck dissection, and radioiodine ablation. fdg - pet scan has also been found to be a useful adjunct in characterizing indeterminate thyroid nodules on fine needle aspiration cytology. however, larger - sized prospective studies are required to validate this finding. fdg - pet or fdg - pet / ct scan has become the imaging of choice in patients with a negative whole - body radioiodine scan, but with an abnormally raised thyroglobulin level after total thyroidectomy and radioiodine ablation. |
african american and hispanic american (aa / ha) women have high breast cancer mortality rates, 34.4% and 16.3%, respectively, and are underrepresented in clinical trials designed to identify effective cancer control strategies [27 ]. this underrepresentation limits the degree to which research findings can be generalized to underrepresented groups with confidence and thereby likely contributes to widening the health disparities gap for aa / ha women. while some minority women are reluctant to join research studies, others lack the information necessary to explore these options. some are never offered the information, while others lack the scientific framework needed to make an informed decision. clinical trial educational programs designed specifically for aa / ha women could help address these problems. the national cancer institute (nci) created the clinical trials education series, but according to the then director of the program, the programs were found to be disappointing when used with members of communities that are traditionally underrepresented in research studies (personal communication with margo michaels). this research team hypothesized that nci s program could be adapted to give it greater appeal to aa / ha women and refined so it would address minority women s specific concerns. seeking to avoid the cost and inefficiencies of creating and delivering multiple culturally specific programs for each of the nation s dozens of minority groups that are also underrepresented in research studies, the researchers hypothesized that weaving a sisterhood theme throughout the program would enable a single program to be effective for women from diverse communities. further, if the program was created as a slide show rather than a video, it would then be relatively inexpensive to translate a single program into multiple languages and swap out photos, as had originally been intended for the nci s clinical trials education series. qualitative methods of inquiry enhance understanding of the insider perspective of the participants and facilitate research focusing on cultural issues and diverse ethnic populations because these methods involve the in - depth exploration of a phenomenon, which is grounded in the world view, vocabulary, and experiences of those being studied. thus, the use of focus group methodology was anticipated to allow the research team to gain insight into participants beliefs and attitudes about clinical trials and a medium for their voices to be heard. this study used focus groups to guide the adaption of nci s cancer clinical trials : the basics and conversemos un rato : informacin para combatir el cncer en su comunidad powerpoint educational programs into a form that would be culturally aligned with the beliefs and attitudes of aa / ha toward clinical trials. the basics program is a 28-slide presentation covering topics such as : what are clinical trials, phases of clinical trials, randomization, types of trials, protocols, and barriers to participation. the conversemos un rato program contains 58 slides, is only available in spanish, and covers topics more in - depth than the basics program, such as : what are clinical trials, who takes part in clinical trials, types of trials, protecting patients safety, risks and benefits of trials, where to find trials, and issues of concern to latino audiences. both programs are available for public use on the nci s website (http://www.cancer.gov/clinicaltrials/resources/clinical-trials-education-series). presentation, in addition to two slides with testimonials and photographs from the conversemos un rato program and additional non - copyrighted photographs and artwork from free internet sources were used to create a program by the research team that would have universal appeal to aa / ha women. the modified program shown to focus group participants consisted of 36 slides and required approximately 30 min to view. to start this process, the authors gave the new presentation a sisterhood title and title slide and included additional pictures of women from different ethnic groups who were of diverse ages and careers throughout the presentation. other adaptations perceived to be appropriate were to more clearly define terms and more clearly connect concepts to the benefits minority women might derive from participating in research studies. two testimonials about women s experiences in learning about and enrolling into clinical trials were also incorporated into the presentation based on the nci s positive responses to these elements of its programs. one group was composed of african american women, one of hispanic american women who preferred to communicate using english, one of hispanic american women who preferred to communicate using spanish, and one that included both african american and hispanic american english - speaking women together. focus groups took place at convenient community - based locations, such as a neighborhood community center, church, community clinic, and participants homes. all focus group participants were consented in english or spanish according to the ucsd irb - approved protocol and given a copy of the human subject s bill of rights. being mindful of lack of trust in research as a major barrier to participating in clinical trials [5, 11 ], to facilitate an open, trusting environment in which participants would be comfortable to voice their opinions, approximately 2030 min was devoted to introductions, during which light refreshments and snacks were served. additionally, each focus group moderator was culturally aligned with the focus group participants, meaning they reported themselves to be of the same ethnic group. participants were told that the presenter would pause between slides to allow the participants to write down their impressions and suggestions for improving the slide. specifically, they were told that while they could ask questions between the slides, the presenter preferred that they record their questions to see if the questions were adequately addressed in subsequent slides. the rationale behind these instructions was that the educational program was created to be a self - administered program, with the opportunity to meet with a nurse or health educator afterwards to answer any questions not adequately addressed in the presentation. including the time allowed for recording notes between the slides, the 36-slide presentation required approximately 30 min. thus, from consent to completion, about 2 h were required. at the end of the focus group after each focus group, the researchers reviewed their field notes from the focus group, highlighted comments that were offered, and then clustered the comments into themes [9, 13 ]. themes for each of the four groups were collated, and subsequent changes were made to the powerpoint presentation in response to the focus group feedback. from the first series of focus groups, five main themes emerged on how to enhance the program for aa / ha women. they underscored the importance of creating aesthetically appealing slides that would help retain the viewers attention. these factors impact the effectiveness of educational programs, but can be easily overlooked in program design. for the second theme, the participants told the researchers that the purpose of the presentation needed to be made clearer. they wanted, for example, a clearer rationale for why minority women should be concerned about clinical trials and why scientists were concerned with recruiting minority women to clinical trials. they wanted more attention given to the varieties of clinical trials, including information about clinical trials for women without cancer. they also wanted less information per slide and less detailed attention to nuances, feeling that this could be offered after the women were more engaged in the informed consenting process. for the third theme, participants reported that the overall concept of the sisterhood theme was not adequately emphasized and that there should be a reference to it on every slide to tie in the theme throughout the entire program. they suggested adding testimonials from women who had gone through clinical trials to help the women relate to the overall clinical trials participation message. they wanted to be able to see women s faces and hear their voices and preferred photos over drawings of women. the participants also recommended that the pictures should show women of diverse cultures working together, instead of pictures depicting individual women from diverse cultures. further, they suggested that the voice - over should use the first - person terms of our, we, and us, instead of third - person phrasing of the information. participants suggested that using such personal pronouns could elevate camaraderie and motivation for women to battle cancer together through clinical trials. the fourth theme was the need for a better definition of the term clinical trials and to place it earlier in the presentation, because many women would not be familiar with this concept. participants emphasized the importance of using simplified vocabulary and pictures and drawings to explain complex ideas, such as informed consent or randomization. for the fifth theme, participants felt there was a need to more effectively explain the benefits and barriers of participating in clinical trials. they agreed that the fear about clinical trials was a significant impediment to clinical trials participation and needed to be addressed, along with topics such as insurance coverage for clinical trials, privacy issues, and safety assurances during the clinical trial process. participants felt that these issues were among the greatest obstacles that women would face in the initial decision making related to clinical trial participation and that these issues needed to be more effectively addressed in the presentation. once all suggested changes were incorporated, the presentation was submitted for review by a second set of focus groups, whose members mirrored the make - up of the first set of focus groups, including four focus groups of ten women each. unlike the first set of focus groups, in which participants were read the presentation, the second set of focus groups was shown a simple powerpoint presentation without any sound and asked to read through it. participants in this second set of focus groups recommended that the presentation include a voice - over superimposed onto the powerpoint slides to minimize audience fatigue from reading the presentation in its entirety. additional comments centered on small formatting changes, and there were virtually no new thematic suggestions for substantive changes to the content. instead, participants in the second set of focus groups noted that some pictures did not line up evenly and that some of the slides still had too much text. because the changes recommended by the second set of focus groups were so minimal, after these editing and voice - over changes were incorporated into the powerpoint presentation, no further focus group evaluations of the program were deemed necessary. the presentation was now ready for incorporation into the randomized controlled trial for evaluation of its efficacy. focus group methodologies are essential when there are differences in perspectives or worldviews between researchers and the communities they are targeting. this difference can stem from distinct cultural backgrounds and plays a key role in ethnic / cultural groups disparities in cancer clinical trials. focus groups give a voice to marginalized groups and thereby help to reconcile the differences among and between communities and the researchers who seek to serve them. the individuals in a focus group are viewed as the experts because they are providing their own opinions and beliefs first - hand. as can be seen in this study, focus groups generate information that helps to tailor health educational tools with appropriate cultural content and language. the feedback provided from these focus groups is anticipated to have made the clinical trials educational program a more effective tool because it will more accurately reflect the understanding, perspective, and concerns of those served. it theoretically should, therefore, have a better chance of producing a positive shift in knowledge, attitudes, and behaviors related to clinical trials than the program as it was originally conceived. because even the most carefully culturally tailored program does not guarantee a successful intervention, the next phase of this study will employ a randomized controlled trial to evaluate the impact of this educational program on participants knowledge, attitudes, and behaviors related to clinical trials. focus group participants in this study provided the research team with many strategies and critical changes for improving the cultural alignment of the breast cancer clinical trials educational program focused on aa / ha women. the breadth and depth of their assessments of the program underscore the value of securing community input to programs destined for use with specific audiences. | the dearth of evidence - based clinical trial education programs may contribute to the underrepresentation of african american and hispanic american women in cancer research studies. this study used focus group - derived data from 80 women distributed among eight spanish- and english - language focus groups. these data guided the researchers adaptation and refinement of the national cancer institute s various clinical trials education programs into a program that was specifically focused on meeting the information needs of minority women and addressing the barriers to study participation that they perceived. a sisterhood theme was adopted and woven throughout the presentation. |
rapidly developing countries such as the kingdom of saudi arabia (ksa) have experienced a dramatic decrease in physical activity mostly because of economic prosperity and industrialization, and especially in urban areas such as riyadh, ksa. data from the world health organisation (who) report on the ksa in 2005 show overall low percentages of high (16%) and moderate (16%) physical activity, and high percentages of low (68%) activity among men and women 1565 years old.1 others have also described high prevalence of physical inactivity among saudis.2,3 data from a comparative study on 20 countries showed that the ksa was among the countries that reported the highest amounts of time spent sitting.4 studies have shown that women in the ksa are more inactive than men in all age groups,1,3,5 and this is also the case for other countries in the gulf cooperation council.6 a considerable number of studies have been performed on saudi adolescents711 and young adults, including university students,12,13 and they show similar results in relation to sex. in addition, in cross - cultural studies, saudi female youth appear to be more sedentary and to have lower physical activity levels compared to female british youth.14,15 the reasons for the sedentary behaviors and low physical activity levels among saudi women compared with both saudi men and women from other countries are poorly explored. saudi arabian society, especially in urban areas, shows a combination of modernity mixed with traditional roles, values, and conservative social norms, especially for women. this is a unique socioeconomic, environmental, and cultural context that needs to be further understood there are certain sociocultural factors that appear to be barriers to women s physical activity, such as low education levels,16 wearing an abaya outside, depending on a driver, limited freedom of movement outside of the house, and employing domestic helpers. however, high socioeconomic status might, as in western countries, contribute to access to health clubs (especially in the large cities where they are available), having physical activity equipment at home, and being more liberal both the women themselves and their families. in addition, hot weather is an important barrier for exercising outdoors both for men and women. men also experience significant barriers such as low education, employing domestic helpers, and frequent use of automobiles, but they have more freedom of movement outside of the home. very few studies have addressed these issues,13,17,18 and those that have, did so from a limited perspective. to our knowledge, no study has extensively explored the sociocultural factors that contribute to low physical activity among women in the ksa. this would aid the understanding of which factors are the most important and, therefore, allow the implementation of effective health promotion strategies in the future, particularly for young saudi adults. university students are an interesting population to study and to target for change, for multiple reasons : 1) they are relatively easy to access ; 2) the university is an open milieu that is susceptible to change ; and 3) universities can support health promotion initiatives through appropriate infrastructures. university students are an important part of the young adult population, which is the largest segment of young societies such as the ksa s. based on these criteria, we selected university students with the aim of exploring different physical activity parameters, including self - efficacy, as well as perceived barriers and benefits for physical activity in saudi women. the study participants were first - year university students at princess nora bint abdul rahman university (pnu), faculty of rehabilitation and health sciences, riyadh, ksa, recruited for the study in 2014. pnu is a female - only university in the ksa that aims to educate saudi women. the study population was taken from seven bachelor s programs in health and well - being : health education and promotion, epidemiology, physiotherapy, occupational therapy, audio and speech, clinical nutrition, and radiology. the current study is cross - sectional and involved 94 female students who were 1822 years old. the questionnaire was self - administered and had five parts : 1) questions related to anthropometric and sociodemographic characteristics ; 2) the arab teens lifestyle (atls) questionnaire;19 3) the barriers self - efficacy scale (barse) ; 4) questions related to sex, social factors, and self - image ; and 5) the exercise benefits / barriers scale (ebbs). the first part involved standard questions on sex, weight, height, parents educational levels, and professions, number of housekeepers, number of family members, and illnesses among close family members. the second part was the atls questionnaire, a questionnaire that was developed for arabic youth and young adults.19 it was chosen as the most suitable scale for obtaining detailed information on the physical activity types, intensities, frequencies, and durations for this sample of young saudi females. the atls has been used in studies on physical activity in the ksa812 and in other countries in the arab world2022 among adolescents and young adults. in addition, the atls includes ten questions on dietary habits and four questions on behaviors related to physical activity (where, with whom, when, and why the physical activities were performed). the barse scale is used to assess self - efficacy, health beliefs, and motivation, which have all been shown to be related to sustained health behavior, including physical activity.23,24 the scale is built on the likelihood of a person s perceived ability to engage in physical activity three times / week in the next 3 months in the face of barriers. the barse is based on 13 questions with a ranking of 0100 (at intervals of 10) ranging from not at all confident to highly confident ; the higher the mean scale score (closer to 100), the higher the person s self - efficacy. the fourth part was developed based on literature and information from focus group discussions organized as part of the present study (conducted prior to the present study), and refers to social and cultural factors. more precisely, the fourth part considered five main social milieus (university, family, the islamic community, girlfriends, and social networks) with regard to their hindering or encouraging physical activity ; these questions have a ranking of 3 to + 3, ranging from hindering to encouraging. in addition, a number of questions related to media, self - image, and sex were added, using 5-point likert scales for each item. finally, the ebbs is a scale that has been previously used to identify perceived barriers to and facilitators of physical activity.25 the instrument is built on 43 questions divided into two dimensions, barriers and benefits. the range for the overall score is 43172 (the higher the number, the more positively physical activity is perceived) ; for the benefits, the score is 29116, and for the barriers, it is 1456 (the higher the score, the more negatively physical activity is perceived). some minor changes were needed for the atls for it to fit the needs of this specific population. the qualitative data were generated in a subgroup of students from four focus group discussions of five to eight students each. the focus group discussion sessions showed that students are very inclined to dance, and thus dancing was added to the questionnaire in the category of moderate - intensity physical activity ; these changes were approved by the original author of the atls. cronbach s alpha was used to calculate the reliability of the barse and ebbs scales. the internal consistency (alpha) for the barse scale was 0.79, and it was 0.83 for the ebbs scale, indicating good consistency for group comparisons. the study participants were first - year university students at princess nora bint abdul rahman university (pnu), faculty of rehabilitation and health sciences, riyadh, ksa, recruited for the study in 2014. pnu is a female - only university in the ksa that aims to educate saudi women. the study population was taken from seven bachelor s programs in health and well - being : health education and promotion, epidemiology, physiotherapy, occupational therapy, audio and speech, clinical nutrition, and radiology. the current study is cross - sectional and involved 94 female students who were 1822 years old. the questionnaire was self - administered and had five parts : 1) questions related to anthropometric and sociodemographic characteristics ; 2) the arab teens lifestyle (atls) questionnaire;19 3) the barriers self - efficacy scale (barse) ; 4) questions related to sex, social factors, and self - image ; and 5) the exercise benefits / barriers scale (ebbs). the first part involved standard questions on sex, weight, height, parents educational levels, and professions, number of housekeepers, number of family members, and illnesses among close family members. the second part was the atls questionnaire, a questionnaire that was developed for arabic youth and young adults.19 it was chosen as the most suitable scale for obtaining detailed information on the physical activity types, intensities, frequencies, and durations for this sample of young saudi females. the atls has been used in studies on physical activity in the ksa812 and in other countries in the arab world2022 among adolescents and young adults. in addition, the atls includes ten questions on dietary habits and four questions on behaviors related to physical activity (where, with whom, when, and why the physical activities were performed). the barse scale is used to assess self - efficacy, health beliefs, and motivation, which have all been shown to be related to sustained health behavior, including physical activity.23,24 the scale is built on the likelihood of a person s perceived ability to engage in physical activity three times / week in the next 3 months in the face of barriers. the barse is based on 13 questions with a ranking of 0100 (at intervals of 10) ranging from not at all confident to highly confident ; the higher the mean scale score (closer to 100), the higher the person s self - efficacy. the fourth part was developed based on literature and information from focus group discussions organized as part of the present study (conducted prior to the present study), and refers to social and cultural factors. more precisely, the fourth part considered five main social milieus (university, family, the islamic community, girlfriends, and social networks) with regard to their hindering or encouraging physical activity ; these questions have a ranking of 3 to + 3, ranging from hindering to encouraging. in addition, a number of questions related to media, self - image, and sex were added, using 5-point likert scales for each item. finally, the ebbs is a scale that has been previously used to identify perceived barriers to and facilitators of physical activity.25 the instrument is built on 43 questions divided into two dimensions, barriers and benefits. the range for the overall score is 43172 (the higher the number, the more positively physical activity is perceived) ; for the benefits, the score is 29116, and for the barriers, it is 1456 (the higher the score, the more negatively physical activity is perceived). a pilot test was performed with 30 students. some minor changes were needed for the atls for it to fit the needs of this specific population. the qualitative data were generated in a subgroup of students from four focus group discussions of five to eight students each. the focus group discussion sessions showed that students are very inclined to dance, and thus dancing was added to the questionnaire in the category of moderate - intensity physical activity ; these changes were approved by the original author of the atls. cronbach s alpha was used to calculate the reliability of the barse and ebbs scales. the internal consistency (alpha) for the barse scale was 0.79, and it was 0.83 for the ebbs scale, indicating good consistency for group comparisons. statistical analyses were performed using the sas software package version 9.3 (sas institute, cary, nc, usa). descriptive statistics (means and frequencies) were calculated to describe the sociodemographic characteristics as well as individual atls items, sociocultural items, and the barse and ebbs scales. for the atls questionnaire, variables were created for the total minutes for individual activities and for moderate, high, and total physical activity. the atls allows for calculating all the above, because it gives information on times / week and minutes / day for all individual activities. met calculations are based on total physical activity.26 activities are also grouped as moderate or high based on the mets for each of the activities. based on who recommendations,27 a minimum of 150 minutes / week of moderate - intensity physical activity is required for adults (equivalent to 600 met minutes / week). physical activity was used as a continuous variable and was also based on the cut - off of 600 met minutes / week of moderate physical activity. for the latter, the threshold for each individual was based solely on moderate physical activity levels (met minutes from high physical activity were not included). sedentary behavior was defined based on two questions (time spent watching tv and/or dvds / videos per day and time spent on the computer and/or the internet). the combined time for being sedentary was truncated at 16 hours / day to ensure a reasonable and realistic level of physical activity (as advised by the atls guidelines). body mass index (bmi) was calculated as follows : weight (kg / height m). for dietary habits, a cut - off of > 3 times / week was set for unhealthy food and of 0 minutes / week). based on the cut - off of 600 met minutes / week of moderate physical activity. regarding sedentary levels, an average of 6.23.5 hours / day sitting still was observed. when physical activity was studied as a continuous variable (total minutes of physical activity / week), it was not associated with bmi or with being sedentary (r=0.08, p=0.52 ; and r=0.15, p=0.23, respectively). being sedentary was positively significantly associated with bmi (r=0.35, p=0.0014), and moderate physical activity was positively significantly associated with high physical activity (r=0.34, p=0.0041). table 3 describes behaviors related to physical activity as part of the atls questionnaire, as percentages. for each question, the data show that students exercise at home (92.3%) and alone (79.5%), and that their main reasons were for health (71.8%) or for losing weight (50.0%). the students exercised mostly during the morning (41.0%) or the evening (32.0%). table 4 displays the means for the 13 individual items on the barse scale as well as for the overall scale. the highest point scores appeared for vacation (6129) and exercise alone (5931) ; being self - conscious about one s appearance had a high score as well (4631). the overall point scores showed low self - efficacy, with the average total score being < 50 (4214). all other factors had an average score of < 50, showing low self - efficacy. when the students were categorized as active or inactive (based on the 600 met minutes / week cut - off), the student s t - test showed significant differences for the overall barse scores (4613 vs 3715, p=0.02). information relating to social factors showed that among different social settings (university, family, the islamic community, girlfriends, online), the university was the only setting that hindered physical activity ; the results showed that 32% of the students selected the university, compared with 19% for family, 15% for the islamic community, 7% for girlfriends, and 13% for online networks and social media. table 5 shows the students responses as frequencies for the categories agree, neutral, and disagree on questions related to self - image, attitudes toward physical activity, and physical activity and sex. forty - four percent of the students disagreed that they would change their diets rather than engage in physical activity if they wanted to lose weight. sixty percent of the students agreed that a healthy body shape has curves, but 98% of them agreed that it is important for a woman to have a fit and healthy body. with regard to sex, 66% agreed that it is easier for men to be physically active than for women, and 60% agreed that men are more physically active than women. regarding the ebbs, the overall scale mean score was 13110 ; for the benefits and barriers subscales, the point scores were 9510 and 345, respectively, showing that physical activity is positively perceived by the students. with the individual items for benefits, the students agreed or strongly agreed on most of them, thus showing awareness of the effects of physical activity for health and well - being. the students had high percentages of disagreement for the following : 1) exercising lets me have contact with friends and persons i enjoy (41%) ; 2) exercising is a good way for me to meet new people (33%) ; and 3) exercising increases my acceptance by others (33%). regarding barriers, the students considered one important barrier to be that locations for exercise were too far away (52% agreed) and that there were too few places to exercise (75% agreed). they mostly disagreed that family members (66% disagreed) or feeling embarrassed to exercise were barriers to physical activity (71% disagreed). no association was found when students were categorized as active vs inactive for the overall scale (13211 vs 13010, p=0.44), for the benefits scale (959 vs 9510, to our knowledge, this is the first study to consider in depth a number of sociocultural factors related to physical activity among saudi females. in the current study, among first - year university students, we found that female saudi students had low levels of physical activity and high levels of sedentariness. there was an observed overall low self - efficacy that was associated with physical activity. in addition, the young women perceived physical activity as beneficial, but their physical activity levels were low. the students showed awareness of the health - related and well - being benefits of physical activity, and they considered the lack of physical activity facilities a more important barrier than their families or society. the main focus of the present study was not physical activity levels but physical activity - related sociocultural factors. however, our results are in agreement with those of previous studies with regard to the low levels of physical activity (and also with moderate physical activity levels being more common than high levels),8,10,14 the high sedentariness levels,4,8,10,14 and dietary habits (high percentages of unhealthy food consumption).8 for specific activities, our study showed a preference for walking, household activities, and moderate - intensity sports, including dance. another study also showed a preference for household activities and walking but not moderate - intensity physical activity such as dancing, very likely because dance is a modification that we added to the atls in our study.10 in a previous study, jogging and swimming were also reported as preferred activities.14 finally, in our study, moderate - intensity physical activity was positively associated with high - intensity physical activity, suggesting that students who are more active tend to be active at both moderate and high levels. students reported that they exercised mostly alone, and that factor did not appear to decrease their self - efficacy. in the same line of evidence, meeting new people or getting together with friends was not a benefit related to physical activity. in addition, the students exercised at home, and in another study, saudi adolescents also reported that they exercised alone and at home.11 if this is a genuine preference, then assumed barriers for physical activity for saudi women related to isolation and restrictions on going outside do not appear to be a major concern. however, these results should be interpreted with caution, because they might also reflect the lack of choice and/or habits rather than preferences. interestingly, our results demonstrated that the students chose physical activities for their health and for losing weight. the results from the ebbs scale also showed that the students are aware of the benefits of physical activity, for their health and their well - being. in addition, the students appear to consider physical activity to be as important as diet for losing weight and think that having a healthy body is crucial. highly scored perceived benefits of physical activity were observed in another study on saudi students (the only other study that used a benefits / barriers scale, to our knowledge).17 it must be noted that in our sample, the parents had relatively high educational backgrounds, which could be significant in encouraging overall health knowledge. young saudis from different socioeconomic backgrounds might have lower levels of awareness of physical activity.7 in addition, our students are part of health science programs and therefore might be more sensitive to and knowledgeable about health (even though they are first - year students). with regard to sociocultural barriers, information from our questions about different social factors showed encouragement toward physical activity from families, the islamic community, friends, and social media, but less from the university. among the barriers to physical activity, family discouragement was one of the least considered. another study, however, showed that norms and traditions can be significant barriers to physical activity in the ksa.18 it must be emphasized that in this study, older saudi females and those from different socioeconomic backgrounds were also studied, which implies that at least some of them were conservative. regarding the role of universities, it is important to mention that pnu is a newly established university that does not yet have available organized physical facilities. the schedule for students does not allow for any involvement in physical activity (students are picked up after study hours and do not spend additional time at pnu). based on this, the students would benefit enormously from pnu physical activity facilities if these were to be developed and offered in a systematic way. the students being self - conscious about their appearance did not show low self - efficacy, and feeling embarrassed about exercising was also not a barrier to physical activity. sixty percent of students agreed that a healthy body should have curves, and arabic women appear to be comfortable with having curvy bodies, as has also been reported by others.28 interestingly, the greatest barrier for students was the lack of facilities and their distance, which also agrees with other studies.17,18,29 however, in two of these studies,17,18 both men and women were included, and limited facilities was a common barrier. that is, this appears to be a significant barrier for men as well ; in our study, the students did not clearly disagree regarding whether it was easier for men to be active or that men were more active than women, suggesting that sex differences are not particularly significant. overall, students perceived physical activity positively, just as in other studies.17 however, the overall scores were not associated with physical activity when the students were categorized as active or inactive. this can likely be explained by the fact that positive opinions about physical activity and health in general are not necessarily accompanied by appropriate actions. in other words, a high level of awareness self - efficacy regarding performing physical activities in our study was overall relatively low, requiring further study. self - efficacy was, however, significantly positively associated with physical activity, suggesting that students who were more motivated were more active as well.30 some of the strengths and limitations of the current study need to be considered. a major strength is that this study is the first to provide a considerable amount of information on sociocultural factors related to physical activity among young saudi women. an additional strength is the use of the atls, a validated questionnaire for arab youth and therefore an excellent tool for assessing physical activity and factors related to physical activity in our population. the main limitation of this study is that it involved university students from the capital, who do not represent all students in the ksa or all women of different ages and socioeconomic backgrounds. in addition, the students had health - related study backgrounds, which likely led to their acknowledging the benefits of physical activity. in conclusion, the lack of facilities and lack of encouragement from pnu appear to be the major barriers to greater physical activity in female students. however, there does appear to be sufficient knowledge about physical activity itself and also encouragement from families and social surroundings. in that context, developing more culturally sensitive exercise facilities for women, as well as creating more facilities and implementing university health promotion programs for physical activity would be of great value, at least for educated saudi females. | purposethe kingdom of saudi arabia is experiencing a dramatic increase in physical inactivity, with women having higher levels of inactivity than men among all age groups. it is assumed that factors such as dress codes, restrictions on going outdoors, and conservative norms are the main reasons for women s low physical activity. our aim was to explore the different parameters related to physical activity, including self - efficacy, as well as the perceived barriers to and benefits of physical activity in young saudi females.patients and methodsninety - four first - year female saudi university students in riyadh, kingdom of saudi arabia, participated in the present study in 2014. the students were from eight bachelor s programs in health and well - being, and each completed a questionnaire with questions divided into five parts as follows : 1) socioeconomic status, 2) physical activity, 3) self - efficacy 4) social factors, and 5) barriers and facilitators related to physical activity.resultsthe students exercised at home and alone, and there was low self - efficacy for physical activity (mean score = 4214). among social factors, attending university was the only factor that hindered physical activity (32%). physical activity was positively perceived overall (mean score = 13110). students showed awareness of the benefits of physical activity for health and well - being. the most important barrier was the lack of designated areas available for physical activity. students disagreed that family or the islamic community were barriers to physical activity.conclusionthe lack of facilities and lack of encouragement from the university, but not a lack of knowledge (a high level of knowledge is to be expected given their health and well - being studies backgrounds) and/or restrictions from families and society, seem to hinder female students physical activity, at least young saudi students. |
the 39-year - old female patient visited the hospital as an outpatient, complaining of pains from backache and the right leg. the patient had a lumbar mri scan for back pain at another hospital three years ago, but there was no unusual diagnosis. for pain control, an epidural nerve block was performed at another hospital, but the symptom had not improved yet. after the operation, the patient gradually got pains at the back and right leg, and the symptom became worse starting a year ago. a physical examination showed pains during the silent period, referred pain to the right leg, and radiating pain from the lumbar 5 segment. from the straight leg raising test, the patient complained of pains from both legs at an 80 degree angle. however, any disorder or decompression of motor nerve and sensory nerve was not detected. the lumbar x - ray picture scanned on the same day showed a small metal foreign body (fig. was scanned at the hospital, doctors diagnosed degenerative spondyloisthesis at the lumbar 4 - 5 segment, and degenerative change from the facet joint as well as a foreign body (fig. the hospital diagnosed spinal stenosis and a foreign body at the facet joint, and decided to perform posterior lumbar interbody fusion and foreign body removal from the right facet joint of the lumbar 4 - 5 segment. her liver function examination was normal before operation, except it was positive for the antibody for hepatitis c. except that, there was no special diagnosis before operation. for the treatment before anesthesia, glycopyrrolate 0.2 mg was injected into the muscle on the very day of operation. after arriving at the operation room, 18 g intravenous route was additionally secured at the right side of the upper arm, and an ecg, a noninvasive blood pressure monitor, pulse oximetry, and capnogram were established. for the induction of anesthesia, propofol 2 mg / kg was injected into the muscle for 20 seconds, and after identifying the loss of lid reflex and the stability of blood pressure and pulse rates, rocuronium 0.9 mg / kg was injected into the muscle. after sufficient muscle relaxation was identified after forced breathing with the mask was performed for 2 minutes when there was no spontaneous breathing, intubation was performed. for the maintenance of anesthesia, oxygen 2 l / min, nitrous oxide 2 l / min, and isoflurane 1.5 - 2.0 vol% were used. with the favorable vital signs of the patient, the posture was changed to the prone position, and the surgery was performed after finishing all necessary preparations. the operating surgeon removed the metal foreign body stuck in the right side of the facet joint at the lumbar 4 - 5 segment, and finished the planned posterior lumbar interbody fusion safely. after the operation, the patient recovered well and left the hospital after one week. the foreign body removed from the operation was a stuffed needle with a sloping side made from a metal in silver color ; its diameter was less than 1 mm and its length was 0.7 cm (fig. 3). based on the previous epidural block history of the patient and the shape of the foreign body, it is considered to be the broken stylet of an epidural needle tip. epidural block anesthesia is performed not only for anesthesia of surgical operations but also for pain control after operations and treatment of chronic pains. it is known that its complications rarely occur, but haematoma and spinal nerves injuries, as well as neuromuscular injuries, might break out. once reported that spinal stenosis occurred due to a reactive epidural clot surrounding a catheter fragment which was cut by 1.5 cm in the process of catheter insertion and retained inside the epidural space ; after removing the catheter fragment and injured tissue, symptoms of the patients were improved. reports say that 2 of them required surgical removals while the other did not because no complication was detected. collier described that due to the recent technology development, it is hard to damage an epidural catheter and an epidural block anesthesia needle tip can be broken only with power more than 1 - 2 kg. accordingly, they argued that main culprit of damage is a defect in the process of manufacturing or mistakes of the operating surgeon. reported the case that although a catheter was successfully inserted during a spinal - epidural joint block, a dural puncture was difficult because the needle for spinal anesthesia was short due to the condition of extreme obesity. in that case, the operating surgeon tried spinal anesthesia at the lumbar space one segment lower, but after a number of trials, the spinal anesthesia needle was removed. after the removal, the distant part of the needle disappeared by about 5 cm, and the cut needle tip was removed by performing surgical operation. they reported that the case of the broken needle tip occurred twice in 20 years, showing an occurrence rate of 1 : 5,000. lumbar spinal stenosis is the disease in which the narrowed spine presses the spinal cord. according to kirkaldy - willis., facet joint suffers facet joint syndrome and synovitis from early hypofunction, adding more articular capsules, and the joint becomes unstable so that the vertebral body transfers to the front. repeated stimulus from instability after the transmission causes thickening and osteophyte formation restabilizing spinal segments. however, both thickened structures at the rear and bulging or projecting intervertebral disc at the front suppress the driving region of the nerves, causing spinal stenosis. mostly, the cause of spinal stenosis is a degenerative change of the spine due to aging. for a congenital cause, achondroplasia leads to severe stenosis due to a short pedicle, bulged facet joint, and lamina, and this becomes a cause of early spinal stenosis. also, the spinal stenosis can lead to the second transmutation of spinal stenosis. among secondary causes, moreover, as mentioned earlier, there is a case reported about spinal stenosis occurring by a foreign body inside the vertebral space. the patient in this case is 39 years old, so it is unlikely to be a degenerative spinal stenosis from aging. moreover, while there is no special diagnosis for other spinal segments, an mri scan of the right facet joint in which the needle tip was detected showed a second transmutation including degenerative changes and thickening of the neighboring ligamentum flavum. against the backdrop, it is assumed that the patient had a retained needle tip broken during an epidural block procedure, then the second transmutation occurred around the right facet joint, leading to spinal stenosis. a broken needle tip can occur from a manufacturing problem, rather than from operation techniques. for an ideal needle for epidural block, collier argue that it should be sufficiently sharp to cut spinal ligaments and simultaneously be sufficiently dull so as to not perforate the dural. chin. reported the case when the needle tip and hub of spinal anesthesia injection detached from each other. they assumed that careless manipulation, repeated usages of the spinal needle, and the obesity of the patient were the main culprits, and insisted that an epidural block should be carefully operated under accurate knowledge of anatomy. when facing resistance during the insertion of a needle or catheter for epidural block anesthesia, immoderate proceeds or giving excessive power should be prohibited. also, after finishing an operation, the needle should be checked. the case of spinal stenosis due to the fracture of an epidural block catheter retained inside the epidural space occurred when the tip of the catheter was cut during pulling the catheter back because of resistance in the process of insertion. blanchard. described the case where a patient complaining of radiating pain required a surgical operation due to a retained catheter during the insertion process of a catheter for epidural block anesthesia. introduced the case where the retained catheter was removed through lumbar laminectomy since it was impossible to remove it manually because the catheter was stuck and twisted around the ligamentum flavum. in most cases, however, a catheter being retained inside the epidural space does not cause problems. if part of the catheter during epidural block anesthesia is retained inside patients, it is not normally removed. for rare cases accompanying neurologic symptoms or second transmutations, surgical operations might be required. when operating epidural block anesthesia, accurate knowledge of anatomy should be a prerequisite to avoid careless manipulation. also, operators should check whether the tip of needle or catheter is broken or not with the naked eye, and when the retained fracture is doubtful, they should consider x - ray scanning. so far, there have been reports about spinal stenosis due to retained fracture of a catheter inside the vertebral space. however, there is none about the case describing spinal stenosis from retained catheter fracture inside the spinal space. | lumbar epidural anesthesia is useful in a variety of chronic benign pain syndromes, including lumbar radiculopathy, low back pain syndrome, spinal stenosis, and vertebral compression fractures. given the increased number of epidural nerve blocks being performed, some have reported unexplained complications of a transient or permanent nature and with varying degrees of severity. however, no case has been reported of a broken epidural needle tip retained in the lumbar facet joint area. this represents the first reported case presentation of foraminal stenosis developing in a patient after a retained epidural needle tip. |
patients who were treated with intravitreal injections of anti - vegf agents for wet amd or dme before may 1, 2013, were selected for review of their medical records. any patient with rvo was excluded as well as any patient younger than the age of 40 years. patients in this study received between 1 and 20 intravitreal injections and iop measurements were performed with a tonopen (haag - streit, cincinnati, ohio, usa). the average age of patients receiving injections was 75.5 years, and the average age of control patients was 68.5 years. iop measurements were followed over time for as long as data were available before may 1, 2013. the range of follow - up across all patients was between 6 months and 10 years. iop measurements were stratified according to how many months after the first injection, the measurement was taken. the following time points were used for stratification : 06 months, 612 months, 1218 months, 1824 months, and 24 + months after the first injection. in addition, patients were stratified by total number of injections received per eye : 13 injections (n = 33 for dme, n = 29 for amd), 46 injections (n = 18 for dme, n = 22 for amd), 79 injections (n = 6 for dme, n = 8 for amd), and 10 + injections (n = 17 for amd). a total of 76 eyes with amd and 55 eyes with dme were included in the study. one set of controls comprised two patient types : diabetics (either without ocular complications or only with nonproliferative diabetic retinopathy) or dry amd. this control group included 125 eyes, and its purpose was to characterize any change in iop that may occur in these chronic conditions over time. the second set of controls was patient who only received unilateral injections. by using the noninjected eye as a control eye and comparing iop over time, we minimized the number of variables both known and unknown that affect iop. this control group included 72 eyes, and its purpose was to detect iop changes that could be attributed with more certainty to the intravitreal injections received. intravitreal injections of either ranibizumab (0.5 mg/0.05 ml or 0.3 mg/0.05 ml), bevacizumab (1.25 mg/0.05 ml) or aflibercept (2.0 mg/0.05 ml) were administered at our institution using an aseptic technique after the administration of topical anesthesia. tetracaine drops and cotton - tipped applicators soaked in 4% lidocaine chloride were applied to the superotemporal conjunctival surface. ten percent of the povidone - iodine solution was then applied to the injection site and allowed to dry for approximately 60 s before administration of the intravitreal injection. ranibizumab and aflibercept were drawn up using a filtered needle immediately before use. a lid speculum and nonsterile gloves after injection, two drops of moxifloxacin hydrochloride ophthalmic solution (vigamox, alcon, fort worth, tx, usa) were applied. the scheduled regimen for the various anti - vegf agents varied from patient to patient depending on disease state, aggressiveness of condition, visual status of the other eye, and patient ability to return for repeated injections. in general, if optical coherence tomography confirmed resolution of intraretinal and subretinal fluid and clinical examination did not show macular subretinal fluid and/or hemorrhage (in wet amd patients), then the treatment interval was extended by 12 weeks. if fluid or hemorrhage recurred, the interval was shortened. no prophylactic therapies for iop elevation (e.g., the use of iop - lowering eye drops, ocular compression, or anterior chamber paracentesis) were performed before or after intravitreal injection. central retinal artery perfusion was assessed following injection by confirming a minimum vision of hand motion. patients with glaucoma were asked to not use their glaucoma drops in the injected eye the night of the injection but to resume the following day. the following variables were recorded for each patient : age, sex, diagnosis, baseline iop, iop measurement before each injection, refraction, injection dates, total follow - up period, glaucoma history, total number of anti - vegf agent injections, and anti - vegf agent administered. as mentioned above, patients were grouped according to diagnosis (dme vs. wet amd) and number of injections received. the univariate, one - tailed t - test was performed to test the null hypothesis that iop does not change over time as a result of receiving intravitreal anti - vegf injections. patients who were treated with intravitreal injections of anti - vegf agents for wet amd or dme before may 1, 2013, were selected for review of their medical records. any patient with rvo was excluded as well as any patient younger than the age of 40 years. patients in this study received between 1 and 20 intravitreal injections and iop measurements were performed with a tonopen (haag - streit, cincinnati, ohio, usa). the average age of patients receiving injections was 75.5 years, and the average age of control patients was 68.5 years. iop measurements were followed over time for as long as data were available before may 1, 2013. the range of follow - up across all patients was between 6 months and 10 years. iop measurements were stratified according to how many months after the first injection, the measurement was taken. the following time points were used for stratification : 06 months, 612 months, 1218 months, 1824 months, and 24 + months after the first injection. in addition, patients were stratified by total number of injections received per eye : 13 injections (n = 33 for dme, n = 29 for amd), 46 injections (n = 18 for dme, n = 22 for amd), 79 injections (n = 6 for dme, n = 8 for amd), and 10 + injections (n = 17 for amd). a total of 76 eyes with amd and 55 eyes with dme were included in the study. one set of controls comprised two patient types : diabetics (either without ocular complications or only with nonproliferative diabetic retinopathy) or dry amd. this control group included 125 eyes, and its purpose was to characterize any change in iop that may occur in these chronic conditions over time. the second set of controls was patient who only received unilateral injections. by using the noninjected eye as a control eye and comparing iop over time, we minimized the number of variables both known and unknown that affect iop. this control group included 72 eyes, and its purpose was to detect iop changes that could be attributed with more certainty to the intravitreal injections received. intravitreal injections of either ranibizumab (0.5 mg/0.05 ml or 0.3 mg/0.05 ml), bevacizumab (1.25 mg/0.05 ml) or aflibercept (2.0 mg/0.05 ml) were administered at our institution using an aseptic technique after the administration of topical anesthesia. tetracaine drops and cotton - tipped applicators soaked in 4% lidocaine chloride were applied to the superotemporal conjunctival surface. ten percent of the povidone - iodine solution was then applied to the injection site and allowed to dry for approximately 60 s before administration of the intravitreal injection. ranibizumab and aflibercept were drawn up using a filtered needle immediately before use. a lid speculum and nonsterile gloves were used during the injection procedure. after injection, two drops of moxifloxacin hydrochloride ophthalmic solution (vigamox, alcon, fort worth, tx, usa) were applied. the scheduled regimen for the various anti - vegf agents varied from patient to patient depending on disease state, aggressiveness of condition, visual status of the other eye, and patient ability to return for repeated injections. in general, if optical coherence tomography confirmed resolution of intraretinal and subretinal fluid and clinical examination did not show macular subretinal fluid and/or hemorrhage (in wet amd patients), then the treatment interval was extended by 12 weeks. if fluid or hemorrhage recurred, the interval was shortened. no prophylactic therapies for iop elevation (e.g., the use of iop - lowering eye drops, ocular compression, or anterior chamber paracentesis) were performed before or after intravitreal injection. central retinal artery perfusion was assessed following injection by confirming a minimum vision of hand motion. patients with glaucoma were asked to not use their glaucoma drops in the injected eye the night of the injection but to resume the following day. the following variables were recorded for each patient : age, sex, diagnosis, baseline iop, iop measurement before each injection, refraction, injection dates, total follow - up period, glaucoma history, total number of anti - vegf agent injections, and anti - vegf agent administered. as mentioned above, patients were grouped according to diagnosis (dme vs. wet amd) and number of injections received. the univariate, one - tailed t - test was performed to test the null hypothesis that iop does not change over time as a result of receiving intravitreal anti - vegf injections. the first division of patients involved grouping them by disease condition : wet amd or dme. 1 shows the iop measurements over time in wet amd eyes based on number of injections received. in each subset of eyes (13 injections, 46 injections, 79 injections, and 10 + injections), there was no statistically significant increase in pressure at any time point, when compared to the baseline iop, represented as the cumulative average iop before injections began. intraocular pressure measurements over time in patients with wet age - related macular degeneration intraocular pressure over time in patients with wet age - related macular degeneration fig. 2 shows the iop measurements over time in dme eyes based on number of injections received. similar to the wet amd patients, in each subset of eyes, there was no statistically significant increase in pressure at any time point when compared to the iop before injections began. the p values obtained in this analysis are listed in table 2. intraocular pressure measurements over time in patients with diabetic macular edema intraocular pressure over time in patients with diabetic macular edema fig. 3 summarizes the iop over time of patients who only received injections to one eye. only the subgroup undergoing 79 injections showed an increase in iop, but that increase was not statistically significant. the other groups showed a decrease in iop in the injected eye at the end of the evaluation period (may 1, 2013). unilateral injections : comparing treated eye to control eye unilateral injections : comparing treated eye to control eye finally, an analysis of 115 control eyes was performed. patients from the control group carried a diagnosis of either diabetes mellitus (without proliferative diabetic retinopathy or macular edema) or dry amd, and their eyes did not require anti - vegf injections. the mean baseline iop was 16.0, and the mean iop after 2 years of follow - up was 15.6 (p = 0.10), which was not significantly different than baseline. the purpose of our study was to determine whether intravitreal anti - vegf injections used for wet amd or dme result in a sustained increase in iop, a controversial topic within the vitreoretinal community. the first was to analyze patients who received unilateral injections with the noninjected eye serving as the control eye and measure the difference in iop between the injected and noninjected eyes at the end of the evaluation period. the second was to divide all injected eyes by indication (wet amd or dme) and to measure iop over time within different categories (number of injections received). in all cases the first papers investigating iop elevation after intravitreal anti - vegf agents were published in late 2007 and looked at short - term effects on iop. the previous studies had already shown that short - term iop elevations occurred after intravitreal triamcinolone acetonide injections, and the safety of intravitreal anti - vegf injections became fundamentally important as their use had increased exponentially. studies by falkenstein. and hollands. showed a transient spike in iop that was presumably due to the increased intraocular volume after injection. however, iop returned to baseline after the respective follow - up time (15 min and 30 min)., investigating ranibizumab and bevacizumab, respectively, confirmed a spike in iop shortly after injection but continued to monitor patients after injections. despite an increased iop at 30 min, neither of these studies found a significant difference between pre- and post - injection iop at future follow - up visits. they concluded that intravitreal injections of ranibizumab and bevacizumab seem to be safe from an iop standpoint in the short - term, and that iop monitoring may not be necessary after injections. a study by bakri. was the first to show a sustained increase in iop after intravitreal anti - vegf injections ; they published a case series of four patients with persistent elevation of iop after ranibizumab injections. none of the patients had any identifiable risk factor, and the elevated iop was controlled in all eyes with medical therapy. a number of case series have been published since identifying a subset of patients experiencing a sustained elevation of iop after ranibizumab and/or bevacizumab injections. these cases supported the need for further studies investigating the incidence of sustained elevated iop after intravitreal anti - vegf injections. the recent studies have shown conflicting results concerning the existence of sustained iop elevation after injections. he described a series of 25 eyes experiencing sustained iop elevation after ranibizumab and/or bevacizumab injections, and two retrospective studies finding that a greater number of injections was associated with increased risk for iop elevation. one of these studies found that 7.1% of eyes experienced sustained iop elevation, while the other found this value to be 11.6% in treated eyes versus 5.3% in untreated eyes. despite numerous studies describing a subset of patients with sustained iop elevation, we found three studies that found no correlation between intravitreal injections and sustained iop elevation. rates of sustained iop elevation were found to be 3/270 injected eyes (0.5% incidence) and 20/629 (3.2%) in studies by brucker and yoon, respectively. kim. measured average iop at baseline and after 6, 12, 18, and 24 months and found no significant increase of iop during the follow - up period. the recent extensive literature on the topic has produced a wide range of results. while it has been consistently shown that injections cause a short - term spike in iop, most early papers saw this spike return to baseline and found no evidence of a sustained iop elevation. however, a number of studies have found that a low percentage (ranging from 3.0% to 11.6%) of eyes experience a sustained increase in iop. some potential risk factors identified in these studies include male gender, short duration of time between injections, higher number of total injections, and history of glaucoma. other studies have found no increased risk of sustained iop elevation compared to noninjected eyes. it should be noted that although most studies cited by this paper specifically investigated ranibizumab and bevacizumab, our clinic began also using aflibercept in 2011. there is currently no evidence to suggest that any of these three treatments are more likely than the other to cause an increase in iop. it is clear that more research is needed on the topic, particularly in identifying risk factors that may put patients at increased risk for sustained iop elevation. while many possible mechanisms have been proposed for iop elevation after anti - vegf injections, none have been proven. our data are consistent with other studies that have failed to show an effect on iop when using mean iop as the metric to measure change over time. our data suggest that a treat - and - extend dosing regimen for anti - vegf intravitreal injections is not a significant risk factor for an increase in iop, regardless of how many injections the patient receives. clinicians should use anti - vegf agents with the confidence that long - term iop elevations are of minimal concern and routine evaluation specifically for iop elevation may not be necessary. dr. hariprasad is a consultant for alcon, allergan, bayer, od - os, clearside biomedical, ocular therapeutix, janssen, leica, spark, and regeneron. dr. hariprasad is a consultant for alcon, allergan, bayer, od - os, clearside biomedical, ocular therapeutix, janssen, leica, spark, and regeneron. | objective : there is a substantial debate in the ophthalmology community about whether anti - vascular endothelial growth factor (vegf) injections result in a long - term increase in intraocular pressure (iop).design : we performed a retrospective study to investigate how the number and timing of intravitreal injections in patients with age - related macular degeneration (amd) and diabetic macular edema (dme) affect iop over time.methods:we collected long - term iop data on patients receiving anti - vegf injections at our institution. patients over the age of 40 years who received injections for amd (n = 76) or dme (n = 55) were included. patients were grouped according to indication as well as number of injections received (13, 46, 79, or 10 + injections). iop measurements were then placed into time points (06, 612, 1218, 1824, or 24 + months) and compared to the preinjection average iop.results:for patients with dme, average preinjection iop was 15.7 mmhg. at 24 + months after injection, the average iop was 15.2 (p = 0.68) for patients receiving 13 injections, 16.8 (p = 0.23) for 46 injections, and 14.4 (p = 0.66) for 79 injections. for patients with amd, average initial iop was 15.6 mmhg. at 24 + months after injection, the average iop was 12.6 (p = 0.97) for 13 injections, 14.9 (p = 0.96) for 46 injections, 14.8 (p = 0.84) for 79 injections, and 15.7 (p = 0.56) for 10 + injections.conclusions:there was no increase in iop over time for amd or dme patients, regardless of how many injections they received. for patients receiving unilateral injections, there was no increase in iop in the injected eye when compared to the noninjected eye. |
epidemiological studies suggest an association between exposure to diesel emissions and an increased incidence of lung and bladder cancer in humans. of the compounds associated with diesel emissions, 1,6-dinitropyrene is a particularly potent mutagen and carcinogen. in these experiments we administered [4,5,9,10 - 3h]1,6-dinitropyrene (30 or 100 micrograms) directly to the lungs of f344 rats according to a protocol known to induce lung tumors and characterized the dna adducts present in the target tissue. in addition, we examined the adducts present in spleen lymphocytes and assayed for the induction of mutations at the hypoxanthine - guanine phosphoribosyltransferase locus in these cells, as measured by the frequency of 6-thioguanine - resistant (tgr) t - lymphocytes. adduct formation was detected in both lung and spleen lymphocyte dna, with the extent of binding being dose - dependent in the lymphocytes but not the lung. 32p - postlabeling analyses indicated the formation of a major dna adduct, n-(deoxyguanosin-8-yl)-1-amino-6- nitropyrene, in both tissues. 1,6-dinitropyrene treatment resulted in a dose - dependent increase in tgr t - lymphocytes, with the increase being detected for at least 21 weeks after treatment. these data indicate that 1,6-dinitropyrene is metabolically activated by nitroreduction to form dna adducts in both the target tissue and spleen lymphocytes and that a tumorigenic dose results in a significant induction of tgr t-lymphocytes.imagesfigure 2. |
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penile cancer is a rare malignancy (0.58/100.000 men) in the developed countries. in the authors own country, with its population of 36 million, 232 new cases and 89 new deaths were recorded in 2010. these rates are comparable with those recorded elsewhere in western europe, but much lower than in africa, south america and asia. the primary treatment for penile cancer is surgery, although in the case of precancerous changes or in cancer detected at an early stage, minimally invasive clinical methods such as superficial chemotherapy, laser therapy or brachytherapy may be applicable. surgical treatment involves the removal of the primary tumor lesion with or without performing inguinal lymphadenectomy, depending on clinical indications or the histopathology of the original change. the surgical procedure involves removing the change itself, that is, the re - sectioning of the lesion, circumcision, glansectomy and the partial or total amputation of the penis, subsequently forming an exit for the urethra into the perineum. guided by experience and/or intuition alone, each urologist describes the total amputation of the penis as a most debilitating procedure, which clearly adversely affects the patient 's quality of life, particularly one 's sex life. the quantity and quality of data available in the medical literature to substantiate such predictions is scarce, which significantly limits the quality of the publication. however, one should bear in mind that penile carcinoma is a rare disease and there is only a limited pool of patients available for clinical research. for this reason, various tools are used and they are often not validated, making comparison of any results difficult. due to the limitations presented above, the study of the disease should be carried out solely in specialist reference hospitals. this would give easier access to a larger number of patients, thereby facilitating prospective research. the study included patients treated during the period 06.2007 to 06.2013 at the uro - oncology department, memorial cancer centre, warsaw, poland all underwent total amputation with perineal urethrostomy. simultaneous inguinal lymphadenectomy, along with surgery of the penis did not disqualify the patient from taking part in the study. the study was carried out with the consent of the local bioethics committee (kb-411 - 3 - 13). for the assessment of the quality of life, cancer - specific instruments were used as a major research tool together with modular questionnaires assessing some selected aspects of the quality of life. rated parameters were taken into account such as age, education, place of residence, employment status, marital status and partnership relations for which the author developed the question : how would you rate satisfaction in your relationship with your partner : 1 not at all satisfactory, 2 almost satisfactory, 3 satisfactory on average, 4 very satisfactory. for an overall assessment of the quality of life, european organisations for research and the treatment of cancer (eortc) -qlq - c30 v 3.0 questionnaire was used. modular questionnaires were used as tools to assess self - esteem, the patient 's sexual life, masculinity and symptoms associated with the lower urinary tract. the level of the self - rated questionnaire was assessed with the help of the rosenberg self - esteem scale (ses). the scale consists of 10 statements regarding positive or negative conscious attitudes to the inner self and the emotions, associated with cognitive opinions about oneself. the percentage score was arbitrarily categorised into five groups from very low self - esteem to very high self - esteem. for the assessment of a patient 's compliance or non - compliance with masculinity standards, the conformity to masculine norms inventory (cmni) questionnaire was used [10, 11 ]. the questionnaire consists of 22 questions reflecting 11 domains of the i d in the perception of masculinity norms, in areas such as indomitability (or the unwillingness to be beaten), emotional control, risk - taking, violence, control of women, domination, the playboy behaviour independence, the over - riding importance of work, disdain for homosexuality and the pursuit of status. each question has four answers on a scale from 0 to 4 points (from strongly disagree 0 points to strongly agree 4 points). the results were arbitrarily divided into five ranges from very low compliance to very high compliance. in order to assess the sexual sphere, a modification of the international index of erectile function (iief-15) was developed [12, 13 ]. based on conversations between the cancer survivors and urologists experienced in this area, sexual activity was defined, for the purpose of this study, as the stimulation of selected parts of the patient 's body, visual stimulation providing sexual satisfaction as well as contact with the so - called inter alia, of such areas as the pubic symphysis, anus, scrotum, testes or nipples. the so - called ' open field in the questionnaire was left to allow inclusion of other areas, the touching of which is identified with sexual activity. in the next question, the duration (in minutes) of a single the next question came from the iief-15 questionnaire from question 7 to question 15 and related to the respective domains of satisfaction obtained from sexual activity. the term sexual activity. all answers to the questions were to reflect the patient 's status in the last 6 months. in order to assess the symptoms associated with the lower urinary tract (luts), the international prostate symptom score (ipss) questionnaire was used [14, 15 ]. the mann - whitney u test was used in order to compare the results obtained from the individual questionnaires with respect to age, education, size of city, employment status, satisfaction in the relationship with a partner and marital status. a significance level of p of the 24 patients who underwent total amputation of the penis, between 01.2009 and 08.2013, 13 patients died due to progression of the original disease. the remaining 11 patients were sent questionnaires in october 2013 concerning their quality of life. of this group, responses from 10 patients were obtained and subjected to further analysis. the average age of the patients was 60 years, with ages ranging from 35 to 74 years and the median being 60.5 years. the median time elapsed from the treatment to the present investigation was 16 months (range from 7 to 49 months). socio - demographic data table 2 presents the patients clinical and pathological characteristics. within the group of patients (6 ptn) remaining in the same relationship, at the time of surgery, 4 patients reported no deterioration in their personal relationship, whereas in one case, the relationship actually improved. among all patients after surgery, 2/10 patients established new partnerships, while two - thirds remained with the same partner. the median result of the ses self - assessment questionnaire was 75%, but ranged, however, from 67% to 87%. the average level of self - esteem was shown, in 1/10 of the patients, to be high and very high, with scores of 90% and 100%, respectively. the median result for compliance with masculinity norms compliance with standards of masculinity was very high in all patients (30% of patients high compliance ; 70% of patients very high compliance). the median result for the ipss questionnaire was 12.5 points, ranging from 11 to 18 points. patient 's clinico - pathological characteristics lnd superficial inguinal lymphadenectomy and a deep one on both sides the majority of patients responded to the question regarding their sexual life, by saying that they were not sexually active ; these patients did not respond to specific questions. two patients defined touching the pubic symphysis area, at the scars of the penis, as sexual activity. in addition, one of these patients defined sexual activity as manual stimulation, such as touching and fondling, around the anus, the scrotum, and the breasts. in two other patients from this group, responses to questions from the original iief-15 questionnaire wherein the phrase sexual intercourse was modified to most patients did not experience orgasm and ejaculation during sexual activity. sexual relations with a partner were defined as very unsatisfactory by the majority of patients ; however, one patient described these relations as very rewarding. the median for the domain of the global health status / qol eortc c-30 questionnaire was 50. the median results for other domains of the questionnaire, as well as the results of the reference eortc quality of life group for the relevant cancer, are presented in table 3. the median result for individual domains of the qlq c-30 questionnaire and the results of the reference eortc quality of life group for the relevant cancer statistical analysis of the results obtained from the individual questionnaires, with respect to age, education, place of residence, employment status, partner relationship and marital status, revealed some important relationships. statistically significant differences were found in the results of the qlq c-30 questionnaire relating to the role - function domain, in relation to age (p = 0.008) and level of education (p = 0.032) ; then in the qlq c-30 questionnaire, relating to the domains of emotional function, in relation to education level (p = 0.008) and finally in the qlq c-30 questionnaire relating to the domains of physical functioning vis - - vis partnership relationships (p = 0.032) long - term survival in patients after penile cancer treatment may be associated with sexual dysfunction, voiding and cosmetic problems, penile appearance, all of which may adversely affect the patient 's quality of life [17, 18 ]. in particular, this applies to the most debilitating method of treatment which is total amputation of the penis. a systematic review of the literature by meddineny. on the quality of life, vis - - vis psychosexual and psychosocial terms, in patients with penile cancer, subjected to different treatment methods, including total amputation of the penis, revealed only 6 related studies. the above - cited authors showed that the treatment of penile cancer has a negative impact on the well - being of up to 40% of patients and that the more disabling the treatment, the more likely it is to impair patient well - being. the authors also point out that in these 6 studies, 13 different, quantitative tools were used to assess psychological well - being, qol and sexual function. a significant problem is the lack of standardised research tools for assessing qol in this group of patients. most of the research studies have used data collected retrospectively from a small group of patients in single medical centres using different measurement methods. one of the most common tools used in the hrqol assessment of cancer patients is the eortc - qlq c-30 questionnaire. many uro - oncological research studies have used this tool under the assumption that assessing the quality of life is one of the main reasons for using this tool [20, 21, 22 ]. the eortc group was developed to measure disease and treatment - related qol issues relevant to selected uro - oncological diseases, such as cancers of the prostate, bladder and testicule, not covered by the eortc qlq - c30 [2225 ]. however, a module dedicated to patients with cancer of the penis has not been developed as of yet. in our study, the median global health assessment / quality of life in the eortc qlq - c30 questionnaire was lower than in the general population and in genitourinary cancer patients. in addition, the median of all five functioning domains, including physical functioning, role functioning, emotional functioning, cognitive functioning, and social functioning, were lower compared to general population reference values. in the domain of physical functioning, the median result in patients after complete amputation of the penis, was also lower than in the male population suffering from various other cancers, including bladder cancer. a statistically significant difference was observed in the score of physical functioning in relation to partnership relations. this suggests that patients, who were more satisfied with their relationship with a partner, evaluated their physical functioning more highly. the median results among respondents for the role functioning domain was higher than in the population of genitourinary cancer patients and bladder - cancer patients. it was noted, however, that there is a statistically significant correlation between age (p = 0.008) and education (p = 0.032). younger and better - educated patients rated their functioning lower. in reference to this observation, it should be noted that the average age for disease onset in our study group was 60, which could have resulted in the higher scores observed in the role - functioning domain. in our study, the median result for the emotional functioning domain, for patients undergoing total amputation of the penis, was lower than in the population of patients with various cancers and bladder - cancer. a statistically significant difference was observed in the score of emotional functioning in relation to education (p = 0.008). the more educated patients assigned a lower score to this aspect, which also included their subjective evaluation. in connection with the results obtained on the overall quality of life, measured by the eortc c-30 questionnaire, it is advisable to take, under special psychological care, those patients who are not in a satisfactory relationship with their partner and also younger and highly - educated patients should these patients be placed under such special care, there could well be a lesser decline in qol after surgery. of all urogenital cancers, penile carcinoma is the cancer, which most evidently jeopardises sexual function. it seems that the sex life of patients undergoing total amputation will suffer the greatest as it is the most debilitating of surgical procedures. in the questionnaire conducted by opjordsmonem. in which they asked doctors for their views on sexual activity among patients undergoing total amputation of the penis, sexual interest in these patients was assessed as severely reduced. showed that patients had moderate sexual function scores with a mean of 2.1 (4 = best function ; 0 = worst function) across all treatment groups, but those patients who had undergone more radical treatment had lower scores (1.3 and 1.0 for partial and total penectomy, respectively). although the eortc qlq - c30 is a psychometrically robust hrqol measuring tool for the generic cancer population, it is not aimed at detecting specific hrqol aspects related to different carcinomas, such as sexual function and urinary problems. so far, a questionnaire, specific for penile cancer, which deals with these aspects of quality of life, has not been developed. in evaluating the sexual sphere, most authors have used a variety of research tools and self - developed questionnaires [19, 26, 2831 ] (table 3). to date, no specific tool facilitating the analysis of sexual function in patients undergoing total amputation of the penis has been developed. the iief-15 questionnaire seems to be a valuable tool for assessing the domain of sexual life. it has been used, inter alia, to evaluate the qol of patients after, organ - sparing surgery, partial amputation and laser treatment [3134 ]. in order to assess sexual life, the present authors have developed their own tool, which is a modification of the iief-15 questionnaire. in the interest of presenting the issue attention should be drawn to the fact that the average age of the patients, which was 60, could have affected the results of the evaluation of the sexual sphere. similar conclusions have been drawn by opjordsmoean., who analysed four patients after complete amputation of the penis [19, 26 ]. to evaluate the sphere of sexual life, the above - mentioned authors applied, at the time of surgery, a global score of overall sexual function. qualitatively, patients indicated that their condition would have had a greater impact on their sexual function and quality of life, had they been younger. however, this correlation is not obvious, as evidenced by one of the patient 's responses in this study : i think there 's far more to being a human being and far more to being a man than just simply being dependent on a penis. in our study, both sexual activity and sexual desire were evaluated more critically by the patients. using the same tool, namely the iief-15 questionnaire, different results were obtained when examining patients after partial amputation of the penis, where dysfunction concering sexual desire was assessed as mild. such discrepancies among patients, after total and partial amputation of the penis, are most likely caused by the more debilitating scope of the operation, which may have a significant impact on the change in the patient 's understanding of oneself, their masculinity and sexual desires. it should also be noted that if a man is willing to put some effort into his sex life, pleasure is possible after amputation of the penis. total penectomy patients report that stimulation of their remaining genital tissue, including the mons pubis, healed surgical site, perineum and scrotum, produces an orgasm. the patients in our study regarded their sexual activity similarly. touching the area of the pubic symphysis at the site of the scar or the perianal scrotum, or breast stimulation was, for them, equivalent to sexual activity. although most patients did not undertake any sexual activities and evaluated their sexual relations with their partner as very unsatisfactory, it should be noted that the overall relationship, for most patients, was good, since 85% of the patients claimed that the relationship with their partner had not deteriorated, while one patient found that his relationship with his partner had actually improved. moreover, it is an interesting fact that despite the total amputation of the penis, 2/10 of patients, who were single at the time of the surgery, established new partnerships post - operatively. the authors have no data as to the period of time, which had elapsed between surgery and the formation of new relationship. the above data suggests that in selected patients, the impairment of the sexual domain does not necessarily have a negative impact on the overall relationship with a partner., in which several patients said that their own lack of sexual gratification was less of a concern than were their feelings of being unable to satisfy their partner. one of the patients said : " me and my wife never make love anymore ; it 's her i feel sorry for really ". an important issue raised by many studies carried out in patients with cancer of the penis after radical surgery, is the concept of masculinity [18, 30, 31, 35 ]. masculinity is a socially- constructed expectation that embraces a set of norms and behaviours that are expected to be exhibited by men. these norms and beliefs can be influenced by environmental factors, as well as by social and cultural beliefs. men not complying with these expectations have been viewed as subordinate and weak. of the many expectations of a masculine man, his sexual prowess and his ability to satisfy a partner are crucial qualities [52, 53 ]. illness can reduce a man 's status in masculine hierarchies, shift his power relations with women and raise his self - doubts about his own masculinity. this study made use of the cmni which has been psychometrically tested. despite the use of severely debilitating treatment in all patients, compliance with the standard of masculinity was high or very high. the impact on masculinity has also been studied in patients after partial amputation of the penis and the conclusions drawn were convergent. some aspects of sexuality, such as masculine self - image and the relationship with one 's partner, remained basically unchanged. an important element of qol is emotional function and social self - esteem and, in turn, self - esteem which has a significant effect on these parameters. rosenberg., demonstrated a correlation between low self - esteem and depression. the above - mentioned author pointed out that the feeling of being of lesser value is a characteristic symptom of neuroses. the present authors used a simple, self - assessment scale (ses), in evaluating a positive or negative attitude towards the i d in their own study. no patient defined his self - esteem as low, while 9/10 of patients defined their level of self - esteem as high. perhaps a significant impact on such high self - esteem was the fact that more than three - quarters of patients reported that the relationship with their partner, with had been already established at the time of cancer diagnosis, had not deteriorated. two patients from the whole group established new relationships with a partner after surgery, which could also prove the significance of high, self - definition as being good enough for formation of new partnerships, quite regardless of the total amputation of the penis. where, among those patients studied, most remained in partnered relationships while subject to different methods of penile cancer treatment. the present author emphasises that the overall positive results with regard to hrqol and survival issues, partly reflect that having a good relationship was reported to be an important, protective factor against feelings of anxiety after surgery. the positive effect of a partner on sexual rehabilitation has been emphasised in other studies involving uro - oncological patients [20, 21, 38 ]. in the study by bullen. the centrality of wives or female partners, in providing support, was a key finding. the data suggested that rehabilitation was possible for men in strong, supportive relationships, which provided reassurance of a continued, albeit re - constructed, masculine role. conversely, for those without this support, successful rehabilitation was less likely. the appropriate time period that should elapse from the performance of penis surgery to conducting the qol assessment has not been clearly defined. bullen. evaluated an adaptation period of a minimum of 18 months, post - surgery, within the range from 18 months to 5 years. in the present study, the number of patients in the present study was small and any comparison with other studies must be made with caution. it should be appreciated, however, that penile cancer is a rare malignancy and the group under investigation is significantly large, compared to previous studies in which a group of four patients, following total amputation, was surveyed with respect to an assessment of their quality of life and sexuality [18, 19, 28 ]. it must be noted that when researching rare conditions, the sampling rationale is reversed ; rather than aiming to recruit a sufficient number of participants to achieve data saturation, the goal should be to work out how best to use the information gathered, given recruitment limitations. we should assume that the lack of a control group was a drawback to our study. even though sexual impairment after penile amputation is self - evident, other known circumstantial changes related to oncologic surgery may also play a role. one undoubted drawback of our study is its retrospective nature. supplementing this study with a qol assessment, before surgery, could extend the possibilities for data analysis and increase credibility of the results, especially in the sexual sphere. it should be emphasised that our study is the first survey dedicated entirely to patients having undergone complete amputation of the penis. by developing our own assessment tools of the sexual sphere, as well using other, recognised research tools relating to qol the results obtained indicate that total amputation of the penis significantly affects the sexual sphere of life as well as the overall quality of life. however, it should be noted that this does not have negative implications in terms of partnership relations, self - assessment or the evaluation of masculinity. the results obtained indicate the need for further exploration of this issue to determine coping strategies for patients. it is important that psychologists, trained in sex therapy and other dedicated specialists, begin working with the patient while treatment is being decided. future studies on large and perhaps international samples, a prospective research design, standardised measurement tools and normative comparison groups can help to further clarify the problem of the quality of life and the sexual sphere in patients after total amputation of the penis and the perceived needs of men with penile cancer. | introductiontotal amputation, as a treatment for advanced penile cancer, significantly debilitates the patient 's quality of life and sexual function. the aim of the study was to assess the quality of life in patients who had undergone total penectomy.material and methodsthe questionnaires eortc qlq c-30, ses, cmni, and a modified iief-15 questionnaire, were sent to 11 patients.resultsa total of 10 patients returned the questionnaires completed. the results of the overall quality of life, the median result in individual domains, as assessed by the eort qlq c-30 questionnaire, were clearly lower than the reference results. there were statistically significant differences in the results of the qlq c-30, concerning the role - functioning domain in relation to age (p = 0.008) and education (p = 0.032), in the domain of emotional functioning in relation to education (p = 0.008) and in the domains of physical functioning in relation to the partner relationship (p = 0.032). a significant number of patients were sexually inactive. sexual activity as defined by touching the area of the pubic symphysis at the scars of the penis, touching and fondling perianal areas or the scrotum and watching things / people that cause excitement was observed in 2/10, 1/10 and 2/10 of patients respectively. in 5/6 of these patients, partnership relationships did not deteriorate, including one patient for whom the relationship actually improved.conclusionsthe results obtained indicate that total amputation of the penis significantly affects one 's sex life and overall quality of life. however, this does not have negative implications in terms of partnership relations, self - assessment or the evaluation of masculinity. |
diabetes mellitus (dm) comprises a group of metabolic diseases characterized by hyperglycemia, resulting from insulin disturbance. the prevalence of diabetes is increasing worldwide and varies depending on age and race. although increased number of new patients is diagnosed with diabetes, the seriousness of diabetic complications is not fully appreciated yet. approximately 85 - 90% of diabetic cases are diagnosed with type 2 diabetes and results from insulin resistance. altered insulin production and insulin resistance state in type 2 diabetics cause impairment of metabolic balance and uncontrolled or poorly controlled diabetes in their health status is associated with increased susceptibility to oral infections and poor wound healing. high risk of dental caries resulting from salivary dysfunction such as xerostomia,1 a greater likelihood of oral mucosal disorders such as lichen planus, recurrent aphthous stomatitis and candidiasis was reported.2 - 4 also, some studies have reported that diabetic patients had more denture stomatitis and candidiasis than non - diabetics.5,6 diabetic patients may have abnormal modifying factors in soft tissue and these soft tissue manifestations should be perceived in diabetic patients who require teeth and prosthetic restorations. diabetic patients are more susceptible to tooth loss than non - diabetic patients due to higher risk for periodontitis. epidemiologic researches suggests that diabetes increases the risk of periodontal disease, resulting in increased severity of periodontitis.7,8 the relationship among diabetes mellitus, periodontal state, and subsequent tooth loss has also been reported. a case - control study showed that type 2 diabetics had a significantly lower number of teeth present9 and a study of prognostic model for tooth survival suggested diabetes mellitus as a significant indicator for tooth loss10 there is ample evidence of the biological and epidemiological association between periodontal disease and diabetes, especially, type 2 diabetes mellitus.11,12 the influence of diabetic condition on periodontium and oral manifestations has been reported in several articles. an explanation for increased infection susceptibility of diabetic patients is that impaired chemotaxis and defective phagocytosis or impaired adherence were caused by polymorphonuclear leukocyte (pmn) deficiencies. moreover, the increased severity of periodontal disease in diabetic environment may reflect an alteration in the pathogenic potential of bacteria13 and increased expression of marker of systemic inflammation such as circulating c - reactive protein (crp), enhancing a breakdown of periodontal tissues, resulting in more frequent and severe periodontal - tissue destruction.14 several articles reported that mechanisms underlying the advanced periodontal disease associated with diabetes appear to reflect abnormal host responses.15 - 18 such relationship is similar to the relationship between glycemic control and the classic complications of diabetes mellitus ; nephropathy, retinopathy and altered wound healing. in this way, diabetic patients with periodontal disease, one of the most common dental problems tend to have more tooth loss. consequently, they require diverse and effective restoration and prosthetic modality including fixed, removable and implant treatment. prior to implant placement, implant site drilling procedure is performed and both bone necrosis and remodeling process are required stable blot clot formation between the placed implant and adjacent bone is essential for new osteogenic cell population.19 hyperglycemic state in diabetic patients may reduce clot quality due to poor, ineffective cell adhesion and abnormal collagen remodeling. so, biomechanical retention must be considered more carefully for the implant restoration of these patients. the objective of this cross - sectional study was to analyze effect of type 2 diabetes on tooth mortality, implant treatment and prosthetic status among patients with and without diabetes mellitus. the subject samples were recruited from patients referred to the department of periodontology, kyungpook national university dental hospital for treatment of chronic periodontitis between june 2009 and december 2012. subjects with missing data for dental examinations, smoking, age, and gender were excluded. finally, 275 subjects with type 2 diabetes mellitus and 300 non - diabetic (control) aged 40 - 80 years were available for analyses. patients had received periodontal treatment (with surgical treatment if required) and have been on a recall schedule for supportive periodontal therapy since completing active treatment. frequency of recalls was determined by the patient 's periodontal health and oral hygiene status. diabetes was diagnosed when the level of fasting plasma glucose is more than 126 mg / dl or the level of two - hour postprandial glucose is more than 200 mg / dl. (american dental association : diabetes care 26 (supppl 1) : 5, 2003) diabetic patients were referred from department of endocrinology, kyungpook national university dental hospital. the study protocol was reviewed and accepted by the research ethics committee, kyungpook national university (ethics reference no. knuh2012 - 06 - 023 - 001). clinical examinations were conducted, including the assessment of number of teeth (third molars were excluded from the analysis), missing teeth, fixed (bridge pontics) prostheses, implants using panoramic radiographs and dental records. at the patient 's first visit, extracted teeth and placed implants were also surveyed during treatment period. confounding factors such as cigarette smoking, age, gender were assessed. continuous data were expressed as mean and standard deviation and comparisons between groups were performed using the independent t - test. nominal data were presented as absolute numbers and percent values and comparisons between groups were performed using the chi - square test. for logistic regression model analysis about the number of lost teeth, the patients with 5 or more teeth loss were designated as having higher teeth loss rate. the mean age of patients was 60.3 9.36 years (41 - 80 years). at the first dental examination, the number of lost teeth in all patients and per patient was 1292 and 4.70 5.29, respectively. the number of placed implants in all patients and per patient was 129 and 0.46 1.45, respectively. the number of fixed partial dentures in all patients and per patient was 233 and 0.84 1.03, respectively. during active treatment period, the number of extracted teeth in all patients and per patient was 163 and 0.59 1.40, repectively. the mean age of patients was 56.4 9.70 years (40 - 80 years). at the first dental examination, the number of lost teeth in all patients and per patient was 841 and 2.80 3.62, respectively. the number of placed implants in all patients and per patient was 82 and 0.27 1.04, respectively. the number of fixed partial dentures in all patients and per patient was 249 and 0.83 1.10, respectively. during active treatment period, the number of extracted teeth in all patients and per patient was 149 and 0.49 1.45, respectively. dm patients and control patients did not show a significant difference in the number of placed implants, fixed partial dentures at the first dental exam and the number of lost teeth during active treatment period. however, these two groups showed a significant difference in age, male gender, smoker ratio and number of lost teeth at the first dental exam. dm patients had a higher number of missing teeth (p<.05), age (p<.05), male gender percentage (p=.042), smoker percentage (p<.05) than control patients. in box plot analysis, dm patients also showed probability of high tooth loss than non - diabetics (fig. dm patients showed significantly higher number of tooth loss rate at the first dental exam than non - dmc patients (table 2). in addition, the patients in older group showed significantly higher number of tooth loss rate at the first dental examination than the patients in younger group. in contrast to previously demonstrated reports, the tooth loss rate of smokers did not show the higher value than that of non - smokers, but the difference was not statistically significant. also, male group showed slightly lower tooth loss rate than female group, but did not show a significant result. when multiple variables including diabetes mellitus, age, smoking, gender were considered together, odds ratios about diabetes mellitus and age were slightly decreased and odds ratios about smoking and gender were diabetics and older group patients showed significantly higher tooth loss rate at the first dental exam than non - diabetics and younger group patients, respectively. smokers and gender group did not show a significant difference than non - smokers and female group, respectively. the high level of glucose in the gingival crevicular fluid and blood stream of diabetics could change the environment of the bacterial flora, inducing qualitative changes in microbial community. also, such chronic hyperglycemia may impair the integrity of the tissues of the periodontium. an animal study reported that bone loss pattern in diabetic mice presented rougher and more irregular at crestal area and slightly greater than non - diabetic mice. they suggested that diabetes mellitus may affect independently on periodontal tissue destruction and tooth loss irrespective of the presence or absence of periodontal disease.20 as a result of the chronic hyperglycemia, the formation of ages (accumulated glycation end - products), which is a specific characteristic of diabetes, induces marked changes in cells and extracellular matrix components and makes the periodontium of diabetics vulnerable to the periodontal inflammation.21 the present study supports previous several studies reporting a significant association between diabetes mellitus and tooth loss, implant treatment. tooth loss was evaluated as an indicator and consequence of destructive periodontal disease in several studies. when the number of lost teeth due to periodontal disease was evaluated at the first dental exam, dm patients were more likely to have periodontal disease defined by tooth loss due to periodontitis. tooth loss due to periodontal disease could be identified by asking patients about the cause of tooth extraction such as tooth mobility or gingival problem. the comparison of dm and control subjects at first dental examination allows us to observe that the level of periodontal disease and tooth loss were significantly higher in the dm group and also indicates that prevalence of periodontitis is higher in diabetic patients than in non - diabetics. in fact, those periodontitis patients with dm visited our periodontal clinic first with multiple tooth loss, which means there was insufficient awareness of diabetic mellitus as well as periodontal disease that may have resulted in severe periodontal destruction. it is re - emphasized that periodontal disease is a major universal health problem affecting the majority of the adult population after the age of 35 - 40 years22 and as periodontal disease is designated as the sixth complications of diabetes,23 prevalence and severity of periodontitis typically were increased in diabetic patients. age is a important confounding factor on the risk of periodontal disease,24 and the prevalence of periodontal disease increases with age. studies of risk factors for periodontal disease point out age, smoker as patient - related factors.25 as people ages, the ability of host defense mechanism may decrease with increase in the influence of accumulated periodontal destruction resulting in gradual tooth loss. another epidemiologic study also suggested that specific bacteria played an important role in older adults with periodontal disease.26 in both univariate and multivariate logistic regression analysis of this study, old age groups showed significantly higher odds ratios and higher tooth loss rate. the comparison between smokers and non - smokers did not show such result as expected. as all subjects were classified into only smokers and non - smokers, a certain number of former smokers could belong to non - smoker group. adjusted odds ratios about smokers was nearby one, cautiously suggesting that odds ratios could increase more after the effect of former smokers was offset in non - smokers group. in this study, thorstensson and hugoson27 analysed periodontal disease experience in 40- to 70-year old, sex - matched 83 insulin - dependent diabetics and 99 non - diabetics. they reported that the age of onset appears to be an important risk factor for future periodontal destruction. but, soskolne concluded that for both insulin - dependent diabetes mellitus and non - insulindependent diabetes mellitus, there did not appear to be any correlation between the prevalence of the severity of periodontal disease and the duration of diabetes.28 as age and duration of diabetes may interact in periodontal disease, appropriate study model for evaluating the influence of the duration of diabetes are required. although the number of lost teeth during active periodontal treatement was slightly higher in diabetics than in non - diabetcs, the difference was not statistically significant. as most patients visit periodontal clinic to save or treat their teeth with moderate - severe periodontal destruction, the extraction of hopeless tooth during initial therapy was not ordinary and two groups did not show a significant difference. though the evaluation of tooth extraction during supportive periodontal therapy was required, supportive periodontal therapy period was not sufficient enough to evaluate tooth loss rate. the relationship between periodontal health and diabetes has been described as interactive29 ; periodontitis have an adverse effect on glycemic control and diabetes also have an adverse effect on periodontal health30,31 and studies demonstrates that periodontal treatment in diabetics could improve metabolic state.32 - 34 colonized gram - negative anaerobic microorganisms in severe periodontal lesions may disturb glycemic control in blood stream35 and these conditions trigger diabetic complications. grossi. in their continuous studies reported that the elimination of periodontal infection improved the concentration of glycosylated hemoglobin (hba1c) levels in response to periodontal therapy.36,37 extension of our study to evaluate if active periodontal treatment and subsequent supportive periodontal therapy can improve glycemic state to some degree will also be a stimulating result. it is the long - term metabolic control of the diabetes. in our study, control status of the diabetic condition was not assessed although most patients have received periodontal treatment in our clinic under controlled glycemic state. as it is commonly believed that diabetic patients with poorly - controlled state have a higher prevalence and more aggressive periodontitis than well - controlled diabetics, this is one more important point. in our study, as diabetics showed the higher tooth loss rate than non - diabetics, diabetics also had more implant restorations than non - diabetics. proinfla - mmatory cytokines are essential to lead to bone loss and critical concentration of these cytokines such as il-1,-6,-11,-17, tnf spreads inflammation in the region adjacent bone.38 a mechanism of ages in hyperglycemic condition of diabetics is change in level of cytokines, free radicals, hormones.21 so, impaired osseointegration of implants and high risk of peri - implantitis in patients with diabetes mellitus were reported.39,40 but, invasive dental therapy including implant treatment is not contraindication in well - controlled diabetic patients and several articles reported that the clinical outcome of implants in such diabetics is favorable.41 - 43 in the present study, all patients were restored with implant - supported fixed prostheses and did not develop specific complications. although only one patient of control group lost all maxillary teeth, multiple implant - supported fixed therapy was performed instead of removable denture. generally, a consideration of proper angulation, position and bone quality is appreciated for implant - supported fixed restorations. michaeli. stated bone type and quality, surgical protocol, duration of osseointegration, restoration type as rehabilitative factors in diabetics.44 they mentioned that a removable restoration may be preferred in diabetic patients in cases of difficulty of exact implant localization in the jaw bone. as diabetic patients are recognizing implant treatment as an accepted treatment choice, it is essential to identify whether implants or fixed or removable type can be used in diabetic patients, educate patient to understand their oral and systemic state before treatment and help maintain favorable state after treatment. the tooth mortality implying periodontal disease and implant treatment rate were significantly higher in the dm group and in both univariate and multivariate logistic regression analyses, old age groups showed significantly higher odds ratios and higher tooth loss rate. as implant supported restoration is an alternative therapy, it is necessary to make periodontal patients with dm aware their oral and systemic state before implant treatment and to help them maintain favorable state after treatment. | purposethe purpose of this study was to to analyze the effect of type 2 diabetes on tooth mortality, implant treatment and prosthetic status.materials and methods275 type 2 diabetics and 300 non - diabetics, aged 40 - 80 years were selected for analysis. the assessment of number of teeth, missing teeth, fixed prostheses (bridge pontics), implants using panoramic radiographs and dental records were carried out.resultsdiabetes mellitus (dm) patients had a higher number of missing teeth (p<.05) and placed implants (p=.074), age (p<.05), male gender percentage (p=.042), smoker percentage (p<.05) than non - dm patients. in univariate analysis, the patients in older group showed significantly higher number of tooth loss rate at the first dental examination than the patients in younger group. tooth loss rate of smokers did not show higher value than that of non - smokers. when multiple variables including dm, age, smoking, gender were considered together, diabetics and older group patients showed significantly higher tooth loss rate at the first dental examination than non - diabetics and younger group patients, respectively. smokers and male group did not show a significant difference than non - smokers and female group, respectively.conclusiontooth mortality and implant treatment rate were significantly higher in the dm group as indicated by univariate and multivariate logistic regression analysis. old age groups showed significantly higher odds ratios and tooth loss rate. as diabetics showed the higher tooth loss rate than non - diabetics, diabetics also had more implant restorations than non - diabetics. |
the goal of treatment of cerebral aneurysm is completely obliteration of their lumen, excluding the entire aneurysm from the arterial circulation. usually microsurgical clipping attains this goal, but aneurysm remnants can occur in 5.2% of patients who undergo postoperative angiography16). these remnants are associated with potential for subarachnoid hemorrhage from rupture and regrowth over time6, 7). in second operation, surgeons often experience technical difficulty because of scars or dense adhesions surrounding the aneurysm, and configuration and location of aneurysm5). there have been technical improvements in endovascular coiling, and technology has allowed some of these remnants to be treated safely1,15). however, endovascular coil embolization also has limitations in the treatment of wide - neck aneurysm due to possible coil migration into the parent artery and long - term recurrence4,18). technical advances make it possible to treat wide - neck aneurysm using variety of endovascular strategies such as double catheter technique10), balloon - assisted coiling13), and stent assisted coiling2,14). recently, the stent - jack3) and semi - jailing9,19) techniques have been introduced for patients with broad - necked aneurysm. we report a case of remnant wide - neck aneurysm with small caliber parent artery (about 1 mm) following clipping, treated by a temporary semi - jailing technique12) using the enterprise stent system (cordis neurovascular, miami, fl, usa). a 41 years old man with seizure like movement was admitted to our hospital. he had a history of hypertension treatment for 3 years. on neurologic examination, the patient was drowsy (glasgow coma score : e3, v4, m6). he showed 2/5 and 3/5 strength in the right and left lower extremity and 5/5 strength in both upper extremities. initial computed tomography (ct) revealed the presence of a subarachnoid hemorrhage and aneurysm in the a1 segment of the anterior cerebral artery (aca) with inferior and superior projection. but superior and posterior portion of the aneurysm remained on follow - up transfemoral cerebral angiography (fig. the patient was placed on 300 mg of clopidogrel, 100 mg of aspirin one day before embolization and 75 mg of clopidogrel, 100 mg of aspirin on the day of operation. a prowler select plus microcatheter (cordis neurovascular, miami, fl, usa) was navigated across the aneurysm neck over a 0.014 '' microguidewire. an excelsior sl-10 microcatheter (striker, fremont, ca, usa), for coil delivery were carefully navigated to the aneurysm. through prowler select plus microcatheter, the stent was partially deployed (up to 30 - 60% of its length) bridging the aneurysm 's wide neck. subsequent coil packing (4 coils, sizes ranging from 230 mm to 1.510 mm, micrus endovascular) resulted in subtotal occlusion of the aneurysm without coil herniation through the stent struts into the parent lumen (fig. whenever each coil was inserted, the stent was partially recaptured into the prowler select plus microcatheter then the sl-10 microcatheter was removed for angiography to ensure safety of the small caliber parent artery (fig. a final control angiogram confirmed aneurysm occlusion, and preservation of the blood flow within the territory including a1 segment (fig. follow - up transcranial doppler ultrasonogram showed patent blood flows of bilateral acas (right : left, mean=78 : 74, systolic 118 : 104, diastolic=54 : 55). further clinical and neurological follow - up examinations are planned after 1 and 3 months, and digital subtraction angiogram (dsa) follow - up are planned after 6 months. the aneurysm remnants after surgical clipping may be caused by anatomic complexities, technical difficulties at the time of surgery and regrowth after surgery5,8,11). in this case, the superior and posterior compartment of aneurismal sac can not be clipped because of limitation imposed by the configuration and location of the aneurysm. second surgeries usually face scars or dense adhesions surrounding the aneurysm in proportion to the interval between surgeries5). with evolution of devices and techniques of endovascular treatment, in addition, endovascular and surgical modalities can be successfully incorporated into a single therapeutic plan and can result in good outcome7,17). from a technical point of view, remnant coiling is usually possible if the remnant is at least as deep as it is wide and if it is at least 2 mm in diameter1). however, there are several challenging factors in the endovascular treatments of wide - neck aneurysm with small caliber parent artery. second, supporting devices such as balloon and stent have several limitations. using the balloon remodeling technique in small caliber parent artery can cause periodic flow arrest to the parent vessel, which may result in thromboembolic or rupture complications. permanent stent deployment in small caliber parent artery also has a risk of in - stent stenosis or occlusion as the long - term outcome. the recommended parent vessel diameter for permanent deployment of enterprise stent is 2.5 - 4 mm. stent - assisted coiling of wide - neck aneurysms is not recommended in patients with gastrointestinal bleeding, complex medical problems, or those scheduled for subsequent surgery, and in patients with acute subarachnoid hemorrhage because antiplatelet medication is required. the technique depicted in this case report was very helpful in successfully coiling a wide - neck aneurysm with small caliber parent artery. it was very critical to lock the stent delivery wire with a hemostatic valve once the stent was partially deployed, to prevent further deployment of the stent12). repeated recapture and coil microcatheter removal are necessary to ensure the patency of a small caliber parent artery on dsa. before recapture of the stent, it is important to wait for several minutes to make sure of coil mass stability, and ascertain coil mass stability under digital subtraction background during retrieval. if coil movement is detected during stent retrieval, redeployment of the stent would be the rescue maneuver. temporary stenting for wide neck aneurysm is a feasible technique for wide - neck aneurysm with small caliber parent artery. | the authors describe the use of a self - expandable stent in a temporary deployment for treatment of a very wide - neck a1 segment of anterior cerebral artery (aca) aneurysm following incomplete clipping. a 39-year - old hypertensive man presenting with seizure - like movement underwent computed tomography, which showed acute subarachnoid hemorrhage and an a1 segment of aca aneurysm with superior and inferior projection. he underwent surgical clipping of the aneurysm, but superior and posterior portion of wide - neck aneurysm remained. we decided to treat the remnant aneurysm using an endovascular modality. after selection of the aneurysm, coil packing was performed assisted by the temporary semi - jailing technique. the enterprise stent (cordis neurovascular, miami, fl, usa) was deployed and recaptured repeatedly for angiography to ensure safety of the small caliber parent artery. successful semi - deployment and recapture of the stent allowed subtotal coil occlusion of the aneurysm with good anatomic and clinical results. no complications were encountered. the stent could be recaptured up to the point where the proximal end of the stent marker was aligned with distal marker band of the microcatheter, approximately 70% of the stent length. the temporary semi - jailing technique is feasible for wide - neck aneurysm with small caliber parent artery. |
infection with hepatitis c virus (hcv) had a prevalence of nearly 0.14% in 2005 and 0.12% in 2007 among the blood donors in iran. rather than hepatitis b infection which is the most common cause of viral chronic liver dysfunction at the present, it might thus be the most common cause of chronic viral liver disease in the near future. hence, identifying the prognostic and associating factors, which predict the condition of the disease and its response to the treatment, can play an important role in determining the therapeutic strategies. the progression of liver fibrosis in patients with hcv infection is a dynamic process that varies considerably in different patients. the rate of progression is affected by the interaction between genetic factors of the host and pathogen, and environmental factors. alcohol consumption, smoking, and environmental pollutants are known environmental (external) factors, which affect the progression of the disease. host - related factors are gender, duration of infection, race, human leukocyte antigen (hla) types, genetic polymorphisms (e.g. patatin - like phospholipase-3), and concurrent infections [e.g. hepatitis b virus (hbv) and human immunodeficiency virus (hiv) ]. new evidence has suggested a role for the clotting process, which can provoke liver fibrosis in patients with hcv infection. a number of studies reported several risk factors for venous thrombosis in patients with extensive liver fibrosis, and early cirrhosis due to hcv infection. furthermore, the risk of thrombosis in patients with non - alcoholic fatty liver disease was associated with advanced liver fibrosis and nonalcoholic steatohepatitis. in addition, several other studies have shown that the mutation in factor v leiden (fvl), the most common genetic risk factor for venous thrombosis, may be an independent risk factor for progression of liver fibrosis in hcv infection, as well. moreover, c protein deficiency, increased factor viii expression, and hyperhomocysteinemia, as other risk factors for thrombosis, are associated with the rapid progression of cirrhosis in chronic hepatitis c infection. a cohort study showed that liver fibrosis in hcv infection progressed slowly in hemophilic patients. in fact, only 3% of these patients, who were heavy alcohol users, died due to liver dysfunction. it seems that hypercoagulant and thrombotic states can reveal fibrogenesis in liver. in addition, anti - thrombotic state is associated with slower progression of liver fibrosis. another genetic factor, which almost doubles the risk of venous thrombosis, is the non - o blood group.[1315 ] recent studies have shown that in patients with a known risk of venous thrombosis, such as mutation in fvl, the presence of non - o blood group may significantly increase the risk of venous thrombosis. despite several evidence suggesting the genetic factor of non - o blood group as a risk factor for venous thrombosis, there is only one study suggesting the role of non - o blood group for liver fibrosis in patients with hcv infection with the relative risk of 1.8. regarding the interaction between the genetic and environmental factors in liver fibrosis in hcv, and the importance of understanding the factors increasing the risk of liver fibrosis, we aimed to determine the association of non - o blood group with liver fibrosis in iranian patients with hcv infection. this cross - sectional study was conducted from 2009 to 2010 on iranian patients with hcv infection. the study was held in the gastroenterology clinics of isfahan university of medical sciences (isfahan, iran). inclusion criteria were an age of 18 years or over, proven hcv infection based on viral load and hcv antibody (ab), negative hepatitis b surface antigen (hbs ag), negative hiv ab, no other liver diseases confirmed by necessary laboratory tests such as ceruloplasmin, 24-hour urine copper, and liver autoantibodies, and no previous hcv antiviral therapy. with an alpha of 0.05 and power of 80% the study was approved by the ethics committee of isfahan university of medical sciences and written informed consents were obtained from all participants. demographic information, including age and gender, and abo blood group of the patients were collected through interviews and reviewing patient records at the time of liver biopsy. to determine the severity of hepatic fibrosis, liver biopsies were taken with a bard needle. the samples were fixed in bouin 's fluid, embedded in paraffin, and then divided into small pieces and stained with hematoxylin and eosin. histological fibrosis was measured by a pathologist who was blinded to the study and patients ' information. based on metavir system, histological fibrosis was classified as f0 (without cirrhosis), f1 (portal fibrosis without septa), f2 (portal fibrosis with rare septa), f3 (numerous septa without cirrhosis), or f4 (cirrhosis). data was analyzed in spss16.0 (spss inc., chicago, il, us) using univariate and multivariate tests. this cross - sectional study was conducted from 2009 to 2010 on iranian patients with hcv infection. the study was held in the gastroenterology clinics of isfahan university of medical sciences (isfahan, iran). inclusion criteria were an age of 18 years or over, proven hcv infection based on viral load and hcv antibody (ab), negative hepatitis b surface antigen (hbs ag), negative hiv ab, no other liver diseases confirmed by necessary laboratory tests such as ceruloplasmin, 24-hour urine copper, and liver autoantibodies, and no previous hcv antiviral therapy. with an alpha of 0.05 and power of 80% the study was approved by the ethics committee of isfahan university of medical sciences and written informed consents were obtained from all participants. demographic information, including age and gender, and abo blood group of the patients were collected through interviews and reviewing patient records at the time of liver biopsy. to determine the severity of hepatic fibrosis, liver biopsies were taken with a bard needle. the samples were fixed in bouin 's fluid, embedded in paraffin, and then divided into small pieces and stained with hematoxylin and eosin. histological fibrosis was measured by a pathologist who was blinded to the study and patients ' information. based on metavir system, histological fibrosis was classified as f0 (without cirrhosis), f1 (portal fibrosis without septa), f2 (portal fibrosis with rare septa), f3 (numerous septa without cirrhosis), or f4 (cirrhosis). data was analyzed in spss16.0 (spss inc., chicago, il, us) using univariate and multivariate tests. this cross - sectional study was conducted from 2009 to 2010 on iranian patients with hcv infection. the study was held in the gastroenterology clinics of isfahan university of medical sciences (isfahan, iran). inclusion criteria were an age of 18 years or over, proven hcv infection based on viral load and hcv antibody (ab), negative hepatitis b surface antigen (hbs ag), negative hiv ab, no other liver diseases confirmed by necessary laboratory tests such as ceruloplasmin, 24-hour urine copper, and liver autoantibodies, and no previous hcv antiviral therapy. with an alpha of 0.05 and power of 80% the study was approved by the ethics committee of isfahan university of medical sciences and written informed consents were obtained from all participants. demographic information, including age and gender, and abo blood group of the patients were collected through interviews and reviewing patient records at the time of liver biopsy. to determine the severity of hepatic fibrosis, liver biopsies were taken with a bard needle. the samples were fixed in bouin 's fluid, embedded in paraffin, and then divided into small pieces and stained with hematoxylin and eosin. histological fibrosis was measured by a pathologist who was blinded to the study and patients ' information. based on metavir system, histological fibrosis was classified as f0 (without cirrhosis), f1 (portal fibrosis without septa), f2 (portal fibrosis with rare septa), f3 (numerous septa without cirrhosis), or f4 (cirrhosis). in our study, 200 hcv infected patients (mean age = 38.7 10.0 years, 77.4% male) were included. among these, 50 patients (25%) had o blood group and 150 (75%) had non - o blood groups. the distribution of liver fibrosis was f0 : 26 patients (13.0%) ; f1 : 65 (32.5%) ; f2 : 56 (28%) ; f3 : 32 (16%), and f4 : 21 (10.5%). the severity of liver fibrosis according to the patients ' profile is shown in the table 1. non - o blood group was associated with more severe liver fibrosis (p = 0.019). however, there was no significant relationship between the severity of hepatic fibrosis and patients age or gender (p > 0.05). severity of liver fibrosis according to patients characteristics and blood type considering the possibility of multiple factors affecting the severity of liver fibrosis, ordinal regression analysis was used to determine the association of each factor independently (table 2). among these factors, only the viral load (p = 0.028) and non - o blood groups (p = 0.001) were associated with the severity of hepatic fibrosis. the aim of the present study was to evaluate the relationship between non - o blood group and the severity of liver fibrosis in iranian patients with hcv infection. the study showed that non - o blood group had a direct and independent correlation with the severity of hepatic fibrosis. in france who reported male gender, duration of hcv infection, the amount of alcohol consumption, and non - o blood group to be independent factors associated with the severity of liver fibrosis in hcv infected patients. however, there was not any association between the severity of liver fibrosis and gender in our study. moreover, the two factors of duration of hcv infection and the amount of alcohol consumption were not evaluated in our study since history taking is not reliable enough to calculate the infection duration based on the date of the first intravenous injection or first blood infusion. on the other hand, due to our cultural and legal characteristics, patients would not provide true information about their alcohol use. despite these differences however, like our findings, poujol - robert. suggested non - o blood group as a predictor of liver fibrosis with a relative risk of 1.8, independent of other factors including the duration of hcv infection and the value of alcohol consumption. the association between the progression of liver fibrosis and non - o blood group can be justified considering that the blood type itself is an independent risk factor for venous thrombosis which has an important role in the progression of liver fibrosis. in addition, the mutation of fvl, which is the most common genetic risk factor for venous thrombosis, is significantly associated with the progression of liver fibrosis in hcv patients. likewise, in animal models, liver fibrosis treated with anticoagulants like warfarin has reduced the rate of fibrosis. two general mechanisms have been proposed for the activation of coagulation pathways in the progression of liver fibrosis. the first is that the thrombosis in the microscopic vessels of the liver can cause fibrosis due to tissue ischemia. another possible mechanism is the activation of stellate cell by thrombin, which initiates the process of liver fibrogenesis. thrombotic effects of non - o blood group can be due to its effect on plasma levels of factor viii. therefore, non - o blood group has an evidently higher level of this factor comparing to the o blood group. on the other hand, higher risk of venous thrombosis the mechanisms through which factor viii levels and increased risk of thrombosis are significantly influenced by abo blood group have not been well identified. despite the evidence indicating the role of thrombosis in the progression of liver fibrosis, there have been a few clinical studies on the effectiveness of anticoagulation therapy as an anti - fibrotic treatment. moreover, the evidence does not recommend the routine use of this type of treatments. further clinical investigations are thus needed to determine the safety and efficacy of such medications. according to this study, non - o blood group is an independent genetic risk factor for the progression of liver fibrosis in patients with hcv infection. it plays an important role in determining the prognosis and therapeutic strategies of the disease. the relationship between non - o blood group and liver fibrosis is probably due to increased risk of venous thrombosis, which can be a target to prevent the progression of liver fibrosis in non - o blood group patients with hcv infection in future studies. | background : the progression rate of liver fibrosis is variable among patients with hepatitis c virus (hcv) infection. it is affected by environmental and genetic factors. we determined the association between abo blood groups and the severity of liver fibrosis in hcv patients.materials and methods : this cross - sectional study was conducted on adult patients with chronic hcv infection who referred to university clinics in isfahan, iran in 2009 - 10. patients with positive hepatitis b surface antigen (hbs ag), human immunodeficiency virus antibody (hiv ab), or other liver disorders, as well as those who had received anti - hcv treatments were not included. blood type was determined and liver biopsy was obtained from all patients. the severity of hepatic fibrosis was graded from f0 to f4 based on metavir system.results:non-o blood groups were present in 53.8%, 72.3%, 75%, 87.5%, and 90.4% of the patients with f0-f4 grades of liver fibrosis, respectively (p = 0.019). there was no relationship between the severity of hepatic fibrosis and age or gender. in ordinal regression analysis, only the viral load (p = 0.028) and non - o blood group (p = 0.001) were associated with the severity of hepatic fibrosis.conclusion:non-o blood group is a genetic risk factor for progression of liver fibrosis in patients with hcv infection. it can play an important role in determining the prognosis and appropriate treatment among these patients. the association between blood group and liver fibrosis is probably due to the increased risk of venous thrombosis. such relation can be the goal of preventive / treatment strategies. |
research reviews have established the rapid, albeit short - lived antidepressant effect of subanesthetic dose of ketamine, a noncompetitive glutamate n - methyl - d - aspartate receptor antagonist, in major depressive disorder (mdd), bipolar depression, depression with suicidal ideation and treatment - resistant depression (trd). ketamine is known to cause transient mood elevation or euphoria, psychotomimetic effects, and dissociative symptoms, but its use in unipolar or bipolar depression has not been reported to induce an affective switch amounting to persistent or prolonged mania or manic - like syndrome. while searching for literature, we could find only one account of a female patient receiving ketamine therapy for reflex sympathetic dystrophy (with comorbid depression) who subsequently developed prolonged mania and associated psychotic symptoms. we report the case of a male patient with trd, who manifested a switch from depression to mania while being treated with a subanesthetic dose of ketamine. a 52-year - old male presented with first episode, continuous, nonpsychotic, unipolar mdd of 10 years duration. laboratory investigations (including serum vitamin b12 and d3 levels) were within the normal reference range. past treatment records revealed that he had received adequate treatment trials (in terms of doses, duration, and compliance) of fluoxetine, escitalopram, sertraline, imipramine, bupropion, moclobemide, lithium, lamotrigine, methylphenidate, fluoxetine - olanzapine combination, quetiapine, and aripiprazole, as mono - or combination therapy. in the 10 years of being on treatment, sleep, appetite, and concentration improved on medication in varying degrees, but depressed mood and diminished interest in most activities almost always persisted without much change. throughout the duration of illness, he had experienced a feeling of passive death wish but never had suicidal ideation or attempts. at the time of presentation to us, he scored 26 on the 17-item hamilton rating scale for depression (hrsd). we prescribed a combination of venlafaxine and mirtazapine, in doses of 300 mg and 30 mg respectively, up - titrated over a period of 3 weeks. at the end of 12 weeks, he scored 20 on hrsd. electroconvulsive therapy was considered, but the patient and his family members denied consent. feeling that the medications were not helping him much, he went off treatment for 22 days but did not report much worsening of symptoms, apart from mild headaches and impaired sleep. we then administered ketamine intramuscularly in a dose of 0.3 mg / kg, as the patient consented for the same. he scored 16 on hrsd and 17 on young mania rating scale (ymrs). two more injections of ketamine were given in the same dose at an interval of 2 days each time. his scores before the second and third injections were 18 on hrsd, 13 on ymrs and 16 on hrsd, 14 on ymrs, respectively. after 2 h of the second and third injections, his scores were 12 on hrsd, 18 on ymrs and 10 on hrsd, 20 on ymrs respectively. family members complained that he was unduly cheerful and energetic, talking more than usual, restless and fidgety, unusually grooming well, singing songs aloud and picking fights in the neighborhood, especially after the third injection. in absence of any such past history or concurrent antidepressant or substance use, it was postulated that the patient had an affective switch from depression to mania induced by ketamine ; the assertion supported by a score of 9 on the naranjo adverse drug reaction probability scale. he was then prescribed lithium 900 mg (in two divided doses), and paroxetine extended - release 25 mg. the international society for bipolar disorders task force has defined a treatment - emergent affective switch as likely with at least two manic symptoms lasting more than 50% of the day for 2 days and a ymrs > 12. our patient clearly fulfilled this definition, and the polarity switch may thus be attributed to ketamine, in the absence of any concomitant antidepressant medication. wada., reported the prevalence of manic / hypomanic switch during acute antidepressant treatment in their sample of admitted unipolar mdd patients to be 13.1%, and the manic / hypomanic episodes lasted from 1 to 8 weeks ; the switch occurring more commonly in males. interestingly, our patient had never developed manic / hypomanic symptoms anytime in the past while receiving antidepressant treatment. in the 6 months following the subsidence of the switch episode, he did not present with manic / hypomanic symptoms again, but he was also taking lithium along with paroxetine. a study examining the long - term outcome of moderate / severe unipolar mdd patients with mood switch during acute antidepressant treatment found that no subject presented spontaneous mania / hypomania (once antidepressant maintenance treatment had finished) during 3 years of follow - up. niciu., analyzed data from their three independent studies (constituting a total of 98 treatment - resistant unipolar or bipolar major depressed patients) for treatment - emergent manic - like symptoms as assessed using ymrs, while being administered subanesthetic dose ketamine. they concluded that there was insufficient evidence to support that ketamine induces a switch of polarity from depression to mania. furthermore, they critically evaluated the case presented by ricke., which claimed induction of prolonged mania in a patient during ketamine therapy for reflex sympathetic dystrophy, with comorbid depression and insomnia, and questioned the authors attribution of the affective switch to ketamine. with the growing evidence and increasing use of ketamine for treatment - resistant unipolar mdd, our case report suggests that clinicians should consider affective switch as its potential side effect. | there is growing evidence to support the rapid, albeit short - lived antidepressant effect of subanesthetic dose of ketamine, a noncompetitive glutamate n - methyl - d - aspartate receptor antagonist in treatment - resistant unipolar and bipolar depression. ketamine is known to cause transient mood elevation or euphoria, psychotomimetic effects, and dissociative symptoms, but its use in unipolar or bipolar depression has not been reported to induce an affective switch amounting to persistent or prolonged hypomania / mania or manic - like syndrome. we report the case of a 52-year - old male with first episode, continuous, nonpsychotic, treatment - resistant, unipolar major depression of 10 years duration, who manifested a switch from depression to mania while being treated with subanesthetic dose of ketamine, given intramuscularly. this case suggests that polarity switch should be considered as a potential side effect while using ketamine for treatment - resistant depression. |
inflammatory fibroid polyp (ifp) is a rare, idiopathic pseudo - tumorous lesion of the gastrointestinal tract, first described by vanek in 1949 as an eosinophilic submucosal granuloma (1).they typically present in the 5 to 7decade of life (2). many have suggested etiologies possibly related to chemical, physical, or metabolic triggers (3). when present, they are mostly found in the gastric antrum (70%) or in the ileum (20%) ; however, they are considered to be very rare in the duodenum and jejunum(2). symptoms depend on the location of the lesion, including abdominal pain, vomiting, altered small bowel movements, gi bleeding and loss of weight. ifps arising below the treitz ligament can present with an acute abdomen (obstructive ileus) usually due to intussusceptions (4, 5). here, we report an unusual case of jejenojejunal intussusception caused by an ifp, the diagnosis of which was confirmed by immunohistochemistry. a forty years old woman was admitted to the emergency unit suffering from progressive abdominal pain, nausea and vomiting for 3 days. for the past three days she had complaints of a dull postprandial cramping abdominal pain. the physical examination of abdomen revealed muscular guarding and rebound tenderness in the peri - umbilical region. air fluid level is observed. abdominal ultrasonography prior to her admission revealed a mass in right lower quadrant with a pseudo - kidney pattern and suggested intussusceptions (figure 2). surgical consult was requested and the patient was planned for urgent laparotomy with a diagnosis of small bowel obstruction. histopathological finding showing ulcerative lesion with variable cellularity. at the surgery a jejunal tumor causing jejuno - jejunal intussusceptions was found (figure 3). post - surgical course was unremarkable and the patient was discharged after 7 days in a good condition. postoperative macroscopic examination of the surgical specimen showed a firm 1851 cm mass, with foci of hemorrhage or grayish exudates and luminal surface that was composed of autolytic mucosa of thin nodularity and egg shaped mass. the lesion involved the entire thickness of the bowel wall with extensive ulceration of the overlying mucosa. histopathological analysis showed an ulcerative lesion with variable cellularity, formed by spindle cells with small number of mitosis and an abundant inflammatory infiltrate comprising mainly with eosinophils (figure 2). among the spindle cells blood vessels with thickened walls and vessel congestions at the sub mucosa and mucosa the primary diagnoses were doubted between gastro - intestinal stromal tumor (gist) and vanek tumor. histological hematoxylin - eosin (he) stain sections revealed an inflammatory lymphoid polyp of the small bowel with active luminal surface ulcer which was covered with fibrino - purulent exudates. six months after the surgery the patient was in no distress ; she had some symptoms of bloating and mild change in her bowel movement. a thorough evaluation including complete laboratory examinations, upper endoscopy, colonoscopy with distal ileal evaluation and small bowel series were normal. they fall under the classification of sub mucosal connective tissue tumors and were first described by vanek (1). they usually are discovered in the 5 to 7decade of life and can be found throughout the gastrointestinal (gi) tract but most commonly in the gastric antrum (70%) or ileum (20%), but rarely in the duodenum and jejunum (2). the underlying cause of inflammatory fibroid polyps (ifps) is still unknown. many have suggested etiologies possibly related to chemical, physical, or metabolic triggers (3). histologically they arise from the sub mucosa and are characterized by vascular and fibroblast proliferation and an inflammatory response, dominated by eosinophils (3). further immuneohistochemical analysis can demonstrate variable reactivity for actin, cd34, desmin, cd117 and s100 (3). most ifps are polypoid masses smaller than 5 cm, but occasional reports of larger sizes up to 20 cm have been reported(68).in most patients, in whom ifps are located in thes mall bowel, the clinical picture is characterized by symptoms and signs of obstructive ileus, usually due to the intussusception, and rapidly becomes a surgical emergency (59). pre - operative diagnosis of intussusceptions is rare but can occur in finding a palpable mass on the abdomen or with the use of imaging techniques (10). the primary imaging modality of choice is ultrasound scanning, which enables the diagnosis or exclusion of intussusceptions with a sensitivity of 98 and 100%, respectively, a specificity of 88%, and a negative predictive value of 100% (11). in some cases abdominal ct scan has also been used as the primary diagnostic tool (8). in the current case report, the patient presented with a dull, postprandial cramping abdominal pain. this case highlighted the importance of performing a thorough examination, even when patients present with unusual symptoms that are suspicious of functional pain. this case report demonstrates that intussusceptions, although rare in adults, should be considered in the differential diagnosis of abdominal pain. in this case, the preoperative clinical findings and ultrasonic images suggested invagination. the ultrasound images of the small bowel lumen showed a mass of 11 cm in diameter. abdominal pain is the most common symptom, followed by vomiting and nausea (12). about 1000 ifps have been described thus far in the literature, of which 70% were gastric in origin. other gi sites affected (in decreasing order of frequency) were small bowel (mainly the ileum) (23%), colon and rectum (4%), gallbladder (1%), esophagus (1%), duodenum (1%), appendix (< 1%) (13). an astonishing feature of the current case was the huge size of the tumor and its silent growth for eventually a couple of years without having any clinical presentation, until three days before the clinical presentation as an incomplete intestinal obstruction. causes of intestinal obstruction in adult patients include adhesion bands, malignant tumors and hernia in descending order of appearance. here we showed that in some cases benign tumors even at large sizes can be a cause for small intestinal obstruction and hence should be included in the pre - operative diagnostic list. in conclusion, the recommended treatment of adult intestinal invagination is surgical resection of the intestinal segments involved ; which was performed in our case and this was curative with no longstanding complication. | inflammatory fibroid polyp (known also as vanek 's tumor) is a type of localized, non - neoplastic inflammatory pseudotumor or inflammatory myofibroblastic tumor that occurs most commonly in the stomach but also in the small and large bowel. it is a documented cause of intussusception in adults. we report a case of a 40-year - old woman who presented with severe, postprandial abdominal pain followed by projectile vomiting over a period of three days. ultrasonography demonstrated a solid and echogenic mass surrounded by the typical mural layers of an invaginated jejunum. she underwent urgent laparotomy and resection of an 18 cm tumor from the distal jejunum. the immuno - histopathological diagnosis after segmental jejunal resection was a jejunal inflammatory fibroid polyp. although inflammatory fibroid polyps are seen very rarely in adults, they are among the probable diagnoses that should be considered in obstructive tumors of the small bowel causing intussusceptions. |
health and medical tourism, one of the fastest growing segments in marketing, is becoming a worldwide, multibillion - dollar industry today (1). till date, this area has so far been relatively unexplored in india. but now, not only the ministry of tourism, government of india, but also the various state tourism boards and even the private sector consisting of travel agents, tour operators, hotel companies and other accommodation providers are all eying health and medical tourism as a segment with tremendous potential for future growth (24) what s exactly medical tourism ? medical tourism, medical travel, health tourism or global healthcare is a term initially coined by travel agencies and the mass media to describe the rapidly - growing practice of travelling across international borders to obtain health care. in simple terms, it is people going to different countries for medical care that encompasses either urgent or elective medical procedures (5, 6). the reasons that encompasses the need for medical tourism vary - many medical tourists from the united states are seeking treatment at a quarter or sometimes even a 10 of the cost in other countries (7). from canada, it is often people who are frustrated by long waiting times (8). from great britain, the patients who ca nt wait for treatment by the national health service or ca nt afford to see a physician in private practice opt for it. for others, becoming a medical tourist more patients are coming from poorer countries such as bangladesh where treatment may not be available (9, 10). countries so promoting medical tourism include cuba, costa rica, hungary, india, israel, jordan, lithuania, malaysia and thailand. popular medical travel destinations include : argentina, brunei, cuba, colombia, costa rica, hong kong, hungary, india, jordan, lithuania, malaysia, the philippines, singapore, south africa, thailand, and recently, saudi arabia, uae, tunisia and new zealand. and popular cosmetic surgery travel destinations include : argentina, bolivia, brazil, colombia, costa rica, cuba, mexico and turkey. south africa specializes in medical safaris - people visit the country for a safari, with a stopover for plastic surgery, a nose job and a chance to see lions and elephants (11, 12). but how is it relevant to india ? in india, medical tourism is on the rise. according to the study conducted by the confederation of indian industry and mckinsey consultants, last year some 150,000 foreigners visited india for treatment, with the number rising by 15 per cent a year. with an increasing number of foreign patients flocking to india for treatment, the country could earn rs 100 billion (us$2.3 billion) through medical tourism by 2012, (13). more people from the united states, europe and the middle east are seeking indian hospitals as a cheap and safe alternative (14). with more people heading to india for medical tourism, the question arises, are the medical standards good enough ? absolutely yes, the indian medical standards match up to the highly prescribed international standards. the lower costs are due to favorable currency conversion rates and lower costs of operating in india (15, 16). an elective procedure such as a knee replacement would cost 4060% less than the cost in the us or uk, including the hospital stay, all procedure and physicians costs and transportation to and from india. it is estimated that foreigners account for about 12 per cent of all patients in top hospitals of mumbai, like lilavati, jaslok, breach candy, bombay hospital, hinduja hospital, apollo and wockhardt (17, 18). the field has such lucrative potential that india became a stage for global health destination. and, with prices at a fraction of those in the us or britain, the concept will likely have broad consumer appeal - if people can overcome their prejudices about health care in developing countries (19). though the quality of health care for the poor in countries like india is undeniably low, private facilities offer advanced technology and procedures on par with hospitals in developed nations (20, 21). but there are certain parallel issues around medical tourism too, like international healthcare accreditation, evidence - based medicine and quality assurance. over 50 countries have identified medical tourism as a national industry. however, accreditation and other measures of quality vary widely across the globe (22). in the united states, joint commission international (jci) fulfills an accreditation role, while in the uk and hong kong, the trent international accreditation scheme is a key player. the different international healthcare accreditation schemes vary in quality, size, cost, intent and the skill and intensity of their marketing. they also vary in terms of cost to hospitals and healthcare institutions making use of them (23). a forecast by deloitte consulting regarding medical tourism published in august 2008 noted the value of accreditation in ensuring quality of healthcare and specifically mentioned jci, isqua and trent. differences in healthcare provider standards around the world have been recognised by the world health organization, and in 2004 it launched the world alliance for patient safety (24). this body assists hospitals and government around the world in setting patient safety policy and practices that can become particularly relevant when providing medical tourism services. certain risks and ethical issues too make this method of accessing medical care controversial. and, some destinations may become hazardous or even dangerous for medical tourists to contemplate. some countries, such as india, malaysia, costa rica, or thailand have very different infectious disease - related epidemiology in contrast to europe and north america. exposure to diseases without having built up natural immunity can be a hazard for weakened individuals, specifically with respect to gastrointestinal diseases (e.g. hepatitis a, amoebic dysentery, paratyphoid) which could weaken progress, mosquito - transmitted diseases, influenza, and tuberculosis. however, because in poor tropical nations, diseases run the gamut, doctors seem to be more open to the possibility of considering any infectious disease, including hiv, tb, and typhoid, while there are cases in the west where patients were consistently misdiagnosed for years because such diseases are perceived to be rare in the west (25). transplant tourism is a new and shady concern on the global level and especially for india, as it is also known as warehouse for organ transplantation or a great organ bazaar owing to easy availability of organs at low cost in india, majority of population is living below poverty line and financial constraints make many people as vulnerable candidates for organ donation. in developing countries, a kidney transplant operation runs for around $ 70,000, liver for $ 160,000, and heart for $ 120,000. although these prices are still unattainable to the poor, compared to the fees of the united states, where a kidney transplant may demand $ 100,000, a liver $ 250,000, and a heart $ 860,000 (26). not only this, the commercial transplantation has also resulted in increase in non adherence to organ transplantation act. and this in turn has posed a great threat for the organ recipients owing to inadequate screening and testing of various infectious diseases like hiv, hepatitis, malaria and tuberculosis. hence, a regulated system with radical reforms is needed that would provide strict control and limit harm by allowing every candidate an opportunity for transplant, full donor evaluation, informed consent, long term follow up, with payment managed by the government or insurance companies and the banning of any other commercialization. but inspite of all this in india healthcare tourism is gaining leverage and becoming as a high demand industry. also an overall blend of top - class medical expertise at attractive prices is helping a growing number of indian corporate hospitals to lure foreign patients, including from developed nations such as the uk and the us. and now india is moving into a new arena of medical outsourcing, (27) where subcontractors provide services to the overburdened medical care systems in western countries. undoubtedly, indian doctors are setting up what could be a medical renaissance in their country and the next great boom for the indian economy. ethical issues (including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, redundancy, etc) have been completely observed by the authors. | globalisation has given birth to medical tourism. health and medical tourism are the fastest growing segments in not only developed nations but in developing countries too. india has become a hot destination, as the indian medical standards match up to the highly prescribed international standards at a very low cost. however, it is an unmixed blessing ; along with advantages, it has many unintended side effects also. |
the us food and drug administration (fda) adverse event reporting system (faers, formerly aers) is a database that contains information on adverse event and medication error reports submitted to the fda 1 - 3. the database is designed to support the fda 's post - marketing safety surveillance program for drug and therapeutic biologic products 1 - 3. its structure adheres to the international safety reporting guidance issued by the international conference on harmonisation, ich e2b 1 - 3. adverse events and medication errors are coded using terms in the medical dictionary for regulatory activities (meddra) terminology 4. the reports from manufacturers are either expedited, which must be submitted within 15 days, or periodic 1 - 3. reports can also be submitted by health care professionals and the public through the medwatch program 1 - 3. the original system was started in 1969, but since the last major revision in 1997, reporting has markedly increased 5, 6. to date, the faers is the largest repository of spontaneously reported adverse events in the world with more than 4 million reports 5, 6. the fda releases the data to the public, and public access offers the possibility to external researchers and/or pharmacovigilance experts to explore this data source, that is, allows conducting pharmacoepidemiological studies and/or pharmacovigilance analyses. pharmacoepidemiology is defined as the study of the use and effects of drugs in large numbers of people, whereas pharmacovigilance is the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other drug - related problems 7 - 9. the faers database is useful for analyzing associations with adverse events, but if used for pharmacovigilance, where early and timely detection is important 10 - 13, has two major deficiencies 14 - 16 : the lag time from collection to public release of the data, and the form in which the data are released, i.e., ascii or smgl files, which is not readily amenable to query or analysis 14 - 16. additionally, spontaneous reports can have missing data, and more than 2 reports can be submitted for one patient (duplicated reports) 17. through an attempt to address these shortcomings, a novel system, named the czeekv system, has been developed by dr., japan, and we have employed to evaluate the safety profiles of several drugs 18 - 26. data mining algorithms are applied for the quantitative detection of signals 17, 27 - 30, where a signal means a statistical association between a drug and an adverse event or a drug - associated adverse event, including the proportional reporting ratio (prr) 31, the reporting odds ratio (ror) 32, the information component (ic) given by a bayesian confidence propagation neural network 33, and the empirical bayes geometric mean (ebgm) 34. in this article, the 4 methods will be compared in terms of the signal contents, and the latest information on this area is summarized for future investigations. a data set consists of 7 data tables ; patient demographic and administrative information (demo), drug / biologic information (drug), adverse events (reac), patient outcomes (outc), report sources (rpsr), drug therapy start and end dates (ther), and indications for use / diagnosis (indi). the drugs in the drug table are assigned as any of primary suspect, secondary suspect, concomitant, or interacting. the adverse events in the reac table are coded using the preferred terms (pts) in the meddra. it should be noted that there are a number of duplicated entries and the data occasionally contain misspelling and miswords. in our previous reports 18 - 26, input data were taken from the public release of the faers database from the first quarter of 2004 through the end of 2009, and the total number of reports used was 2,231,029. prior to data mining, duplicated reports were deleted according to the fda 's recommendation of adopting the most recent case number, resulting in a reduction in the number of reports from 2,231,029 to 1,644,220. several adverse events coded by pt terms and several drugs can be listed in a report. all drug names were unified into generic names by a text - mining approach, because faers permits the registering of arbitrary drug names, including trade names and abbreviations. spelling errors were detected by a spell checker software, gnu aspell, and carefully confirmed by working pharmacists. foods, beverages, treatments (e.g. x - ray radiation), and unspecified names (e.g. beta - blockers) were omitted for this study, and the total number of omissions was 164,384. consequently, a total of 22,017,956 co - occurrences were found in 1,644,220 reports, where a co - occurrence was a pair of a drug and an adverse event, and they were the basis for the signal detection. of the 1,644,220 reports used for data mining, gender data were available for 1,520,994 (92.5%) ; 605,271 (36.8%) for males and age data were available for 1,084,999 reports (66.0%), and the average (sd) was 52.723.2 years. data mining algorithms have been developed to identify drug - associated adverse events (signals) that are reported more frequently than expected by estimating expected reporting frequencies on the basis of information on all drugs and all events in the database 17, 27 - 30. for example, prr 31, ror 32, ic 33, and ebgm 34 are widely used, and indeed, currently employed by the medicines and healthcare products regulatory agency (mhra), uk, the netherlands pharmacovigilance centre, the world health organization (who), and the fda, respectively. all of these algorithms calculate signal scores, i.e., the values for prr, ror, ic, and ebgm, to assess whether a drug is significantly associated with an adverse event or not. these calculations or algorithms, so - called the disproportionality analyses or measures, however, differ from one another in that the prr and ror are frequentist (non - bayesian), whereas the ic and ebgm are bayesian. a two - by - two contingency table is the framework for analysis (table 1). the number of co - occurrences with a drug of interest, but without an adverse of interest, is defined as n10, and the number n01 is assigned to those without a drug of interest, but with an adverse event of interest. the number of co - occurrences without either is as n00, and using them, the prr and ror are defined as : the expected number of co - occurrences of interest, n11(expected), is defined as : the observed - to - expected ratio, n11/n11 (expected), is used for calculation of the ic and ebgm. the ic is a logarithmic metric of n11/n11 (expected) that is implemented in a bayesian framework, and n11/n11 (expected) is known as the ebgm, when implemented within an empirical bayesian framework. in this section, the reader is referred to the articles for more extensive details on each statistical test 31 - 34. using the prr, a signal is detected if the number of co - occurrences is 3 or more and the prr is 2 or more with an associated value of 4 or more 31. for the ror, a signal is detected, if the lower limit of the 95% two - sided confidence interval exceeds 1 32. signal detection using the ic is done using the ic025 metric, a lower limit of the 95% two - sided confidence interval of the ic, and a signal is detected if the ic025 value exceeds 0 33. finally, for the ebgm, the eb05 metric, a lower one - sided 95% confidence limit of the ebgm, is used and a signal is detected when the eb05 is greater than or equal to the threshold value 2.0 34. in our studies 18 - 26, these 4 methods were used to detect signals, and the adverse events were listed as drug - associated, when at least 1 of 4 indices met the criteria indicated above. in 2003, the pharmaceutical research and manufacturers of america - fda collaborative working group on safety evaluation tools, consisting of statisticians, pharmacoepidemiologists, and pharmacovigilance professionals from the pharmaceutical industry and the fda, reviewed the best practices for the use of these methods 28. in summary, they stated that there is evidence that data mining may be useful, but the evidence is not sufficient to fully judge the value of data mining in pharmacovigilance, and that time and experience will reveal the value and utility 28. it is important to understand both the strengths and weaknesses of data mining algorithms to minimize their misapplication and misuse 27. we recommend that readers refer to the many excellent review articles on data mining algorithms published previously 17, 27 - 30. in table 2, an example of output data is provided to both familiarize readers with the analysis and show the differences between the 4 signal scores. these data are on the warfarin-, aspirin- and clopidogrel - associated haematemesis, and those on haemorrhage, haematoma, melaena and haematochezia have already published previously 26. the total number of warfarin - associated adverse events was 736, and 848 for aspirin and 838 for clopidogrel 26. according to the number of co - occurrences, haematemesis ranked 56 among 736 warfarin - associated adverse events, 13 among 848 aspirin - associated ones, and 61 among 838 clopidogrel - associated ones. the number of co - occurrences is an important index for monitoring the emergence of an adverse event, but is independent of the signal scores and/or performance of detection of signals. for example, haematemesis ranked 559, 375, and 581, respectively, according to the ror score. moreover, it should be noted that whether an adverse event is detected as a signal or not depends on the algorithm used for signal detection. indeed, as shown in table 2, based on the ror and ic, the analysis indicated the association of these 3 drugs with haematemesis ; however, it was not associated with warfarin when the prr was used, and the ebgm failed to detect the associations for warfarin and clopidogrel. the relationships between the 4 algorithms and numbers of signals are summarized in table 3. this table was constructed using the data in our previous reports 19, 20, 22 - 26. among the 4 methods, the ror provided the highest number of signals, and the ebgm the lowest. the difference in the number of signals can be explained by a higher rate of false positives or a lower ability to detect the signals. without standards, one can not know which the case is. additionally, an analysis was done here using the data on warfarin, aspirin and clopidogrel, and it was indicated that all ebgm - based signals were included in the prr - based signals, and also in the ic- or ror - based ones, and that the prr- and ic - based signals were in the ror - based ones. in other words, the ror - based signals could be stratified into 5 groups ; the signals detected by the ror only, the signals detected by the ror and prr, the signals detected by the ror and ic, the signals detected by the ror, prr, and ic, and the signals detected by the 4 methods. if this relationship will be confirmed for other drugs, it can be concluded that the ebgm is the most conservative algorithm. several studies have compared data mining algorithms 32, 35 - 40 ; however, as bate and evans recently concluded 17, the different algorithms have slightly different properties and consequently one might be preferable in a particular application. if used for pharmacovigilance, the data mining algorithms should be assessed from the standpoint of early and timely signal detection 10 - 13. compared the timing of early signal detection with the prr, ror, ic and ebgm using the faers database, and concluded that the ror showed the better performance 10. several strategies have been proposed to increase the power to detect signals, and consequently to heighten pharmacovigilance, including integration with other databases 41 and removing already known drug - event associations 42. detecting signals not described in the prescribing information for a drug at the time of its approval, but supported by published evidence for an association (unlabeled supported signals), is important, and a high rate of detection of unlabeled supported signals is attained by data mining using higher level terms than the pt, i.e., the hlt or the standard meddra queries (smq), a group of pt terms 43. new statistical methodologies will be continuously developed 44, 45, and therefore we will not be able to draw a conclusion concerning which is best for some time. prior to discussion, it is important to elucidate the difference in the table of adverse events listed as drug - associated. it is well - accepted that a randomized, prospective, large - scale and long - term clinical trial is the best way to assess the association between a drug and an adverse event ; however, such trials are not practical due to great expenses of time and cost, especially for rare but clinically important adverse events 46, 47. data mining of the faers database might provide previously unknown, but clinically important associations, and give us useful suggestions to guide clinical decision making. additionally, the faers database might be a useful tool for pharmaceutical companies ' post - marketing activities 48, and given an association between pre - marketing data and post - marketing signal 49, the database might provide constructive suggestions about the method of pre - marketing data collection. our studies suggested that faers data mining reproduced some well - established clinical associations, including cisplatin and nephrotoxicity 19, carboplatin and myelosuppression 19, oxaliplatin and peripheral sensory neuropathy 19, capecitabine and hand - foot syndrome 22, statins and muscular events 23, proton pump inhibitors and hypomagnesaemia 25, and antiplatelets and bleeding complications 26. these results indicate the usefulness of the database and algorithms used, but do not certify an ability to provide previously unknown, but clinically important associations. in 2003, an editorial comment concerning the efficacy and safety of a drug, published in a respected scientific journal, had a considerable impact, since it claimed that no reliable data were provided by a manufacturer 50. debate about this issue continued in the journal until meyboom and edwards concluded that there was a need to improve and accelerate pharmacovigilance 51. the faers database relies on reports not only from manufacturers but also from health care professionals and the public, and one advantage is that the database includes end - user assessments. the coding of adverse events and medication errors using the pt terms in the meddra has considerable advantages. for example, the terminology used to describe statin - associated muscular symptoms varies and therefore the incidence varies among reports 52, 53. the national lipids association 's muscle expert panel and other statin experts have emphasized the importance of standardizing related terms to allow reliable comparisons among studies and to improve care for statin users 53. this does not apply only to statins, and the employment of meddra ensures higher quality results. in 2009, a pilot study performed by hochberg. concerning drug - versus - drug comparisons found the rank - order of adverse event rates in the faers database to be consistent with the results of published studies, encouraging the use of the database for comparisons 54. the number of reports with or without normalization by usage or sales during the corresponding period was used to compare drugs 55, but adverse events are underreported (discussed later), which might lead to incorrect conclusions 46, 47, 56, 57. to date, we have no evidence that the signal scores can be used to determine the rank - order of drugs in terms of risk. indeed, they were calculated for several drugs in the same class, but a discussion about the difference in susceptibility to adverse events was pending 58 - 61. the rate of reporting can vary with the particular adverse event 1, but averages just 6% 62. various factors can be determinants of underreporting, but the knowledge and attitude of health professionals seem to be most important 63. indeed, educational intervention was shown to improve the rate of reporting 64, 65. a patient - targeted survey found that 87% of patients spoke to their physicians about a possible connection, but the physicians were more likely to exclude than affirm the possibility 66. pharmacists, nurse practitioners, and physician assistants play an important role 67, 68, and more publicity for the faers database and/or education should be considered to promote patient reporting 69. even though the reporting rate has dramatically improved, the faers database is still not appropriate for estimating incidence rates, due to the absence of a denominator 1. the number of reports and signals, and the signal scores are influenced by various factors. the number of reports increases over the first 2 years after launching, and then starts going down 5, 6. this is known as the weber effect 70, although it is not always observed 71. the number of signals and signal scores also possibly fluctuate during several years after launching, and the number of unlabeled supported signals depends on the time window after launching 72. generally speaking, reporting can be accelerated after a drug - associated adverse event is highlighted 73 - 75, and this is known as the notoriety effect 74. additionally, the notoriety for a drug can accelerate the reporting of other drugs in the same class, known as the ripple effect 74. in contrast, signal scores can be suppressed by a large number of reports in which the same adverse event is connected with other drugs 76. close attention should be paid to the results of signal detection, especially for drugs launched only recently, and it is important to investigate a temporal axis, when planning a pharmacovigilance analysis 73. it should be noted that there is no credible counterfactual means, e.g., a randomized control group, to list signals, and therefore disease - oriented adverse events can be listed also. for example, 238 colistin - associated adverse events included sepsis, pseudomonas infection, acinetobacter infection, and influenza - like illness 20. generally, the results can be biased by unmeasured confounding factors ; e.g., the association of a drug with an adverse event might be explained by those of other drugs which are often co - administered. although a comparison of drugs in the same class can offset confounding factors, enabling drug - versus - drug comparisons, a statistically well - organized methodology should be established to minimize their effects. the data mining algorithms are designed to identify bivariate associations, and the possibility that an adverse event occurred synergistically with more than 2 drugs is excluded. have recently analyzed the possibility of multi - item adverse event associations, i.e., associations relating multiple drugs to possibly multiple adverse events 77. multi - item associations are rarely reported but are important because they can indicate drug - drug interactions, and a total of 1,167 multi - item associations were identified using 162,744 reports 77. signal scores after stratification by the presence or absence of co - administration might provide information about the drug - drug interaction. additionally, the highly suspicious drugs to induce some serious adverse events are listed by analyzing the faers database, including torsades de pointes 78, 79 and stevens - johnson syndrome / toxic epidermal necrolysis 80. several organizations maintain their own well - organized databases of spontaneously reported adverse events, and use them to analyze associations with drugs. the who programme for international drug monitoring, starting in 1968, is a cornerstone of world - wide pharmacovigilance, and the uppsala monitoring centre, uppsala, sweden, maintains the who global individual case safety report database, vigibase 81 - 84. in france, pharmacovigilance activities are carried out by 31 regional centers based in clinical pharmacology departments of university hospitals 85, 86, and the french pharmacovigilance database has been used to analyze the safety profiles of various drugs 87 - 91. additionally, two european databases, that is, the general practitioners research database (gprd) in the uk, and the pharmo record linkage system in the netherlands, are also frequently used for analytical studies 92. in the near future, a device or infrastructure enabling real - time analysis at a doctor 's office or by a patient will be provided by information technology service companies. data mining does not provide sufficient evidence on causality, and merely suggests the necessity for well - organized clinical studies with respect to associations. the who defines a signal as reported information on a possible causal relationship between an adverse event and a drug, the relationship being unknown or incompletely documented previously 7, 8 ; however, considerable ambiguity remains in the definition in reports 93 - 95. used the faers database to list drugs liable to induce torsades de pointes, and thereafter authorized reports were used as references to stratify the signals into expected and unexpected signals 78, 79. torsades de pointes is considered a designated medical event, i.e., a low - probability event with drug - attributed risk, and a case - by - case analysis is of primary importance 40. as for unexpected signals, they emphasized the necessity for further investigation and close surveillance 78, 79. a debate recently published in a respected journal indicates both the advantages and limitations of data mining of spontaneously reported adverse event databases 96, 97. de boer emphasized that the disproportionality measures as used in spontaneous reporting databases have important limitations and more advanced way might generate new relevant knowledge worth publishing 96. in contrast, montastruc. commented that none of the methods (e.g., case - control studies and cohort studies), if taking alone, should be considered as definitive for evaluating drug risk, and disproportionality studies appear to be important today, due to a growing demand for safer drugs 97. a report in the faers database is a story, sometimes only a rumor, but numerous reports can reflect reality. with larger numbers of faithful reports, the faers database and other spontaneously reported databases should help to optimize pharmacotherapy. | the us food and drug administration (fda) adverse event reporting system (faers, formerly aers) is a database that contains information on adverse event and medication error reports submitted to the fda. besides those from manufacturers, reports can be submitted from health care professionals and the public. the original system was started in 1969, but since the last major revision in 1997, reporting has markedly increased. data mining algorithms have been developed for the quantitative detection of signals from such a large database, where a signal means a statistical association between a drug and an adverse event or a drug - associated adverse event, including the proportional reporting ratio (prr), the reporting odds ratio (ror), the information component (ic), and the empirical bayes geometric mean (ebgm). a survey of our previous reports suggested that the ror provided the highest number of signals, and the ebgm the lowest. additionally, an analysis of warfarin-, aspirin- and clopidogrel - associated adverse events suggested that all ebgm - based signals were included in the prr - based signals, and also in the ic- or ror - based ones, and that the prr- and ic - based signals were in the ror - based ones. in this article, the latest information on this area is summarized for future pharmacoepidemiological studies and/or pharmacovigilance analyses. |
chronic kidney disease (ckd) is already considered a pandemic. in view of the radical changes in habits and lifestyle, as well as of the aging of the population, all of which occurred mainly in the late 20th century and early 21st century, the rates of ckd - related morbidity and mortality have increased significantly and are expected to continue to grow in the years to come. patients with ckd have a weakened immune system as a result of the chronic inflammatory state caused by renal replacement therapies, as well as of ckd itself and other comorbidities. therefore, patients with ckd, regardless of being on renal replacement therapy, are more susceptible to infectious diseases, among which is tuberculosis. tuberculosis is also recognized as a global public health problem, the control of which has been a challenge to various governmental and non - governmental organizations worldwide. in recent years, brazil has seen a decrease in the number of tuberculosis cases, in tuberculosis incidence rates, and in mortality from tuberculosis. the country has also made advances in the detection of the disease and in the management of cases of co - infection with hiv and drug resistance. however, there are still major obstacles that make it impossible for brazil to eliminate tuberculosis, such as limitations in contact investigation and in diagnosing tuberculosis in primary care, as well as the low cure rate among the patients treated. patients with ckd are recognized to be at increased risk for tuberculosis and, because of their state of immunosuppression, they also have poor outcomes during treatment. in brazil, there is a large and growing population of subjects with chronic noncommunicable diseases, among which is ckd, as well as a high prevalence of tuberculosis in the general population and in high - risk groups. therefore, in view of the convergence of these two pandemics and the evidence of occurrence of poor outcomes in this population, we believe that investigations on the subject have not yet been exhausted and that studies are needed to identify the characteristics related to unfavorable outcomes, taking the differences among the possible outcomes into consideration, given that such outcomes imply control measures with different degrees of complexity. the objective of the present study was to examine the association between clinical / epidemiological characteristics and outcomes of tuberculosis treatment in patients with concomitant tuberculosis and ckd by using multivariate analysis and multinomial logistic regression. the sistema de informao de agravos de notificao (sinan, national case registry database) is one of the health surveillance systems of brazil, having been developed in the 1990s with the purpose of collecting and disseminating information that, in cases of tuberculosis, include sociodemographic data, health history, and characteristics of the disease and its treatment. analysis of completeness and quality of the information generated have been carried out over the years, this database being considered an important and reliable source of information. between 2007 and 2011, a total of 432,958 tuberculosis cases were reported to the sinan in brazil, and of those patients, 1,716 were reported as also having ckd (tb - ckd). therefore, tuberculosis treatment outcomes (cure, treatment abandonment, death from tuberculosis, and death from other causes) were compared with clinical / epidemiological characteristics in tb - ckd patients. the tb - ckd patients for whom treatment completion status was inconclusive (unknown, transfer, or change in diagnosis) or who developed multidrug resistant tuberculosis were excluded from the study. a tb - ckd patient was defined as that for whom the field called " other comorbidities " in the sinan database was filled with words describing ckd, regardless of its stage. therefore, the following descriptions were found and included : chronic kidney disease ; chronic renal failure ; chronic nephropathy ; chronic glomerulonephritis ; chronic renal patient ; hemodialysis ; renal transplantation ; kidney transplantation ; dialysis - induced renal failure ; and renal patient on dialysis. the sociodemographic variables were as follows : gender (female / male) ; age (12 years / not applicable) ; residence (urban or peri - urban / rural) ; and institutionalization (no / prison / nursing home / orphanage / psychiatric hospital / others). health history included presence / absence of alcoholism, diabetes mellitus, mental illness, aids, and renal transplantation. in addition, we analyzed the following variables related to the characteristics of tuberculosis and its treatment : type of case (new case / recurrence / readmission after treatment abandonment / transfer) ; tuberculin skin testing (negative / weakly positive / strongly positive) ; chest x - ray (normal / suspicious) ; initial smear (sputum or other samples ; negative / positive) ; follow - up smear at 2 months (sputum ; negative / positive) ; culture (sputum or other samples ; negative / positive) ; histopathological examination (positive for afb / suggestive of tuberculosis / not suggestive of tuberculosis) ; presentation of tuberculosis (pulmonary / extrapulmonary / pulmonary + extrapulmonary) ; occupational disease (yes / no) ; indications for directly observed treatment, short - course strategy (dots ; yes / no) ; and use of dots (yes / no). proportions were compared with pearson 's chi - square test or the likelihood ratio, and the variables associated with the outcome of interest (p 12 anos / no se aplica) ; rea de residncia (urbana ou periurbana / rural) ; e institucionalizao (no / presdio / asilo / orfanato / hospital psiquitrico / outros). quanto ao histrico de sade, foram analisadas a presena / ausncia de alcoolismo, diabetes mellitus, doena mental, aids e transplante renal. tambm foram analisadas as seguintes variveis relacionadas s caractersticas da tuberculose e de seu tratamento : tipo de tratamento (caso novo / recidiva / reingresso aps abandono / transferncia) ; prova tuberculnica (no reator / reator fraco / reator forte) ; radiografia de trax (normal / suspeito) ; baciloscopia de escarro ou de outros materiais inicial (negativa / positiva) ; baciloscopia de escarro de acompanhamento no segundo ms (negativa / positiva) ; cultura de escarro ou de outros materiais (negativa / positiva) ; exame histopatolgico (baar positivo / sugestivo de tuberculose / no sugestivo de tuberculose) ; forma da tuberculose (pulmonar / extrapulmonar / pulmonar + extrapulmonar) ; doena adquirida no trabalho (no / sim) ; indicao de tratamento diretamente observado (tdo ; no / sim) ; e realizao de tdo (no / sim). o teste do qui - quadrado de pearson ou a razo de verossimilhana foram utilizados na comparao das propores, e as variveis associadas com o desfecho de interesse (p < 0,10) foram includas a regresso logstica multinomial uma tcnica til para modelar simultaneamente probabilidades de desfechos com mltiplas categorias. na presente anlise, " cura " foi a categoria utilizada como referncia para a varivel resposta, sendo essa comparada com as demais categorias (cura vs. abandono ; cura vs. bito por tuberculose ; e cura vs. bito por outras causas). a partir de um modelo conceitual de determinao da tuberculose e para dar conta das inter - relaes existentes entre esses determinantes, foram definidos trs nveis hierrquicos : no primeiro nvel foram includas as variveis sociodemogrficas ; no segundo nvel foram includas as variveis mantidas no nvel 1 (p < 0,10) e as comorbidades ; e no terceiro nvel foram includas as variveis mantidas no nvel 2 (p < 0,10) e aquelas relacionadas s caractersticas da tuberculose. realizadas com o programa estatstico stata, verso 12.0 (statacorp lp, college station, tx, eua). o presente estudo foi aprovado pelo comit de tica em pesquisa do centro de cincias da sade da universidade federal do esprito santo sob o nmero 121/06. entre os anos de 2007 e 2011, a prevalncia de drc entre os casos de tuberculose registrados no sinan foi de 0,4% (ic95% : 0,37 - 0,42%). os desfechos nessa amostra foram os seguintes : cura, em 628 indivduos (58,3%) ; abandono do tratamento, em 79 (7,4%) ; bito por tuberculose, em 137 (12,7%) ; e bito por outras causas, em 233 (21,6%). apenas 1 indivduo evoluiu para tuberculose resistente a mltiplas drogas e, por isso, foi excludo das anlises subsequentes. foram excludos ainda 638 indivduos com os seguintes desfechos : ignorado, em 476 ; transferncia, em 145 ; e mudana de diagnstico, em 17. a proporo de indivduos classificados como curados aps o tratamento da tuberculose foi menor entre aqueles com idade 60 anos (p < 0,001). em contrapartida, no foram encontradas diferenas significativas na distribuio das variveis gnero, cor da pele, escolaridade e rea de residncia em relao aos desfechos (tabela 1). tabela 1distribuio das caractersticas sociodemogrficas de indivduos com doena renal crnica e notificados com tuberculose no sistema de informao de agravos de notificao segundo o desfecho do tratamento da tuberculose, brasil, 2007 - 2011.a na tabela 2, verificamos que a mortalidade por tuberculose e por outras causas foi alta entre os indivduos identificados como alcoolistas (24,1% e 31,0%, respectivamente). diabetes mellitus, doena mental e aids foram comorbidades menos prevalentes entre aqueles que tiveram o desfecho de cura. tabela 2distribuio das comorbidades de indivduos com doena renal crnica e notificados com tuberculose no sistema de informao de agravos de notificao segundo o desfecho do tratamento da tuberculose, brasil, 2007 - 2011.a as principais caractersticas clnicas da tuberculose e de seu tratamento encontram - se na tabela 3. entre aqueles indivduos que iniciaram um novo tratamento aps o abandono, o desfecho foi de cura, em 22,6% ; abandono, em 32,2% ; bito por tb, em 22,6% ; e bito por outras causas, em 22,6% (p < 0,001). tabela 3distribuio das caractersticas clnicas de indivduos com doena renal crnica e notificados com tuberculose no sistema de informao de agravos de notificao segundo o desfecho do tratamento da tuberculose, brasil, 2007 - 2011.a diferenas significativas foram encontradas nas distribuies da forma de apresentao da doena entre os desfechos do tratamento (p = 0,004). a forma concomitante da doena (pulmonar + extrapulmonar) apresentou uma menor proporo entre os indivduos curados (46,4%) do que as formas pulmonar e extrapulmonar (58,4% e 60,4%, respectivamente). tanto para a indicao quanto para a realizao de tdo houve diferena na distribuio das propores (p = 0,005 e p = 0,029, respectivamente). para a anlise multivarivel de regresso logstica multinomial, o modelo hierrquico foi definido da seguinte forma : no nvel 1, idade ; no nvel 2, diabetes, alcoolismo, doena mental, aids e transplante renal ; e no nvel 3, tipo de tratamento, radiografia de trax, baciloscopia inicial, forma da doena, indicao de tdo e realizao de tdo. a varivel prova tuberculnica, apesar de estatisticamente significativa, no foi includa no modelo devido baixa proporo de exames realizados. verificou - se que, se comparados ao desfecho cura, indivduos tb - drc com idade 60 anos apresentaram menor or para abandono (or = 0,28 ; ic95% : 0,10 - 0,74) do que aqueles com menos de 20 anos. tabela 4anlise multivarivel de regresso logstica multinomial com modelo hierrquico de covariveis sociodemogrficas e clnicas associadas com o desfecho do tratamento da tuberculose em indivduos com doena renal crnica e notificados com tuberculose no sistema de informao de agravos de notificao segundo o desfecho do tratamento da tuberculose, brasil, 2007 - 2011. quanto s comorbidades, em relao ao desfecho cura, o alcoolismo foi associado tanto ao bito por tuberculose (or = 3,38 ; ic95% : 1,63 - 6,97) quanto ao bito por outras causas (or = 2,30 ; ic95% : 1,18 - 4,47). a presena de aids tambm esteve associada com bito por outras causas (or = 3,32 ; ic95% : 1,68 - 6,58). o reingresso aps o abandono do tratamento apresentou uma or de 16,08 (ic95% : 5,41 - 47,82) para abandono em relao cura, se comparado aos casos novos (referncia), e de 4,82 (ic95% : 1,53 - 15,21) para bito por tuberculose em relao cura. os indivduos com indicao de tdo apresentaram uma or menor para abandono em relao cura (or = 0,33 ; ic95% : 0,12 - 0,92), mas uma or maior para bito por outras causas em relao cura (or = 1,71 ; ic95% : 1,03 - 2,85). por outro lado, aqueles que realizaram tdo apresentaram uma or menor para bito por tuberculose (or = 0,44 ; ic95% : 0,22 - 0,90), mesmo aps o controle para as demais variveis includas no modelo. a relao entre tuberculose e drc vem sendo estudada ao longo dos anos. o maior risco para o desenvolvimento de tuberculose entre os indivduos portadores de drc em estgio terminal j foi descrito em diversos estudos, podendo esse risco ser at 37 vezes maior naqueles cuja terapia de substituio renal o transplante e de 10 a 25 vezes maior naqueles sob hemodilise. entretanto, desconhecemos estudos que, entre indivduos portadores de tuberculose ativa, tenham avaliado a prevalncia de drc, independentemente da realizao de terapia de substituio renal. o fato de terem sido avaliadas as associaes entre a tuberculose, um j antigo problema global de sade pblica, e a drc, um dos novos desafios deste sculo, refora a importncia e a pertinncia do presente estudo. a prevalncia de indivduos tb - drc pode ter sido subestimada, pelo fato de essa informao no ser de preenchimento obrigatrio e depender do relato dos pacientes na hora da notificao, havendo, assim, a possibilidade de um vis de classificao, pelo qual indivduos com drc tenham sido classificados como sem drc. no entanto, tambm importante ressaltar que esse fato no interfere nas associaes encontradas, uma vez que o relato de drc no est relacionado com as variveis estudadas. apesar de estudos ressaltarem o sinan como uma fonte confivel de informaes sobre a tuberculose, esses estudos apontam para limitaes de completude de variveis e para a subnotificao de casos e mortes por tuberculose. dessa forma, tambm se verificou a existncia de indivduos com informaes ignoradas ou inconsistentes em algumas variveis estudadas, e optamos por no exclu - las por conta do poder estatstico do estudo. nossos resultados mostraram que as caractersticas associadas com o abandono do tratamento da tuberculose foram os estratos etrios, o retorno para o tratamento aps abandono prvio e a indicao de tdo. as caractersticas associadas com o bito por tuberculose foram a presena de alcoolismo, o retorno para o tratamento aps abandono prvio, a presena de resultado suspeito para tuberculose em radiografia de trax e a realizao de tdo. j as caractersticas que diferenciam a or de bito por outras causas em relao a cura no tratamento da tuberculose foram os estratos etrios, a presena de alcoolismo, a presena de aids, a transferncia do paciente para outra unidade de tratamento, a baciloscopia de escarro inicial positiva, e a indicao de tdo. a associao entre o envelhecimento e um pior desfecho para o tratamento da tuberculose foi descrita em estudos prvios, indicando que as possveis comorbidades que surgem durante o processo de envelhecimento possuem um papel fundamental no prognstico da tuberculose. a associao com o bito por outras causas em relao cura naqueles indivduos tb - drc com idade 60 anos confirma a importncia das comorbidades nessa populao, bem como nos sugere a possibilidade de uma relao bidirecional entre tuberculose e drc ; portanto, a drc influencia o desfecho da tuberculose, assim como a tuberculose influencia o desfecho da drc, conforme acontece com outras doenas crnicas no transmissveis. ainda em relao idade, destaca - se uma menor or para o abandono em relao cura para aqueles acima de 20 anos. esse dado diz a favor da qualidade do cuidado prestado pelas equipes de nefrologia do brasil, que geralmente optam por um acompanhamento prximo de seus pacientes e adotam estratgias que promovam a adeso para o tratamento conservador, as terapias dialticas ou o transplante renal, cujos resultados positivos podem ser extrapolados para o tratamento da tuberculose. o alcoolismo, outro importante e muito estudado fator de risco para tuberculose, tambm aumentou a or para bito tanto por tuberculose quanto por outras causas em nosso estudo, o que indica uma necessidade urgente de modificao das estratgias de ao voltadas para o controle do alcoolismo, pautando - as em medidas que deem conta da determinao social da tuberculose. apesar dos grandes avanos alcanados com as colaboraes entre os programas para o controle da tuberculose e para o controle de hiv / aids, a infeco por hiv / aids continua aumentando o risco para um pior desfecho em indivduos com tuberculose, o que tambm foi verificado em nosso estudo. uma recente reviso sistemtica e meta - anlise sugere que, para esses indivduos, o tratamento da tuberculose deva ser estendido por um perodo maior do que 8 meses para a melhora do desfecho. embora no tenhamos verificado diferenas estatisticamente significativas na distribuio de institucionalizao entre os desfechos, h registros de que a tuberculose a principal causa de morte na populao encarcerada em pases em desenvolvimento. ainda, nesses indivduos, o diagnstico da tuberculose geralmente tardio, e h grandes dificuldades de adeso ao tratamento. indivduos que retornaram ao tratamento aps o abandono, em um estudo realizado na cidade de campinas na dcada de 1990, apresentaram uma maior proporo de novo abandono do tratamento bem como de morte por tuberculose em comparao a casos novos, resultado esse semelhante ao encontrado em nosso estudo. a positividade de baciloscopia de seguimento tem sido relacionada com um desfecho desfavorvel para o tratamento da tuberculose. no foi verificada essa associao em nosso estudo, mas o alto ndice de exames no realizados em nossa amostra, assim como o fato de que aproximadamente 40% dos indivduos apresentavam tuberculose extrapulmonar, uma vez que h uma menor positividade na baciloscopia nessa forma clnica, podem ter influenciado esse dado. em resposta s dificuldades para a aderncia ao tratamento da tuberculose e para enfrentar as graves consequncias no desfecho de um tratamento subsequente, algumas estratgias tm sido adotadas com o objetivo de influenciar o comportamento dos profissionais de sade, a organizao dos servios e tambm o comportamento daqueles com suspeita ou diagnstico de tuberculose. a estratgia de tdo lanada pela organizao mundial de sade, apesar de ainda ser muito controversa, alcanou resultados positivos, auxiliando o controle da doena em diversas partes do mundo. na populao estudada, os indivduos que estiveram sob o tdo apresentaram uma or menor para bito por tuberculose, indicando que o tdo reduziu a or de ocorrncia de um desfecho negativo da tuberculose. dessa forma, o desfecho desfavorvel para o tratamento da tuberculose no se mostrou relacionado com as caractersticas da tuberculose em nosso estudo. as principais associaes com o abandono e bito estiveram relacionadas com caractersticas acreditamos que, para o brasil, pas que possui um abrangente e reconhecido programa de controle da tuberculose, nossos dados indicam a importncia das caractersticas sociodemogrficas na determinao da tuberculose em indivduos com drc e reforam a necessidade de estratgias de controle direcionadas a determinados grupos populacionais, priorizando principalmente os portadores de doenas crnicas no transmissveis, como a drc. | objective : to analyze the association between clinical / epidemiological characteristics and outcomes of tuberculosis treatment in patients with concomitant tuberculosis and chronic kidney disease (ckd) in brazil. methods : we used the brazilian ministry of health national case registry database to identify patients with tuberculosis and ckd, treated between 2007 and 2011. the tuberculosis treatment outcomes were compared with epidemiological and clinical characteristics of the subjects using a hierarchical multinomial logistic regression model, in which cure was the reference outcome. results : the prevalence of ckd among patients with tuberculosis was 0.4% (95% ci : 0.37 - 0.42%). the sample comprised 1,077 subjects. the outcomes were cure, in 58% ; treatment abandonment, in 7% ; death from tuberculosis, in 13% ; and death from other causes, in 22%. the characteristics that differentiated the ors for treatment abandonment or death were age ; alcoholism ; aids ; previous noncompliance with treatment ; transfer to another facility ; suspected tuberculosis on chest x - ray ; positive results in the first smear microscopy ; and indications for / use of directly observed treatment, short - course strategy. conclusions : our data indicate the importance of sociodemographic characteristics for the diagnosis of tuberculosis in patients with ckd and underscore the need for tuberculosis control strategies targeting patients with chronic noncommunicable diseases, such as ckd. |
aurora - a was discovered in a screen for drosophila mutations affecting the poles of the mitotic spindle function 1. thus, the promoters of the aurora - a gene contain specific elements (cde / chr sequences), which are responsible for transcription at g2 phase of the cell cycle 2 - 4. it has been well documented that activation of aurora - a is required for mitotic entry, centrosome maturation and separation, and g2 to m transition [5.6 ]. interestingly, overexpression of aurora - a is frequently observed in varieties of human cancer, including breast, colorectal, bladder, pancreatic, gastric, ovarian and esophageal cancer 7 - 12. overexpression of aurora - a in fibroblasts resulted in cell transformation, supporting a notion that high levels of this protein are correlated to cell malignancy 13. potential roles of aurora - a in cell transformation were also demonstrated from recent studies that this kinase phosphorylates a breast cancer tumor suppressor brca1 at ser308 14. both proteins are localized on centrosome at the beginning of mitosis 15, suggesting that signaling between these two proteins are crucial for regulation of normal cell cycle. recent studies added a couple of new insight of how aurora - a induces cell transformation. thus, in physiological conditions, aurora - a and its activator collaborate with plk1, polo - like kinase 1, to initiate mitosis. on the other hand, in cells transformed with aurora - a the aurora - a gene locus is located in the 20q13 chromosome region, which is frequently amplified in several different types of malignancies such as breast, colorectal, pancreatic, and bladder cancers 7 - 12. in particular, 20q11-q13 regions are amplified in 40% of breast cancer cell lines as well as in 12 - 18% of primary tumors. aurora - a protein is a member of the ser / thr kinase family, and recent studies have shown that the protein is involved in the g2-m checkpoint and commitment to mitosis 18 - 21. furthermore, it has been demonstrated that aurora - a is inactivated by dna damage at the end of the g2 phase, and overexpression of aurora - a abrogates the g2 checkpoint, resulting in the amplified centrosome and cell transformation 18. significantly, aurora - a is recruited to the centrosome early in the g2 phase and becomes phosphorylated and activated in the centrosome late in the g2 phase 6. deng 's lab demonstrated that ~25% of mouse embryonic fibroblasts (mefs) derived from the brca1 exon 11-deleted mice contains more than two centrosomes, leading to loss of the g2-m checkpoint and aneuploidy 21. in addition, we and others found that brca1 is localized in the centrosome and binds to -tubulin 15,22,23. from these observations interestingly, the aa1314 - 1863 region of brca1 was found to bind to aurora - a directly. mutagenic analysis and phospho - specific antibodies revealed that s308 of brca1 is normally phosphorylated by aurora - a early in the m phase. phosphorylation of brca1 s308 by aurora - a was abolished by treating cells with ionizing radiation. most interestingly, re - expression of the phospho - deficient form of brca1, s308n (n = asn), in brca1-mutated mefs resulted in growth arrest at the g2 phase without any cell stress, indicating that phosphorylation of brca1 s308 is necessary for the transition from g2 to m. these results indicate that an unphosphorylated form of brca1 at s308 is necessary for g2-m checkpoint. these are the first indications of the roles of the physiological levels of brca1 phosphorylation in regulating the cell cycle. additional evidence of brca1/aurora - a interaction is that aurora - a regulates inhibition of centrosome microtubule nucleation mediated by brca1 's e3 ligase activity 24. exogenous overexpression of aurora - a in human cell culture was further studied by transfecting u2os osteosarcome cell line 17. interestingly, in those cells, increased phosphorylation of brca1 s308 was not detected [unpublished results ]. these results suggest that phosphorylation of brca1 s308 may not be necessary for cell transformation. thus, perhaps there is substrate selectivity by aurora - a in physiological and malignant conditions. most prominent discoveries from mmtv - aurora - a transgenic mice are constitutive phosphorylation of mtor ser2448 and akt ser473 in developed mammary tumors 16. mammalian target of rapamycin (mtor) is a protein serine / threonine kinase that controls a broad range of cellular processes. mtor exists in two distinct complexes ; mtor complex 1 (mtorc1) and complex 2 (mtorc2). mtor is phosphorylated at multiple sites, including ser2448, ser2481, thr2446 and ser1261. phosphorylation at ser2448 is mediated by p70 ribosomal s6 kinase (s6k) and occurs predominantly to mtor in mtorc1 25 - 27. its function is involved in many growth - related processes such as translation, ribosome biogenesis, transcription, autophagy and hypoxic adaptation, and is sensitive to rapamycin. other unique components in mtorc2 are rapamycin - insensitive companion of mtor (rictor), mammalian stress - activated protein kinase - interacting protein 1(msin1) and proline - rich repeat protein-5 (prr5) or prr5-like 28 - 33. two major functions have been ascribed to mtorc2, including regulation of akt and cell cycle - dependent organization of actin cytoskeleton. mtorc2 phosphorylates akt at ser473 in its c - terminal hydrophobic motif, which, in conjunction with pdk1-mediated phosphorylation of thr308, confers full activation of akt 34. mtorc2 regulates actin cytoskeleton through a mechanism that involves the small gtpases rho and rac, although the molecular details are largely still unclear 8,35. interestingly, mtorc2 phosphorylates pkc and sgk1 (serum- and glucocorticoid - induced protein kinase 1), and has been implicated in controlling cell size 36 - 39. elevated phosphorylation of mtor ser2448 and akt ser473 in aurora - a transformed cells suggests that aurora - a can potentially regulate two mtor pathways, mtorc1 and mtorc2. since chemical inhibitors of mtor can abolish transformed phenotypes induced by aurora - a 17, it is likely that either or both of mtorc1 and 2 is important for aurora - a transformation. of note, mammary tumor development can be observed only after long latency in mmtv - aurora - a mice 16. in cell culture system of stable transfectants, cells in early passage numbers do not contain phosphorylated mtor and akt, but cells after long passage numbers they show up 17. as one possible interpretation, overexpression of aurora - a is not a strong driving force, but some additional events need to happen to accelerate aurora - a 's tumor development. when mtor pathway is activated under this situation, cells now acquire the full - transforming ability. levels of the protein increases in late g2 phase, and decreases during mitotic exit 40. kinase activity well correlates with levels of the protein, thus it increases at g2/m transition and reaches at the maximal during mitosis. similar to plk1, levels of aurora - a increase during g2 and reach at the maximal in early mitosis 13,41. ' activator ' proteins for aurora - a have been identified. those include tpx2, ajuba, pak1, hef1 and hbora 6,42 - 47. among these aurora - a interactors, hbora expression peaks during g2 and decreases rapidly during mitosis 48,49. it has also been shown that hbora forms a complex with plk1 in g2 phase 48,50,51. aurora - a 's binding to bora and its subsequent phosphorylation are required for full activation of aurora - a. in addition, both proteins are essential for plk1 activation at the centrosome in g2 phase. in this model, it is thought that bora binding to plk1 induces allosteric effects that allow aurora - a to the plk1 t - loop of its kinase domain, where aurora - a phosphorylates thr210, leading to full activation of plk1 51,52. it has been speculated that aurora - a is a target for ubiquitination by chfr, checkpoint with fha and ring finger domains. chfr regulates an early mitotic checkpoint, during prophase, in response to the disruption of microtubule formation or stabilization as assessed after treatment with microtubule inhibitors such as nocodazole, colcemid and taxanes 53. interestingly, aurora - a was overexpressed in chfr - null mouse embryonic fibroblasts and tissues, strongly supporting that chfr ubiquitinates aurora - a 54. these studies have also demonstrated that the c - terminal cysteine - rich region of chfr protein interacts with the n - terminus of aurora - a protein. similar results were shown from the other studies that sirna - mediated depletion of chfr in mcf10a cells resulted in overexpression of aurora - a 55. it has been demonstrated that, in hct116 cells overexpressing chfr, there was no change in levels of aurora - a and localization of aurora - a to the centrosomes, however, nocodazole - induced chfr - mediated mitotic delay was associated with unphosphorylation of aurora - a at thr288 56. it has been shown that overexpression of chfr mutants which mimic unphosphorylated chfr can decrease levels and kinase activity of plk1 57. interestingly, mouse embryonic fibroblasts from chfr knockout mice express high levels of plk1, suggesting that chfr can ubiquitinate plk1 to target it for degradation 54. given the high frequency of overexpression of aurora - a in human cancers, inhibition of aurora - a with small compounds looks like an attractive cancer - therapeutic strategy. classical cell biology assay, such as transfection of normal fibroblasts with aurora - a cdna, resulted in cell transformation. transgenic model targeting aurora - a in mammary glands also support a notion that this kinase is oncogenic. however, quite long latency and low incidence of tumor development in these mice suggest that aurora - a alone is not a strong driving force of malignancy, but other hits need to occur for full transformation 16. thus, it is possible that inhibition of aurora - a with compounds may not be sufficient for killing aurora cancer cells. chromosome instabilities observed in those mammary tumors support this hypothesis that activation or inactivation of ' effector proteins ' due to the gross alteration of chromosome structure may result in accelerating tumorigenesis (fig. 1). in that sense, simultaneous inhibition of this pathway(s) as well as aurora - a might be necessary for the better treatment of patients. for example, mtor / akt pathway might be the one which is crucial for aurora - a tumorigenesis. | aurora family of protein kinases have emerged as crucial factors of, not only mitosis and cytokinesis, but also human carcinogenesis. among these family members is aurora - a that is frequently overexpressed in varieties of human cancer. both in vitro and in vivo studies demonstrated that aurora - a induces tumorigenesis through genome instability. these studies have further shown that cell signaling cross - talk between aurora - a and other cellular proteins are essential for fully - transformed phenotypes. this review summarizes recent progress of aurora - a - associated carcinogenesis. |
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