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prevalence of both type-1 and type-2 diabetes in children and adolescents is rapidly increasing worldwide. type-2 diabetes is often asymptomatic in its early stages and, thus, it remains unidentified. the risk of such a condition is the same or higher than the previously diagnosed ones. the individuals with impaired fasting glucose (ifg) and/or impaired glucose tolerance (igt) are called prediabetes, which is an intermediate and reversible condition before getting type-2 diabetes. appropriate management of the adolescents susceptible to the abnormal carbohydrate metabolism can have an effective role in preventing or delaying their development of type-2 diabetes in later life and reduce their long - term mortality and morbidity. the american diabetes association (ada) and the american academy of pediatrics have confirmed the screening of children for diabetes, and given the high prevalence of prediabetes in children there is also interest in screening for prediabetes in the pediatric population. there were no data available on the prevalence of t2 dm (type-2 diabetes mellitus) and prediabetes for adolescents in birjand. the authors, therefore, performed a, cross - sectional and descriptive analytical study on secondary and high school students aged 1118 years to ascertain the prevalence of t2 dm and prediabetes in adolescents in birjand. samples were chosen through multistage stratified and random sampling. at first, birjand was divided into five regions based on socioeconomic levels. afterward for each sex, seven secondary and seven high schools were chosen considering the distribution of the schools in different districts of the city. total of 2,800 students were chosen based on a procedure as a subsample was selected from different classes of each school with respect to the population of school and its ratio to the total number of students in that class. after obtaining verbal consent from the selected students, a questionnaire (containing demographic information, age, sex, known diseases, and drugs) along with a consent form the parents were demanded to fill out the questionnaire and the consent form that show their children having not any chronic disease or endocrine disorder such as diabetes or not being on treatment of corticosteriods, and then return completed forms to the school. in this step finally, 2,653 students were referred to a diagnostic clinic and a 12-h fasting blood sugar sample was taken from each for testing. the obtained samples were immediately centrifuged, and applying enzymatic procedure using german rosh kits, their respective sugar levels were determined. the standard by which impairment in fbs would be approved was that of ada, that is, fbs 100 mg / dl but 126 (0.1%) in this study was similar to guerrero. of our population, 7.5% were prediabetics, which is not too high compared to other studies, but it is alarming. in the study by li. prevalence of prediabetes in mysore city in india was 3.7%. in the study of lee, on overweight or obese children, aged 1017 years, 39% cases were prediabetes. the difference in the prevalence of prediabetes in different communities is due to differences in the prevalence of obesity and cardio metabolic risk factors which is caused lifestyle and diet plus ethnic and cultural differences. our results show that mean blood glucose varies according to age [table 1 ]. mean blood glucose at all ages except at 11 years of age was higher in boys between the age range of 11 and 12 years, the trend was a rising one but in girls it was declining. after 12, increasing or decreasing in blood glucose was similar in both sexes, but it occurred sooner in girls. possibly, the variation in blood glucose level at different ages and in both sexes corresponds with pre post puberty hormonal changes. during puberty, rapid and dynamic changes occur in various metabolic systems, such as hormonal regulations, variations in body fat and its distribution, and insulin resistance increasing. insulin sensitivity is highest before the beginning of puberty (tanner stage 1), approaching near prepubertal levels at the end of maturation (tanner stage 5). although this study shows that the population of adolescents with fbs impairment is not high, the relatively high percentage of adolescents with high normal fbs can be predictive of following risk for developing prediabetes and diabetes during youth, middle age, and old age. early identifcation and appropriate management of them can effectively prevent or delay their development of type-2 diabetes in later life. our data highlights the importance of coordinated individual, school- and community - based lifestyle intervention measures aiming at all age groups. intervention programmers are requisite to prevent a type-2 diabetes epidemic in society. in order to study the final outcome of children 's fbs impairment, the positive aspects of this study include a large population sample, representative sampling methodology, and the use of standardized data collection protocols. one of the limitations of this study was that, given the large population of children, re - testing of blood glucose for a definitive diagnosis of patients with diabetes was not possible. screening of all school children is ideal, but given the high cost of general screening it is recommended that measurement of fasting plasma glucose in individuals with risk factors such as obesity should be done, to prevent outbreaks of diabetes and its cardiovascular complications. great efforts may be needed to intervene against the fundamental causes of fbs impairment such as overweight, physical inactivity, and unhealthy diet in pediatric primary care centers and through public health services. | background and objectives : to determine the prevalence of impaired fasting glucose in adolescents in birjand city in eastern iran.materials and methods : this cross - sectional study was done on 2653 students aged 1118 years selected through multi - stage stratified and random sampling. fasting blood glucose (fbs) of these students was measured applying the enzymatic process. the obtained data were analyzed by means of spss software (v : 15) and statistical tests t and x2.results:the mean age of individual was 14.5 2 years. mean fbs of the whole population was 89.8 9.8 mg / dl, but it was significantly higher among boys than girls (p 126 mg / dl. mean blood glucose was significant regarding age and sex.conclusions:high prevalence of high fbs (within normal range) among adolescents is warning and requires special attention of health officials. screening of children and adolescents in order to identify those at risk and plan for intervening is urgent to prevent type-2 diabetes epidemic and following cardiovascular complications in the society |
gbm diffusely infiltrates the surrounding brain tissue, but does not typically invade blood vessels and rarely spreads outside the central nervous system (cns). metastasis to the outside of the cns was accounted for in only 0.2% cases4). the most common site of extraneural metastasis of the gbm is pleura and the lung10,12). although the exact mechanism of extraneural metastasis has been poorly understood, the lymphatic drainage, the venous system and the adjacent dura and bone have been suggested as the three possible routes of extraneural spread2). interestingly, we experienced a rare case of extraneural metastasis of the gbm, presenting as an unusual neck mass. herein, we report this unusual case, with review of the literature, and we suggest the risk factors of extraneural metastasis. a 46-year - old man was referred to our neurosurgical unit complaining of progressive right hemiparesis. at admission, he was alert and fully oriented. neurological examination revealed right hemiparesis (grade 3/5). in the past medical history, he had undergone a craniotomy in the left fronto - parietal region for brain tumor 10 years ago in another hospital. although we could not obtain pathological and medical records, he informed that his brain tumor had been diagnosed as low grade glioma, and he had received radiation therapy following craniotomy. magnetic resonance images (mri) and computed tomography (ct) scan on admission demonstrated a poorly defined heterogenously enhancing mass with extensive peritumoral edema in the left frontal motor cortex (fig. since the mass was located near the previous craniotomy site, we suggested that this tumor might be related with previously diagnosed glioma. under the presumptive diagnosis of secondary tumor, malignant transformation of a low grade glioma or radiation induced glioblastoma the mri scans taken 2 weeks later showed a remnant mass in the left frontal lobe (fig. 3). considering his previous history of radiation therapy, we performed gamma knife radiosurgery for the remnant mass, with a marginal dose of 20 gy to the 50% isodose line, followed by 6 cycles of adjuvant chemotherapy with the pcv regimen (i.e. procarbazine, lomustine, and vincristine). three years later, he presented with progressive weakness of the right extremities and dysarthria. 4a). surgical resection was done for the mass lesion and the histopathological findings revealed recurrence of the gbm. he remained in a stable condition during the 6 cycles of adjuvant chemotherapy with temozolomide. since then, he underwent craniotomy two more times and shunt procedure for the recurrence of the tumor and hydrocephalus for 30 months. five years after the initial diagnosis, a palpable mass lesion was observed on his left side of the neck. the neck ct with contrast enhancement revealed a 34 cm sized round mass, with peripheral rim enhancement in the left side of the neck (fig. mass was biopsied and the histopathology indicated a metastatic deposit of the gbm. at that time, his condition, including consciousness and motor function, worsened, and the brain mri noted the progression of the gbm. we performed the surgical resection of the brain tumor and of the neck mass, simultaneously. the pathological specimens were shown with increased cellularity, with blood vessel proliferation and necrosis (30%). all pathological specimens, from both the brain tumor and the neck mass, were confirmed as gbm (fig. glioblastoma multiforme is one of the most malignant neoplasms in human beings and the most common primary tumor in the cerebral hemisphere. the incidence accounts for 2 to 3 cases/100000 per year in both europe and north america, and 75% of the patients die within 18 months from diagnosis13). gbm commonly spreads by direct extension and infiltration into the adjacent brain tissue and along the white matter tract. although the tumor is associated with a strong tendency for local invasiveness, the metastatic spread of the gbm outside of the cns is extremely rare. thus, the spread outside the cns occurs with a frequency of only 0.2%4). the reason why the gbm rarely metastasizes is still unclear, but some hypotheses have been proposed. the first hypothesis was suggested on the basis of the short life span of patients. the severe aggressiveness of the gbm results in a very short survival period of patients. the second suggestion has been based on the barrier effect of the basement membrane. in in vitro experiments, the capillary basement membrane played an important role as a physical barrier against migration of the glioma cells into the blood stream in the brain1). as another assumption, the cellular environment of the cns also might be related to the prevention of metastasis of the gbm, because the cns lacks extracellular the matrix components, such as collagen and fibronectin, which are overexpressed only in the hyperplastic blood vessels. through hyaluronic acid and other glycosaminoglycans which are main components of the extracellular spaces although the exact mechanism of extraneural metastasis has been poorly understood, cervio.2) suggested three possible mechanisms of extraneural spread, as follows : 1) the lymphatic cerebrospinal fluid drainage into the extraneural tissue (despite absence of an identifiable lymphatic system in the cns) ; 2) the venous invasion, either via the leptomeningeal sinuses or via the intracerebral vein ; 3) direct invasion through the dura and bone or through tumor cell migration along the ventriculoperitoneal shunts. after the surgical procedure, the tumor cells may access the lymphatic or blood circulation through the damaged blood - brain barrier (bbb). craniotomy with tumor resection is associated with the opening of the brain vessels and can be associated with the spread of tumor cells, as previously demonstrated in the literature15). in the present case, the patient underwent several operations, which might increase the chance of distant metastasis. in the literature, the most common sites of metastases were pleura / lungs, followed by lymph nodes, bones and liver8,11,12). in the report on the extraneural metastases of astrocytoma and glioblastoma, the distribution of metastases was, as follows : 43 (59.7%) lung and pleural, 37 (51.4%) lymph node, 22 (30.5%) bone, 16 (22.2%) liver, 5 heart, 3 adrenal gland, 2 each in the kidneys, diaphragm and mediastinum, and 1 each in the pancreas, the thyroid gland, and the peritoneum11). for establishing the presence of extraneural metastasis, the following 4 criteria should be met16) : 1) the metastatic lesion must be histologically identified as cns tumor ; 2) the clinical history must indicate a cns tumor as the initial neoplasm ; 3) a complete autopsy must be performed to exclude the possibility of any other primary tumor ; 4) the morphologic features of the primary lesion and of the metastatic lesion must be identical. in this case, the patient fulfilled these criteria. at presentation with extraneural metastasis, this patient developed enlargement of the cervical lymph node. since the patient showed the lymphatic involvement of the gbm as extraneural metastasis, we considered that the main pathway of extraneural metastasis might be the lymphatic spread. the possibility of hematogenous metastasis to the neck should be included, because the patient had undergone multiple craniotomies. although it has been well known that surgery could be a risk factor for the extraneural metastasis of the gbm, surgery is not a prerequisite for the extraneural spread of the primary cns tumor. spontaneous metastases also have been reported in patients who had not experienced previous surgery6). spontaneous spreading of the tumor was attributed to direct invasion in both the vascular and the lymphatic systems. in summary, this patient survived for 6 years after aggressive treatments including surgery for 5 times, radiotherapy and chemotherapy. we suggest that the relatively longer lifespan of this patient might have affected the extraneural metastasis of the gbm. the damage of the cerebral vessels and of the bbb by repeated surgical manipulations could also accelerate the tumor penetration outside of the cns. although the exact mechanism of the extraneural metastasis is not well understood, the gbm can metastasize to extraneural organs. multiple craniotomies and longer survival period of the patient could be considered as risk factors of the extraneural metastasis. this present case provides proof for the possibility of extraneural metastasis of the gbm, especially in patients with longer survival. the neuro - oncologists should pay attention to the systematic survey for extraneural metastasis of the gbm. | glioblastoma multiforme (gbm) is the most aggressive intracranial tumor and it commonly spreads by direct extension and infiltration into the adjacent brain tissue and along the white matter tract. the metastatic spread of gbm outside of the central nervous system (cns) is rare. the possible mechanisms of extraneural metastasis of the gbm have been suggested. they include the lymphatic spread, the venous invasion and the direct invasion through dura and bone. we experienced a 46-year - old man who had extraneural metastasis of the gbm on his left neck. the patient was treated with surgery for 5 times, radiotherapy and chemotherapy. he had survived 6 years since first diagnosed. although the exact mechanism of the extraneural metastasis is not well understood, this present case shows the possibility of extraneural metastasis of the gbm, especially in patients with long survival. |
the acute respiratory distress syndrome (ards) remains a matter of high concern in critically ill - patients. mortality of the syndrome in the intensive care unit (icu) and in - hospital still fluctuates around 40%. treatment of ards involves adequate control of the underlying disease, mechanical ventilation with application of positive end - expiratory pressure (peep), judicious fluid management and organ support. however, the only intervention resulting in a mortality benefit has been the introduction of low - tidal volume (i.e., 5 - 7 ml / kg predicted body weight) ventilation. high - frequency ventilation (hfv) has been proposed as an alternative to conventional ventilation. among hfv techniques, high - frequency percussive ventilation (hfpv) has been shown to improve oxygenation and ventilation at a lower peak inspiratory pressure and with minimal effects on hemodynamics. an additional benefit of hfpv is its ability to enhance the recruitment and mobilization of secretions from the lung periphery to the central airways, thus potentially resolving atelectasis and preventing pneumonia. hfpv has shown promising results in neonatal and pediatric ards and in adult patients with inhalational lung injury. however, in adult ards patients, hfpv is either not recommended or only positioned as a salvage treatment for refractory hypoxemia in some centers. we report our experience with hfpv in an adult ards cohort, particularly regarding the effect of hfpv on respiratory parameters and outcome. in addition, we investigated whether hfpv produced different effects on oxygenation, ventilation and mortality in pneumonia - induced septic versus non - septic ards. the study was designed as a historical cohort study (retrospective analysis of prospectively gathered data) and included 59 ards patients who had been switched to hfpv within 24 h after initiation of conventional ventilation. the study was approved by the institutional review board and ethical committee of the university hospital brussels (file n b.u.n. berlin definition as respiratory failure not due to cardiac failure or fluid overload, occurring within 1 week after a well - defined clinical insult and characterized by bilateral opacities on chest x - ray not explained by effusions (partial) lung collapse or masses. moderate (100 mmhg 70%. an adequate cardiac output was assured at baseline under transesophageal echocardiographic guidance. to achieve resuscitation goals, patients received colloid and crystalloid infusion and if needed, dobutamine or norepinephrine. all patients received standard routine treatment and care for the disease processes underlying ards (i.e., antibiotics, fracture fixation, protocolized glucose control, enteral and/or parenteral nutrition, stress ulcer and deep vein thrombosis prophylaxis and respiratory physiotherapy). hfpv was initiated at the attending physician 's discretion and performed with the vdr-4 percussionnaire (volumetric diffusive respirator, bird technologies, sandpoint, i d). ventilator starting settings were : high - frequency rate 500/min ; pulsatile flow rate to attain a peak inspiratory pressure of maximum 30 cm h2o ; oscillatory peep 10 cm h2o ; fio2 100% ; ti / te = 1.5/1 ; i / e = 1/1 to 1/2. hfpv goals were : ph 7.35 - 7.45 ; paco2 35 - 45 mmhg and spo2 > 95%. adequate humidification was assured by a high - volume nebulizer incorporated in the ventilator circuit, an external heated humidifier (f and p 850 system ; fisher and paykel health - care, auckland, nz) and continuous instillation of 10 ml / h water directly into the endotracheal tube. blood gases were determined at least every 4 h or when considered as necessary by the attending physician. ventilation and oxygenation were adapted according to a predefined protocol [figure 1 ] under the supervision of a dedicated team of trained physicians and respiratory therapists. patients stable on hfpv could be switched at the physician 's discretion to conventional pressure - controlled ventilation and subsequently weaned. high - frequency percussive ventilation protocol spss for windows (ibm, spss, statistics for windows, version 20.0, ibm corp., fisher 's exact test and mann - whitney u test were performed to evaluate differences in age, gender, mortality and acute physiology and chronic health evaluation ii score between patients with pneumonia - related or -unrelated ards. respiratory variables and ph between these two ards groups were compared by one - way analysis of variance for repeated measurements followed by bonferroni correction for multiple comparisons. kaplan - meier survival analysis was performed including a log - rank (mantel - cox) test. patient 's selection procedure was depicted in figure 2. of the 42 evaluable patients, baseline demographics, severity of illness, lung injury score, respiratory variables and peep levels were comparable between both groups [table 1 ]. 22 (52%) of the patients had severe ards, including 10 (50%) pneumonia - associated cases and 12 (54%) non - septic subjects. barotrauma diagnosed prior to start high - frequency percussive ventilation patient characteristics at baseline and primary cause of ards the evolution of ph, paco2 and pao2/fio2 during hfpv was outlined in figure 3 (all patients) and figure 4 (pneumonia vs. non - septic patients). data collection and comparison between patient groups were relevant for up to 6 days of hfpv treatment. thereafter, the number of patients remaining on hfpv became too low to allow meaningful statistical evaluation. evolution of ph, paco2 and pao2/fio2 during high - frequency percussive ventilation treatment in all patients. p 7.35, paco2 35 - 45 mmhg and pao2/fio2 > 225). in patients with documented ards, hfpv provided comparable oxygenation and ventilation at a lower peak, mean and end - expiratory pressures as compared with conventional ventilation. however, this study does not match current standards of care since it compared the now obsolete intermittent mandatory ventilation mode with hfpv delivered by a non - commercialized vdr device. subsequent observational studies evaluating hfpv in critically ill - patients with ards mainly included surgical and trauma patients and used hfpv as a non - protocolized rescue therapy for intractable hypoxemia. in general, these studies confirmed significant improvement of oxygenation after 16 - 48 h of treatment. in head - injured patients, our study results suggested that patients whose ards was pneumonia - based may respond differently to hfpv than patients with non - septic ards. we observed a similar pattern of normalization and stabilization of ph and paco2 in both patient groups. however, significant improvement of oxygenation was observed in the non - septic ards group only. during hfpv, the latter also displayed better, though not significantly, oxygenation than pneumonia patients developing ards. non - septic patients had more hfpv - free days, suggesting better tolerance of this ventilation mode. this diverging response of pneumonia - related versus non - sepsis associated ards to hfpv remains unexplained. however, sepsis- and non - sepsis - related ards are thought to be different entities with regard to pathophysiology, clinical features and outcome. septic ards patients indeed present more acute inflammation and a higher degree of endothelial cell and coagulation activation than their non - septic counterparts. clinically, sepsis - related ards is linked to a higher mortality, a lower successful extubation rate and fewer ventilator - free and icu - free days. whole group overall 30-day and hospital mortality in our study were in - line or even lower than reported during conventional protective or prone position ventilation. yet, a more striking observation was the much higher 30-day and hospital mortality in pneumonia - related when compared with sepsis - naive ards. moreover, most deaths in the pneumonia group were related to refractory septic shock and multi - organ failure. thus, although highly speculative, it is conceivable that hfpv adversely propagated reactive pathways in pneumonia - related ards that promoted or enhanced local and/or remote inflammation and subsequent organ damage. our results can not be compared with the existing literature on hfpv use in ards since published data predominantly relate to trauma patients. nonetheless, the few described medical ards patients, most of whom suffering pneumonia, had an icu mortality approaching 65%. further research is needed to elucidate why hfpv offers no outcome benefit in pneumonia - related ards. first, despite being the largest observational study to date, our patient sample size is still much too low to allow any concrete positioning of hfpv in current management of adult ards. second, it is not known what the course and outcome of ards in our study population would have been if patients had been continued on protective conventional ventilation. this issue can only be solved by a large prospective randomized study comparing both types of ventilation within the constraints of a strict ventilation protocol. third, the retrospective nature of our study precluded to retrieve and to compare data regarding respiratory mechanics, airway pressures and hemodynamic variables, all of which being potentially relevant to ventilation and patient outcomes. finally, hfpv requires the use of a ventilator that is not available in all icus. though more user - friendly than its predecessors, the vdr-4 percussionaire remains difficult to handle. the success of hfpv remains directly proportional to the enthusiasm and commitment of respiratory therapist(s) and icu staff. insufficient knowledge of the ventilator, untimely adaptation of ventilatory settings, or non - adherence to an established ventilation protocol will all preclude obtaining adequate results and risk to turn hfpv into a frustrating experience. the application of hfpv in moderate and severe ards resulted in rapid and sustained improvement in oxygenation and ventilation. pneumonia - related ards patients submitted to hfpv have less improved oxygenation, longer ventilation dependency and worse survival than non - sepsis - related ards patients. whether this is due to a hfpv - induced triggering of injurious local and/or systemic inflammatory processes | background : few studies have investigated high - frequency percussive ventilation (hfpv) in adult patients with acute respiratory distress syndrome (ards).materials and methods : we retrospectively analyzed data from critically ill - patients with moderate and severe ards who received hfpv. ventilation and oxygenation were governed according to a predefined protocol. hfpv was continued until patients could be switched to conventional ventilation.results:a total of 42 patients (20 with pneumonia - related ards and 22 non - septic ards cases) were evaluable. baseline demographic characteristics, severity of illness, lung injury score ; ph and respiratory variables were comparable between pneumonia and non - sepsis - related ards. within 24 h, hfpv restored normal ph and paco2 and considerably improved oxygenation. oxygenation improved more in non - septic than in pneumonia - related ards. patients with pneumonia - induced ards also remained longer hfpv - dependent (7.0 vs. 4.9 days ; p < 0.05). mortality at 30 days was significantly higher in pneumonia - related than in non - sepsis - related ards (50% vs. 18% ; p = 0.01).conclusions : hfpv caused rapid and sustained improvement of oxygenation and ventilation in patients with moderate to severe ards. less improved oxygenation, longer ventilator dependency and worse survival were observed in pneumonia - related ards. |
pancreaticoduodenectomy is a technically difficult procedure, and the incidence of postsurgical complications is high. particularly, pancreaticojejunostomy leakage is a very serious complication, and it has been shown that the most prevalent cause of death after pancreaticoduodenectomy is pancreatic juice leakage due to the failure of pancreatico - enterostomy that may develop during reconstruction of the pancreatic duct. if a pancreatic fistula develops, this leads to pancreatic juice leakage into the abdominal cavity, and adjacent vascular walls or intestinal walls may be damaged because of the potent self digestion capacity of the pancreatic juice. consequently intraabdominal hemorrhage, abscess formation, sepsis and other fatal conditions develop, possibly leading to death.1 although the incidence of pancreatic anastomosis leakage has been reported to vary according to different investigators, it has been reported that after pancreaticoduodenectomy pancreatic anastomosis leakage occurs in approximately 5~40% cases.234 numerous risk factors for leakage of the pancreas tico - enterostomy area have been reported, such as the size of the pancreatic duct, the presence or absence of pancreatitis, insufficient blood supply to the anastomosis site, hemorrhage in the anastomosis site, the level of tension in the anastomosis site, the weak tissue of the pancreas, and the experience of surgeons have been reported.15678 for safe pancreatic anastomosis, diverse surgical techniques have been and studied that compared the outcomes of combination surgical methods such as pancreaticojejunostomy, pancreaticogastrostomy, duct - to - mucosa surgical methods, dunking surgical methods, or with or without stent installation. however, no significant differences in the development of pancreatic juice leak were observed, and until recently, a means that reduces the development of complications is as yet unavailable.9 mathur. have reported recently that the incidence of pancreaticojejunostomy leakage is increased in patients with infiltration of fat tissue into the pancreatic parenchyma in the vicinity of the anastomosis site.10 in 1933, ogilvie confirmed the infiltration of fat tissue in the pancreatic parenchyma by autopsy, and reported that it was detected in 9% of normal weight cases and 17% of obese cases.11 later, olsen has observed that as age and weight increased, the extent of fat tissue infiltration into the pancreatic parenchyma was more severe.12 also, several investigators have reported the correlation of fat infiltration within the pancreas to obesity.13 in addition, some investigators have reported studies suggesting the possibility of the increase in the incidence of pancreatic anastomotic leakage after pancreaticoduodenectomy in patients with infiltration of fat tissue within the pancreas.1014 therefore, in our study, by examining the infiltration of fat tissue in the pancreatic parenchyma of patients who received pancreatectomy, the association with clinical markers such as the patient obesity, the presence or absence of diabetes, etc. was investigated. in addition, it was examined whether infiltration of fat tissue correlates with development of pancreaticojejunostomy leakage after pancreaticoduodenectomy. from january 2007 to november 2008, 54 patients received pancreatectomy at our institution. among them 35 patients were male (64.8%), 19 were female (35.2%), and the mean age was 58.511.1 years (range ; 22~73 years). with regard to surgical method, pancreaticoduodenectomy was performed in 37 patients, distal pancreatectomy in 17 patients, and the mean body mass index (bmi) was 22.82.9 kg / m. the range of the bmi was from a minimum 16.3 kg / m to a maximum 30.9 kg / m. there were 35 normal group patients whose bmi was lower than 24 kg / m was, and 16 were obese patients with higher than 24 kg / m bmi. the type of disease consisted of pancreatic cancer in 12 patients, benign pancreatic tumor in 15 patients, biliary tract cancer in 13 patients, ampulla of vater cancer in 5 patients, gastric cancer in 3 patients, duodenal cancer in 2 patients, and other diseases in 4 patients (table 1). in particular, the incidence of complications after pancreaticoduodenectomy or pylorus - preserving pancreaticoduodenectomy (pppd) was compared with end - to - side duct - to - mucosa pancreaticojejunostomy as the standard procedure. suture methods were interrupted sutures, and pancreatic stent insertion was performed. for the assessment of pancreatic juice leakage and drainage, patient progress was assessed by performing serum tests on the days 1, 3 and 7 after surgery, and the presence or absence of pancreatic juice leakage was determined by measuring the amylase and lipase levels in the body fluid drained by the draining tube. by assessing the presence or absence of the development of pancreaticojejunostomy leakage after pancreaticoduodenectomy and pylorus - preserving pancreaticoduodenectomy, as well as on the day of the removal of the draining tube, the correlation with the infiltration of fat tissue in the pancreatic parenchyma was analyzed. by histological examination of pancreatic tissues extracted from 54 patients who received surgery the presence of fatty tissue in the pancreatic parenchyma was assessed, and the patients were assigned to the non - fat group and the fat group. the correlation of the presence or absence of fatty tissues in the pancreatic parenchyma to clinical markers was analyzed. in addition, in patients who received pancreaticoduodenectomy, the incidence of complications according to the presence or absence of fatty tissue was compared. as the objective standard, pancreatic leakage was defined as a concentration of amylase obtained from the drainage that was more than three times higher than normal serum values, and more than 50 ml / day drainage after the 11 post - operative day15 in addition, to compare the level of leakage, the standard of bassi. in 32 among the total of 54 patients, fat tissue was detected in the pancreatic tissue of patients (59.3%). with regard to distribution of fat tissue the gender and mean age of the non - fat group were similar to the fat group (non - fat group, 56.913.3 years vs. fat group 59.69.4 years, p=0.133). similarly, there was no statistically significant difference in terms of the presence or absence of adipose tissues in the pancreas, as well as with or without the association with (non - fat group, 3/22 vs. fat group 2/32, p=0.304). in the obese patients whose pre - operative bmi was greater than 24, the presence of fat tissue in the pancreatic parenchyma was statistically higher (non - fat group, 3/22 vs. fat group 13/32, p=0.027). a trend of a higher pre - operative serum cholesterol level was observed in the fat group (non - fat group, 148.342.9 vs. fat group, 172.449.4, p=0.069), but no statistical difference (table 3). among the total of 54 patients, postsurgical pancreaticojejunostomy leakage developed in 9 patients (21.05%). in patients with leakage, severity isgpf grade16 a occurred in 3 patients, grade b in 1 patient, and grade c in 5 patients. clinically, grade b and c patients were classified as major leakages. in patients who received pancreaticoduodenectomy, the incidence of the complications of the pancreaticojejunostomy site according to the presence or absence of fat tissue in the resection margin was compared, and showed that 31.8% (7/22) had fat tissue, while 13.3% (2/15) did not, showing no statistical difference (p=0.186). the rate of major leakage in the non - fat group was 18.2% (4/22), and 13.3% (2/15) in the fat group, again demonstrating no statistical difference (p=0.532) (tables 4, 5). in 32 among the total of 54 patients, fat tissue was detected in the pancreatic tissue of patients (59.3%). with regard to distribution of fat tissue the gender and mean age of the non - fat group were similar to the fat group (non - fat group, 56.913.3 years vs. fat group 59.69.4 years, p=0.133). similarly, there was no statistically significant difference in terms of the presence or absence of adipose tissues in the pancreas, as well as with or without the association with (non - fat group, 3/22 vs. fat group 2/32, p=0.304). in the obese patients whose pre - operative bmi was greater than 24, the presence of fat tissue in the pancreatic parenchyma was statistically higher (non - fat group, 3/22 vs. fat group 13/32, p=0.027). a trend of a higher pre - operative serum cholesterol level was observed in the fat group (non - fat group, 148.342.9 vs. fat group, 172.449.4, p=0.069), but no statistical difference (table 3). postsurgical pancreaticojejunostomy leakage developed in 9 patients (21.05%). in patients with leakage, severity isgpf grade16 a occurred in 3 patients, grade b in 1 patient, and grade c in 5 patients. clinically, grade b and c patients were classified as major leakages. in patients who received pancreaticoduodenectomy, the incidence of the complications of the pancreaticojejunostomy site according to the presence or absence of fat tissue in the resection margin was compared, and showed that 31.8% (7/22) had fat tissue, while 13.3% (2/15) did not, showing no statistical difference (p=0.186). the rate of major leakage in the non - fat group was 18.2% (4/22), and 13.3% (2/15) in the fat group, again demonstrating no statistical difference (p=0.532) (tables 4, 5). presently in korea, reports on the infiltration of fat tissue into the pancreatic parenchyma of surgical tissues and its clinical significance are few. gaujoux.14 have reported in a study which was conducted on 100 patients who received pancreaticoduodenostomy that in patients with infiltration of fat tissue into the pancreas, patients without fibrosis findings in the pancreas, and patients with a body mass index higher than 25 kg / m, the incidence of complications was increased. the result of our study showed that in obese patients whose pre - operative bmi was higher than 24, the probability of the presence of fat tissue in the pancreatic parenchyma was statistically high. the incidence of pancreaticojejunostomy leakage according to the presence or absence of fat tissue was not statistically different. in our study, tissues were collected from the dissection surface of the resected pancreas, as well as from random sites, prepared as slides, and examined under light microscopy, and thus the possibility of the presence of fat tissue in unexamined areas can not be ruled out. therefore, to assess the presence or absence of fat tissue, it may be necessary to establish a regular standard method for tissue collection. however, since it is considered that fat tissue on the resection surface are involved in the association with surgical complications, the authors of this study regard the method of our study to be valid. in the present study, the development of pancreatic duct leakage that manifested after pancreaticoduodenectomy was not statistically associated with the presence of fat tissue on the resection surface of pancreas. lee.17 have pointed out that the increase of fat found during magnetic resonance imaging, which was performed for predicting the development of pancreatic fistulas in the pancreas, was a risk factor for post - operative pancreatic fistula formation. this report was based on radiological examination and did not confirm the resected samples of actual tissues, and thus it was different from our study. in our patient groups, fat tissue was detected in the pancreatic parenchyma in 59.3% of the total patients. a higher detection trend was observed among the female patients, and in patients with a body mass index greater than 24 kg / m was shown. this infers that in obese patients, the possibility of the presence of fat tissue in the pancreatic parenchyma is high. however, in our subject patients, highly obese patients whose bmi was greater than 35 were not included, and thus additional studies on such a cohort may be required. in addition, the development of complications after pancreaticoduodenectomy as well as the association with accompanying diabetes was not be observed, which may be due to the small number of subject patients. therefore, it is thought that studies on a larger number of patients are recommended. | purposein korea, there are few reports regarding the infiltration of fat tissue in pancreatic parenchyma in surgically resected organs. it is necessary to ascertain the correlation between the presence of fat tissue in the resection margin of the pancreas and the surgery outcome.methodsfifty four patients who underwent pancreatic resection from jan. 2007 to nov. 2008 were enrolled in this study. pathologic examination was performed to determine the presence of fat tissue in resected pancreatic parenchyma. statistical correlation between the presence of fat tissue with clinical parameters and postoperative complication rates was analyzed.resultsamong the specimens of all fifty four patients, fat tissue was found in 32 specimens of patients (59.3%). female gender and patients whose body mass index exceeded 24 kg / m2 were statistically correlated with the presence of the fat tissue in pancreatic parenchyma. there was no statistical relationship between infiltration of fat tissue with postoperative complications.conclusionthis study may serve as the base data for study in radiological imaging in detecting pancreatic tissue. a further larger scaled study is needed to validate the result of this study. |
tuberculosis is one of the leading infectious causes of death in the world. according to the who estimates some patients with tuberculosis may also have other coexisting diseases like hiv, diabetes, osteoarthritis, hypertension which will also require drug therapy for a sustained period. the standard treatment for tuberculosis is a combination of rifampicin, isoniazid, pyrazinamide and ethambutol. since antituberculosis drug therapy (att) is given for a minimum period of six months, patients having other coexisting diseases will be taking other additional drugs along with att. it has been described to be a pleiotropic inducer as several enzymes are induced by it, some of them being cyp1a, cyp2a, cyp2c, cyp2d6, cyp2e1 and cyp11b1. enzyme induction leads to the production of more enzymes, usually after three or more days of drug treatment. increased enzyme levels will lead to increased metabolic activity and to a quicker degradation of drugs used for the other diseases. a classic example of the above situation is the combination of oral contraceptives (ocp) with att where rifampicin leads to ocp failure. isoniazid is known to inhibit cyp1a2, cyp2a6, cyp2c9, cyp2c19, cyp2e1 and cyp3a4. so when drugs metabolized by the above enzymes are given to a patient on att, there is a risk of drug toxicity due to impaired metabolism. however when an inducer and an inhibitor is given together for a patient with tuberculosis the net effect on the drug metabolizing enzyme has not been widely studied at therapeutic doses in vivo. so the combined effect of att on one of the drug metabolizing enzyme cyp2c9 is attempted. cyp2c9 is one of the major drug metabolizing enzymes known to metabolize many of the drugs such as nsaids, sulfonylureas, oral anticoagulants, diuretics, angiotensin ii blockers, phenytoin, cyclophosphamide, fluoxetine, etc. the gene coding for this enzyme cyp2c9 is mapped on chromosome 10 between q23 and q24. two inherited amino acid substitutions in cyp2c9 namely, arg144cys (2 allele) and ile359leu (3 allele) are known to affect catalytic function of the enzyme cyp2c9. the genotype frequency of cyp2c9 in tamil nadu population done in an earlier study was cyp2c9 1/1 82%, cyp2c9 1/2 4% and cyp2c9 1/3 12%. so the aim of the study was to find the effect of anti - tuberculosis therapy on polymorphic drug metabolizing enzyme cyp2c9. the study was conducted at the tuberculosis clinic of the department of pulmonary medicine, jawaharlal institute of postgraduate medical education and research [jipmer ], pondicherry. the study was approved by the institutional ethics committee. after explaining the study procedure, informed consent was obtained from each participant the patients were diagnosed based on the sputum smear acid fast bacteria (afb) positivity or a histopathological examination of the specimen showing features suggestive of tuberculosis or a pleural fluid adenosine deaminase titers > 60. unrelated newly diagnosed patients with pulmonary and extra - pulmonary tuberculosis, of either sex or age above 18 years residing in tamil nadu and pondicherry for more than three generations and speaking tamil as mother tongue were included in the study. all patients with coexisting severe illnesses which warrant hospitalization, pregnant women and patients taking any other medications which induce or inhibit cyp2c9 were excluded from the study. after explaining the procedure and taking a written informed consent from the tb patients, they were administered tab phenytoin 300 mg in an empty stomach, as a probe drug for cyp2c9. the patients were asked to return after one month of anti - tuberculosis therapy as prescribed by the chest physicians (rifampicin 10 mg / kg/, isoniazid 5 mg / kg, pyrazinamide 25 mg / kg and ethambutol 15 mg / kg per day). the phenotyping procedure was repeated again after one month of att to look for the change in the cyp2c9 enzyme activity. after centrifugation of the sample, the cellular part (leucocytes) was used for dna extraction by phenol chloroform method and the cyp2c9 genotyping by pcr - rflp method. the remnant plasma was used for estimation of phenytoin and its metabolite p - hpph (para hydroxyl phenyl hydantoin) by reverse phase high performance liquid chromatography according to the method described earlier. pure powders of phenytoin and the metabolite 5-(para - hydroxyphenylhydantoin (p - hpph) were procured from aldrich chem co. wisconsin, usa. all data are presented as mean sem. the data are analysed using graphpad instat statistical software (graphpad software inc, san diego, ca, usa) version 5.02. the mean values of phenytoin, p - hpph and phenytoin metabolic ratio were tested for deviation from the normality using kolmogorov - smirnov test. the concentration of phenytoin and metabolic ratio were compared before and after att using paired t test. the concentration of phenytoin and metabolic ratio were compared between the different cyp2c9 genotype groups using kruskal wallis test. the data are analysed using graphpad instat statistical software (graphpad software inc, san diego, ca, usa) version 5.02. the mean values of phenytoin, p - hpph and phenytoin metabolic ratio were tested for deviation from the normality using kolmogorov - smirnov test. the concentration of phenytoin and metabolic ratio were compared before and after att using paired t test. the concentration of phenytoin and metabolic ratio were compared between the different cyp2c9 genotype groups using kruskal wallis test. the data are analysed using graphpad instat statistical software (graphpad software inc, san diego, ca, usa) version 5.02. the mean values of phenytoin, p - hpph and phenytoin metabolic ratio were tested for deviation from the normality using kolmogorov - smirnov test. the concentration of phenytoin and metabolic ratio were compared before and after att using paired t test. the concentration of phenytoin and metabolic ratio were compared between the different cyp2c9 genotype groups using kruskal wallis test. there was no significant difference in the demographic parameters observed among the cyp2c9 genotype groups. in the cyp2c9 1 1 genotype, the mean plasma concentrations of phenytoin before and after one month of att were 5.2 0.3 g / ml and 3.5 0.4 g / ml respectively, a reduction by 33% showing significant induction. the range of phenytoin concentration was 3.27 7.07 g / ml. this difference in phenytoin concentration showed significant change only in the wild type population of cyp2c9 but was absent in the hetero mutant population [table 2 ]. the mean concentration of phenytoin after one month of anti - tuberculosis treatment was 3.5 g / ml and the range was 0.2 - 8.1 g / ml. the metabolic ratio was also observed to reduce significantly (p < 0.05) when the cyp2c9 1 2, cyp2c9 1 3, and cyp2c9 3 3 data were pooled together.. demographic parameters of the study patients change in phenytoin concentration and metabolic ratio before and after 1 month of att in different cyp2c9 genotypes the most common adverse effects with att observed was dizziness (9.2%), the others being myalgia, pruritus, nausea, vomiting, dyspepsia, headache, macular rash, diplopia and alopecia. these adverse reactions occurred mainly during the first two weeks of therapy with att and subsided spontaneously. to the best of our knowledge, this is the first human study to examine the relationship between impact of genotype and induction / inhibition potential in tuberculosis patients. phenytoin was used as a probe drug to evaluate the activity of cyp2c9 enzyme, since it is metabolised predominantly by this enzyme and its use as a probe drug for cyp2c9 enzyme had earlier been validated in an earlier publication using the ratio of phenytoin and its metabolite concentration. it would have been more informative to study the effect of att on multiple enzymes simultaneously but considering the fact that giving a cocktail of probe drugs would make it cumbersome to a patient already receiving multiple drugs as part of his treatment, we restricted ourselves to studying cyp2c9. we chose to limit the study period to 30 days mainly for logistic reasons because after 30 days patients would anyway have to visit the hospital to receive the att drugs for the follow up. after the second month of treatment most patients were referred to the local primary health centres to receive the drugs by dots therapy. so it would be difficult to expect patients to visit the hospital solely for the study purpose after 120 days. additionally, the induction and inhibition potential of att can be reasonably gauged with one month of att. the mean plasma concentration of phenytoin observed after 3 hours of oral intake of a single dose of phenytoin (300 mg) was 5.1 g / ml. there was no significant difference in the plasma concentration of phenytoin or its metabolite between different cyp2c9 genotype groups at baseline. this finding was similar to that observed in a study that was done on healthy volunteers in tamilian population done in our lab. in epileptic patients with polymorphic cyp2c9 enzyme such as cyp2c9 1 3 it has been observed that the phenytoin requirement is considerably reduced due to the diminished enzyme activity and the dose requirement was still lower in the homomutant population. such variation is not observed here probably because the cyp2c9 enzyme has still not reached saturation kinetics as it is a single dose study. the mean concentration of phenytoin after one month of anti - tuberculosis treatment was 3.5 g / ml and the range was 0.2 - 8.1 g / ml. the significant decrease (33%) in the phenytoin concentration after one month of anti - tuberculosis treatment implies that there is an enhancement of the metabolism of the probe drug phenytoin by the enzyme cyp2c9. the metabolic ratio (dph / p - hpph) has also shown a significant decrease after one month of att. all these results are in conformity with previous studies that showed that rifampicin is a strong pleiotropic inducer of drug metabolizing enzymes including cyp2c9 (2). several clinical studies have shown that rifampicin increases the clearance of co - administered drugs such as fluconazole, pioglitazone, oral contraceptives, gliclazide, sulfasalazine, atazanavir, saquinavir, etc. although rifabutin is known to have a lesser induction potential as compared to rifampicin, a literature search did not show any study highlighting the genotype impact on the induction and inhibition potential of rifabutin. although isoniazid is a weak inhibitor of cyp2c9 enzyme, when it is given in combination with rifampicin, ethambutol and pyrazinamide for 30 days, the net effect that has been observed in this study this is in conformity to an earlier study done in tuberculosis patients which showed that the inducing effect of rifampicin is much more pronounced than the inhibitory effects of isoniazid when both the drugs are given in combination. however it has also been observed that isoniazid can cause phenytoin toxicity when both the drugs are administered together due to the predominant inhibitory effect of isoniazid. the average decrease in phenytoin concentration and the decrease in metabolic ratio after one month of att was observed in both the groups. this indicates that anti - tuberculosis treatment has produced a significant induction in the mutant groups. despite the low amount of enzyme levels present in patients of heterozygous and homozygous variant genotype, induction of enzymes this would mean that the genotype of the individual does not play a major role in determining the degree of induction of cyp2c9. these findings are similar to a study done in healthy volunteers who were given rifampicin 450 mg for four days to see if it could change the kinetics of the probe drug tolbutamide. this is in contrast to an earlier study using mephenytoin as a probe drug, which showed that induction of the cyp enzymes by rifampicin was only observed in extensive metabolisers but not in poor metabolisers. we however could not find any reason for the sixteen fold increase in induction that was observed in the patient with cyp2c9 3 3. in addition to the polymorphisms of p450 genes, genetic variations of nuclear receptors and regulatory proteins that modulate the transcriptional processes of p450 expression, intracellular and tissue concentration of inducers, physiological factors such as hormones, development and disease and other environmental elements could play a significant role in the variability of p450 expression. in this study, all patients were given the anti - tuberculosis drugs based on their body weight. thus even individual differences in the intracellular concentration of inducers such as rifampicin could cause differences in the degree of induction. the intracellular concentration of the inducers can be influenced by a variety of drug transporters such as p- glycoprotein which can cause efflux of the drug. it has been observed that in mdr1 overexpressed human colon carcinoma cells, the induction of cyp3a4 by rifampicin was reduced when compared to the parental cells. oral treatment with rifampicin in increasing doses was also shown to result in elevated drug levels in the livers of mdr1a (-/-) when compared to of mdr1a (+ /+) mice. the human liver - specific organic anion - transporting polypeptide c (oatp - c) mediates the hepatocellular uptake of rifampicin. variation of oatp can also reduce the intake of rifampicin and thereby weaken rifampicin mediated pregnane x receptor activation. there are no published data on the frequencies of oatp - c polymorphisms in indian population. interleukin - 6 decreases both rifampicin and phenobarbital mediated induction of cyp2b6, cyp2c8, cyp2c9 and cyp3a4. mycobacterium tuberculosis has shown to activate interleukin 6 and thereby decrease the induction of cyp2c9. if there is a variation in interleukin 6 activation it can also partly explain the variability in enzyme induction. the lack of adequate sample size in the homozygous and heterozygous population of individuals with cyp2c9 polymorphisms has made it difficult to give conclusive evidence on the influence of genetic polymorphisms on enzyme induction. nevertheless considering the fact that the frequency of the cyp2c9 variants is reduced in the general population, it is not surprising to find a lower sample size in this study among tb patients. the results of this study may offer sufficient ground for elucidating further, the interaction of genotype and the induction inhibition potential of att therapy. the dose of phenytoin that was given to the patients was a fixed dose and not one based on the individual patient 's body weight. however the induction was detected appreciably in both the heterozygous population of cyp2c9 1 2 and cyp2c9 1 3 thereby showing that the genotype of the individual may not significantly influence the degree of induction. the role of other genetic factors such as mutation in promoter region of oatp and mdr1 polymorphisms in induction needs to be studied to have a better understanding on the influence of genotype on induction of the cyp2c9 enzyme. the lack of adequate sample size in the homozygous and heterozygous population of individuals with cyp2c9 polymorphisms has made it difficult to give conclusive evidence on the influence of genetic polymorphisms on enzyme induction. nevertheless considering the fact that the frequency of the cyp2c9 variants is reduced in the general population, it is not surprising to find a lower sample size in this study among tb patients. the results of this study may offer sufficient ground for elucidating further, the interaction of genotype and the induction inhibition potential of att therapy. the dose of phenytoin that was given to the patients was a fixed dose and not one based on the individual patient 's body weight. however the induction was detected appreciably in both the heterozygous population of cyp2c9 1 2 and cyp2c9 1 3 thereby showing that the genotype of the individual may not significantly influence the degree of induction. the role of other genetic factors such as mutation in promoter region of oatp and mdr1 polymorphisms in induction needs to be studied to have a better understanding on the influence of genotype on induction of the cyp2c9 enzyme. the lack of adequate sample size in the homozygous and heterozygous population of individuals with cyp2c9 polymorphisms has made it difficult to give conclusive evidence on the influence of genetic polymorphisms on enzyme induction. nevertheless considering the fact that the frequency of the cyp2c9 variants is reduced in the general population, it is not surprising to find a lower sample size in this study among tb patients. the results of this study may offer sufficient ground for elucidating further, the interaction of genotype and the induction inhibition potential of att therapy. the dose of phenytoin that was given to the patients was a fixed dose and not one based on the individual patient 's body weight. however the induction was detected appreciably in both the heterozygous population of cyp2c9 1 2 and cyp2c9 1 3 thereby showing that the genotype of the individual may not significantly influence the degree of induction. the role of other genetic factors such as mutation in promoter region of oatp and mdr1 polymorphisms in induction needs to be studied to have a better understanding on the influence of genotype on induction of the cyp2c9 enzyme. our study has shown that one month of anti - tuberculosis treatment can cause a significant decrease in the metabolic ratio of phenytoin implying increased induction of cyp2c9.the concentration of phenytoin after one month of anti - tuberculosis therapy was also shown to reduce significantly which could be due to the induction of cyp2c9. however the induction of cyp2c9 was also found to be significant in individuals with deficient enzyme activity when pooled together as in cyp2c9 1 2 and cyp2c9 1 3 thereby showing that the cyp2c9 genotype of the individual may not influence the degree of induction caused by att. | objectives : patients on anti - tuberculosis therapy (att) are more prone to drug interactions in the presence of coexisting illnesses which warrant drug therapy. rifampicin is a strong cyp enzyme inducer while isoniazid is a potent cyp inhibitor. the objective of the study was to find the net effect of one month att on cyp2c9 enzyme and to correlate it with respect to the cyp2c9 genetic polymorphisms.materials and methods : forty eight newly diagnosed tuberculosis patients were included in the study based on the inclusion - exclusion criteria. before commencing att, they were given a single dose of phenytoin 300 mg as a probe drug for cyp2c9. blood sample was collected after three hours to carry out cyp2c9 genotyping by pcr - rflp method. phenotyping for cyp2c9 enzyme was done by measuring the ratio of phenytoin and its metabolite p - hpph (para hydroxy phenyl hydantoin) by reverse phase hplc (high performance liquid chromatography) method before and after one month of att.results:in the cyp2c9 1 1 genotype, the mean plasma concentrations of phenytoin before and after one month of att were 5.2 0.3 g / ml and 3.5 0.4 g / ml respectively, a reduction by 33% showing significant induction (p < 0.001). there was also significant decrease in the metabolic ratio after one month of att from 23.2 4.8 to 10.1 1.9 (p < 0.001). the metabolic ratio was also observed to reduce significantly (p < 0.05) when the cyp2c9 1 2, cyp2c9 1 3, and cyp2c9 3 3 data were pooled together.conclusion:the presence of polymorphisms in the cyp2c9 gene does not affect the induction potential of att. |
nitric oxide (no) is a highly reactive molecule with a range of physiological functions [1, 2 ]. this messenger plays an important role in the modulation of vascular tone, neurotransmission [4, 5 ], and immune system [68 ]. in addition to the constitutive forms of the enzyme (endothelial (enos or nos3) and neuronal (nnos or nos1)), there is also an inducible form (inos or nos2). this last is most commonly associated with inflammatory conditions in which no is produced in large amounts. there is strong evidence to suggest the involvement of inos in the development of neurodegenerative disease. induction of inos, no, and no byproducts has been found in multiple sclerosis (ms) patients and animal models and correlates with disease severity and level of inflammatory infiltrate [912 ]. interestingly, however, inos - deficient mice developed a more severe ms model [13, 14 ]. it was found that the elimination of inos does not improve, and may actually aggravate, demyelination in the cuprizone - demyelinating model, which suggests that the inos / no system may be neuroprotective. more information is required to understand the role of inos / no in inflammatory response, oligodendrocyte cell death, and myelin damage / loss. the cyclic guanosine 3,5-monophosphate (cgmp) signaling pathway is an important no - signaling molecule. no binds to soluble guanylyl cyclase (sgc) and increases concentration of cgmp, activating signaling cascades and leading to cgmp - dependent responses [16, 17 ]. the cgmp signal can be terminated by the action of several phosphodiesterases (pde). the cgmp - selective pde5 is expressed in the cardiovascular, neural, and immune systems. studies have shown that selective pde5 inhibitors, widely used in the treatment of erectile dysfunction in humans, such as sildenafil (viagra ; pfizer) and vardenafil (levitra ; bayer), raise cgmp levels in the brain and offer protective effects, improve cognition and memory, reduce neuronal cell death following ischemic cerebrovascular injury, decrease white matter damage, and regulate inflammatory responses in ms models [21, 22 ]. recent studies by the authors of an ms model induced in wild - type c57bl6 mice found that sildenafil has an anti - inflammatory action, reducing levels of proinflammatory cytokines and cyclooxygenase-2 (cox-2) and protecting the myelin structure. however, the mechanism of sildenafil neuroprotection remains unknown. in the present study, inflammatory demyelination was induced in inos mice, and sildenafil was administered for four weeks. the focus of this study was to identify the role of a potent inflammation - associated molecule, inos - derived no, in protective mechanisms related to sildenafil. the present study also aimed to clarify the role of no protective and/or deleterious mechanisms in the demyelinating model. five inos knockout (b 6.129 p2- nos2) mice, aged 7 to 10 weeks, weighing 15 to 20 g, were used per group. the mice were examined for health status, acclimated to the laboratory environment at 25c and 12 h light / dark photoperiod, and housed in metal cages. the control group received standard laboratory diet and pure water. over a four - week period, the experimental groups received either 0.2% cuprizone (oxalic - bis - cyclohexylidenehydrazide sigma - aldrich inc., st. louis, mo, usa) mixed into the chow and pure water or 0.2% cuprizone in the chow and 25 mg / kg of body weight of sildenafil (viagra ; pfizer inc., new york, ny, usa) administered through the drinking water [2224 ]. body weight was accessed every week and the drug concentration in the water was adjusted to maintain the dose. all experiments were carried out in compliance with ethical guidelines for animal experimentation (l-10/2010-ceua ; 05/10-cibio fiocruz). after treatment, the animals were anaesthetized (i.m.) with ketamine (115 mg / kg) and xylazine (10 mg / kg) (sespo comrcio e indstria ltda., the animals were transcardially perfused with physiological saline (20 ml), followed by 4% paraformaldehyde (sigma - aldrich) (40 ml) in 0.1 m phosphate (sodium phosphate monobasic and dibasic heptahydrate, sigma - aldrich) buffered saline (pbs), ph 7.2. cerebella were dissected and immersed in 15% sucrose overnight, followed by 30% sucrose for a second night (36 hours total). the specimens were then embedded in oct - tissue tek compound (sakura finetek, torrance, ca, usa) and frozen in n - hexane (dinmica, so paulo, sp, brazil) cooled with liquid nitrogen. cryosections (8 m thick) were permeabilized (0.3% triton x-100) and incubated for 1 h with blocking solution (3% bsa plus 0.2% tween 20 in tris buffered saline). subsequently, the sections were incubated with antibodies for glial fibrillar acidic protein (gfap) (dakocytomation, cat. sections were incubated with primary antibodies overnight and then incubated with polyclonal cy3-conjugated secondary antibodies (jackson, cat. no. 705 - 165 - 147) against rabbit immunoglobulin (1 : 200) for 1 h. the slides were washed and mounted in fluorescent prolong gold antifade medium (life technologies, cat. p36930) for observation under an inverted fluorescence microscope (zeiss microimaging gmbh) equipped with a camera (zeiss axiocam mrm) and the release 4.7.2 image analysis software. after perfusion as described for if, cerebella were immediately removed and postfixed in the same fixative overnight. the samples were dehydrated in an ethanol series (isofar chemical co., rj, brazil), cleared in xylene, and embedded in paraffin (merck, catalog no. sections (5 m thick) were cut on an rm 2035 microtome (reichert s, leica), rehydrated, washed in 0.05 m pbs, and incubated in this buffer with 1% bovine serum albumin (bsa, fraction v) (miles, naperville, il, usa) for one hour. endogenous peroxidase was blocked and antigen retrieval was performed, pretreating the sections with 20 mm citrate buffer, ph 6.0, at 100c, for 30 min. all groups were incubated with the rabbit polyclonal anti - cox-2 (abcam, canada / us, cat. ab15191) (1 : 100, overnight at 4c). after washing, the sections were overlaid for 1 h with a biotin - conjugated secondary antibody using an hrp kit (dakocytomation, ca, usa, biotinylated link universal hrp ; cat. the sections were then weakly counterstained with harris ' hematoxylin and mounted in entellan (merck, cat. cerebella were quickly dissected, and each group was homogenized in an extraction cocktail (10 mm edta, amresco, solon, usa ; 2 mm phenylmethane sulfonyl - fluoride, 100 mm naf, 10 mm sodium pyrophosphate, 10 mm navo4, 10 g of aprotinin / ml, and 100 mm tris, ph 7.4). cerebella of five animals were mixed and homogenized to form a pool from each group. briefly, the proteins (40 g total) were separated on 6.5% (ifn-), 10% (tnf-, il-1), or 12% (gfap, enos) acrylamide gel. after overnight in 5% nonfat milk, the primary antibodies against gfap (1 : 10,000, dakocytomation, cat. zo 334), cox-2 (1 : 1000, abcam, cat. no. ab15191), tnf- (1 : 1000, peprotech, nj, usa, cat. 500p119), il-1 (1 : 2500, genway biotech, inc., ca / usa, cat. no. 18 - 732 - 292194), gst3/gstpi (1 : 250, abcam, canada, cat. ab53943), and enos (1 : 1000, bd biosciences, cat. 610299) were incubated for four hours followed by horseradish peroxidase - conjugated antibodies anti - rabbit (1 : 80,000, sigma - aldrich, cat. a9169), anti - mouse (1 : 1,000, sigma - aldrich, cat. a0168), or anti - goat secondary antibody (1 : 100,000, sigma - aldrich, cat., the pixel density of each band was determined using the image j 1.38 software (http://rsbweb.nih.gov/ij/download.html ; developed by wayne rasband, nih, bethesda, md, usa). for each protein investigated, the results were confirmed in three sets of experiments. immunoblotting for -actin (1 : 1,000, sigma - aldrich, cat. after perfusion as described for if, the samples were dehydrated in a graded ethanol series, cleared in xylene, and embedded in paraffin. sections (5 m thick) were cut on an rm 2035 microtome (reichert s, leica). myelin was detected using luxol - fast blue (lfb) staining (solvent blue 38 ; sigma - aldrich) in accord with nunes.. the sections were observed under an inverted microscope (zeiss microimaging gmbh) equipped with a camera (zeiss axiocam mrm) and release 4.7.2 image analysis software (zeiss). after anesthesia, the animals were sacrificed by transcardial perfusion with physiological saline (20 ml), followed by 40 ml of fixative2.5% glutaraldehyde and 4% paraformaldehyde in 0.1 m sodium cacodylate acid (sigma - aldrich) buffer, ph 7.2. next, cerebellum fragments were washed twice in the same buffer and postfixed in a solution containing 1% osmium tetroxide (sigma - aldrich), 2 mm calcium chloride, and 0.8% potassium ferricyanide (sigma - aldrich) in 0.1 m cacodylate buffer, ph 7.2, dehydrated in acetone and embedded in spin - pon resin (embed 812-electron microscopy science, washington, pa, usa). resin polymerization was performed at 60c for 3 days. semithin sections (0.5 m in thickness) were placed on glass slides, stained with toluidine blue. ultrathin sections (70 nm in thickness) were placed on 300-mesh nickel grids, counterstained with 5% uranyl acetate (electron microscopy science) and lead citrate (sigma - aldrich), and examined using a fei morgagni 268d transmission electron microscope. the densitometric values of the immunoreactive bands (immunoblotting) were analyzed using the graphpad prism software package (san diego, ca, usa). one - way analysis of variance (anova), followed by dunnett 's and/or tukey 's posttest, was used to compare groups. clinical analysis revealed that cuprizone - treated animals suffered from motor limitations, such as tremors, and abnormal walking and posture. the group treated with sildenafil (25 mg / kg) exhibited normal walking and posture, and tremors were either mild or nonexistent. the inos control animals exhibited normal motor function and posture and explored their environment normally. the mice treated with cuprizone exhibited arched (shortened) posture and tremors and had difficulty in exploring the environment. mice treated with 25 mg / kg of sildenafil both walked and were able to explore the environment normally, with no or mild tremors, and were classified as score 1. cuprizone increased gfap, tnf-, and cox-2 expression in cerebellum, indicating astrocyte activation (reactive gliosis) and neuroinflammation. sildenafil treatment did not reduce the levels of these proteins in mice without inos. western blotting (wb) analysis showed that gfap, a marker of astrocyte activation (reactive gliosis), was present in the cerebellum of untreated inos animals (control) (figure 1(a)). treatment with 0.2% cuprizone for four weeks significantly increased expression of this protein (figures 1(a) and 1(c) ; p < 0.001). animals that concomitantly received sildenafil (25 mg / kg) and cuprizone also exhibited a high level of gfap in comparison to control (figures 1(a) and 1(c) ; p < 0.001). immunofluorescence (if) analysis of gfap in the cerebellum revealed the expression and location of this cytoskeletal intermediate filament protein in the animals. in the molecular layer of the cerebellum, gfap labeling revealed long astrocytic processes with a typical arrangement that was perpendicular to the pia mater membrane (bergmann glia) (figure 2(e)). astrocytic processes were also seen around other cells and vessels (arrowheads in figures 2(b), 2(d), and 2(e)). the control group showed basal expression of gfap localized normally (figures 2(a) and 2(d)). treatment with cpz induced astrogliosis, increasing the intensity of labeling in the astrocytes (figures 2(b) and 2(e)). in the sildenafil group, gfap labeling was more intense than for control (figures 2(c) and 2(f)). the inos control group had a basal level of tnf- (figure 3(a)). wb analysis showed that cuprizone induced a significant increase of this cytokine, indicating neuroinflammation (figures 3(a) and 3(b) ; p < 0.05, compared to control group). animals that received cuprizone plus sildenafil also had a significant increase of tnf-, compared to control (p < 0.01). this enzyme was expressed in a minimal amount in the cerebellum of the inos control group (figures 3(c) and 4(a)). cpz administration induced a significant increase in cox-2 expression, compared to control (figures 3(c) and 3(d) ; p < 0.01). sildenafil treatment did not decrease cox-2, which remained high in comparison with the control group (figures 3(c) and 3(d) ; p < 0.01). ih labeling revealed the expression and location of cox-2 (figures 4(a)4(c)), which was mainly found in the white matter of the cerebellum. the control group had a very low expression of this enzyme (figure 4(a)), while treated animals had a high expression of cox-2 in white matter (figures 4(b) and 4(c)). cuprizone increased iba-1, il-1, and ifn- expression in the cerebellum of inos mice. while sildenafil decreased the expression of these proteins, the level of expression remained above that of control animals. there was physiological expression of iba-1 in the cerebellum of inos control animals, with cells with processes that were typically branched, thin and weakly labeled (arrow, figure 4(d)). cuprizone treatment induced a stronger expression of iba-1 (figure 4(e)), compared to the control group, with thicker and more intensely labeled microglial processes. these processes lost their typical thin branched appearance, indicating that the cell phenotype had acquired activated characteristics. sildenafil together with cpz decreased iba-1 expression, and the microglia exhibited thin, highly branched processes, typical of a latent state (figure 4(f)). immunoblotting for il-1 and ifn- revealed basal expression of these cytokines in the inos control group (figures 5(a) and 5(c)). cuprizone strongly increased the expression of these cytokines (both p < 0.001), compared to the control group (figures 5(a)5(d)), which indicates neuroinflammation. sildenafil treatment resulted in a significant decrease of il-1 and ifn- compared to the cuprizone group (p < 0.01). however, the levels of il-1 and ifn- remained higher in the sildenafil - treated group when compared with baseline levels of the control group (p < 0.01 and p < 0.001, resp.). mice without inos underwent a significant increase in enos expression, compared to wild - type animals. untreated mice inos (control group ; p < 0.01) and inos animals treated with cpz or cpz + sild (both p < 0.001) showed a significant increase in enos levels, compared with wild - type mice that did not undergo treatment. the expression of enos in inos mice treated with cpz and cpz plus sildenafil was not significantly higher when compared to inos control animals but showed a propensity to increase (figures 6(a) and 6(b)). gstpi, a marker of myelinating oligodendrocytes, was expressed in the cerebellum of the control group (figure 7(a)). after treatment with cpz, this marker decreased significantly (p < 0.001) compared to the control group, suggesting an impairment of mature oligodendrocytes and consequent myelin damage. sildenafil treatment together with cpz induced partial recovery of the gstpi marker, indicating that sildenafil had a protective effect on mature oligodendrocytes. in the sildenafil group, gstpi decreased in comparison with control (p < 0.001) but increased in comparison to the cuprizone group (p < 0.001 ; figures 7(a) and 7(b)). myelin sheath structure was disorganized in animals without inos which did not undergo treatment (control). interestingly, inos animals without treatment (control) had moderate disorganization of the myelin structure and ultrastructure (figures 8(a), 8(d), and 8(g)). standard lfb staining showed that the control group inos had vacuoles in white matter (arrow in figure 8(a)), resulting in inhomogeneous and disorganized tissue. qualitative analysis of ultrathin cerebellum sections by tem revealed that the myelin sheath was often shredded, with blanks, and without the characteristic lamellar pattern (arrows in figures 8(d) and 8(g)). cuprizone - treated animals exhibited more severe damage to myelin structure and ultrastructure (figures 8(b), 8(e), and 8(h)). lfb staining (figure 8(b)) showed vacuoles (arrows) and spaces (arrowhead) as slits in white matter, characteristic of highly disorganized tissue. tem revealed that cpz caused serious damage to the myelin sheath ultrastructure, which had numerous spaces between the shreds in practically all fibers (represented by arrows in figures 8(e) and 8(h)). simultaneous treatment with sildenafil and cpz resulted in a noticeable improvement of myelin organization (figures 8(c), 8(f), and 8(i)). white matter was more homogeneous, presenting fewer and, in general, smaller vacuoles and slit - like spaces (figure 8(c)). ultrathin section analysis revealed a more preserved myelin sheath which rarely showed signs of shredding. the cuprizone model is characterized by primary and reversible demyelination, due to peripheral immune system - independent myelin injury. in this model, demyelination is accompanied by a well - characterized sequence of events involving the depletion of mature oligodendrocytes, microglia activation, and astrocyte proliferation. therefore, demyelination and resident neuroinflammation induced by cuprizone in rodents have been widely used as a model for ms [20, 27 ]. in the present study, the usefulness of the cuprizone model is considerable as it allows evaluation of the role of the inos / no - sgc - cgmp pathway in the inflammation and demyelination mediated by resident cns cells. the cerebellum was chosen for analysis, as it is an important cns affected region in ms patients, revealing severe white matter atrophy [28, 29 ]. the present data, relating to inos animals, will be discussed with reference to this previous study. (2012) showed that in c57bl/6 wild - type (wt) mice cuprizone induced tissue damage, increased gfap, iba-1, and cox-2 expression, and caused demyelination, in comparison to the control group. however, cuprizone did not affect the expression of cytokines (tnf-, ifn-, il-1, and il-2) in wt mice. in the previous study by the authors, sildenafil reduced gfap and iba-1 expression in comparison to the cuprizone group, preserved myelin and axon ultrastructure, and significantly downregulated ifn-, tnf-, il-1, il-2, and cox-2 expression in comparison to the control and/or cuprizone groups. the previous results demonstrated the protective effect of sildenafil on the cerebellum. it was considered important to investigate the role of no in the ms - model and the effects of sildenafil more profoundly. therefore, in the present study, the relationship between inosnull mice, the ms - model, and the effects of sildenafil in the cerebellum was investigated. in the absence of inos iba-1, il-1, and ifn-. in addition, cuprizone intoxication decreased gstpi, a marker for myelinating oligodendrocytes, damaged myelin, and induced tremors, abnormal walking, and posture. this data indicates that cuprizone intoxication occurred even without the inos - no system and was stronger than in wt mice, where cuprizone did not increase cytokine expression. it was hypothesized that, in the absence of inos, enos may be overexpressed as a compensatory mechanism.. showed that treatment with endotoxin influenced nos expression, upregulating inos and, simultaneously, downregulating enos. in fact, it was found here that enos was strongly expressed in inos animals in comparison with wt mice. the enos levels remained high after the administration of cuprizone and cuprizone plus sildenafil. in normal conditions, low levels of no produced by both enos and nnos participate in cell signaling and regulate physiologic processes. however, enos overexpression (and consequently, constant high concentration of no) can be responsible for myelin changes and proinflammatory susceptibility in inos animals. on the other hand, inos possesses an important feedback mechanism in inflammatory conditions, when the increase of this enzyme is self - regulated, and induces a reduction of some proinflammatory proteins [3235 ]. the inhibition of inos activity induces enhancement of il-1, il-6, and tnf- levels and, subsequently, a persistent increase of inos expression, downregulating the tnf receptor. in the present study, absence of inos may explain increased tnf-, ifn-, and il-1 after cuprizone treatment in inos mice, while cuprizone did not increase these cytokines in wt mice. another hypothesis for explaining the more severe inflammation induced by cuprizone in mice without inos is the absence of inos feedback mechanism. interestingly, although sildenafil had a low anti - inflammatory effect on inos mice, it considerably improved the myelin structure of mice without inos. cuprizone is a copper chelator which leads to direct oligodendrocyte death with subsequent demyelination. in this model, oligodendrocyte death and demyelination are independent of immune and inflammatory response. it was found that cgmp analog (8-br - cgmp) protects differentiated oligodendrocytes from death initiated by staurosporine, thapsigargin, or kainate. it is possible that sildenafil, through the accumulation of cgmp, has a direct beneficial effect on oligodendrocytes, protecting these cells and improving myelination, independent of its anti - inflammatory effects. in conclusion, the findings of the present study show that inos mice are more susceptible to cuprizone intoxication due to the potential involvement of two mechanisms : (1) inos - negative feedback mechanism in inflammatory conditions is absent and, consequently, proinflammatory proteins, such as cytokines and cox-2, are excessively increased ; (2) enos is overexpressed by a compensatory mechanism and generates chronically high levels of no, damaging the tissue. also, the results of the present study suggest that sildenafil may exert its anti - inflammatory effects mainly through inos inhibition, by cgmp - inos feedback. in addition, sildenafil may have a direct protective effect on oligodendrocytes. further studies are required to explain the molecular mechanism of sildenafil protection in the central nervous system. | we recently demonstrated that sildenafil reduces the expression of cytokines, cox-2, and gfap in a demyelinating model induced in wild - type (wt) mice. herein, the understandings of the neuroprotective effect of sildenafil and the mediation of inos / no system on inflammatory demyelination induced by cuprizone were investigated. the cerebella of inos/ mice were examined after four weeks of treatment with cuprizone alone or combined with sildenafil. cuprizone increased gfap, iba-1, tnf-, cox-2, il-1, and ifn- expression, decreased expression of glutathione s - transferase pi (gstpi), and damaged myelin in inos/ mice. sildenafil reduced iba-1, ifn-, and il-1 levels but had no effect on the expression of gfap, tnf-, and cox-2 compared to the cuprizone group. sildenafil elevated gstpi levels and improved the myelin structure / ultrastructure. inos/ mice suffered from severe inflammation following treatment with cuprizone, while wt mice had milder inflammation, as found in the previous study. it is possible that inflammatory regulation through inos - feedback is absent in inos/ mice, making them more susceptible to inflammation. sildenafil has at least a partial anti - inflammatory effect through inos inhibition, as its effect on inos/ mice was limited. further studies are required to explain the underlying mechanism of the sildenafil effects. |
diabetes mellitus refers to a group of common metabolic disorders that share the phenotype of hyperglycemia. it is estimated that there are currently 285 million people with diabetes worldwide and this number is set to increase to 438 million by the year 2030. epidemiological data indicate that all nations, rich and poor, are suffering the impact of the diabetes epidemic. the impact is worse in those countries that are socially and economically disadvantaged. in africans 80% of diabetes patients most of them may be asymptomatic or have mild symptoms which they ignore or attribute to other myths. information on chronic complications of diabetes in sub - saharan africa is scarce ; however, its incidence has gone hand in hand with the growing disease prevalence, demonstrating the importance of assessing complications. factors contributing to optimum disease management included age, complexity of treatment, duration of disease, and psychosocial issues. ethiopia is the second most populous country in sub - saharan africa where more than 80% of the population lives in the country side. in ethiopia, the estimated prevalence of diabetes mellitus (dm) in adult population of ethiopia is 1.9%. the pharmacological approach is used when the nonpharmacological approach fails to achieve the desired outcome. pharmacotherapy for type 2 dm has changed dramatically in the last few years with the addition of several new drug classes and recommendations to achieve more stringent glycemic control. recently initiation of metformin in all patients with t2d at diagnosis along with appropriate life style modification has been introduced where there is no contraindication. in addition to metformin, oha, injectable insulin, amylin analogs, and inhaled insulin are other options for treatment of t2d. the choice of therapy for type 1 dm is simple : all patients need insulin. however, how that insulin is delivered to the patient is a matter of considerable practice difference among patients and clinicians. nonadherence rates are relatively high across disease states, treatment regimens, and age groups. the drop in adherence is noted to be most dramatic after the first six months of therapy among patients with chronic conditions such as diabetes mellitus. a systematic review of studies on adherence to medication among diabetes patients showed that average adherence to oral antidiabetes medications ranges from 36% to 93%, while adherence to other treatment recommendations especially dietary adherence among these patients remains poor. medication may contribute to nonadherence secondary to its side effects and cost, while poor patient - healthcare provider relationships may also be a major determinant of nonadherence. poor adherence to medication regimens is common, contributing to substantial worsening of disease, death, and increased healthcare costs. hence, practitioners should always look for poor adherence and can enhance adherence by emphasizing the value of a patient 's regimen, making the regimen simple and customizing the regimen to the patient 's lifestyle. nonadherence, poverty, lack of knowledge, and poor follow - ups are the main factors observed in poor glycemic control. nonadherence to prescribed medication schedule has been and continues to be a major problem in the world. in chronic disease, it has been described as taking less than 80% of the prescribed treatment. previous studies have found adherence to diabetes treatment generally to be suboptimal ranging (23%77%). in ethiopia, the world health organization (who) estimated the number of diabetic cases in ethiopia to be 800,000 by the year 2000, and the number is expected to increase to 1.8 million by 2030. there is a continuing need to routinely assess the likely reasons for nonadherence among patients with diabetes in clinical practice. this is especially important in developing countries such as ethiopia where economic instability and inadequate access to healthcare facilities might have led to the increased incidence of medication nonadherence. in resource - limited countries like ethiopia, the preponderance of economic instability, low literacy level, and restricted access to healthcare facilities might have led to the increased incidence of medication nonadherence. to the best of our knowledge, evidence - based research that evaluates medication adherence among patients with diabetes in ethiopia is scanty. in addition to this, we have the following.most of the previous studies were done in developed countries, leaving the gaps in knowledge about the prevalence and factors that may be associated with adherence to diabetic patient in ethiopia.few studies on antidiabetic medication adherence have been reported from ethiopia.the sample size used in some of the studies is very small and the method of selection of participants in some cases has led to highly selective samples that are not representatives of the population from which they are picked.therefore the purpose of this study is to fill the gap in knowledge of the adherence and contributing factors and the association between them in diabetic patients in adama hospital. most of the previous studies were done in developed countries, leaving the gaps in knowledge about the prevalence and factors that may be associated with adherence to diabetic patient in ethiopia. the sample size used in some of the studies is very small and the method of selection of participants in some cases has led to highly selective samples that are not representatives of the population from which they are picked. determining the significance of nonadherence and identification of the factors leading to nonadherence to a prescribed treatment through a continued research can assist in planning interventions to overcome the barriers. hence, this study will be carried out togive information on patient nonadherence and related factors that may help in the healthcare system for whom it concerns;give information based on the respondent 's responses on different aspects of the disease that may help in further study by policy makers and some concerned governmental bodies;design an interventional method that can solve problems related to nonadherence;give recommendations on how to manage problems associated with nonadherence in diabetic patients;help as a baseline for further study on patient 's adherence and determine various adherence and nonadherence issues. give information on patient nonadherence and related factors that may help in the healthcare system for whom it concerns ; give information based on the respondent 's responses on different aspects of the disease that may help in further study by policy makers and some concerned governmental bodies ; design an interventional method that can solve problems related to nonadherence ; give recommendations on how to manage problems associated with nonadherence in diabetic patients ; help as a baseline for further study on patient 's adherence and determine various adherence and nonadherence issues. the aim of this study was to determine the magnitude of nonadherence and its contributing factors among diabetic patients attending dm clinic in adama referral hospital. specific objectives are as follows : to assess adherence to medication among ambulatory patients with diabetes;to identify the probable reasons for nonadherence with a view to develop intervention to improve adherence;to determine the relationship between nonadherence and various sociodemographic and other drug and patient related factors (figure 1);to describe the prevalence of different perceived problems of respondents with disease or the medication and on the healthcare system;to provide the baseline data for future study. to assess adherence to medication among ambulatory patients with diabetes ; to identify the probable reasons for nonadherence with a view to develop intervention to improve adherence ; to determine the relationship between nonadherence and various sociodemographic and other drug and patient related factors (figure 1) ; to describe the prevalence of different perceived problems of respondents with disease or the medication and on the healthcare system ; to provide the baseline data for future study. the study setting was adama referral hospital, east showa, oromia national regional state, ethiopia. adama is located 99 km southeast of addis ababa (the capital city of ethiopia). it was established in 1946 by italian missionaries and formerly called haile mariam mammo memorial hospital. it is a medical college and teaches accelerated medicine, emergency surgery, and anesthesia nurses. the hospital gives services for about 5 million people in east and southern parts of oromia, afar, somali, and southern nation, nationalities, and peoples ' region (snnp). now the hospital has 465 different workers to give different services, of which 194 are administration workers. there are specialist in different field (23), practitioners (gp) 36, nurses (116), laboratory workers (20), x - ray professionals (5), physiotherapists (2), sanitarians (2), biomedical professionals (1), midwifery (16), anesthesia nurses (9), health officers (9), psychiatry nurses (3) and masters in different fields (14). the data obtained from the hospital shows that an average of 723 ambulatory diabetes patients attended the clinic for follow - up. this study was done for a period of one month from 15th of april to 15th of may 2014. a prospective cross - sectional study was conducted at the ambulatory diabetic clinic of adama referral hospital (arh). inclusion criteria include ambulatory patients whoare on antidiabetic medications for more than six months;consented to participating in the study;will attend the diabetic clinic during the study period. are on antidiabetic medications for more than six months ; consented to participating in the study ; will attend the diabetic clinic during the study period. exclusion criteria are as follows : unconscious patients;patient age less than 18 years;very ill patients. unconscious patients ; patient age less than 18 years ; source population was diabetic patients being treated at adama referral hospital. study population included all diabetic patients receiving antidiabetic medication in the ambulatory diabetic clinic during the study period. the sample size was calculated using single population proportion formula as follows : (1)n = z2p(1p)w2, where n = is desired sample size for population > 10,000, z = is standard normal duration usually set as 1.96 (which corresponds to 95% confidence level), and negative prevalence = 1 0.5 = 0.5, w = degree of accuracy desired (marginal error is 0.05 ; then the sample size is n = (1.96)0.5(1 0.5)/(0.05) = 384.16 = ~384). since the total population is 10,000, and nf is estimated study population. then 10% contingency the study involves cross - sectional interview of consecutive diabetic patients who visit the dm clinic during the study period. patients included in the pretest were subsequently excluded from the study. after the pilot testing, some question - items in the questionnaire were modified and reframed to ensure validity of the instrument (table 3). the questionnaire, which was the instrument of the study, was pretested on diabetes patients. this tool consists of information about the sociodemographic characteristics of the respondents (figure 4), the pattern of drug adherence, and factors contributing to nonadherence. it also consists of information related to drugs prescribed, dose, frequency, and patients ' mean fasting plasma glucose reading at the last clinic visit. each questionnaire containing 25 questions that took an average of 5 to 10 minutes to fill was used in the interview. it was designed to have two sections ; the first section elucidated the sociodemographic characteristics of diabetic patients while the second section contained questions that assess the adherence patterns and the likely reasons for patients ' nonadherence to prescribed medications. independent variables are as follows : age, religion, educational level (class year),marital status, income, residence. educational level (class year), dependent variables are as follows : knowledge about the medications, knowledge about the disease, outcomes of treatment with antidiabetic drugs. knowledge about the medications, knowledge about the disease, outcomes of treatment with antidiabetic drugs. data were sorted, coded, and entered into predictive analytics software (pasw) (formerly spss) window version 16 for management and analysis. descriptive statistics including frequency, mean, range, and standard deviation were used to summarize patients ' baseline sociodemographic data and evaluate distribution of responses. before data collection to conduct this study ethical approval was obtained from ambo university college of medicine and health science research team leader and the letter was submitted to adama referral hospital medical director office prior to the beginning of undertaking the study in the area. all the study participants were informed about the purpose of the study ; their right to refuse was maintained. the confidentiality of the data obtained was assured and the name and address of the patient were omitted from the questioner. a total of 270 patients were interviewed ; one hundred thirty - one (48.5%) were females. the mean age for the studied population was 55.11 (sd = 14.24) years (range : 19 to 85 years). the education profile of these patients revealed that 74 (27.4) had no formal or informal education while 99 (36.7%) have secondary or postsecondary education. sixty - six (24.4%) were retirees from private and public establishments and 33 (12.2%) were government employees. a total of 184 (68.1%) of the patients included in the study were married. thirty - eight (14%) of the patients were younger than 40 years, one hundred thirty - five (50%) were between 40 and 60 years and 97 (35.9%) were older than 60 years. approximately 195 (72.2%) of patients self - reported adherence to their antidiabetic drug regimens. in the pattern of drug use, 170 (62.96%) of patients have excellent adherence, 25 (9.26%) have good adherence, and 75 (27.8%) have poor adherence (table 4 and figure 2). a total of 59 (21.8%) of the participants ascribed their nonadherence to forgetting to take their medications. other factors include use of traditional and/or religious medicines, 48 (17.8%), and lack of finances, 39 (14.4%). of the total population, 248 (91.85%) of the patients reported that they monitored their blood glucose levels monthly at the dm clinic of the hospital on a regular basis. the proportion of male patients adherent to their antidiabetic medications was found to be lower 97 (69.78%) compared to the female patients (74.81%), but the difference was not statistically significant (p > 0.05). adherence to antidiabetic drugs was found to be higher among graduates (postsecondary, e.g., college (80.77%) and university (73.91%)) compared to illiterate and those with up to secondary school education (71.04%), but this finding was not statistically significant (p > 0.05). it was also noted that patients with a duration of diabetes 5 years (82.07%) were more compliant to their medication than those with diabetes > 5 years (60.8%), which was found to be statistically significant (p = 0.003) (table 2 and figure 3). investigation of association between respondents ' sociodemographic characteristics and estimates of nonadherence, such as and forgetfulness of medication doses, showed that age and marital status seemed to have statistically significant influence (p 6 years, respectively. this finding was consistent with the study from uae and india indicating a negative relationship between the duration of diabetes and patient adherence to drug therapy [11, 14 ]. during the early stage of the disease patients tend to be more committed to their disease, but their commitment does not last long since they adapt the burden and deterioration continues. the most common reasons for nonadherence to medications were modifiable factors that could be overcome by adopting suitable measures. forgetfulness was the most commonly mentioned reason for noncompliance, similar to the findings of studies from uae, nigeria, and india [13, 14, 16 ]. in contrast, a study from india reported self - decision, 35.08%, as the main causal factor for nonadherence to antidiabetic medications. this barrier can be overcome by assisting patients in organizing their medications with pillboxes and dosing alarms and family members can assist in medication adherence for the elderly and those taking multiple medications. the high cost of medication is agreed upon by the majority of the patients as the most important reason preventing optimal adherence. in this study, 37.1% in ethiopia where the none adherence is due to financial difficulty [8, 17 ]. ethiopia is a developing country in which most of the population has a lower income and this is one factor that contributes to the limited health service in general and dm management in particular. the identified causes of nonadherence to taking antidiabetic medications as prescribed were nature of work / busy schedule of work, patient dissatisfaction, cost of drug, and forgetfulness and were found to be 13.85%, 10.77%, 21.54%, and 53.85%, respectively, in this study. similarly, nonadherence to appointment keeping was caused by forgetfulness, 9.53%, nature of work and busy schedules, 42.86%, travelling away from home, 42.86%, and being intentional, 4.76%. patients who come from rural areas and those elderly patients who do not have care giver have difficulty of keeping clinic appointments. similar study identified busy work schedules especially for patients in the working population as one of the reasons why some patients do not take their antidiabetic medications, 16.19%. the majority of the patients were on monotherapy, the same result as a study from ethiopia. but the monotherapy mostly prescribed in this case was insulin (47%) unlike the above study in which glibenclamide (74.3%) was used. the present study includes both type one and type two diabetes patients and it is not surprising that insulin is used in most patients ; that is, it is used in both types i and ii (when necessary) and also the prevalence of the types of dm should be considered in these two areas. this is in agreement with the study in nigeria that showed the same combination therapy in 36.8% of patients. the practice of self - monitoring of blood glucose levels by patients is indicative of their commitment to diabetes management. the study showed that 41.1% of the patients had adequate glycemic control and it is consistent with another study which reported adequate glycemic control in 41.8% of type 2 diabetic patients. although hba1c is the established gold standard, fpg level is being used to assess and monitor glycemic control in this hospital. the glycosilated hemoglobin (hba1c) test was not routinely recommended for patients probably on account of the high cost of the test in the hospital or because it may not be part of the established guideline within the hospital. this study was able to show the main factors that can undermine the desired outcomes of diabetes pharmacotherapy in diabetic patients by decreasing adherence to their medications. these factors can be patient related such as (forgetfulness, intentional omission of dose) and drug related (cost, side effects, and multiple drug therapy especially in those with comorbidity), all of which are modifiable factors. however as the result from this study indicates the desired blood sugar level could not be controlled and maintained adequately. this was because of poor adherence to the prescribed drug regimen and poor knowledge and practice of successful self - management. adequate, clear, and quality information regarding diabetes and antidiabetic medications should be provided to all diabetic patients in order to make the patient aware of future complications of the disease and the benefits of drug therapy as the factors related to nonadherence in this area are modifiable and associated with low knowledge about the disease and treatment.the practice of cost - free medication service to the patients that can not afford to buy it in this hospital is appreciable as cost of drug is among the factors hindering adherence but the inclusion of other needy patients should be considered since there are still large number of poor patients who are losing hope of their future.the role of health professionals at this point should be considerable in providing the most cost - effective, the safest, and the most effective available medication.patients should be encouraged to appropriately use antidiabetic drugs and regular awareness should be created regarding the benefits of using them there by preventing the intentional nonadherence.the medication adherence rate in this study was 72.2%. although the exact estimate of adherence may not be accurately depicted, as this is a small cross - sectional study, future large - scale studies are needed for further understanding of the problem and development of more effective interventions. adequate, clear, and quality information regarding diabetes and antidiabetic medications should be provided to all diabetic patients in order to make the patient aware of future complications of the disease and the benefits of drug therapy as the factors related to nonadherence in this area are modifiable and associated with low knowledge about the disease and treatment. the practice of cost - free medication service to the patients that can not afford to buy it in this hospital is appreciable as cost of drug is among the factors hindering adherence but the inclusion of other needy patients should be considered since there are still large number of poor patients who are losing hope of their future. the role of health professionals at this point should be considerable in providing the most cost - effective, the safest, and the most effective available medication. patients should be encouraged to appropriately use antidiabetic drugs and regular awareness should be created regarding the benefits of using them there by preventing the intentional nonadherence. although the exact estimate of adherence may not be accurately depicted, as this is a small cross - sectional study, future large - scale studies are needed for further understanding of the problem and development of more effective interventions. | the objective of this study was to determine the magnitude of nonadherence and its contributing factors among diabetic patients attending the diabetic clinic in adama hospital. methods. this descriptive cross - sectional study was carried out among patients with diabetes mellitus attending the diabetes mellitus clinic of adama referral hospital. every other patient was selected and data regarding their medication adherence was collected using a structured interview. data analysis was carried out using spss-16. result. the response rate from this study was 98.3%. a total of 270 patients were interviewed ; 51.5% were males. a total of 68.1% of the patients included in the study were married. 14% were younger than 40 years, and 50% were between 40 and 60 years. 21.8% of the participants ascribed their nonadherence to forgetting to take their medications. patients with duration of diabetes 5 years (82.07%) were more compliant to their medication than those with > 5 years (60.8%), which was found to be statistically significant (p = 0.003). insulin, 47%, and glibenclamide plus metformin, 43.7%, were the most commonly prescribed mono- and combination therapies, respectively. common comorbid conditions include hypertension, 148 (54.82%), and visual impairment, 89 (32.96%). the proportion of male patients adherent to their antidiabetic medications was found to be lower than 69.78% compared to the female patients (74.81%), but the difference was not statistically significant (p > 0.05). conclusion. most diabetic patients are currently being managed with the most effective available drugs. however the result from this study indicates that the desired blood sugar level could not be controlled and maintained adequately. this was because of poor adherence to the prescribed drug regimen and poor knowledge and practice of successful self - management. |
sudden infant death syndrome (sids) is a diagnosis of exclusion defined as " the sudden death of an infant under one year of age that remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene and review of the clinical history " (1). although the cause of death should be diagnosed as sids only after a thorough examination has been conducted, many cases have been diagnosed as sids despite failure to fulfill all the criteria for sids diagnosis. to address this problem, the medical community established the diagnosis sudden unexpected death in infancy (sudi), defined as sudden unexpected death occurring before 12 months of age (2). analysis of epidemiological data has elucidated modifiable risk factors for sids, including the placement of an infant to sleep in certain positions, specifically in a prone or side position, on certain surfaces, particularly on a soft surface, or in a bed with one or more other individuals, as well as the exposure of an infant to nicotine via maternal smoking before birth and second - hand smoke after birth (3 - 5). since the identification of these risk factors, nevertheless, sids remains the leading cause of death of infants under one year of age in many countries (6 - 8), having been reported to be the cause of death of between 0.1 and 0.8 per 1000 live births in developed countries (3). although many epidemiological reviews of sids prevalence have been conducted in an international context, no coronial investigation has been conducted in a korean context. to fill this research gap, this study reviewed cases of sids referred by the national forensic service and seoul national university college of medicine for autopsy from 1996 to 2008 to identify demographic and sleeping environmental factors that may be risk factors for sids. the sids cases analyzed were selected from review of the records of the national forensic service and seoul national university college of medicine. the inclusion criteria for all cases were age 8 to 364 days at time of death and sudden and unexpected death. any cases for which a specific cause of death was subsequently established at autopsy were excluded. the data collected included time of death, position when found deceased, position placed to sleep before death, and sleeping surface. data were also collected regarding whether the sids occurred during bed - sharing, defined as a specific type of co - sleeping pattern in which an infant sleeps with another individual on the same surface (9), and, if so, whether the individual with whom the infant was sleeping had consumed alcohol prior to sharing a bed with the deceased infant. fisher 's exact test was used to compare categorical variables when comparable data were available. the temporal changes of bed - sharing and sleeping position were evaluated using logistic regression model and multinomial logistic regression models, respectively. the study protocol was reviewed by institutional review board of the seoul national university hospital (e-1111 - 031 - 385). the study protocol was reviewed by institutional review board of the seoul national university hospital (e-1111 - 031 - 385). table 1 shows the demographic data regarding the sids cases reviewed. regarding the number of cases, 355 post - mortems were classified as sids between 1996 and 2008, and although no significant trend regarding an increase or decrease in the number of cases could be identified over the study period, 209 (58.9%) sids cases were observed in the winter and spring seasons. regarding the characteristics of the cases, 193 (54.4%) male and 162 (46.6%) female cases diagnosed as sids occurred at a median age of 17 weeks, with 135 cases (38.0%) of sids occurring under 3 months of age. among the 193 cases (54.4%) for which maternal age had been reported, the median maternal age was 28 yr (range 18 to 43 yr). of the 183 cases (51.5%) for which feeding pattern had been reported, 23 infants (14.2%) had been breastfed, 140 (76.5%) had been fed powdered formula, and 17 (9.3%) had been both breastfed and fed powdered formula. of 293 sids cases for which time when found deceased was known, 109 infants (37.2%) had been discovered between 0601 and 1200h, 71 (23.2%) between 1201 and 1800h, 43 (14.7%) between 1801 and 2400h, and 70 (23.9%) between 2401 and 0600h. of the 168 (47.3%) of cases for which sleeping position before death had been reported, 75 (44.7%) cases had been placed in a prone or side sleeping position, among which 49.8% had been found in a prone position at the time of death (table 2). analysis of the data indicated no tendency toward an increase or decrease in placement in a prone or side sleeping position over the study period (or, 1.090 ; 95% ci, 0.960 - 1.243 ; p = 0.178) (fig. 1). as can be observed in table 3, which shows the data regarding sleeping environment, only 9.4% of infants had been placed to sleep in a bed intended for infants only, such as a cot or bassinet, with the majority being found in a blanket on the floor or in an adult bed. this finding reflects a korean tradition of placing an infant on a blanket over a korean - style floor (ondol). among the cases for which bed - sharing had been reported, 121 (59.3%) of deaths had occurred in a bed - sharing situation. of the cases who had died during bed - sharing, 54 (44.6%) cases had been under 3 months of age, a significantly greater number than those who had died while not bed - sharing (p = 0.028). thirty one (25.6%) of bed - sharing sids deaths had occurred during bed - sharing with 2 or more individuals and 21 (17.4%) cases had occurred during bed - sharing with an individual under the influence of alcohol. there was a statistically significant increasing trend (or, 1.087 ; 95% ci, 1.004 - 1.777 ; p = 0.04) in bed - sharing over the study period (fig. 2). of the 52 infants who had been placed in a supine position before death, 28 had been bed - sharing with 1 or more individuals. regarding the reason for bed - sharing, breastfeeding was reported for 34 (22.5%) cases of all sids. several international studies have found that the promotion of " back - to - sleep " campaigns based on the findings of many epidemiological studies has led to a dramatic decrease in the global prevalence of sids over the last 2 decades (10, 11). however, few studies have examined the prevalence of sids specifically within korea (12, 13), and no coronial data regarding sids in korea have been reported. to redress this lack of research within a korean context, we examined the factors associated with sids cases that had been reported to the national forensic services and seoul national university college of medicine, the majority of which had occurred in the seoul - gyeonggi region of korea, between 1996 and 2008. analysis of the data indicates that the majority of the deaths due to sids had occurred while the infants had been sleeping in a hazardous sleep environment. while many were found in a prone sleeping position, which has been reported as one of the established risk factors for sids (10), a recent study reported that risk of sids in a side position is of a similar magnitude to that of a prone position (14). the risk posed by sleeping in a side position might be due to its inherent instability, as it allows the infant to easily move into a prone position. therefore, the american academy of pediatrics (aap) strongly recommends that infants always be placed in a supine sleeping position (15). among the cases in this study, 55.4% (93 cases) had been placed to sleep in a prone position, a rate much higher than rates previously reported, which range from 13% to 43% (16 - 20), and 17.3% (29 cases) in a side position. analysis of the data indicated no tendency toward a change in sleeping position to the recommended position (supine) over the 13-yr study period. interestingly, 34% (108 cases) of the sids analyzed in this study occurred outside the home, including in a nursery / daycare setting or a relative 's accommodation, indicating increased risk of sids outside the parental residence. this might be due to infants who sleep outside the home being placed in a sleep environment not specifically arranged for infants and/or being placed in a prone position. the study data support this hypothesis, as analysis of the difference between the prevalence in which the infants in this study had been placed in a prone sleeping position in a setting outside the home compared to that in which they had been placed in a prone position in the home was found to be statistically significant (p = 0.002). among the cases for which bed - sharing had been reported, the prevalence of bed - sharing was 59.3% (121 cases), a much higher rate than those found in cohort - based studies, which range from 16.0% to 50.4% (21 - 24). this finding might be explained by cultural factors, such as a korean belief that bedsharing enables breastfeeding and emotional bonding, and supported by the finding that 22.5% (34 cases) of the mothers in this study reported breast - feeding as the reason for bed - sharing. however, bed - sharing is a known risk factor for sids, especially for infants under 3 months of age, infants who share a bed with an individual under the influence of alcohol, and infants who are subjected to bed - sharing for long durations (4, 11). analysis of the data revealed that 44.6% (54 cases) for which bed - sharing had been reported had been under 3 months of age, a percentage that is statistically significant when compared to that of the non - bed - sharing cases and comprising approximately 69.2% of all cases for which bed - sharing had been reported under 3 months of age. surprisingly, 17.4% (21 cases) occurred while bed - sharing with adult(s) who were under the influence of alcohol, a factor that may have undermined the ability to respond to the infant. indeed, several studies have reported a strong association between alcohol consumption prior to bed - sharing and sids (4, 25). furthermore, there was a significantly increasing trend in bed - sharing over 13-yr study period, suggesting that parents and caregivers should be provided with information regarding bed - sharing as a means to decrease the risk of sids. this suggestion is supported by the aap, which recommends that infants in the first year should sleep in their own bed, ideally a bassinet or crib placed in the parental room (15), as well as the findings of this study, specifically that only 16 (9.4%) infants had been sleeping in their own bed. regarding other risk and protective factors, a recent meta - analysis study reported that exclusive breast - feeding of any duration is protective against sids (26). the prevalence of exclusive breast - feeding in this study was found to be 14.2%, a rate slightly higher than the 10.2% domestic rate reported in 2002 (27). unfortunately, accurate data regarding maternal smoking, which has been identified as a dependent risk factor contributing to sids (28) and the main risk factor for sids during bed - sharing (11), could not be collected. accumulating evidence has linked sids to a convergence of exogenous stressors, including non - recommended (prone or side) sleeping position, a critical development period in homeostatic condition, and dysfunction of cardiopulmonary and/or arousal system (29). a recent study found a significant association between sids and mutations in the cardiac ion - channel protein giving rise to disease, including long qt syndrome (lqts) and brugada syndrome, in 10 to 15% of sids cases (30). although there is no evidence of strong heritability for sids, the genetic alteration that has been observed could lead to vulnerability to sids (3, 29, 30). thus, continued research into the interaction between genetic and environmental factors is critical for sids prevention. a 2004 study using the capture - recapture method to examine the 1998 and 1999 data estimated the rate of sids in korea to be 0.56 per 1,000 live births (12). however, this estimation is questionable due to lack of scientific validity in diagnosis, with many cases having been diagnosed as sids without postmortem examination and death scene investigation. although autopsies are critical in identifying the cause of death whenever an infant dies suddenly from unknown causes, the autopsy rate in korea, which is unknown, is presumed to be extremely low compared to those of other developed countries (3). due to its retrospective design, this study faced a major limitation in data collection. although a postmortem protocol for sids autopsy had been introduced in 2001, it was not widely used until 2006. therefore, many data regarding parental smoking, sleeping surface, and breathing at time of death (i.e., whether the face had been covered) were unavailable for cases that occurred before 2006. in contrast, significantly more and better data were available after 2006 because of increased awareness of the environmental risk factors associated with sids and increased use of the postmortem protocol. specifically, they indicate the need to develop, adopt, and implement 1) a set of standardized guidelines for sids diagnosis ; 2) a protocol for the collection of detailed data from medical doctors, scene investigators, caregivers, and medical examiners to determine the precise cause of death ; and 3) monitoring systems to collect data with which to identify trends in sids prevalence. moreover, they suggest that educational campaigns for sids prevention, which have traditionally - and effectively - emphasized avoidance of bed - sharing and placement in a prone position - should also stress avoidance of all risk factors and be conducted on a nationwide scale using all means of information distribution, including those provided by governmental, media, and medical sources. in conclusion, this first coronial study of sids in korea found that a considerable proportion of deaths due to sids occurred while the infants had been sleeping in an environment characterized by risk factors for sids, particularly placement in a prone or side position and/or in a bed - sharing situation. this finding strongly suggests that immediate focus should be placed on making the sleeping environment safer for the next generation. | this study aimed to elucidate the demographic and sleeping environmental factors associated with sudden infant death syndrome (sids) in korea. the autopsy reports of all sids cases reported to the national forensic service and seoul national university college of medicine between 1996 and 2008 were reviewed for data collection and analysis to identify the risk factors for sids. analysis of the 355 sids cases reported within the study period revealed that of the 168 (47.3%) cases for which sleeping position before death had been reported, 75 (44.7%) cases had occurred after placement in prone or side position. of the 204 (57.5%) cases for which bed - sharing situation had been reported, 121 (59.3%) deaths had occurred during bed - sharing, of which 54 (44.6%) infants were under 3 months of age, a significantly younger age than that of the non - bed - sharing cases (p = 0.0279). analysis of the results indicated no tendency toward an increase or decrease in the use of a prone or side position. rather, there was a statistically significant increasing trend for bed - sharing over the study period (or, 1.087 ; 95% ci, 1.004 - 1.177 ; p = 0.04). these findings indicate the need for nationwide educational programs promoting a safe sleeping environment to enhance sids prevention. |
chloroplasts were isolated from the pea leaves of 1012-d - old plants and purified on silica sol gradients (waegemann and soll, 1991). a standard import assay contained chloroplasts equivalent to 30 g chl in 100 l import mix (330 mm sorbitol, 50 mm hepes - koh, ph 7.6, 3 mm mgso4, 10 mm methionine, 10 mm cysteine, 20 mm potassium gluconate, 10 mm nahco3, 2% (wt / vol) bsa, 3 mm atp, and 110% of reticulocyte lysate in vitro synthesized s - labeled precursor proteins. chloroplasts were reisolated from the import assay by centrifugation at 4c through a percoll cushion (40% [vol / vol ] percoll in 300 mm sorbitol, 50 mm hepes - koh, ph 7.6), washed once in hepes - sorbitol (waegemann and soll, 1991), and used for further treatments. prebinding of precursor proteins to chloroplasts was done under conditions identical to those described above, except that all steps were carried out at 0c. chloroplasts were treated with the protease thermolysin in 300 mm sorbitol, 50 mm hepes - koh, ph 7.6, 0.5 mm cacl2 for 20 min at 4c at 200 g protease / mg chl. the reaction was terminated by the addition of 10 mm edta, and chloroplasts were recovered by centrifugation through a 40% percoll cushion and washed once (joyard., 1983 ; cline., 1984). chloroplasts (equivalent to 200 g chl) were treated with 200 g trypsin (10700 n-benzoyl - l - arginine ethyl estes u / mg from bovine pancrease) in 300 mm sorbitol, 50 mm hepes - koh, ph 8.0, and 0.1 mm cacl2 for 1 h at 20c in a final volume of 200 l. the reaction was stopped by the addition of 1 mm pmsf and a fivefold excess of soybean trypsin inhibitor (marshall., 1990 ; lbeck., chlorophyll was determined (arnon, 1949), and equal amounts of organelles were loaded onto the sds - page on a chl basis. after hypotonic lysis in 10 mm hepes - koh, ph 7.6, chloroplasts were separated into a soluble stromal and a total membrane fraction by centrifugation for 10 min at 165,000 g. soluble proteins were precipitated with tca. import products were analyzed by sds - page (laemmli, 1970) followed by fluorography (bonner and laskey, 1974). separation of envelope and thylakoid membranes was achieved after hypotonic lysis of chloroplasts (see above) by centrifugation for 30 s at 2,000 g. the resulting pellet contained thylakoid membranes. the supernatant was once again centrifuged for 10 min at 165,000 g. soluble proteins were precipitated with tca and treated as described above. the pellet fraction, containing a mixture of envelope and remaining thylakoid membranes, was resuspended in 100 l hepes - koh, ph 7.6, and layered over a 300-l sucrose cushion (1 m sucrose, 10 mm hepes - koh, ph 7.6). after centrifugation for 10 min at 165,000 g, thylakoid membranes had pelleted through the cushion and were pooled with the above thylakoid fraction. the supernatant, including the sucrose cushion, was diluted 1:5 with 10 mm hepeskoh, ph 7.6, and envelope membranes were recovered by centrifugation for 10 min at 165,000 g. cdnas coding for the different hybrid proteins were constructed by recombinant pcr (higuchi, 1990). products were cloned into a vector suitable for in vitro transcription and controlled by dna sequencing (sanger., 1977). the original cdnas coding for piep110 and pssu have been described (lbeck., 1996 ; klein and salvucci, 1992). in vitro transcription was done using either t7- or sp6-rna polymerase, as outlined before (salomon., 1990). proteins were synthesized in reticulocyte lysate in the presence of s - labeled methionine and cysteine (1175ci/ mmol) for 1.5 h at 30c (salomon., overexpression of pssu was done in escherichia coli bl21 (de3) cells using the pet vector system (novagen, madison, wi) (waegemann and soll, 1995). chloroplasts were isolated from the pea leaves of 1012-d - old plants and purified on silica sol gradients (waegemann and soll, 1991). a standard import assay contained chloroplasts equivalent to 30 g chl in 100 l import mix (330 mm sorbitol, 50 mm hepes - koh, ph 7.6, 3 mm mgso4, 10 mm methionine, 10 mm cysteine, 20 mm potassium gluconate, 10 mm nahco3, 2% (wt / vol) bsa, 3 mm atp, and 110% of reticulocyte lysate in vitro synthesized s - labeled precursor proteins. chloroplasts were reisolated from the import assay by centrifugation at 4c through a percoll cushion (40% [vol / vol ] percoll in 300 mm sorbitol, 50 mm hepes - koh, ph 7.6), washed once in hepes - sorbitol (waegemann and soll, 1991), and used for further treatments. prebinding of precursor proteins to chloroplasts was done under conditions identical to those described above, except that all steps were carried out at 0c. chloroplasts were treated with the protease thermolysin in 300 mm sorbitol, 50 mm hepes - koh, ph 7.6, 0.5 mm cacl2 for 20 min at 4c at 200 g protease / mg chl. the reaction was terminated by the addition of 10 mm edta, and chloroplasts were recovered by centrifugation through a 40% percoll cushion and washed once (joyard., 1983 ; cline., 1984). chloroplasts (equivalent to 200 g chl) were treated with 200 g trypsin (10700 n-benzoyl - l - arginine ethyl estes u / mg from bovine pancrease) in 300 mm sorbitol, 50 mm hepes - koh, ph 8.0, and 0.1 mm cacl2 for 1 h at 20c in a final volume of 200 l. the reaction was stopped by the addition of 1 mm pmsf and a fivefold excess of soybean trypsin inhibitor (marshall., 1990 ; lbeck., chlorophyll was determined (arnon, 1949), and equal amounts of organelles were loaded onto the sds - page on a chl basis. after hypotonic lysis in 10 mm hepes - koh, ph 7.6, chloroplasts were separated into a soluble stromal and a total membrane fraction by centrifugation for 10 min at 165,000 g. soluble proteins were precipitated with tca. import products were analyzed by sds - page (laemmli, 1970) followed by fluorography (bonner and laskey, 1974). separation of envelope and thylakoid membranes was achieved after hypotonic lysis of chloroplasts (see above) by centrifugation for 30 s at 2,000 g. the resulting pellet contained thylakoid membranes. the supernatant was once again centrifuged for 10 min at 165,000 g. soluble proteins were precipitated with tca and treated as described above. the pellet fraction, containing a mixture of envelope and remaining thylakoid membranes, was resuspended in 100 l hepes - koh, ph 7.6, and layered over a 300-l sucrose cushion (1 m sucrose, 10 mm hepes - koh, ph 7.6). after centrifugation for 10 min at 165,000 g, thylakoid membranes had pelleted through the cushion and were pooled with the above thylakoid fraction. the supernatant, including the sucrose cushion, was diluted 1:5 with 10 mm hepeskoh, ph 7.6, and envelope membranes were recovered by centrifugation for 10 min at 165,000 g. cdnas coding for the different hybrid proteins were constructed by recombinant pcr (higuchi, 1990). products were cloned into a vector suitable for in vitro transcription and controlled by dna sequencing (sanger., 1977). the original cdnas coding for piep110 and pssu have been described (lbeck., 1996 ; klein and salvucci, 1992). in vitro transcription was done using either t7- or sp6-rna polymerase, as outlined before (salomon., proteins were synthesized in reticulocyte lysate in the presence of s - labeled methionine and cysteine (1175ci/ mmol) for 1.5 h at 30c (salomon., 1990). overexpression of pssu was done in escherichia coli bl21 (de3) cells using the pet vector system (novagen, madison, wi) (waegemann and soll, 1995). the role of iep110 in protein import and its specific topology prompted us to study its import in some detail. the protein sequence of iep110 shows the potential to form a hydrophobic helix in the nh2 terminus (amino acids 100140, fig. 1 b), which seems to anchor the protein into the inner envelope membrane (lbeck., 1996 ; kessler., 1996). initial results had indicated that piep110 uses the general import pathway into chloroplasts ; however, the translation and import efficiencies of full - length precursor of iep110 (piep110) were rather low, so we decided to use a truncated version of piep110, namely the transit peptide of 110 and the nh2-proximal part of mature iep110 (tp110 - 110n ; fig. 1 a), which comprises amino acids 1269, to study its import characteristics. after import of the tp110 - 110n translation product into intact pea chloroplasts under standard import conditions, the terminally processed form was recovered almost exclusively in the envelope membrane fraction (fig. 2 a). processed 110n was resistant to extraction at ph 11.5 (0.1 m na2co3), indicating a stable insertion into the membrane similar to in situ (lbeck., 1996). no 110n was detectable in the soluble protein fraction of chloroplasts, and only very little was detectable in the thylakoid membrane fraction (fig. 2 a, lane 5). under thylakoid isolation procedures such as those used here, these were shown to be contaminated with envelope membranes (keegstra and youssif, 1986 ; joyard., 1991). therefore, we conclude that the low amount of 110n found in the thylakoid fraction results from contamination with envelope membranes. the cooh terminus of iep110 that is exposed to the intermembrane space in intact pea chloroplasts is inaccessible to the noninvasive protease thermolysin, but is degraded by trypsin, which proteolytically penetrates through the outer envelope (lbeck., 1996). imported mature 110n was recovered in a thermolysin - inaccessible but trypsin - accessible manner (fig. 2 b), giving further evidence that tp110 - 110n is correctly translocated, processed, and inserted into the inner envelope membrane. 2 c) using the precursor of the small subunit of ribulose-1,5-bisphosphate carboxylase (pssu), a protein localized in the stroma, show that imported mature ssu is inaccessible to trypsin. these results indicate that the chloroplastic inner envelope was not penetrated by trypsin under these experimental conditions, corroborating earlier results that used the latency of the hill reaction to measure chloroplast intactness after trypsin treatment (lbeck., 1996). we conclude that tp110 - 110n can be used as a bona fide substrate to study the import of piep110 into pea chloroplasts, since both full - length and truncated precursors are targeted to the inner envelope membrane and exhibit identical behavior to extraction at ph 11.5 and sensitivity to trypsin. next, we wanted to know if the targeting information present in the presequence of iep110 is essential for translocation into the organelle and insertion into the inner envelope. therefore, the presequences between 110n and ssu were mutually exchanged, resulting in the constructs tpssu-110n and tp110-mssu (see fig. import experiments into pea chloroplasts clearly show that the transit peptide of iep110 directs the ssu passenger protein into the soluble stroma phase, where it is processed and resistant to thermolysin and to trypsin treatment (fig. 3 a, lanes 27). the import efficiency of tp110-mssu, however, is less than 50% of the authentic pssu. the transit peptide of ssu also directed the 110n domain of iep110 to chloroplasts in the reverse construct (fig. the processed 110n was recovered in a thermolysin - insensitive but trypsin - sensitive manner, indicating its correct insertion and orientation in the inner envelope membrane. we conclude that tp110 contains only stromaltargeting envelope transfer information, and that the topogenic signal for envelope targeting to the inner envelope membrane and correct insertion is present in the 110n domain of iep110. further evidence for this conclusion results from studies that demonstrate that tp110 - 110n import is competed for by the addition of an excess pssu (fig. a similar competition for the import yield can be observed between the s - labeled pssu translation product and an excess of e. coli expressed pssu (fig. 4 b). e. coli expressed pssu was introduced into the import reaction as a ureadenatured protein. while a competition at the level of translocation was always observed, the binding of reticulocyte lysate synthesized translation products to the outer envelope membrane is not competed for to the same extent (fig. this might be caused by a certain amount of nonspecific binding to the chloroplast surface that can not be competed for by denatured (i.e., unfolded) pssu, which might bypass the primary binding site and thus compete only at the level of translocation. 4, a and b), however, clearly demonstrate that pssu and tp110 - 110n use common components of the chloroplast import machinery. the stromal processing protease is a metalloenzyme and can be specifically inhibited by o - phenanthroline (abad., 1989). in vitro processing of pssu and tp110 - 110n by a stromal extract demonstrated that both precursor proteins could be converted to their respective mature forms (fig. furthermore, the processing of both preproteins was inhibited by o - phenanthroline (fig. 4, a c, strongly indicate that piep110 uses the general import machinery and processing system of the majority of chloroplast - targeted preproteins. as shown above, the 110n region contained all the sequence determinants necessary for targeting and insertion into the inner envelope membrane. to distinguish domains within this region that could be involved in either targeting or insertion, 110n was subdivided into n1, which contained the most nh2-proximal amino acids of 110n, and n2, which contained the cooh - proximal portion of the 110n region (details are outlined in fig. the sequence of the n2 subdomain was expressed in frame with tp110 or tpssu, resulting in the hybrid proteins tp110110n2 and tpssu-110n2. when import reactions were performed with either tp110 - 110n2 or tpssu-110n2, processed 110n2 was recovered exclusively in the soluble stromal phase (fig. 5, a and b, lanes 2 and 3), as was also indicated by its resistance to either thermolysin or trypsin treatment (fig. the results suggested that the 110n2 domain did not contain sufficient targeting information for the inner envelope membrane. the 110n1 domain, which also comprises the putative membrane - anchoring helix, could therefore be solely responsible for membrane targeting. a hybrid protein was synthesized which consisted of tp110 fused to the n1 domain, which contained ssu as a cooh - terminal extension and putative reporter for intermembrane space location. when the tp110 - 110n1-mssu translation product was imported into chloroplasts, 110n1-mssu was again largely recovered in the soluble stromal phase. soluble mature 110n1-mssu was resistant to the proteases thermolysin and trypsin. however, membrane - bound 110n1-mssu was resistant to thermolysin but accessible to trypsin, i.e., 110n1 functions as the correct topogenic signal, albeit with low efficiency. the efficiency of membrane targeting and insertion might be strongly enhanced by the 110n2 domain. to test this notion, tpssu-110n - mssu, which contained both the n1 and n2 subdomains, interestingly, processed, mature 110n - mssu was largely recovered in the membrane fraction (fig. 5 d). 110n - mssu was resistant to thermolysin but accessible to trypsin, demonstrating that the hybrid protein attained an in situ like membrane orientation ; i.e., the cooh - proximal portion of 110n - mssu is exposed to the intermembrane space. between 10 and 20% of processed, mature 110n - mssu was recovered as a soluble protein in a trypsin - inaccessible location, i.e., in the stromal phase. up to this point, the data indicate that 110n1 contains the information that anchors the protein into the membrane but functions with low efficiency, while 110n2 in combination with 110n1 strongly increases the yield of membraneinserted 110n, maybe because 110n2 contains essential targeting or sorting information that only works in a cooperative way with 110n1. since processed, mature 110n - mssu was detectable in the membrane as well as in the soluble phase, the following question arose : does 110n - mssu integration into the inner envelope occur via a soluble intermediate, or is a significant portion of 110n - mssu missorted to the stroma ? therefore, s - labeled tpssu-110n - mssu was incubated with intact chloroplasts in the presence of 3 mm atp for 5 min at 0c to allow binding but no translocation. organelles were resuspended in 25c tempered fresh import buffer in the presence of 3 mm atp, and were incubated further at 25c for various times 6, a and b). at the earliest time point during the chase period (30 s), a significant portion (20%) of the labeled protein was recovered as membrane - bound precursor, while about one third was found as soluble processed mature form in the stroma. most of the chloroplastbound precursor was imported during the chase period, and only 5% of the total labeled protein remained on the chloroplast surface. furthermore, the proportion of soluble 110n - mssu intermediate declined steadily and was at the brink of detectability after 10 min. simultaneously, the membrane - recovered portion of 110n - mssu increased to more than 80% of the initially introduced labeled proteins. because of the removal of unbound precursor before the beginning of the chase period, we analyzed only the import and insertion of prebound molecules ; i.e., the degradation of soluble 110n - mssu can be excluded because, otherwise, we should not be able to detect an almost constant amount of radioactivity during the entire chase period (fig. 6 b). in the attempts to observe more of the soluble 110n - mssu protein in the stroma, the chase period was initiated by resuspending the chloroplasts in ice - cold import buffer, followed by a slow warming period. 6, except that at the early time points, 30 s and 2 min, bound tpssu-110n - mssu made up more than 50% of the total labeled protein, while processed 110nmssu showed a 1:1 distribution between the stroma and the inner envelope (data not shown). the final result of the chase period was identical to that described in fig. these data clearly demonstrate that a soluble stroma localized intermediate can be chased to a membrane - bound location with an orientation that most of the protein is exposed to the intermembrane space (see also fig. next, we wanted to know if the targeting information present in the presequence of iep110 is essential for translocation into the organelle and insertion into the inner envelope. therefore, the presequences between 110n and ssu were mutually exchanged, resulting in the constructs tpssu-110n and tp110-mssu (see fig. import experiments into pea chloroplasts clearly show that the transit peptide of iep110 directs the ssu passenger protein into the soluble stroma phase, where it is processed and resistant to thermolysin and to trypsin treatment (fig. 3 a, lanes 27). the import efficiency of tp110-mssu, however, is less than 50% of the authentic pssu. the transit peptide of ssu also directed the 110n domain of iep110 to chloroplasts in the reverse construct (fig. the processed 110n was recovered in a thermolysin - insensitive but trypsin - sensitive manner, indicating its correct insertion and orientation in the inner envelope membrane. we conclude that tp110 contains only stromaltargeting envelope transfer information, and that the topogenic signal for envelope targeting to the inner envelope membrane and correct insertion is present in the 110n domain of iep110. further evidence for this conclusion results from studies that demonstrate that tp110 - 110n import is competed for by the addition of an excess pssu (fig. a similar competition for the import yield can be observed between the s - labeled pssu translation product and an excess of e. coli expressed pssu (fig. 4 b). e. coli expressed pssu was introduced into the import reaction as a ureadenatured protein. while a competition at the level of translocation was always observed, the binding of reticulocyte lysate synthesized translation products to the outer envelope membrane is not competed for to the same extent (fig. this might be caused by a certain amount of nonspecific binding to the chloroplast surface that can not be competed for by denatured (i.e., unfolded) pssu, which might bypass the primary binding site and thus compete only at the level of translocation. 4, a and b), however, clearly demonstrate that pssu and tp110 - 110n use common components of the chloroplast import machinery. the stromal processing protease is a metalloenzyme and can be specifically inhibited by o - phenanthroline (abad., 1989). in vitro processing of pssu and tp110 - 110n by a stromal extract demonstrated that both precursor proteins could be converted to their respective mature forms (fig. furthermore, the processing of both preproteins was inhibited by o - phenanthroline (fig. 4, a c, strongly indicate that piep110 uses the general import machinery and processing system of the majority of chloroplast - targeted preproteins. as shown above, the 110n region contained all the sequence determinants necessary for targeting and insertion into the inner envelope membrane. to distinguish domains within this region that could be involved in either targeting or insertion, 110n was subdivided into n1, which contained the most nh2-proximal amino acids of 110n, and n2, which contained the cooh - proximal portion of the 110n region (details are outlined in fig. the sequence of the n2 subdomain was expressed in frame with tp110 or tpssu, resulting in the hybrid proteins tp110110n2 and tpssu-110n2. when import reactions were performed with either tp110 - 110n2 or tpssu-110n2, processed 110n2 was recovered exclusively in the soluble stromal phase (fig. 5, a and b, lanes 2 and 3), as was also indicated by its resistance to either thermolysin or trypsin treatment (fig. 5, a and b, lanes 47). the results suggested that the 110n2 domain did not contain sufficient targeting information for the inner envelope membrane. the 110n1 domain, which also comprises the putative membrane - anchoring helix, could therefore be solely responsible for membrane targeting. a hybrid protein was synthesized which consisted of tp110 fused to the n1 domain, which contained ssu as a cooh - terminal extension and putative reporter for intermembrane space location. when the tp110 - 110n1-mssu translation product was imported into chloroplasts, 110n1-mssu was again largely recovered in the soluble stromal phase. however, membrane - bound 110n1-mssu was resistant to thermolysin but accessible to trypsin, i.e., 110n1 functions as the correct topogenic signal, albeit with low efficiency. the efficiency of membrane targeting and insertion might be strongly enhanced by the 110n2 domain. to test this notion, tpssu-110n - mssu, which contained both the n1 and n2 subdomains, interestingly, processed, mature 110n - mssu was largely recovered in the membrane fraction (fig. 5 d). 110n - mssu was resistant to thermolysin but accessible to trypsin, demonstrating that the hybrid protein attained an in situ like membrane orientation ; i.e., the cooh - proximal portion of 110n - mssu is exposed to the intermembrane space. between 10 and 20% of processed, mature 110n - mssu was recovered as a soluble protein in a trypsin - inaccessible location, i.e., in the stromal phase. up to this point, the data indicate that 110n1 contains the information that anchors the protein into the membrane but functions with low efficiency, while 110n2 in combination with 110n1 strongly increases the yield of membraneinserted 110n, maybe because 110n2 contains essential targeting or sorting information that only works in a cooperative way with 110n1. since processed, mature 110n - mssu was detectable in the membrane as well as in the soluble phase, the following question arose : does 110n - mssu integration into the inner envelope occur via a soluble intermediate, or is a significant portion of 110n - mssu missorted to the stroma ? therefore, s - labeled tpssu-110n - mssu was incubated with intact chloroplasts in the presence of 3 mm atp for 5 min at 0c to allow binding but no translocation. organelles were resuspended in 25c tempered fresh import buffer in the presence of 3 mm atp, and were incubated further at 25c for various times 6, a and b). at the earliest time point during the chase period (30 s), a significant portion (20%) of the labeled protein was recovered as membrane - bound precursor, while about one third was found as soluble processed mature form in the stroma. most of the chloroplastbound precursor was imported during the chase period, and only 5% of the total labeled protein remained on the chloroplast surface. furthermore, the proportion of soluble 110n - mssu intermediate declined steadily and was at the brink of detectability after 10 min. simultaneously, the membrane - recovered portion of 110n - mssu increased to more than 80% of the initially introduced labeled proteins. because of the removal of unbound precursor before the beginning of the chase period, we analyzed only the import and insertion of prebound molecules ; i.e., the degradation of soluble 110n - mssu can be excluded because, otherwise, we should not be able to detect an almost constant amount of radioactivity during the entire chase period (fig. 6 b). in the attempts to observe more of the soluble 110n - mssu protein in the stroma, the chase period was initiated by resuspending the chloroplasts in ice - cold import buffer, followed by a slow warming period. in general, the results were similar to those described in fig. 6, except that at the early time points, 30 s and 2 min, bound tpssu-110n - mssu made up more than 50% of the total labeled protein, while processed 110nmssu showed a 1:1 distribution between the stroma and the inner envelope (data not shown). the final result of the chase period was identical to that described in fig. these data clearly demonstrate that a soluble stroma localized intermediate can be chased to a membrane - bound location with an orientation that most of the protein is exposed to the intermembrane space (see also fig. our data demonstrate that chloroplasts have the capability to reexport proteins into the inner envelope after their complete import into and processing in the stroma. this is not only a membrane insertion process, but the translocation machinery involved can export a large polypeptide chain across the membrane into the intermembrane space. the ssu reporter peptide in 110n - mssu has a length of 140 amino acids, which is completely translocated across the inner envelope into the intermembrane space, as indicated by its complete sensitivity to trypsin. the components of an export machinery are unknown at the present time, and it remains to be seen if it shares common constituents with the inner envelope import machinery. the identification of a chloroplast - coded, inner envelope localized protein (sasaki., 1993) had indicated previously that an independent transport pathway should exist for this membrane. no data exist as to whether this protein translocates co- or posttranslationally into the inner envelope. tpssu-110n - mssu is translocated into the inner envelope after processing in the stroma as the mature form ; i.e., the export signal is not present in the transit sequence, but internal targeting information is necessary. this topogenic signal is localized in amino acids 38269, most likely as a bipartite signal. the nh2-proximal part (n1, amino acids 38149), which also contains the putative membrane anchor region of iep110, is sufficient for targeting to the inner membrane and proper insertion, albeit with low efficiency. the n2 region of iep110 (amino acids 150269) can not direct proteins to the inner envelope, but remains in the stroma upon import. compartimentation of n1 or n2 upon import is most likely to be independent of the stroma - targeting signal used, since both tpssu and tp110 contain only envelope transfer stroma - targeting information. in combination with the n1 region, n2 directs the protein quantitatively to the inner envelope. we propose that n1 contacts the membrane surface very early and that n2 subsequently initiates the translocation process, e.g., as a start transfer signal. piep110 takes the general chloroplast import pathway, as shown by the mutual exchange of transit sequences between piep110 and pssu. tp110 seems to be less efficient than tpssu, which supports two- to threefold higher import yields. simultaneously, more binding to the chloroplast surface is generally detected in constructs that contain tp110. import into chloroplasts and integration into the inner envelope of piep110 and tpssu110n are rapid processes, and a soluble intermediate was beyond detectability. only when we used tpssu-110nmssu was a soluble intermediate in the translocation pathway clearly visible. while 50% of mature 110nmssu has already reached the inner envelope after a 30-s chase period, the results in fig. 5 clearly establish that soluble mature 110n - mssu can be exported into and across the membrane. two reasons could explain these differences : (a) the passenger protein mssu retards the integration and translocation process because its primary sequence or secondary structure are not well suited for the export machinery ; and (b) the mssu part in 110n - mssu interacts transiently with its natural partners of the pssu import and assembly pathway, e.g., chaperonin 60 or the large subunit of ribulose-1,5-bisphosphate carboxylase. independently of the reason for the kinetic differences in 110n - mssu export, our results show very clearly that the signal responsible for reexport to the inner envelope protein is present in 110n and is stronger than the potential interaction of mssu with stromal proteins. at the moment, it can not be excluded that a fraction of 110nmssu is never released from the membrane before insertion, indicating that parallel mechanisms that are used alternatively might exist, or that the currently available experimental approaches are not elaborate enough to resolve this problem. lowering the temperature during the critical chase period did not result in a block of membrane insertion ; only in a general slowdown of the entire process. therefore, specific inhibitors that block single steps in the process are needed to describe the sequence of translocation and insertion in detail. however, our results demonstrate that a reexport machinery exists in the chloroplasts ' stroma that can cooperate faithfully with an inner envelope machinery. in the future, this soluble intermediate will be used as a tool to search for the components of the reexport pathway. the initial protein import experiments of tpssu-110n - mssu in the presence of nan3 or guanosine nucleotides did not show significant alterations in the yield of inner envelope localized 110n - mssu (lbeck, j., and j. soll, unpublished data). studies of sorting of proteins to the inner mitochondrial membrane have suggested that the yeast cytochrome oxidase subunit va uses a stop - transfer mechanism, i.e., one that never leaves the inner membrane, even during processing by the matrix processing protease (miller and cumsky, 1993 ; see also glick., 1992). sorting of subunit 9 of fo - atpase to the inner membrane of neurospora mitochondria, however, was proposed to occur after complete translocation into the organelle via a conservative sorting mechanism (rojo., 1993). the soluble matrix localization of processed mature subunit 9 of fo - atpase was not analyzed (rojo., 1993 ; see also stuart and neupert, 1996). the soluble intermediate we describe in this study for the translocation of 110n - mssu into the inner envelope might involve a sorting system that is not present in mitochondria, e.g., a sec, nsf, or srp homologue (a) peptide domain combination of various hybrid precursor proteins used in this study and their nomenclature. (aa, amino acids ; tp, transit peptide ; 110n, amino acids 39269 of piep110 ; 110n1, amino acids 39149 of iep110 ; 110n2, amino acids 150269 of piep110). inner envelope targeting and insertion information is contained in the nh2 terminus of iep110. a truncated iep110 precursor, namely tp110 - 110n, comprising amino acids 1269, was used in standard import experiments with purified pea chloroplasts (equivalent to 30 g chl ; a and b). (a) chloroplasts were separated into different fractions containing either envelope membranes (env), soluble stroma (st), and thylakoid membranes (thy). membranes were subsequently extracted with na2co3 at ph 11.5 and further separated into a pellet (p) and soluble fraction (s). (b) inserted, terminally processed 110n is sensitive to the protease trypsin but not to thermolysin. after completion of a standard import reaction, chloroplasts were either not treated (lanes 2 and 3) or treated with protease (thermolysin [th ], lanes 4 and 5 ; trypsin [try ], lanes 6 and 7). organelles were reisolated through a 40% (vol / vol) percoll cushion washed once. chlorophyll concentration was determined, and equal amounts of organelles were used for further analysis. organelles were separated into a soluble stroma (st) and membrane (m) fraction. (c) pssu is imported into the chloroplast stroma, where the processed mature form is resistant to both proteases, thermolysin and trypsin. all experimental conditions are as decribed in b. s - labeled translation product (tl) is shown as an internal standard, 10% of which was added to a standard import reaction. the presequence of iep110 and ssu were mutually exchanged, and the resulting hybrids, tp110-mssu and tpssu-110n, were used under standard chloroplast import conditions. (a) chloroplasts were separated into a soluble stroma phase and a total membrane fraction either before or after treatment with thermolysin or trypsin. (b) the stroma - directing presequence of ssu (tpssu) can not deviate 110n to the stroma. import and subfractions of chloroplasts are as decribed in a. all further experimental conditions and abbreviations are as decribed in fig. (a) tp110 - 110n import into pea chloroplasts was assayed in the absence or presence of increasing pssu concentration. pssuex was synthesized in e. coli and added as a urea - denatured protein to the import assay (final urea concentration 80 mm). import experiments were initiated by the addition of organelles (equivalent to 30 g chl). synthesized pssuex competes the import of reticulocyte lysate made s - labeled pssu with similar efficiency as tp110 - 110n. experimental conditions are as desribed in a. (c) tp110 - 110n and pssu are both processed in vitro by a stromal extract. a stromal processing extract was incubated for either 0 min (lanes 1 and 4) or 90 min (lanes 2, 3 and 5, 6) with the respective translation product in the absence (lane 2 and 5) or presence (lane 3 and 6) of 10 mm 1,10 o - phenanthroline. the n1 and n2 subdomains of iep110 are both necessary for efficient envelope targeting and insertion. (a and b) amino acids 150269 of iep110 were fused to the presequence of either iep110 or ssu, resulting in tp110 - 110n2 and tpssu-110n2, respectively. s - labeled translation product was incubated with intact pea chloroplasts (equivalent to 30 g chl), and the localization of processed, mature 110n2 was tested by chloroplast subfractionation before (lanes 2 and 3) or after treatment with the proteases thermolysin (lanes 4 and 5) or trypsin (lanes 6 and 7). chloroplasts were subfractionated into a soluble stroma phase (lanes 2, 4, and 6) and a membrane fraction (lanes 3, 5, and 7) either before (lanes 2 and 3) or after treatment of the organelles with the proteases thermolysin (lanes 4 and 5) or trypsin (lanes 6 and 7). (d) the tpssu-110n - mssu translation product is imported into the chloroplasts under standard conditions. 110n - mssu can be translocated into the inner envelope membrane via a soluble stromal intermediate. (a) s - labeled tpssu-110n - mssu translation was incubated with intact chloroplasts (equivalent to 200 g chl in 500 l reaction volume) at 0c to allow binding but not import. after 5 min, the chloroplasts were reisolated through a 40% percoll cushion, washed, and resuspended in fresh 25c tempered import buffer. aliquots (equivalent to 30 g chl) were taken at the time intervals indicated, and the translocation reaction was halted by the addition of ice - cold import buffer. (b) quantification of the fluorogram shown in a. different exposures of the x - ray film were quantified using a laser densitometer. the sum of radioactivity found in either the soluble or membrane fraction at 0.5 min was set to 100%. | the chloroplastic inner envelope protein of 110 kd (iep110) is part of the protein import machinery in the pea. different hybrid proteins were constructed to assess the import and sorting pathway of iep110. the iep110 precursor (piep110) uses the general import pathway into chloroplasts, as shown by the mutual exchange of presequences with the precursor of the small subunit of ribulose-1,5-bisphosphate carboxylase (pssu). sorting information to the chloroplastic inner envelope is contained in an nh2-proximal part of mature iep110 (110n). the nh2-terminus serves to anchor the protein into the membrane. large cooh - terminal portions of this protein (8090 kd) are exposed to the intermembrane space in situ. successful sorting and integration of iep110 and the derived constructs into the inner envelope are demonstrated by the inaccessability of processed mature protein to the protease thermolysin but accessibility to trypsin, i.e., the imported protein is exposed to the intermembrane space. a hybrid protein consisting of the transit sequence of ssu, the nh2-proximal part of mature iep110, and mature ssu (tpssu-110n - mssu) is completely imported into the chloroplast stroma, from which it can be recovered as soluble, terminally processed 110nmssu. the soluble 110n - mssu then enters a reexport pathway, which results not only in the insertion of 110n - mssu into the inner envelope membrane, but also in the extrusion of large portions of the protein into the intermembrane space. we conclude that chloroplasts possess a protein reexport machinery for ieps in which soluble stromal components interact with a membrane - localized translocation machinery. |
despite considerable public health efforts to curtail obesity, the epidemic has progressed over the past three decades in the united states (us). epidemiological data from the most recent national health and examination survey (nhanes 2009 - 2010) indicated that 68.8% of american adults are overweight or obese (body mass index, bmi 25 kg / m). nearly half of this population has a bmi 30 kg / m, suggesting that about 36% or one - third of the us adult population is currently obese. while obesity has been linked to a number of chronic diseases, overwhelming epidemiological data indicate a positive correlation between bmi and bmd [16 ]. although the exact mechanisms underlying this observation are not fully understood, this protective effect could be attributed to increased mechanical load, imposed by a greater weight on weight - bearing bones as well as hormonal changes associated with obesity, for example, increased synthesis of estrogen and leptin by adipocytes. higher levels of estrogen, known to suppress osteoclastic bone resorption and stimulate osteoblastic bone formation, have been found in serum of obese postmenopausal women when compared to their normal weight counterparts. this fact is attributed to an increased peripheral production of estrone through increased aromatization of androstenedione by aromatase in the white adipose tissue [8, 9 ]. additionally, plasma leptin levels have been directly associated with the amount of fat mass. though leptin is primarily known to influence energy intake and expenditure, it has also been shown to be an important factor in the regulation of bone remodeling. in contrast to the putative protective effects of excess body weight on bmd, evidence challenging this relationship has recently emerged.. showed that in healthy adults greater fat mass negatively correlates with bmd after correction for the mechanical loading effect of body weight. in addition, blum. found that serum leptin is negatively associated with bmd in premenopausal women. further, ducy. observed that intracerebroventricular infusion of leptin reduced bone mass in ob / ob and wild - type mice, respectively. due to the increasing incidence and prevalence of obesity and the controversial findings in the literature about the relationship between bmi and bmd, the main purpose of this study was to investigate the effects of obesity on bone mass and quality in female zucker rats, the most commonly used rat model of genetic obesity. because postmenopausal women experience rapid bone loss and are prone to gaining excess body weight, we also investigated the effect of obesity on bmd in a rat model of postmenopausal bone loss. the animal protocol for this study was approved by the institutional animal care and use committee of the university of arkansas for medical sciences. six - week old leptin receptor - deficient female (lepr) zucker rats and their heterozygous lean controls (lepr) were sham - operated (lean - lepr, n = 6 ; obese - lepr, n = 6) or ovx (lean - lepr, n = 6 ; obese - lepr, n = 6) by harlan industries (indianapolis, in, usa) and housed in the animal facilities at the arkansas children 's hospital research institute. rats were housed in polycarbonate cages (2/cage) and had free access to water and a semipurified ain-93 g diet (harlan - teklad, madison, wi, usa) for 21 weeks. at 27 weeks, rats were sacrificed, and l4 vertebrae and tibiae were removed and cleaned of adhering tissue. l4 vertebrae were then scanned to determine bone mineral area (bma), bone mineral content (bmc), and bmd using dual energy x - ray absorptiometry (dxa ; qdr-4500a elite ; hologic, waltham, ma, usa) while tibiae were frozen at 20c for microstructural analysis. the microarchitectural trabecular bone structure of tibiae was evaluated using microcomputed tomography (ct40, scanco medical, switzerland). the tibia was scanned from the proximal growth plate in the distal direction (16 m / slice). this region included 350 images obtained from each tibia using 1024 1024 matrix resulting in an isotropic voxel resolution of 22 m. an integration time of 70 ms per projection was used, with a rotational step of 0.36 resulting in a total acquisition time of 150 min / sample. the volume of interest (voi) was selected as a region 25 slices away from the growth plate at the proximal end of the tibia to 125 slices. the three - dimensional (3d) images were also obtained for visualization and display. the trabecular bone morphometric parameters assessed with ct included the bone volume expressed as a percentage of total volume (bv / tv), trabecular number (tb.n), thickness (tb.th), and separation (tb.sp). nonmetric parameters included structure model index (smi) which is an indicator of plate - rod arrangement of the bone structure and connectivedensity (conn.d). a 2 2 (group by time) repeated measures analysis of variance (anova) was used to determine differences in body weight between groups and over time while one - way anova was used to determine group differences in bone parameters after treatment. in the event of a significant main effect or interaction, tukey - kramer post hoc data analyses were generated using ssps version 20.0 for windows (spss inc., chicago, il). initial and final body weights are shown in table 1. as expected, despite the similar initial body weights, ovx rats gained significantly more weight than sham rats. additionally, mean final body weight for obese - ovx zucker rats was significantly (p < 0.001) higher than in lean - ovx zucker rats (340 and 562 g, resp.). notably, the mean l4 vertebral bmd was approximately 11.5% lower in ovx rats than in the sham rats, irrespective of body weight (table 2), whereas the mean bmc of l4 vertebrae was only significantly higher in the obese - sham zucker rats compared to lean - ovx zucker rats (table 2). the 3d image analyses of the proximal tibia indicated that ovariectomy unfavorably altered trabecular microstructural parameters in both lean and obese groups (figure 1) with the exception of tb.th (figure 1(c)). when compared to lean - sham zucker rats, tb.th tended to be lower in the lean - ovx zucker rats (p = 0.06) and in the obese - sham zucker rats (p = 0.09) ; however, this parameter was only significantly (p = 0.005) lower in the obese - ovx group. although obesity and osteoporosis are two chronic conditions that have long been considered to be mutually exclusive, there is evidence that a complex relationship between the two exists. for decades, an array of epidemiological studies available have reported positive correlations between bmi and/or fat mass and bmd which led to the belief that excess body weight stimulates greater bone mass, strength, and quality primarily due to mechanical loading [12, 1517 ]. at the same time, several animal studies [1820 ] have indicated the detrimental effects of excess body weight on bone ; however, to our knowledge, only one of these studies has taken into consideration menopausal status while examining this relationship. therefore, the purpose of our study was to investigate the effects of obesity on bone considering the menopausal status of the rat. the results of the current investigation indicate that mean bmd of l4 vertebrae was not altered in lean and obese intact zucker rats whereas it was found to be significantly lower in lean and obese - ovx zucker rats. these observations are partially corroborated by the findings of picherit at al. who observed that 6-month lean - ovx zucker rats have lower femoral bmd than lean - sham zucker rats ; however, the effect of ovariectomy on femoral bmd of obese zucker rats was not assessed. they also found the femoral bmd of obese zucker rats to be distinctly lower than that of lean zucker rats but similar to that of lean - ovx zucker rats, a discrepant result from our observations. although unexpected, in the current study, obesity did not exacerbate or attenuate the effects of ovariectomy on bmd. though the number of studies addressing the relationship between obesity and bone mass in ovx - zucker rats is limited, this relationship has been explored to a greater extent in c57bl/6j mice. for instance, nez. reported that overweight - ovx female c57bl/6j mice had higher whole body bmd when compared to lean - ovx mice. in contrast, they found that very obese - ovx mice (55% body fat) had markedly lower bmd than the overweight - ovx mice. their findings suggest that a threshold may exist in order for body weight to exert protective effects on bone. hence, we postulate that there may be a u - shaped relationship between body weight and bone, though this needs further investigation. in addition, other investigators have reported that obesity induced by a high - fat diet significantly decreased femur and lumbar bmd in male c57bl/6j mice. in contrast, there are reports indicating that obesity induced by a high - fat diet increased spine bmd but had no effect on whole body bmd in male mice [22, 23 ]. in terms of human studies, independent reports have indicated that high bmi was positively associated with greater whole - body and spine bmd in postmenopausal women [24, 25 ]. case - control and retrospective studies have also demonstrated that obese postmenopausal women have greater femoral and lumbar spine bmd than nonobese postmenopausal women. the findings of a cross - sectional study by castro. reported that high bmi correlates with decreases and increases, by units, in the odds of low bmd in white and african - american women, respectively, suggesting a possible racial discrepancy. for instance, a study by zhao. reported that greater fat mass negatively correlates with bmd after correction for the mechanical loading effects of body weight in healthy adults. altogether, much of the data presented from animal as well as human studies are inconclusive with respect to the effect of obesity on bmd. with respect to bone trabecular properties, our results show that obesity did not affect any of the bone microstructural parameters in intact rats. our findings also indicate that bone microstructural parameters were unfavorably affected by ovariectomy in lean and obese zucker rats in comparison to those intact, with the exception of tb.th, which was preserved in lean - ovx zucker rats. although there is a paucity of studies reporting the effect of obesity on bone microstructural parameters in ovx zucker rats, observations similar to ours for instance, the preservation of tb.th observed in the lean - ovx rats is in agreement with the findings of yoshida. who reported that bone loss in ovx - wistar rats interestingly, tb.th was found to be markedly lower in obese - ovx zucker rats when compared to the other groups suggesting that obesity has a negative effect on bone. in contrast to our findings, in male c57bl/6j mice, obesity induced by a high - fat diet did not affect tb.th but negatively altered all other microstructural parameters [19, 23 ]. these mouse studies examined the bone microarchitecture of femurs and lumbar vertebrae, respectively ; yet in our study the tibiae were used. thus, the difference in bone specimens may explain the discrepancy in our findings as it has been demonstrated that rates of trabecular bone loss are higher in the lumbar vertebrae than in the tibiae. nonetheless, a preservation of tb.th has been also observed in women [29, 30 ]. particularly, the os des femmes de lyon (ofely) study reported that obese postmenopausal women had significantly greater tb.n, lower tb.sp, and similar tb.th at the distal tibia when compared to normal - weight women. therefore, it is imperative that future studies investigate the effect of obesity on specific bones in order to make relevant comparisons. the effects of ovariectomy on bone mass and microstructure in lean and obese zucker rats were anticipated as the 6-month - old ovx - rat is considered a rat model suitable to study postmenopausal bone loss. nonetheless, the validity of using obese - ovx zucker rats as a model of postmenopausal obesity remains unclear as these animals exhibit altered ovarian morphology, with decreased production of estrogen, and are not fertile. thus, one could argue that the obese intact zucker rat is not the ideal model of premenopause in comparisons involving lean zucker rats that exhibit 4-fold higher levels of estrogen than obese zucker rats. indeed, estrogen is a necessary factor for bone growth and development as well as a regulator of bone turnover in mature bones. the fact that bone mass did not differ between obese - ovx and intact zucker rats and their lean controls implicates adipose tissue as the source for the estrogen necessary to maintain bone mass in the absence of ovarian estrogen. it has been shown that most estrogen in postmenopausal women is produced in peripheral adipose tissue by aromatization of androstenedione to estrone [7, 35 ], especially in obese and overweight women. [3538 ] demonstrated that the rate of conversion of androstenedione to estrone is increased by obesity. another factor associated with obesity is low levels of sex hormone binding globulin which results in increased bioavailable estradiol. circulating leptin increases as body weight and fat mass increase [40, 41 ] which may be another contributing factor for the maintenance of bone mass in obese - ovx zucker rats observed in this study. previous data suggest that serum leptin may play an important role in bone remodeling [11, 42 ]. levels of leptin, which is a protein coded by the ob / ob gene and secreted by adipocytes, are increased in response to elevated estrogen levels [43, 44 ]. aromatase activity contributes to increased estrogen synthesis in adipose tissue and may be an important factor in increasing leptin in obese zucker rats. this may partially explain why bone mass was not significantly different between obese - ovx and intact zucker rats and their respective lean controls. in fact, the literature supports this notion as leptin deficient mice have been shown to have impaired bone growth. in addition, administration of leptin to male mice has been shown to reduce bone fragility as denoted by increased work to failure and displacement in comparison to their controls. cortical bone microstructural parameters as well as dynamic histomorphometry data and biomechanical properties were not evaluated. future studies should assess these parameters as they may lead to a better understanding of the effects of obesity on bone in ovx zucker rats. even though lepr rats are known to exhibit the obesity phenotype around 4 - 5 weeks of age and in the present study these rats were obese for approximately 22 weeks, we did not longitudinally examine weight and bone parameters which should be done in the future. body composition (e.g., lean and fat mass) could provide additional insight into the relationship between obesity and bone in ovx zucker rats. lastly, a larger sample size may have helped to detect significant differences among many of the parameters of interest. however, a sample size of six rats per group was used per other rat models as there were no similar studies available at the time of conducting the present study. future studies should be conducted in this rat model using a larger sample size to enable the detection of significant differences for the parameters of interest. in summary, the findings of animal and human studies regarding the effects of obesity on bone health are inconsistent and may be attributed to several factors. first, the majority of human studies report findings that are primarily derived from correlational analyses as opposed to controlled trials, thereby precluding a cause - and - effect relationship from being established. second, existing animal studies vary in the use of species and strains as well as age, gender, and estrogenic environment. third, various means of inducing obesity, for example, through genetic manipulation or high - fat diet, may influence the bone outcomes assessed. therefore, the relationship between obesity and bone health can not be established at this time. collectively, aside from the adverse effects on tb.th, the findings of the present study do not show a directional relationship between obesity and bone health in zucker rats. | obesity and osteoporosis are two chronic conditions that have been increasing in prevalence. despite prior data supporting the positive relationship between body weight and bone mineral density (bmd), recent findings show excess body weight to be detrimental to bone mass, strength, and quality. to evaluate whether obesity would further exacerbate the effects of ovariectomy on bone, we examined the tibiae and fourth lumbar (l4) vertebrae from leptin receptor - deficient female (leprfa / fa) zucker rats and their heterozygous lean controls (leprfa/+) that were either sham - operated or ovariectomized (ovx). bmd of l4 vertebra was measured using dual - energy x - ray absorptiometry, and microcomputed tomography was used to assess the microstructural properties of the tibiae. ovariectomy significantly (p < 0.001) decreased the bmd of l4 vertebrae in lean and obese zucker rats. lower trabecular number and greater trabecular separation (p < 0.001) were also observed in the tibiae of lean- and obese - ovx rats when compared to sham rats. however, only the obese - ovx rats had lower trabecular thickness (tb.th) (p < 0.005) than the other groups. these findings demonstrated that ovarian hormone deficiency adversely affected bone mass and quality in lean and obese rats while obesity only affected tb.th in ovx - female zucker rats. |
these tumors are rarely associated with clinical manifestations ; therefore, they are usually discovered incidentally at the time of surgery, frequently in association with acute appendicitis. its clinical significance lies in the possible rupture and consequent spillage of mucin into the peritoneal cavity, leading to pseudomyxoma peritonei. even if laparoscopy has been successfully used to perform appendectomy, some concerns exist regarding its use in dealing with mucinous secreting lesions because of possible spillage of mucin during surgery. the role of laparoscopic resection in the management of appendix tumors is not well defined in the literature. we report the case of a large (10 cm 6 cm) low - grade appendiceal mucinous neoplasm, for which a formal right hemicolectomy was successfully performed using a laparoscopic approach. the patient was a 60-year - old doctor who was recently diagnosed with an appendicular tumor while being investigated for vague abdominal pain. pneumoperitoneum was achieved via a veress needle and intraabdominal pressure maintained at 12 mm hg. the patient was placed in the trendelenburg position with a left lateral tilt to facilitate the bowels to fall away from the right abdomen. five ports were placed in the upper abdomen : (1) 10-mm port 2 cm above the umbilicus ; (2) 5-mm port (right working hand) in the left midclavicular line ; (3) 5-mm port (left working hand) in the right iliac fossa ; (4) 10-mm port (for bowl retraction) in the epigastrium ; (5) 10-mm port in the hypogastrium. initially, with the telescope in the umbilical port, the lesion was identified as a large spherical tumor (figure 1). the telescope was now moved to the hypogastric port, a 5-mm harmonic shears was placed in the umbilical port, and an atraumatic grasper was placed in the right iliac fossa port. the grasper was used to gently probe the tumor, taking care not to grasp it or handle it. so the decision to perform a formal right hemicolectomy was made, and dissection was commenced by incising the visceral peritoneum adjacent to the ileocecal junction (figure 2). the dissection was now continued in the avascular facial plane of toldt (figure 3), visualizing and preserving the right ureter and gonadal vessels. the ileocolic, right colic, and right branch of the middle colic vessels were ligated with the ligasure (valleylab, usa) sealing device (figure 4). a 5-cm incision was made by enlarging the umbilical port and a wound protector applied to it. end - to - end ileocolic anastomosis was performed extracorporeally with 00 pds sutures in a single - layer fashion. orally, liquids were allowed on the second postoperative day (pod) and semisolids the next day. the drain tube was removed on the fourth pod, and the patient was discharged on the fifth pod. histopathology report was consistent with low - grade appendiceal mucinous neoplasm characterized by herniation of mucin into the muscularis propria, forming a diverticulum. the lesion was seen involving the base of the appendix, with no evidence of malignant cells or infiltrating pattern (figure 5). the patient was followed up for 24 months and has had no recurrence so far. histopathology : herniation of mucin into the muscularis propria, with no evidence of malignant cells or infiltrative pattern possibility of low - grade appendiceal neoplasm. they are found in less than 2% of appendectomies and are associated with appendiceal perforation in 20% of cases. quite often, other neoplasia like adenocarcinoma of the colon and ovaries coexist, so an intraoperative exploration of the whole abdomen and colonoscopy, especially in patients over 60 years of age, is desirable. the 5-year survival rate is 100% in cases of benign mucocele and about 45% in malignant cases. the existing terminology on appendiceal tumors do not provide an accurate description, underplaying the considerably high mortality and morbidity associated with these lesions. so the term low - grade appendiceal mucinous neoplasm was coined by misdraji at harvard medical school to provide a more realistic perspective. however, a right hemicolectomy should be considered for patients with malignant mucinous lesions or if a benign tumor involves the base of the appendix. the latter was the case in our patient making it impossible to achieve a tumor - free margin at surgery, so we proceeded with a formal laparoscopic right hemicolectomy. also, if a mucocele is more than 2 cm in size, it is more likely to be neoplastic. in our patient, the indications for the laparoscopic approach to the resection of these tumors have not yet been established definitively. some investigators have argued that laparos - copy does not increase the risk of local recurrence or metastasis after tumor resection over that associated with open surgery. as evidence of the benefits associated with laparoscopic appendectomy accumulates, an increasing number of resections for appendiceal tumors are being performed via laparoscopy. despite growing evidence favoring the laparoscopic approach, gonzales reported a case of laparoscopic mucocele resection that was followed by early peritoneal progression, forcing them to conclude that this entity was a contraindication to laparoscopic resection. we have published our series of 8 patients with appendiceal mucocele who successfully underwent laparoscopic resection at our institute. data indicate that whether the resection of appendiceal carcinoids is accomplished via laparoscopy or the open approach, long - term results are similar. however, only a few cases of appendiceal tumors not of the carcinoid type have been resected thus far by the laparoscopic approach. even though our patient had no recurrence or spillage, experience with the laparoscopic resection of appendiceal neoplasms is still not sufficient, and therefore it may be wise to use the open approach in centers with little laparoscopic experience. as the technique of laparoscopic appendectomy evolves, the feasibility of resecting appendiceal neoplasms via this approach should also be assessed. data from some studies indicate that laparoscopic appendectomy for the management of appendix neoplasms is associated with long - term results comparable to those obtained with open appendectomy. our case report adds to the existing data regarding the safety of laparoscopy for cases of appendiceal neoplasm. the wound protector that we applied will prevent port - site seeding. currently, opinion among surgeons regarding the laparoscopic treatment of appendiceal tumors stands divided. we are of the opinion that laparoscopic surgery can be used for appendiceal tumors as well, provided certain precautions are taken. we believe that the laparoscopic approach is safe if performed by an experienced surgeon. also, the benefits of minimally invasive surgery like reduced hospital stay, less pain, better cosmesis, and early return to work can also be utilized. conversion to laparotomy should be considered only if the lesion is traumatically grasped and ruptures in the peritoneal cavity. | tumors of the appendix are rare entities causing mucoceles. the majority of them are discovered incidentally during investigation for other conditions. laparoscopic surgery for appendiceal tumors is still controversial, as inadvertent rupture of the lesion due to improper handling will cause pseudomyxoma peritonei. the patient was incidentally discovered to have an appendiceal tumor and referred to us for laparoscopy. because the tumor involved the entire appendix, a laparoscopic right hemicolectomy was performed without directly handling the tumor. postoperative recovery was uneventful. pathological diagnosis was low - grade appendiceal mucinous neoplasm. the safety of laparoscopic appendectomy for the management of incidentally discovered appendiceal tumors has not yet been established. several reports in the literature support both laparoscopic and open surgery. the main concerns to be addressed are the adequacy of resection and intraperitoneal rupture of the tumor. our patient successfully underwent laparoscopic surgery without any complications. a formal right hemicolectomy was performed because the tumor involved the entire appendix. we now think laparoscopic surgery for appendiceal tumors is safe, feasible, and even may be beneficial. |
a prospective observational cohort study of patients presenting for home carealmost 1/5 of patients with advanced cancers suffer from pressure ulcersnone of the patients enrolled had a new pressure ulcer during home carepressure ulcer resolved completely with care in 40% of the patientsthis care could be provided at a median cost of rs. a prospective observational cohort study of patients presenting for home care almost 1/5 of patients with advanced cancers suffer from pressure ulcers none of the patients enrolled had a new pressure ulcer during home care pressure ulcer resolved completely with care in 40% of the patients this care could be provided at a median cost of rs. the national pressure ulcer advisory panel (npuap) defines pressure ulcers (pu) as a form of localized tissue injury that develop as a result of pressure or pressure in combination with friction / shear. hendrichova., from italy had found a rate of 22.9% in cancer patients treated at a palliative care unit. brink., found a prevalence rate of 10.5% in patients under home care for terminal cancers. dealey., estimated that the cost of treating pus in uk ranged between 1,21414,108 depending on the severity of the ulcer. the healthcare system in india is overburdened and few facilities are available for providing end - of - life care. invariably, most of the care is delivered at home and caregivers are family members. the kerala model of palliative care depends on a network of trained volunteers and nurses who provide homecare services through regular visits. in addition to developing a trained cadre of community - based care providers, several innovative methods are used to bring down the cost of care. our homecare service consists of trained palliative care nurses who conduct regular homecare visits for terminal cancer patients supported by a trained palliative care physician. for logistic reasons, while there are few publications on the burden of pus in indian patients in hospital settings, we could not find any data in patients suffering from cancer. in the present paper, we present data on prevalence of pu, the effectiveness in terms of healing, duration of persistence as well as the expenditure incurred for this care in a cohort of homecare patients with cancer included for a prospective study. after obtaining irb approval, patients presenting for home care were included in this prospective observational study (ctri number : ctri/2014/03/004477). patients were selected for homecare service provided they resided within a distance of 35 km from the center. patients were followed up at fortnightly interval till death. as a part of the homecare process, a trained nurse would visit the house of the patient and provide care and education. visits were conducted as per a preplanned route plan at fortnightly intervals. during each visit, the data collected included the size, location, and stage of pu if any. all pus were staged by the nurse using the npuap staging scheme. in patients without pus, caregivers were trained in the importance of regular postural changes, maintaining hygiene and nutrition. during each visit, the trained nurse assessed if any pus had developed in the interim. in patients with pre - existing pus, similar in addition, simple saline dressings were instituted using cloth strips cut from cotton dhotis. these strips were boiled in a steamer that is meant for steaming pancakes (idlis) for at least 20 minutes. instead of using commercially available normal saline, normal drinking water mixed with 2 tsp salt per liter of water would be boiled for 5 minutes and used for cleansing. for patients with foul smelling / malodorous wounds metronidazole tablets the cost of medications and other consumables supplied to the patient as well as the cost of staff and salary was borne by the hospital. the fixed cost per visit which included payment for the nurses salary, driver salary, and car fuel costs worked out to be rs. the salary paid per hour was derived from the monthly salary for the driver and nurse. the total costs of consumable items like medications given to each patient were derived from the medicine records maintained prospectively for each visit. the cost of metronidazole tablets and sticking tapes used in patients with pu was included in the wound care costs. the total costs of visits were calculated by adding the total expense per visit with the expenses incurred in consumable items like medicines. the total cost was divided by the total number of days in home care to obtain the cost per day for each patient. data on demographic variables, cancer site, stage, treatment received, and performance status at first visit was recorded on a datasheet. median and interquartile range were calculated for continuous variables, while frequencies were calculated for categorical variables. logistic regression analysis was conducted to find out the influence of various prognostic factors on the healing of pus. duration of persistence of pus was estimated from the date it was noticed first till the date it was healed. in patients with pu at the first visit, the date of first visit was taken as the start date. patients were censored at the date of death if the ulcer was not completely healed by then. for purpose of analysis, cancers with less than 10 patients were grouped together as a single category. table 1 shows the demographic profile of the patient population in the study. out of these, 27 (25%) patients were unfit for any chemotherapy, surgery, or radiotherapy and were referred for palliative care. in these patients, 23 had progressive disease after receiving treatment for their cancer outside the hospital while 4 were not treated in view of their advanced age and performance status. the sociodemographic and disease related profile of the 108 patients included in the study nineteen (17.6%) patients had received curative intent treatment with surgery or radiotherapy while 62 (57.4%) had received palliative treatment prior to registration for home care. in the 62 patients treated with palliative intent after diagnosis, palliative chemotherapy had been delivered in 25 patients while the rest (n = 37) received palliative radiotherapy. the distribution of pus as per prognostic categories in 21 patients with pus, complete healing of the pus was seen in 9 (42.9%) while in another 5 (23.8%), reduction in the stage was observed. in 5 (23.8%) patients, the stage of pu did not change while in 2 (9.5%) patients, an increase in stage was noted. figure 1 is a waterfall plot showing the change in the stage of pus between the first and the last homecare visit. both the 2 patients who had an increase in the stage of pu during homecare visits had an initial stage 1 pu that subsequently increased to stage 2 before they died. waterfall plot showing the extent of change in the stage of pu between the 1st and last homecare visit. patients with complete resolution of pu are depicted by hatched bars while solid bars represent patients where pus did not resolve completely. as can be seen none of the patients with grade 34 pressure ulcers had a complete resolution. however, in these patients, a decrease in stage was observed in 3 patients while in other 3 the stage remained stable table 3 shows the influence of various factors on the healing of pus. on logistic regression analysis financial status, paralysis, and performance status significantly influenced the healing pus. influence of various prognostic factors on the resolution of pus during home care median estimated duration of persistence of any pu in these 21 patients was 56 days (95% ci : 0117 days) [figure 2 ]. the median duration of survival of patients with stage 12 pu was 75 days versus 37.5 days for stage 34 pu (p = 0.22, ns). in the 21 patients with pu, any pu was observed by the homecare team in a median of 3.5 visits (iqr : 2.54.5). in this same group, numbers at risk at each time point are shown below the graph the median total expenditure incurred in caring for the patients with pus was rs. 2323.40 (iqr : rs. 1878.402768.40) and the median daily expenditure was rs. this includes the cost of homecare visits where care for pu had to be provided as well as visits were pu care was not provided as the pu had healed. the total cost incurred by the hospital in caring for patients in the homecare services was rs. the expenditure incurred by the hospital in caring for the 21 patients with pu was rs. the present study showed that almost 20% patients with advanced cancer taken up for homecare services suffer from pu in our population. this figure is comparable to that reported by hendrichova., but higher than that reported by brink. this high prevalence of pu at presentation points to the need for sensitization of oncologists towards this common but unappreciated problem faced by patients with terminal cancers. poor performance status and presence of paralysis predicted an increased risk of presenting with pus in this cohort of patients [table 2 ]. the causes behind development of pu is poorly understood and is not a result of a single factor. in a recent systematic review coleman., have identified three major domains that predict an increased risk of pu development. these domains are mobility / activity, skin perfusion (e. g., diabetes) and skin condition, particularly existence of a stage i pu, as important predictors of development of pu. due to the small number of patients with pu, only the single domain of reduced mobility / activity (in form of paralysis and performance status) emerged as significant. the limited lifespan of these patients also influenced this as parameters related to limited skin perfusion and existing pu are likely to be significant only with longer duration of follow - up. in the present study, 40% of the pus had completely healed before the last homecare visit. the median time taken for complete healing of pressure ulcers was 56 days from the date of registration in homecare services. this is comparable to the results reported by mcnees., where 44% of pressure ulcers and wounds had healed in cancer patients and the median time taken for healing was 55 days (49 days)., in their study only 10% of pressure wounds had healed prior to the death of the patient. in contrast to stage i and ii pus, majority of which healed in the present study, none of the stage iii - iv pu healed completely. however, 50% of these patients had a reduction in stage and none had a worsening in the stage. brandeis., have shown that with good nursing care majority of the pressure ulcers heal within a period of 1 year. in the present cohort, the limited lifespan of the patients with advanced pressure ulcers (median survival with stage 34 ulcer : 37.5 days only) prevented complete healing., in patients surviving less than 180 days (6 months), none of stage iv pus healed completely. in fact the authors hypothesized that such pus may represent a reflection of the underlying disease burden and be a part of the spectrum of the overall co - morbidity preceding death in such patients. the healing of the pus in the present study was influenced by the baseline performance status and presence of paralysis. while patients with poorer performance status had a poorer chance of healing of pu, paradoxically in all three patients with paralysis the ps healed. two patients had a stage i pu and one had a stage ii pu all three of which had healed completely by the end of the homecare visits. this finding is likely to be due to chance because of the small number of patients. the model of homecare service as delivered through our center is a derived from the kerala model of home - based palliative care services. an advisory model is adopted and patient 's relatives are entrusted with providing nursing care without relying on hiring specialized nurses. this model was borne out of necessity, as there is a triple combination of high patient load, lack of trained nursing manpower, and poor financial status in our part of the world. in developed nations, the cost of caring for pus alone can exceed $ 2 billion (~1% of total healthcare budget) as reported by severens. such expenditure is not possible in our country where the total healthcare budget is only $ 6 billion. additionally, the nature of family ties in our part of the world is such that usually want to take care and nurse the sick patient. the role of the homecare team is to educate and empower the caregiver in the family by teaching them simple and cost effective methods of caring for the patients, as well as allaying their apprehensions and misgivings. however in most such palliative homecare services, trained physicians are not available. as a result in the event of any untoward event relatives are forced to turn to local hospitals where patients may not have been primarily treated for their cancer. the present homecare team on the other hand has a close communication with the palliative care specialist as well as other oncologists in the hospital. as a result, in the event of any emergency or sudden problem, thus both the patients as well as the caregivers are assured of continuity of care. the present study is thefirst study which reports the prevalence and outcomes of pus in terminal cancer patients managed using the kerala model of palliative home care. the strengths of this study are its prospective nature wherein detailed observation of the patients condition was made by a trained palliative care team. the low cost of the present model is evident in the fact that the total expenditure for caring of 21 patients with pu was rs. this compares very favorably to the cost incurred for caring and preventing pu in a long term care facility in 539 patients as reported by xakellis. due to resource limitations, we could only include patients who resided within a distance of 35 km from the institute. given the hybrid nature of our homecare model, the outcome data can not be readily generalized to patients referred to other homecare services in india. it is also unknown if the effectiveness of care as used in this model compares favorably to the more established and expensive methods of wound care. the costs reported are direct costs incurred by the hospital as indirect costs incurred by the patients relatives in caring for the patients with pu were not recorded. the actual indirect cost of such a care model needs to be further studied using prospective studies. in this study,, a recent cochrane review has also shown that there is little evidence that use of structured pu risk assessment tool is useful in reducing the risk of developing pu. our prospective study demonstrates that there is a high prevalence of pus in patients referred to home care with terminal cancers. the hybrid model of homecare service delivery, as adopted in the present study, was able to prevent new pus from developing in the patient population. in addition, complete healing was seen in 40% of the patients, with an average expenditure of rs. | aim : to report the prevalence and outcomes of pressure ulcers (pu) seen in a cohort of cancer patients requiring home - based palliative care.materials and methods : all patients referred for home care were eligible for this prospective observational study, provided they were living within a distance of 35 km from the institute and gave informed consent. during each visit, caregivers were trained and educated for providing nursing care for the patient. dressing material for pu care was provided to all patients free of cost and care methods were demonstrated. factors influencing the occurrence and healing of pus were analyzed using logistic regression. duration for healing of pu was calculated using the kaplan meier method. p < 0.05 are taken as significant.results:twenty-one of 108 (19.4%) enrolled patients had pu at the start of homecare services. none of the patients developed new pu during the course of home care. complete healing of pu was seen in 9 (42.9%) patients. the median duration for healing of pu was found to be 56 days. median expenditure incurred in patients with pu was rs. 2323.40 with a median daily expenditure of rs. 77.56.conclusions:the present model of homecare service delivery was found to be effective in the prevention and management of pus. the high prevalence of pu in this cohort indicates a need for greater awareness for this complication.clinical trial registry number : ctri/2014/03/004477 |
the spherical aberration of the cornea is positive and that of the lens is negative in the young, healthy eye, and these differences have a compensatory relationship [1, 2 ]. decreased optical quality occurs in the aging eye as the spherical aberration of the lens becomes gradually positive and thus loses its ability to compensate for the corneal aberration, which changes little with increasing age [15 ]. conventional spherical intraocular lenses (iols) act as an aging lens in which positive spherical aberration can not compensate for the corneal aberration. aspheric iols can decrease the total amount of ocular spherical aberration after cataract surgery due to their introduction of negative spherical aberration. it has been shown that aspheric aberration - correcting iols effectively reduce ocular aberration and improve contrast sensitivity in patients with age - related cataracts [615 ]. however, little is known about the safety and effectiveness of aspheric iols in patients with extreme myopia. therefore, we performed the current study to evaluate the clinical effects of aspheric iol implantation in cataract patients with extreme myopia by comparing the objective and subjective visual quality achieved with that achieved in nonextreme myopic eyes. we chose the mc x11 asp lens (humanoptics ag) as our experimental iol because it is currently the only aspheric iol with a negative power. the mc x11 asp lens is a one - piece hydrophilic acrylic iol with a prolate posterior surface that introduces negative spherical aberration to the ocular system. the optic diameter varies from 5.5 mm to 7.0 mm depending on the power of the iol. iols with a power of 18.0 diopter or less have an optic diameter of 7.0 mm. this prospective study included 33 eyes of 22 cataract patients (12 males and 10 females) who were scheduled to undergo phacoemulsification and iol implantation surgery between june 2008 and march 2009 at the eye & ent hospital, fudan university, china. exclusion criteria included a history of previous ocular surgery, ocular disorders other than cataract, myopia, or macular degeneration, and patient refusal or inability to maintain followup. patients were divided into two groups according to their ocular axial length. those with an axial length longer than 28.0 mm were included in the extreme myopia group, and the others were included in the nonextreme myopia group. the study was approved by the ethics committee of eye & ent hospital, fudan university. after topical anesthesia, a 2.2 mm superior clear corneal incision was made, and a 5.56.0 mm continuous curvilinear capsulorhexis was created. after hydrodissection, endocapsular phacoemulsification of the nucleus and cortical aspiration were performed using the intrepid micro - coaxial system on the infiniti (alcon laboratories inc.). preoperative measurements included visual acuity, intraocular pressure, axial length, and corneal endothelial cell density. at 1 day, 3 days, 2 weeks, and 1 month after surgery, visual acuity and slit - lamp examination were performed. six months postoperatively, visual acuity, refraction, contrast sensitivity, wavefront aberration, and subjective visual quality were assessed. complications such as posterior capsule opacification (pco) and retinal detachment were recorded at the last follow - up visit. subjective visual quality was evaluated using the self - administered edition of the national eye institute visual functioning questionnaire-25 (nei vfq-25). this 25-item questionnaire was designed to assess vision - related quality of life (vrql). it includes one general health rating question and 11 vision - targeted subscales as listed in table 2., the answer was converted to a 0-to-100-point score according to the manual, with higher scores representing better vrql. contrast sensitivity was measured using the contrast glare tester cgt-1000 (takaci) under mesopic illumination (10 cd / m) at a 350 mm testing distance. contrast sensitivity was defined as the reciprocal of the contrast threshold, and this value was converted to log contrast sensitivity for statistical analysis. after mydriasis, high - order aberrations were measured with the hartmann - shack aberrometer (wasca analyzer, carl zeiss meditec). three consecutive measurements were performed on each eye. the lateral coma (z3), vertical coma (z3), and spherical aberration (z4) as well as the root mean square (rms) values of the total high - order aberrations and 3rd - order to 7th - order aberrations over a 6.0 mm pupil diameter were automatically calculated by the aberrometer. independent t - test was used to compare demographic data, questionnaire scores, contrast sensitivity, and wavefront aberrations between the two groups. logarithm of the minimum angle of resolution (log mar) visual acuity values were tested by the wilcoxon rank - sum test. comparison of snellen visual acuity before and after surgery was performed using the cmh chi - square test. however, 7 eyes (38.9%) in the extreme myopia group had preexisting maculopathy before surgery, including 6 eyes with degenerative myopic maculopathy and 1 eye with macular schisis. six months after surgery, 77.8% of eyes in the extreme myopia group achieved a bcva of 20/40 or better, including 22.2% of eyes with 20/25 or better. four eyes demonstrated poor vision of less than 20/60 due to severe macular degeneration or macular schisis. in the nonextreme myopia group, 86.7% of eyes achieved a bcva of 20/40 or better, including 80.0% of eyes with 20/25 or better. the postoperative bcva of both groups was significantly better than the respective preoperative bcva values (= 16.36, p = 0.0001 ; = 20.94, p = 0.0000), and the nonextreme myopia group performed significantly better than the extreme myopia group (= 5.98, p = 0.0144). however, evaluation of the vfq-25 subscale scores revealed that the nonextreme myopia group performed significantly better than the extreme myopia group in terms of mental health and dependency. data related to driving were not analyzed, because none of the patients in the extreme myopia group and only four patients in nonextreme myopia group drove. as illustrated in figure 2(a), contrast sensitivity without glare did not differ between the groups at each spatial frequency. however, patients in the nonextreme myopia group showed better contrast sensitivity with glare at intermediate frequencies (visual angle of 2.5 degrees, p = 0.0277 and 1.6 degrees, p = 0.0181) (figure 2(b)). for a 6 mm pupil, the average spherical aberration (z4) was 0.03 0.11 m in the extreme myopia group and 0.07 0.07 m in the nonextreme myopia group, and total high - order aberrations were 0.50 0.17 m and 0.46 0.15 m, respectively. there were no significant differences in lateral coma, vertical coma, spherical aberration, total high - order aberrations, or 3rd - order to 7th - order aberrations (figure 3). one patient complained of glare in one eye (5.6%) in the extreme myopia group, and three eyes (20%) were associated with complaints of glare in the nonextreme myopia group, which did not represent a statistically significant difference (p = 0.340). the average follow - up period was 6.94 1.47 months (range 6 to 10) in the extreme myopia group and 6.60 1.59 months (range 6 to 12) in the nonextreme myopia group. at the last followup, two eyes in each group (11.1% and 13.3%, resp.) had moderate pco but did not require further treatment. one eye in the extreme myopia group developed capsular block syndrome, and the eye achieved a final visual acuity of 20/30 following anterior capsulotomy. it is well known that myopia is more common in asia than in america, europe, and africa with a prevalence of 32.3% in the urban adult chinese population reported by the latest epidemiological study published in 2009. high myopia prevalence also varies geographically, ranging from 1.7% to 3.3% in europe, while it affects up to 24% of university students in south - east asia. in this study, we carried out phacoemulsification and aspheric iol implantation with low or negative power on cataract patients with extreme myopia. we report the visual performance of aspheric iols in terms of functional vision in cataract eyes with extreme myopia in comparison to that achieved in patients with nonextreme myopia. our results show that aspheric iol implantation provided good visual outcomes in most eyes with extreme myopia, although some patients with extreme myopia had relatively worse retinal status than nonmyopia patients. when the seven eyes with maculopathy in the extreme myopia group were excluded from the data analysis, postoperative visual outcomes were similar between the two groups (= 1.45, p = 0.2288). for the seven excluded eyes, visual acuity improved after surgery anyway : one improved from hand moving to 20/400, one improved from 20/2000 to 20/250, and the other 5 improved 2 to 8 lines (snellen chart). in these patients, after objective visual acuity measurements, we assessed the subjective visual quality of the patients using the nei vfq-25. this questionnaire was designed to capture the impact of visual problems on physical functioning, emotional well - being, and social functioning. it has been widely used to evaluate health - related quality of life in patients with various eye diseases and treatments [1925 ]. the score from the extreme myopia group was similar to that reported by lin., who implanted the aspheric iq iol (sn60wf, alcon laboratories inc., interestingly, although the nonextreme myopia group had better postoperative bcva in the present study, the two groups reported similar subscale scores for near and distance activities ; that is, the patients ' perception of their visual function was similar. this might be attributed to the preoperative visual status of the patients with extreme myopia who always had poor visual function. therefore, the removal of the cataract along with the correction of the refractive errors likely resulted in a high level of patient satisfaction in terms of visual outcome. however, the subscale scores of mental health and dependency were significantly lower in this group, suggesting that these patients worried more about their eyesight and that their quality of life was more affected by vision., we found that patients with nonextreme myopia had better contrast sensitivity at intermediate spatial frequencies under glare conditions. these data are in agreement with stoimenova 's findings, which showed that myopes exhibited reduced sensitivity to contrast in comparison to emmetropes and that contrast sensitivity decreased with an increasing degree of myopia. this difference may contribute to the aberrations of the myopic eyes or functional / morphologic changes in the retina of myopic eyes. we also compared high - order aberrations between the groups and found that postoperative ocular spherical aberration (z4) was near zero in the two groups, which fulfilled the aim of compensating the corneal spherical aberration with an iol. the total effect of all monochromatic optical aberrations represents the optical quality of the eye. because the spherical and cylindrical refractive errors were fully corrected and high - order aberrations were similar between groups, the optical quality of the ocular system in the extreme myopia group was as good as that in the nonextreme myopia group. however, the extreme myopia group showed worse visual acuity and contrast sensitivity, mainly because of the poor retinal status. in the absence of macular degeneration, the eyes with extreme myopia would have achieved visual acuity as good as that of eyes with nonextreme myopia. glare disturbance occurred in 5.6% of patients in the extreme - myopia group and 20% of patients in the nonextreme myopia group, and this difference was consistent with the results of previous studies. franchini reported that glare occurred in 20% of patients who received the aspheric tecnis z9000 iol (abbott laboratories). in the study by johansson., 21.1% of patients who received an akreos adapt ao iol (bausch & lomb laboratories inc.) in one eye and a tecnis z9000 iol in the other eye experienced glare. in the current study, a possible cause may be that the macular disorder of some of the eyes was so severe that the patients could not detect the glare. in terms of the pco and retinal detachment the aspheric iol used in this study was the mc x11 asp, which features a large optic diameter (7.0 mm) for middle to low iol powers. it has been shown that greater optic diameter can reduce postoperative glare [30, 31 ]. larger optic diameter can also facilitate postoperative peripheral retinal examination and treatment, because eyes with high myopia are at high risk of lattice degenerations, retinal holes and tears, and retinal detachment. because of the larger optic diameter, a larger capsulorhexis of 6.0 to 6.5 mm was required. one patient developed capsular block syndrome, which may have been caused by a relatively small capsulorhexis opening. in conclusion, aspheric iols can provide good visual outcomes for cataract patients with extreme myopia. also, preoperative evaluation of the severity of maculopathy is very important and should be carefully performed in eyes of patients with extreme myopia before surgery. | objective. to evaluate the postoperative visual quality of cataract patients with extreme myopia after implantation of aspheric intraocular lenses (iols). methods. thirty - three eyes were enrolled in this prospectivestudy. eighteen eyes with an axial length longer than 28 mm were included in the extreme myopia group, and the other 15 eyes were included in the nonextreme myopia group. phacoemulsification and aspheric iol implantation were performed. six months after cataract surgery, best - corrected visual acuity (bcva), contrast sensitivity, and wavefront aberrations were measured, and subjective visual quality was assessed. results. the bcva improved significantly after surgery for both groups, and patients in the nonextreme myopia group achieved better postoperative bcva due to better retinal status of the eyes. the evaluation of contrast sensitivity without glare was the same in both groups, whereas patients in the nonextreme myopia group performed better at intermediate spatial frequencies under glare conditions. the two groups did not show a significant difference in high - order aberrations. with regard to subjective visual quality, the composite scores of both groups did not differ significantly. conclusions. aspheric iols provided good visual outcomes in cataract patients with extreme myopia. these patients should undergo careful evaluation to determine the maculopathy severity level before surgery. |
chronic kidney disease (ckd) is a major cause of morbidity and mortality in mexico. it has been estimated that 8% of the mexican population has an estimated glomerular filtration rate (egfr) 126 mg / dl. serum creatinine was used to determine the egfr using the modification of diet in renal diseases study equation ; participants were classified as having ckd based on the presence or absence of egfr 126 mg / dl ; 3.5% of homeless patients knew they were hypertensive but 31% had systolic blood pressure 140 mm hg or diastolic blood pressure 90 mm hg, similar to the general population but lower than the poor jalisco population (31.0% vs. 62%, p=0.0001). the prevalence of obesity among homeless participants was lower than in the general and poor jalisco populations (17.6% vs. 31% and 43%, respectively, p=0.0001). ckd, as defined by egfr<60 ml / min per 1.73 m, was more prevalent among the homeless than in the poor jalisco population (22.4% vs. 15.8%, p=0.0001) ; 16.5% had stage 3, 4.3% stage 4, and 1.2% stage 5 ckd. homeless individuals with ckd were older (60.7914.86 vs. 47.5717.62 years, p=0001) and more diabetic (18.1 vs. 16.2, p=0.03) than those without ckd. obesity (23.4% vs. 16.0%, p=0.27) and hypertension (34.5% vs. 30.3%, p=0.62) were more prevalent in persons with ckd, but these differences were not statistically significant. unfortunately, results of urinalysis are not reported because the majority (95%) of individuals refused to submit a urine sample, arguing the risk of being tested for drugs. addictions were more prevalent among the homeless than in the general population (75.3% vs. 55.1%, p=0.0001) (table 2). homeless persons showed a lower prevalence of alcoholism (23.5% vs. 32.3%, p=0.002) than the general population, but tobacco smoking (34.6% vs. 21.5%, p=0.0001) and substance abuse (18% vs. 1.1%, p=0.0001) were more prevalent among the homeless. likewise, chronic viral infections such as hiv (4.5% vs. 0.3%, p=0.0001) and hcv (7.7% vs. 1.4%, p=0.0001) were also significantly higher among the homeless than in the general population. it is estimated that 8% of the adult mexican population has egfr < 60 ml / min per 1.73 m (ref.) and that the prevalence is as high as 15.8% among high - risk, poor populations. risk factors for ckd such as diabetes, hypertension, and obesity are highly prevalent in the mexican population. our results show a higher prevalence of ckd (22%) among the homeless compared with the report by amato (8%), and our own data in poor urban and rural jalisco populations (15.8%). since the prevalence of traditional ckd risk factors like diabetes and hypertension among the homeless was lower than among the urban and rural poor populations, additional factors could explain this difference. first, the higher prevalence of chronic viral infections and substance abuse among the homeless could have played a role in the development of chronic glomerular disease ; however, the lack of urine samples to test for protein and sediment did not allow us to assess this possibility. second, as homeless individuals have limited access to health care, the presence of ckd risk factors may go unnoticed, increasing the risk of developing ckd. also, homeless persons are less likely to be aware of their illnesses, and to comply with prescribed medications and therapy. as shown in our study, the majority of people with documented diabetes and hypertension were unaware of these conditions, and none had health insurance. finally, homeless patients are more likely to present late in the course of ckd, which might lead to more rapid loss of kidney function. as shown in our study, 14 (5.5%) of the screened individuals had ckd stages 4 and 5 and had not ever seen a nephrologist. although data were collected prospectively, they may not be generalizable to all homeless settings in other regions of mexico. second, participants who agreed to participate in screening delivered by the mobile clinic may not be representative of those who would participate in other types of screening programs. therefore, our results can not be used to draw conclusions about the overall prevalence of ckd in homeless individuals in mexico. third, although the refusal to provide urine samples did not allow us to test for protein and hematuria, our results suggest that screening using mobile units in the population studied leads to a relatively high detection rate for reduced egfr. fourth, the mdrd study equation has not been validated specifically in an unselected mexican population ; therefore, some participants may have been misclassified with respect to the presence or absence of egfr 60 ml / min per 1.73 m. finally, there is no information on the number of homeless people in mexico. in guadalajara, jalisco 's state capital,, the state government has been providing shelter and medical care to this population through the ijas 's unit of assistance to the homeless. our results indicate that more efforts need to be directed to assess the burden of ckd in this setting. in summary, ckd and its risk factors lack of awareness of having diabetes and hypertension is highly common in this population, as is the prevalence of chronic viral infections and substance abuse. consideration should be given to target this high - risk population in programs aimed to prevent ckd and its risk factors in mexico. | little is known about the prevalence of chronic kidney disease (ckd) among the homeless in mexico. the role of substance abuse, alcoholism, and homelessness in ckd has not been properly evaluated. we screened 260 homeless individuals in the state of jalisco, mexico, for the presence of ckd and its risk factors, and compared their characteristics with those from a separate cohort of poor jalisco residents and with a survey of the general mexican population. ckd was more prevalent among the homeless than among the poor jalisco population (22% vs. 15.8%, p=0.0001) ; 16.5% had stage 3, 4.3% stage 4, and 1.2% stage 5. all were unaware of having ckd. only 5.8% knew they had diabetes, but 19% had fasting blood sugar > 126 mg / dl ; 3.5% knew they were hypertensive but 31% had systolic blood pressure 140 mm hg or diastolic blood pressure 90 mm hg. alcoholism was less common than in the poor jalisco population (23.5% vs. 32.3%, p=0.002), but tobacco smoking (34.6% vs. 21.5%, p=0.0001) and substance abuse (18% vs. 1.1%, p=0.0001) were more prevalent among the homeless. likewise, chronic viral infections such as hiv (4.5% vs. 0.3%, p=0.0001) and hcv (7.7% vs. 1.4%, p=0.0001) were also significantly higher among the homeless than in the general population. in conclusion, ckd and its risk factors are highly prevalent among the homeless individuals in jalisco, mexico. lack of awareness of having diabetes and hypertension is highly common, as is substance abuse. programs aiming to prevent ckd and its risk factors in mexico should specifically target this high - risk population. |
mesial temporal lobe epilepsy (mtle) is the most common focal epilepsy affecting adults, and is often associated with pharmacological resistance. temporal lobe resection is, thus, an accepted treatment option for the management of drugresistant mtle. the ideal candidates for surgical resection are those with unilateral ictal eeg discharges and ipsilateral brain magnetic resonance imaging (mri) evidence of hippocampal sclerosis, with reported success rates ranging from 70 to 90% in both randomized controlled trials and longterm longitudinal cohort studies 1, 2, 3, 4, 5. however, temporal lobectomy and hippocampectomy are not suitable for certain patients due to the bilateral nature of the disease and concerns over the risk of memory deficits or even severe amnesia. deep brain stimulation (dbs) is increasingly recognized to be an attractive treatment option for drugresistant epilepsy. by directly targeting a specific neural region or circuit, various brain targets have been investigated, including the anterior and centromedian thalamic nucleus, the cerebellum, the subthalamic nucleus, the caudate nucleus, the motor cortex and the hippocampus 6, 7. two large randomized controlled trials demonstrated the efficacy and safety of intermittent anterior thalamic nucleus (atn) stimulation 8, and responsive stimulation at the sites of seizure origin 9. despite these encouraging results, the optimum stimulation targets and parameters for drugresistant epilepsy have yet to be elucidated. in 2000, velasco. proposed the use of amygdalohippocampal dbs to control mtle 10. in their study, hippocampal stimulation using depth electrodes significantly reduced interictal eeg spikes and improved seizure outcomes in 10 patients scheduled to undergo temporal lobectomy. subsequently, other research groups have demonstrated the efficacy of chronic hippocampal stimulation, with more than half of the patients experiencing a reduction in the frequency of seizures by more than 50% 11, 12, 13, 14, 15, 16, 17. patients with normal mri findings have been reported to have better seizure outcomes after hippocampal stimulation compared to those with hippocampal sclerosis on baseline mri 15. in addition, bilateral hippocampal stimulation has been reported to be more effective than unilateral stimulation 17. the majority of clinical studies have focused on pulsatile high frequency stimulation of the hippocampus, with frequencies ranging from 130 to 200 hz 18. one human study reported temporary suppression of interictal epileptic activity for 510 sec after shortterm low frequency stimulation (13 sec, 13 hz) of temporal lobe mesiobasal epileptic foci 19. experimental evidence in animals has also demonstrated that prolonged low frequency stimulation (1 hz for 1015 min) increases seizure threshold and inhibits the development of amygdalakindled seizures 20. however, the longterm beneficial effect of low frequency hippocampal stimulation has not been confirmed in humans with mtle. in this study, immediately after system internalization, low frequency hippocampal stimulation was applied to patients with mri suggestive of hippocampal sclerosis, whereas patients with normal mri received high frequency stimulation. the study protocol was approved by the institutional ethics board of chang gung memorial hospital, linkou, taiwan. the preoperative workup consisted of carefully describing the seizures, neurological examinations, antiepileptic drug (aed) blood levels, and serial eeg including videoeeg, brain mri, brain fdgpet and/or spect. these patients were selected based on the following criteria : a) suspicion of mtle on the basis of videoeeg monitoring ; b) capable of recording reliable seizure diaries and with a prospective seizure frequency of at least two complex partial seizures (cps) per month during a baseline of three months ; c) failed 3 aeds and currently receiving 13 aeds. resective surgery is commonly suggested as the treatment option for such patients, however brain stimulation was chosen for these five patients due to concerns of possible postoperative significant worsening of memory, the presence of bilateral hippocampal sclerosis or because bilateral epileptogenic zones were suspected. before electrode implantation, daily seizure diaries were prospectively recorded for 3 months, and this served as seizure baseline data, which were compared with seizure data after electrode implantation. all aeds remained unchanged within the first 6 months after stimulation, however they could be subsequently adjusted to minimize side effects or to achieve seizure control. the patients underwent preoperative cerebral computed tomography (ct) to determine the targets and anterior commissure / posterior commissure (ac / pc) reference line stereotactically. under local anesthesia, four contact electrodes (3387, medtronic, minneapolis, mn, usa) were implanted stereotactically using a parasagittal occipital approach, directed along the hippocampus with the anterior contact placed in the hippocampus head, and the remaining three contacts fit within the hippocampus. after electrode implantation, external extension was performed to provide eeg recordings for 57 days before internalization. the hippocampal eeg was recorded via the implanted leads at the same time as scalp eeg. a trial of hippocampal stimulation with 2 days of stimulation off and 2 days with stimulation on was performed. spontaneous clinical seizures were recorded, and the number of interictal epileptiform discharges in the first 3minute period of every hour was identified visually and counted manually. seven days after electrode implantation, a pulse generator (ipg ; 7426 soletrea or 7428 kinetra neurostimulator, medtronic) was placed subcutaneously into the infraclavicular pocket and connected to stimulation electrodes via a lead extension (medtronic 7482 lead extension, medtronic). high frequency (145 hz) or low frequency (5 hz) stimulation was applied, with a pulse width of 90150 s and pulse amplitude of 1 v. of note, high frequency stimulation (145 hz) was initially applied in the patients with normal brain mri based on previous studies, whereas an initial stimulation frequency of 5 hz was applied in those with mri evidence of hippocampal sclerosis. after implantation, the patients were followed up monthly for the first 6 months, and every 3 months thereafter or when clinically required. the aim of this open label study was to improve seizure control for patients with drugresistant mtle, therefore ongoing adjustments of the stimulation parameters were allowed to achieve the best medical outcomes. these adjustments included first gradual increasing the voltage by 0.51 v to a maximum of 6 v, and then adjusting the frequency using either high (range, 90180 hz) or low frequency (range, 35 hz), and finally adjusting the pulse width by 30 s. based on the assumption that the current generated should be more localized than monopolar, pairs of adjacent electrode contacts were stimulated in a bipolar manner with the most anterior electrode contact serving as the anode and the third electrode contact serving as the cathode, or vice versa. intermittent (cycling) stimulation with 1 minute on and 5 minutes off was used. the study protocol was approved by the institutional ethics board of chang gung memorial hospital, linkou, taiwan. the preoperative workup consisted of carefully describing the seizures, neurological examinations, antiepileptic drug (aed) blood levels, and serial eeg including videoeeg, brain mri, brain fdgpet and/or spect. these patients were selected based on the following criteria : a) suspicion of mtle on the basis of videoeeg monitoring ; b) capable of recording reliable seizure diaries and with a prospective seizure frequency of at least two complex partial seizures (cps) per month during a baseline of three months ; c) failed 3 aeds and currently receiving 13 aeds. resective surgery is commonly suggested as the treatment option for such patients, however brain stimulation was chosen for these five patients due to concerns of possible postoperative significant worsening of memory, the presence of bilateral hippocampal sclerosis or because bilateral epileptogenic zones were suspected. before electrode implantation, daily seizure diaries were prospectively recorded for 3 months, and this served as seizure baseline data, which were compared with seizure data after electrode implantation. all aeds remained unchanged within the first 6 months after stimulation, however they could be subsequently adjusted to minimize side effects or to achieve seizure control. the patients underwent preoperative cerebral computed tomography (ct) to determine the targets and anterior commissure / posterior commissure (ac / pc) reference line stereotactically. under local anesthesia, four contact electrodes (3387, medtronic, minneapolis, mn, usa) were implanted stereotactically using a parasagittal occipital approach, directed along the hippocampus with the anterior contact placed in the hippocampus head, and the remaining three contacts fit within the hippocampus. after electrode implantation, external extension was performed to provide eeg recordings for 57 days before internalization. the hippocampal eeg was recorded via the implanted leads at the same time as scalp eeg. a trial of hippocampal stimulation with 2 days of stimulation off and 2 days with stimulation on was performed. spontaneous clinical seizures were recorded, and the number of interictal epileptiform discharges in the first 3minute period of every hour was identified visually and counted manually. seven days after electrode implantation, a pulse generator (ipg ; 7426 soletrea or 7428 kinetra neurostimulator, medtronic) was placed subcutaneously into the infraclavicular pocket and connected to stimulation electrodes via a lead extension (medtronic 7482 lead extension, medtronic). high frequency (145 hz) or low frequency (5 hz) stimulation was applied, with a pulse width of 90150 s and pulse amplitude of 1 v. of note, high frequency stimulation (145 hz) was initially applied in the patients with normal brain mri based on previous studies, whereas an initial stimulation frequency of 5 hz was applied in those with mri evidence of hippocampal sclerosis. after implantation, the patients were followed up monthly for the first 6 months, and every 3 months thereafter or when clinically required. the aim of this open label study was to improve seizure control for patients with drugresistant mtle, therefore ongoing adjustments of the stimulation parameters were allowed to achieve the best medical outcomes. these adjustments included first gradual increasing the voltage by 0.51 v to a maximum of 6 v, and then adjusting the frequency using either high (range, 90180 hz) or low frequency (range, 35 hz), and finally adjusting the pulse width by 30 s. based on the assumption that the current generated should be more localized than monopolar, pairs of adjacent electrode contacts were stimulated in a bipolar manner with the most anterior electrode contact serving as the anode and the third electrode contact serving as the cathode, or vice versa. intermittent (cycling) stimulation with 1 minute on and 5 minutes off was used. each patient received postimplantation videoeeg monitoring, after which unilateral or bilateral interictal epileptiform discharges were recorded from both dbs electrodes and scalp eeg in all of the patients. under stimulation with low (patients 3 and 4) or high (patients 1, 2, and 5) frequency, the number of interictal epileptiform discharges reduced by more than 50% compared to no stimulation in all five patients. throughout the videoeeg recording period, no clinical seizures were recorded in patient 3, whereas the remaining four patients experienced two to six episodes of complex partial seizures. ictal eeg revealed onset from one or more electrode contacts on one of the dbs electrodes, typically consisting of a high frequency, low voltage discharge, occurring seconds before the onset of a clinical seizure, followed by spread to ipsilateral neocortical areas and the contralateral mesial temporal structures. after stimulation was turned on, no seizures were recorded in patients 1 and 5, and patient 4 had fewer seizures compared with the period without stimulation (four without stimulation, and two with stimulation). patient 2 experienced two complex partial seizures when stimulation was turned off, involving fast activities and rhythmic sharp waves over the right dbs electrode contacts, which spread to left mesial temporal and bilateral neocortical areas. external stimulation of the right and left hippocampus for 3 sec then stopped the ictal eeg discharges in this patient. table 1 summarizes the clinical characteristics, imaging studies, individual aed treatment, electrode implantation side, postimplantation aed adjustments, and initial and final stimulation parameters of the patients. one patient had bilateral hippocampal sclerosis with eeg showing interictal and ictal onset foci in the right hippocampus only (patient 3), while one patient had left hippocampal sclerosis, which correlated with the onset of interictal and ictal epileptic activity in the left hippocampus (patient 4). the remaining three patients had nonlesional mtle with seizures arising from the right hippocampus in two (patients 1 and 2) and left hippocampus in one (patient 5) ; these three patients also had interictal independent bilateral hippocampal epileptic activity. two patients received unilateral implantation (patients 1 and 4) and three patients bilateral implantation (patients 2, 3 and 5). patient 1 had normal brain mri with bilateral interictal epileptic activity, and a unilateral quadripolar electrode was implanted over the right hippocampus based on the ictal eeg recordings that showed seizures arising mainly from the right. in the subsequent study, bilateral electrode implantation was used in the patients with either bilateral interictal epileptic activity (patients 2 and 5) or bilateral hippocampal sclerosis (patient 3). patient 4 received unilateral electrode implantation in the left sclerotic hippocampus that correlated with the onset of interictal and ictal epileptic activity in the left hippocampus. table 2 summarizes the interictal and ictal eeg findings, stimulation side and frequency applied. cps, complex partial seizures ; gtcs, generalized tonicclonic seizures ; b, bilateral ; l, leftsided ; r, rightsided ; mt : mesial temporal ; sw, spikeandwave discharge ; mri, magnetic resonance imaging ; aeds, antiepileptic drugs ; pht, phenytoin ; tpm, topiramate ; cnz, clonazepam ; oxc, oxcarbazepine ; vpa, valproic acid ; ltg, lamotrigine ; lvt, levetiracetam ; pgb, pregabalin. b, bilateral ; mt, mesial temporal ; r, right ; l, left. seizure frequency at baseline and during followup was highly variable among the patients, and this variability was reflected in the results (table 3). the baseline seizure frequency was 2.015.3/month, and the average postoperative followup period was 38.4 months (range, 3042 months). the frequency of seizures improved after hippocampal stimulation in all of the patients, with a mean reduction of 45% (range, 2272%). two patients (patients 1 and 5) with a baseline seizure frequency of 2 per month only achieved a 22% reduction after hippocampal stimulation, whereas the three remaining patients (patients 24) with higher frequencies of baseline seizures had a reduction of more than 50%. age, seizure duration and whether unilateral or bilateral stimulation was applied were not correlated with a specific response. figure 1 shows the temporal pattern of the reduction in seizures from baseline to 42 months of stimulation treatment. there was an initial reduction in the frequency of seizures in the first 9 months, which transiently increased by 1218 months and was then followed by a prolonged period of relatively stable seizures reduction. figure 2 further demonstrates changes in the incidence rates of seizures and the corresponding stimulation frequency for each patient. the two patients with hippocampal sclerosis (patients 3 and 4) received low frequency stimulation and experienced a 54% and 72% reduction in seizure frequency after hippocampal stimulation, respectively. although the stimulation frequency was transiently increased to 90 hz from months 3 to 5 in patient 4, there was no significant change in the frequency of seizures between high and low frequency stimulation in this patient. for the three patients with normal brain mri, patient 5 received high frequency stimulation throughout the followup period and only achieved a 22% reduction in the frequency of seizures, whereas the remaining two patients received high frequency stimulation initially which was then adjusted according to their seizure frequency. patient 1 experienced an increase in seizure frequency in the first 6 months after high frequency stimulation, and therefore low frequency stimulation was applied, after which there was a gradual reduction in the frequency of seizures. however, as only a 25% reduction had been achieved after 18 months, high frequency stimulation was subsequently applied again with a modest effect. a dramatic reduction in seizures was noted during the first 3 months in patient 2, after which the frequency of her seizures gradually increased, and therefore low frequency stimulation was applied from month 6 to 12. however, the frequency of her seizures continued to increase, so we changed back to high frequency stimulation which resulted in better seizure control. frequency of seizures over time after stimulator implantation, expressed as a percentage of that at baseline (bl)., no changes were made in the aeds for any of the patients. comparing the seizure frequency between the periods of each aed adjustment revealed an increased seizure frequency in patient 1 with a decrease in clonazepam dose (2.5/m vs. 5/m) at month 7, a decrease in seizure frequency with a low dose of valproic acid at month 8 (2/m), and adjustments were made to maintain the therapeutic level at month 17 (1/m) with the addition of pregabalin at month 42 (1/m). patient 2 had an increase in the doses of oxcarbazepine at month seven with the addition of levetiracetam at month 24. an increase in seizure frequency was noted after the addition of levetiracetam (8/m vs. 11/m), and it was therefore discontinued at month 25. patient 3 was given oxcarbazepine with the discontinuation of valproic acid due to pregnancy at month 38. oxcarbazepine was then discontinued at month 39 and levetiracetam was added at month 40, and no significant changes in seizure frequency were noted during these periods. patient 4 had no changes in medication, and patient 5 had small adjustments in the dose of topiramate at month 19, with the addition of oxcarbazepine at month 27 and a decrease in the dose of topiramate at month 29. most adjustments did not seem to affect seizure frequency except for an exacerbation of seizure control with levetiracetam in patient 2 (month 24). each patient received postimplantation videoeeg monitoring, after which unilateral or bilateral interictal epileptiform discharges were recorded from both dbs electrodes and scalp eeg in all of the patients. under stimulation with low (patients 3 and 4) or high (patients 1, 2, and 5) frequency, the number of interictal epileptiform discharges reduced by more than 50% compared to no stimulation in all five patients. throughout the videoeeg recording period, no clinical seizures were recorded in patient 3, whereas the remaining four patients experienced two to six episodes of complex partial seizures. ictal eeg revealed onset from one or more electrode contacts on one of the dbs electrodes, typically consisting of a high frequency, low voltage discharge, occurring seconds before the onset of a clinical seizure, followed by spread to ipsilateral neocortical areas and the contralateral mesial temporal structures. after stimulation was turned on, no seizures were recorded in patients 1 and 5, and patient 4 had fewer seizures compared with the period without stimulation (four without stimulation, and two with stimulation). patient 2 experienced two complex partial seizures when stimulation was turned off, involving fast activities and rhythmic sharp waves over the right dbs electrode contacts, which spread to left mesial temporal and bilateral neocortical areas. external stimulation of the right and left hippocampus for 3 sec then stopped the ictal eeg discharges in this patient. table 1 summarizes the clinical characteristics, imaging studies, individual aed treatment, electrode implantation side, postimplantation aed adjustments, and initial and final stimulation parameters of the patients. one patient had bilateral hippocampal sclerosis with eeg showing interictal and ictal onset foci in the right hippocampus only (patient 3), while one patient had left hippocampal sclerosis, which correlated with the onset of interictal and ictal epileptic activity in the left hippocampus (patient 4). the remaining three patients had nonlesional mtle with seizures arising from the right hippocampus in two (patients 1 and 2) and left hippocampus in one (patient 5) ; these three patients also had interictal independent bilateral hippocampal epileptic activity. two patients received unilateral implantation (patients 1 and 4) and three patients bilateral implantation (patients 2, 3 and 5). patient 1 had normal brain mri with bilateral interictal epileptic activity, and a unilateral quadripolar electrode was implanted over the right hippocampus based on the ictal eeg recordings that showed seizures arising mainly from the right. in the subsequent study, bilateral electrode implantation was used in the patients with either bilateral interictal epileptic activity (patients 2 and 5) or bilateral hippocampal sclerosis (patient 3). patient 4 received unilateral electrode implantation in the left sclerotic hippocampus that correlated with the onset of interictal and ictal epileptic activity in the left hippocampus. table 2 summarizes the interictal and ictal eeg findings, stimulation side and frequency applied. cps, complex partial seizures ; gtcs, generalized tonicclonic seizures ; b, bilateral ; l, leftsided ; r, rightsided ; mt : mesial temporal ; sw, spikeandwave discharge ; mri, magnetic resonance imaging ; aeds, antiepileptic drugs ; pht, phenytoin ; tpm, topiramate ; cnz, clonazepam ; oxc, oxcarbazepine ; vpa, valproic acid ; ltg, lamotrigine ; lvt, levetiracetam ; pgb, pregabalin. b, bilateral ; mt, mesial temporal ; r, right ; l, left. seizure frequency at baseline and during followup was highly variable among the patients, and this variability was reflected in the results (table 3). the baseline seizure frequency was 2.015.3/month, and the average postoperative followup period was 38.4 months (range, 3042 months). the frequency of seizures improved after hippocampal stimulation in all of the patients, with a mean reduction of 45% (range, 2272%). two patients (patients 1 and 5) with a baseline seizure frequency of 2 per month only achieved a 22% reduction after hippocampal stimulation, whereas the three remaining patients (patients 24) with higher frequencies of baseline seizures had a reduction of more than 50%. age, seizure duration and figure 1 shows the temporal pattern of the reduction in seizures from baseline to 42 months of stimulation treatment. there was an initial reduction in the frequency of seizures in the first 9 months, which transiently increased by 1218 months and was then followed by a prolonged period of relatively stable seizures reduction. figure 2 further demonstrates changes in the incidence rates of seizures and the corresponding stimulation frequency for each patient. the two patients with hippocampal sclerosis (patients 3 and 4) received low frequency stimulation and experienced a 54% and 72% reduction in seizure frequency after hippocampal stimulation, respectively. although the stimulation frequency was transiently increased to 90 hz from months 3 to 5 in patient 4, there was no significant change in the frequency of seizures between high and low frequency stimulation in this patient. for the three patients with normal brain mri, patient 5 received high frequency stimulation throughout the followup period and only achieved a 22% reduction in the frequency of seizures, whereas the remaining two patients received high frequency stimulation initially which was then adjusted according to their seizure frequency. patient 1 experienced an increase in seizure frequency in the first 6 months after high frequency stimulation, and therefore low frequency stimulation was applied, after which there was a gradual reduction in the frequency of seizures. however, as only a 25% reduction had been achieved after 18 months, high frequency stimulation was subsequently applied again with a modest effect. a dramatic reduction in seizures was noted during the first 3 months in patient 2, after which the frequency of her seizures gradually increased, and therefore low frequency stimulation was applied from month 6 to 12. however, the frequency of her seizures continued to increase, so we changed back to high frequency stimulation which resulted in better seizure control. frequency of seizures over time after stimulator implantation, expressed as a percentage of that at baseline (bl). for at least the first 6 months postimplantation, no changes were made in the aeds for any of the patients. comparing the seizure frequency between the periods of each aed adjustment revealed an increased seizure frequency in patient 1 with a decrease in clonazepam dose (2.5/m vs. 5/m) at month 7, a decrease in seizure frequency with a low dose of valproic acid at month 8 (2/m), and adjustments were made to maintain the therapeutic level at month 17 (1/m) with the addition of pregabalin at month 42 (1/m). patient 2 had an increase in the doses of oxcarbazepine at month seven with the addition of levetiracetam at month 24. an increase in seizure frequency was noted after the addition of levetiracetam (8/m vs. 11/m), and it was therefore discontinued at month 25. patient 3 was given oxcarbazepine with the discontinuation of valproic acid due to pregnancy at month 38. oxcarbazepine was then discontinued at month 39 and levetiracetam was added at month 40, and no significant changes in seizure frequency were noted during these periods. patient 4 had no changes in medication, and patient 5 had small adjustments in the dose of topiramate at month 19, with the addition of oxcarbazepine at month 27 and a decrease in the dose of topiramate at month 29. most adjustments did not seem to affect seizure frequency except for an exacerbation of seizure control with levetiracetam in patient 2 (month 24). the results of this study suggest that longterm hippocampal stimulation may be safe and effective for patients with drugresistant mtle. comparisons of the frequency of seizures at baseline and during the postimplantation period revealed a mean reduction in seizures of 45% (range 2272%), including two patients with mri evidence of hippocampal sclerosis. to the best of our knowledge, this article is the first to demonstrate that chronic low frequency hippocampal stimulation can decrease seizure frequency in patients with drugresistant mtle. our results suggest that brain stimulation should be tailored individually and that stimulation parameters should also be taken into consideration when interpreting the efficacy of hippocampal stimulation, especially in those with hippocampal sclerosis. there was an initial reduction in seizure frequency in both the patients with or without hippocampal sclerosis, which increased transiently by 1218 months and was then followed by a prolonged period of relatively stable seizure reduction. because all of the patients received active stimulation immediately after internalization of ipg, we can not rule out factors other than the stimulation as the cause of the improvements. the implant effect (insertional effect) caused by electrode implantation may have contributed to the initial seizure reduction, and thus a doubleblind controlled study with active stimulation and a control group is required to clarify the therapeutic effect achieved by insertion of dbs electrodes alone, with active hippocampal stimulation, or interactions between these factors. it is nonetheless encouraging that the benefits observed during the early phase of this study did not diminish, and in fact seemed to increase over time. although the mechanism remains unknown, steady improvements have been reported with vns 21, atn 8, and responsive stimulation 9 for epilepsy. our results and the observations from a recent longterm study 17 suggest that hippocampal stimulation should be added to this list. given the long duration and severity of epilepsy in our five patients, and that treatment with many aeds failed, the sustained reduction in seizures with hippocampal stimulation is clinically meaningful. among our patients, responses to stimulation were highly variable and individualized. the patients with hippocampal sclerosis had a 5472% reduction in seizures, compared to 2255% in the three patients with normal mri, which is in contrast with findings from a previous report 15. using high frequency (130 hz) hippocampal stimulation in both patients with or without hippocampal sclerosis, velasco and colleagues found that improvements occurred sooner and were more significant in the patients with normal mri in a followup period of 1884 months compared with those with hippocampal sclerosis. the authors speculated that in order to achieve a satisfactory response to stimulation, it is important that the neuronal network be preserved in the stimulated area, and that the severe neuronal reduction that accompanies hippocampal sclerosis may represent a less satisfactory tissue for modulation with stimulation. a recent study by box reported that a large zone of stimulation with either high voltage bipolar dbs (1 v) or quadripolar stimulation is required for patients with hippocampal sclerosis, while a limited zone of stimulation or even a microlesional effect could be sufficient in patients with normal brain mri 11. however, it must be emphasized that the small number of patients and limited data preclude any definite conclusions regarding the effective parameters for patients with or without hippocampal sclerosis. it is generally accepted that stimulus parameters, and particularly frequency, have a profound impact on the effects of the stimulation 22. the mechanism behind this frequencydependent effect on brain stimulation is unclear, and the parameter selection process is still largely empirical. a frequency range between 10 and 70 hz is commonly used to induce kindling and is generally avoided as it may induce seizures. this leaves a high frequency range (> 70 hz) and a low frequency range (100 hz) stimulation is most often used in clinical settings, and experimental results with lowfrequency (< 5 hz) stimulation have been mixed, though chronic human data are lacking. despite its clinical relevance, direct electrical brain stimulation is poorly understood with regard to mechanistic effects at the level of neural circuits, hampering our ability to efficiently determine optimal stimulation parameters for a given patient. thus, ' rational electrotherapy ' for epilepsy remains elusive. the concept of chronic hippocampal stimulation for drugresistant mesial temporal lobe epilepsy (mtle) is not new, and there are several limitations to the small, uncontrolled, open label study by lim and coworkers. however, an important finding is that chronic, openloop, lowfrequency hippocampal stimulation can reduce seizure frequency in drugresistant mtle. mean seizure frequency was nearly halved compared to prestimulation baseline, and the authors are to be commended on the long period of followup (mean 38.4 months). notably, clinical responses to high vs. lowfrequency stimulation were highly variable among the five subjects. there are hints that the underlying pathology (e.g. mesial temporal sclerosis vs. nonlesional) might explain some of this variation, but the small number of subjects precludes any firm conclusions. clinical trials of the rns system and other neurostimulation devices were also not adequately powered to determine subgroup effects based on pathology, but such analyses may be possible with more widespread commercial use of these devices. ideally, rapid determination of optimal stimulation parameters would be guided by electrophysiological biomarkers of treatment response, and identifying a control signal to take the guesswork out of neurostimulation remains a major goal of this field. vikram r. rao, md, phd san francisco, ca, usa 1. loscher w, klitgaard h, twyman re, schmidt d. new avenues for antiepileptic drug discovery and development. carrette s, boon p, sprengers m, raedt r, vonck k. responsive neurostimulation in epilepsy. sprengers m, vonck k, carrette e, marson ag, boon p. deep brain and cortical stimulation for epilepsy. fisher r, salanova v, witt t, worth r, henry t, gross r, oommen k, osorio i, nazzaro j, labar d,. salanova v, witt t, worth r, henry tr, gross re, nazzaro jm, labar d, sperling mr, sharan a, sandok e,. morris gl, 3rd, gloss d, buchhalter j, mack kj, nickels k, harden c. evidencebased guideline update : vagus nerve stimulation for the treatment of epilepsy : report of the guideline development subcommittee of the american academy of neurology. soss j, heck c, murray d, markovic d, oviedo s, corraleleyva g, gordon s, kealey c, degiorgio c. a prospective longterm study of external trigeminal nerve stimulation for drugresistant epilepsy. child nd, stead m, wirrell ec, nickels kc, wetjen nm, lee kh, klassen bt. chronic subthreshold subdural cortical stimulation for the treatment of focal epilepsy originating from eloquent cortex. bergey gk, morrell mj, mizrahi em, goldman a, kingstephens d, nair d, srinivasan s, jobst b, gross re, shields dc,. borchers s, himmelbach m, logothetis n, karnath ho. direct electrical stimulation of human cortex the gold standard for mapping brain functions ? sunderam s, gluckman b, reato d, bikson m. toward rational design of electrical stimulation strategies for epilepsy control. | objectiveelectrical stimulation of the hippocampus offers the possibility to treat patients with mesial temporal lobe epilepsy (mtle) who are not surgical candidates. we report longterm followup results in five patients receiving low or high frequency hippocampal stimulation for drugresistant mtle.materials and methodsthe patients underwent stereotactic implantation of quadripolar stimulating electrodes in the hippocampus. two of the patients received unilateral electrode implantation, while the other three received bilateral implantation. stimulation of the hippocampal electrodes was turned on immediately after the implantation of an implantable pulse generator, with initial stimulation parameters : 1 v, 90150 s, 5 or 145 hz. the frequency of seizures was monitored and compared with preimplantation baseline data.resultstwo men and three women, aged 2761 years were studied, with a mean followup period of 38.4 months (range, 3042 months). the baseline seizure frequency was 2.015.3/month. the five patients had an average 45% (range 2272%) reduction in the frequency of seizures after hippocampal stimulation over the study period. low frequency hippocampal stimulation decreased the frequency of seizures in two patients (by 54% and 72%, respectively). no implantation or stimulationrelated side effects were reported.conclusionselectrical stimulation of the hippocampus is a minimally invasive and reversible method that can improve seizure outcomes in patients with drugresistant mtle. the optimal frequency of stimulation varied from patient to patient and therefore required individual setting. these experimental results warrant further controlled studies with a large patient population to evaluate the longterm effect of hippocampal stimulation with different stimulation parameters. |
ischemic stroke is a heterogeneous disease with various cardiac, arterial, hemodynamic, rheological, and other systemic abnormalities. categorizing patients into classes congruent with their pathophysiology is the key to understanding stroke, providing appropriate treatment, and preventing recurrence. various classification systems are applied to the subtypes of ischemic stroke, each of which had its own strengths and weaknesses. the ocsp (oxfordshire community stroke project classification, bamford classification) relies primarily on clinical syndromes based on the extent and vascular localization of the stroke : total or partial anterior circulation, lacunar, and posterior circulation syndrome.1 the following three etiological classifications have been developed due to acute and secondary preventive therapies being developed based on the understanding of the mechanisms underlying the stroke type : the ninds stroke data bank subtype,2 the lausanne stroke registry,3 and the trial of org 10172 in acute stroke treatment (toast).4 these classifications are based on both clinical and laboratory data, including neuroimaging and vascular and cardiac workups. the three most common etiologies of stroke are atherosclerotic, cardioembolic, and lacunar. with advances in stroke imaging and diagnostic techniques, and the availability of new epidemiological data, evidence - based algorithms have recently been developed to assign etiological categories in the presence of multiple mechanisms. these new categories include the stop stroke study - toast5 and the a - s - c - o (phenotypic).6 while these classification systems have been applied in large studies worldwide, it might be necessary to reassess how asian stroke patients are assigned to the etiological categories. this review addresses concerns about the use of stroke classifications in asian stroke patients, and proposes a classification system that is more specific to the asian population, in conjunction with discussing advances in diagnostic techniques. both the incidence and prevalence of stroke in asia are increasing steadily, probably due to lifestyle changes and the aging of the population. moreover, the burden of stroke is particularly high in asia,7 given that almost two - thirds of the deaths worldwide due to stroke occur in asian countries. the clinical features and epidemiological data related to stroke in asians are different from those in caucasians. the various reasons why a classification system more specific to the asian population needs to be developed are discussed below. first, the proportions and relative importance of stroke subtypes are well known to differ with race and ethnicity (fig. 1).891011 while cardioembolism is the most common (25 - 30%) cause of ischemic stroke in western countries, atherosclerotic stroke accounts for up to 25 - 65% of strokes in asian countries.10 the prevalence of small - vessel disease is also higher in asians than in caucasians ; this subtype accounts for up to one - half of ischemic strokes in asians patients, but only one - fifth of those in caucasian patients.10 as a result, the vast majority of asian patients with ischemic stroke are classified as having disease of large or small cerebral arteries. second, the relative distribution of intracranial, extracranial, and coronary atherosclerosis may differ between asians and caucasians. it was reported that the stroke burden is disproportionately high in east asia, africa, and south america, while the ischemic heart burden is higher in the middle east, north america, australia, and much of europe.12 in addition, the prevalence of intracranial atherosclerosis is high in asians,13 causing 30 - 50% of strokes in asia,14 whereas it is the cause of only 8 - 10% of strokes in north america.15 due to this type of stroke receiving little attention in stroke classification systems, and the relatively low frequency of intracranial atherosclerosis in western countries, patients with intracranial atherosclerosis are often classified as having cryptogenic embolism. however, recent high - resolution mri and pathological studies have revealed the presence of intracranial arterial plaques in these patients.161718 in contrast, patients with a milder degree of intracranial stenosis or large and deep infarcts are likely to be classified as having other cryptogenic causes. third, specific stroke etiologies should be considered in certain stroke populations due to the presence of genetic differences between populations. for example, sickle cell disease can cause stenosis in cerebral vessels, and can result in stroke in blacks but is very rare in east asians. in contrast, the prevalence of moyamoya disease (mmd) is higher in asians than in caucasians. recent genome - wide linkage and exome analyses identified the rnf213 mutation as the most important for susceptibility to mmd among east asian people.192021 the number of east asian patients with mmd has been estimated to be more than 53,800.2223 this is because guidelines for stroke prevention emphasize the use of antiplatelet agents and statins for atherosclerotic strokes and anticoagulants for patients with atrial fibrillation (af) based on the results of large clinical trials. however, from a therapeutic point of view, af might be more complicated in asian patients with ischemic stroke. it might be beneficial to divide the atherosclerotic subtype into isolated intracranial and extracranial (with or without intracranial) atherosclerosis subtypes. differences in clinical and neuroimaging features and risk factors have been reported between extracranial (e.g., cervical carotid) and intracranial atherosclerosis.242526 previous studies have found atherosclerosis to be frequently localized to either the intracranial or the extracranial arterial system, rather than occurring in both systems.2427 more importantly, intracranial stenosis can be caused by diverse conditions, including mmd, dissection, vasculitis, and reversible cerebral vasoconstriction syndrome (fig. atherosclerosis is the main cause of cervical carotid stenosis, with only rare exceptions of carotid dissection, fibromuscular dysplasia, takayasu arteritis, and radiation arteritis being differentiated clinically. in addition, intracranial atherosclerotic stroke can be caused by branch occlusive disease as well as artery - to - artery embolism or hemodynamic impairment.2829 the risk factors, vessel wall pathology, and treatment strategies may differ between these two subtypes of intracranial atherosclerotic stroke.2830313233 patients with branch occlusive disease often show a mild degree of stenosis and are misclassified as having lacunar stroke or other cryptogenic stroke (fig. however, high - resolution mri studies have demonstrated intracranial plaques occluding perforating arteries, which suggests that statin plays a role in these patients. our ongoing serial follow - up high - resolution mri study in patients with intracranial atherosclerotic stroke is currently addressing this issue (clinicaltrial.gov identifier nct02458755). asian investigators are concerned about the definition of stroke subtypes in these patients, and have suggested that lesion size limitations should not be strictly applied to cases of small - vessel occlusions, and that the degree of stenosis in atherosclerotic vessels should not be limiting in determining the presence of intracranial atherosclerotic stroke.10 the pathogenic mechanisms of lacunar stroke are similar to those of hypertensive intracranial hemorrhage, and patients with lacunar stroke often experience hemorrhagic stroke.34 the two subclinical subtypes of lacunar stroke are cerebral deep microbleeds (red type) and leukoaraiosis (white type).35 cerebral microbleeds are more common in asians than in caucasians and are associated with intracranial hemorrhage as well as ischemic stroke (fig. 4),36 while leukoaraiosis may be caused by silent, acute lacunar infarcts.3738 thus, the optimal treatment strategies may differ between the two conditions, and differential risk factors have been reported.394041 the rotterdam scan study showed that use of antiplatelet agents is related to the presence of cerebral microbleeds.42 one prospective study found that the risk of subsequent intracranial bleeding increased with the number of cerebral microbleeds, and that the high risk and mortality of intracranial bleeding outweighed the modest benefit of antithrombotic agents in patients with at least five cerebral microbleeds.43 while the use of anticoagulants is the standard treatment applied to prevent stroke in patients with af, af may not always be the cause of stroke in af patients. in fact, one - sixth of strokes in af patients were reported to be unrelated to af and showed clinical and echocardiographic characteristics distinct from those with af - related stroke.44 most patients with af - unrelated stroke experienced recurrent strokes despite receiving adequate anticoagulation treatment with warfarin (fig. because the prevalence of micro- and macroangiopathy is higher in asians than in caucasians, more asian patients with af are classified as having undetermined etiology with two or more causes, and differentiation of af - related vs. -unrelated stroke may be more important in asians than in caucasians. consideration of the above characteristics leads to the conclusion that the optimal treatment strategies may differ among patients with the same stroke subtype. owing to the paucity of evidence, current guidelines do not provide detailed treatment strategies according to the subclassification of stroke subtype. future studies should investigate different treatment strategies for the various subclassifications, such the optimal dose of statins for intracranial vs. extracranial atherosclerosis, the use of antithrombotics for white vs. red phenotypes of lacunar stroke, and the addition of antiplatelet agents to anticoagulation for af - related vs. -unrelated stroke (table 1). in the meantime, continuous efforts are needed to individualize the treatments provided to asian patients with ischemic stroke. it might be beneficial to divide the atherosclerotic subtype into isolated intracranial and extracranial (with or without intracranial) atherosclerosis subtypes. differences in clinical and neuroimaging features and risk factors have been reported between extracranial (e.g., cervical carotid) and intracranial atherosclerosis.242526 previous studies have found atherosclerosis to be frequently localized to either the intracranial or the extracranial arterial system, rather than occurring in both systems.2427 more importantly, intracranial stenosis can be caused by diverse conditions, including mmd, dissection, vasculitis, and reversible cerebral vasoconstriction syndrome (fig. 2). in contrast, atherosclerosis is the main cause of cervical carotid stenosis, with only rare exceptions of carotid dissection, fibromuscular dysplasia, takayasu arteritis, and radiation arteritis being differentiated clinically. in addition, intracranial atherosclerotic stroke can be caused by branch occlusive disease as well as artery - to - artery embolism or hemodynamic impairment.2829 the risk factors, vessel wall pathology, and treatment strategies may differ between these two subtypes of intracranial atherosclerotic stroke.2830313233 patients with branch occlusive disease often show a mild degree of stenosis and are misclassified as having lacunar stroke or other cryptogenic stroke (fig. however, high - resolution mri studies have demonstrated intracranial plaques occluding perforating arteries, which suggests that statin plays a role in these patients. our ongoing serial follow - up high - resolution mri study in patients with intracranial atherosclerotic stroke is currently addressing this issue (clinicaltrial.gov identifier nct02458755). asian investigators are concerned about the definition of stroke subtypes in these patients, and have suggested that lesion size limitations should not be strictly applied to cases of small - vessel occlusions, and that the degree of stenosis in atherosclerotic vessels should not be limiting in determining the presence of intracranial atherosclerotic stroke.10 the pathogenic mechanisms of lacunar stroke are similar to those of hypertensive intracranial hemorrhage, and patients with lacunar stroke often experience hemorrhagic stroke.34 the two subclinical subtypes of lacunar stroke are cerebral deep microbleeds (red type) and leukoaraiosis (white type).35 cerebral microbleeds are more common in asians than in caucasians and are associated with intracranial hemorrhage as well as ischemic stroke (fig. 4),36 while leukoaraiosis may be caused by silent, acute lacunar infarcts.3738 thus, the optimal treatment strategies may differ between the two conditions, and differential risk factors have been reported.394041 the rotterdam scan study showed that use of antiplatelet agents is related to the presence of cerebral microbleeds.42 one prospective study found that the risk of subsequent intracranial bleeding increased with the number of cerebral microbleeds, and that the high risk and mortality of intracranial bleeding outweighed the modest benefit of antithrombotic agents in patients with at least five cerebral microbleeds.43 while the use of anticoagulants is the standard treatment applied to prevent stroke in patients with af, af may not always be the cause of stroke in af patients. in fact, one - sixth of strokes in af patients were reported to be unrelated to af and showed clinical and echocardiographic characteristics distinct from those with af - related stroke.44 most patients with af - unrelated stroke experienced recurrent strokes despite receiving adequate anticoagulation treatment with warfarin (fig. because the prevalence of micro- and macroangiopathy is higher in asians than in caucasians, more asian patients with af are classified as having undetermined etiology with two or more causes, and differentiation of af - related vs. -unrelated stroke may be more important in asians than in caucasians. consideration of the above characteristics leads to the conclusion that the optimal treatment strategies may differ among patients with the same stroke subtype. owing to the paucity of evidence, current guidelines future studies should investigate different treatment strategies for the various subclassifications, such the optimal dose of statins for intracranial vs. extracranial atherosclerosis, the use of antithrombotics for white vs. red phenotypes of lacunar stroke, and the addition of antiplatelet agents to anticoagulation for af - related vs. -unrelated stroke (table 1). in the meantime, continuous efforts are needed to individualize the treatments provided to asian patients with ischemic stroke. the application of advanced diagnostic technologies may reduce the proportion of patients diagnosed with cryptogenic stroke.45 these techniques could also play a role in diagnosing patients with known vascular and cardiac abnormalities. high - resolution mri can visualize wall pathology (i.e., plaque, dissection, or vasculitis), and it has been shown to be effective in differentiating mmd and intracranial atherosclerosis.4647 a recent high - resolution mri study found that plaques were present in only 26 of 95 korean patients with isolated stenotic lesions in the middle cerebral artery with no or minimal atherosclerotic risk factors, while the remaining 69 patients had nonatherosclerotic high - resolution mri features, such as mmd, dissection, or vasculitis, suggesting a role for nonatherosclerotic pathologies in this population.48 therefore, patients should not be classified as having atherosclerotic subtype simply because they have stenotic lesions on relevant proximal vessels. this is especially true in patients with a relatively healthy risk - factor profile and in asian populations whose intracranial arteries are prone to dissection and carriers of the rnf213 mutation are more common. although intracranial artery dissection is less common than cervical artery dissection in adults of european ethnicity, intracranial artery dissection is reportedly more common in asian populations.49 unlike pediatric mmd, it is often difficult to angiographically differentiate adult mmd from intracranial atherosclerosis. in adult patients with intracranial stenosis and the rnf213 mutation, typical angiographic findings of mmd (i.e., basal collaterals) are not necessarily prominent, and some patients develop typical angiographic findings of mmd on follow - up angiography.50 therefore, high - resolution mri or a follow - up vascular study might be valuable for demonstrating interval changes of basal collaterals and luminal stenosis in these patients. efforts have been made to find and validate possible biomarkers that can reliably predict the risk of stroke in patients with af, including risk schemes51 and serological5253 and genetic54 biomarkers. the use of cardiac imaging biomarkers is another approach for differentiating between cardiogenic and noncardiogenic stroke. for example, af patients with the " chicken wing " type of left atrial appendage (laa) morphology on multidetector cardiac computed tomography are reportedly less likely to have an embolic event after controlling for comorbidities and chads2 score.55 both other56 and our studies57 have shown that the laa volume and laa orifice diameter are both greater in patients with af - related stroke than in those with af - unrelated stroke and those without af (fig. therefore, physicians should consider the possibility of an af - unrelated mechanism if multidetector cardiac computed tomography shows such findings and no thrombus. targeted selection and judicious use of the appropriate tests in the workup of stroke are crucial. an extensive pathogenic workup may paradoxically increase the prevalence of cause - undetermined cases (i.e., cases with 2 determined causes). thus, advanced vascular techniques should be applied to patients with milder stenosis for demonstrating vulnerable plaques, and to those with a relatively healthy risk - factor profile in order to preclude nonatherosclerotic stenosis in which specific treatment may be needed. in addition, antithrombotic usage could be guided by the findings of cardiac imaging (the use of antiplatelet agents in addition to oral anticoagulants to prevent af - unrelated stroke) or gradientecho imaging (while avoiding the use of aggressive antithrombotics in patients with lacunar stroke and multiple cerebral microbleeds). this review of the literature has addressed the need for a more - detailed stroke classification system and the systematic application of advanced diagnostic tests in the evaluation of stroke etiology in asian patients. the continuing advances in technology mean that more diagnostic tests will become available, but this does not mean that it will be possible to apply these advanced techniques in routine clinical practice. continuous efforts are needed to refine the approach applied for the workup of asian patients with ischemic stroke. | both the incidence and prevalence of stroke in asia are steadily increasing, and the burden of stroke is particularly high in asian countries. although strokes in asians and caucasians share many common features, there are some differences that are probably due to differences in lifestyle and genetic background. while there have been advances in the stroke classification system, the assignment of asian stroke patients to etiological categories has received little attention. the current classification system may not be well suited to asian patients with ischemic stroke because the proportions and relative importance of stroke subtypes may differ with race and ethnicity. this review addresses concerns about the use of the current stroke classification system in asian patients with ischemic stroke, and proposes a classification system that is more specific to the asian population, in conjunction with discussing advances in diagnostic techniques. |
endodontically treated teeth with extensive coronal hard tissue defects usually present a higher risk of biomechanical failure than vital teeth, due to the loss of structural integrity. 12345 the conventional method for restoring these teeth is to fabricate post - core supported crowns.6 this was believed to provide better reinforcement of the residual tooth structure.789 however, many studies have reported that placing a post only promotes retention of the crown and preparation for a post may weaken the residual tooth tissues, thus increasing the chance for accidental tooth fracture.101112 moreover, to obtain a sufficient ferrule height of 1.5 - 2 mm, additional treatments such as crown lengthening methods are recommended under some circumstances, which may lead to even lower fracture resistance of the tooth - crown complex.1314 minimally invasive preparation to preserve a maximum amount of tooth structure is considered the gold standard for restoring teeth. endocrowns, with a decay - orientated design concept,15 have become increasingly popular because of their advantages in preserving the maximum tooth tissue, reducing the need for auxiliary retentive geometry and saving treatment time and expense as fewer operation steps are involved. moreover, the development of dental cad / cam systems provides a novel means of chair - side design and automatic fabrication of all ceramic restorations, especially the ceramic endocrown that constructs both the crown and the core as a single unit. several in vitro studies have reported that molars and maxillary premolars with ceramic endocrowns showed better fracture resistance than those with conventional postcore supported ceramic crowns.151617 however, there were few studies about the fracture strength of endocrowns of the mandibular premolars, whose coronal and radicular geometries are quite different from their maxillary counterparts. yet there have rarely been studies regarding the differences between the fracture resistance of intact mandibular premolars and teeth restored with endocrowns and conventional crowns. therefore, the aim of this study was to assess the fracture resistance and failure patterns of endodontically treated mandibular premolars restored with ceramic endocrowns and conventional post - core supported ceramic crowns, using intact teeth as a control. this study was approved by the chinese pla general hospital ethics committee (process number : s2015 - 008 - 01). all the premolars were of similar size and shape, selected by similar mesiodistal and buccolingual dimensions at the cementoenamel junction (cej) and root lengths measured with a caliper with an accuracy of 0.05 mm (chengliang tools group co. ltd, chengdu, china), permitting a maximum deviation of 10% from the mean. after the dental plaque, calculus, and periodontal soft tissues cleaned, the teeth were stored in 0.5% chloramine solution at 4. the specimens were randomly assigned into three groups (n = 10) : the intact teeth group (gi), the endocrown group (ge), and the conventional post - core supported crown group (gc). except for the intact teeth in gi, the crown portions of all the specimens were sectioned 1.5 mm above the cej and endodontic treatments were performed. the working length was visually determined by placing a # 10 k - file into the canals. root canals were instrumented with k - files # 10 - 20 and enlarged by nickel - titanium rotary instruments (protaper, dentsply maillefer, tulsa, ok, usa) according to the manufacturer 's instructions.. then the root canals were obturated with laterally condensed gutta - percha (dentsply maillefer, tulsa, ok, usa) and sealer (ah - plus, dentsply maillefer, tulsa, ok, usa). the gutta - percha was removed by a small carbide bur to 7 mm below the top of the chamber walls. a flowable resin composite (filtek z350xt flowable, 3 m espe, st. paul, mn, usa) was then put to fill the canals, and 5 mm depth of the pulp chamber retention form was reserved. the cavity preparation process was subjected to elimination of the retentive areas and alignment of the axial walls. a total occlusal convergence of 2 - 5 was performed by a tapered diamond bur. the circular butt margin and a central retention cavity were prepared and smoothed according to figure 1 and measured with the caliper. in gc, the gutta - perchas were removed from the root canals, leaving a 3 - 5 mm apical gutta - percha seal. the root canals were enlarged with burs included in the post system. each glass fiber post egreve, france) was tried in and cut to adequate length so as to keep 3 mm buried in the composite resin core. the canal walls and the exposed portion of the coronal dentin were etched and the bonding agent (adper single bond plus, 3 m espe) was applied. the post was cemented using a dual resin cement (relyx arc ; 3 m espe) according to manufacturer 's instructions. then a 3 mm - high core was built up with a resin core (muticore flow, ivoclar vivadent). each tooth was prepared with a 1.5 mm - high ferrule and a 1.0 mmwidth margin at the cej (fig. 1b). using the cerec 3d system (sirona dental systems gmbh, bensheim, germany), endocrowns and conventional crowns were designed and fabricated from lithium disilicate (e.max cad, ivoclar vivadent, schaan, liechtenstein). after the ceramic restorations being fitted and polished, the tissue surfaces of the restorations were etched with 5% hydrofluoric acid (ips ceramic etching gel, ivoclar vivadent, schaan, liechtenstein) and pretreated by a silanecoupling agent (monobond s ; ivoclar vivadent). the adhesive surfaces of the teeth were etched and pretreated by dentin primer (syntac, ivoclar vivadent) and dentin adhesive (syntac, ivoclar vivadent). all crowns were luted with a dual cure resin cement (variolink ii, ivoclar vivadent) according to manufacturer 's instructions. a 0.2 mm layer of polyether impression material (impregum penta soft, 3 m espe) was applied on the root surface. after that, all specimens were embedded in self - cured acrylic resin (shanghai dental material company, shanghai, china), leaving a height of 2 mm apically to the cej, then stored in saline at 37 for a week. all specimens were subjected to 5000 cycles of thermocycling at 5 to 55 for 30 seconds dwell time in a thermal cycling machine (c-501f, will laboratory supplies ltd, suzhou, china). subsequently, the specimens were stored in a humid environment for 24 hours before testing. each specimen was fixed in a universal testing machine (wdw-100, changchun, china), with a stainless - steel sphere (5 mm in diameter) contacting the lingual plane of the buccal cusps. then a load was applied at a cross - head speed of 1.0 mm / min and at an angle of 45 to the long axis of the tooth until fracture occurred (fig. the fracture resistance of each specimen was recorded in newton, and its fracture mode was classified according to the following patterns:1819 favorable failures : repairable fractures of the teeth / restorations above the level of bone simulation ; unfavorable failures : non - repairable fractures below the level of bone simulation. data were statistically analyzed with spss 17.0 (spss inc, chicago, il, usa). one - way analysis of variance (anova) and lsd post hoc test (=.05) were used to detect the statistically significant variations among the groups. gi revealed the highest mean fracture resistance compared with those of ge and gc, and the differences were of statistical significance (p <.01). no significant difference was found between ge and gc (p =.702) (table 2). most failure modes in gi were favorable, while most failure modes in ge and gc were unfavorable. in group gi, most fracture areas were above the level of bone simulation on the buccal side. on the other hand, in group ge and gc, majority fracture lines invaded into the bone simulation areas on the buccal side. advances in cad / cam all - ceramic materials and adhesive dentistry, especially regarding the high bonding capacity of the lithium - disilicate ceramics, provide highly conservative approaches for endodontically treated teeth with better mechanical character, biocompatibility, and efficiency. the endocrown is built on a decay - orientated preparation to preserve a maximum amount of tooth tissue for bonding instead of extensive preparation for retention. in previous studies, some studies found that endocrowns for endodontically treated maxillary premolars had higher fracture resistance than the conventional restorations,1617 while others reported that endocrowns appeared inadequate for premolars compared with conventional crowns.2021 moreover, there has not been any recommendation about the validity of the endocrown for endodontically treated mandibular premolars, which have quite different anatomic forms from maxillary premolars. this study showed that the fracture resistances were 479.1 n for ge and 510.1 n for gc, and anova analysis demonstrated no significant difference between them. compared with maxillary premolar, the mandibular premolar had a smaller crown, which caused insufficient resistance forms of residual tooth tissue. a smaller pulp chamber area of mandibular premolars leads to a decreased bonding area and therefore to the decline of retention force. moreover, the narrow neck of mandibular premolar is more obvious and the diameter of the root is smaller than that of the maxillary premolar, which might lead to poor stress transmission patterns from crown to root. in addition, for fiber post - core retained conventional crowns, the post inserted into the root canal connects the crown and root as a whole, and the post enhances the retention of the restoration. the elastic modulus of the fiber post close to that of dentin is conducive to the stress concentration. 22 all these might be the reasons that the endocrown does n't show a higher mean fracture resistance value than conventional crown in mandibular premolars. most of the failure modes of both the endocrown and the conventional groups of mandibular premolars in our study were unfavorable. this was consistent with a report about maxillary premolars.16 it can be inferred that in most situations, the mechanical failure of restored premolars, including both maxillary and mandibular premolars, whether by endocrowns or by conventional crowns, may mainly due to the weakening of the residual tooth structures instead of ceramic materials and resin cement materials. the loading methods might have been one of the reasons for the differences between our study and previous researches. in our study, the load was applied at an angle of 45 to the long axis of the tooth to simulate occlusal forces in both lateral and long - axis directions, while an axial loading was adopted in most previous studies. instead of the middle fossa, our loading position was on the lingual slope of the buccal cusp, which was the key occlusal contact area of mandibular premolars. the morphological characters of the mandibular premolars, such as a sharply narrowed neck at cej, a narrower bucco - lingual width compared with the maxillary premolars, may also contribute to the divergent results shown in our study. our study also showed that the fracture resistance of the tooth - restoration complexes was lower than that of intact mandibular premolars. therefore, it is important to reduce the chance of fracture failure when making either endocrown - morphological design or conventional design on mandibular premolars. reducing the height and inclines of the cusps and minimizing the mesio - distal and bucco - lingual width adopting polyceramics or other materials, with relatively low modulus of elasticity and increasing strength, may also be options to reduce the risk of unfavorable failure under certain circumstances. under the condition of this in - vitro study, we discovered that the endocrown and the conventional glass fiber postcore retained ceramic crown showed similar fracture resistance, which was significantly lower than that of the intact mandibular premolar. however, clinical long - term follow - up studies are required to support these findings. for the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance compared with the conventional method. both of the two methods can not rehabilitate endodontically treated teeth with the same fracture resistances as that of intact mandibular premolars. | purposethis in - vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post - core retained crowns.materials and methodsthirty mandibular premolars were assigned into three groups (n=10) : gi, intact teeth ; ge, teeth with endocrowns ; gc, teeth with conventional post - core supported crowns. except for the teeth in group gi, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. both endocrowns and conventional crowns were fabricated from lithium - disilicate blocks using a cerec 3d cad / cam unit. all specimens were subjected to thermocycling and then to 45 oblique compressive load until fracture occurred. the fracture resistance and failure mode of each specimen were recorded. data were analyzed with one - way anova and lsd post hoc test (=.05).resultsthe fracture resistances of ge and gc were significantly lower than that of gi (p<.01), while no significant difference was found between ge and gc (p=.702). as of the failure mode, most of the specimens in ge and gc were unfavorable while a higher occurrence of favorable failure mode was presented in gi.conclusionfor the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. both of the two methods can not rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have. |
forearm rotation occurs around an axis connecting the center of the radial head and the fovea of the distal ulna. various treatments for malunion have been reported, but the optimal method for reduction remains controversial. we planned this study to determine numerical values indicative of healing treatment during deformation of the forearm. we therefore investigated cases in which corrective osteotomy was performed for malunion without dislocation of the elbow or wrist. our hypothesis was that increased differences between the axes of forearm and proximal radius would be associated with increased deterioration of forearm rotational motion. data from patients with corrective osteotomies for malunited forearm fractures without dislocation of the elbow or wrist were reviewed retrospectively. patient demographics were reviewed, including age, sex, and interval between injury and surgery. mean interval between initial injury and surgery was 21 months (range, 347 months). mean duration of follow - up was 12 months (range, 622 months). this retrospective study included eight cases (6 men, 2 women), and mean patient age was 15 years (range, 1021 years). fracture type was radioulnar shaft fracture in five cases and radial shaft fracture in three cases. initial treatment of forearm fractures comprised conservative treatment in five cases and operative treatment in three cases. pre- and postoperative ranges of motion were obtained from clinical charts. we performed corrective osteotomy of the radius alone in five cases, ulna alone in one case, and both radius and ulna in two cases. intraoperatively, we attempted to restore the normal shape of both bones according to intraoperative fluoroscopic images and anteroposterior and lateral radiographs. we evaluated plain radiographic images using medical image analysis software (rapideye ; toshiba medical systems, tochigi, japan). anteroposterior and lateral radiographs of the forearm were obtained using the same position of forearm rotation (in the neutral position, if possible), with the elbow in 90 of flexion, and the wrist in neutral alignment. two lines were drawn : the axis of the proximal radial head ; and the forearm axis. the angle between these two lines was then measured on both lateral and anteroposterior radiographs (fig. if the tuberosity of the radius and styloid were not on opposite sides of the bone, we determined malrotation by plain radiography. with the ulna, the coronoid process of the ulna and the ulnar styloid process are normally on opposing sides, so we used this relationship to assess malrotation of the ulna. the longitudinal (rotational) axis of the forearm runs from the center of the radial head proximally to the fovea of the distal ulna. the axis of the proximal radius runs between the center of the radial head and the radial neck. proximal radial tilt angle () represents the angle between the rotational axis of the forearm and the axis of the proximal radius. differences in forearm rotation and in radiological assessments were analyzed using the mann - whitney u test. we evaluated plain radiographic images using medical image analysis software (rapideye ; toshiba medical systems, tochigi, japan). anteroposterior and lateral radiographs of the forearm were obtained using the same position of forearm rotation (in the neutral position, if possible), with the elbow in 90 of flexion, and the wrist in neutral alignment. two lines were drawn : the axis of the proximal radial head ; and the forearm axis. the angle between these two lines was then measured on both lateral and anteroposterior radiographs (fig. if the tuberosity of the radius and styloid were not on opposite sides of the bone, we determined malrotation by plain radiography. with the ulna, the coronoid process of the ulna and the ulnar styloid process are normally on opposing sides, so we used this relationship to assess malrotation of the ulna. the longitudinal (rotational) axis of the forearm runs from the center of the radial head proximally to the fovea of the distal ulna. the axis of the proximal radius runs between the center of the radial head and the radial neck. proximal radial tilt angle () represents the angle between the rotational axis of the forearm and the axis of the proximal radius. differences in forearm rotation and in radiological assessments were analyzed using the mann - whitney u test. mean forearm rotation increased from 81 (range, 0135) preoperatively to 138 (range, 108175) postoperatively. mean proximal radial tilt angle improved from 14 to 9.3, compared to 3.3 on the normal side. postoperative rotation correlated with proximal radial tilt angle, and severe malunion affected the range of forearm rotation (fig. 2). three patients were considered to show radial malrotation and no patients displayed ulnar malrotation. mean rotation in malrotation cases was 128 17.2, compared to 145 26.9 in the remaining cases. the forearm is composed of the radius and ulna, which are linked by the interosseous membrane and intercalated between the elbow and wrist. the forearm rotation axis runs through the center of the radial head to the ulnar head, and radial motion around the ulna results in forearm rotation. angular deformity of the forearm affects forearm rotation, so the treatment for malunion of the forearm should be provided by treating the radius and ulna as bones of a joint. although corrective osteotomy can achieve good rotation within 1 year after injury, the factors contributing to clinical results remain unclear and no reports have clarified how deformity of the axis of rotational motion affects forearm rotation. the acceptable range of deformity at initial treatment for fracture remains contentious, particularly in pediatric cases, due to good remodeling ability. our series included skeletally immature cases, but a previous report showed that in diaphyseal fractures, the distal radial epiphyseal plate realigned well only in children under 10 years of age, so our results appear reasonable. some recent papers have reported three - dimensional computed tomography (3dct) and computer - assisted osteotomy for malunion. indeed, we think that malunion of the forearm should be treated in 3d, but we investigated the indicators for corrective osteotomy only on plain radiographs in consideration of radiation exposure and usability. we tried to reduce malrotation, and only three cases showed malunion and the degrees of deformity were mild. differences in each parameter were also relatively small and the small sample size could have limited the statistical power of the analyses. bones, ligaments and soft tissues would affect rotation, but the rigid body element must provide the primary effects on forearm rotation. we evaluated the results of corrective osteotomy for forearm fracture malunion using plain radiography. to improve the range of rotation we think the angle between the axis of rotation of the forearm and the axis of the proximal radius offers a useful indicator for corrective osteotomy. | abstractforearm rotation occurs around an axis connecting the center of the radial head and the fovea of the distal ulna. the purpose of the present study was to demonstrate the usefulness of the difference between forearm and proximal radial axis in the treatment of malunited forearm fractures. we reviewed the results of eight corrective osteotomies for malunited fractures of the forearm without dislocations of the wrist or elbow. subjects were 6 men and 2 women (mean age, 15 years ; range, 1021 years). corrective osteotomy was performed at the fracture site. preoperatively and at final follow - up, the arc of forearm rotation was recorded and anteroposterior and lateral x - rays were taken. proximal radius tilt was defined as the angle between the rotational axis of the forearm and the axis of the proximal radius. corrective osteotomy improved proximal radius tilt in all cases. three patients were considered to have malrotation. postoperative rotational arc correlated with proximal radial tilt (r = 0.83). no significant difference in rotational arc was evident between malunited cases and the remaining cases. to improve forearm rotation, corrective osteotomy should be planned to minimize proximal radius tilt.key words : forearm fracture, corrective osteotomy, malunion, axis |
although tnf itself was not discovered until the 1970s, a physician named william coley first noted the phenomenon of tumor necrosis at the turn of the 20th century. the tumors of some of his cancer patients shrank after they had acquired streptococcal infections (1). but the inherent dangers of injecting humans with a toxic soup of bacterial endotoxins prevented coley 's observation from being converted into an antitumor therapy. researchers, however, hoped to separate the tumor - blasting factor from the toxic mess. lloyd old and his team at the memorial sloan kettering cancer center (new york, ny) finally zeroed in on serum tnf from bacterium - primed, endotoxin - challenged mice in 1975 (2). bruce beutler (left) and anthony cerami tnf was immediately included with the likes of interferon-, il-2, and monoclonal antibodies as the next best hope in cancer treatment. by the mid-1980s tnf therapy not only failed to shrink tumors but also caused side effects. and just across the street from sloan kettering, a group from rockefeller university headed by anthony cerami would soon publish data that would put a further damper on the tnf - as - cure idea. his main interest was in understanding the basis of cachexia the weight loss associated with many chronic diseases, such as cancer and tuberculosis. in the 1970s, while testing drugs designed to rid cattle of the parasite trypanosoma, cerami noticed that the animals continued to waste away even though the parasites were dying off. the continued weight loss was not drug induced, as parasite - infested antelopes also responded to the drug but showed no further wasting. cachexia, cerami surmised, might be due to a host factor that was meant to fight the infection but became a threat when produced in amounts that overwhelmed the body. cerami soon found a reliable biochemical read - out for cachexia : lipaemia, the accumulation of lipids in the blood due to the suppression of a fat - metabolizing enzyme (3). the hypothetical host factor, cerami realized, might be suppressing this enzyme, lipoprotein lipase (lpl), thus triggering a fat storage problem and cachexia. he and a post - doctoral associate, masanobu kawakami, tested this hypothesis in a mouse model of endotoxin - induced cachexia. mice that were genetically susceptible to endotoxin had deficient lpl activity after an injection of bacterial lipopolysaccharide (lps), whereas endotoxin - resistant mice had normal lpl activity. serum from lps - treated sensitive mice triggered lpl suppression in normally resistant mice, suggesting the presence of the cachexia - inducing host factor in the serum. the task of purifying this mystery protein was taken up by bruce beutler, another of cerami 's post - doctoral associate. the team had previously found that a macrophage cell line produced copious amounts of the lpl - suppressing factor when stimulated by endotoxin (4). the macrophage prep was also a better starting point for protein purification compared with the messy mouse serum. beutler then took a year to purify the protein, which the team named cachectin. they published their discoveries in the journal of experimental medicine (5, 6). the team 's collaborators at the scripps institute (la jolla, ca), however, found that cachectin shared the same biological activity with tnf. a comparison of cachectin 's sequence with that of the newly sequenced human tnf solidified the link. the team added this later discovery as a footnote to their already - accepted paper (5). the identification of cachectin as the benign cytokine tnf created a furor in the field, especially as the other biological activities of cachectin mimicked the side effects seen in the tnf - treated cancer patients. everyone else was advocating for tnf to be given to patients, says cerami. we wanted to get rid of it. his team later found that blocking tnf activity using antibodies reduced infection - induced inflammation and endotoxin - induced lethality (7). today, anti - tnf drugs are successfully used in the treatment of inflammatory diseases such as rheumatoid arthritis and psoriasis. | in the early 1980s, in search of the cytokine that triggers disease- associated weight loss and lethal shock, anthony cerami and bruce beutler purified cachectin. they soon found out that their malevolent cytokine already had another name tumor necrosis factor (tnf)and was being lauded as a potential antitumor agent. |
as explained in more detail in our previous report, in the course of a screening campaign of new chemical entities against infectious agents, compounds 1 and 2 were found active on our whole cell measles virus replication assay (figure 1). an initial structure activity study led to confirmation of the potential of this original chemotype and to greatly improved antiviral compounds, including the 2-(3-isopropyloxy-1h - pyrazol-1-yl)pyrimidine derivative 3, which displayed a subnanomolar mic50 on this measles virus replication assay (figure 1). moreover, a search for the biochemical mechanism of action of this series pointed out that, as for other recently reported compounds, the inhibition of the cellular dihydroorotate dehydrogenase (dhodh) is at the origin of the antiviral effect. from these results, in order to increase the chemical diversity possible in this series, we initially replaced the pyrimidine ring by a pyridine moiety because its additional carbon would provide another position for structure activity studies. accordingly, as in our first report, we are describing here a succession of synthesis campaigns followed by comments on the antiviral effect obtained. most of these results are presented in tables in which the first result column (%) provides the yield of the reaction depicted and the second column describes the observed antiviral effect expressed as pmic50 values. this corresponds to the negative log of the minimum compound concentration required to inhibit viral growth by 50% when using a recombinant measles virus strain expressing a luciferase as a reporter. we first undertook the preparation of the 2-pyridyl derivatives 6a t depicted in table 1. as compound 2, these analogues were prepared from the 3-ethoxypyrazole 4(10) and commercially available 2-halogenopyridines 5a p. from 2-halogenopyridines featuring electron - attracting substituents, the use of cesium carbonate in dry dimethylformamide or acetonitrile and heating at 150 c with a microwave oven for 1 h efficiently gave the n - pyridyl derivatives. on the other hand, from 2-fluoropyridines featuring electron donating substituents, a temperature of 180 c (under pressure) was found necessary and, because of its decomposition into dimethylamine, dimethylformamide was replaced by acetonitrile. for the preparation of compound 6a(7) or 6p, we used 2-bromopyridine 5a or 5p and taillefer and cristau copper - catalyzed arylation conditions. moreover, as for compound 1, the regioselectivity of these reactions was unambiguously checked in a couple of instances. miyaura reaction between cyclopropyl boronic acid and the 5-bromo derivatives 6j. alternatively, as described in the experimental section, the 2-fluoropyridines 5q s were prepared via suzuki miyaura reactions between cyclopropyl boronic acid and the corresponding 5-bromo precursors. from them, the analogues 6q s were then obtained by n - arylation of 4. the n - arylation of compound 4 with 2-(6-fluoropyridin-3-yl)propan-2-ol (5 t) gave the hydroxylated analogue 6 t, and a reduction of its alcohol function led to the 5-isopropyl derivative 6u. interestingly, the palladium - catalyzed hydrogenation at room temperature of 6 t was mostly inefficient. to avoid the use of high hydrogen pressure, which would probably have also resulted in the hydrogenation of the pyridine ring, we used triethylsilane in the presence of trifluoromethanesulfonic acid and achieved its hydrogenation into 6u in an unoptimized 24% yield. concerning the antiviral effects, as seen in table 1, the methyl scan leading to compounds 2 and 6b d, pointed out the importance of occupying the position 5 of the pyridine ring for a tangible antiviral effect (pmic50 = 6.2 for compound 2). the lack of substituents or the introduction of a small fluorine atom seen in 6a, 6e, and 6f also gave almost inactive compounds although some improvement can be observed when comparing the antiviral effect of compound 6a (pmic50 < 5) and the 3-fluorinated derivative 6e (pmic50 = 5.2). the recourse to a trifluoromethyl (compound 6 g) or a chlorine atom (compound 6i) on position 5 gave slightly more active analogues (both pmic50 of 5.5), but the bigger bromine present in compound 6j did not improve this further (pmic50 = 5.3). on the other hand, the combination of the 3-fluoro and 5-bromo substituents seen in compound 6k appeared to be the cause of slight synergic effect (pmic50 = 5.9) when considering the pmic50 of the parent monosubstituted compounds 6e and 6j (respectively 5.2 and 5.3). in contrast to a fluorine group, the 3-methyl substituent of 5-brominated derivative 6l led only to a weak antiviral effect. a loss of effect was also seen for the three derivatives 6 m, 6n, and 6o featuring respectively a cyano, an ester, or a methyl ketone on position 5. to a lesser extent, a similar phenomenon was observed with the methoxy of compound 6p (pmic50 = 5.5). it is only the introduction of the cyclopropyl group featured by compound 6q that led to an improved inhibition of the virus replication (pmic50 = 7.0 nm). combination of this group with the fluorine of compound 6r led to an unchanged antiviral effect (pmic50 7.0), whereas the nitrile of compound 6s replacing this fluorine caused a loss (pmic50 = 6.6). interestingly, the branched isopropyl derivative 6u turns out to be an order of magnitude less active (pmic50 = 5.9) than the cyclopropyl analogue 6q. finally, the polar hydroxyl moiety of compound 6 t (pmic50 5.3) led to an even bigger loss of effect in comparison with the hydrogen - bearing isopropyl group of compound 6u. < 2%. using 2-bromopyridine and a copper catalyst. using 2-bromo-5-methoxypyridine and a copper catalyst see text and experimental section. from 6j, see text and experimental section. from 6 t, see text and experimental section. as for the pyrimidine - containing series, by arylation of the 4-aryloxypyrazoles 7a q with the 2-fluoropyridine 5q, we prepared the 4-aryloxy derivatives 8a q depicted in table 2. later on, we also prepared the corresponding pyridazine homologues 10b q from 3-chloro-6-cyclopropylpyridazine (9). for comparison purposes, table 2 the pattern of antiviral effect for analogues 8a q featuring a 5-cyclopylpyridine is somehow mirroring the one seen for the 5-ethylpyrimidyl bearing homologues. in comparison with the phenoxy - bearing compound 8a (pmic50 = 7.0), ortho - substitution with a fluorine, a chlorine of a bromine atom improved the antiviral effect (pmic50 of respectively 7.7, 7.9, and 7.8). a trifluoromethyl group instead of these halogens had a lesser effect (compound 8e, pmic50 = 7.3). shifting this trifluoromethyl group on the meta position of the phenoxy ring did not alter much the antiviral effect (pmic50 = 7.1 for 8f), whereas placing this group on the para position led to a substantial loss (pmic50 = 5.3 for 8 g). a similar trend is observed with the fluorine atom of compounds 8k m, the ortho - fluoro derivative 8k being the most active (pmic50 = 7.4) and the para - fluorinated analogue 8 m far less effective (pmic50 = 5.9) although ortho - substituted derivatives are the most active but, as in the pyrimidine series, with a pmic50 of 9.0, the 2,6-difluorophenoxy derivative 8q is the best antiviral of this group of analogues. very similar comments can be made on the antiviral effects of compounds 10b q, and the differences between any given pair of analogues is always less than an order of magnitude. (i) cs2co3, mecn, microwave 180 c 6 h or 2 h. log(mic50), mic50 in mol / l, standard deviation < 2%. as depicted in scheme 1, we also explored the preparation and use of precursors featuring a 5-cyclopropylpyridine moiety to which additional chemistry would allow the introduction of various group on the carbon 4 of the pyrazole ring. the n - arylation of the 4-iodopyrazole 11a(5) with 5-cyclopropyl-2-fluoropyridine (5q) had to be conducted at 180 c for up to 12 h and only led to a rather small amount (13%) of the 4-iodinated target compound 12a along with some (9%) of the reduced derivative 12b. this is quite in contrast with the 55% yield we reported for the n - arylation of compound 11a with 2-fluoropyridine at the same temperature for 3 h. extensive analysis of the reaction mixture pointed out the presence of a large amount of 3-ethoxy-5-methylpyrazole (11b) resulting from the reduction of the 4-iodopyrazole 11a under this long reaction time. although an explanation for this reduction is not obvious (a carbene occurrence ?), we suggest that the much decreased reactivity of the electron rich 5-cyclopropyl-2-fluoropyridine (5q) toward nucleophilic reaction in comparison with 2-fluoropyridine is allowing the necessary time for this side reaction to proceed to a large extent. somehow related to such behavior is the quick evolution of iodine, or iodochloride, upon heating 3-ethoxy-4-iodopyrazole in hydrochloric acid. in any case, the iodinated target compound 12b was treated with butyllithium followed by the addition of benzoyl chloride to give the 4-benzoyl derivative 13 in 44% yield. in an attempt to improve these results, we undertook the n - arylation of the 4-bromopyrazole 11c. under similar conditions, the sodium borohydride reduction of ketone 13 led to the secondary alcohol 14a, whereas the addition of methyl lithium to ketone 13 provided an access to the tertiary alcohol 14b. from compound 12c, palladium - catalyzed reactions allowed the preparation of few analogues. miyaura reaction with phenylboronic acid gave 33% of compound 15, whereas negishi reactions with benzylzinc bromide or (1-phenylethyl)zinc chloride gave compounds 6q and 16 in, respectively, 71 and 42%. of note in this part is an optimization of the preparation of 1-phenylethylzinc chloride using the lithium chloride, dibromoethane, and trimethysilyl chloride - based protocol as well as the use of cphos instead of xphos in an attempt to lessen the extent of -elimination possible with (1-phenylethyl)zinc chloride. concerning the antiviral effects of these compound, as for the pyrimidine - containing series, the benzoyl derivative 13 (pmic50 = 6.9) was slightly less effective than the corresponding methylene analogue 6q (pmic50 = 7.0). on the other hand, the alcohol 14a retained a more sizable antiviral effect (pmic50 = 7.4) but the gain is far from what we could observe in the case of the pyrimidine - containing series. introducing an additional methyl on this carbon led the tertiary alcohol 14b and to a much reduced antiviral activity (pmic50 = 6.1). = 7.0), leading to the much less effective analogue 16 (pmic50 = 5.2). finally, the low antiviral effect of the 4-phenyl derivative 15 (pmic50 = 6.0) pointed out the importance of a bridge between the pyrazole and the aromatic ring. (i) 5-cyclopropyl-2-fluoropyridine (5q), mecn, microwave 180 c 12 h ; (ii) (a) buli, thf, 78 c, (b) phcocl, 78 20 c ; (iii) nabh4, etoh ; (iv) meli, thf, 20 c ; (v) phb(oh)2, pddppf, cs2co3, proh / h2o ; (vi) phch2znbr, xphos, or phchmezncl, cphos, pd(oac)2, thf, 50 c. as depicted in table 3, we then retained the 2,6-difluorophenoxy component of compound 8q and prepared the 2-pyridyl derivatives 18a s. analogues 18a n were obtained by the n - arylation of the pyrazole 7q by the corresponding 2-halogenopyridines 5a, 5 g, 5j o, and 5q t and the 2-fluoropyridines 17l n (prepared as described in the experimental section). in the case of the methoxy - bearing analogue 18p, we used again the 2-bromo-5-methoxypyridine (5p) and taillefer cristau copper - catalyzed arylation conditions. the following n - arylation of compound 7q with this 2-bromopyridine 17n had to be conducted at a relatively lower temperature to avoid extensive decomposition, and the pure difluoromethylene - bearing analogue 18n was thus obtained in a modest 12% yield. a rather slow catalytic hydrogenation of the cyclopropyl ring of compound 18d enabled an access to the propyl analogue 18o in a 30% yield. the preparation of analogues 18p r turned out to be possible as, under basic conditions, the fluorine atom on the pyridine ring of 18d could be displaced by methanol, dimethylamine, or benzylalcohol using high temperature and a microwave oven. in the last case, the catalytic hydrogenation of the resulting 3-benzyloxyderivative 18r led to the 3-hydroxypyridinyl derivative 18s. unexpectedly, despite few trials, the direct hydrolysis of compound 18d into 18s, using sodium hydroxide in thf, was not successful. as seen in table 3, with these compounds we could assess the effect of varying the pyridine substituents while retaining a 2,6-difluorophenoxy moiety. going from the hydrogen of the n - pyridine derivative 18a (pmic50 = 4.9) to the 5-methyl homologue 18b (pmic50 = 7.6), a 400-fold improvement of the antiviral effect was observed. from then, the 5-cyclopropyl group of compound 8q (pmic50 = 9) provided another order of magnitude. on the other hand, the ethyl group of compound 18l (pmic50 = 7.1) caused a loss of antiviral effect. this is actually reminiscent of what was observed for the 5-isopropyl bearing compound 6u (pmic50 = 5.9) in comparison with the 5-cyclopropyl bearing analogue 6q (pmic50 = 7.0) described above. moreover, it is contrasting with what we previously reported for the 5-ethyl and 5-cyclopropyl pyrimidine analogues which had mostly the same antiviral effect (pmic50 = 9.2 and 8.9). replacement of the methyl group of compound 18b (pmic50 = 7.6) by the trifluoromethyl of compound 18c (pmic50 = 6.5) led to more than a 10-fold loss. if adding a fluorine atom on carbon 3 of the pyridine ring has very little effect when comparing the 5-ethyl bearing analogues 18l and 18 m (pmic50 both of 7.1), a 2-fold loss was seen in comparison with the 5-cyclopropyl pair 8q and 18d (pmic50 = 9 and 8.6). on the other hand, as for the pair of analogues 6j and 6k, a fluorine on the same position is improving the antiviral effect when comparing the activity of the 5-bromo derivatives 18f and 18 g (pmic50 = 6.3 and 6.9). attempts to introduce various polar groups on carbon 5 of the pyridine ring such as the one seen in compound 18i k did not improve the antiviral effect, and the two fluorine atoms of compound 18n (pmic50 = 7.1) had no effect in comparison with the 5-ethyl analogue 18l (pmic50 = 7.1). only relatively small losses were observed for the bis - substitued derivatives 18p s featuring a cyclopropyl group. interestingly, the influence of the methoxy moiety of compound 18p (pmic50 = 7.5) is comparable to the dimethylaminated derivative 18q (pmic50 = 7.5), whereas the hydroxyl - bearing analogue 18o (pmic50 = 8.1) displayed a relatively stronger activity. somehow unexpectedly, the larger benzyloxy group of compound 18r (pmic50 = 7) only caused a relatively small loss of antiviral effect. in any case, none of the analogues described in table 3 displayed an antiviral effect better than the nanomolar level of compound 8q. < 2%. using 2-bromo-5-methoxypyridine and a copper catalyst, see text and experimental section. by catalytic reduction of 18d reduction of 18r, see text and experimental section. as depicted in figure 2 and fully described in the experimental section, from the 2,6-difluorophenoxy pyrazole 7q, some other possible azines - bearing compounds such as 3-pyridyl and 5-pyrimidyl, the 2-pyrazinyl and the 1,2,4-triazine derivatives were also prepared. the 3-pyridyl bearing compounds 19a c were made by the taillefer cristau copper catalyzed n - arylation of 7q with the commercially available 5-bromo-2-methyl, 5-bromo-2-ethyl, and 5-bromo-2-methoxypyridines. the 5-pyrimidyl derivative 20a was also made with the copper catalyzed reaction between 7q and 5-bromo-2-tert - butylpyrimidine. for the preparation of the 5-cyclopropyl analogue 20b, we had recourse to the n - arylation of compound 7q with a small sample of 2-cyclopropylpyrimidin-5-ylboronic acid using lam and chan reaction conditions. the n - arylation of 2,6-difluorophenoxy pyrazole 7q with 2,5-dibromopyrazine led to the 5-bromopyrazine analogue 21a. the methoxy - bearing analogue 21c was then made from 21a by displacement of the bromine atom with methanol under basic conditions. as described in the experimental section, the preparation of 2-bromo-5-cyclopropylpyrazine allowed the synthesis of the cyclopropyl - bearing analogue 21d by n - arylation. in similar ways, the pyridazine - bearing analogues 10q and 22a b were prepared from the corresponding chloropyridazines. the methoxy or ethoxy - bearing analogues 22c d were made by displacement of the chlorine atom of compound 22b with the corresponding alcohols because an n - arylation trials using 3-chloro-6-methoxypyridazine led to extensive side reactions, including, as seen by lc / ms, a methylation of compound 7q. the 1,2,4-triazine - bearing analogue 23 was prepared in a modest 10% yield by the n - arylation of compound 7q with 6-ethyl-3-(methylthio)-1,2,4-triazin-5-ol (preparation given) at 200 c. finally, as fully described in the experimental section, we also prepared the n - ethyl imidazole - bearing analogues 24 by the copper catalyzed n - arylation of compound 7q with 1-ethyl-4-iodo-1h - imidazole. in view of the antiviral effect of the azine - bearing analogues 8q, 10q, 19b, and 21d, one fact clearly stands out. as for the 2-pyrimidyl analogues previously studied, an ethyl or a cyclopropyl group para to the pyrazole ring often provides a low nanomolar antiviral effect. however, this is not true for the 2-cyclopropylpyrimidine derivative 20b (pmic50 = 6.8) or the triazine 23 (pmic50 = 7.6), which is in this case featuring an additional hydroxyl group. attempt to replace such alkyl groups by side chains of similar size but featuring more polar groups mostly failed, as seen for the 2-methoxypyridine derivative 19c (pmic50 = 6.0), the 2-methoxypyrazine 21c (pmic50 = 6.1), or the 3-methoxypyridazine 22c (pmic50 = 7.1). the same trend was observed for the halogen - bearing analogues 21a b (pmic50 = 5.5 and 5.3) or 22b (pmic50 = 6.8). finally, the relatively low antiviral effect of the n - ethylimidazole derivative 23 may be another example of the trend which points at a detrimental effect of polar atoms (a nitrogen in this case) in the vicinity of this alkyl side chain. the elucidation of the biochemical target of our series has led us to publish a survey of all the reported inhibitors of dhodh along with their uses. this review pointed out that teriflunomide (25) depicted in figure 3 is the only human dhodh inhibitor used in medicine against autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. interestingly, in our cellular assay, teriflunomide (25) displayed an antiviral effect with an mic50 of 5 m, which is reflected in the previously reported ic50 of 1 m on recombinant human dhodh. this relatively modest effect of teriflunomide (25) on the enzyme had actually triggered the search and the discovery of some off - target inhibitions in the past. this value can also be compared to the enzymatic ic50 of 10 nm reported for brequinar (26), a stronger inhibitor of dhodh which underwent disappointing phase ii trials against solid tumors. structure and antiviral effect of teriflunomide (25) and brequinar (26). to assess the potential of our series in comparison with these compounds, we undertook an array of biological assays using compound 18d. in cellulo, as depicted in figure 4, we could point out that compound 18d is affecting pyrimidine nucleoside biosynthesis. indeed, while adding 18d at concentration varying from 4 to 100 nm blocked the measles virus replication in cells, the addition of the pyrimidine - containing nucleoside uridine at 10 g / ml (figure 4a) restored its replication. on the other hand, the addition of the purine - containing nucleoside guanosine at 10 g / ml did not restore this (figure 4b). moreover, a restored virus replication was seen with the addition of orotic acid at 3 mm (figure 4c) while, as seen in figure 4d, dihydroorotic acid at 3 mm had no such effect. these last results thus narrowed down the biochemical target of compound 18d to dhodh. accordingly, as reported, we produced recombinant human dhodh and compound 18d was indeed found to be an inhibitor of this enzyme with an ic50 of 25 5 nm. t cells were infected with recombinant mv strain expressing luciferase (multiplicity of infection = 0.1), incubated with dmso alone or 18d at 4, 20, or 100 nm, and culture medium was supplemented with uridine (a), guanosine (b), orotate (c), or dihydroorotate (d). experiment was performed in triplicate, and data represent means sd. by using a metabolite analysis protocol, the hek-293 t cells content in adenosine triphosphate (atp), guanosine triphosphate (gtp), cytidine triphosphate (ctp), and uridine triphosphate (utp) treated for 24 h with various concentration of compound 18d could be determined. as seen in table 4, intracellular concentrations of uridine and cytidine collapsed in cells treated with 18d, whereas purine nucleotides concentrations were slightly increased, likely as a consequence of the control loops connecting purine and pyrimidine metabolic pathways. this strongly demonstrates in cell cultures the inhibition of de novo pyrimidine biosynthesis by 18d. we recently reported that the inhibition of pyrimidine biosynthesis amplifies cellular response to pathogen - associated molecular patterns such as exogenous rna molecules. when transfecting cells with small synthetic rna molecules (ssrna) that mimic viral rna genomes or transcripts, activation of the interferon - stimulated response element (isre) that drives innate immunity genes was enhanced by dhodh inhibition. as depicted in figure 5, we thus monitored that compound 18d increased the expression of an isre - luciferase reporter gene when transfecting cells with ssrna molecules. this adds to the panel of cellular assays that support the inhibition of pyrimidine biosynthesis by compound 18d. (top) hek-293 t cells with the isre - luciferase reporter gene (sting-37 cells) were transfected with increasing doses of synthetic 5-triphosphate rna molecules (ssrna) and incubated in the presence of compound 18d or dmso alone in 96-well cultures plates. after 24 h, luciferase expression was determined. (bottom) same experiment was performed in the presence of uridine at 30 g / ml. both experiments were performed in duplicate, and the data represents means sd. aside from their antiviral effect, pyrimidine biosynthesis inhibitors are also well - known for blocking the proliferation of lymphocytes, and this probably accounts for their immunosuppressive property in vivo. accordingly, we also determined the effect of compound 18d on the growth of jurkat t lymphocyte cell line, which has been demonstrated to be sensitive to dhodh inhibitors. as shown in figure 6, compound 18d strongly inhibited jurkat cells proliferation (ic50 = 0.02 m) and its level of inhibition compared favorably with brequinar (ic50 = 0.2 m) or teriflunomide (ic50 close to 60 m, data not shown). inhibition (%) of jurkat cells proliferation by compound 18d and brequinar (26). jurkat cells were incubated with increasing doses of 18d or brequinar. as a control, cells were treated with dmso alone. at t = 0 and after 72 h of culture, the number of living cells was determined using the celltiter - glo reagent. the inhibition of cellular proliferation is expressed as a percentage relative to dmso - treated control wells. also of much interest is the recent demonstration that plasmodium falciparum dhodh is a valid target for the treatment of malaria and that a dual inhibition of human and p. falciparum dhodh was noticed for some series. accordingly, we screened all these antiviral compounds for a potential inhibition of p. falciparum growth. no growth inhibition was seen in a cellular assay at the concentration of 8.66 g / ml (data not shown) for all the compounds aside from a modest effect for the pyridazine - bearing analogues 10q and 22a (ic50 of 0.33 and 0.47 m). of course, these values led us to prepare many more pyridazine - bearing analogues, including compound 10b p, but all of them turned out to be at least an order of magnitude less effective on the parasite growth. just in case, compound 10q and 22a were also assayed for their eventual inhibition of recombinant p. falciparum dhodh but they turned out to be completely devoid of effect on this biochemical assay. in conclusion, along with our previous report, this study made good use of the alkoxypyrazole chemistry we previously reported, which somehow cleared a sort of chemical blind spot existing in pyrazole chemistry. the ensuing screenings of the resulting new chemical entities led us to extensively explore the structure activity relationship of a new series of human dhodh inhibitors. of note is a cellular antiviral assay which greatly simplified the evaluation of the compounds prepared and probably filtered out analogues of low cell membrane permeability. concerning the potential of this series of inhibitors against immune diseases, the current success of teriflunomide (25) has led to renewed interest in the search for better inhibitors of human dhodh. quite a few strong acid - bearing human dhodh inhibitors have thus emerged and are currently at various stage of clinical development for the treatments of autoimmune diseases or graft rejection. because all these compounds, as well as brequinar (26), are featuring a carboxylic acid function, we are currently working on the selection of compounds displaying optimal preclinical properties in order to secure a proof of effect on an animal model of autoimmune disease. this endeavor is based on the reasonable assumption that our carboxylic acid - free series of inhibitors could display a different and beneficial pharmacological profile in comparison with the inhibitors currently in preclinical or clinical studies. however, so far, our best inhibitors can be only considered as tools as a too short microsomal stability has been a recurrent feature for this series. indeed, low half - life values were observed for compounds such as 8k (t1/2 = 4 min) or 8q (t1/2 = 6 min) on human microsomes and only modest improvements were seen for the fluorine - protected compound 18d (t1/2 = 2741 min), the hydroxy - protected compound 18s (t1/2 = 38 min), or the less active analogues 22c (t1/2 = 22 min) and 18 g (t1/2 = 60 min). related to this aspect is a report mentioning similar difficulties for another type of n - arylated pyrazoles. accordingly, additional work will be required to improve this and the x - ray based determination of the binding mode of this series of inhibitors to human dhodh could be very useful in this regard. finally, these results are probably an illustration of the interest of designing whole cell / phenotypic assays of sufficient sensitivity (a bioluminescent virus in the present case). this led us to detect an unexpected biological effect and provided a simple biological mean not only to undertake further structure activity study but also to find the mode of action of this series of compounds. hek-293 t cells (atcc) were maintained in dulbecco s modified eagle s medium (dmem ; gibco - invitrogen) containing 10% fetal calf serum (fcs), penicillin, and streptomycin at 37 c and 5% co2. antiviral activity of compounds was determined using a recombinant vaccine strain of measles virus expressing firefly luciferase (rmv2/luc) from an additional transcription unit. to determine the mic50, hek-293 t cells were infected with rmv2/luc (moi = 0.1) and incubated in 96-well culture plates at 3 10 cells / well with increasing concentrations of compounds or dmso alone. the mic50 corresponds to the concentration of a compound inhibiting luciferase activity by 50%. compounds were screened against p. falciparum 3d7 strain parasites with a starting parasitemia of 0.8% at 2% hematocrit in 96-well plates. parasite growth and proliferation was measured using sybr green i. the assay was performed as described previously. this enzyme was expressed as recombinant proteins in escherichia coli and purified as previously described. steady - state kinetic analysis was performed using the 2,5-dichloroindophenol (dcip)-based spectrophotometric method as described. enzyme and substrate concentrations were : dhodh (e = 510 nm) and substrates (0.2 mm l - dihydroorotate and 0.02 mm coqd). the 100 compound stock solutions were made in dmso by covering a 3-fold dilution series such that final concentrations in the assay for inhibition ranged from 0.001100 m. one day later, culture medium was supplemented with increasing doses of compound 18d or dmso alone. after an additional 24 h of culture, cells were harvested, carefully counted, and monitored for viability by trypan blue exclusion. sting-37 cell line was previously described and corresponds to hek-293 t cells that express luciferase under control of five interferon - stimulated response elements (isre). cells were transfected with increasing amounts of ssrna molecules using jetprime pei reagents (polyplus transfection) and dispensed in 96-well plates at 35000 cells / well in 100 l of dulbecco s modified eagle s medium (dmem ; gibco - invitrogen) containing 10% fetal calf serum (fcs), penicillin, and streptomycin. dmso or compound 18d was added to culture medium, and after mixing, cells were cultured for 24 h at 37 c and 5% co2. finally, firefly luciferase activity was determined using the bright - glo reagent following manufacturer s recommendations (promega). jurkat cells were cultured in at 5 10 cells per well in flat - bottom 96-well culture dishes. cells were maintained at 37 c and 5% co2 in rpmi (gibco - invitrogen) containing 10% fetal calf serum (fcs), pyruvate sodium, nonessential amino acids, penicillin, and streptomycin. number of living cells was determined by quantification of adenosine triphosphate (atp) in culture wells using the celltiter - glo assay (promega) following manufacturer s recommendations. this luciferase - based assay evaluates by atp quantification the number of metabolically active cells in culture wells. the microsomal stability assessments were subcontracted to oroxcell, romainville, france. a biotage initiator 2 h nmr and c nmr spectra were recorded on a bruker avance 400 spectrometer at 400 and 100 mhz, respectively. shifts () are given in ppm with respect to the tms signal, and coupling constants (j) are given in hertz. column chromatography were performed either on merck silica gel 60 (0.0350.070 mm) or neutral alumina containing 1.5% of added water using a solvent pump and an automated collecting system driven by a uv detector set to 254 nm unless required otherwise. sample deposition was carried out by adsorption of the mixture to be purified on a small amount of the solid phase followed by its deposition of the top of the column. the low resolution mass spectra were obtained on an agilent 1100 series lc / msd system using an atmospheric electrospray ionization system and the high resolution mass spectra (hrms) were obtained using a waters micromass q - tof with an electrospray ion source. unless stated otherwise, a purity of at least 95% was obtained for all the compounds by means of chromatography, recrystallization, or distillation and this level of purity was established by tlc, lc / ms and nmr spectroscopy under an inert atmosphere, 5-bromo-2-fluoropyridine (5j) (17 g, 0.096 mol) and cesium carbonate (114 g, 0.35 mol) were dispersed in a 95/5 vv mixture of toluene and water (500 ml). this was degassed by gently bubbling argon in the reaction and cyclopropyl boronic acid (10 g, 0.11 mol) and [1,1-bis(diphenyl phosphino)ferrocene ] dichloropalladium complexed with dichloromethane (1.45 g, 0.0018 mol) was added. the flask was heated to reflux for 40 min ; upon cooling, the suspension was diluted in ethyl acetate, and the filtered organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a distillation at ambient pressure (e760 mm = 206 c) to give a volatile oil (8.06 g, 62%). a lesser pure fraction (about 7%) h nmr (cdcl3) : 0.68 (m, 2h), 1.02 (m, 2h), 1.91 (m, 1h), 6.81 (m, 1h), 7.42 (m, 1h), 8.02 (m, 1h). c nmr (cdcl3) : 8.6, 12.2, 108.9 (38 hz) ; 136.7 (4 hz) ; 138.1 (7 hz) ; 145.5 (14 hz) ; 162.2 (236 hz). hrms : too volatile for analysis. by using the procedure described for the preparation of 5-cyclopropyl-2-fluoropyridine (5q), this compound was obtained from 5-bromo-2,3-difluoropyrimidine (5k) in 63% yield, as a volatile oil, after a chromatography over silica gel (cyclohexane dichloromethane 2/1) h nmr (cdcl3) : 0.71 (m, 2h), 1.06 (m, 2h), 1.94 (m, 1h), 7.18 (m, 1h), 7.78 (m, 1h). c nmr (cdcl3) : 9.0, 12.2, 123.5 (3 and 15 hz) ; 139.3, 139.4 (5 and 13 hz) ; 145.4 (29 and 260 hz) ; 150.4 (15 and 236 hz). hrms : too volatile for analysis. by using the procedure described for the preparation of 5-cyclopropyl-2-fluoropyridine (5q), this compound was obtained from 5-bromo-2-chloronicotinonitrile in 53% yield, as a solid, after a chromatography over silica gel (cyclohexane dichloromethane 1/1). h nmr (cdcl3) : 0.79 (m, 2h), 1.17 (m, 2h), 1.97 (m, 1h), 7.59 (d, 1h, j = 2.5), 8.38 (d, 1h, j = 2.5). c nmr (cdcl3) : 9.8, 12.3, 110.2, 114.8, 139.1, 139.3, 149.4. hrms calcd for c9h7brn2 + h : 222.9871. found : 222.9840. under an inert atmosphere, 5-bromo-2-fluoropyridine (5j) (3.12 g, 17.7 mmol) was dissolved in dry ether (100 ml) and the solution cooled to 78 c. butyl lithium (9.3 ml, 18.6 mmol, 2n in cyclohexane) was added. the resulting precipitate was stirred at 78 c for 15 mn, acetone (0.4 ml, 90 mmol, dried over 4 molecular sieves) was added, and the reaction was allowed to warm back to room temperature for 30 mn. this was diluted with a saturated solution of ammonium chloride and extracted with ethyl acetate. the organic layer was washed with a saturated solution of ammonium chloride and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was further purified by a chromatography over silica gel (dichloromethane ethanol 98.5/1.5) to yield compound 5 t as an oil (0.57 g, 20%). h nmr (cdcl3, slight differences with the reported one) : 1.63 (s, 6h), 1.89 (s, 1h), 6.91 (dd, 1h, j = 2.8 and 8.4), 7.94 (m, 1h), 8.33 (m, 1h). c nmr (cdcl3) : 31.8, 71.1, 108.8 (37 hz) ; 138.0 (8 hz) ; 142.0 (4 hz) ; 144.0 (14 hz) ; 162.6 (238 hz). hrms calcd for c8h10fno + h : 156.0825. found : 156.0791. under an inert atmosphere, 5-bromo-2-fluoropyridine (5j) (5.35 g, 30.39 mmol) and potassium carbonate (16.8 g, 121.59 mmol) were dissolved in dry dimethylformamide (75 ml, dried over 4 molecular sieves). oxygen was removed from this solution by a slow stream of argon, and [1,1-bis(diphenylphosphino)ferrocene ] dichloropalladium complexed with dichloromethane (0.62 g, 1.52 mmol) was added, followed by a 1 m solution of triethylborane (40 ml, 40.4 mmol) which was slowly added with a syringe. this darkening suspension was heated at 85 c for 4 h using an oil bath. the resulting black suspension was diluted in diethyl ether and water, the organic layer was washed with water 5 times and brine, dried over magnesium sulfate, and cautiously concentrated to dryness to take into account the volatility of the reaction product. the residue was purified by a chromatography over silica gel (cyclohexane dichloromethane from 2/3 to 1/4) to yield the 5-ethyl derivative 17l as a volatile oil (1.52 g, 40%). h nmr (cdcl3) : 1.25 (t, 3h, j = 7.6), 2.65 (q, 2h, j = 7.6), 6.84 (dd, 1h, j = 3.0 and 8.4), 7.61 (m, 1h), 8.03 (m, 1h). c nmr (cdcl3) : 15.3, 25.1, 108.9 (37 hz) ; 136.7 (4 hz) ; 140.5 (8 hz) ; 145.6 (14 hz) ; 162.2 (236 hz). hrms : too volatile for analysis. by using the protocol described for the synthesis of 2-fluoro-5-ethylpyridine (17l), compound 17k was obtained in 17% yield from 5-bromo-2,3-difluoropyridine (5q) as a volatile oil after a chromatography over silica gel (cyclohexane dichloromethane from 1/1 to 1/4). h nmr (cdcl3) : 1.27 (t, 3h, j = 7.6), 2.68 (q, 2h, j = 7.6), 7.40 (m, 1h), 7.80 (m, 1h). c nmr (cdcl3) : 15.1, 25.0, 125.9 (3 and 14 hz) ; 138.9 (4 hz), 140.3 (5 and 12 hz), 145.2 (28 and 260 hz), 150.4 (14 and 235 hz). hrms : too volatile for analysis. another fraction of this chromatography led, after a recrystallization in cyclohexane, to 5,5,6,6-tetrafluoro-3,3-bipyridine in a 25% yield as fine needles. h nmr (cdcl3) : 7.75 (m, 2h), 8.18 (m, 2h). c nmr (cdcl3) : 125.2 (4 and 16 hz), 131.1 (5 hz), 139.7 (6 and 13 hz), 145.7 (29 and 264 hz), 152.2 (14 and 242 hz). calcd for c10h4f4n2 : c, 52.64 ; h, 1.77 ; n, 12.28. found : c, 52.44 ; h, 1.84 ; n, 12.26. in a closed teflon flask, 1-(6-bromopyridin-3-yl)ethanone (5o) (0.95 g, 4.75 mmol) and bis(2-methoxyethyl)aminosulfur trifluoride (3.6 g, 11.4 mmol) were stirred for 7 days (as only a 78% conversion was monitored by h nmr, a longer reaction time may lead to an even better yield). this was diluted in water, solid calcium chloride was added, and the solution was extracted with ethyl acetate. the organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness (not for too long, this compound is volatile). the residue was purified by a chromatography over silica gel (cyclohexane dichloromethane 1/1) to yield the difluorinated pyridine 17n as a colorless and volatile oil (0.57 g, 54%). h nmr (cdcl3) : 1.96 (t, 3h, j = 18), 7.57 (d, 1h, j = 8.3), 7.69 (dd, 1h, j = 2.3 and 8.3), 8.20 (m, 1h). c nmr (cdcl3) : 25.7 (29 hz) ; 120.5 (240 hz) ; 128.0, 133.2 (27 hz) ; 135.0 (5 hz) ; 143.7 (2 hz) ; 146.9 (6 hz). hrms calcd for c7h6brf2n + h : 221.9730. found : 221.9667. under an inert atmosphere, 2,5-dibromopyrazine (0.21 g, 0.88 mmol) and cesium carbonate (1.12 g, 3.43 mmol) were dispersed in a 95/5 v / v mixture of toluene and water (5 ml). this was degassed by gently bubbling argon in the reaction, and [1,1-bis(diphenylphosphino)ferrocene ] dichloropalladium complexed with dichloromethane (0.018 g, 0.022 mmol) and cyclopropyl boronic acid (0.098 g, 1. the flask was heated to reflux for 30 min ; upon cooling, the suspension was diluted in ethyl acetate, the filtered organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. this was residue was purified by a chromatography over silica gel (cyclohexane ethyl acetate 97/3 9/1 to yield the 2-bromo-5-cyclopropylpyrazine (0.08 g, 45%) as a solid. h nmr (cdcl3) : 1.09 (m, 4h), 2.03 (m, 1h), 8.26 (d, 1h, j = 1.4), 8.48 (d, 1h, j = 1.4). c nmr (cdcl3) : 10.6, 14.1, 136.8, 143.0, 146.5. 157.3. hrms calcd for c7h7brn2 + h : 198.9871. found : 198.9784. by using the same procedure used for the preparation of 2-bromo-5-cyclopropylpyrazine, this compound was obtained in 40% yield as a solid (on a much larger scale), from 3,6-dichloropyridazine, after two consecutive chromatography processes over silica gel (dichloromethane ethanol 99/1) and the second using only dichloromethane to yield the 2-bromo-5-cyclopropylpyrazine. h nmr (cdcl3) : 1.20 (m, 4h), 2.15 (m, 1h), 7.21 (d, 1h, j = 8.8), 7.35 (d, 1h, j = 8.8). c nmr (cdcl3) : 10.9, 15.4, 127.0, 127.6, 154.2, 164.0. hrms calcd for c7h7cln2 + h : 155.0376. found : 155.0354. first step. preparation of 2-(2-carbamothioylhydrazono)butanoic acid : as previously described, 2-oxobutyric acid (3.15 g, 0.0308 mol) and thiosemicarbazide (2.81 g, 0.0308 mol) were stirred in water (60 ml) at 70 c for 10 min. this was left to cool, and the precipitate was filtered, washed with water, and dried at 50 c under vacuum to give the hydrazone (4.47 g, 82%) as 4/17 mixture of isomers. h nmr (dmso - d6) : (major isomer) 0.93 (t, 3h, j = 7.5), 2.65 (q, 2h, j = 7.5), 8.59 (s, 1h), 8.68 (s, 1h), 10.85 (s, 1h) ; (minor isomer) 1.08 (t, 3h, j = 7.4), 2.44 (q, 2h, j = 7.4), 8.01 (s, 1h), 8.65 (s, 1h), 12.15 (s, 1h). c nmr (dmso - d6) major isomer, 10.8, 18.7, 143.3, 164.8, 180.4 ; minor isomer, 11.6, 26.8, 139.0, 164.4, 179.1. preparation of 6-ethyl-3-mercapto-1,2,4-triazin-5-ol : as previously described, the hydrazone (4.24 g, 0.0269 mol) and sodium carbonate (2.56 g, 0.0269 mol) were heated to reflux in water (300 ml) for 3 h. the solution was made acid with acetic acid and extracted with ethyl acetate. the organic layer was washed with brine, dried over sodium sulfate, and concentrated to dryness to yield the 1,2,4-triazin-5-ol as a white powder (3.09 g, 86%). h nmr (dmso - d6) : 1.07 (t, 3h, j = 7.6), 2.50 (q, 2h, j = 7.6), 12.99 (s, 1h), 13.28 (s, 1h). c nmr (dmso - d6) : 10.3, 23.0, 152.1, 153.5, 173.7. methylation of this compound : in water (30 ml), sodium hydroxide (1.25 g, 0.031 mol) was dissolved, and after cooling, the 1,2,4-triazin-5-ol (2.46 g, 0.015 mol) was dissolved. methyl iodide (1.07 ml, 0.017 mmol), diluted in tetrahydrofuran (2 ml), was then slowly added. the solution was stirred at room temperature for 4 h ; this was diluted with water, made acid with acetic acid, and extracted with ethyl acetate. the organic layer was washed with brine, dried over magnesium sulfate, and concentrated to dryness to yield the pure thioether as a white powder (2.28 g, 85%). h nmr (dmso - d6) : 1.07 (t, 3h, j = 7.6), 2.50 (q, 2h, j = 7.6), 12.99 (s, h), 13.28 (s, 1h). c nmr (dmso - d6) : 10.5, 12.5, 23.6, 153.6, 160.7, 164.4. step 1 : under a moisture - protected atmosphere, a 50/50 mixture of 4,5-diiodo-1h - imidazole and 2,4,5-triiodo-1h - imidazole, obtained when iodinating imidazole using the described procedure, and ethyl iodide (2.14 g, 0.0137 mol) potassium carbonate (3.97 g, 0.0286 mol) were stirred in dimethylformamide (50 ml, dried over 4a molecular sieve) for 22 h. this was diluted in water, extracted with ethyl acetate, and the organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a chromatography over silica gel (dichloromethane ethanol 99/1 to 97/3) to give the 1-ethyl-4,5-diiodo-1h - imidazole (1.79 g, 37% from imidazole). h nmr (cdcl3) : 1.43 (t, 3h, j = 7.3), 4.03 (q, 2h, j = 7.3), 7.64 (s, 1h). c nmr (cdcl3) : 16.1, 44.9, 81.8, 95.8, 140.2. note : the 1-ethyl-2,4,5-triiodo-1h - imidazole also obtained in this step (1.90 g, 29% from imidazole) can be selectively and completely reduced back to the 1-ethyl-4,5-diiodo-1h - imidazole by refluxing it with an excess of sodium sulfite in a 1/1 mixture of water and ethanol for 30 mn. step 2 : under argon, 1-ethyl-4,5-diiodo-1h - imidazole (1.8 g, 0.0051 mol) was dissolved in dry tetrahydrofuran (20 ml). the solution was cooled to 0 c, and ethyl magnesium (1.8 ml, 0.0054 mol, 3 m solution in ether) was added. the resulting suspension was stirred for 30 min, quenched with an excess of ammonium chloride in water, and extracted with ethyl acetate. the organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a chromatography over silica gel (dichloromethane ethanol 98/2) to give the 1-ethyl-4-iodo-1h - imidazole (0.78 g, 68%) as an oil. h nmr (cdcl3) : 1.45 (t, 3h, j = 7.3), 3.98 (q, 2h, j = 7.3), 7.01 (d, 1h, j = 1.3), 7.38 (d, 1h, j = 1.3). c nmr (cdcl3) : 16.1, 42.2, 81.6, 124.0, 138.1. in a reaction vial designed for microwave heating, the considered alkoxypyrazole (2 mmol), the considered halogenated heteroaryl (2.2 mmol), and cesium carbonate (2.8 mmol) were stirred in dimethylformamide or acetonitrile (3 ml) as specified this was heated using a microwave at a temperature between 120 and 180 c for the specified duration. the resulting suspension was diluted in water and extracted with ethyl acetate, and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated to dryness. obtained in 57% yield as an oil using 2-fluoro-4-methylpyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (dichloromethane). h nmr (cdcl3) : 1.41 (t, 3h, j = 7.0), 2.41 (s, 3h), 2.56 (s, 3h), 3.75 (s, 2h), 4.36 (q, 2h, j = 7.0), 6.90 (m, 1h), 7.18 (m, 1h), 7.28 (m, 4h), 7.59 (m, 1h), 8.22 (m, 1h). c nmr (cdcl3) : 13.2, 14.9, 21.2, 27.8, 64.2, 106.7, 115.6, 121.0, 125.7, 128.2, 128.3, 139.5, 141.0, 147.0, 149.3, 154.0, 162.3. obtained in 39% yield as an oil using 2-fluoro-3-methylpyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (dichloromethane). h nmr (cdcl3) : 1.41 (t, 3h, j = 7.0), 2.52 (s, 3h), 2.59 (s, 3h), 3.76 (s, 2h), 4.35 (q, 2h, j = 7.0), 6.92 (m, 1h), 7.19 (m, 1h), 7.28 (m, 4h), 7.59 (m, 2h). c nmr (cdcl3) : 13.3, 14.9, 24.1, 27.8, 64.2, 106.6, 111.8, 118.9, 125.7, 128.2, 128.3, 138.2, 139.4, 141.1, 153.3, 156.4, 162.2. obtained in 39% yield using 2-fluoro-6-methylpyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (dichloromethane) as a wax. h nmr (cdcl3) : 1.38 (t, 3h, j = 7.0), 2.11 (s, 3h), 2.30 (s, 3h), 3.77 (s, 2h), 4.29 (q, 2h, j = 7.0), 7.19 (m, 2h), 7.28 (m, 4h), 7.66 (m, 1h), 8.38 (m, 1h). c nmr (cdcl3) : 10.6, 14.9, 17.9, 28.0, 64.2, 103.9, 123.1, 125.7, 128.2, 128.3, 130.7, 138.8, 140.3, 141.1, 146.1, 151.3, 161.9. obtained in 74% yield as an oil, using 2,3-difluoropyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (dichloromethane ethanol from 100/0 to 98/2). h nmr (cdcl3) : 1.40 (t, 3h, j = 7.1), 2.20 (s, 3h), 3.77 (s, 2h), 4.35 (q, 2h, j = 7.1), 7.19 (m, 1h), 7.28 (m, 5h), 7.57 (m, 1h), 8.37 (m, 1h). c nmr (cdcl3) : 10.7, 14.9, 27.9, 64.3, 105.6, 123.7, 125.5 (j = 18 hz) ; 125.8, 128.3, 128.32, 139.5, 140.7, 141.1, 144.1, 152.8 (j = 273 hz) ; 163.1. hrms calcd for c18h18fn3o + h : 312.1512. found : 312.1503. obtained in 62% yield as a solid, using 2,6-difluoropyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (cyclohexane dichloromethane 2/1). h nmr (cdcl3) : 1.41 (t, 3h, j = 7.0), 2.62 (s, 3h), 3.74 (s, 2h), 4.35 (q, 2h, j = 7.0), 6.64 (m, 1h), 7.20 (m, 1h), 7.27 (m, 4h), 7.66 (m, 1h), 7.80 (m, 1h). c nmr (cdcl3) : 13.5, 14.8, 27.7, 64.2, 103.4 (j = 36 hz) ; 107.9, 110.6, 125.9, 128.2, 128.3, 104.0, 140.6, 142.3, 152.3, 161.5 (j = 237 hz) ; 162.7. obtained in 47% yield as a white powder, using 2-chloro-5-(trifluoromethyl)pyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (cyclohexane dichloromethane 4/1 to 2/1). h nmr (cdcl3) : 1.43 (t, 3h, j = 7.1), 2.65 (s, 3h), 3.75 (s, 2h), 4.37 (q, 2h, j = 7.1), 7.22 (m, 1h), 7.28 (m, 4h), 7.93 (m, 2h), 8.61 (m, 1h). c nmr (cdcl3) : 13.9, 14.8, 27.6, 64.3, 108.7, 113.6, 121.7 (j = 33 hz) ; 123.9 (j = 271 hz) ; 125.9, 128.2, 128.4, 135.0, 140.4, 140.5, 144.6, 156.2, 163.0. hrms calcd for c19h18f3n3o + h : 362.1480. found : 362.1449. obtained in 89% yield as an oil, using 2-fluoro-6-(trifluoromethyl)pyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (cyclohexane dichloromethane 5/1). h nmr (cdcl3) : 1.42 (t, 3h, j = 7.1), 2.65 (s, 3h), 3.74 (s, 2h), 4.35 (q, 2h, j = 7.1), 7.19 (m, 5h), 7.39 (d, 1h, j = 8.4), 7.86 (t, 1h, j = 8.4), 8.03 (d, 1h, j = 8.4). c nmr (cdcl3) : 8.9, 10.0, 22.9, 59.5, 103.6, 110.4, 116.6 (273 hz) ; 121.1, 123.4, 123.6, 134.4, 134.7, 135.7, 135.9, 140.8 (36 hz) ; 149.1, 158.0. hrms calcd for c19h18f3n3o + h : 362.1480. found : 362.1457. obtained in 40% yield as a white powder using 2,5-dichloropyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (cyclohexane dichloromethane 4/1). h nmr (cdcl3) : 1.42 (t, 3h, j = 7.1), 2.57 (s, 3h), 3.74 (s, 2h), 4.34 (q, 2h, j = 7.1), 7.19 (m, 1h), 7.27 (m, 4h), 7.68 (dd, 1h, j = 2.5 and 8.8), 7.76 (d, 1h, j = 8.8), 8.30 (d, 1h, j = 2.5). c nmr (cdcl3) : 13.4, 14.8, 27.7, 64.2, 107.5, 115.5, 125.8, 126.9, 128.2, 128.3, 137.7, 139.7, 140.7, 145.7, 152.2, 162.5. obtained in 44% yield as a solid using 5-bromo-2-fluoropyridine in dimethylformamide at 130 c for 12 h and a chromatography over silica gel (cyclohexane / dichloromethane 2/1) followed by concentration under high vacuum. h nmr (cdcl3) : 1.41 (t, 3h, j = 7.0), 2.57 (s, 3h), 3.74 (s, 2h), 4.34 (q, 2h, j = 7.0), 7.19 (m, 1h), 7.28 (m, 4h), 7.71 (m, 1h), 7.81 (m, 1h), 8.38 (m, 1h). c nmr (cdcl3) : 13.4, 14.8, 27.7, 64.3, 107.6, 115.0, 116.0, 125.8, 128.2, 128.3, 139.7, 140.5, 140.7, 147.9, 152.6, 162.5. obtained in a 33% yield as an oil using 5-bromo-2,3-difluoropyridine in acetonitrile at 180 c for 2 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3). h nmr (cdcl3) : 1.40 (t, 3h, j = 7.1), 2.22 (s, 3h), 3.76 (s, 2h), 4.34 (q, 2h, j = 7.1), 7.20 (m, 1h), 7.28 (m, 4h), 7.74 (m, 1h), 8.40 (d, 1h, j = 2.0). c nmr (cdcl3) : 10.9, 14.8, 27.9, 64.3, 106.3, 117.1, 125.9, 128.3, 128.31, 128.5 (21 hz) ; 139.6, 140.0, 140.5, 144.8, 151.9 (270 hz) ; 163.2. hrms calcd for c18h17brn3fo + h : 390.0617. found : 390.0621. obtained in a 62% yield as solid using 5-bromo-2-fluoro-3-methylpyridine in acetonitrile at 180 c for 3 h and a chromatography over silica gel (cyclohexane / ethyl acetate from 98/2 to 97/3). h nmr (cdcl3) : 1.39 (t, 3h, j = 7.3), 2.15 (s, 3h), 2.33 (s, 3h), 3.76 (s, 2h), 4.29 (q, 2h, j = 7.3), 7.20 (m, 1h), 7.27 (m, 4h), 7.80 (d, 1h, j = 2.4), 8.41 (d, 1h, j = 2.4). c nmr (cdcl3) : 10.8, 14.9, 18.1, 27.9, 64.2, 104.6, 119.0, 125.8, 128.2, 128.3, 132.3, 139.0, 140.9, 142.6, 146.8, 150.0, 162.1. obtained in 47% yield as a solid using 6-chloronicotinonitrile in dimethylformamide at 150 c for 30 min and a chromatography over silica gel (cyclohexane / dichloromethane 1/2). h nmr (cdcl3) : 1.44 (t, 3h, j = 7.0), 2.64 (s, 3h), 3.74 (s, 2h), 4.35 (q, 2h, j = 7.0), 7.25 (m, 5h), 7.93 (m, 2h), 8.60 (m, 1h). c nmr (cdcl3) : 14.1, 14.7, 27.6, 64.4, 103.9, 109.7, 113.6, 117.3, 126.0, 128.2, 128.4, 140.2, 140.6, 140.8, 151.1, 155.7, 163.4. obtained in 19% yield as a solid using methyl 6-chloronicotinate in dimethylformamide at 150 c for 30 min and a chromatography over silica gel (cyclohexane / ethyl acetate from 95/5 to 85/15). h nmr (cdcl3) : 1.43 (t, 3h, j = 7.0), 2.65 (s, 3h), 3.74 (s, 2h), 3.95 (s, 3h), 4.36 (q, 2h, j = 7.0), 7.18 (m, 1h), 7.27 (m, 4h), 7.88 (m, 1h), 8.30 (m, 1h), 8.97 (m, 1h). c nmr (cdcl3) : 14.0, 14.8, 27.6, 52.2, 64.3, 108.7, 113.2, 121.2, 125.9, 128.2, 128.3, 139.0, 140.5, 140.6, 149.5, 156.5, 163.0, 165.8. obtained in 15% yield as a solid using methyl 1-(6-bromopyridin-3-yl)ethanone at 150 c for 30 min in dimethylformamide and a chromatography over silica gel (cyclohexane / ethyl acetate 9/1). h nmr (cdcl3) : 1.42 (t, 3h, j = 7.1), 2.63 (s, 3h), 2.66 (s, 3h), 3.75 (s, 2h), 4.37 (q, 2h, j = 7.1), 7.19 (m, 1h), 7.27 (m, 4h), 7.89 (m, 1h), 8.26 (m, 1h), 8.93 (m, 1h). c nmr (cdcl3) : 14.0, 14.8, 26.5, 27.7, 64.3, 109.0, 113.5, 125.9, 128.0, 128.2, 128.3, 137.5, 140.5, 140.6, 148.8, 156.5, 163.1, 195.7. obtained in 17% yield as an oil using 5-cyclopropyl-2,3-difluoropyridine at 140 c for 4 h in acetonitrile after a chromatography over silica gel (cyclohexane / ethyl acetate from 97/3 to 4/1) followed by concentration under high vacuum. h nmr (cdcl3) : 0.76 (m, 2h), 1.11 (m, 2h), 1.38 (t, 3h, j = 7.2), 1.98 (m, 1h), 2.14 (s, 3h), 3.76 (s, 2h), 4.33 (q, 2h, j = 7.2), 7.18 (m, 2h), 7.29 (m, 4h), 8.18 (d, 1h, j = 1.7). c nmr (cdcl3) : 9.6, 10.5 (2 hz) ; 12.6, 14.9, 27.9, 64.9, 105.0, 121.8 (19 hz) ; 125.7, 128.2, 128.3, 138.3 (11 hz) ; 139.4, 140.8, 141.6 (6 hz) ; 142.4 (5 hz) ; 153.0 (260 hz) ; 162.9. obtained in 18% yield as a solid using 2-chloro-5-cyclopropylnicotinonitrile at 160 c for 4 h in acetonitrile after a chromatography over silica gel (cyclohexane / dichloromethane from 2/1 to 0/1). h nmr (cdcl3) : 0.76 (m, 2h), 1.11 (m, 2h), 1.43 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.47 (s, 3h), 3.74 (s, 2h), 4.41 (q, 2h, j = 7.2), 7.18 (m, 1h), 7.27 (m, 4h), 7.67 (d, 1h, j = 2.5), 8.34 (d, 1h, j = 2.5). c nmr (cdcl3) : 9.1, 12.2, 12.6, 14.8, 27.7, 64.9, 101.3, 108.1, 116.8, 125.9, 128.2, 128.3, 135.7, 139.5, 140.4, 140.9, 149.3, 150.7, 162.4. obtained in 67% yield as an oil, using 2-(6-fluoropyridin-3-yl)propan-2-ol (5 t) at 180 c for 6 h in acetonitrile and a chromatography over silica gel (cyclohexane / ethyl acetate 4/1). h nmr (cdcl3) : 1.41 (t, 3h, j = 7.1), 1.60 (s, 6h), 2.12 (s, 1h), 2.57 (s, 3h), 3.76 (s, 2h), 4.36 (q, 2h, j = 7.1), 7.25 (m, 1h), 7.28 (m, 4h), 7.71 (dd, 1h, j = 0.8 and 8.7), 7.85 (dd, 1h, j = 2.5 and 8.7), 8.47 (dd, 1h, j = 0.8 and 2.5). c nmr (cdcl3) : 13.1, 14.9, 27.7, 31.6, 64.2, 71.2, 106.7, 114.6, 125.8, 128.2, 128.3, 134.8, 139.4, 140.2, 140.9, 143.7, 152.6, 163.2. obtained in 17% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.73 (m, 2h), 1.04 (m, 2h), 1.38 (t, 3h, j = 7.2), 1.93 (m, 1h), 2.54 (s, 3h), 4.35 (q, 2h, j = 7.2), 7.04 (m, 3h), 7.30 (m, 2h), 7.42 (dd, 1h, j = 2.4 and 8.5), 7.69 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.6, 11.9, 12.5, 14.8, 64.8, 114.1, 115.1, 121.9, 124.8, 129.4, 133.3, 135.2, 135.6, 145.4, 151.8, 155.4, 158.6. obtained in 41% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.73 (m, 2h), 1.03 (m, 2h), 1.37 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.55 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.97 (m, 3h), 7.12 (m, 1h), 7.41 (dd, 1h, j = 2.5 and 8.6), 7.68 (d, 1h, j = 8.6), 8.19 (d, 1h, j = 2.5). c nmr (cdcl3) : 8.7, 11.8, 12.5, 14.8, 64.8, 114.1, 116.1, 116.4 (18 hz) ; 123.3 (6 hz) ; 124.0 (3 hz) ; 124.4, 133.3, 135.2, 135.7, 145.5, 146.4 (11 hz) ; 151.8, 152.1 (248 hz) ; 155.1. obtained in 70% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.37 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.54 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.89 (m, 1h), 6.96 (m, 2h), 7.15 (m, 1h), 7.42 (m, 2h), 7.69 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.7, 11.8, 12.6, 14.8, 64.8, 114.1, 115.0, 122.3, 122.7, 124.5, 127.5, 130.4, 133.3, 135.2, 135.8, 145.5, 151.8, 154.1, 155.1. obtained in 50% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.37 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.53 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.89 (m, 2h), 7.19 (m, 1h), 7.41 (dd, 1h, j = 2.5 and 8.5), 7.59 (dd, 1h, j = 1.6 and 7.8), 7.68 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.5). c nmr (cdcl3) : 8.7, 11.9, 12.6, 14.8, 64.8, 111.2, 114.1, 114.9, 123.2, 124.6, 128.3, 133.3, 133.4, 135.2, 135.8, 145.5, 151.8, 155.1, 155.2. obtained in 44% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.74 (m, 2h), 1.04 (m, 2h), 1.36 (t, 3h, j = 7.2), 1.91 (m, 1h), 2.51 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.96 (m, 1h), 7.08 (m, 1h), 7.43 (m, 2h), 7.65 (m, 2h), 8.20 (d, 1h, j = 2.5). c nmr (cdcl3) : 8.7, 11.6, 12.5, 14.8, 64.9, 114.2, 114.6, 118.6 (31 hz) ; 121.4, 123.6 (272 hz) ; 123.9, 127.0 (5 hz) ; 133.1, 133.4, 135.2, 135.9, 145.5, 151.7, 155.1, 153.3 (2 hz). obtained in 55% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.73 (m, 2h), 1.03 (m, 2h), 1.36 (t, 3h, j = 7.2), 1.93 (m, 1h), 2.54 (s, 3h), 4.36 (q, 2h, j = 7.2), 7.18 (m, 1h), 7.20 (m, 2h), 7.40 (m, 2h), 7.70 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 11.8, 12.5, 14.7, 64.8, 112.2 (4 hz) ; 114.1, 118.4, 118.7 (4 hz) ; 123.9 (273 hz) ; 124.0, 130.0, 131.9 (33 hz) ; 133.3, 135.2, 135.8, 145.5, 151.8, 155.0, 158.6. obtained in 53% yield as a solid using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.73 (m, 2h), 1.04 (m, 2h), 1.37 (t, 3h, j = 7.2), 1.94 (m, 1h), 2.52 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.9 (d, 2h, j = 8.6), 7.42 (dd, 1h, j = 2.5 and 8.5), 7.57 (d, 2h, j = 8.6), 7.69 (d, 2h, j = 8.5), 8.20 (d, 1h, j = 2.5). c nmr (cdcl3) : 8.7, 11.8, 12.5, 14.7, 64.8, 114.1, 115.2, 123.9 124.3, (38 hz) ; 124.4 (272 hz) ; 126.9 (4 hz) ; 131.3, 135.2, 135.9, 145.5, 151.7, 155.0, 161.0. obtained in 50% yield as a solid using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.37 (t, 3h, j = 7.2), 1.93 (m, 1h), 2.52 (s, 3h), 4.34 (q, 2h, j = 7.2), 6.82 (dd, 1h, j = 1.5 and 8.1), 7.08 (t, 1h, j = 8.1), 7.15 (dd, 1h, j = 1.5 and 8.1), 7.40 (dd, 1h, j = 2.5 and 8.5), 7.68 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.5). c nmr (cdcl3) : 8.7, 11.8, 12.5, 14.8, 64.9, 112.9, 114.2, 121.5, 123.6, 124.3, 127.1, 133.3, 133.9, 135.2, 135.9, 145.5, 151.7, 154.9, 155.5. obtained in 43% yield as a solid using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.73 (m, 2h), 1.04 (m, 2h), 1.37 (t, 3h, j = 7.1), 1.93 (m, 1h), 2.54 (s, 3h), 4.34 (q, 2h, j = 7.1), 6.89 (d, 1h, j = 2.3), 6.96 (dd, 1h, j = 2.3 and 8.5), 7.33 (d, 1h, j = 8.5), 7.42 (dd, 1h, j = 2.5 and 8.5), 7.69 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.5). c nmr (cdcl3) : 8.7, 11.8, 12.6, 14.8, 64.9, 114.1, 115.6, 120.8, 122.8, 124.0, 130.9, 133.1, 133.3, 135.2, 135.9, 145.5, 151.7, 154.5, 154.7. obtained in 48% yield as an oil using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.74 (m, 2h), 1.05 (m, 2h), 1.38 (t, 3h, j = 7.4), 1.93 (m, 1h), 2.52 (s, 3h), 4.34 (q, 2h, j = 7.4), 6.92 (d, 1h, j = 1.8), 7.03 (t, 1h, j = 1.8), 7.42 (dd, 1h, j = 2.3 and 8.5), 7.69 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 11.8, 12.6, 14.7, 64.8, 114.1, 114.3, 122.4, 123.7, 133.3, 135.2, 135.4, 135.9, 145.5, 151.7, 154.7, 159.5. obtained in 58% yield as a solid using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.75 (m, 2h), 1.03 (m, 2h), 1.33 (d, 6h, j = 6.0), 1.92 (m, 1h), 2.54 (s, 3h), 4.98 (sept, 1h, j = 6.0), 6.98 (m, 3h), 7.12 (m, 1h), 7.40 (m, 1h), 7.68 (m, 1h), 8.18 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.6, 11.8, 12.5, 22.1, 72.1, 114.2, 116.3, 116.4 (18 hz) ; 122.3, 124.0, 125.1, 133.0, 135.1, 135.6, 145.4, 146.4 (10 hz) ; 151.9, 152.3 (248 hz) ; 154.5. obtained in 57% yield as an oil, using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.35 (d, 6h, j = 6.2), 1.92 (m, 1h), 2.52 (s, 3h), 5.00 (sept, 1h, j = 6.2), 6.73 (m, 2h), 6.82 (m, 1h), 7.22 (m, 1h), 7.41 (dd, 1h, j 2.4 and 8.5), 7.70 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.7, 11.9, 12.5, 21.1, 72.1, 103.1 (25 hz) ; 108.8 (21 hz) ; 111.0 (3 hz) ; 114.1, 124.9, 130.1 (10 hz) ; 133.1, 135.1, 135.7, 145.4, 151.9, 154.5, 160.0 (10 hz) ; 163.6 (245 hz). obtained in 50% yield as a solid, using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.34 (d, 6h, j = 6.2), 1.93 (m, 1h), 2.52 (s, 3h), 4.98 (sept, 1h, j = 6.2), 6.97 (m, 4h), 7.40 (dd, 1h, j = 2.3 and 8.5), 7.68 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.6, 11.9, 12.5, 21.1, 72.0, 114.1, 115.6 (23 hz) ; 116.2 (8 hz) ; 125.6, 133.0, 135.1, 135.6, 145.4, 151.9, 154.7 (3 hz) ; 158.0 (239 hz). hrms calcd for c21h22fn3o2 + h : 368.1774. found : 368.1759. obtained in 55% yield as an oil, using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.34 (d, 6h, j = 6.2), 1.92 (m, 1h), 2.55 (s, 3h), 4.99 (sept, 1h, j = 6.2), 6.71 (m, 1h), 6.84 (m, 1h), 6.91 (m, 1h), 7.41 (dd, 1h, j 2.3 and 8.5), 7.68 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 11.8, 12.5, 21.1, 72.2, 110.2 (18 hz) ; 111.2 (3 hz) ; 114.2, 122.8 (5 and 9 hz) ; 124.9, 133.0, 135.2, 135.8, 141.1 (15 and 249 hz) ; 145.5, 148.0 (3 and 8 hz) ; 151.5 (10 and 247 hz) ; 151.8, 154.2. obtained in 54% yield as an oil, using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.33 (d, 6h, j = 6.2), 1.93 (m, 1h), 2.55 (s, 3h), 4.98 (sept, 1h, j = 6.2), 6.74 (m, 1h), 6.91 (m, 2h), 7.42 (dd, 1h, j 2.3 and 8.5), 7.67 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 11.7, 12.5, 22.1, 72.1, 104.8 (22 and 28 hz) ; 110.3 (4 and 22 hz) ; 114.2, 116.9 (2 and 10 hz) ; 125.4, 132.9, 135.2, 135.7, 143.0 (4 and 11 hz) ; 145.4, 151.8, 151.9 (12 and 242 hz) ; 154.3, 157.2 (10 and 242 hz). hrms calcd for c21h21f2n3o2 + h : 386.1680. found : 386.1667. obtained in 55% yield as an oil, using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by concentration under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.04 (m, 2h), 1.35 (d, 6h, j = 6.2), 1.93 (m, 1h), 2.55 (s, 3h), 5.00 (sept, 1h, j = 6.2), 6.67 (m, 2h), 7.08 (m, 1h), 7.42 (dd, 1h, j 2.3 and 8.5), 7.68 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 11.8, 12.5, 22.1, 72.2, 104.8 (28 hz) ; 108.2 (6 and 24 hz) ; 114.2, 116.9 (10 and 20 hz) ; 124.5, 133.1, 135.2, 135.8, 145.4, 147.1 (22 hz) ; 148.5 (4 and 243 hz) ; 151.8, 154.2, 158.6 (3 and 242 hz). obtained in 53% yield as an oil, using 5-cyclopropyl-2-fluoropyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 98/2 to 97/3) followed by extensive drying under high vacuum. h nmr (cdcl3) : 0.72 (m, 2h), 1.01 (m, 2h), 1.25 (d, 6h, j = 6.2), 1.91 (m, 1h), 2.63 (s, 3h), 4.89 (sept, 1h, j = 6.2), 6.88 (m, 2h), 7.01 (m, 1h), 7.37 (m, 1h), 7.62 (d, 1h, j = 8.5), 8.18 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.6, 11.6, 12.5, 21.9, 71.9, 111.9 (6 and 16 hz) ; 114.2, 123.4 (9 hz) ; 129.1, 131.0, 134.7 (13 hz) ; 135.0, 135.4, 145.4, 152.0, 153.4, 155.7 (4 and 250 hz). obtained in 57% yield as a solid using 3-chloro-6-cyclopropylpyridazine (9) in acetonitrile at 180 c for 2 h after a chromatography over silica gel (cyclohexane / ethyl acetate 6/1). h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.36 (t, 3h, j = 7.0), 2.17 (m, 1h), 2.66 (s, 3h), 4.34 (q, 2h, j = 7.0), 6.93 (m, 1h), 7.00 (m, 2h), 7.16 (m, 1h), 7.34 (d, 1h, j = 9.2), 7.95 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.4, 14.7, 15.4, 64.9, 116.1, 116.6 (17 hz) ; 118.9, 122.6 (7 hz) ; 124.1 (4 hz) ; 125.5, 127.1, 134.1, 146.1 (11 hz) ; 152.2 (246 hz) ; 155.5, 156.1, 161.6. obtained in 62% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.14 (m, 2h), 1.22 (m, 2h), 1.36 (t, 3h, j = 7.2), 2.15 (m, 1h), 2.65 (s, 3h), 4.34 (q, 2h, j = 7.2), 6.87 (m, 1h), 6.97 (m, 1h), 7.15 (ddd, 1h, j = 1.8, 7.4 and 8.6), 7.32 (d, 1h, j = 9.2), 7.41 (dd, 1h, j = 1.6 and 7.9), 7.94 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.4, 14.7, 15.4, 64.9, 114.9, 118.8, 122.4, 122.9, 125.5, 127.1, 127.6, 130.5, 134.2, 153.9, 155.5, 156.1, 161.6. obtained in 62% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.36 (t, 3h, j = 7.2), 2.17 (m, 1h), 2.64 (s, 3h), 4.34 (q, 2h, j = 7.2), 6.81 (dd, 2h, j = 1.4 and 8.3), 6.91 (m, 1h), 7.20 (m, 1h), 7.34 (d, 1h, j = 9.2), 7.59 (dd, 1h, j = 1.5 and 7.9), 7.94 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.4, 14.7, 15.4, 65.0, 111.2, 114.8, 118.8, 123.4, 125.6, 127.1, 128.3, 133.5, 134.2, 154.8, 155.5, 156.1, 161.6. obtained in 65% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.35 (t, 3h, j = 7.2), 2.16 (m, 1h), 2.63 (s, 3h), 4.33 (q, 2h, j = 7.2), 6.94 (d, 1h, j = 8.3), 7.10 (m, 1h), 7.34 (d, 1h, j = 9.2), 7.43 (m, h), 7.64 (m, 1h), 7.94 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.2, 14.6, 15.4, 65.0, 114.5, 118.7 (31 hz) ; 118.8, 121.6, 127.9, 126.1 (274 hz) ; 127.0 (3 hz) ; 127.1, 133.1, 134.3, 155.5, 156.0 (20 hz) ; 156.1, 161.7. obtained in 64% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.36 (t, 3h, j = 7.0), 2.17 (m, 1h), 2.62 (s, 3h), 4.35 (q, 2h, j = 7.0), 7.19 (m, 1h), 7.25 (m, 1h), 7.30 (m, 1h), 7.35 (d, 1h, j = 9.2), 7.41 (m, 1h), 7.96 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.4, 14.6, 15.4, 64.9, 112.2 (4 hz) ; 118.5, 118.8 (4 hz) ; 123.8 (272 hz) ; 125.0, 127.1, 130.1, 132.0 (33 hz) ; 134.2, 155.5, 155.9, 158.4, 161.7. obtained in 57% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.37 (t, 3h, j = 7.0), 2.17 (m, 1h), 2.64 (s, 3h), 4.35 (q, 2h, j = 7.0), 7.8 (m, 2h), 7.35 (d, 1h, j = 9.2), 7.57 (m, 2h), 7.96 (d, 2h, j = 9.2). c nmr (cdcl3) : 10.4, 12.4, 14.6, 15.4, 64.9, 115.2, 118.8, 124.3, (270 hz) ; 124.5 (33 hz) ; 124.9, 127.0 (4 hz) ; 127.1, 134.2, 155.5, 155.9, 160.7, 161.7. obtained in 65% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.35 (t, 3h, j = 7.2), 2.16 (m, 1h), 2.64 (s, 3h), 4.33 (q, 2h, j = 7.2), 6.78 (dd, 1h, j = 1.5 and 8.2), 7.08 (t, 1h, j = 8.2), 7.14 (dd, 1h, j = 1.6 and 8.2), 7.34 (d, 1h, j = 9.2), 7.93 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.4, 12.4, 14.7, 15.4, 65.0, 112.8, 118.8, 121.6, 123.8, 125.3, 127.1, 127.2, 134.0, 134.2, 155.2, 155.5, 155.8, 161.8. obtained in 50% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.37 (t, 3h, j = 7.2), 2.16 (m, 1h), 2.66 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.85 (d, 1h, j = 2.2), 6.96 (dd, 1h, j = 2.2 and 8.4), 7.33 (d, 1h, j = 8.4), 7.35 (d, 1h, j = 9.2), 7.95 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.4, 12.4, 14.7, 15.4, 65.0, 115.4, 118.8, 120.9, 123.1, 124.9, 127.2, 131.0, 133.1, 134.2, 154.3, 155.6, 155.65, 161.8. obtained in 55% yield as a solid the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.23 (m, 2h), 1.38 (t, 3h, j = 7.2), 2.17 (m, 1h), 2.63 (s, 3h), 4.35 (q, 2h, j = 7.2), 6.90 (d, 1h, j = 1.8), 7.04 (t, 1h, j = 1.8), 7.35 (d, 1h, j = 9.2), 7.94 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.4, 12.4, 14.7, 15.4, 65.0, 114.3, 118.8, 122.6, 124.7, 127.1, 134.2, 135.5, 155.5, 155.7, 159.2, 161.8. obtained in 67% yield as a solid the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.33 (d, 6h, j = 6.2), 2.16 (m, 1h), 2.66 (s, 3h), 4.97 (sept, 1h, j = 6.2), 6.92 (m, 1h), 6.99 (m, 2h), 7.14 (m, 1h), 7.68 (d, 1h, j = 9.2), 7.94 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.3, 15.4, 22.0, 72.3, 116.3, 116.5 (18 hz) ; 118.8, 119.1, 122.6 (7 hz) ; 124.1 (4 hz) ; 126.1, 127.1, 133.9, 146.2 (11 hz) ; 152.2 (247 hz) ; 155.5, 155.6, 161.5. obtained in 67% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.35 (d, 6h, j = 6.2), 2.19 (m, 1h), 2.63 (s, 3h), 4.99 (sept, 1h, j = 6.2), 6.73 (m, 2h), 6.80 (m, 1h), 7.23 (m, 2h), 7.34 (d, 1h, j = 9.2), 7.95 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.4, 15.4, 22.0, 72.3, 103.1 (26 hz) ; 109.0 (21 hz) ; 111.0 (3 hz) ; 118.9, 125.8, 130.2 (9 hz) ; 134.0, 155.5, 155.6, 159.6 (10 hz) ; 161.6, 163.6 (246 hz) (one signal missing). hrms calcd for c20h21fn3o2 + h : 369.1727. found : 369.1769. obtained in 67% yield as an oil using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.33 (d, 6h, j = 6.2), 2.17 (m, 1h), 2.63 (s, 3h), 4.97 (sept, 1h, j = 6.2), 6.96 (m, 4h), 7.33 (d, 1h, j = 9.2), 7.94 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.4, 15.4, 22.0, 72.3, 115.8 (23 hz) ; 116.3 (8 hz) ; 118.8, 126.5, 127.1, 133.9, 154.4 (2 hz) ; 155.5, 155.6, 158.1 (240 hz) ; 161.5. hrms calcd for c20h21fn4o2 + h : 369.1727. found : 369.1712. obtained in 52% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.15 (m, 2h), 1.22 (m, 2h), 1.33 (d, 6h, j = 6.2), 2.18 (m, 1h), 2.63 (s, 3h), 4.89 (sept, 1h, j = 6.2), 6.70 (m, 1h), 6.85 (m, 1h), 6.92 (m, 1h), 7.33 (d, 1h, j = 9.2), 7.93 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.3, 15.4, 22.0, 72.4, 110.5 (17 hz) ; 111.2 (3 hz) ; 118.8, 122.9 (5 and 8 hz) ; 125.9, 127.1, 133.9, 141.1 (14 and 249 hz) ; 147.7 (2 and 7 hz) ; 151.5 (10 and 247 hz) ; 155.2, 155.5, 161.7. obtained in 69% yield as an oil using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.13 (m, 2h), 1.18 (m, 2h), 1.33 (d, 6h, j = 6.2), 2.16 (m, 1h), 2.66 (s, 3h), 4.96 (sept, 1h, j = 6.2), 6.72 (m, 1h), 6.80 (m, 3h), 7.33 (d, 1h, j = 9.2), 7.92 (d, 1h, j = 9.2). c nmr (cdcl3) : 10.3, 12.3, 15.4, 22.0, 72.3, 104.9 (22 and 27 hz) ; 110.3 (4 and 23 hz) ; 117.0 (2 and 9 hz) ; 118.8, 126.5, 133.7, 142.6 (3 and 10 hz) ; 151.9 (12 and 250 hz) ; 155.3, 155.5, 157.4 (9 and 244 hz) ; 161.6 (one signal missing). obtained in 77% yield as a solid using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.16 (m, 2h), 1.23 (m, 2h), 1.36 (d, 6h, j = 6.2), 2.16 (m, 1h), 2.67 (s, 3h), 5.00 (sept, 1h, j = 6.2), 6.68 (m, 2h), 7.07 (m, 2h), 7.34 (d, 1h, j = 9.3), 7.95 (d, 1h, j = 9.3). c nmr (cdcl3) : 10.4, 12.3, 15.4, 22.0, 72.4, 104.1 (28 hz) ; 108.5 (7 and 24 hz) ; 116.7 (10 and 20 hz) ; 118.9, 125.6, 127.1, 134.0, 146.7 (10 and 12 hz) ; 148.5 (3 and 242 hz) ; 155.1, 155.5, 158.5 (2 and 243 hz) ; 161.7. obtained in 22% yield as an oil, using the procedure described for the preparation of compound 10b. h nmr (cdcl3) : 1.11 (m, 2h), 1.21 (m, 2h), 1.26 (d, 6h, j = 6.2), 2.15 (m 1h), 2.75 (s, 3h), 4.88 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.02 (m, 1h), 7.29 (d, 1h, j = 9.1), 7.88 (d, 1h, j = 9.1). c nmr (cdcl3) : 10.2, 12.1, 15.4, 21.9, 72.1, 111.9 (6 and 17 hz) ; 118.8, 123.6 (9 hz) ; 126.9, 129.8, 131.8, 134.5 (14 hz) ; 154.4, 155.5 (4 and 250 hz) ; 155.7, 161.3. obtained in 66% yield as an oil, using 2-fluoropyridine in acetonitrile at 180 c for 6 h, and a chromatography over silica gel (cyclohexane / ethyl acetate 95/5). h nmr (cdcl3) : 1.26 (d, 6h, j = 6.2), 2.68 (s, 3h), 4.91 (sept, 1h, j = 6.2), 7.01 (m, 2h), 7.06 (m, 2h), 7.72 (m, 2h), 8.36 (m, 1h). c nmr (cdcl3) : 11.9, 21.9, 72.0, 111.9 (6 and 17 hz) ; 114.3, 119.6, 123.4 (9 hz) ; 129.4, 131.3, 134.7 (14 hz) ; 137.9, 147.2, 153.7, 154.1, 155.6 (5 and 250 hz). hrms calcd for c18h17f2n3o2 + h : 346.1367. found : 346.1409. obtained in 34% yield as an oil, using 2-fluoro-5-methylpyridine in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3). h nmr (cdcl3) : 1.26 (d, 6h, j = 6.2), 2.33 (s, 3h), 2.64 (s, 3h), 4.90 (sept, 1h, j = 6.2), 6.92 (m, 2h), 7.01 (m, 1h), 7.54 (m, 1h), 7.64 (d, 1h, j = 8.4), 8.18 (m, 1h). c nmr (cdcl3) : 11.6, 17.7, 21.9, 71.9, 111.9 (6 and 17 hz) ; 114.2, 123.4 (9 hz) ; 129.1, 129.2, 131.0, 134.7 (14 hz) ; 138.7, 147.1, 152.0, 153.4, 155.7 (5 and 250 hz). obtained in 64% yield as a solid, using 2-chloro-5-(trifluoromethyl)pyridine in acetonitrile at 180 c for 4 h after a chromatography over silica gel (cyclohexane / dichloromethane 8/1). h nmr (cdcl3) : 1.27 (d, 6h, j = 6.1), 2.72 (s, 3h), 4.93 (sept, 1h, j = 6.1), 6.92 (m, 2h), 7.05 (m, 1h), 7.91 (m, 2h), 8.61 (m, 1h). c nmr (cdcl3) : 12.3, 21.8, 72.0, 111.9 (6 and 17 hz) ; 113.0, 121.9 (33 hz) ; 121.6 (9 hz) ; 123.9 (272 hz) ; 130.3, 132.0, 134.4 (13 hz) ; 134.9 (3 hz), 144.7 (4 hz) ; 154.6, 155.6 (5 and 250 hz) ; 156.4. hrms calcd for c19h16f5n3o2 + h : 414.1241. found : 414.1207. obtained in 46% yield as an oil, using 5-cyclopropyl-2,3-difluoropyridine (5r) in acetonitrile at 180 c for 3 h and a first chromatography over silica gel (cyclohexane / ethyl acetate 7/1) and a second one over silica gel (dichloromethane). h nmr (cdcl3) : 0.76 (m, 2h), 1.11 (m, 2h), 1.22 (d, 6h, j = 6.1), 1.97 (m, 1h), 2.27 (s, 3h), 4.87 (sept, 1h, j = 6.1), 6.82 (m, 3h), 7.16 (m, 1h), 8.16 (d, 1h, j = 2.0). c nmr (cdcl3) : 9.2, 9.6, 12.6, 21.9, 71.9, 111.9 (6 and 16 hz) ; 121.9 (18 hz) ; 123.5 (9 hz) ; 128.3, 131.0, 134.7 (14 hz) ; 138.1 (10 hz) ; 141.6, 142.3, 152.9 (263 hz) ; 154.1, 155.8 (5 and 250 hz). hrms calcd for c21h20f3n3o2 + h : 404.1586. found : 404.1527. obtained in 96% yield as a solid, using 2-chloro-5-cyclopropylnicotinonitrile in acetonitrile (5s) at 150 c for 40 min and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3). h nmr (cdcl3) : 0.76 (m, 2h), 1.12 (m, 2h), 1.28 (d, 6h, j = 6.2), 1.94 (m, 1h), 2.58 (s, 3h), 4.94 (sept, 1h, j = 6.2), 6.94 (m, 2h), 7.05 (m, 1h), 7.67 (d, 1h, j = 2.4), 8.34 (d, 1h, j = 2.4). c nmr (cdcl3) : 9.0, 11.4, 12.2, 21.8, 72.8, 100.6, 111.9 (6 and 16 hz) ; 116.7, 123.7 (9 hz) ; 130.0, 131.1, 134.3 (14 hz) ; 135.7, 141.1, 149.3, 152.7, 153.9, 155.7 (4 and 249 hz). obtained in 79% yield as a solid, using 2-fluoro-5-bromopyridine in acetonitrile at 160 c for 3 h and a chromatography over silica gel (cyclohexane / ethyl acetate 98/2 to 9/1). h nmr (cdcl3) : 1.25 (d, 6h, j = 6.2), 2.65 (s, 3h), 4.89 (sept, 1h, j = 6.2), 6.94 (m, 2h), 7.02 (m, 1h), 7.69 (d, 1h, j = 8.8), 7.80 (dd, 1h, j = 2.6 and 8.8), 8.39 (d, 1h, j = 2.6). c nmr (cdcl3) : 12.0, 21.9, 72.1, 111.9 (6 and 16 hz) ; 115.1, 115.4, 123.5 (9 hz) ; 129.7, 131.5, 134.5 (13 hz) ; 140.4, 147.9, 152.8, 154.0, 155.6 (5 and 250 hz). obtained in 73% yield as a solid, using 5-bromo-2,3-difluoropyridine in acetonitrile at 180 c for 3 h and a chromatography over silica gel (cyclohexane / ethyl acetate 98/2). h nmr (cdcl3) : 1.23 (d, 6h, j = 6.2), 2.35 (s, 3h), 4.86 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.02 (m, 1h), 7.75 (d, 1h, j = 2.1 and 9.1), 8.38 (d, 1h, j = 2.1). c nmr (cdcl3) : 9.6, 21.8, 72.1, 111.9 (6 and 17 hz) ; 117.6 (2 hz) ; 123.7 (9 hz) ; 128.6 (21 hz) ; 129.0, 131.2, 134.5 (14 hz) ; 139.9 (9 hz) ; 144.7 (5 hz) ; 151.7 (270 hz) ; 154.5, 155.7 (4 and 250 hz). hrms calcd for c18h15brf3n3o2 + h : 442.0378. found : 442.0346. obtained in 84% yield as an oil, using 5-bromo-2-fluoro-3-methylpyridine in acetonitrile at 180 c for 3 h and a chromatography over silica gel (cyclohexane / ethyl acetate 98/2). h nmr (cdcl3) : 1.23 (d, 6h, j = 6.2), 2.25 (s, 3h), 2.32 (s, 3h), 4.79 (sept, 1h, j = 6.2), 6.90 (m, 2h), 7.01 (m, 1h), 7.78 (d, 1h, j = 2.3), 8.39 (d, 1h, j = 2.3). c nmr (cdcl3) : 9.5, 18.2, 21.9, 72.0, 111.9 (6 and 17 hz) ; 119.0, 123.5 (9 hz) ; 128.0, 130.7, 132.1, 134.7 (14 hz) ; 142.7, 146.7, 149.7, 153.3, 155.7 (4 and 250 hz). obtained in 52% yield as a solid, using 1-(6-bromopyridin-3-yl)ethanone in acetonitrile at 130 c for 3 h and a chromatography over silica gel (cyclohexane / ethyl acetate 95/5 to 9/1). h nmr (cdcl3) : 1.27 (d, 6h, j = 6.1), 2.63 (s, 3h), 2.74 (s, 3h), 4.93 (sept, 1h, j = 6.1), 6.92 (m, 2h), 7.03 (m, 1h), 7.87 (d, 1h, j = 8.7), 8.25 (dd, 1h, j = 2.5 and 8.7), 8.92 (m, 1h). c nmr (cdcl3) : 12.5, 21.8, 26.5, 72.2, 112.0 (6 and 16 hz) ; 113.0, 123.7 (10 hz) ; 128.2, 130.4, 132.1, 134.3 (13 hz) ; 137.4, 148.8, 154.7, 155.6 (4 and 250 hz) ; 156.7, 195.7. obtained in 68% yield as an oil, using 2-(6-fluoropyridin-3-yl)propan-2-ol (5 t) in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 4/1). h nmr (cdcl3) : 1.25 (d, 6h, j = 6.2), 1.63 (s, 6h), 1.86 (s, 1h), 2.65 (s, 3h), 4.90 (sept, 1h, j = 6.2), 6.90 (m, 2h), 6.99 (m, 1h), 7.70 (dd, 1h, j = 0.7 and 8.6), 8.25 (dd, 1h, j = 2.5 and 8.6), 8.48 (dd, 1h, j = 0.7 and 2.5). c nmr (cdcl3) : 11.8, 21.9, 31.7, 71.3, 72.0, 111.9 (6 and 17 hz) ; 113.8, 123.4 (9 hz) ; 129.3, 131.2, 134.7 (14 hz) ; 134.8, 140.2, 143.7, 152.9, 153.6, 155.6 (4 and 250 hz). obtained in 49% yield as an oil, using 5-ethyl-2-fluoropyridine (17l) in acetonitrile at 180 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by drying under high vacuum. h nmr (cdcl3) : 1.26 (d, 6h, j = 6.2), 1.27 (t, 3h, j = 7.6), 2.64 (s, 3h), 2.65 (q, 2h, j = 7.6), 4.90 (sept, 1h, j = 6.2), 6.92 (m, 2h), 7.00 (m, 1h), 7.56 (dd, 1h, j = 1.9 and 8.5), 7.66 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 1.9). c nmr (cdcl3) : 11.6, 15.4, 21.9, 25.5, 71.9, 111.9 (6 and 17 hz) ; 114.3, 123.4 (9 hz) ; 129.1, 131.0, 134.7 (14 hz) ; 135.4, 137.6, 146.4, 152.2, 153.5, 155.6 (4 and 250 hz). obtained in 34% yield as an oil, using 2,3-difluoro-5-ethylpyridine (17 m) in acetonitrile at 140 c for 4 h and a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by drying under high vacuum. h nmr (cdcl3) : 1.23 (d, 6h, j = 6.2), 1.31 (t, 3h, j = 7.6), 2.28 (s, 3h), 2.74 (q, 2h, j = 7.6), 4.88 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.01 (m, 1h), 7.41 (m, 1h), 8.20 (m, 1h). c nmr (cdcl3) : 9.3, 15.0, 21.9, 25.3, 71.9, 111.9 (6 and 17 hz) ; 123.5 (9 hz) ; 124.8 (17 hz) ; 128.3, 131.1, 134.7 (14 hz) ; 138.5 (11 hz) ; 141.0 (3 hz) ; 143.5 (5 hz) ; 152.8 (260 hz) ; 154.1, 155.8 (4 and 250 hz). hrms calcd for c20h20f3n3o2 + h : 392.1586. found : 392.1572. obtained in 12% yield as an oil, using 2-bromo-5-(1,1-difluoroethyl)pyridine (17n) in acetonitrile at 140 c for 6 h and a chromatography over silica gel (cyclohexane / ethyl acetate from 98.5/1.5 to 9/1). h nmr (cdcl3) : 1.26 (d, 6h, j = 6.2), 1.98 (t, 3h, j = 18), 2.70 (s, 3h), 4.92 (sept, 1h, j = 6.2), 6.93 (m, 2h), 7.02 (m, 1h), 7.84 (m, 2h), 8.50 (s, 1h). c nmr (cdcl3) : 12.1, 21.9, 25.7 (30 hz) ; 72.1, 111.9 (6 and 16 hz) ; 113.3, 121.0 (239 hz) ; 123.5 (9 hz) ; 129.3 (27 hz) ; 129.8, 131.6, 134.5 (14 hz) ; 134.6 (5 hz) ; 144.0 (6 hz) ; 154.2, 155.1, 155.6 (4 and 250 hz). obtained in 59% yield as a white powder, using 2,5-dibromopyrazine in acetonitrile at 120 c for 5 h and a chromatography over silica gel (cyclohexane / dichloromethane from 2/1 to 1/1). h nmr (cdcl3) : 1.26 (d, 6h, j = 6.2), 2.64 (s, 3h), 4.91 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.05 (m, 1h), 8.35 (d, 1h, j = 1.3), 8.87 (d, 1h, j = 1.3). c nmr (cdcl3) : 11.8, 21.8, 72.4, 111.9 (6 and 17 hz) ; 123.8 (9 hz) ; 130.4, 131.8, 133.4, 134.2 (13 hz) ; 134.6, 143.1, 149.1, 154.9, 155.6 (4 and 250 hz). hrms calcd for c17h15brf2n4o2 + h : 425.0425. found : 425.0418. obtained in 32% yield as a solid using from 2-chloro-5-(trifluoromethyl)pyrazine in acetonitrile at 180 c for 4 h after a chromatography over silica gel (cyclohexane / dichloromethane 2/1). h nmr (cdcl3) : 1.27 (d, 6h, j = 6.2), 2.70 (s, 3h), 4.97 (sept, 1h, j = 6.2), 6.92 (m, 2h), 7.07 (m, 2h), 8.60 (s, 1h), 9.21 (s, 1h). c nmr (cdcl3) : 12.1, 21.7, 72.6, 112.0 (6 and 16 hz) ; 121.5 (273 hz) ; 123.9 (9 hz) ; 131.0, 132.3, 134.0 (13 hz) ; 136.1, 137.7 (36 hz) ; 138.3 (3 hz) ; 151.5, 155.5 (4 and 250 hz), 155.6. obtained in 45% yield as an oil, using 2-bromo-5-cyclopropylpyrazine in acetonitrile at 160 c for 2 h and a chromatography over silica gel (cyclohexane / dichloromethane from 3/2 to 1/2). h nmr (cdcl3) : 1.04 (m, 4h), 1.25 (d, 6h, j = 6.2), 2.07 (m, 1h), 2.61 (s, 3h), 4.88 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.02 (m, 1h), 8.17 (d, 1h, j = 1.4), 8.90 (d, 1h, j = 1.4). c nmr (cdcl3) : 9.6, 11.4, 14.1, 28.1, 72.1, 111.9 (6 and 17 hz) ; 123.5 (9 hz) ; 129.5, 131.2, 134.5 (14 hz) ; 136.4, 138.7, 147.8, 153.2, 154.1, 155.6 (4 and 250 hz). obtained in 29% yield as a solid, using 3-chloro-6-methylpyridazine in acetonitrile at 140 c for 2 h and two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate 3/1), the second one over alumina containing 1.5% of water (cyclohexane / dichloromethane from 1/1 to 1/2). h nmr (cdcl3) : 1.25 (d, 6h, j = 6.2), 2.69 (s, 3h), 2.75 (s, 3h), 4.88 (sept, 1h, j = 6.2), 6.89 (m, 2h), 7.00 (m, 1h), 7.35 (d, 1h, j = 9.1), 7.90 (d, 1h, j = 9.1). c nmr (cdcl3) : 12.1, 21.6, 21.8, 72.1, 112.0 (6 and 17 hz) ; 118.9, 123.6 (9 hz) ; 128.8, 129.9, 131.9, 134.4 (13 hz) ; 154.5, 155.6 (4 and 250 hz) ; 155.8, 156.7. obtained in 58% yield as a solid, using 3,6-dichloropyridazine in acetonitrile at 140 c for 1 h and a chromatography over silica gel (cyclohexane / ethyl acetate from 97/3 to 95/5). h nmr (cdcl3) : 1.25 (d, 6h, j = 6.2), 2.75 (s, 3h), 4.88 (sept, 1h, j = 6.2), 6.89 (m, 2h), 7.01 (m, 1h), 7.50 (d, 1h, j = 9.3), 8.01 (d, 1h, j = 9.3). c nmr (cdcl3) : 12.3, 21.8, 72.3, 112.0 (6 and 17 hz) ; 121.2, 123.8 (9 hz) ; 129.8, 130.5, 132.2, 134.2 (14 hz) ; 152.6, 155.1, 155.6 (4 and 250 hz) ; 156.4. hrms calcd for c17h15clf2n4o2 + h : 381.0930. found : 381.0927. in a 20 ml biotage tube, 3-ethoxy-4-iodo-5-methyl-1h - pyrazole (1.53 g, 6.07 mmol), cesium carbonate (2.2 g, 6.98 mmol), and 5-cyclopropyl-2-fluoropyridine (0.87 g, 6.37 mmol) were dispersed in acetonitrile (14 ml, dried over 4 molecular sieves). the resulting suspension was adsorbed over silica gel and purified by a chromatography over silica gel (cyclohexane / dichloromethane from 97.5/2.5 to 96.5/3.5) to yield in this order, compound 12a (0.3 g, 13%) as a solid, unreacted (and volatile) 5-cyclopropyl-2-fluoropyridine (0.3 g, 34%) and compound 12b, which was further purified under a high vacuum as an oil (0.14 g, 9%). washing the column with ethyl acetate led then to the isolation of the reduced and uv / tlc - invisible 3-ethoxy-5-methyl-1h - pyrazole. 5-cyclopropyl-2-(3-ethoxy-4-iodo-5-methyl-1h - pyrazol-1-yl)pyridine (12a) : h nmr (cdcl3) 0.73 (m, 2h), 1.03 (m, 2h), 1.45 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.66 (s, 3h), 4.36 (q, 2h, j = 7.2), 7.39 (dd, 1h, j = 2.4 and 8.5), 7.62 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.8, 12.6, 14.7, 15.2, 52.8, 65.0, 114.7, 135.1, 136.3, 143.0, 145.5, 151.3, 162.4. 5-cyclopropyl-2-(3-ethoxy-5-methyl-1h - pyrazol-1-yl)pyridine (12b) : h nmr (cdcl3) 0.71 (m, 2h), 1.02 (m, 2h), 1.42 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.62 (s, 3h), 4.26 (q, 2h, j = 7.2), 5.66 (s, 1h), 7.38 (dd, 1h, j = 2.4 and 8.5), 7.66 (d, 1h, j = 8.5), 8.19 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.6, 12.5, 14.8 (two signals) ; 64.4, 94.9, 114.8, 135.0, 135.6, 142.2, 140.4, 151.6, 162.3. from 3-ethoxy-4-bromo-5-methyl-1h - pyrazole (preparation provided below), using the protocol described for the preparation of compound 12a, compound 12c was obtained in a 48% yield as an oil. h nmr (cdcl3) : 0.72 (m, 2h), 1.04 (m, 2h), 1.46 (t, 3h, j = 7.2), 1.93 (m, 1h), 2.63 (s, 3h), 4.38 (q, 2h, j = 7.2), 7.40 (dd, 1h, j = 2.3 and 8.5), 7.62 (d, 1h, j = 8.5), 8.21 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 12.6, 13.5, 14.7, 65.0, 84.4, 114.6, 135.2, 136.2, 140.0, 145.5, 151.4, 159.7. 3-ethoxy-4-bromo-5-methyl-1h - pyrazole : 3-ethoxy-5-methyl-1h - pyrazole (6.64 g, 52.63 mmol) was dissolved in dry acetonitrile (200 ml), n - bromosuccinimide (9.83 g, 55.26 mmol) was added, and the solution was stirred at room temperature overnight. the acetonitrile was then removed under vacuum, this was dissolved in water and ethyl acetate, and the organic layer was washed six times with water once with brine and dried over magnesium sulfate. removal of the solvent under vacuum allowed the isolation of pure 4-bromopyrazole as a white powder (9.83 g, 91%). h nmr (cdcl3) : 1.42 (t, 3h, j = 7.0), 2.21 (s, 3h), 4.28 (q, 2h, j = 7.0), 9.40 (s(l), 1h). c nmr (cdcl3) : 10.6, 14.8, 65.1, 79.7, 139.2, 160.2. in a 10 ml biotage tube, compound 4 (0.14 g, 0.633 mmol), 5-methoxy-2-bromopyrimidine (0.12 g, 0.665 mmol), cesium carbonate (0.22 g, 0.696 mmol), 4 molecular sieves (0.1 g, 3.2 mm pellets), and [n, n-bis((2-pyridine)-methylene)]-1,2-diaminocyclohexane (0.018 g, 0.063 mmol) were dispersed in acetonitrile (4.5 ml, dried over 4 molecular sieves). copper oxide (0.004 g, 0.031 mmol) was then added, and the tube was sealed. this was shaken thoroughly, heated for 30 s in the microwave oven at 100 c, and shaken again. at this stage, the pink copper oxide is well dissolved in the reaction mixture, if not, another 30 s heating at 100 c is required. the heating was then resumed at 180 c for 6 h. the resulting suspension was directly adsorbed over a small amount of silica gel, and this was subjected to a chromatography over silica gel (cyclohexane / ethyl acetate 9/1) to give the 5-methoxypyridine derivative (0.11 g, 53%) as a white solid. h nmr (cdcl3) : 1.42 (t, 3h, j = 7.2), 2.51 (s, 3h), 3.76 (s, 2h), 3.88 (s, 3h), 4.36 (q, 2h, j = 7.2), 7.19 (m, 1h), 7.30 (m, 5h), 7.67 (d, 1h, j = 8.5), 8.09 (d, 1h, j = 2.3). c nmr (cdcl3) : 12.6, 14.9, 27.8, 55.9, 64.4, 105.9, 116.4, 123.9, 125.7, 128.2 (two signals) ; 133.4, 138.8, 141.1, 147.6, 153.2, 162.0. hrms calcd for c19h21n3o2 + h : 324.1712. found : 324.1678. by using the same procedure described above for the preparation of 2-(4-benzyl-3-ethoxy-5-methyl-1h - pyrazol-1-yl)-5-methoxypyridine (6p), this compound was obtained as a solid in 64% yield after a chromatography over silica gel (cyclohexane / ethyl acetate from 97/3 to 95/5). h nmr (cdcl3) : 1.25 (d, 6h, j = 6.2), 2.60 (s, 3h), 3.87 (s, 3h), 4.88 (sept, 1h, j = 6.2), 6.90 (m, 2h), 6.98 (m, 1h), 7.30 (dd, 1h, j = 2.4 and 8.5), 7.65 (d, 1h, j = 8.5), 8.06 (d, 1h, j = 2.4). c nmr (cdcl3) : 11.3, 21.9, 55.9, 71.9, 112.0 (6 and 17 hz) ; 115.7, 123.4 (9 hz) ; 124.0, 128.8, 133.2, 134.8 (13 hz) ; 147.7, 153.3, 155.7 (4 and 250 hz). compound 6 t (0.17 g, 0.48 mmol) was dissolved in dichloromethane (10 ml) and trifluoroacetic acid (2 ml). triethylsilane (0.28 ml, 1.75 mmol) was added, and the reaction was stirred at room temperature for 4 h. an lc / ms pointed out a very slow reaction. trifluoromethanesulfonic acid (0.2 ml, 2.26 mmol) was added, followed by some more triethylsilane (0.2 ml, 1.25 mmol). a hydrogen evolution was observed, and lc / ms monitoring pointed out the occurrence of compound 6u. more triethylsilane (0.2 ml, 1.25 mmol) was added, and this was stirred 24 h. the resulting solution was diluted in ethyl acetate, washed until neutrality with saturated sodium hydrogenocarbonate and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate from 97/3), the second one over silica gel (toluene), to yield compound 6u (0.04 g, 24%) as an oil. h nmr (cdcl3) : 1.30 (t, 6h, j = 6.8), 1.41 (t, 3h, j = 7.1), 2.55 (s, 3h), 2.96 (sept, 1h, j = 6.8), 3.75 (s, 2h), 4.35 (q, 2h, j = 7.1), 7.18 (m, 1h), 7.28 (m, 4h), 7.61 (dd, 1h, j = 2.4 and 8.6), 7.67 (d, 1h, j = 8.6), 8.25 (d, 1h, j = 2.4). c nmr (cdcl3) : 11.9, 13.9, 22.7, 26.7, 30.2, 63.1, 105.2, 114.1, 124.7, 127.2 (two signals) ; 135.0, 138.1, 138.8, 140.0, 144.5, 151.1, 161.1. hrms calcd for c21h25n3o + h : 336.2076. found : 336.2051. in a tube adapted for microwave oven, 2-(4-benzyl-3-ethoxy-5-methyl-1h - pyrazol-1-yl)-5-bromopyridine (0.16 g, 0.43 mmol), cesium carbonate (0.7 g, 2.14 mmol), and cyclopropyl boronic acid (0.11 g, 1.28 mmol) in dimethylformamide (4 ml, dried over 4 molecular sieves) were mixed. this suspension was degassed by a gentle stream of argon, [1,1-bis(diphenylphosphino)ferrocene ] dichloropalladium complexed with dichloromethane (0.017 g, 0.021 mmol) was added, the tube was sealed, and heated in a microwave oven at 110 c for 1 h. the resulting suspension was diluted in water and extracted with ethyl acetate. the organic layer was washed with brine, dried over sodium sulfate, and concentrated to dryness. the residue was purified first by a chromatography over silica gel (cyclohexane / ethyl acetate from 2/1 to 3/2) to yield the 5-cyclopropyl derivative as a white powder (0.07 g, 48%). h nmr (cdcl3) : 0.78 (m, 2h), 1.03 (m, 2h), 1.41 (t, 3h, j = 7.0), 1.91 (m, 1h), 2.54 (s, 3h), 3.76 (s, 2h), 4.35 (q, 2h, j = 7.0), 7.18 (m, 1h), 7.28 (m, 4h), 7.38 (m, 1h), 7.65 (m, 1h), 8.20 (m, 1h). c nmr (cdcl3) : 8.7, 12.5, 12.9, 14.9, 27.8, 64.2, 106.3, 115.0, 125.7, 128.2, 128.3, 135.1, 135.3, 139.1, 141.0, 145.4, 151.8, 162.2. hrms calcd for c21h23n3o + h : 334.1919. found : 334.1931. under an atmosphere of argon, compound 12a (0.31 g, 0.83 mmol) was dissolved in dry thf (10 ml). this was cooled to 78 c, and 2 m butyl lithium in cyclohexane (0.63 ml, 1.25 mmol) was added. this was stirred at 78 c for 5 min before adding benzoyl chloride (0.14 ml, 1.25 mmol). the resulting solution was allowed to warm to room temperature, water was added, and this was extracted with ethyl acetate. the organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a chromatography over silica gel (cyclohexane / ethyl acetate from 97/3 to 95/5) to yield the benzoyl derivative 13 as a glass (0.13 g, 44%). h nmr (cdcl3) : 0.78 (m, 2h), 1.09 (m, 2h), 1.23 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.75 (s, 3h), 4.28 (q, 2h, j = 7.2), 7.47 (m, 4h), 7.53 (m, 1h), 7.64 (d, 1h, j = 8.5), 7.84 (dd, 1h, j = 8.5 and 2.3), 8.29 (d, 1h, j = 2.3). c nmr (cdcl3) : 9.1, 12.7, 13.8, 14.4, 64.6, 108.8, 116.9, 127.7, 129.4, 132.0, 135.1, 137.7, 139.4, 145.9, 146.2, 150.5, 161.3, 190.7. compound 13 (0.07 g, 0.2 mmol) and sodium borohydride (0.074 g, 2.01 mmol) were stirred overnight in methanol (15 ml) at room temperature. this was neutralized with acetic acid, concentrated to dryness, and diluted in ethyl acetate. the organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a chromatography over silica gel (dichloromethane ethanol from 99.5/0.5 to 98/2) to yield the alcohol as a glass (0.05 g, 71%). h nmr (cdcl3) : 0.72 (m, 2h), 1.03 (m, 2h), 1.38 (t, 3h, j = 7.2), 1.92 (m, 1h), 2.51 (s, 3h), 4.35 (q, 2h, j = 7.2), 5.82 (s, 1h), 7.25 (m, 1h), 7.37 (m, 3h), 7.47 (m, 2h), 7.60 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 12.6, 12.9, 14.8, 64.5, 67.8, 109.2, 115.6, 126.0, 127.0, 128.2, 129.8, 135.1, 138.9, 143.6, 145.6, 151.4, 160.9. hrms calcd for c21h23n3o2 + h : 350.1869. found : 350.1829. under an argon atmosphere, compound 13 (0.05 g, 0.14 mmol) was dissolved in dry tetrahydrofuran (5 ml) at room temperature. a 1.6 m solution of methyllithium in ether (0.5 ml, 0.84 mmol) was added and the solution stirred for 5 min. this was diluted in water, extracted with ethyl acetate, the organic layer was washed with water and brine, dried over magnesium sulfate, and concentrated to dryness. the residue was further purified by a chromatography over silica gel (dichloromethane / ethanol from 98/2) to yield the tertiary alcohol as a glass (0.04 g, 76%). h nmr (cdcl3) : 0.72 (m, 2h), 1.04 (m, 2h), 1.38 (t, 3h, j = 7.2), 1.91 (m, 1h), 1.95 (s, 3h), 2.31 (s, 3h), 3.52 (s, 1h), 4.32 (m, 2h), 7.257.55 (m, 7h), 8.21 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.8, 12.6, 13.3, 14.8, 31.2, 64.6, 73.3, 112.6, 116.9, 125.5, 126.7, 126.9, 127.9, 135.0, 136.6, 138.5, 145.7, 151.2, 161.6. hrms calcd for c22h25n3o2 + h : 364.2025. found : 364.1948. in a vial adapted for microwave heating, compound 12c (0.21 g, 0.65 mmol), phenylboronic acid (0.087 g, 0.71 mmol), and cesium carbonate (0.53 g, 1.69 mmol) were dissolved in a 2/3 mixture of propanol and water (5 ml). this was degassed by a gentle steam of argon, [1,1-bis(diphenylphosphino)ferrocene ] dichloropalladium complexed with dichloromethane (0.026 g, 0.032 mmol) was added, and the sealed tube heated at 120 c for 30 min. the organic layer was washed with brine, dried over sodium sulfate, and concentrated to dryness. the residue was purified first by a chromatography over alumina containing 1.5% water (cyclohexane / dichloromethane from 1/0 to 1/1) to yield the 4-phenyl derivative as a solid (0.07 g, 33%). h nmr (cdcl3) : 0.74 (m, 2h), 1.05 (m, 2h), 1.44 (t, 3h, j = 7.2), 1.93 (m, 1h), 2.68 (s, 3h), 4.40 (q, 2h, j = 7.2), 7.27 (m, 1h), 7.43 (m, 3h), 7.51 (m, 2h), 7.68 (d, 1h, j = 8.4), 8.24 (d, 1h, j = 2.3). c nmr (cdcl3) : 8.7, 12.6, 13.7, 14.9, 64.4, 109.3, 115.6, 126.2, 128.3, 129.2, 131.9, 135.1, 135.9, 138.9, 145.6, 151.6, 160.9. preparation of benzylzinc bromide : a 100 ml round - bottom flask was charged with lithium chloride (3.9 g, 92.6 mmol). this was thoroughly dried with an open flame for two min under vacuum and then allowed to cool under an argon atmosphere. still under an inert atmosphere, zinc dust (5.5 g, 84.2 mmol ; vwr technical 6% oxide) was added. anhydrous tetrahydrofuran (50 ml) was injected, and the flask cooled using an ice bath. benzyl bromide (5 ml, 42.1 mmol.) was added via the septum ; the mixture was sonicated for 45 s and allowed to stir at 4 c overnight (17 h). this solution was stocked for 3 month at 4 c, leading to a 0.68 molar (80%) transparent solution of benzylzinc bromide as measured by the titration method previously reported. second step : compound 12c (0.23 g, 0.71 mmol), palladium acetate (0.008 g, 0.036 mmol), and 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl (xphos) (0.084 g, 0.071 mmol) were added in a flask flushed with argon. anhydrous tetrahydrofuran (5 ml) was injected, and the resulting solution was allowed to stir a few minutes. a fraction of the solution of benzylzinc bromide described above (3.2 ml, 2.14 mmol) was injected, and the mixture heated for 16 h at 50 c. the aqueous layer was extracted once with ethyl acetate, the organic layer was washed with brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a chromatography over silica gel (dichloromethane / ethanol 99.5:0.5) followed by drying under high vacuum to yield compound 6q as a yellowish oil (0.17 g, 71%) with analytical data identical with the one described above. preparation of (1-phenylethyl)zinc chloride : a 20 ml tube adapted for microwave heating was charged with lithium chloride (0.48 g, 11.3 mmol). this was thoroughly dried with an open flame for two min and then allowed to cool under an argon atmosphere. still under an inert atmosphere, zinc dust (0.74 g, 11.3 mmol ; size < 10 m) was added and the tube was sealed. anhydrous tetrahydrofuran (10 ml) was injected, followed by 0.2 m dibromoethane solution in tetrahydrofuran (1.9 ml, 0.38 mmol). this was allowed to cool, a 0.06 m trimethylsilychloride solution in tetrahydrofuran (1.25 ml, 0.075 mmol) was added, and the tube was heated again with microwave irradiation for 5 min at 85 c. after cooling, (1-chloroethyl)benzene (1 ml, 7.5 mmol) was added via the septum, and the mixture was heated using microwave irradiation for 1 h at 80 c. this led to a 0.47 molar (88%) yellow solution of (1-phenylethyl)zinc chloride as measured by the titration method previously reported. second step : compound 12c (0.31 g, 0.96 mmol), palladium acetate (0.011 g, 0.048 mmol), and 2-dicyclohexylphosphino-2,6-bis(n, n - dimethylamino)biphenyl (cphos) (0.042 g, 0.096 mmol) were added in a flask flushed with argon. the decanted solution of (1-phenylethyl)zinc chloride described above (6.1 ml, 2.89 mmol) was injected, and the mixture heated for 16 h at 50 c. the resulting suspension the aqueous layer was extracted once with ethyl acetate, and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated to dryness. the residue was purified by a chromatography over silica gel (dichloromethane), followed by drying under high vacuum to yield compound 16 as a colorless oil (0.14 g, 42%). h nmr (cdcl3) : 0.72 (m, 2h), 1.04 (m, 2h), 1.42 (t, 3h, j = 7.1), 1.71 (d, 3h, j = 7.4), 1.92 (m, 1h), 2.51 (s, 3h), 4.08 (q, 1h, j = 7.3), 4.30 (m, 2h), 7.20 (m, 1h), 7.30 (m, 2h), 7.40 (m, 3h), 7.61 (d, 1h, j = 8.5), 8.20 (d, 1h, j = 2.4). c nmr (cdcl3) : 8.6, 12.6, 12.8, 14.9, 20.0, 34.2, 64.1, 111.0, 115.4, 125.7, 127.3, 128.1, 135.0, 135.4, 138.0, 145.5, 146.1, 151.8, 161.9. compound 18d (0.17 g, 0.42 mmol) and 10% palladium over charcoal (0.066 g, 0.062 mmol) were dispersed in ethanol (20 ml). this was charged with hydrogen at 1 atm and stirred at room temperature for 5 days. the suspension was filtered, the filtrate concentrated to dryness, and the residue purified by a chromatography over silica gel (cyclohexane / ethyl acetate 97/3) followed by drying under high vacuum to give compound 18o as an oil (0.05 g, 30%). h nmr (cdcl3) : 1.00 (t, 3h, j = 7.3), 1.23 (d, 6h, j = 6.2), 1.69 (m, 2h), 2.28 (s, 3h), 2.66 (t, 2h, j = 7.4), 4.88 (sept, 1h, j = 6.2), 6.89 (m, 2h), 7.01 (m, 1h), 7.39 (m, 1h), 8.18 (m, 1h). c nmr (cdcl3) : 9.3, 13.5, 21.9, 24.0, 34.2, 71.9, 111.9 (6 and 17 hz) ; 123.5 (9 hz) ; 125.2 (17 hz) ; 128.3, 131.1, 134.7 (14 hz) ; 138.5 (11 hz) ; 139.5 (3 hz) ; 144.0 (5 hz) ; 152.7 (260 hz) ; 154.1, 155.7 (4 and 250 hz). hrms calcd for c21h22f3n3o2 + h : 406.1742. found : 406.1713. compound 18d (0.11 g, 0.272 mmol) and cesium carbonate (0.13 g, 0.409 mmol) dissolved in methanol (2 ml) were heated in a microwave oven at 150 c for 90 min. this was concentrated to dryness and the residue purified by a chromatography over silica gel (cyclohexane / ethyl acetate 4/1) to yield the methoxy ether 18p (0.08 g, 70%) as an oil. h nmr (cdcl3) : 0.77 (m, 2h), 1.08 (m, 2h), 1.21 (d, 6h, j = 6.2), 1.96 (m, 1h), 2.11 (s, 3h), 3.79 (s, 3h), 4.87 (sept, 1h, j = 6.2), 6.87 (m, 2h), 7.00 (m, 2h), 7.97 (d, 1h, j = 2.0). c nmr (cdcl3) : 9.0, 9.3, 13.0, 22.0, 56.0, 71.7, 111.9 (6 and 16 hz) ; 118.2, 123.4 (9 hz) ; 127.4, 131.2, 134.9 (14 hz) ; 138.7, 139.2, 141.4, 150.7, 153.5, 155.8 (4 and 249 hz). compound 18d (0.06 g, 0.148 mmol), cesium, and a 2n solution of dimethylamine in tetrahydrofuran (0.5 ml) in tetrahydrofuran (2 ml) were heated in a microwave oven at 180 c for 9 h. this was concentrated to dryness and the residue purified by a chromatography over silica gel (cyclohexane / ethyl acetate 9/1) to yield the n - dimethylamine 18q (0.04 g, 62%) as an oil. h nmr (cdcl3) : 0.75 (m, 2h), 1.03 (m, 2h), 1.20 (d, 6h, j = 6.2), 1.91 (m, 1h), 2.09 (s, 3h), 2.56 (s, 6h), 4.89 (sept, 1h, j = 6.2), 6.91 (m, 3h), 5.98 (m, 1h), 7.86 (d, 1h, j = 2). c nmr (cdcl3) : (one signal missing) 8.8, 9.0, 13.0, 21.9, 41.3, 71.8, 111.9 (6 and 16 hz) ; 122.8, 123.3 (9 hz) ; 127.5, 130.9, 135.0 (13 hz) ; 139.7, 140.4, 144.3, 153.4, 155.7 (4 and 249 hz). hrms calcd for c23h26f2n4o3 + h : 429.2102. found : 429.2023. compound 18d (0.38 g, 0.94 mmol) and cesium carbonate (0.34 g, 1.03 mmol) dissolved in benzylalcohol (2 ml) were heated in a microwave oven at 150 c for 90 min. this was concentrated to dryness and the residue purified by two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate 4/1) and the second one over alumina containing 1.5% of water (cyclohexane / dichloromethane 1/1) to yield the benzyl ether 18r (0.14 g, 29%) as an oil. h nmr (cdcl3) : 0.74 (m, 2h), 1.08 (m, 2h), 1.22 (d, 6h, j = 6.1), 1.92 (m, 1h), 2.13 (s, 3h), 4.89 (sept, 1h, j = 6.1), 5.02 (s, 2h), 6.97 (m, 2h), 7.02 (m, 2h), 7.31 (m, 5h), 8.01 (d, 1h, j = 2.0). c nmr (cdcl3) : 9.1, 9.4, 12.9, 22.0, 71.1, 71.8, 111.9 (6 and 17 hz) ; 123.4 (9 hz) ; 127.1, 127.5, 128.0, 128.5, 131.2, 134.9 (14 hz) ; 135.9, 139.3, 139.9, 141.4, 149.8, 153.6, 155.8 (4 and 249 hz). hrms calcd for c29h27f2n3o3 + h : 492.2099. found : 492.2076. compound 18r (0.22 g, 0.44 mmol), ammonium formate (0.11 g, 1.79 mmol), and 10% palladium over charcoal (0.023 g, 0.021 mmol) were heated to reflux in ethanol (50 ml) for 45 min. this was adsorbed over silica gel and purified by a chromatography over silica gel (cyclohexane / ethyl acetate 95/5) to yield the hydroxyl derivative 18s (0.13 g, 72%) as an oil. h hmr (cdcl3) : 0.71 (m, 2h), 1.01 (m, 2h), 1.25 (d, 6h, j = 6.1), 1.89 (m, 1h), 2.69 (s, 3h), 4.75 (sept, 1h, j = 6.1), 6.92 (m, 3h), 7.04 (m, 1h), 7.75 (d, 1h, j = 2.0), 10.98 (s, 1h). c nmr (cdcl3) : 8.9, 11.8, 12.4, 21.9, 72.9, 112.0 (6 and 17 hz) ; 121.9, 123.7 (9 hz) ; 128.0, 132.6, 134.5 (14 hz) ; 135.8, 137.5, 138.1, 144.9, 151.2, 155.6 (5 and 250 hz). hrms calcd for c21h21f2n3o3 + h : 402.1629. found : 402.1642. by using the procedure described above for the preparation of compound 6p, this compound was obtained from 5-bromo-2-methylpyridine as a solid in 34% yield after two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate 3/1), the second one over alumina containing 1.5% of water (cyclohexane / dichloromethane from 2/3 to 1/1). h nmr (cdcl3) : 1.23 (d, 6h, j = 6.2), 2.32 (s, 3h), 2.59 (s, 3h), 4.83 (sept, 1h, j = 6.2), 6.92 (m, 2h), 7.02 (m, 1h), 7.22 (d, 1h, j = 8.4), 7.66 (dd, 1h, j = 2.5 and 8.4), 8.58 (d, 1h, j = 2.5). c nmr (cdcl3) : 10.0, 21.9, 23.9, 72.1, 112.0 (6 and 17 hz) ; 123.2, 123.6 (9 hz) ; 128.4, 129.6, 131.5, 134.4, 134.6 (14 hz) ; 144.0, 153.8, 155.7 (4 and 250 hz) ; 156.4. hrms calcd for c19h19f2n3o2 + h : 360.1524. found : 360.1515. by using the procedure described above for the preparation of compound 6p, this compound was obtained from 5-bromo-2-ethylpyridine as an oil in 42% yield after two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate 5/1), the second one over alumina containing 1.5% of water (cyclohexane / dichloromethane 3/2). h nmr (cdcl3) : 1.23 (d, 6h, j = 6.2), 1.33 (t, 3h, j = 7.6), 2.33 (s, 3h), 2.87 (q, 2h, j = 7.6), 4.83 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.02 (m, 1h), 7.23 (d, 1h, j = 8.5), 7.68 (dd, 1h, j = 2.4 and 8.5), 8.58 (d, 1h, j = 2.4). c nmr (cdcl3) : 10.0, 13.8, 21.9, 30.9, 72.1, 112.0 (6 and 17 hz) ; 122.0, 123.6 (10 hz) ; 128.4, 129.6, 131.6, 134.5, 134.6 (14 hz) ; 144.1, 153.8, 155.7 (4 and 250 hz) ; 161.5. hrms calcd for c20h21f2n3o2 + h : 374.1680. found : 374.1667. by using the procedure described above for the preparation of compound 6p, this compound was obtained from 5-bromo-2-methoxypyridine as a solid in 16% yield after a chromatography over silica gel (cyclohexane / ethyl acetate 9/1). h nmr (cdcl3) : 1.23 (d, 6h, j = 6.2), 2.27 (s, 3h), 3.97 (s, 3h), 4.81 (sept, 1h, j = 6.2), 6.82 (d, 1h, j = 8.7), 6.91 (m, 2h), 7.02 (m, 1h), 7.65 (dd, 1h, j = 2.7 and 8.7), 8.20 (d, 1h, j = 2.7). c nmr (cdcl3) : 9.7, 21.9, 53.8, 72.0, 111.9, 112.9 (6 and 17 hz) ; 123.6 (9 hz) ; 127.9, 129.8, 130.9, 134.7 (14 hz) ; 135.4, 142.3, 153.5, 155.8 (4 and 250 hz) ; 162.6. hrms calcd for c19h19f2n3o3 + h : 376.1473. found : 376.1446. by using the procedure described above for the preparation of compound 6p, this compound was obtained from 5-bromo-2-tert - butylpyrimidine as a solid in 24% yield after two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate 95/5), the second one over alumina containing 1.5% of water (cyclohexane / dichloromethane 4/1). h nmr (cdcl3) : 1.24 (d, 6h, j = 6.2), 1.46 (s, 9h), 2.36 (s, 3h), 4.82 (sept, 1h, j = 6.2), 6.92 (m, 2h), 7.03 (m, 1h), 8.82 (s, 2h). c nmr (cdcl3) : 10.0, 21.9, 29.6, 39.3, 72.2, 112.0 (6 and 16 hz) ; 123.8, (10 hz) ; 128.9, 129.6, 132.5, 134.4 (14 hz) ; 150.4, 155.6 (4 and 250 hz) ; 174.6. hrms calcd for c21h24f2n4o2 + h : 403.1946. found : 403.1900. in an open flask, compound 7q (0.37 g, 1.38 mmol), a very aged sample of commercially available 2-cyclopropylpyrimidin-5-ylboronic acid (0.25 g, 1.51 mmol), pyridine (0.23 ml, 2.75 mmol, dried over 4 molecular sieves), 4 molecular sieves (0.5 g), and copper(ii) acetate hydrate (0.41 g, 2.06 mmol) were dispersed in dichloromethane (50 ml). the reaction was stirred in open air for 48 h. the suspension was absorbed on a small amount of silica gel and purified by two consecutive chromatography processes, the first one over silica gel (cyclohexane / ethyl acetate 4/1), the second one over alumina containing 1.5% of water (cyclohexane / dichloromethane 1/1) to give the n - arylated compound 20b (0.01 g, 1.8%) as an oil. h nmr (cdcl3) : 1.11 (m, 2h), 1.15 (m, 2h), 1.24 (d, 6h, j = 6.1), 2.30 (m, 1h), 2.35 (s, 3h), 4.82 (sept, 1h, j = 6.1), 6.93 (m, 2h), 7.05 (m, 1h), 8.68 (s, 2h). c nmr (cdcl3) : 9.9, 11.0, 17.9, 21.9, 72.2, 112.0 (6 and 16 hz) ; 123.8, (9 hz) ; 128.8, 129.6, 132.5, 134.4 (14 hz) ; 151.1, 155.4, 155.7 (4 and 250 hz). compound 21a (0.076 g, 0.17 mmol) and cesium carbonate (0.087 g, 0.26 mmol) dissolved in methanol (4 ml) were heated in a microwave oven at 140 c for 60 min. this was concentrated to dryness and the residue purified by a chromatography over silica gel (cyclohexane / dichloromethane from 3/2 to 2/1) to yield the methoxy ether 21c (0.04 g, 59%) as a white powder. h nmr (cdcl3) : 1.25 (d, 6h, j = 6.2), 2.55 (s, 3h), 3.99 (s, 3h), 4.88 (sept, 1h, j = 6.2), 6.89 (m, 2h), 7.00 (m, 1h), 7.98 (d, 1h, j = 1.3), 8.54 (d, 1h, j = 1.3). c nmr (cdcl3) : 11.0, 21.9, 53.9, 72.1, 112.0 (6 and 17 hz) ; 123.5 (9 hz) ; 129.0, 130.8, 130.9, 133.1, 134.5 (14 hz) ; 144.4, 153.8, 155.6 (4 and 249 hz) ; 157.8. hrms calcd for c18h18f2n4o3 + h : 377.1425. found : 377.1372. by using the procedure described for the preparation of compound 21a, compound 22c was obtained from compound 22b as a white powder in 80% after a chromatography over silica gel (cyclohexane / dichloromethane from 9/1). h nmr (cdcl3) : 1.24 (d, 6h, j = 6.2), 2.72 (s, 3h), 4.14 (s, 3h), 4.86 (sept, 1h, j = 6.2), 6.91 (m, 2h), 7.03 (m, 2h), 7.96 (d, 1h, j = 9.4). c nmr (cdcl3) : 12.0, 21.9, 54.9, 72.1, 111.9 (6 and 17 hz) ; 119.8, 123.2, 123.6 (9 hz) ; 129.6, 131.5, 134.5 (14 hz) ; 153.8, 154.2, 155.6 (4 and 249 hz) ; 163.0. hrms calcd for c18h18f2n4o3 + h : 377.1425. found : 377.1364. by using the procedure described for the preparation of compound 21a, compound 22d was obtained from 22b and ethanol as a solid in 71% after a chromatography over silica gel (cyclohexane / dichloromethane from 9/1). h nmr (cdcl3) : 1.24 (d, 6h, j = 6.2), 1.47 (d, 6h, j = 7.1), 2.72 (s, 3h), 4.58 (q, 2h, j = 7.1), 4.86 (sept, 1h, j = 6.2), 6.92 (m, 2h), 7.03 (m, 2h), 7.96 (d, 1h, j = 9.5). c nmr (cdcl3) : 11.9, 14.5, 21.9, 63.4, 72.1, 120.0 (6 and 17 hz) ; 119.8, 123.2, 123.5 (9 hz) ; 129.6, 131.5, 134.5 (14 hz) ; 153.6, 154.1, 155.6 (4 and 249 hz) ; 162.8. 6-ethyl-3-(methylthio)-1,2,4-triazin-5-ol (0.17 g, 1.01 mmol) and 4-(2,6-difluorophenoxy)-3-isopropoxy-5-methyl-1h - pyrazole (0.272 g, 1.01 mmol) were heated in a sealed tube at 200 c four 12 h. the resulting tarry solid was dispersed in ethanol, adsorbed over silica, and purified by two consecutive chromatography processes over silica gel (dichloromethane / ethanol 98/2) and (cyclohexane / ethyl acetate from 2/1 to 1/1) to give the n - arylated derivative as a glass (0.04 g, 10%). h nmr (cdcl3) : 1.23 (t, 3h, j = 7.5), 1.25 (d, 6h, j = 6.2), 2.71 (s, 3h), 2.76 (q, 2h, j = 7.5), 4.86 (sept, 1h, j = 6.2), 6.90 (m, 2h), 7.04 (m, 1h), 10.89 (s(l), 1h). c nmr (cdcl3) : 10.0, 12.1, 21.6, 24.0, 73.2, 111.9 (6 and 17 hz) ; 124.2 (9 hz) ; 131.4, 133.7 (14 hz) ; 133.8, 150.4, 154.4, 155.4 (4 and 250 hz) ; 156.1, 162.7. hrms calcd for c18h19f2n5o3 + h : 392.1534. found : 392.1538. in a 10 ml biotage tube, compound 7q (0.2 g, 0.74 mmol), 1-ethyl-4-iodo-1h - imidazole (0.17 g, 0.78 mmol), cesium carbonate (0.27 g, 0.83 mmol), 4 molecular sieves (0.1 g, 3.2 mm pellets) and [n, n-bis((2-pyridine)-methylene)]-1,2-diaminocyclohexane were dispersed in acetonitrile (4.5 ml, dried over 4 molecular sieves). this was degassed using a slow stream of argon bubbling in the suspension. copper oxide (0.005 g, 0.034 mmol) was then added, and the tube was sealed. this was shaken thoroughly, heated for 30 s in the microwave oven at 100 c, and shaken again. at this stage the pink copper oxide is well dissolved in the reaction mixture ; if not, another 30 s heating at 100 c is required. the resulting suspension was directly adsorbed over a small amount of silica gel, and this was subjected to a chromatography over silica gel (dichloromethane / ethanol 99/1 98/2) to give compound 24 as an oil (0.13 g, 48%). h nmr (cdcl3) : 1.22 (d, 6h, j = 5.2), 1.51 (t, 3h, j = 7.3), 2.39 (s, 3h), 4.00 (q, 2h, j = 7.3), 4.85 (m, 1h), 6.90 (m, 2h), 6.98 (m, 1h), 7.06 (s(br)), 7.44 (s(br), 1h). c nmr (cdcl3) : 9.8, 16.0, 22.0, 42.6 (br) ; 71.8, 111.9 (6 and 17 hz) ; 123.4 (9 hz) ; 130.5 (br) ; 134.8 (14 hz) ; 140.2 (br) ; 153.7 (4 and 250 hz). | following our discovery of human dihydroorotate dehydrogenase (dhodh) inhibition by 2-(3-alkoxy-1h - pyrazol-1-yl)pyrimidine derivatives as well as 2-(4-benzyl-3-ethoxy-5-methyl-1h - pyrazol-1-yl)-5-methylpyridine, we describe here the syntheses and evaluation of an array of azine - bearing analogues. as in our previous report, the structure activity study of this series of human dhodh inhibitors was based on a phenotypic assay measuring measles virus replication. among other inhibitors, this round of syntheses and biological evaluation iteration led to the highly active 5-cyclopropyl-2-(4-(2,6-difluorophenoxy)-3-isopropoxy-5-methyl-1h - pyrazol-1-yl)-3-fluoropyridine. inhibition of dhodh by this compound was confirmed in an array of in vitro assays, including enzymatic tests and cell - based assays for viral replication and cellular growth. this molecule was found to be more active than the known inhibitors of dhodh, brequinar and teriflunomide, thus opening perspectives for its use as a tool or for the design of an original series of immunosuppressive agent. moreover, because other series of inhibitors of human dhodh have been found to also affect plasmodium falciparum dhodh, all the compounds were assayed for their effect on p. falciparum growth. however, the modest in vitro inhibition solely observed for two compounds did not correlate with their inhibition of p. falciparum dhodh. |
significant evidence ties gestational weight gain (gwg) to short- and long - term maternal and infant outcomes. to optimize maternal and child health, the institute of medicine (iom) provides guidelines for gwg based on prepregnancy body mass index (bmi). greater gwg is recommended for women with prepregnancy bmis in the underweight (2840 pounds (lbs), 12.718.1 kg) or healthy weight (2535 lbs, 11.315.9 kg) range, with less gwg recommended for prepregnancy overweight (1525 lbs, 6.811.3 kg) and obese (1120 lbs, 5.09.1 kg) women. only 22 to 40% of women attain gwg within the recommended ranges [28 ], and women of lower socioeconomic status and racial / ethnic minority women have lower adherence to gwg guidelines [5, 911 ]. among latina women and depending on national origin, estimates of excessive gwg range from 36 to 51%, whereas estimates of insufficient gwg range from 17 to 30% [7, 9, 10, 12, 13 ]. socioeconomic and racial / ethnic disparities in achieving recommended gwg are further compounded by higher pregnancy rates and greater odds of adverse birth - related outcomes among socioeconomically disadvantaged and racial / ethnic minority populations than their more affluent and white counterparts. the pregnancy rate of latina women in the us is estimated to be two - thirds higher than that of non - latino whites. within the latina population, nearly half of caribbean latina women experience gwg above iom guidelines, and puerto rican latinas are among women with the highest rates of low birth weight neonates and preterm births, both predictors of infant mortality. however, little is known about why adherence to guidelines is low among this population. identifying and understanding factors driving racial / ethnic differences in gwg are a priority to target maternal and child health disparities in this growing and at - risk population. given the numerous adverse health consequences of excessive and insufficient gwg for the mother and the offspring [1, 4, 1821 ], understanding the risk factors for low adherence to iom - recommended gwg and intervening in at - risk groups are of utmost importance. however, little is known about the influence of early gwg (e.g., first trimester) on overall gwg and other maternal and infant outcomes. a prospective study of a predominantly white female sample indicated that maternal weight change in the first trimester was a stronger predictor of birth weight than weight change in the second or third trimester. the timing and extent of gwg may also be an important determinant of birth weight as well as other maternal and prenatal outcomes ; thus, early identification of women who are at risk of excessive or inadequate gwg may be critical to guide the timing and content for intervention delivery to maximize maternal and prenatal health and reduce health disparities. to address gaps in the literature, this study aimed to examine differences in predictors of gestational weight gain (gwg), assess the association of first - trimester gwg to overall gwg between non - latina white and latina women, and examine gwg status with birth outcomes. we hypothesized that women who were overweight or obese before pregnancy would have higher odds of gwg outside of iom recommendations and that first - trimester gwg status (below, within, or above guideline) would positively correlate with overall gwg. the study 's targeted population included non - latina white and latina women who received prenatal care from private providers and hospital clinics (i.e., a resident clinic and a midwifery clinic). the study was conducted at baystate medical center, a large tertiary care facility in western massachusetts with an average of 4,300 deliveries each year, approximately 57% of them to latina women (primarily of puerto rican origin). first, electronic medical record database searches were performed for a retrospective cohort of women who had live deliveries (preterm or full - term) at the medical center from september 1, 2005, to august 31, 2006. women with multifetal pregnancies, unknown ethnicity, and primary language other than english or spanish were excluded. a total of 3,966 (of 4,300) patient records met these criteria. based on estimates of adherence to iom guidelines in other samples, a sample size of at least 400 women thus, the second screening step consisted of randomly selecting one quarter (n = 1,016) of eligible patient records, stratified by ethnicity (non - latina white and latina) and site of prenatal care (hospital clinics and private providers), for additional participant eligibility screening via paper medical chart review. reasons for exclusion included missing data on prepregnancy weight (n = 226) or height (n = 4), missing dates of prenatal measurements (n = 138), no documentation of prenatal visits in the first trimester of pregnancy (n = 296), maternal history of gastric bypass (n = 2), or maternal diagnosis of pregestational diabetes (n = 31). of excluded records, 60% were excluded for one criterion and 40% were excluded for two or more criteria. the form included fields for recording participant demographics (date of birth, race / ethnicity, primary language, marital status, insurance type, parity, and employment status), psychiatric history (i.e., documented psychiatric diagnosis or use of psychiatric medication), height, and dates and measured weights at each prenatal visit. three research assistants were trained in the process of data abstraction from paper medical records until 100% interrater reliability was achieved. data from completed and cross - checked abstraction forms were scanned and were uploaded into a sas database. data abstraction was performed from 2007 to 2008. during this time frame, revisions of iom 's gwg guidelines were anticipated and were available following data cleaning procedures and at the time of analyses. thus, the investigative team decided a priori to utilize 2009 guidelines in categorizing gwg measures (described below) with the goal of providing an estimate of likely nonadherence to new recommendations and associated outcomes. additionally, the 2009 guidelines did not differ greatly from former guidelines yet offered the benefit of a recommended range of gain for obese women in contrast to the previously stated at least 15 pounds (6.8 kg) without an upper bound. all study protocols and procedures were approved by the baystate medical center institutional review board and the university of massachusetts medical school institutional review board. height and prepregnancy weight were obtained from prenatal forms in participants ' medical records. customarily, height is measured by obstetric provider office staff and prepregnancy weight is self - reported by pregnant women at their first prenatal appointment. prepregnancy bmi was calculated as weight (kg)/height squared (in meters) and categorized as follows : underweight (bmi 0.05) ; thus, results are presented for the entire sample. multivariable logistic regression models estimating participant characteristics associated with gwg status at time of delivery (table 3) indicated that odds of above - guideline gwg at time of delivery were greater among prepregnancy overweight and obese women compared to healthy weight women (or = 3.4, ci = 1.86.5 ; or = 4.5, ci = 2.39.0, resp.) and among those with first - trimester gwg above guidelines compared to those with gwg within guidelines (or = 4.9, ci = 2.88.8). odds of below - guideline gwg at time of delivery were greater among prepregnancy underweight and obese women compared to healthy weight (or = 5.3, ci = 1.420.2 ; or = 3.5, ci = 1.48.7, resp.) and among women with first - trimester gwg below guidelines compared to within - guideline gwg (or = 3.0, ci = 1.36.8). odds of below - guideline gwg were lower among women receiving care at hospital clinics compared to those receiving care from a private provider and among past smokers compared to never smokers (or = 0.3, ci = 0.10.9 ; or = 0.3, ci = 0.11.0, resp.). thus, table 4 presents estimates of associations between gwg status and length of pregnancy (preterm versus full - term) and birth weight parameters for the overall sample. gwg status was unrelated to pregnancy length but was associated with birth size (a higher percentage of sga in pregnancies with below - guideline gwg and a higher percentage of lga in pregnancies with above - guideline gwg ; p values < 0.05). observed ethnic differences in birth size (table 1) by which white women were more likely to have lga neonates and latina women were more likely to have sga neonates were not impacted when adjusted for gwg status (data not shown). supplemental analyses from running more parsimonious models and from sensitivity tests did not yield results that were substantially different from those presented (data not shown). findings from this retrospective cohort study provide insights for identifying women at risk for nonadherence to iom - recommended gwg and for developing targeted interventions. above - guideline gwg was greater in this cohort (58%) than in previous studies of multiethnic samples (35%57% in prior studies) [24, 7 ], suggesting that rates of above - guideline gwg may continue to increase, especially among white women. as noted in other populations [2, 7, 30 ], prepregnancy weight status predicted gwg in this study. targeting weight prior to pregnancy is desirable but may be unfeasible for numerous reasons, such as lack of pregnancy intentionality. targeting weight change during pregnancy may be a more feasible window, as a majority of women seek prenatal care during the first - trimester and are motivated to modify health behaviors. to our knowledge, this is the first study to examine first - trimester gwg status as a predictor of gwg status at time of delivery in a multiethnic sample of women, with first - trimester gwg status predicting overall gwg status among non - latina white and latina women. along with other research, study findings indicate that the first trimester of pregnancy may be a critical and feasible window to promote healthy gwg and associated maternal and neonatal outcomes ; thus, the identification of women who are at elevated risk for below or above gwg guidelines (e.g., prepregnancy underweight and overweight / obese women) and subsequent delivery of targeted interventions for these subgroups during early prenatal care should be emphasized. for both non - latina white and latina women in our study sample, maternal smoking status (previous smoker prior to pregnancy) was associated with lower odds of below - recommended gwg which is consistent with previous research indicating that smoking during pregnancy is related to lower gwg and smoking cessation associated with greater gwg [2, 3, 32, 33 ]. between 29% and 70% of women reportedly quit smoking upon becoming pregnant ; thus, health care provider attention to smoking history and smoking patterns during pregnancy, with particular focus given to previous or current smokers during early prenatal care, is important to optimize gwg throughout pregnancy. a larger proportion of sga infants were born to latina women than non - latina white women, with the prevalence of sga (12.2%) and preterm delivery (13.0%) among latina women in our sample slightly higher than national estimates for latina women (9%-10%). we did not find an association between gwg status at time of delivery and pregnancy length as previously found. in addition, we did not find ethnic differences in low or high birth weight, which is in contrast to prior data indicating that puerto rican latinas have some of the highest rates of low birth weight neonates and preterm births in the us. multiple factors not assessed in this retrospective cohort study (e.g., prior preterm births, gestational diabetes mellitus) may contribute to and account for differences in birth outcomes observed in this study compared to previous studies. in addition, conventional measures of gwg may introduce bias when studying gwg - preterm birth associations. additional studies with larger, ethnically diverse samples are needed to elucidate predictors driving racial / ethnic disparities in birth weight outcomes. study strengths include the sample 's ethnic and socioeconomic diversity (i.e., white / latina women, public / commercial insurance, and hospital clinics / private provider) and inclusion of women who delivered pre- and full - term (previous studies have been limited to women who delivered full - term) [2, 7 ]. although no data were available on place of birth, most latinos in the region where the study was conducted are of puerto rican descent, a largely understudied population with considerable health disparities, including infant mortality. study limitations include the retrospective study design and the use of existing medical record data (with data gathered within the context of clinical activities rather than by trained research staff). however, all providers completed similar maternal and prenatal medical forms, which were routinely filed in the hospital medical record database prior to delivery. participants ' self - reported prepregnancy weight (as opposed to prepregnancy weight measured in a clinical or research setting) was used to determine gwg status. however, the iom guidelines are based on studies that similarly use self - reported prepregnancy weight, and self - reported prepregnancy weight has been found to be highly correlated with clinically measured weight [4042 ]. information available on smoking patterns during pregnancy (i.e., number of cigarettes, quit date) was restricted. furthermore, smoking status data was collected in the context of the first prenatal appointment and may be subject to social desirability bias and may only reflect smoking status at the first prenatal visit. however, the prevalence of smoking in our sample (19%) is consistent with smoking rates among white [2, 3, 32, 33 ] and latina pregnant women in previous studies. presence of gestational diabetes, shown to be associated with birth weight [44, 45 ], was not controlled for. women without a first - trimester prenatal visit and with missing prepregnancy bmi data were excluded from analysis ; as systematic biases might exist between women who were or were not missing these data, findings may not be representative of the larger population from which the study sample was drawn. study findings may not be generalizable to other (non - puerto rican) latino subgroups. lastly, the study was not adequately powered to examine ethnic differences in pregnancy outcomes by gwg status ; thus, results of gwg associated with outcomes of interest by ethnicity are exploratory. understanding factors that contribute to inadequate and excessive gwg is critical to the development of interventions that seek to optimize recommended gwg. additional researches on racial / ethnic differences in the influence of early gwg on gwg and other maternal and neonatal outcomes are needed to guide the development of interventions tailored for socioeconomically and ethnically diverse populations. | this study examined racial / ethnic differences in gestational weight gain (gwg) predictors and association of first - trimester gwg to overall gwg among 271 white women and 300 latina women. rates of within - guideline gwg were higher among latinas than among whites (28.7% versus 24.4%, p < 0.016). adjusted odds of above - guideline gwg were higher among prepregnancy overweight (or = 3.4, ci = 1.86.5) and obese (or = 4.5, ci = 2.39.0) women than among healthy weight women and among women with above - guideline first - trimester gwg than among those with within - guideline first - trimester gwg (or = 4.9, ci = 2.88.8). gwg was positively associated with neonate birth size (p < 0.001). interventions targeting prepregnancy overweight or obese women and those with excessive first - trimester gwg are needed. |
wireless capsule endoscope (wce) was invented at the beginning of this century.1 from the day on which it was applied in a clinical test, a great potential was unfolded before our eyes in the diagnosis of small intestinal diseases thanks to its comfortable, painless, and less - invasive exploration of gastrointestinal (gi) tract with a swallowable miniaturized on - board camera.16 following the invention, several capsule endoscopes become commercialized, which opens a new era of small intestine inspection.6 the main limitation of wce is its passive and random motion manner, as it is driven by natural peristalsis of the gi tract and gravity.710 so some interested area could be missed,11 in addition, reviewing thousands of pictures is also a burden for a physician. if the controllability for wce becomes real, the clinical diagnostic efficacy will be greatly improved. more benefits of a controllable wce might include reduced energy consumption, shortened inspection time and less pictures, and decreased retention risk.12 a potential propelling approach is based on an imbedded magnet with the magnetization perpendicular to the capsule s central axis. with the coupling of external revolving magnetic fields, the capsule spins about its axis by magnetic torque. as the spiral thread is attached to the capsule s surface, the rotation can be transformed to translational motion.13,14 and the spiral - type capsule has an advantage that the maximum magnetic torque passing to the capsule is proportional to the magnetic field strength, which decreases slower than the gradient magnetic field over the distance.14 some research work about friction and mechanical properties of some parts of gi tract were reported. wang pulled dummy capsules by a string sliding segments of porcine small bowel.15 the resistant forces vary from 20 to 100 mn as the capsule diameter is in the range of 813 mm and the moving speed is 0.5 mm / s. zhou measured torque and friction.14 natali measured the resistant force against the propulsion of wce through the coupling of the external magnet.16 aforementioned work is of benefit to the understanding of the properties of the gi tract. the magnetic permeability of the human body is very close to that of vacuum, so human body will not change the distribution of static magnetic field.17 we propose that a cylindrical magnet ring radially magnetized as s (south) and n (north) poles covers outside the commercial wce, leaving the dome parts uncovered. the magnet ring is covered by biomedical polymer material, avoiding direct contact with mucus. a spiral structure is mounted on the surface of wce, converting the rotation into straight motion. the movement of spiral - type wce rotating inside the gi tract was investigated in a realistic manner. a small magnetic driving instrument (mdi) was specially designed for experiment inspired by lien.18 the segments of porcine large intestine were deployed for the ex vivo experiments. four capsule dummies were fabricated for propulsion efficiency and moving speed exploring, and it can be used as reference when developing a real wce. each capsule, the hollow cylindrical permanent magnet (magnet ring), radially magnetized as s and n poles (figure 1a), was filled with ethylene - vinyl acetate copolymer at the both ends of the magnet ring to form domes, simulating the shape of commercial wce. ndfeb has a stronger magnetic field in the ordinary environment, so we chose ndfeb (grade : n38) as a raw material for magnet rings. the parameters of the magnet ring are listed in table 1, and the magnetic flux intensities were measured using tesla meter (ht20 ; shanghai hengtong cidian technology co, ltd, shanghai, people s republic of china). to ensure authenticity, the dimensions of magnet rings are made to approximate those of commercial wces on the market. a segment of copper wire coated with ethylene - vinyl acetate copolymer was wound on the surface of each magnet ring and acted as spiral structure. the winding part was only within the cylindrical magnet surface, as shown in figure 1b. two diameters of spiral line were tentatively chosen, and the length of each dummy capsule is described in table 2. the small mdi included a stepper motor, a motor driver, a controller, a power supplier, and two same bar permanent magnets (length : 5 cm ; width : 0.8 cm ; height : 0.6 cm), which were also made of ndfeb (grade : n38 ; maximum magnetic flux intensity of poles : 595 mt). two bar magnets were fixed on the axis of the motor with opposite pole close together, and the stepper motor was used to rotate the bar magnets to generate rotational magnetic fields. the rotational speed of the stepper motor was adjusted conveniently by changing the parameters of imbedded program. in addition, the rotational speed of stepper motor was accurately measured using an infrared rotation meter (dt-2234b ; lutron, taibei, taiwan). a piece of reflecting mark was stuck on the surface of the connector to implement noncontact measurement. the experiments were carried out in the ordinary lab at room temperature of 25c. to guarantee the freshness of the intestine, the intestines of pig were bought in the early morning from the slaughterhouse. it was approximately 1 hour after the pork intestine was pulled out that the experiments began. to keep the characteristic of the live specimen, the normal saline was sprayed on the surface of the intestine every 20 minutes. the torque generated by the rotational magnetic fields will pass to the magnetic ring. to find what torque can rotate the capsule, the rigid rod was fastened to one end of the capsule, and the other end of the rod was connected to the handy torque gauge (htg2 - 5n ; imada, toyohashi, japan), which was able to display the real - time data in the indicator. through rs232c cable cb-204 and application software provided by imada, the real - time data were transferred to pc for storing and further processing. suppose the parameters of magnet ring are as follows : the length l, inner radius ri, outer radius ro, and magnetization m0 (magnetic dipole moment per unit volume). then the magnetic dipole moment m of the magnet ring can be formulated as m=vm0dv = m0(ro2ri2)l(1) the magnetic torque t produced on a dipole moment m by the applied magnetic flux intensity b causes m to align with b and is expressed by t = mb(2) because the magnetic fields produced by both the magnet ring and rotational magnet are not uniform, the magnetic torques vary from 0 to maximum. the torques change slightly with different capsules, cap1 is used to measure the torques to understand the general magnitude and variation trend. the distance between the center of the capsule and the surface of rotational magnet was fixed. when the motor rotates one circle, the maximum value in one cycle was automatically recorded by torque meter. from table 3, we can infer what torque can rotate the capsule when the distance is determined. figure 4 illustrates that the torque decreases quickly with the increasing distance, which is reliable due to quick decrease of the magnetic flux intensity b over distance. rotational synchronization of capsule and stepper motor reflects the efficiency of rotation propelling. to implement measurement of rotational speed of the capsule, the reflecting mark a short segment of porcine large intestine was put in the half pipe, and the capsule was put on the surface of arc - shape large intestine. when the capsule rotated, the infrared of the rotation meter pointed at the reflecting mark, and then the rotation speed of the capsule was automatically recorded. the rotational speeds of stepper motor were recorded as follows : 9.7, 24.6, 37.3, 57.6, 78.3, 98.7, 117.1, and 128.9 rpm. four dummy capsules were propelled by these rotational speeds separately. due to trembling of cap2 and cap4 when the rotational speed of motor exceeded 70 rpm, the rotational speed of capsule can not be correctly recorded. as the diameters of a spiral line of both cap2 and cap4 are two times larger than cap1 and cap3, we cautiously infer that the diameter of spiral line is larger. figure 6 illustrates that the rotation speeds of cap1 and cap3 highly match the rotational speeds of the stepper motor. the rotational speeds of cap2, cap4, and stepper motor are also highly matched, though the rotational speed of capsule remains unknown when the rotational speeds of stepper motor exceed 60 rpm. due to no reference to the length of porcine large intestine, after several times of trials, we found that 40 cm intestine is suitable for measurement. the large intestine with 40 cm was cut open and put into the half pipe, keeping arc - shaped, and the capsule was placed at the end of the intestine, as illustrated in figure 7. for each capsule, the stepper motor s rotational speed varied from 9 to 216 rpm. when rotating, the stepper motor moved forward under the half pipe at the speed of 0.52 cm / s, driving the capsule to rotationally move forward. the three measurements of minimum time were recorded, and the average value was used to calculate the translational velocity of the capsule. the asterisk means that the capsule hardly moves forward at the rotational speed of 9 rpm. as shown in figure 8, the translational speed of cap1 almost increases linearly with increasing rotational speed when the rotational speed of the stepper motor is less than 80 rpm. when the speed of the stepper motor exceeds 80 rpm, the translational speed of cap1 keeps stable. the translational speeds of cap2, cap3, and cap4 increase slowly when the stepper motor s rotational speeds are less than 80 rpm, and we observed that their stabilities are not so good as cap1. from the view of propelling efficiency, it is delightful because the trembling can help the capsule to overcome the resistance produced by the fold of the intestine. we preliminarily conclude that cap1 is better than others from the aspects of the dimension and helical line. the torque generated by the rotational magnetic fields will pass to the magnetic ring. to find what torque can rotate the capsule, the rigid rod was fastened to one end of the capsule, and the other end of the rod was connected to the handy torque gauge (htg2 - 5n ; imada, toyohashi, japan), which was able to display the real - time data in the indicator. through rs232c cable cb-204 and application software provided by imada, the real - time data were transferred to pc for storing and further processing. suppose the parameters of magnet ring are as follows : the length l, inner radius ri, outer radius ro, and magnetization m0 (magnetic dipole moment per unit volume). then the magnetic dipole moment m of the magnet ring can be formulated as m=vm0dv = m0(ro2ri2)l(1) the magnetic torque t produced on a dipole moment m by the applied magnetic flux intensity b causes m to align with b and is expressed by t = mb(2) because the magnetic fields produced by both the magnet ring and rotational magnet are not uniform, the magnetic torques vary from 0 to maximum. the torques change slightly with different capsules, cap1 is used to measure the torques to understand the general magnitude and variation trend. the distance between the center of the capsule and the surface of rotational magnet was fixed. when the motor rotates one circle, the maximum value in one cycle was automatically recorded by torque meter. from table 3, we can infer what torque can rotate the capsule when the distance is determined. figure 4 illustrates that the torque decreases quickly with the increasing distance, which is reliable due to quick decrease of the magnetic flux intensity b over distance. rotational synchronization of capsule and stepper motor reflects the efficiency of rotation propelling. to implement measurement of rotational speed of the capsule, the reflecting mark a short segment of porcine large intestine was put in the half pipe, and the capsule was put on the surface of arc - shape large intestine. when the capsule rotated, the infrared of the rotation meter pointed at the reflecting mark, and then the rotation speed of the capsule was automatically recorded. the rotational speeds of stepper motor were recorded as follows : 9.7, 24.6, 37.3, 57.6, 78.3, 98.7, 117.1, and 128.9 rpm. four dummy capsules were propelled by these rotational speeds separately. due to trembling of cap2 and cap4 when the rotational speed of motor exceeded 70 rpm, the rotational speed of capsule can not be correctly recorded. as the diameters of a spiral line of both cap2 and cap4 are two times larger than cap1 and cap3, we cautiously infer that the diameter of spiral line is larger. figure 6 illustrates that the rotation speeds of cap1 and cap3 highly match the rotational speeds of the stepper motor. the rotational speeds of cap2, cap4, and stepper motor are also highly matched, though the rotational speed of capsule remains unknown when the rotational speeds of stepper motor exceed 60 rpm. due to no reference to the length of porcine large intestine, after several times of trials, we found that 40 cm intestine is suitable for measurement. the large intestine with 40 cm was cut open and put into the half pipe, keeping arc - shaped, and the capsule was placed at the end of the intestine, as illustrated in figure 7. for each capsule, the stepper motor s rotational speed varied from 9 to 216 rpm. when rotating, the stepper motor moved forward under the half pipe at the speed of 0.52 cm / s, driving the capsule to rotationally move forward. the three measurements of minimum time were recorded, and the average value was used to calculate the translational velocity of the capsule. the asterisk means that the capsule hardly moves forward at the rotational speed of 9 rpm. as shown in figure 8, the translational speed of cap1 almost increases linearly with increasing rotational speed when the rotational speed of the stepper motor is less than 80 rpm. when the speed of the stepper motor exceeds 80 rpm, the translational speed of cap1 keeps stable. the translational speeds of cap2, cap3, and cap4 increase slowly when the stepper motor s rotational speeds are less than 80 rpm, and we observed that their stabilities are not so good as cap1. from the view of propelling efficiency, it is delightful because the trembling can help the capsule to overcome the resistance produced by the fold of the intestine. we preliminarily conclude that cap1 is better than others from the aspects of the dimension and helical line. the spiral - type capsule has the ability to rotationally move forward at the speed of over 1 cm / s. the total intestine of an adult is approximately 10 m. if the capsule advances at this speed, less than 20 minutes will be cost when the capsule passes through the total intestine. when the capsule rotationally moved forward in the experiment, the distance between the external magnet and capsule was kept approximately 3.5 cm, which is challenging for the obese people. due to fast decay of the magnetic field strength of permanent magnet over distance, the torque generated by the permanent magnet quickly decreases, so extending the effective distance of mdi is essential. furthermore, the peristalsis of the living intestine may resist against the movement of the capsule, even push back the capsule, we will further investigate the motion of the capsule after approval. thus, we need experimental investigations to determine the appropriate lead angle and the diameter of the spiral line for capsule to move in the living intestine. the mucus, water, and debris in the intestine may protect the wall of intestine in some degree when the capsule rotates. however, we found that the rotation of spiral structure will push forward some mucus, water, and debris. further investigations are needed in the future to know whether the removal of mucus has bad influences on living body physiologically. the straight movement of the spiral - type capsule is experimentally demonstrated in the viscoelastic intestine. the rotation of spiral - type capsule is converted to translational movement effectively, and the translational speed of capsule can exceed 1 cm / s. the validity of this driving approach in the winding intestine and optimal parameters of spiral structure will be investigated further. | wireless capsule endoscope achieved great success, however, the maneuvering of wireless capsule endoscope is challenging at present. a magnetic driving instrument, including two bar magnets, a stepper motor, a motor driver, a motor controller, and a power supplier, was developed to generate rotational magnetic fields. permanent magnet ring, magnetized as s and n poles radially and mounted spiral structure on the surface, acted as a capsule. the maximum torque passing to the capsule, rotational synchronization of capsule and motor, and the translational speed of capsule, were measured in ex vivo porcine large intestine. the experimental results illustrate that the rotational movement of the spiral - type capsule in the intestine is feasible and the cost of the magnetic driving equipment is low. as a result, the solution is promising in the future controllability. |
normal pericardium is a double - walled sac that contains the heart and the roots of the great vessels. the pericardium is composed of two different layers ; an outer fibrous parietal pericardium and an inner visceral pericardium.1) the inner visceral pericardium is a serous - type membrane and is located immediately outside of the myocardium.2)3) the pericardium prevents sudden dilatation of the heart, especially the right chamber, and displacement of the heart and great vessels, minimizes friction between the heart and surrounding structures, and prevents the spread of infection or cancer from the lung or pleura. the pericardium also contributes to diastolic coupling between the two ventricles.3)4) in between the parietal and visceral pericardium, there is a pericardial cavity filled with 10 - 50 cc of fluid, an ultrafiltrate of plasma that is produced by the visceral pericardium. pericardial effusion can develop in patients with virtually any condition that affects the pericardium, including acute pericarditis and a variety of systemic disorders.1)5) the clinical causes of pericardial effusion are very diverse and include malignancies of other organs, pulmonary tuberculosis, chronic renal failure, thyroid disease, autoimmune disease, and iatrogenic and idiopathic causes (table 1).5 - 7) the development of a pericardial effusion may have important implications for the prognosis (as in patients with intrathoracic malignancy) or diagnosis (as in myopericarditis or acute pericarditis), or both (as in dissection of the ascending aorta).6) when a pericardial effusion is initially or incidentally detected, a major concern for clinicians may be its etiology. in a majority of cases, the etiology of the effusion can be presumed from the underlying condition of the patient. although the exact etiology of pericardial effusion can be identified by invasively - obtained pericardial fluid or tissue, an invasive procedure, like pericardiocentesis, is only indicated when the effusion is large or symptomatic, the effusion is accompanied by tamponade, or the cause of the effusion is questionable. there is some discrepancy in the etiologies of pericardial effusion, requiring pericardiocentesis between countries or centers. a review of many articles from throughout the world shows that the relative frequency of different etiologies is mainly affected by the decade, local epidemiology, hospital volume, and the diagnostic protocol.6)7) the etiology of pericardial effusion in korea and other countries is summarized in table 2.8 - 15) in korea, lung cancer and pulmonary tuberculosis are predominant causes of large pericardial effusion.8 - 10) sagrista - sauleda.13) reported that when an etiology is not apparent, the clinical indices, including the size of the effusion, the presence of inflammatory signs, and cardiac tamponade, may be useful in suggesting a possible etiologic category. for example, severe effusions without inflammatory signs or tamponade were significantly associated with chronic idiopathic pericardial effusion. m - mode and 2-dimensional doppler echocardiography is the most effective technique, and is the gold standard for the diagnosis of pericardial effusion, because it is sensitive, specific, noninvasive, and easily made available at the bedside.16) pericardial effusion can be detected as an " echo - free space " on 2-dimensional echocardiography (fig. 1).1 - 5) small collections of pericardial fluid, which can be physiologic (25 to 50 ml), may be visible during ventricular systole. when the amount of effusion is more than 50 ml, an echo - free space persists throughout the cardiac cycle. when a pericardial effusion is detected by echocardiography, the next step is to assess the size of the effusion, its location, hemodynamic importance, and associated diseases.4)17) a pericardial effusion is not always uniformly distributed around the heart. initially, small effusions are evident over the posterobasal left ventricle ; however, as the fluid volume increases, it gradually spreads anteriorly, laterally, and behind the left atrium. ultimately, the separation becomes circumferential and appears as " swinging heart ", which is a sign of a large pericardial effusion and possibly cardiac tamponade.4) despite the fact that there is a large amount, the pericardial effusion does not surround the posterior portion of the heart. therefore, the amplitude of the p wave is not changed, in spite of a large pericardial effusion or after pericardiocentesis (fig. 2).18) several grading systems have been developed, based on the size of the pericardial effusion. however, a generally accepted system is the effusion graded as minimal (scanty), small, moderate, or large. for circumferential pericardial effusions, any pericardial effusion with less than 5 mm of pericardial separation in diastole (corresponding to a fluid volume of 50 to 100 ml) is defined as minimal ; 5 to 10 mm of separation as small (corresponding to a fluid volume of 100 to 250 ml) ; 10 to 20 mm of separation as moderate (corresponding to a fluid volume of 250 to 500 ml) ; and greater than 20 mm separation as large (corresponding to a fluid volume greater than 500 ml) (fig.. however, even the diffused and circumferential effusion dimensions of the echo - free space may be different in the views examined ; therefore, it is more correct and easier to measure and annotate the dimension of the effusion and to report where it has been evaluated (e.g., 12 mm in the left ventricular lateral wall in the apical four - chamber view ; 10 mm along the right atrium in the subcostal view). this methodology not only facilitates the definition of effusion size, but also allows follow - up studies by detecting changes in the amount of pericardial fluid after therapy.17) except for the epicardial fat, the abnormal masses attached on the epicardial surface or floating in the pericardial space must also be reported. it may be an infiltrative metastatic mass, inflammatory fibrin strands, pus, or a blood clot (fig. other imaging modalities, such as computed tomography (ct) or magnetic resonance imaging (mri), may be used to identify the characteristics of pericardial effusion and tamponade in the presence of a technically - limited echocardiographic study.6)7)19) however, the clinical utility of ct and mri is questioned because of the high positive predictive value of echocardiography with potential safety concerns in acutely ill patients. currently, these modalities have adjunctive roles to echocardiography, especially in situations that show atypical hemodynamics, presence and severity of tamponade are doubtful, or when there are other unexplained conditions.19) for instance, in the case of pericardial effusion associated with intrathoracic malignancies, such as lung, breast, or esophageal cancer, chest ct might be useful for understanding the disease progression at a glance. cardiac tamponade is a life - threatening, slow or rapid compression of the heart due to the pericardial accumulation of fluid, pus, blood, clots, or gas as a result of effusion, trauma, or rupture of the heart.20)21) the normal pericardium can stretch to accommodate increases in the pericardial volume. once the pericardium has been stretched to its limit, by accumulating effusion, ongoing accumulation of pericardial fluid into a closed space increases the intrapericardial pressure. when the intra - pericardial pressure becomes high enough to impede cardiac filling, cardiac function therefore, the definition of cardiac tamponade is the state when the heart is compressed due to fluid accumulation and increased intrapericardial pressure, resulting in cardiogenic shock and circulatory collapse.20) in the physiology of tamponade development, a complex interaction of factors influences the ultimate physiologic consequences of pericardial effusion, in any given patient. these factors include the pericardial pressure / volume relationship, the rapidity of fluid accumulation, underlying cardiac pathology (particularly hypertrophy and shunts), and systemic volume status. it is well understood that small acute pericardial effusions (occurring most commonly post - intervention or traumatically) can lead to dramatic tamponade physiology when fluid accumulates rapidly ; whereas, moderate - sized or even large pericardial effusions that accumulate slowly can be well tolerated, hemodynamically (fig. 5).20)21) therefore, large pericardial effusions or the swinging motion of the heart is not always present in cardiac tamponade. on the contrary, a localized compressing effusion may lead to dramatic hemodynamic consequences without producing classical echocardiographic indications of tamponade.4)22) the most common cause of cardiac tamponade reported is malignancy, which is involved in > 50% of all tamponade cases. especially lung cancer was involved in > 70% of cardiac tamponade of malignant origin.21) although cardiac tamponade is considered a clinical diagnosis, clinical findings like dyspnea, hypotension, tachycardia, elevated jugular venous pressure, and pulsus paradoxus, are known to have limited sensitivity and specificity.20) echocardiography is the most useful diagnostic tool for evaluating patients with cardiac tamponade, and it should be performed without delay in patients if suspected.1)23) the most characteristic echocardiographic findings that suggest cardiac tamponade is diastolic collapse of the free walls of the right atrium, and/or the right ventricle.1)7)24) any cardiac chamber can be collapsed, but it usually occurs on the right - sided chambers because both the right atrium and right ventricle are compliant and low pressure chambers.1) right atrial compression for more than one third of the cardiac cycle (late diastole) is highly sensitive and specific for cardiac tamponade (fig. 6a).1)7)22)25)26) right ventricular compression in early diastole is less sensitive for the presence of cardiac tamponade than ra diastolic collapse, but is very specific for cardiac tamponade (fig. 6b).1)7)27 - 30) rv collapse may not occur when the rv is hypertrophied or when its diastolic pressure is greatly elevated. left atrial chamber collapse can be seen in about 25% of patients with hemodynamic compromise, and is very specific for cardiac tamponade. left ventricular collapse is less common, since the wall of the left ventricle is more muscular, but can be seen under special conditions, such as localized postsurgical tamponade or severe pulmonary hypertension. reciprocal changes in the left and right ventricular volumes occur with respiration in cardiac tamponade. doppler echocardiography has been used to estimate respiratory variation in mitral and tricuspid diastolic inflow velocity. in accordance with pulsus paradoxus, a more exaggerated respiratory variation in inflow velocity, representing an inspiratory decrease in peak mitral inflow velocity 30%, and an inspiratory increase of peak tricuspid inflow velocity 50%, would suggest an increased ventricular interdependence and presence of cardiac tamponade (fig. 6c).1)7)31)32) dilatation of the inferior vena cava (ivc) and < 50% reduction in the diameter of the dilated ivc during inspiration, so called ivc plethora, reflecting a marked elevation in the central venous pressure is frequently seen in patients with cardiac tamponade.1)7)33) ivc plethora was associated with pulsus paradoxus and was present in 92% of those with pericardial effusion, who required pericardial drainage. collapse of the right - sided chambers is a sensitive indicator of tamponade, but abnormalities in cardiac filling are a more specific finding of tamponade.34) although cardiac tamponade may be diagnosed, using the above findings, clinicians should be aware that echocardiography has some limitations for diagnosis and follow - up of cardiac tamponade. for example, severe hypovolemia or large pleural effusions can cause diastolic chamber collapse. additionally, disease states that increase right - sided cardiac pressures, such as pulmonary hypertension or pulmonary thromboembolism, may prevent diastolic chamber collapse.35) cardiac tamponade is not an " all - or - none " phenomenon, but rather a spectrum of findings.6) therefore, for the final diagnosis of cardiac tamponade, clinicians should correlate the echocardiographic signs of tamponade (rv collapse, ra collapse, respiratory alteration of mitral and tricuspid flow, and ivc plethora) with the symptoms and signs of clinical tamponade (dyspnea, tachycardia, jugular venous distension, pulsus paradoxus, hypotension, and shock).6) percutaneous needle pericardiocentesis has been the most useful therapeutic procedure for the early management of large, symptomatic pericardial effusion or cardiac tamponade, and it continues to be used as a diagnostic procedure in some patients with asymptomatic pericardial effusion, such as chronic idiopathic effusion.7)17)36)37) before, during, and after the percutaneous pericardiocentesis, transthoracic echocardiography guidance is essential.36)38) if the pericardiocentesis is performed at bedside without echocardiographic guidance, the risk of threatening complications like bleeding or shock have been reported to be as high as 20%. in contrast, echocardiographic guidance increases the success rate of pericardiocentesis by reducing these complications.7)11) in korea, the success rate of echocardiography - guided pericardiocentesis was about 99%.8)9) when deciding to perform pericardiocentesis, many clinical and echocardiographic factors must be comprehensively considered. these factors include the amount and location of the effusion, hemodynamics on echocardiography, sufficient margins of the echo free space so as to prevent laceration, clinical indication and urgency, underlying etiologies, and bleeding tendency. recently, halpern.39) suggested a " pericardial effusion scoring index " for deciding whether to perform pericardiocentesis. the scoring index consists of 3 components obtained at initial presentation ; effusion size on echo, echocardiographic assessment of hemodynamics, and etiology of effusion. authors reported that percutaneous pericardiocentesis could be performed when the score was 4 or above. 1) check clinical indications and medical history, such as taking anti - platelet or anti - coagulation drugs, and get a consent form.2) positioning and echocardiographic imaging a) position the patient in the semi - fowler position in bed.b) perform 2d echocardiographic imaging at the apical view (fig. 7c) to gain insight into the effusion.40)41) 3) determination of puncture site a) choose sites with the biggest echo - free space for safe needle entry, and mark it using a pen or nail tip on the site (fig. 4) preparation of puncture site a) prepare all requisite tools for the centesis on the table (fig. 7f).b) cover the patient with a surgical drape and the patient 's eyes with an eye patch to reduce tension and anxiety (fig. 5) pericardiocentesis a) perform a preliminary exploration with the local anesthetic needle (21 gauge) to confirm the direction of the needle approach and to feel the nature of the effusion.b) put the puncture needle (18 gauge) to the tip of the puncture syringe.c) gently insert and advance the puncture needle from the skin of the puncture site toward the heart in the breath holding state. the puncture needle must maintain the direction that was determined during the preliminary exploratory test (fig. 7i).d) feel the " pop " moment at the puncture and observe negatively drained fluid in the syringe (fig. 7j).e) stop the advancing puncture needle and hold the needle with your fingers to prevent further advancement. insert a smooth tip guidewire through a back - hole in the syringe, sufficiently into the pericardial space (fig. 7n), insert a double lu men indwelling catheter over the guidewire into the pericardial space (fig. 7o).h) remove the guidewire with the remaining indwelling catheter in the pericardial space.i) confirm the success of the procedure by manual drainage with a syringe (fig. 7q) or a saline bubble test with echocardiography. the patient 's reduced or relieved symptoms soon after the drainage, even by a small amount, is additional evidence of success.j) suture the catheter on the skin and continue to drain the effusion into a bottle (fig. 1) check clinical indications and medical history, such as taking anti - platelet or anti - coagulation drugs, and get a consent form. 2) positioning and echocardiographic imaging a) position the patient in the semi - fowler position in bed.b) perform 2d echocardiographic imaging at the apical view (fig. 7c) to gain insight into the effusion.40)41) a) position the patient in the semi - fowler position in bed. 7c) to gain insight into the effusion.40)41) 3) determination of puncture site a) choose sites with the biggest echo - free space for safe needle entry, and mark it using a pen or nail tip on the site (fig. a) choose sites with the biggest echo - free space for safe needle entry, and mark it using a pen or nail tip on the site (fig. 4) preparation of puncture site a) prepare all requisite tools for the centesis on the table (fig. 7f).b) cover the patient with a surgical drape and the patient 's eyes with an eye patch to reduce tension and anxiety (fig. b) cover the patient with a surgical drape and the patient 's eyes with an eye patch to reduce tension and anxiety (fig. 7 5) pericardiocentesis a) perform a preliminary exploration with the local anesthetic needle (21 gauge) to confirm the direction of the needle approach and to feel the nature of the effusion.b) put the puncture needle (18 gauge) to the tip of the puncture syringe.c) gently insert and advance the puncture needle from the skin of the puncture site toward the heart in the breath holding state. the puncture needle must maintain the direction that was determined during the preliminary exploratory test (fig. 7i).d) feel the " pop " moment at the puncture and observe negatively drained fluid in the syringe (fig. 7j).e) stop the advancing puncture needle and hold the needle with your fingers to prevent further advancement. insert a smooth tip guidewire through a back - hole in the syringe, sufficiently into the pericardial space (fig. 7n), insert a double lu men indwelling catheter over the guidewire into the pericardial space (fig. 7o).h) remove the guidewire with the remaining indwelling catheter in the pericardial space.i) confirm the success of the procedure by manual drainage with a syringe (fig. 7q) or a saline bubble test with echocardiography. the patient 's reduced or relieved symptoms soon after the drainage, even by a small amount, is additional evidence of success.j) suture the catheter on the skin and continue to drain the effusion into a bottle (fig. a) perform a preliminary exploration with the local anesthetic needle (21 gauge) to confirm the direction of the needle approach and to feel the nature of the effusion. b) put the puncture needle (18 gauge) to the tip of the puncture syringe. c) gently insert and advance the puncture needle from the skin of the puncture site toward the heart in the breath holding state. the puncture needle must maintain the direction that was determined during the preliminary exploratory test (fig. d) feel the " pop " moment at the puncture and observe negatively drained fluid in the syringe (fig. e) stop the advancing puncture needle and hold the needle with your fingers to prevent further advancement. insert a smooth tip guidewire through a back - hole in the syringe, sufficiently into the pericardial space (fig. 7n), insert a double lu men indwelling catheter over the guidewire into the pericardial space (fig. i) confirm the success of the procedure by manual drainage with a syringe (fig. 7q) or a saline bubble test with echocardiography. the patient 's reduced or relieved symptoms soon after the drainage, even by a small amount, is additional evidence of success. j) suture the catheter on the skin and continue to drain the effusion into a bottle (fig. there are 3 approaches to needle entry during pericardiocentesis ; left parasternal, subxyphoid, and left apical.37)41) among these, the left parasternal approach seems to be preferred in the era of echocardiography - guided pericardiocentesis, because the left parasternal view provides a more direct route to the largest echo free space and better safety than other approaches. using the left parasternal approach, the puncture needle is inserted close to the sternum, usually in the left 5th or 6th intercostal space. this approach is associated with possibly a higher risk of pneumothorax than with the subxyphoid approach.41)42) the puncture needle during the subxyphoid approach is inserted at an angle between the xiphisternum and left costal margin, towards the left shoulder at a 15 to 30 degree angle to the skin.20) this approach has been performed when echocardiography is not available, in the cardiac catheterization room with ecg monitoring, or in emergent situations. this route is extrapleural and avoids the coronary, pericardial, and internal mammary arteries. injuries to the pleura, liver, or stomach, irritation to the diaphragm and phrenic nerve resulting in bradycardia and shock, and higher procedure - related mortality have been reported with this approach than with others.7)41) in the left apical approach, the puncture needle is inserted into the intercostal space outside of the left nipple, where the left ventricular apical beating is touched, and is toward the right shoulder. during this approach, the apex can easily be pierced, and evoke ventricular fibrillation ; thus, it is not indicated in emergent situations and must be performed under the guidance of echocardiography.41) the choice of direction of approach must be decided by an experienced clinician, after considering if there is a safe enough margin of echo free space, the patient 's position, and clinical situation. a major complication of percutaneous pericardiocentesis includes laceration of the heart and coronary arteries, hemothorax and pneumothorax, ventricular tachyarrhythmia, and vasovagal response.7) during pericardiocentesis, clinicians must be attentive to the important anatomic structures in the way of the puncture needle approach, including the internal thoracic arteries (located 0.5 to 2 cm lateral to the sternal edge), intercostal vessels (inferior border of the rib) and nerves, phrenic nerve in the diaphragm, pleura, lung parenchyma, and free wall of the right or left ventricle.41) aortic dissection is a major contraindication of pericardiocentesis. relative contraindications include uncorrected coagulopathy, anticoagulant therapy, and thrombocytopenia < 50000/mm, and small, posterior, and loculated effusions.7) surgical drainage, rather than percutaneous pericardiocentesis is preferred in the following situations : traumatic hemopericardium, purulent pericarditis, recurrent malignant effusion, loculated effusion in the posterior side of the heart, a need for pericardial biopsy with drainage for diagnosis, and coagulopathy or thrombocytopenia.43 - 45) pericardial effusion can develop in patients with virtually any condition that affects the pericardium, including acute pericarditis, malignancies, pulmonary tuberculosis, chronic renal failure, thyroid disease, autoimmune disease, or iatrogenic and idiopathic causes. the causes of large pericardial effusions, requiring invasive pericardiocentesis or pericardiotomy, vary according to the times, status of the countries, and the location, size, and facilities of the hospital. especially in korea, transthoracic echocardiography is the most important tool for the diagnosis, grading, pericardiocentesis procedure, and follow up for pericardial effusion. clinicians should understand the tamponade physiology, especially cardiac tamponade that can develop without large pericardial effusion or swinging heart. in addition, clinicians should correlate the echocardiographic findings of tamponade, such as right ventricular collapse, right atrial collapse, respiratory variation in the mitral and tricuspid flow, and ivc plethora, with the signs of clinical tamponade, such as hypotension or pulsus paradoxus. pericardiocentesis is lifesaving for cardiac tamponade, and indicated in cases where there is a large volume of pericardial effusion. | pericardial effusion can develop from any pericardial disease, including pericarditis and several systemic disorders, such as malignancies, pulmonary tuberculosis, chronic renal failure, thyroid diseases, and autoimmune diseases. the causes of large pericardial effusion requiring invasive pericardiocentesis may vary according to the time, country, and hospital. transthoracic echocardiography is the most important tool for diagnosis, grading, the pericardiocentesis procedure, and follow up of pericardial effusion. cardiac tamponade is a kind of cardiogenic shock and medical emergency. clinicians should understand the tamponade physiology, especially because it can develop without large pericardial effusion. in addition, clinicians should correlate the echocardiographic findings of tamponade, such as right ventricular collapse, right atrial collapse, and respiratory variation of mitral and tricuspid flow, with clinical signs of clinical tamponade, such as hypotension or pulsus paradoxus. percutaneous pericardiocentesis has been the most useful procedure in many cases of large pericardial effusion, cardiac tamponade, or pericardial effusion of unknown etiology. the procedure should be performed with the guidance of echocardiography. |
the reported constituents in the cigarette smoke are nicotine, polycyclic aromatic hydrocarbons (pah), nitrated pah, ben zo[a]pyrene, thiocynate, nitro - lactones, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo(g, h, i) perylene, dibenz(a, h)anthracene ; aromatic amines. most of these constituents are toxic, mutagenic and carcinogenic and are perhaps the most significant source of deadly chemical exposure and chemical - mediated diseases, such as ; cardiovascular disease, chronic obstructive pulmonary diseases (copd) and various types of cancers, mainly lung cancer in humans and according to an estimate of who, 5.4 million premature deaths are attributable to tobacco smoking throughout the world. the toxic constituents present in tobacco smoke are also present in the environmental tobacco smoke (ets) and become an indirect source to the nonsmokers. passive smoking (ps) or second hand smoke (shs) or ets is defined as the inhalation of tobacco smoke by nonsmokers against their will or as being the involuntary exposure to tobacco smoke. ishimine have reported that ps consists of 15% mainstream smoke and 85% side stream smoke. mainstream smoke is the smoke discharged by expiration after being filtered through the smoker 's lungs, while side stream smoke is the smoke that goes directly into the air from a burning cigarette. passive smoke contains > 50 chemicals identified as known and/or probable human carcinogens and many toxic and irritant agents. globally, 40% of children, 33% of male nonsmokers and 35% of female nonsmokers were exposed to ps. studies have also reported that nonsmokers with ps exposure have a 2.1 times greater risk of developing lung cancer compared with those without ps exposure. evidence linking ps to adverse health outcomes (respiratory diseases, cardiovascular effects and lung cancer) has accumulated over the past two decades. furthermore, exposure to ps is shown as one of the causes for early deaths. however ; despite of a different life - style and cultural back ground, there is a paucity of literature on exposure to ps among saudis, especially the students. unmindful of the impact of ps many of the ps suffer serious deteriorating effects on their health. hence, it was found imperative to focus the effects of ps among the students of college of applied medical sciences (cams) and highlight the possible deterrent steps that can be taken. a cross - sectional study was performed to identify factors associated with ps exposure among college students in saudi arabia. data was collected from the students of cams at king saud bin abdul - aziz university for health sciences in riyadh, saudi arabia. the data from non - smokers was collected by a questionnaire described by jaakkola and jaakkola, which included locations, sources, frequency of exposure to ps, besides, annoyance due to smoke. medical tests were conducted to measure breath, saturation of the hemoglobin and blood pressure. the parameters used for medical tests are (1) spirometry, which is the most common to conduct the pulmonary function test (pft), specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. the method of cooper and mitchell was used to assess the lung function test by spirometry (2) pulse oximeter to monitor the saturation of a patient 's hemoglobin. the method devised by jrgensen., and brand. the data from non - smokers was collected by a questionnaire described by jaakkola and jaakkola, which included locations, sources, frequency of exposure to ps, besides, annoyance due to smoke. medical tests were conducted to measure breath, saturation of the hemoglobin and blood pressure. the parameters used for medical tests are (1) spirometry, which is the most common to conduct the pulmonary function test (pft), specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. the method of cooper and mitchell was used to assess the lung function test by spirometry (2) pulse oximeter to monitor the saturation of a patient 's hemoglobin. the method devised by jrgensen., and brand. we found about 56 students (91.8%) out of 61 were exposed to ps during the last 2 months of questionnaire administration. exposure in estirah was the most common place reported by 67.2%, followed by exposure in the university campus (39.3%), coffee shop (29.5%), public area (26.2), car (21.3%) and home (14.8%) [figure 1 ]. among the sources of exposure, the highest was among friends (89%) followed by brothers (16%), teachers (13%), parents (11%), guests and other persons (9%, each category) [figure 2 ]. the frequency of exposure per month showed the highest was > 15 times (32.8%) followed by 1 - 5 times (29.3%), 5 - 10 times (17.2%), 10 - 15 times (15.5%) [table 1 ]. the levels of annoyance varied between 18, 44.3 and 37.7 (low, average and maximum levels, respectively [table 2 ]. the results were computed by comparing the predicted values for forced expiratory volume in 1 s / forced vital capacity (fev1/fvc) (15 times / month), the results showed > 15 times / month to be the highest followed by 1 - 5 times / month. the respiratory symptoms are related to repeated high peak exposure levels, while lung cancer may require cumulative exposure over long time periods. exposure to ets may cause acute exacerbation of asthma or development of lung cancer detected 10 - 20 years later. on the contrary, the duration and the exposure times in the present study are very less and correspond with the intensity of effects observed. on determination of the level of annoyance, only a limited number of ps showed tolerance to the smoke, while majority revealed that the smoke annoys them either to some extent or to extreme. literature reports suggest that the negative impact of ets is its odor, which is unpleasant for many ps. in addition to the smell the smoke has been found to be allergic, irritant to eyes and nose and causes headache and cough to some of the ps. the values obtained for different markers in the pft are found more than the predicted values for fev1/fvc (< 70%) and fev1 (50 - 80%), the observed spirometry is normal showing no indication of any respiratory disease. exposure to tobacco smoke at home is known to cause airway inflammation and altered cytokine regulation and has been identified as a cause of premature death and disease in nonsmokers. exposure to ets has been linked to a broad array of diseases, including asthma, copd, cardiovascular disease and cancer. exposure to ets, at work place, during the period june to december, adversely affects pulmonary function in adults. rizzi., in their study have reported exposure to ets is associated with lung function impairment. although adverse effects of ps are biologically plausible, it remains controversial, whether ets exposure is linked with chronic respiratory symptoms and occurrence of copd, including asthma. for the purpose of risk evaluation, ps is often regarded as low - dose cigarette smoking. nevertheless, since the physical, chemical and biological properties of mainstream smoke, inhaled by the smoker and ets, which is breathed by the passive smoker, are quite different, risk extrapolation from active smoking to ps is uncertain. determined by the pulse oximeter, the percent oxygen saturation in hemoglobin of ps was in the normal range. the seasoned smokers are known to have lower blood oxygenation levels, as the smoke inhaled damages the biological mechanisms needed to carry oxygen through the blood stream. the normal range obtained in the present study of ps is ascribed to a very short duration of exposure where the smoke was inhaled was much diluted. blood pressure profile is relevant to the disturbances in the heart rate variability which is one pathway by which the second hand smoke and air pollutants affect cardiovascular morbidity and mortality. felber dietrich., in their study have reported exposure to ets influence the rate variability and is a predictor of increased cardiac risk. taken together, the observed negative effects of ps observed in the present study are attributed to short duration of exposure with a limited frequency. since the properties of mainstream smoke and ets are quite different, risk extrapolation from active to ps is uncertain, especially during a short period. nevertheless, it can be deteriorating during a longer duration, hence ; the administrators, policy makers and tobacco control advocates may endorse policies to restrict smoking in shared areas, particularly working environment. in view of the health risks of many of chemical substances present in the tobacco smoke, studies are needed to determine biomarkers of exposure to ets constituents in body fluids, in addition to saliva, urine and blood of people who actively or passively are exposed to the toxic compounds. active researches into discovery of these methodologies are required.quantitative structure toxicity relationship may be included in the battery of tests to identify chemicals in the ets with a high probability of being toxic, mutagenic and/or carcinogenic before undertaking the biological toxicity assays.the use of an innovative tobacco - substitute and smoke dilution to reduce toxicant impact in cigarette smoke will diminish toxicity burden on the ps. hence, more reviews of literature on the subject and promotion of experimental cigarettes have to become part of the literature. in view of the health risks of many of chemical substances present in the tobacco smoke, studies are needed to determine biomarkers of exposure to ets constituents in body fluids, in addition to saliva, urine and blood of people who actively or passively are exposed to the toxic compounds. quantitative structure toxicity relationship may be included in the battery of tests to identify chemicals in the ets with a high probability of being toxic, mutagenic and/or carcinogenic before undertaking the biological toxicity assays. the use of an innovative tobacco - substitute and smoke dilution to reduce toxicant impact in cigarette smoke will diminish toxicity burden on the ps. hence, more reviews of literature on the subject and promotion of experimental cigarettes have to become part of the literature. | background : despite the recent campaigns to eliminate smoking, the rates are still increasing world - wide. exposure to passive smoking (ps) is associated with morbidity and mortality from awful diseases. although many college students smoke, little is known about their exposure to ps, common places and sources of exposures in saudi arabia.aim:the aim of the following study is to identify prevalence and magnitude of ps among college students, exposure time, locations, sources of exposure, investigate the effects and make recommendations.materials and methods : a cross - sectional study was performed to identify factors associated with ps exposure among students of college of applied medical sciences, riyadh.results:out of 61 students included in the study, 91.8% were found exposed to ps. exposure in hospitality venues (estirah) was the most common followed by other areas. among the sources of exposure, the highest was among friends and the least were parents and guests. the frequency of highest exposure per month was > 15 times and the lowest was 10 - 15 times. levels of annoyance varied between 18% and 37.7%, respectively. since the values obtained for different markers in the pulmonary function test are more than the predicted values, the observed spirometry is normal. the percent oxygen saturation in hemoglobin and blood pressure of ps were in normal range.conclusion:since the properties of mainstream smoke and environmental tobacco smoke are quite different, risk extrapolation from active to ps is uncertain, especially during a short period. nevertheless, it can be deteriorating during a longer duration, hence ; the administrators, policy makers and tobacco control advocates may endorse policies to restrict smoking in shared areas, particularly working environment. |
gaucher disease (gd) is the most common lysosomal storage disorder and is caused by a deficiency in the enzyme glucocerebrosidase (gcase). it is an autosomal recessive disorder that primarily affects the mononuclear phagocyte system by lipid accumulation (tayebi. patients typically manifest hepatosplenomegaly, hematological changes, anemia and orthopedic complications (grabowski 2008 ; choy and campbell 2011). gd is classified into three types, on the basis of the presence or absence of neurological involvement : type 1, the most common form, has no associated neurological symptoms ; type 2, or acute neuronopathic disease, displays severe neurological involvement leading to death within the first years of life ; type 3, or chronic neuronopathic gd, exhibits varying degrees of systemic involvement with at least one neurological manifestation (hruska. the gene encoding gcase, gba, is located on chromosome 1q2122 and comprises 11 exons encoding a 497 amino acid protein. so far, about 300 mutations of this gene have been identified, including frame - shift, point and splice site mutations as well as deletions, insertions and recombinant alleles (choy. 2007 ; hruska. 2008 ; choy and campbell 2011). regarding the phenotype, null, mild or severe, depending on the resulting level of gcase production. null mutations, such as c.84dupg (84gg), do not lead to any enzyme production. mild mutations, such as c.1226a > g (n370s), are only associated with type 1 disease. severe mutations, such as c.1448t > c (l444p), result in enzyme production and are usually associated with type 2 or 3 disease (beutler. 2005 ; campbell and choy 2012). findings from more studies have shown that gba is an important risk factor for parkinson s disease (pd). a small subset of gd patients with gba carriers developed parkinsonian symptoms including tremor, rigidity and bradykinesia (bembi. 2003) and were also associated with diffuse lewy body (lb) pathology in the brain (nishioka. this article reviews the present knowledge on the interaction of synuclein and gcase, with an emphasis on the pathogenesis and mechanism of gba - associated parkinsonism. parkinson s disease is the second most common neurodegenerative disorder, affecting 1 % of people over the age of 65 worldwide (depaolo. it is generally diagnosed after the age of 60 and causes motor dysfunctions, such as bradykinesia, resting tremor, rigidity and postural instability, but also affects autonomic functions and cognition (poewe 2008). the two pathological features of pd are the death of neurons in certain regions of the brain and accumulation of proteins and lipids into structures. the former leads to the clinical picture of tremor, stiffness, slowness and difficulties with posture, and the latter generates lbs inside surviving neurons (gai. these neuropathologic aggregates are also associated with other neurodegenerative disorders including dementia with lbs (dlb) and multiple system atrophy (msa) (dev. the pathogenesis of pd is unknown, although age and neurotoxins are associated risk factors. in recent decades, several causative genes have been identified, including three missense mutations, a30p (krger. 1998), e46k (zarranz. 2004) and a53 t (polymeropoulos. 1997) of -syn, which is strongly associated with early - onset pd (singleton. susceptibility studies suggest that contributing factors to pd include abnormal handling of misfolded proteins by the ubiquitin - proteasome system (ups) and autophagy - lysosomal pathway (alp), increased oxidative stress, and mitochondrial, lysosomal and other pathogenic dysfunctions (lesage and brice 2009). multiple independent studies have reported the association between gba mutations and parkinsonism with an increased frequency of heterozygous gba mutations in various cohorts of patients with parkinsonism (westbroek. furthermore, gba mutation carriers exhibit parkinsonian phenotypes and present a diffuse pattern of lb distribution in the cerebral cortex (do rosrio almeida 2012). the initial finding was that certain patients with gd exhibited parkinsonian symptoms and lb in the clinic, and additional reports were subsequently published (bembi. 2003 ; singleton. 2003 ; chartier - harlin. 2004 ; westbroek.. mutations in the gba gene were identified as from 4 to 28 % in cases with pd and lb disorders (goker - alpan. 2010 ; clark. 2005). in 2003, a group was assembled of 17 such individuals of various ethnicities, including ashkenazi jewish patients. the patients in this series had relatively mild gaucher manifestations with a mean age at diagnosis of 35 years (tayebi. their parkinsonian manifestations were similar to those noted in sporadic parkinson s disease, although many had an age of onset in their 40s, and most were younger than that for sporadic pd, although not all responded favorably to levodopa. these individuals exhibited asymmetric tremor, rigidity, akinesia and, at times, dementia, showing that cognitive changes had also occurred. autopsies were carried out in the brain and showed lb inclusions, appearing gcase - positive on immunostains, with a more diffuse distribution involving in the cerebral cortex, hippocampus and brainstem / limbic regions (nishioka. gba mutation carriers have diverse lb pathologies in brain regions and phenotypes compared to sporadic pd patients. it was noted that gd patients with parkinsonism frequently had relatives with parkinsonism who were heterozygous for gba mutations (goker - alpan. in immunological analyses of brain tissue from gd patients and gd carriers with parkinsonism, all the samples with gba mutations showed lb pathology (shachar. many other studies in different populations further support the link among gd, pd and lb disorders (clark. 2008 ; kalinderi. 2009 ; sidransky. 2009 ; mitsui. 2009 ; lesage. 2010 ; mao. 2010). a study of gba in 57 brain bank samples from subjects with pathologically confirmed pd demonstrated that 12 % carried a mutation, which was significantly higher than the mutation frequency even in the at - risk ashkenazi jewish population (lwin. family studies revealed that among relatives of gaucher probands, there was an increased number of individuals affected with parkinsonism (goker - alpan. importantly, several additional genetic studies in large patient cohorts demonstrated that patients with parkinsonism have an increased incidence of gba mutations. in 2009, sidransky. published a study that consisted of a collective analysis of 5691 patients with pd, complemented by 4898 controls, from 16 centers and across 12 countries. the full gba coding region was screened, and loss - of - function mutations were observed in 6.9 % of cases and 1.3 % of controls. among the ashkenazi jewish subset, higher mutation frequencies were seen : 19.3 % in cases and 4.1 % in controls (sidransky. subsequent studies indicated an increased incidence of pd in relatives of gd patients, many of whom were carriers of gba mutations (goker - alpan. 2006), making gba the most common known genetic risk factor for pd to date. furthermore, it is reported that non - motor symptoms (nmss) are more frequent in pd patients with heterozygous glucocerebrosidase mutations (pd - gba) (brockmann. the overall nms score was higher for pd - gba than sporadic pd patients, and pd - gba patients showed more severe cognitive dysfunction, apathy, depression and anxiety (mcneill. importantly, patients with gba - positive pd had significantly less precise memory compared to cases with gba - negative pd as well as gba - positive individuals without pd (zokaei. meanwhile, among gd patients and heterozygous carriers, hyposmia, cognitive dysfunction and parkinsonian motor signs are prevalent. hyposmia is the most common prodromal marker, 10 % in gd patients and gba carriers, suggesting that hyposmia develops before cognitive dysfunction or motor abnormalities (mcneill. hyposmia also occurs in lbd, in which olfactory dysfunction in lbd and pd is associated with lb deposition in the olfactory bulb, nucleus and cortex (williams. it proposes that hyposmia may be the most sensitive, but not a specific marker for identifying gd patients and carriers at greatest risk of developing pd. the mechanisms underlying the relation between gba mutations and the development of parkinson s disease remain elusive. however, recent studies provide some new perspectives. generally, in autosomal recessive forms of parkinson s disease, such as those involving park2, dj-1 and pink1, loss - of - function mutations are implicated, and these patients have an early onset of disease manifestation. by contrast, gain - of - function mutations, for example those in scna and lrrk2, are usually associated with autosomal dominant forms of parkinson s disease (hardy. the recognition of the link among gba mutants, gcase activity, snca and pd has made an important contribution to our thinking on the pathogenetic pathways in pd and dementia with lbs (lwin. support for gain - of - function mutations in gba is mainly from the following findings. most gba mutations are missense mutations, which result in a misfolded protein. in keeping with this is the finding that mutant gcase is present within a significant proportion of -syn inclusions in pd and gd brains (sardi. 2011, 2013), suggesting that this abnormal conformation could contribute to the development of parkinsonism by increasing -syn aggregation or directly interfering with the cellular autophagic - lysosomal mechanisms that mediate -syn degradation (cuervo. 2004). furthermore, mutant gcase can accumulate in the endoplasmic reticulum, overwhelming the ubiquitin - proteasome pathway, burdening the lysosomal system or causing impairment of autophagy. some gba mutations encountered in patients with parkinsonism are null mutations a finding in conflict with the gain - of - function hypothesis. in fact, carriers of null alleles might have an even higher risk of developing parkinsonism (neumann. the potential role of lipid homoeostasis in causing parkinson s disease is a topic of great interest. parkinsonism could arise as a consequence of gcase deficiency because of the loss of function of the enzyme. -syn can bind to the lipid raft - associated ganglioside gm1s (martinez. 2007 ; wei. 2009 ; yap. 2013), so disordered glucosylceramide (glccer) metabolism is postulated to affect proper trafficking of -syn to presynaptic membranes or to directly affect its fibrillization, leading to an accumulation of toxic -syn species. hence, lipid storage could cause changes in lipid homoeostasis, with subsequent alterations in synuclein processing (fortin. 2004 ; wei. 2009). in gcase ko mice markers of neurodegeneration, p62/sqstm1, ubiquitinated proteins and insoluble mitochondria were dysfunctional and fragmented, with impaired respiration and reduced respiratory chain complex activities. thus, a primary lysosomal defect causes accumulation of dysfunctional mitochondria as a result of impaired autophagy and dysfunctional proteasomal pathways (osellame. gcase enzyme activity was reduced in the substantia nigra and cerebellum in sporadic pd brains, and gcase deficiency was significantly observed in pd with gba brain areas. for the most part, gcase protein expression was lower in pd with gba and pd brains, as well also decreased in sh - sy5y cells overexpressing -syn or with pten - induced putative kinase 1 (pink1) deficiency (gegg. 2012). similar results were observed in fibroblasts from patients with gd and heterozygous mutation carriers with and without parkinson s disease compared with controls (mcneill. the clinical finding that most patients with gd never develop parkinson s disease, despite low gcase activity, argues against a solely loss - of - function mechanism. this theory is supported by the low frequency of parkinson s disease reported in the large gaucher cohort in the international collaborative gaucher group (icgg) gaucher registry (rosenbloom. thus, in most cases, the enzymatic deficiency can not predict parkinson s disease. -syn, a kind of presynaptic protein, is widely recognized for its role in pd. findings from recent studies have further suggested that -syn is involved in the pathogenesis of gba - associated parkinsonism. in the early stages of parkinson s disease, gcase deficits in sporadic parkinson s disease are related to the abnormal accumulation of -syn (murphy. recently, a selective interaction between -syn and gcase was determined (yap. 2011). the interaction occurred under lysosomal solution conditions (ph 5.5), and no significant interaction was noted at ph 7.4. residue level mapping showed that the interaction site was at the -syn c - terminal residues, 118137. immunoprecipitation and immunofluorescence studies verified this interaction in human tissue and neuronal cell culture, respectively. intriguingly, the n370s mutant form of gcase has a reduced affinity for -syn, so this binding at lysosomal ph might play an important role in facilitating -syn degradation or preventing aggregation. much of the processing of -syn occurs in the cytoplasm, where this interaction was unexpected, but it offers a possibility for lysosomal pathways in -syn degradation. when gba is mutated or absent, the beneficial role of the interaction in -syn processing is disrupted. these findings suggest that the -syn - gcase association is favored in the lysosome and that understanding this noncovalent interaction provides the groundwork to explore molecular mechanisms linking pd with mutant gba alleles. studied the association between -syn pathology and gcase from a different perspective (mazzulli. 2011). they performed a small hairpin rna (shrna)-mediated knockdown of gcase by lentiviral infection, which resulted in a 50 % reduction in gcase protein levels. reduced concentrations of endoglycosidase h - resistant gcase were also reported, ascribed to the depletion of the lysosomal form of the enzyme. gcase knockdown increased the steady - state levels of -syn 1.8-fold relative to controls, while the levels of tau, another disease - associated aggregation - prone protein, did not change. the same group then analyzed the dopaminergic neurons that were generated from induced pluripotent stem cells made from reprogrammed fibroblasts of a patient with gd. the results showed that these neurons also had an accumulation of -syn that resulted in neurotoxicity attributed to aggregation - dependent mechanisms. by working with a mouse model and human brain samples, they concluded that intracellular glccer levels control the formation of soluble toxic -syn oligomers and fibrils in cultured neurons, and mouse and human brain, leading to neurodegeneration. the promoted formation of -syn assemblies further contributes to a pathogenic cycle by inhibiting the lysosomal maturation and activity of normal gcase, resulting in additional glccer accumulation and elevated -syn oligomer formation. however, studies of brain samples indicate that aggregation of -syn is not related to gcase deficiency alone. proteins extracted from cerebral cortex samples from patients with synucleinopathies with and without gba mutations, as well as samples from control individuals and patients with gd, were studied by western blotting. patients with gba - associated parkinsonism showed aggregated oligomeric forms of -syn in the insoluble fraction, whereas only monomeric -syn was noted in patients with gba mutations without parkinsonism, including samples from patients with neuropathic gd (choi. 2011). recent evidence in saccharomyces cerevisiae and cell lines indicates that overexpression of -syn has the ability to block endoplasmic reticulum - golgi trafficking of proteins by inhibiting the formation of soluble n - ethylmaleimide - sensitive factor attachment protein receptor (snare) protein complexes (cooper. furthermore, mazzulli. used primary cortical neurons to demonstrate that overexpression of either wild - type or a53t - mutant -syn resulted in retention of gcase in the er, associated with reduced lysosomal gcase activity (mazzulli. 2011). they then confirmed this in vitro by studying gcase glycosylation patterns in pd and healthy control brain tissue. in addition, the same group analyzed human cortical material by gcase western blot and showed that normal variation of -syn protein levels modulates the lysosomal maturation and activity of gcase in vivo. taken together, these data suggest that elevated levels of -syn observed in pd and other synucleinopathies leads to decreased lysosomal activity of normal gcase (mazzulli. support for gain - of - function mutations in gba is mainly from the following findings. most gba mutations are missense mutations, which result in a misfolded protein. in keeping with this is the finding that mutant gcase is present within a significant proportion of -syn inclusions in pd and gd brains (sardi. 2011, 2013), suggesting that this abnormal conformation could contribute to the development of parkinsonism by increasing -syn aggregation or directly interfering with the cellular autophagic - lysosomal mechanisms that mediate -syn degradation (cuervo. 2004). furthermore, mutant gcase can accumulate in the endoplasmic reticulum, overwhelming the ubiquitin - proteasome pathway, burdening the lysosomal system or causing impairment of autophagy. some gba mutations encountered in patients with parkinsonism are null mutations a finding in conflict with the gain - of - function hypothesis. in fact, carriers of null alleles might have an even higher risk of developing parkinsonism (neumann. the potential role of lipid homoeostasis in causing parkinson s disease is a topic of great interest. parkinsonism could arise as a consequence of gcase deficiency because of the loss of function of the enzyme. -syn can bind to the lipid raft - associated ganglioside gm1s (martinez. 2007 ; wei. 2009 ; yap. 2013), so disordered glucosylceramide (glccer) metabolism is postulated to affect proper trafficking of -syn to presynaptic membranes or to directly affect its fibrillization, leading to an accumulation of toxic -syn species. hence, lipid storage could cause changes in lipid homoeostasis, with subsequent alterations in synuclein processing (fortin. 2009). in gcase ko mice markers of neurodegeneration, p62/sqstm1, ubiquitinated proteins and insoluble mitochondria were dysfunctional and fragmented, with impaired respiration and reduced respiratory chain complex activities. thus, a primary lysosomal defect causes accumulation of dysfunctional mitochondria as a result of impaired autophagy and dysfunctional proteasomal pathways (osellame. gcase enzyme activity was reduced in the substantia nigra and cerebellum in sporadic pd brains, and gcase deficiency was significantly observed in pd with gba brain areas. for the most part, gcase protein expression was lower in pd with gba and pd brains, as well also decreased in sh - sy5y cells overexpressing -syn or with pten - induced putative kinase 1 (pink1) deficiency (gegg. 2012). similar results were observed in fibroblasts from patients with gd and heterozygous mutation carriers with and without parkinson s disease compared with controls (mcneill. the clinical finding that most patients with gd never develop parkinson s disease, despite low gcase activity, argues against a solely loss - of - function mechanism. this theory is supported by the low frequency of parkinson s disease reported in the large gaucher cohort in the international collaborative gaucher group (icgg) gaucher registry (rosenbloom. thus, in most cases, the enzymatic deficiency can not predict parkinson s disease. -syn, a kind of presynaptic protein, is widely recognized for its role in pd. findings from recent studies have further suggested that -syn is involved in the pathogenesis of gba - associated parkinsonism. in the early stages of parkinson s disease, gcase deficits in sporadic parkinson s disease are related to the abnormal accumulation of -syn (murphy. recently, a selective interaction between -syn and gcase was determined (yap. 2011). the interaction occurred under lysosomal solution conditions (ph 5.5), and no significant interaction was noted at ph 7.4. residue level mapping showed that the interaction site was at the -syn c - terminal residues, 118137. immunoprecipitation and immunofluorescence studies verified this interaction in human tissue and neuronal cell culture, respectively. intriguingly, the n370s mutant form of gcase has a reduced affinity for -syn, so this binding at lysosomal ph might play an important role in facilitating -syn degradation or preventing aggregation. much of the processing of -syn occurs in the cytoplasm, where this interaction was unexpected, but it offers a possibility for lysosomal pathways in -syn degradation. when gba is mutated or absent, the beneficial role of the interaction in -syn processing is disrupted. these findings suggest that the -syn - gcase association is favored in the lysosome and that understanding this noncovalent interaction provides the groundwork to explore molecular mechanisms linking pd with mutant gba alleles. studied the association between -syn pathology and gcase from a different perspective (mazzulli. 2011). they performed a small hairpin rna (shrna)-mediated knockdown of gcase by lentiviral infection, which resulted in a 50 % reduction in gcase protein levels. reduced concentrations of endoglycosidase h - resistant gcase were also reported, ascribed to the depletion of the lysosomal form of the enzyme. gcase knockdown increased the steady - state levels of -syn 1.8-fold relative to controls, while the levels of tau, another disease - associated aggregation - prone protein, did not change. the same group then analyzed the dopaminergic neurons that were generated from induced pluripotent stem cells made from reprogrammed fibroblasts of a patient with gd. the results showed that these neurons also had an accumulation of -syn that resulted in neurotoxicity attributed to aggregation - dependent mechanisms. by working with a mouse model and human brain samples, they concluded that intracellular glccer levels control the formation of soluble toxic -syn oligomers and fibrils in cultured neurons, and mouse and human brain, leading to neurodegeneration. the promoted formation of -syn assemblies further contributes to a pathogenic cycle by inhibiting the lysosomal maturation and activity of normal gcase, resulting in additional glccer accumulation and elevated -syn oligomer formation. however, studies of brain samples indicate that aggregation of -syn is not related to gcase deficiency alone. proteins extracted from cerebral cortex samples from patients with synucleinopathies with and without gba mutations, as well as samples from control individuals and patients with gd, were studied by western blotting. patients with gba - associated parkinsonism showed aggregated oligomeric forms of -syn in the insoluble fraction, whereas only monomeric -syn was noted in patients with gba mutations without parkinsonism, including samples from patients with neuropathic gd (choi. 2011). recent evidence in saccharomyces cerevisiae and cell lines indicates that overexpression of -syn has the ability to block endoplasmic reticulum - golgi trafficking of proteins by inhibiting the formation of soluble n - ethylmaleimide - sensitive factor attachment protein receptor (snare) protein complexes (cooper. furthermore, mazzulli. used primary cortical neurons to demonstrate that overexpression of either wild - type or a53t - mutant -syn resulted in retention of gcase in the er, associated with reduced lysosomal gcase activity (mazzulli. 2011). they then confirmed this in vitro by studying gcase glycosylation patterns in pd and healthy control brain tissue. in addition, the same group analyzed human cortical material by gcase western blot and showed that normal variation of -syn protein levels modulates the lysosomal maturation and activity of gcase in vivo. taken together, these data suggest that elevated levels of -syn observed in pd and other synucleinopathies leads to decreased lysosomal activity of normal gcase (mazzulli. the proposed gain - of - function or loss - of - function mechanisms do not perfectly explain the association between pd and gd, and there are some clinical exceptions for each of them. therefore, the focus should be on the altered function of -syn in the observed association instead of a single gain or loss of function. a newly identified interaction between -syn and gcase was reported that might influence cellular levels of -syn by either promoting protein degradation and/or preventing aggregation (sybertz and krainc 2014 ; yap. the authors also demonstrated that membrane - bound -syn interacted with gcase and that this complex formation inhibited enzyme function. the interaction of -syn and gcase in lysosomes may be beneficial to the degradation of -syn, while intracellular glccer levels control the formation of soluble toxic -syn oligomers and fibrils (mazzulli. in other words, the interactions between -syn and gcase and between -syn and glccer have opposite effects on the aggregation of -syn. some gba mutations result in misfolded gcase, which has no activity but can still interact with -syn in lysosomes and contribute to the degradation. thus, the aggregation of -syn caused by glccer is compromised, which may explain why gd patients with low gcase activity will not develop parkinsonism. when gba mutations affect the interaction site, like n370s, the beneficial role of the interaction in -syn processing is disrupted, and the balance between aggregation and degradation is broken. this may be why carriers of null alleles might have an even higher risk of developing parkinsonism (neumann., if the aggregation of -syn can not be cleared, it will further inhibit the lysosomal maturation and gcase activity, resulting in additional glccer accumulation and elevated -syn. recent data show that increasing gcase activity with adeno - associated viral vector (aav) delivery of the enzyme into the brain of a gd mouse model can reduce the accumulation of snca, tau and ubiquitin (sardi. 2013). it suggested that increasing the glycosidase activity can modulate -syn processing and may modulate the progression of -synucleinopathies. in addition, neuronal glucosylceramide (glccer) accumulates to a certain threshold ; a series of second events is triggered, which includes neuroinflammation and neurodegeneration, then subsequently causes neuronal death (farfel - becker. 2014). hence, increasing the gcase activity in the cns represents a potential therapeutic strategy for gba - related and non - gba - associated synucleinopathies, including pd (schapira and gegg 2013). since a reduction of glucosylceramidase protein levels and activity occurs in the brain of gd and pd patients with gba mutation carriers, gcaes is a potential treatment target for gd therapy. ambroxol hydrochloride, a small molecule, reduces alpha - synuclein levels in overexpressing neuroblastoma cells and markers of oxidative and endoplasmic reticulum stress in cells bearing gcase mutations. ambroxol treatment results in a significant elevation of glucosylceramidase protein and activity levels in gd and pd with gba mutations by activating the coordinated lysosomal expression and regulation network (mcneill. in addition, lysosomal activity of gc is tightly linked to expression of its trafficking receptor, the lysosomal integral membrane protein type-2 (limp-2), which acts as a chaperone helping to traffic glucosylceramidase from the endoplasmic reticulum to the lysosome ; therefore, manipulating limp-2 expression to increase lysosomal gc activity is also a promising strategy for the treatment of synucleinopathies and gba mutation carriers. heterologous expression of limp-2 accelerated clearance of overexpressed -synuclein and promoted autophagic / lysosomal function, possibly by increasing lysosomal gc activity (rothaug. additionally, the receptor - interacting protein kinases (ripks), a class of serine / threonine protein kinases, are directly involved in the pathway of pathological events in severe forms of gd. the significant extension of lifespan and improvements of motor coordination in ripk3 knockout mice support the notion that ripk3 is not only a key activator of necrotic cell death, but also the ripk3 pathway might be a molecular target for therapeutic intervention in gd (vitner. further studies using techniques in cell biology, neuropathology and genetics are needed to better reveal the mechanisms that contribute to gba - associated parkinsonism. the role of -syn and gcase will continue to be a source of considerable interest in the field. elucidating the factors underlying this association is necessary to improve genetic counseling for people who carry mutations in this gene. moreover, a better understanding of the role of gcase in the development of parkinsonism will facilitate the development of new therapeutic strategies for gba - associated parkinsonism. | gaucher disease is associated with parkinson s disease (pd) by mutations in glucocerebrosidase (gcase). the gene encoding gcase, glucosidase beta acid (gba), is an important risk factor for pd. findings from large studies have shown that patients with pd have an increased frequency of mutations in gba and that gba mutation carriers exhibit diverse parkinsonian phenotypes and lewy body pathology. although the mechanism for this association remains elusive, some hypotheses have been proposed to explain it, including gain of function caused by gba mutations, which increases -synuclein (-syn) aggregation, loss of function due to lysosomal enzyme deficiency, which affects -syn clearance, and even a bidirectional feedback loop, but each of these hypotheses has its limitations. it is also worth noting that many findings have implicated the interaction between -syn and gcase, indicating the essential role of the interaction in the pathogenesis of gba - associated parkinsonism. therefore, the current review focuses on -syn and gcase, and it provides some new thoughts that may be helpful for understanding the -syn - gcase interaction and unraveling the exact mechanism underlying gba - associated parkinsonism. |
the maintenance of gut immune homeostasis depends on mechanisms regulating the interaction between the intestinal microbiota and host epithelial, stromal, and immune cells (hooper. the intestinal epithelium forms a physical and biochemical barrier between luminal bacteria and mucosal immune cells. it actively influences the intestinal microbiota by secreting anti - microbial factors and modulates mucosal immune responses via the production of immunoregulatory proteins (hooper., 2012, paneth cells, specialized secretory intestinal epithelial cells found in small intestinal crypts, release peptides with anti - microbial activity that are believed to regulate the gut microbiota (kaser., 2010, ouellette, 2010). deregulation of intestinal immune homeostasis results in chronic inflammatory bowel diseases, including crohn s disease (cd) and ulcerative colitis (uc). genetic, microbial, and environmental factors are thought to contribute to the pathogenesis of ibd ; however, the mechanisms responsible for the initiation and chronicity of intestinal inflammation remain poorly understood (blumberg and powrie, 2012, kaser., 2010). tumor necrosis factor (tnf) plays a critical role in intestinal inflammation as illustrated by the clinical efficacy of anti - tnf therapies in cd and uc (peyrin - biroulet, 2010). however, the tnf - dependent molecular and cellular mechanisms that contribute to the pathogenesis of ibd remain elusive. tnf signals primarily via tnf receptor 1 (tnfr1) to activate pro - survival and proinflammatory nf-b and mitogen - activated protein kinase signaling or, when pro - survival responses are compromised, to induce cell death by fadd - caspase-8-dependent apoptosis or ripk3-mixed lineage kinase domain - like (mlkl)-mediated necroptosis (pasparakis and vandenabeele, 2015). ripk1 is a key regulator of tnfr1 signaling that induces prosurvival and proinflammatory responses via kinase - independent scaffolding functions but also apoptosis or necroptosis via its kinase activity (pasparakis and vandenabeele, 2015). recent studies revealed the important role of kinase - independent ripk1 functions in intestinal epithelial homeostasis (dannappel., 2014, dillon., 2014, rickard., 2014, takahashi., 2014), the nf-b protein family consists of rela, c - rel, relb, p50, and p52, which form hetero- and homodimers that control the transcription of nf-b target genes by binding to consensus dna sites in cis - regulatory regions (oeckinghaus and ghosh, 2009). rela, c - rel, and relb have transcription transactivation domains, and hence nf-b dimers containing these proteins are capable of activating gene expression (oeckinghaus and ghosh, 2009). p50 and p52 do not contain transactivation domains, and therefore p50 and p52 homodimers do not activate but rather suppress gene transcription. nf-b dimers are kept inactive in resting cells by binding to inhibitor of nf-b (ib) proteins. the ib kinase (ikk) complex, consisting of the nemo (also named ikk) regulatory subunit and the ikk1 (also named ikk) and ikk2 (also named ikk) kinases, activates nf-b by phosphorylating ib proteins, triggering their ubiquitin - dependent degradation and allowing the nuclear accumulation of nf-b dimers and the transcription of target genes (karin and greten, 2005, oeckinghaus and ghosh, 2009). mice with iec - specific nemo deficiency develop spontaneous colitis that depends on myd88 and tnfr1 signaling (nenci., 2007). interestingly, human patients with ectodermal dysplasia with immunodeficiency (eda - id) caused by hypomorphic nemo mutations often suffer from colitis that is not resolved by hematopoietic stem cell transplantation (fish., 2008, permaul., 2009), suggesting that nemo deficiency in stromal cells also causes colon inflammation in humans. these results suggested that nemo - mediated nf-b activation in the intestinal epithelium is important for the maintenance of intestinal homeostasis in both mice and humans. however, mice lacking rela in iecs do not develop spontaneous intestinal inflammation although they are highly sensitive to dextran sulfate sodium (dss)-induced colitis (steinbrecher., 2008), questioning to which extent inhibition of nf-b activation accounts for the disruption of intestinal epithelial homeostasis and the spontaneous development of colitis in mice with iec - specific nemo deficiency. here we show that nemo exerts nf-b - dependent and -independent functions that control intestinal homeostasis and inflammation by inhibiting ripk1 kinase activity - dependent death of intestinal epithelial cells. these results revealed an important role of ripk1 kinase activity in intestinal homeostasis, suggesting that ripk1 kinase inhibitors could be effective for the treatment of gut inflammation in patients with nemo mutations and might also prove beneficial in the therapy of ibd. mice lacking nemo specifically in iecs (ikbkg or ikbkg villin - cre, hereafter referred to as nemo) spontaneously developed chronic colitis, manifesting with diarrhea, thickening of the colonic wall, epithelial erosion, and ulcer formation, increased infiltration of immune cells in the mucosa and submucosa, and increased mrna expression of pro - inflammatory cytokines and chemokines such as tnf, il1b, cxcl1, ccl2, and ccl5 (figures 1a1d). increased numbers of apoptotic iecs, identified by staining for cleaved caspase-3, we showed previously that systemic tnfr1 deficiency inhibited colitis development in nemo mice (nenci., 2007). to address whether iec - intrinsic tnfr1 signaling triggered colitis in nemo mice, we crossed them with mice carrying loxp - flanked tnfr1 alleles (tnfrsf1a) (van hauwermeiren., 2013) iec - specific knockout of tnfr1 prevented colonic epithelial cell death and the development of colitis in nemo mice as shown by histological and cytokine expression analysis (figures 1e1h). therefore, epithelial - intrinsic tnfr1 signaling induces colonocyte death and colitis in nemo mice. the death of nemo - deficient iecs was proposed to trigger colitis in nemo mice by disrupting the intestinal barrier allowing luminal bacteria to invade the mucosa and induce tlr - mediated inflammation (nenci., 2007, pasparakis, 2009). indeed, nemo mice raised under germ - free conditions did not develop colon inflammation and showed reduced numbers of apoptotic iecs (figures 1i1l, s1). conventionalization of germ - free nemo mice by co - housing with spf mice resulted in the development of colitis within 24 weeks (figures 1i1l, s1). the ileum of nemo mice did not show epithelial erosion but had mildly increased immune cell infiltration although mrna levels of tnf and il1b were not elevated (figures 2a2d, figure s2a). increased numbers of apoptotic iecs were almost exclusively detected in the crypt area and were rarely found in the villus. the number of paneth cells, identified by their characteristic granule - filled morphology as well as by immunostaining for lysozyme was strongly reduced in nemo mice (figures 2a and 2e). in addition, nemo mice showed strongly reduced mrna expression of anti - microbial factors produced specifically by paneth cells including lyz1, defa - rs1, and ang4 (figure 2f). to assess whether the absence of paneth cells in nemo mice reflected developmental or differentiation defects or whether it was caused by cell death, we employed mice allowing tamoxifen - inducible ablation of nemo in iecs (ikbkg or ikbkg villin - creert2, hereafter referred to as nemo mice). nemo and nemo littermate controls that did not carry the villin - creer transgene were injected intraperitoneally with 1 mg tamoxifen on 5 consecutive days and were sacrificed on day 5 or day 8 for analysis. this protocol resulted in efficient nemo ablation and activation of caspase-3 in iecs (figure s2i). immunostaining of ileal sections from nemo mice sacrificed on day 5 did not reveal considerable tissue damage and inflammation or paneth cell loss, although small numbers of apoptotic iecs were detected mainly in the crypt base (figures s2b s2d). however, 8 days after the first tamoxifen injection nemo mice showed moderate tissue damage and immune cell infiltration, as well as strongly reduced numbers of paneth cells and diminished expression of paneth cell markers, accompanied by an increased number of apoptotic iecs in small intestinal crypts (figures 2g2k). considering that paneth cells are long lived with an estimated turnover time of about 60 days (ireland., 2005), the finding that inducible nemo deficiency resulted in paneth cell loss within 8 days suggests that nemo - deficient paneth cells died, most likely by apoptosis as indicated by the presence of cleaved caspase-3-positive cells in intestinal crypts. inflammatory cytokines and chemokines were not upregulated in the ileum of nemo mice (figure 2l), showing that the increased number of apoptotic iecs and the loss of paneth cells did not trigger inflammation. tamoxifen - inducible nemo knockout caused increased iec apoptosis, pronounced tissue damage, immune cell infiltration and strongly increased inflammatory cytokine and chemokine expression in the colon (figures s2e s2h). our results presented above showed that epithelial intrinsic tnfr1 signaling induces the death of nemo - deficient colonocytes triggering microbiota - driven colitis in nemo mice. to assess whether similar mechanisms contribute to paneth cell loss in nemo mice, we first analyzed ileal tissue from germ - free animals. paneth cell numbers and the expression of paneth cell - derived antimicrobial factors was strongly reduced in germ - free nemo mice compared to nemo littermates (figures 3a3c). moreover, germ free nemo mice showed iec apoptosis in ileal crypts and tissue damage, albeit to a reduced extent compared to spf mice (compare figures 3d and 3e and 2a2f). we next asked whether tnfr1 signaling also triggered iec death and paneth cell loss in the small intestine of nemo mice. examination of ileal sections from nemo tnfr1 mice revealed that iec - specific tnfr1 deficiency did not diminish iec apoptosis, tissue damage, and loss of paneth cells (figures s3a s3e). to address whether fas or trailr2, presumably acting in a redundant fashion with tnfr1, could be involved in triggering the death of nemo - deficient paneth cells, we generated nemo mice with simultaneous iec - specific ablation of tnfr1, fas, and trailr2 (ikbkg or ikbkg tnfrsf1a fas tnfrsf10b villin - cre, hereafter referred to as nemo dr) (figures s3f s3h). even the combined loss of tnfr1, fas and trailr2 could not prevent paneth cell loss and tissue damage in ilea of nemo dr animals, although it mildly reduced the number of apoptotic iecs (figures 3f3j, compare with figures 2a2f). thus, paneth cell loss in nemo mice occurred independently of the microbiota and death receptor signaling. most dying iecs in the intestine of nemo mice stained positive for cleaved caspase-3 suggesting that they die primarily by apoptosis. we therefore sought to address whether iec apoptosis triggers the intestinal pathology of nemo mice by crossing them with mice carrying loxp - flanked alleles of fadd (fadd), an adaptor protein that is essential for caspase-8-dependent apoptosis. nemo fadd mice developed colitis and failed to thrive (data not shown), showing that fadd ablation did not prevent colon inflammation. as mice lacking fadd in iecs develop spontaneous colitis due to ripk3-dependent epithelial cell necroptosis (welz., 2011), we reasoned that necroptosis of iecs lacking both nemo and fadd could trigger colitis in nemo fadd mice. indeed, nemo fadd ripk3 mice developed normally and did not show macroscopic signs of colitis. histological analysis revealed a normal colonic mucosa without signs of epithelial erosion, tissue damage, and inflammatory cell infiltration (figures 4a4c), while proinflammatory genes were not upregulated in the colons of nemo fadd ripk3 mice (figure 4e). moreover, nemo fadd ripk3 mice did not show paneth cell loss in the ileum (figures 4f4k). a few scattered cells staining for cleaved caspase-3 were observed in the colon and ileum of nemo fadd ripk3 mice (figures 4a, 4d, and 4f), but it is not clear whether these correspond to cells that escaped fadd deletion or cells undergoing fadd - independent apoptosis. these results showed that inhibition of apoptosis and necroptosis by combined ablation of fadd and ripk3 fully protected nemo mice from paneth cell loss and the development of colitis. because ripk3 deficiency in the context of epithelial fadd knockout fully prevented intestinal pathology in nemo mice, we wondered whether ripk3 might have a role independently of fadd. we therefore generated nemo ripk3 mice and found that ripk3 deficiency ameliorated the severity of colitis, with about 70% of the examined nemo ripk3 animals (13 out of 17 mice analyzed at the age of 26 months) showing either overall mild inflammation affecting the entire colon or with only focal appearance of inflammatory lesions (figures 5a and 5b). the remaining 30% of nemo ripk3 mice developed severe pan - colitis that was histologically indistinguishable from the colitis observed in nemo mice (figures 5a and 5b). analysis of cytokine and chemokine expression confirmed that ripk3 deficiency considerably inhibited inflammation in most nemo ripk3 animals (figure 5d, s4a). this variability was observed also within co - housed littermates suggesting that maternal or housing effects on the microbiota could not explain the incomplete penetrance of the protective effect provided by ripk3 deficiency. the mechanisms responsible for the variability of colitis severity in nemo ripk3 mice remain elusive at present and might be related to stochastic events precipitating disease in individual animals. examination of ileal tissue from nemo ripk3 mice revealed reduced paneth cell numbers, decreased expression of paneth cell markers and elevated numbers of apoptotic iecs, similarly to nemo mice (figures 5e5h and s4). therefore, colitis development partly depends on ripk3 while loss of paneth cells occurs independently of ripk3. it remains unclear whether ripk3 modulates colitis by contributing to iec death or by regulating inflammation in a cell - death independent manner. to assess whether ripk1 kinase activity contributes to iec death and intestinal pathology in nemo mice, we crossed them with knockin mice expressing kinase inactive mutant ripk1d138n (polykratis., 2014). nemo ripk1 mice showed a normal colonic mucosa without signs of inflammation, with only a few scattered apoptotic colonocytes detected (figures 6a6d). moreover, lack of ripk1 kinase activity also very strongly inhibited iec apoptosis and loss of paneth cells in the ileum of nemo ripk1 mice (figures 6e6i). to obtain insights on the mechanisms triggering the death of nemo - deficient iecs, we assessed the formation of the fadd / caspase-8 apoptosis - inducing signaling complex. immunoprecipitation of fadd showed that caspase-8 and ripk1 strongly interacted with fadd in colon extracts from nemo but not nemo or nemo ripk1 mice (figure 6j). these findings indicate that nemo deficiency triggers the ripk1 kinase activity - dependent formation of a ripk1/fadd / caspase-8 signaling complex that induces apoptosis in iecs. collectively, these findings show that ripk1 kinase activity - mediated death of iecs causes paneth cell loss and colitis development in nemo mice. to address whether epithelial nemo deficiency causes intestinal pathology by inhibiting nf-b activation, we sought to directly inhibit nf-b by generating mice with iec - specific knockout of nf-b subunits. as reported earlier mice with iec - specific rela deficiency (rela villin - cre, hereafter referred to as rela) did not develop spontaneous colitis (figures s5a s5d). however, rela mice showed increased iec apoptosis and reduced paneth cell numbers in ileal crypts, as well as reduced expression of paneth - cell - specific genes (figures 7a7e). rela ripk1 mice did not exhibit iec death and loss of paneth cells (figures 7a7e), showing that ripk1 kinase activity induces paneth cell death also in rela mice. the absence of spontaneous colitis in rela mice could be due to compensation of rela function by other nf-b subunits. to address potential redundancies among nf-b factors, we generated mice lacking all three rel proteins capable to activate gene transcription (namely rela, relb, and c - rel) specifically in iecs (rela relb c - rel villin - cre, hereafter referred to as nf-b mice) (figure s5f). combined lack of rela, c - rel, and relb as well as nemo deficiency blunted tnf - induced expression of nf-b - dependent genes demonstrating efficient inhibition of nf-b responses (figure s5h). in contrast to nemo, nf-b animals did not develop spontaneous colitis although small numbers of cleaved caspase-3 positive epithelial cells and mild inflammation were detected in the colon of some of these mice (figures 7f7i). thus, even complete inhibition of nf-b activity in the intestinal epithelium was not sufficient to trigger spontaneous colitis development, suggesting that nemo prevents colitis via nf-b - independent functions. similarly to rela, nf-b mice showed elevated numbers of apoptotic iecs and paneth cell loss in ileal crypts (figures 7j7n). however, paneth cell loss in nf-b or rela mice was not as severe as in nemo mice suggesting that inhibition of nf-b activation can only partly explain the loss of paneth cells in nemo mice. these results suggest that nf-b activity inhibits paneth cell apoptosis in the ileum, but nf-b - independent nemo functions prevent iec death and chronic inflammation in the colon. to address whether the tnf - dependent embryonic lethality of rela mice also depends on ripk1 kinase activity, we crossed them to ripk1 animals. rela ripk1 mice were born, albeit at somewhat reduced numbers compared to the expected mendelian ratio, but died during the first weeks of life (figure s6) most likely due to infections as previously shown for rela tnfr1 mice (alcamo., 2001). moreover, we found that nemo - deficient mice were also born, though at reduced ratio, in the ripk1 genetic background (figure s6). therefore, the embryonic lethality evoked by nemo or rela deficiency is caused, at least in part, by ripk1 kinase activity - dependent tnf - induced death of cells in the fetal liver, suggesting that nf-b activity is essential during embryogenesis to restrain ripk1-dependent cell death. deregulation of intestinal epithelial responses to the microbiota and the cytokine microenvironment of the gut are believed to contribute to the pathogenesis of inflammatory bowel diseases (blumberg and powrie, 2012, hooper. the nf-b pathway controls cellular responses to microbes and cytokines and a number of studies suggested that nf-b activation in iecs controls intestinal immune homeostasis (eckmann., 2008, particularly the finding that nemo mice develop spontaneous colitis suggested that epithelial nf-b signaling is essential to prevent colon inflammation (nenci., 2007). nf-b subunit redundancy and the embryonic lethality of rela - deficient mice made it difficult to address the functional role of nf-b signaling in the gut. to overcome these limitations, we employed conditional targeting of all nf-b subunits capable of transcriptional activation, namely rela, c - rel, and relb, to generate mice lacking nf-b activity in the intestinal epithelium. our studies revealed that even complete inhibition of nf-b in iecs did not cause spontaneous colitis as seen in the nemo mice, demonstrating that nf-b activity in iecs is not essential to prevent colon inflammation under steady - state conditions. in contrast, nf-b inhibition caused iec death and paneth cell loss in the small intestine similarly to nemo knockout. nemo - mediated nf-b activation inhibits the death of iecs and loss of paneth cells in the small intestine, while nf-b - independent nemo functions prevent iec death and inflammation in the colon. the potentially differential role of apoptosis and necroptosis in regulating inflammation has been the subject of debate. apoptosis is believed to be less inflammatory than necroptosis due to the limited release of damps by apoptotic cells (pasparakis and vandenabeele, 2015), although the consequences of these distinct types of regulated cell death in the intestinal epithelium remain poorly understood. most dying iecs in the nemo mice stained for cleaved caspase-3, suggesting that they died by apoptosis. due to the absence of a reliable marker for the identification of necroptotic cells in mouse tissues, we were not able to assess and quantify the occurrence of necroptosis in these mice. our efforts to genetically dissect the contribution of apoptosis and necroptosis of iecs in nemo mice also did not lead to unambiguous results. we attempted to specifically address the contribution of iec apoptosis by generating mice lacking both nemo and fadd in the intestinal epithelium and found that these mice developed intestinal inflammation. iec death, paneth cell loss, and colitis development in nemo mice were fully prevented by fadd epithelial knockout combined with systemic ripk3 deficiency, showing that inhibition of both apoptotic and necroptotic death of iecs protects these mice from intestinal pathology. however, since fadd epithelial deficiency caused iec necroptosis and colitis in mice (welz., 2011), a likely interpretation of these findings is that fadd knockout might prevent apoptosis of nemo - deficient iecs, but at the same time renders them susceptible to ripk3-dependent necroptosis. deficiency alone did not prevent paneth cell loss but partially ameliorated colitis severity in nemo mice. these results show that necroptosis is not involved in iec death in the small intestine but indicate that it could be partly implicated in the death of colonocytes and colitis development in these mice. however, ripk3 has been suggested to also mediate apoptosis as well as cell - death - independent functions relevant for inflammation. a recent study reported that ripk3 deficiency exacerbated dss - induced colitis, which was attributed to a function of ripk3 in promoting the expression of cytokines required for efficient injury repair in dendritic cells (moriwaki., 2014). this proposed anti - inflammatory function of ripk3 opposes its predominantly pathogenic role in the nemo mice and is therefore unlikely to contribute to the amelioration of colitis in nemo ripk3 mice. furthermore, ripk3 has been suggested to regulate inflammasome activation and il-1 release in a necroptosis - independent manner (kang., 2013, therefore, because of the complex and as - yet incompletely understood functions of ripk3 in cell death and inflammation, at this stage it is unclear whether ripk3 deficiency ameliorates colitis in nemo mice by inhibiting necroptosis or apoptosis or other proinflammatory ripk3 functions. further experiments will be required to dissect the potential role of necroptosis in the development of colitis in nemo mice. our results provide in vivo experimental evidence that ripk1 kinase activity - dependent death of nemo - deficient epithelial cells triggers paneth cell loss in the small intestine and severe chronic inflammation in the colon. in contrast, iec death and loss of paneth cells occurs in the combined absence of tnfr1, fas and trailr2, and does not require the presence of the microbiota, although germ - free conditions ameliorated the pathology indicating that intestinal bacteria contribute to the severity of the ileal phenotype. trif - dependent tlr signaling, but also type i and type ii interferon receptors have been shown to induce ripk1-dependent cell death, suggesting that these receptors might contribute to the death of nemo - deficient enterocytes. the molecular mechanisms by which nemo and nf-b signaling prevent ripk1-mediated iec death remain unclear. earlier in vitro studies in cell lines suggested that nemo interacts with ripk1 via its ubiquitin - binding domain and prevents the engagement of fadd / caspase-8 to trigger apoptosis (legarda - addison., 2009) or, when caspase 8 is inhibited, necroptosis (odonnell., 2012). however, in these in vitro studies ripk1 kinase activity was suggested to be required for necroptosis but not for apoptosis of nemo deficient cells (odonnell., 2012), while our results suggest that ripk1 causes intestinal pathology primarily by inducing iec apoptosis. a recent study suggested that ikk1 and ikk2 prevent tnf - induced cell death by directly phosphorylating ripk1 and inhibiting ripk1-induced death signaling independently of nf-b, and proposed that loss of ikk1/2 or nemo causes ripk1-dependent death while nf-b inhibition causes ripk1-independent cell death downstream of tnfr1 signaling (dondelinger. however, our results showing that ripk1 kinase activity mediates death of nemo- or p65-deficient iecs but also embryonic lethality of nemo- or p65-deficient mice provide in vivo experimental evidence that nf-b signaling also controls ripk1-mediated cell death. these results suggest that ikk / nf-b signaling acts at multiple levels both by directly interacting with upstream components of the cell death machinery such as ripk1, but also by inducing the expression of pro - survival genes. nemo could directly bind ripk1 via its ubiquitin binding domain and this interaction might be important to prevent the formation of the ripk1-containing signaling complex. indeed, our immunoprecipitation experiments suggested that nemo deficiency triggers the formation of a ripk1/fadd / caspase-8 apoptosis - inducing signaling complex. further studies will be required to dissect the ikk- and nf-b - dependent mechanisms regulating ripk1-induced cell death. loss of paneth cells is frequently observed in cd and might be functionally implicated in the development of intestinal inflammation in these patients, presumably by inducing dysbiosis (blumberg and powrie, 2012, kaser., 2010). our results showing that rela mice exhibit extensive loss of paneth cells but do not develop spontaneous intestinal inflammation suggest that death of paneth cells is not sufficient to disrupt homeostasis and cause ileitis or colitis even in the presence of an underlying nf-b defect in the intestinal epithelium. however, although paneth cell loss is not sufficient by itself to cause the disease, it might contribute to the development of colitis in nemo mice. human patients with hypomorphic nemo mutations develop ectodermal dysplasia accompanied with severe immunodeficiency (eda - id) and about 25% of these patients suffer from inflammatory colitis (hanson., 2008, hematopoietic stem cell transplantation (hsct) has been used for the treatment of immunodeficiency in eda - id patients (fish., 2009, although hsct could successfully restore immune function, it did not improve but rather worsened colitis (fish. 2008), suggesting that stromal nemo deficiency causes colitis in human eda - id patients similarly to our mouse model with epithelial specific nemo knockout. tnf neutralizing antibodies were effective in treating colitis in eda - id (mizukami., 2012), showing that similarly to nemo mice, tnf causes colitis in the human patients. however, considering the impaired immune function of nemo eda - id patients, additional treatment with anti - tnf increases the risk of serious bacterial infections. our results that inhibition of ripk1 kinase activity prevented the development of intestinal pathology in nemo mice suggest that ripk1 kinase inhibitors could be highly effective for the treatment of gastrointestinal complications in human patients with eda - id caused by nemo mutations, in particular after successful restoration of immune function by hsct. because knockin mice expressing kinase inactive ripk1 do not show any abnormalities, ripk1 kinase inhibitors are expected to be well tolerated and should therefore be superior to anti - tnf treatment for these patients. intestinal epithelial cell death is commonly observed in patients with inflammatory bowel diseases, including cd and uc (seidelin and nielsen, 2009, souza., 2005). although mutations in nemo have not been associated with ibd, considering that anti - tnf therapy is highly effective in the treatment of cd and uc and reduces epithelial cell death (zeissig., 2004), it is tempting to speculate that ripk1 kinase activity might contribute to the pathogenic role of tnf in human ibd patients by triggering intestinal epithelial cell death. in the absence of evidence that ripk1-induced epithelial cell death occurs and is functionally relevant for the pathogenesis of ibd, this remains an interesting hypothesis that awaits experimental validation. mice were maintained at the spf animal facilities of the institute for genetics and the cecad research center, university of cologne, under a 12 hr light cycle and were given a regular chow diet (harlan, diet no. germ - free mice were produced at the gnotobiotic facility of the university of ulm. all animal procedures were conducted in accordance with european, national, and institutional guidelines, and protocols were approved by local government authorities (landesamt fr natur, umwelt und verbraucherschutz nordrhein - westfalen). animals requiring medical attention were provided with appropriate care and excluded from the experiments described. iecs were isolated by subsequent incubation of intestinal tissue in 1 mm dithiothreitol (dtt) and 1.5 mm edta solutions as described previously (dannappel., 2014). cell lysates were separated on sds - page and transferred to pvdf membranes (ipvh00010, millipore). primary antibodies used for immunoblot analysis : rela c-20 (sc-372), relb c-19 (sc-226), and c - rel (sc-71), -actin 1 - 19 (sc-161) and hdac1 h-51 (sc-7872) from santa cruz, tnfr1 (d317k) ; caspase 3 (9662), cleaved caspase 3 (9661) from cell signaling ; ripk1 (610459) from bd ; ripk3 (adi-905 - 242 - 100) from enzo life sciences ; fadd (1f7) 05 - 486 from upstate ; cre 69050 - 3 from novagen ; caspase-8 (alx-804 - 447) from alexis ; and nemo (homemade rabbit polyclonal serum) and -tubulin (t6074) from sigma. secondary hrp - coupled antibodies (ge healthcare, jackson immuno research) and chemiluminescent detection substrate (ge healthcare and thermo scientific) were used. for immunoprecipitation, colon tissue was lysed in ip buffer and fadd was precipitated with goat anti - fadd (m19) (sc-6036) antibody from santa cruz linked to protein g dynabeads (life technologies). intestinal tissues were fixed in 4% paraformaldehyde, embedded in paraffin, and cut in 3 m sections. for histopathological analysis, hematoxylin and eosin staining paraffin sections were rehydrated and heat - induced antigen retrieval was performed in citrate buffer at ph 6.0. primary antibodies for ihc were anti - cleaved caspase 3 asp175 (9661, cell signaling), anti - human lysozyme (f0372, dako) and rela c-20 (sc-372), santa cruz. stainings were visualized with abc kit vectastain elite (vector laboratories) or streptavidin - hrp (millipore) and dab substrate (dako and vector laboratories). small intestinal organoids were isolated and cultured as described previously (dannappel., 2014). after passaging, cultures were grown for 2 to 3 days and stimulated with 5 ng / ml recombinant murine tnf. at indicated time points, statistical analysis was performed with prism6, graphpad applying student s t tests with welch s correction in case of unequal variance. a.p. generated the ripk1 mice and performed and analyzed the nemo ripk1 crosses. | summaryintestinal epithelial cells (iecs) regulate gut immune homeostasis, and impaired epithelial responses are implicated in the pathogenesis of inflammatory bowel diseases (ibd). iec - specific ablation of nuclear factor b (nf-b) essential modulator (nemo) caused paneth cell apoptosis and impaired antimicrobial factor expression in the ileum, as well as colonocyte apoptosis and microbiota - driven chronic inflammation in the colon. combined rela, c - rel, and relb deficiency in iecs caused paneth cell apoptosis but not colitis, suggesting that nemo prevents colon inflammation by nf-b - independent functions. inhibition of receptor - interacting protein kinase 1 (ripk1) kinase activity or combined deficiency of fas - associated via death domain protein (fadd) and ripk3 prevented epithelial cell death, paneth cell loss, and colitis development in mice with epithelial nemo deficiency. therefore, nemo prevents intestinal inflammation by inhibiting ripk1 kinase activity - mediated iec death, suggesting that ripk1 inhibitors could be effective in the treatment of colitis in patients with nemo mutations and possibly in ibd. |
we present spontaneous retrobulbar hemorrhage in a 52-year - old woman with history of breast cancer and tamoxifen intake which was first thought to be an orbital metastasis. a 52-year - old woman with history of breast cancer and tamoxifen intake was referred due to severe proptosis and visual loss. after exploration, multiple fragments of dark brown mass in the retrobulbar area were excised. spontaneous retrobulbar hemorrhage is a rare condition that may have unknown etiologies, and its symptoms may mimic orbital metastasis. since both breast cancer and tamoxifen intake can cause coagulation disorders, they might be possible causes for retrobulbar hemorrhage in this case. retrobulbar hemorrhage may occur spontaneously or as a subsequent of a distinct etiology. some etiologies known until now include orbital vascular anomalies, subsequent trauma, surgery around the orbit, and systemic disease such as coagulopathy, toxic conditions, and uncontrolled hypertension. herein, we present a case of spontaneous retrobulbar hemorrhage that developed symptoms mimicking orbital mass and did not have known etiology except history of breast cancer and tamoxifen intake. a 52-year - old woman with history of breast cancer was referred to oculoplastic service, farabi eye hospital, tehran, iran for evaluating proptosis. a compressive orbital mass was detected in her mri and was taken to the neurologic department. she had complained of acute ocular pain and progressive visual loss in her left eye from 2 weeks earlier. she had been using tamoxifen since 5 years earlier after mastectomy due to her right breast cancer. she had no history of other systemic disease or trauma. on examination, left eye visual acuity was finger count at 1 m, and she had a left afferent pupillary defect. there was a severe inferolateral proptosis (28 mm in hertel exophthalmometry), secondary ptosis, and limitation of ocular motility in almost all directions, especially in elevation and adduction (fig. 1) routine lab tests and hematologic tests including bleeding time, clotting time, and platelet count were within normal limits without evidence of bleeding tendency. orbital ct scan showed an elliptical well - defined mass within the left intraconal space. it was a high - density and homogenous consistency mass that compressed and displaced the optic nerve to the supranasal side (fig. 2). orbital t1 weighted mri demonstrated an intraconal mass extending to the orbital apex that had a hypointense layer around the hyperintense mass without enhancement (fig. weighted mr scan, the intraconal mass was isointense but the superior part of the mass was hyperintense, and the other part that was near the orbital apex was hypointense (fig. the patient underwent supralateral lid crease orbitotomy. while opening the mass, at first a yellowish liquid was depleted, and then gelatinous, semiclotted blood was removed. finally, a solid mass that was similar to a hard blood clot remained (fig. 4). visual acuity dramatically improved to 20/30 one week after operation, and other clinical symptoms and signs improved completely. spontaneous retrobulbar hemorrhage without known etiology is rare. in many case reports differentiation between retrobulbar hematoma and tumor metastasis according to clinical symptoms has been impossible. metastatic breast cancer is the leading cause of orbital metastasis and is responsible for 4853% of orbital metastatic tumors. imaging such as ct scan and mri plays an important role to differentiate between metastatic breast cancer and retrobulbar hematoma. there are multiple characteristic features to diagnose metastatic breast cancer in mri and ct scan, including diffuse intraconal lesions, intra - muscle masses, and diffuse enhancement of retro - bulbar fat with abnormal heterogenous hypointensity and fibrotic infiltration and bone destruction contagious to the mass. but in our case, axial t1 weighted mri obtained 15 days after beginning of symptoms demonstrated a halo of low signal mass surrounding a high signal mass. these findings express a hematoma that has started to undergo physical changes and biochemical hemoglobin lysis. on the other hand, a deeper part of the hematoma had a solid part that was hypointense both at t1 and t2 and presented like a foreign body at mri (hypointense at t1 and t2). even though it was predictable that the mass could be a hematoma considering the acute onset and multilayer nature of the mass in mri, we did not offer a needle aspiration before surgery for two reasons : firstly, the deeper part of the mass seemed to be dense and solid according to mri, so we could not aspirate it easily. secondly, the most important differential diagnosis in this patient was orbital metastasis, and needle aspiration did not seem to be a good plan for its management. several cases of retrobulbar hemorrhage without definite etiology similar to our case has been reported.1, 2, 4 matsuura. reported a patient with orbital discomfort and exophthalmos without concomitant trauma, which firstly has been mistaken to be an orbital tumor. orbital ct scan revealed a round mass without enhancement, after surgical removal and diagnosis was blood cyst. reported a 75-year - old man who presented with sudden onset visual loss, orbital pain, and exophthalmos. patients with history of breast cancer are at higher risk for coagulation disorders compared with the healthy population. furthermore, hypercoagulability state could be induced by different medical interventions such as hormonal agents in this group of patients. numerous clinical studies revealed that tamoxifen could increase the risk of venous and arterial thrombosis rather than increasing bleeding tendency.6, 8 the presented case did not have any known disease that can cause retrobulbar hemorrhage except for history of breast cancer and tamoxifen intake. as there was not any evidence for orbital metastasis or disease recurrence in this patient, we can not easily attribute this orbital hemorrhage to them. the second most important suspicious cause for hemorrhage in this patient could be tamoxifen, if we could consider it as a cause for chronic mild disseminated intravascular coagulopathy. as we know, this is the first case report of spontaneous orbital hemorrhage in a patient with history of breast cancer and tamoxifen intake, so it could be considered as a basis for further research. | purposewe present spontaneous retrobulbar hemorrhage in a 52-year - old woman with history of breast cancer and tamoxifen intake which was first thought to be an orbital metastasis.case reporta 52-year - old woman with history of breast cancer and tamoxifen intake was referred due to severe proptosis and visual loss. orbital imaging showed an intra - conal mass. after exploration, multiple fragments of dark brown mass in the retrobulbar area were excised. microscopic diagnosis was blood clot. all of clinical signs and symptoms were improved 1 week after operation.conclusionspontaneous retrobulbar hemorrhage is a rare condition that may have unknown etiologies, and its symptoms may mimic orbital metastasis. since both breast cancer and tamoxifen intake can cause coagulation disorders, they might be possible causes for retrobulbar hemorrhage in this case. |
autologous transplantation of periodontal fibroblasts and stem cells may be a promising technique to induce tissue regeneration in the treatment of periodontal disease [14 ]. spheroid culture is a form of three - dimensional cell culture that promotes cell - matrix interaction and cellular differentiation without recourse to exogenous growth factors and has been widely used to study cellular differentiation, cell - cell interaction, hypoxia responses, and therapeutically oriented studies [6, 7 ]. in a recent study, 3d spheroidal cultures of periodontal fibroblasts were developed and characterized in vitro with respect to their potential use in conjunction with the biological membranes for periodontal tissue repair and regeneration. it was shown that synthetic and collagen - based membranes were both compatible with periodontal spheroids and stimulated cell proliferation and expression of proteins such as collagen type i, periostin, and runx2. however, the interaction of periodontal fibroblast spheroids with dentin has not been thoroughly investigated and it is not clear how the periodontal fibroblasts would behave in a 3d matrix in the presence of both dentin and biological membranes. dentin contains a complex mixture of proteoglycans, glycoproteins, sialoprotein, phosphoprotein, and other molecules which are trapped in the mineralized tissue. experimental studies have accentuated the interactions between dentin, cells from the tooth, and periodontal tissues and reveal dentin to be an adhesive, signaling, and migratory stimulus for various mesenchymal and inflammatory cells. it is believed that dentin exposure, as a consequence of periodontal disease or orthodontic movement, causes release of matrix components which might stimulate the surrounding environment. therefore, the aim of this study was to develop a three - dimensional in vitro model of periodontium including periodontal fibroblast spheroids cultured between dentin and different biological membranes to investigate the osteogenic and cementogenic differentiation potential of the periodontal spheroids within dentin - membrane complex. bovine jaws were retrieved from a local abattoir within 4 hours of commercial slaughter from skeletally mature, healthy, normal animals (18 months old). teeth were washed in distilled water and soft tissues were removed with a curette and the pulp was extirpated using a barbed brooch and dental bur under water. the enamel was removed using a bone cutter machine under water lubrication (vc-50, leco) and dentin was sliced to 1 mm thickness. samples were kept in 0.1% (w / v) thymol (sigma - aldrich, poole, uk) at 4c until use. prior to use, the dentin slices were washed 3 times with phosphate buffered saline (pbs) (sigma - aldrich, poole, uk), etched with 30% phosphoric acid for 30 second, washed in pbs, and finally preconditioned for 15 minutes in dulbecco 's modified eagle medium (dmem) (sigma - aldrich, poole, uk). commercially available periodontal ligament fibroblasts (hpdlf, 2630, sciencell research laboratories, ca, usa) were cultured in dmem supplemented with 10% fetal calf serum, (sigma - aldrich, poole, uk) 2 mm glutamine (sigma - aldrich, poole, uk), 50 u / ml penicillin (sigma - aldrich, poole, uk), and 50 u / ml streptomycin (sigma - aldrich, poole, uk). cells from subconfluent culture (passage 6) were released using a solution of 0.05% trypsin (sigma - aldrich, poole, uk) in 0.01% edta (sigma - aldrich, poole, uk), counted, and used to generate spheroid culture. spheroid cultures were initiated by seeding a total of 5 10 cells into 96-well plates coated with 1% agarose (sigma - aldrich, poole, uk). cultures were grown in the same basic media as in monolayer culture with additional l - ascorbic acid (sigma - aldrich, poole, uk) 50 g / ml. cultures were incubated in a humidified atmosphere of 5% co2/95% air at 37c. collagen membrane (bio - gide, geistlich biomaterials, switzerland) and polyglycolic acid (pga) membrane (synthecon incorporated, usa) were cut into squares of 10 mm 10 mm using an aseptic technique. pga was first disinfected in 100% isopropanol (sigma - aldrich, poole, uk) for 15 minutes followed by 3 rinses in pbs. membrane squares were placed inside wells of a 12-well plate and preconditioned with fresh complete medium for 10 minutes, twice. then the medium was discarded and a stainless steel ring (10 mm outer diameter and 6 mm inner diameter) was centrally placed on each membrane. periodontal spheroids suspended in 200 l of culture medium were pipetted into each ring and the space surrounding the ring was filled with 1 ml of medium. spheroids were incubated for 2 days before the ring was gently removed with sterile forceps. spheroids were allowed to grow on membranes for up to 20 days with a medium change twice a week. the squares of membranes with the attached cells were transferred onto the dentin discs with the fibroblast - cultured side of the membrane facing the dentin. the dentin - cells - membrane complexes were cultured for another 20 days in the complete culture medium. at the end of culture, the dentin - cells - membrane complexes were washed three times for 10 minutes using pbs and fixed in 10% buffered formalin (genta medical, york, uk). the decalcified samples were dehydrated in serial dilution of ethanol before being embedded in paraffin wax. samples were sectioned to 5 m thickness using a microtome (rm2235, leica, germany) and dried in a hot air oven for 1 hour at 60c. protein detection was carried out using immunostaining against osteocalcin, runx2, periostin, and cementum attachment protein (cap). the sections were pretreated with 10 mg / ml hyaluronidase (sigma - aldrich, poole, uk) in pbs for 30 minutes at 37c, followed by 2 mg / ml pronase (fluka biochemika, uk) in pbs for 30 minutes at the same temperature. in the case of runx2, trypsin was used as an additional antigen retrieval stage at 37c for 20 minutes. sections were washed with pbs followed by quenching endogenous peroxidase activity with 3% v / v in 50% methanol (fisher scientific, loughborough, uk) followed by washing with tris buffered saline (tbs) (sigma - aldrich, poole, uk). sections were then exposed to 3% w / v bovine serum albumin (bsa) (sigma - aldrich, poole, uk) in tbs / tween20 for 1 hour to avoid nonspecific staining. samples and positive controls were incubated with primary antibody overnight at 4c including mouse monoclonal osteocalcin 10 g / ml (abcam, ma, usa), rabbit polyclonal periostin 1 g / ml (abcam, ma, usa), rabbit polyclonal runx2 2 g / ml (abcam, ma, usa), and mouse monoclonal cap 1 g / ml (santa cruz biotechnology, ca, usa). for the negative control, all sections were washed with tbs and incubated with the appropriate secondary antibody for 1 hour at room temperature. the appropriate secondary antibody was prepared using a biotinylated secondary antibody kit (vectastain elite abc, vector laboratories, peterborough, uk) and the subsequent technique according to the manufacturer 's instructions. sections were then exposed to peroxidase substrate solution (dab - sk-4 100, vector laboratories, peterborough, uk) for the visualization of protein. generally both membranes adhered well on dentin surface. at 20 days, pga cultured with either periodontal spheroids or monolayers showed a better attachment on dentin compared to collagen membrane. pga showed a well - blended appearance and complete attachment onto the dentin surface ; however collagen membrane showed some nonadherent areas to the dentin surface mainly on the margins of the membrane (figure 1). histological examination of the collagen membranes seeded with either spheroids or monolayer fibroblasts showed presence of fibroblasts spread across the collagen membrane and at the interface between the membrane and the dentin surface (figures 2(a) and 2(b)). in a small proportion of sections there was evidence of separation of the membrane from the dentin surface in some areas. h&e sections of both spheroids and monolayer cells on pga membrane cultured on dentin showed closer attachment to the dentin surface compared to that of collagen membrane. the fibers of the pga membrane were clearly visible with presence of cells and matrix (figures 2(c) and 2(d)). a low level of staining was detected in the matrix at the surface of cells - membrane facing the dentin and more intense staining was detected inside the dentinal tubules and matrix slightly deep to the junction between membrane and dentin (figure 3). pdlf monolayer seeded onto collagen membrane and cultured on dentin showed a similar pattern of osteocalcin expression to that seen with spheroids. however at the interface between membrane and dentin the staining was more intense and through a greater depth of the cell - membrane construct. a layer of cellular fibrous matrix showed a gradient of staining, increasing towards the dentin. there was also marked staining of osteocalcin within dental tubules in a band of around 30 m, deep to the adjacent membrane. expression of osteocalcin by cells from spheroids within a pga membrane was broadly similar to that seen previously (figure 3(c)). staining of osteocalcin within the dentin was especially prominent. a low level of staining was found in the matrix ; however this was absent from superficial 75 m of the dentin - cell - membrane contact. pdlf monolayer seeded pga membrane expressed osteocalcin where it was stained within the extracellular matrix. intense staining was present in the dentin deep to the membrane but not in the dentin adjacent to the seeded membrane (figure 3(d)). there was no expression either in the centre of the membrane or at the dentin interface (figure 4(a)). pdlf monolayer cells seeded into collagen membrane also showed marked staining in the superficial layers. a band of staining was also seen within dentin at the interface (figure 4(b)). cells from spheroids in pga showed a very low level of expression in the superficial layers only (figure 4(c)). pdlf monolayer cells seeded into pga on dentin expressed runx2 in a wider superficial band than seen for collagen membrane (figure 4(d)). periostin expression was seen in the matrix throughout the construct in all four culture combinations (figure 5). in each case it was possible to detect a greater level expression in the matrix adjacent to the dentin in the case of spheroid and in some regions of the cell - pga - dentin construct. expression of cementum attachment protein was not detected in either pga or collagen membrane with cells from either monolayer or spheroids culture. figure 6 shows that no staining above background was present for spheroid - derived cells on collagen. the results of this study have shown that membranes seeded with pdlf - derived cells adhered to dentin but the dentin had a limited effect on differentiation of the cells. no clear differences between cells from monolayer or spheroids were seen nor were there significant differences in behavior between collagen and pga membranes. however it has been shown that both spheroids and monolayer cells - pga membrane attached better to the dentin than collagen membrane. in both cases the attachment is likely to be solely an adhesion between connective tissue and dentin rather than a true periodontal regeneration as neither insertion of fibers into dentin nor cementum secretion was seen by light microscopy. this finding is similar to that of an in vivo study using connective tissue grafts on the root surfaces. in their study, although there were some areas with true regeneration, the authors reported that most other areas presented with only connective tissue adhesion. there is also a report in vitro which showed an increase in proliferative activity and alkaline phosphatase activity when primary osteoblast cells were cultured on natural calcified dentin. osteocalcin is a well - established marker of bone, dentin, and cementum synthesis and thus its expression within a pdlf construct is expected. the cell - membrane constructs were opposed onto dentin with the intention of stimulating differentiation along a cementoblast - like lineage. in this regard, a slight increase in staining intensity of the basal cell layers might suggest that this has occurred. more strikingly, osteocalcin staining was strong in the dentin deep to the cells. as dentin peripheral to the cell - membrane was not stained, and the staining was parallel with the cell - membrane, it can be postulated that osteocalcin is being secreted by the cells. as the staining is in a layer at least 20 m deep to the cells, it is most likely that secreted osteocalcin has diffused into the dentin slice and bonded to the deeper surface within the slice. as the dentin was pretreated with 30% phosphoric acid there would be a surface of exposed dentinal tubules. the use of etchant was based on the concept that biochemical modification of the root surface could enhance cell migration and attachment to an exposed root surface [15, 16 ]. it has also been reported that exposed dentin together with bone morphogenetic protein (bmp) is capable of inducing cementogenesis in vivo. however despite these findings, it is debatable whether demineralization has a significant effect on reattachment clinically. the increased expression of runx2 distant to the dentin interface suggests that it is unlikely that dentin is exerting an inductive influence. runx2 can be induced by members of the tgf- family, which are likely to be expressed within a population of differentiating mesenchymal cells. in turn the findings of this study are consistent with the observations of ducy. who demonstrated that expression of runx2/cbfa1 in mouse embryo was not detectable before mineralization occurred. in this experiment there was no evidence of mineralization taking place which could be due to the lack of other mineralization factors. therefore, it is also doubtful whether the runx2 detection on the surface of cell - dentin - construct is really specific. there is a possibility of nonspecific staining of runx2 which is explained by the atypical staining pattern which is not seen in spheroid or other areas of the cell - dentin construct. ig - h3 which belongs to the same group as periostin has been demonstrated to inhibit mineralization of the periodontal ligament. showed that in the presence of vitamin d3, the level of ig - h3 mrna was markedly decreased. they also demonstrated that recombinant ig - h3 suppressed the alkaline phosphatase activity and bone nodule formation of cultured pdl cells. the absence of mineralization in these experiments may be partly accounted for by the expression of ig - h3 like protein indicated by generalized staining with an anti - periostin antibody. the absence of cementum attachment protein in this study indicates that neither calcified dentin nor a layer of exposed dentin alone was able to stimulate the periodontal fibroblasts to differentiate along the cementogenic lineage, although they arise from the same origin. this is supported by thomas and kollar who demonstrated that the combination of exposed dentin surface and follicular cells is not a sufficient stimulus for cementoblast differentiation and cementogenesis. since bovine dentin used in this study has different morphological, chemical composition, and physical properties compared to human dentin, further studies using human dentin were allowed to grow on membranes for up to 20 days prior to seeding on dentin slices. longitudinal studies are required to assess the effect of different seeding times on differentiation potential of the spheroids. 3d in vitro model of periodontium reported in this study contained dentin, pdl fibroblasts, and soft - tissue membranes. further research is underway to optimize the existing in vitro periodontal model by incorporating tissue engineered bone and oral mucosa to the 3d system. the advanced tissue engineered model can be used as a clinically relevant test system for the investigation of periodontal disease and the effects of different treatment modalities. periodontal ligament fibroblast cells exhibit some osteogenic potential when cultured in a 3d environment in the presence of dentin as shown by the expression of osteocalcin. however the interaction of cells and dentin in this study was unable to stimulate cementum formation. pga and collagen membranes did not have a significant effect upon differentiation, but fibroblast seeded - pga membrane demonstrated better attachment to dentin in comparison to fibroblast seeded - collagen membrane. | the aim of this study was to develop a three - dimensional in vitro model of periodontium to investigate the osteogenic and cementogenic differentiation potential of the periodontal ligament fibroblast (pdlf) spheroids within a dentin - membrane complex. pdlfs were cultured in both spheroid forms and monolayers and were seeded onto two biological collagen - based and synthetic membranes. cell - membrane composites were then transferred onto dentin slices with fibroblasts facing the dentin surface and further cultured for 20 days. the composites were then processed for histology and immunohistochemical analyses for osteocalcin, runx2, periostin, and cementum attachment protein (cap). both membranes seeded with pdlf - derived cells adhered to dentin and fibroblasts were present at the dentin interface and spread within both membranes. all membrane - cell - dentine composites showed positive staining for osteocalcin, runx2, and periostin. however, cap was not expressed by any of the tissue composites. it can be concluded that pdlfs exhibited some osteogenic potential when cultured in a 3d matrix in the presence of dentin as shown by the expression of osteocalcin. however the interaction of cells and dentin in this study was unable to stimulate cementum formation. the type of membrane did not have a significant effect upon differentiation, but fibroblast seeded - pga membrane demonstrated better attachment to dentin than the collagen membrane. |
patients with schizophrenia are at increased risk for several physical morbidities, including respiratory, infectious, metabolic, and cardiovascular diseases (cvds).1 many factors contribute to increase the risk for such conditions, and most of them are intertwined. first, the onset of mental disorder is correlated with the adoption of a series of behaviors that are implicated in an increased risk for such diseases, including smoking, inadequate diet, and sedentarism.2,3 those behaviors both aggravate and lead to other clinical conditions also prevalent among patients with schizophrenia, such as obesity, hypertension, diabetes mellitus, dyslipidemia, and cancer.2,46 the use of antipsychotic drugs is also known to be strongly correlated with increased risk for medical diseases in patients with schizophrenia.79 although antipsychotic medications are currently the gold - standard treatment for schizophrenia, both first - generation (fgas) and second - generation antipsychotics (sgas) are associated with increased risk for the aforementioned physical morbidities, with cvds being the most studied and having the most replicated studies.10,11 in fact, there is evidence that sgas, despite having demonstrated a higher efficacy in the treatment of schizophrenia and fewer adverse effects,12 are associated with higher risk for cvds than are fgas.1315 it has been speculated that this effect, added to the increasing prescription of these medications, might be responsible for an even higher burden for this population of patients and for health services in decades to come.2 the objective of the present study was to investigate the current physical health of a sample of outpatients with diagnoses of schizophrenia regarding metabolic disturbances and cardiovascular risk using clinical history and biometric and laboratorial parameter assessment. all outpatients of the schizophrenia research program (projesq) at the institute of psychiatry, clinics hospital, faculty of medicine, university of so paulo, brazil (instituto de psiquiatria do hospital das clinicas da faculdade de medicina da universidade de so paulo), who were willing and able to give a written informed consent, were included in this research, carried out in 2008. the inclusion criteria were a diagnosis of schizophrenia, both sexes, and age between 18 and 70 years. the diagnosis of schizophrenia was made after clinical interview, followed by discussion and agreement of the specialized team psychiatrist, in accordance to the diagnostic and statistical manual of mental disorders (dsm)-iv criteria for schizophrenia.16 the study was approved by the research ethics committee of hc - fmusp. data regarding clinical and demographical information, as well as information on patients habits (whether the patient currently smoked and performed regular physical activities) and medical treatment at the time of investigation (whether the patient was under any medical treatment other than psychiatric), were collected through interviews. the biometric data were collected through physical examination and involved weight, height, waist, and hip circumference measures, and blood pressure. laboratory analysis was conducted by the hospital s laboratory of clinical analysis (diviso de labo - ratrio central, hc - fmusp), and included blood glucose and lipid profle (total cholesterol, fractions, and triglycerides). overweight was defined as body mass index (bmi) equal to or higher than 25 kg / m. glucose intolerance, diabetes mellitus, dyslipidemia, and metabolic syndrome were defined according to the national cholesterol education program (ncep), national institutes of health (nih).17,18 the collected data were statistically analyzed using spss software (v 14.0 ; spss inc, chicago, il). the statistical methods include descriptive statistics, correlation analysis, chi - square test, mann - whitney test, variance analysis, and post hoc analysis for comparison between groups (tukey s honestly significant difference test). during the data analysis, patients were divided into four groups according to the current antipsychotics in use : 1) fgas, 2) sgas, 3) clozapine, and 4) polypharmacy (association of two or more antipsychotics). we included 261 patients who met the inclusion criteria and agreed to participate in the study. our patients had a broad variance of age (mean age 35.6 years ; standard deviation [sd ] 10.1) and duration of disorder (mean duration 13.8 years ; sd 8.2), though it would be possible to affirm that it consisted mostly of chronically ill patients (27.2% had more than 20 years of disorder). some indirect data suggested that a significant proportion of the patients presented with a severe form of the disorder, since approximately half of the patients needed at least one psychiatric hospital admission, and 18 had more than five admissions. almost 40% of the sample were using clozapine as monotherapy, 10% in association with another antipsychotic (in the majority of cases, due to refractoriness of the disorder). concerning life habits, we found a high prevalence of smoking (55.2%), mainly among men. the demographics, habits, biometrics, and laboratorial information are summarized in table 1. the use of antidepressants was found in almost 30% of the sample ; no association was found concerning its use and weight gain or other metabolic disturbances. the association of valproate with clozapine was the most common association of mood stabilizers and antipsychotics in this sample (= 25.6, p = 0.012, df = 12), mainly indicated for prevention and control of seizures related to high doses of clozapine. we found that a high proportion of patients had bmis above normal limits (70%), and 31.4% were considered obese. the fasting blood glucose was found to be above normal limits in 30.9% of the sample, suggesting a high prevalence of glucose intolerance and diabetes mellitus that were either inadequately controlled or undiagnosed, and hence not being treated. some parameters of lipid profile (such as total cholesterol and low - density lipoprotein (ldl) were correlated with patients ages (pearson correlation = 0.191, p = 0.002 and pearson correlation = 0.157, p = 0.011, respectively, for total cholesterol and ldl). however, there was no correlation with the duration of disorder or type of antipsychotic in use (p = 0.296, df = 3). bmi showed no correlation with patient age or duration of disorder, but was correlated with total cholesterol and ldl (respectively p < 0.001 and p = 0.002), and inversely correlated with high - density lipoprotein (hdl) (p = 0.011), which was an expected finding. we did not find any significant correlation between dyslipidemia and patient age or duration of disorder (pearson correlation = 0.068, p = 0.148 and pearson correlation = 0.042, p = 0.285, respectively), nor with use of any type of antipsychotic (= 1.554, p = 0.460). applying the same method for metabolic syndrome, we found an association between age and metabolic syndrome, which was more prevalent in older patients (pearson correlation = 0.138, p = 0.029) ; however, that was not true for duration of the disorder (pearson correlation = 0.074, p = 0.234), nor for use of any type of antipsychotic (= 0.382, p = 0.826). even after dividing the sample in two groups having extremely different durations of disorder, separating those with less than 3 years of disorder (n = 22) and those with more than 20 years of disorder (n = 71), we still could not find any significant difference between those groups concerning clinical parameters, prevalence of diabetes melitus, dyslipidemia, or metabolic syndrome. there was no association between metabolic disturbances and pharmacological medical treatment or appropriate lifestyle habits (not smoking and being physically active). there was no significant difference between the samples of different types of antipsychotics regarding risk factor or metabolic disturbances, except for ldl parameters (p = 0.032, ci 95% : 0.5935.4). nevertheless, after a post hoc evaluation (scheffe s test) only a trend for significance remained (p = 0.07) between the polypharmacy and fga groups. table 3 shows information regarding the association between the types of antipsychotics and metabolic parameters in this sample. our patients had a broad variance of age (mean age 35.6 years ; standard deviation [sd ] 10.1) and duration of disorder (mean duration 13.8 years ; sd 8.2), though it would be possible to affirm that it consisted mostly of chronically ill patients (27.2% had more than 20 years of disorder). some indirect data suggested that a significant proportion of the patients presented with a severe form of the disorder, since approximately half of the patients needed at least one psychiatric hospital admission, and 18 had more than five admissions. almost 40% of the sample were using clozapine as monotherapy, 10% in association with another antipsychotic (in the majority of cases, due to refractoriness of the disorder). concerning life habits, we found a high prevalence of smoking (55.2%), mainly among men. the demographics, habits, biometrics, and laboratorial information are summarized in table 1. the use of antidepressants was found in almost 30% of the sample ; no association was found concerning its use and weight gain or other metabolic disturbances. the association of valproate with clozapine was the most common association of mood stabilizers and antipsychotics in this sample (= 25.6, p = 0.012, df = 12), mainly indicated for prevention and control of seizures related to high doses of clozapine. we found that a high proportion of patients had bmis above normal limits (70%), and 31.4% were considered obese. the fasting blood glucose was found to be above normal limits in 30.9% of the sample, suggesting a high prevalence of glucose intolerance and diabetes mellitus that were either inadequately controlled or undiagnosed, and hence not being treated. some parameters of lipid profile (such as total cholesterol and low - density lipoprotein (ldl) were correlated with patients ages (pearson correlation = 0.191, p = 0.002 and pearson correlation = 0.157, p = 0.011, respectively, for total cholesterol and ldl). however, there was no correlation with the duration of disorder or type of antipsychotic in use (p = 0.296, df = 3). bmi showed no correlation with patient age or duration of disorder, but was correlated with total cholesterol and ldl (respectively p < 0.001 and p = 0.002), and inversely correlated with high - density lipoprotein (hdl) (p = 0.011), which was an expected finding. we did not find any significant correlation between dyslipidemia and patient age or duration of disorder (pearson correlation = 0.068, p = 0.148 and pearson correlation = 0.042, p = 0.285, respectively), nor with use of any type of antipsychotic (= 1.554, p = 0.460). applying the same method for metabolic syndrome, we found an association between age and metabolic syndrome, which was more prevalent in older patients (pearson correlation = 0.138, p = 0.029) ; however, that was not true for duration of the disorder (pearson correlation = 0.074, p = 0.234), nor for use of any type of antipsychotic (= 0.382, p = 0.826). even after dividing the sample in two groups having extremely different durations of disorder, separating those with less than 3 years of disorder (n = 22) and those with more than 20 years of disorder (n = 71), we still could not find any significant difference between those groups concerning clinical parameters, prevalence of diabetes melitus, dyslipidemia, or metabolic syndrome. there was no association between metabolic disturbances and pharmacological medical treatment or appropriate lifestyle habits (not smoking and being physically active). there was no significant difference between the samples of different types of antipsychotics regarding risk factor or metabolic disturbances, except for ldl parameters (p = 0.032, ci 95% : 0.5935.4). nevertheless, after a post hoc evaluation (scheffe s test) only a trend for significance remained (p = 0.07) between the polypharmacy and fga groups. table 3 shows information regarding the association between the types of antipsychotics and metabolic parameters in this sample. our analysis suggests that this is a population with high rates of comorbidities, both mental and physical. the high number of patients under antidepressant treatment might indicate an increased prevalence of depression, which is a phenomenon often observed in samples of patients with schizophrenia.19 the high prevalence of tobacco smoking and sedentariness, despite also being frequent among those patients, raises serious concerns, since both habits are implicated in increased risk for cvds. in fact, we found a high prevalence of several other risk factors for cvds in our sample, including a large number of overweight patients, inadequate lipid profiles, and high levels of fasting blood glucose. such increased prevalence of risk factors for cvds is highlighted when contrasted with findings from the healthy brazilian population, as described in a large epidemiologic study.20 in this sample, the prevalence of obesity was 11.3% among men and 11.2% among women, whereas in our sample, such proportions were 29.7% and 35.3%. also, the prevalence of dyslipidemia was 16.5%, whereas in our sample, its prevalence was 73.2%. this significant increase in risk factors was also found in a similar population in brazil, in a study conducted by the federal university of rio grande do sul, porto alegre, brazil.21 another brazilian study also addressed the prevalence of metabolic disorders among patients with psychiatric disorders and showed elevated rates of this condition (31.8% in schizophrenic disorder, 38.3% in bipolar disorders, and 48.1% in depression), though neither the psychiatric diagnosis nor the use of antipsychotics was associated with metabolic syndrome after logistic regression analysis, which was probably due to the small sample size.22 patients on different types of antipsychotics showed no difference regarding metabolic risk, nor with the use of polypharmacy, as suggested by other studies.23 the nonsignificant lower levels of ldl seen in patients using polypharmacy in comparison with the fga patients (p = 0.07) might be explained by patients with polypharmacy having a more severe form of the disorder in comparison with patients with fgas, which might imply more - frequent clinical appointments and evaluations, hence more attention and lifestyle counseling (diet, exercises, etc), and thus decreased risk factors for cvds. although worse lipid profiles were associated with patient age, which is expected in the general population,24 the duration of the disorder was not associated with different lipid profiles or bmi. some studies have revealed that the metabolic alterations due to use of antipsychotics (especially lipid profile changes and weight gain) occur in a matter of months, reaching a plateau after approximately 9 months of use.25,26 concerning the analysis of an early event in a sample of chronically ill patients, it comes as no surprise that we found no association between metabolic parameters and duration of the disorder. nevertheless, it is clear that the exposure to antipsychotic medications is a risk, in this population, for development of metabolic disorders at a very early stage, resulting in a large population of individuals chronically exposed to several risk factors for cvds and other diseases.27 it is important to notice that only a small proportion of patients in our sample was under pharmacological treatment for physical diseases, which, given the high prevalence of metabolic disorders and increased risk for cvds, suggests poor access to medical or health care and/or poor compliance with treatment. this phenomenon is extensively described in the scientific literature as a worldwide problem concerning patients with schizophrenia.2,28,29 the main limitation of our study is its cross - sectional design, which did not allow any conclusions regarding causal effects of the variables analyzed. furthermore, we did not include a control group, and some variables had only a few subjects allocated, such as physically active or pharmacological medical treatment, making the analysis difficult. a better investigation on the matter might be done by choosing the sample and controlling it using physical activities as a parameter, as was done in other studies with positive results.30,31 however, we believe that the naturalistic nature of the present study and the relatively large sample might create a reliable portrait of the population of outpatients under treatment, revealing a high prevalence of cardiovascular risk factors, physical comorbidities, and the need for clinical assessment and liaison with the general practitioner for adequate clinical treatment. this reinforces the results found in the study by leito - azevedo.21 patients with schizophrenia, regardless of age or type of antipsychotic medication in use, were found to be at increased risk for many physical disturbances, including weight gain, dyslipidemia, and increased risk for cvds ; and may benefit from clinical evaluation and adequate treatment, as recommended by international protocols. we suggest that an intensive and appropriate approach should be taken to assure that these patients receive adequate clinical referral and treatment. | backgroundin the last few decades, a large number of studies have produced compelling evidence that patients with schizophrenia are at increased risk for developing several medical conditions and diseases, including obesity, metabolic disturbances, and cardiovascular diseases. several protocols have been designed with the aim of reducing such risk.objective:to investigate current physical health status in a population of outpatients with schizophrenia.methods:a cross - sectional study was conducted in our outpatient clinic, selecting subjects who met dsm - iv diagnosis criteria for schizophrenia. data were collected regarding clinical characteristics, lifestyle, medication in use, and biometric and laboratory parameters.results:a total of 261 patients were included. we found a high prevalence of elevated body mass index (bmi. 25) (70%), dyslipidemia (73.2%), and metabolic syndrome (28.7%). patients ages were associated with worsened lipid profiles, but other variables, such as disorder duration or type of antipsychotic in use, were not associated with any metabolic disturbance. despite the increased prevalence of these conditions, only a small portion of the sample was under regular medical treatment.conclusion:outpatients with schizophrenia show signs of poor physical health conditions. these findings reinforce the need for an intensive and appropriate approach to assure that these patients receive adequate clinical referral and treatment. |
soybean meal is an ingredient of choice to supply energy and proteins to layers and broilers. because of that, costs and availability of soybean meal are strongly correlated with the price of agricultural commodities on the world market [1, 2 ]. the trypsin inhibitors of soybean grain are well characterized and are an important determinant of nutritive value [3, 4 ]. toasting is suggested within other heat processing procedures to reduce trypsin inhibitors in soybean grains or meals [6, 7 ]. in benin, only jupiter variety of soybean is produced ; and the toasting method is adopted for processing grains and meal. on other side, laying performance of hens is lower when they are too fat. thus, soybean grains even toasted are used at lower rate in pullets and layers diets than broilers diets. farmers reject the utilization of toasted soybean grains in layers diet in benin ; but included efficiently up to 22% of toasted soybean grains in broiler diet. in tropical climate, important increase of dietary energy may be result a decrease of feed intake by poultry. toasted soybean grains have a high content of energy and protein, it is important to evaluate their optimal rate in diets of pullets and layer hens in hot and humid climate, mainly for birds from heavy lines often used in africa. the study was conducted in a poultry house (20 m 15 m). the house was divided into twelve (12) partitions of 25 m each. each partition had three feeders (1.5 m of length) and two automatic drinkers. a total of 1000 harco (rhode island red plymouth rock) day - old chicks were imported from nigeria. they were vaccinated against newcastle disease, gumboro, infectious bronchitis, and avian pox. chicks were also treated regularly against helminthes and coccidiosis. at three - week - old (starting of the experiment), the average weight of chicks was 206.5 2.69 g. chicks were divided into 12 groups of 81 chicks each. thus, at pullet and laying phases, there were 3.2 chicks / m. diets were formulated by phases. at starter (4 to 8 weeks - old), pullet (9 to 18) and laying (19 to 26) phases, respectively, four diets were formulated (tables 1, 2, and 3). in diets, soybean grains were included at 0% (r0, control), 5% (r5), 10% (r10), and 15% (r15). soybean grains were toasted before the processing of diets to reduce trypsin inhibitors effect. at each phase, the same quantity of feed was provided to each replicate and the birds consumed all the available feed. they are used to compare the efficiency of diets. the general linear model (glm) a significant effect of diets is stated when p value (p) is less than 0.05. the effects of replication and of the interaction between diets and replications were not significant (p > 0.05). hence, the statistical model was (1)yi=+gi+i, where yi is the observation for dependent variables ; is the general mean ; gi is the fixed effect of soybean grains ; i is the residual error. the results are presented in two phases : the growth phase (starting and pullet phases) and the laying phase. performances during the five weeks of starting phase are shown in table 4 and figure 1. no significant difference (p > 0.05) was recorded on, daily weight gain, mortality and feed conversion ratio in spite of difference in feed composition between diets. the inclusion of toasted soybean grains at different rates in the diet did not affect significantly the growth and survivability of chicks. these results suggest a similar efficacy of diets at starter phase. also, during the pullet phase the growth performance was not significantly affected by the diet (table 5 and figure 1). however, the feed conversion ratio and the mortality rate increased at pullet compared to the starter phase. at starter and pullet phases, the prices of the formulated feeds decreased when the soybean grains rate increased in the diet (table 6). thus, at pullet phase, the feeding cost per kg of live body weight gain decreased in soybean - based diets compared to the control diet (table 7). however, at starter phase, due to the light decrease of live body weight gain in the soybean grains - based diets, the feeding cost increased (table 6). the soybean grains based diets are therefore more efficient at pullet phase than at starter phase. the feed efficiency evaluated at the end of pullet phase, demonstrated that for each unit of money invested in feed, the revenue from the selling of the live weight gain varied between 2.15 and 2.48 times (table 7). the efficiency of the diet increased significantly (p 0.05). thus, the feeding cost per egg decreased significantly during the first month of laying, but not later (table 9). respectively, in first and second months, the feeding cost in r15 diet represented about 32% and 86% of that in control diet, indicating a better efficiency of r15 diet compared to the control diet and the two other soybean grains - based diets. the similarity on growth performance of pullets up to 18-week - old demonstrates the efficiency of toasted soybean grains based diets in general and r15 diet in particular. the live body weight gain of pullets was higher than reported, and they grew regularly. thus, the final weights of pullets (1366 to 1456 g) are in the range of 1341 to 1594 g recorded at 20-week - old in shika - brown pullets. the live weight of pullets at the starting of the laying period is one of more important criteria focused by farmers. in this study, at 18-week - old the live weight of pullets was very similar in r0 and r15 diets (1454 g versus 1456 g). during pullet phase the feed conversion ratios were lower than the 5.73 to 6.62 found between 8 and 20 weeks in hy - line pullets. furthermore, the light increase of mortality rate in soybean based diets compared to control diet was not significant. these results confirmed the efficacy of all the diets. up to 15% of toasted soybean grain up to peak, the laying rate in r15 diet was the highest, with a significant difference from 24 to 26 weeks of age. thus, efficiency of toasted soybean grains based diets was also effective during the first eight laying weeks. the average laying rate was higher than 63.868.4%, 64.0%, and 61.4% recorded respectively with harco and hy - line layers up to 28-week - old. at laying phase, the feed conversion ratio was also lower in r15 diet compared to the control diet. however, the feed conversion ratios were higher than 2.814.07 g feed / g egg. no significant diet effect was found on hens ' mortality. in the second month, the egg weights were significantly higher in r15 diet, but lower than the 60 g reported by other [1517 ]. in first month, the egg weights were in the range of 41.047.4 g. energy requirement of hens is lower in hot and humid climate than in temperate climate. soybean grains being very energetic, during the latest laying weeks, hens could get fat. that might reduce their laying performance. an evaluation of the laying performance during the whole laying period is therefore relevant for heavy layers breeds fed with whole toasted soybean grains in hot and humid climate. the incorporation of toasted soybean grains in diets reduces feed prices. at growth and laying phases, thus, feeding cost and feed efficiency improved significantly in soybean - based diets during the growth phase of pullets. the feeding of harco pullets with toasted soybean grains diets can be therefore recommended in hot and humid regions. the significant decrease of feeding cost from first to second laying months was due to the increase of laying rate until the peak. this study shows the efficiency of toasted soybean - based diets in harco pullets and hens feeding in hot and humid climate. the toasting processing used in benin to improved soybean grain efficacy in poultry diet is therefore suitable. however, the price of toasted soybean grains should be kept at a level where the energy and protein costs from these grains should be lower than those from other main energy and protein sources like soybean and fish meals. | the aim of this paper was to evaluate the effects of toasted soybean grains on bioeconomic performance of pullets and layer hens in hot and humid environment. a total of 972 three - week - old harco chicks were divided into 12 groups. at starter, pullet and laying phases, birds were fed four diets containing 0% (r0), 5% (r5), 10% (r10), and 15% (r15) of soybean grains. results showed similar feed intake, body weight gain, laying rate, feed conversion ratio, and mortality rate between dietary treatments at each phase. the egg weight increased significantly in diet r15 (p < 0.05). the use of soybean grains reduced the feed prices. feeding cost decreased significantly (p < 0.05) during growth and laying phases in soybean grains added diets. feeds efficiency increased significantly (p < 0.05) with the increase of dietary soybean grains rate. properly toasted soybean grains can be therefore included up to 15% in heavy line layer hens ' diet in tropical conditions. |
in the effort to attain the millennium development goals (mdgs) 4 and 5, which are to reduce child mortality and improve maternal health, respectively,1 the department of health (doh) of the philippines mandated the implementation of the essential intrapartum and newborn care (einc) protocol in both public and private hospitals in 2009 as supported by the world health organization (who).2 the einc practices are evidence - based standards for safe and quality care of birthing mothers and their newborns within the 48 hours of the intrapartum period (labor and delivery) and 1 week of life for the newborn. these practices involve continuous support to the mother during labor and delivery by allowing a companion of choice, mobility and position of choice, nonpharmacologic pain management, and spontaneous pushing in the semi - upright position. the progress of labor is monitored using a partograph to detect obstructed labor and other complications. episiotomy (perineal incision) is not done, unless necessary to prevent excessive perineal bleeding. approaches in the management of the third stage of labor are shifted from physiologic to active, wherein the delivery of the placenta is hastened instead of waiting for its spontaneous delivery to reduce blood loss.2 active management of third stage of labor (amtsl) involves the injection of 10 units of oxytocin intramuscularly to the mother after the delivery of the baby, controlled cord traction (cct) with counter traction on the uterus, and uterine massage.3 recommended einc practices for newborn care are time - bound interventions at the time of birth, which include immediate and thorough drying of the newborn, early skin - to - skin contact between mother and the newborn, properly timed cord clamping and cutting, and nonseparation between mother and newborn for early breastfeeding initiation.2 as the philippine government and private birthing institutions are gradually implementing said protocol, pregnant women in the marginalized communities still entrust their birthing care to traditional birth attendants (tbas). a tba, as defined by the who, is a person who provides obstetric care services using acquired knowledge from other tbas or through experience.4 even nowadays, especially in developing countries, many community women still prefer the services of tbas because they are always available as they live in the same community, sharing the same culture and beliefs, and mostly they are cheaper options compared to trained or professional health service providers.5 maranao means people of the lake, referring to the indigenous people who inhabited the grounds around lake lanao, philippines. the maranao is one of the last tribes in mindanao adapting to modern society and not completely losing its ethnic identity. it is one of the largest islamic groups in the philippines.6 infant delivery in remote muslim communities is mostly handled by tbas.7 in an attempt to determine the quality of birthing services the maranaos in the far - flung areas are receiving, this study was conducted to determine the profile and birthing practices among maranao tbas to assess if their birthing interventions are safe and compliant with the ideal interventions set by the doh. the study used a descriptive research design to determine the respondents profile and birthing practices, both modern and traditional. the sample of this study consisted of 50 maranao tbas between 31 and 85 years old who had attended at least ten delivery cases, regardless of sex, education, occupation, source of learning skills, and recruitment, selected through the snowball sampling technique. snowball sampling, also known as chain - referral sampling, is a non - probability sampling technique wherein existing study participants are asked to assist the researchers in identifying other potential subjects from their acquaintances since tbas are not easy to locate. a researcher - made survey tool was used to determine the respondents modern birthing practices utilizing the einc protocol. to determine their profile and traditional birthing practices, items from a study by saravanan and the respondents personal claims therein. the questions were translated to the maranao language and the instrument was pretested with ten maranao tbas not involved with the final conduct of the study and analyzed through cronbach s alpha. actual interaction with each respondent was done to secure written informed consent to participate in the study and to gather the needed information through an interview. to analyze the data gathered, frequency and percentage distribution and weighted mean the study was approved by the institute ethics review committee (ierc) of mindanao state university - iligan institute of technology (msu - iit) before its final conduct. as depicted in table 1, the respondents are mostly between 51 and 60 years old, followed by the 6170 years age range. this implies that tbas are predominantly older, thus perceived to have ample personal experiences in terms of taking care of a woman during pregnancy, labor, and delivery. most of them are females, so they are more aware of what to expect and what are the special needs of the woman during labor and delivery. the majority of them had attended islamic schools but were unable to attain formal education. the respondents do not have a stable occupation and are mostly hilot, or traditional touch therapists, who treat minor illnesses such as fever, coughs and colds, sprains, and some bone dislocations through alternative medicine massage. they just receive a small amount of money or agricultural products of any kind for their services. furthermore, 54% of the respondents had acquired the skills in handling delivery from their senior family members and 46% from other tbas, and none of them had acquired formal training from professional health personnel. moreover, 60% of the respondents had been influenced and recruited by their senior family members and 40% by other tbas to become birth attendants. as shown in table 2, this implies that they have fair performance in terms of modern birthing interventions and their practices are not parallel with the safe and ideal birthing protocol set by doh. table 2 also shows that the only modern or ideal interventions that the respondents always practice are to wash their hands before handling delivery and encouraging the postpartum mothers to breastfeed their babies. this concept applies to all settings where health care is performed, such as home care by birth attendants.8 encouraging mothers to breastfeed is a very good practice, since breastfeeding is not only beneficial to the health of the baby but also it develops the physical and emotional bond between mother and child and even helps the mother recover from childbirth more quickly.9 the respondents do not practice comfort measures to the mother during labor such as allowing her to move freely, do breathing exercises, or even have something to eat. they have no observance of sterility, as they do not wear sterile gloves upon handling delivery. health care providers must wear sterile gloves in order to avoid the risk of contamination with the patient s blood and other body fluids.10 likewise, there is a risk of maternal and neonatal sepsis as there is no protection from microorganisms, which may come from the tba s hands. only sometimes, they practice keeping the baby warm and dry and putting the newborn in skin - to - skin contact with the mother ; failure to follow these practices can predispose a baby to hypothermia. hypothermia has been found to increase the risk of metabolic acidosis, jaundice, respiratory distress, hypoglycemia, pulmonary hemorrhage, and death, regardless of the newborn s weight and gestational age.11 the respondents do not consider the cord pulsations as they cut the umbilical cord immediately after the baby is born. the timing of cord clamping and cutting within 13 minutes after the delivery of the baby improves the iron status of the infant.12 the respondents also do not practice the injection of oxytocin because they do not know its importance and availability and they do not have the capacity to do it. they do not perform cct and counter traction on the uterus to remove the placenta, since they wait for its spontaneous delivery.. these interventions during the third stage of labor do not correspond to the recommendations of the who. in 2012, the who recommended amtsl as prevention for postpartum hemorrhage, which has three components, namely : 1) intramuscular injection of a uterotonic, preferably oxytocin, to the mother after the delivery of the baby ; 2) performing cct to deliver the placenta ; and 3) massaging the uterine fundus after placental delivery. with a trial to this approach, it was found that administration of a uterotonic is most important to reduce hemorrhage and cct and that immediate fundal massage can be optional.3 the respondents do not perform the injection of vitamin k (clotting factor) to the newborn, as they do not have any idea about it, which puts the newborn at increased susceptibility to bleeding disorders. intramuscular injection of vitamin k prophylaxis is safe and the drug of choice for the prevention of hemorrhagic disease of the newborn.13 the respondents never refer a mother or baby to a health facility for complications. tbas are less likely to recognize most maternal complications.14 they also do not advise infant immunization, so the baby is not protected against infectious diseases. immunization is very important for infants and children since they are vulnerable to infections, which may result in fatal complications.15 the poor performance of the modern birthing practices among the respondents thereby increases the risk of maternal and neonatal complications related to delivery. as depicted in table 3, the respondents often practice the traditional ways in handling delivery. the respondents often use fundal maneuver to push the baby out, which may result in maternal and newborn injuries and death. fundal maneuver is the application of manual pressure to the uppermost part of the uterus directed toward the birth canal to assist spontaneous vaginal delivery and to avoid prolonged second stage of labor. possible complications include uterine rupture, anal sphincter damage, newborn fractures or brain damage, and increased blood transfusion between the mother and her unborn baby, which may result in rh sensitization and transmission of viral diseases from mother to baby.16 the respondents always practice umbilical cord milking (ucm) prior to the ligation and cutting of the cord shortly after birth. ucm is a safe procedure and improves hemoglobin and iron status at 6 weeks of life among term and near - term neonates.17 though ucm is associated with some benefits and no adverse effects in the immediate postnatal period in preterm infants (gestational age <33 weeks), still, further studies are warranted to assess the effect of ucm on neonatal and long - term outcomes.18 the respondents often practice the traditional method of ligating the umbilical cord before cutting by using sewing thread. since the umbilical cord tends to shrink after birth, this type of ligature proves somewhat unreliable in preventing hemorrhage. the more usual method in developed countries currently is plastic or metal clamps, which produce safe, reliable constriction and have been very successful in preventing bleeding from the navel.19 moreover, the respondents always use unsterile sharpened bamboo in cutting the umbilical cord, which increases the risk of neonatal tetanus, omphalitis, and sepsis.20 the respondents often wait approximately 30 minutes for the placenta to deliver spontaneously, which allows excessive blood loss, leading to a very serious complication : hemorrhage. this practice contradicts the amtsl of the einc protocol, which involves cct with counter traction on the uterus after a strong uterine contraction, stimulated by intramuscular injection of 10 units of oxytocin. amtsl decreases the length of the third stage of labor, average blood loss, number of postpartum hemorrhage cases, and need for blood transfusion.3 furthermore, the respondents practice newborn bathing immediately after birth, which may cause hypothermia, disorientation resulting in altered crawling reflex, and removal of the natural protection from infection, such as the maternal bacteria and the vernix caseosa, which is a potent inhibitor of escherichia coli.21 although the majority of the respondents always encourage breastfeeding, there are those that sometimes advise discarding the colostrum, the breast milk produced during the early days postpartum, as perceived to be dirty because of its yellowish color, which can be associated with pus. colostrum has a yellow to orange color because of its many substances that protect the baby from infections.22 as depicted in table 1, the respondents are mostly between 51 and 60 years old, followed by the 6170 years age range. this implies that tbas are predominantly older, thus perceived to have ample personal experiences in terms of taking care of a woman during pregnancy, labor, and delivery. most of them are females, so they are more aware of what to expect and what are the special needs of the woman during labor and delivery. the majority of them had attended islamic schools but were unable to attain formal education. the respondents do not have a stable occupation and are mostly hilot, or traditional touch therapists, who treat minor illnesses such as fever, coughs and colds, sprains, and some bone dislocations through alternative medicine massage. they just receive a small amount of money or agricultural products of any kind for their services. furthermore, 54% of the respondents had acquired the skills in handling delivery from their senior family members and 46% from other tbas, and none of them had acquired formal training from professional health personnel. moreover, 60% of the respondents had been influenced and recruited by their senior family members and 40% by other tbas to become birth attendants. as shown in table 2, the respondents practice the modern and ideal birthing interventions only sometimes. this implies that they have fair performance in terms of modern birthing interventions and their practices are not parallel with the safe and ideal birthing protocol set by doh. table 2 also shows that the only modern or ideal interventions that the respondents always practice are to wash their hands before handling delivery and encouraging the postpartum mothers to breastfeed their babies. this concept applies to all settings where health care is performed, such as home care by birth attendants.8 encouraging mothers to breastfeed is a very good practice, since breastfeeding is not only beneficial to the health of the baby but also it develops the physical and emotional bond between mother and child and even helps the mother recover from childbirth more quickly.9 the respondents do not practice comfort measures to the mother during labor such as allowing her to move freely, do breathing exercises, or even have something to eat. they have no observance of sterility, as they do not wear sterile gloves upon handling delivery. health care providers must wear sterile gloves in order to avoid the risk of contamination with the patient s blood and other body fluids.10 likewise, there is a risk of maternal and neonatal sepsis as there is no protection from microorganisms, which may come from the tba s hands. only sometimes, they practice keeping the baby warm and dry and putting the newborn in skin - to - skin contact with the mother ; failure to follow these practices can predispose a baby to hypothermia. hypothermia has been found to increase the risk of metabolic acidosis, jaundice, respiratory distress, hypoglycemia, pulmonary hemorrhage, and death, regardless of the newborn s weight and gestational age.11 the respondents do not consider the cord pulsations as they cut the umbilical cord immediately after the baby is born. the timing of cord clamping and cutting within 13 minutes after the delivery of the baby improves the iron status of the infant.12 the respondents also do not practice the injection of oxytocin because they do not know its importance and availability and they do not have the capacity to do it. they do not perform cct and counter traction on the uterus to remove the placenta, since they wait for its spontaneous delivery. nevertheless, they often practice fundal massage after the placental delivery. these interventions during the third stage of labor in 2012, the who recommended amtsl as prevention for postpartum hemorrhage, which has three components, namely : 1) intramuscular injection of a uterotonic, preferably oxytocin, to the mother after the delivery of the baby ; 2) performing cct to deliver the placenta ; and 3) massaging the uterine fundus after placental delivery. with a trial to this approach, it was found that administration of a uterotonic is most important to reduce hemorrhage and cct and that immediate fundal massage can be optional.3 the respondents do not perform the injection of vitamin k (clotting factor) to the newborn, as they do not have any idea about it, which puts the newborn at increased susceptibility to bleeding disorders. intramuscular injection of vitamin k prophylaxis is safe and the drug of choice for the prevention of hemorrhagic disease of the newborn.13 the respondents never refer a mother or baby to a health facility for complications. tbas are less likely to recognize most maternal complications.14 they also do not advise infant immunization, so the baby is not protected against infectious diseases. immunization is very important for infants and children since they are vulnerable to infections, which may result in fatal complications.15 the poor performance of the modern birthing practices among the respondents thereby increases the risk of maternal and neonatal complications related to delivery. as depicted in table 3, the respondents often practice the traditional ways in handling delivery. the respondents often use fundal maneuver to push the baby out, which may result in maternal and newborn injuries and death. fundal maneuver is the application of manual pressure to the uppermost part of the uterus directed toward the birth canal to assist spontaneous vaginal delivery and to avoid prolonged second stage of labor. possible complications include uterine rupture, anal sphincter damage, newborn fractures or brain damage, and increased blood transfusion between the mother and her unborn baby, which may result in rh sensitization and transmission of viral diseases from mother to baby.16 the respondents always practice umbilical cord milking (ucm) prior to the ligation and cutting of the cord shortly after birth. ucm is a safe procedure and improves hemoglobin and iron status at 6 weeks of life among term and near - term neonates.17 though ucm is associated with some benefits and no adverse effects in the immediate postnatal period in preterm infants (gestational age <33 weeks), still, further studies are warranted to assess the effect of ucm on neonatal and long - term outcomes.18 the respondents often practice the traditional method of ligating the umbilical cord before cutting by using sewing thread. since the umbilical cord tends to shrink after birth, this type of ligature proves somewhat unreliable in preventing hemorrhage. the more usual method in developed countries currently is plastic or metal clamps, which produce safe, reliable constriction and have been very successful in preventing bleeding from the navel.19 moreover, the respondents always use unsterile sharpened bamboo in cutting the umbilical cord, which increases the risk of neonatal tetanus, omphalitis, and sepsis.20 the respondents often wait approximately 30 minutes for the placenta to deliver spontaneously, which allows excessive blood loss, leading to a very serious complication : hemorrhage. this practice contradicts the amtsl of the einc protocol, which involves cct with counter traction on the uterus after a strong uterine contraction, stimulated by intramuscular injection of 10 units of oxytocin. amtsl decreases the length of the third stage of labor, average blood loss, number of postpartum hemorrhage cases, and need for blood transfusion.3 furthermore, the respondents practice newborn bathing immediately after birth, which may cause hypothermia, disorientation resulting in altered crawling reflex, and removal of the natural protection from infection, such as the maternal bacteria and the vernix caseosa, which is a potent inhibitor of escherichia coli.21 although the majority of the respondents always encourage breastfeeding, there are those that sometimes advise discarding the colostrum, the breast milk produced during the early days postpartum, as perceived to be dirty because of its yellowish color, which can be associated with pus. colostrum has a yellow to orange color because of its many substances that protect the baby from infections.22 the adherence to traditional birthing practices among the maranao tbas may be accounted for by the influence from their elderly family members and lack of formal training. the majority of the respondents have less compliance with the modern and ideal birthing interventions, thus increasing the risk of complications to both mother and newborn. this implies that health authorities must exert more effort in addressing this concern at the soonest possible time to decrease the incidence of maternal and neonatal morbidity and mortality. therefore, it is recommended that provision of culture - sensitive training to tbas and heightened health awareness programs to indigenous peoples be implemented to promote maternal and child health in marginalized communities. | this study determined the profile and birthing practices in both modern and traditional ways among maranao traditional birth attendants (tbas) in lanao del norte, philippines. it employed a descriptive research design. the respondents were 50 maranao tbas selected through the snowball sampling technique. a questionnaire was developed by the researchers to identify the respondents modern birthing practices utilizing the essential intrapartum and newborn care (einc) protocol. to determine their profile and traditional birthing practices, items from a previous study and the respondents personal claims were adapted. this study shows that maranao tbas have less compliance to the einc protocol and they often practice the traditional birthing interventions, thus increasing the risk of complications to both mother and newborn. |
one of the most important indicators for the mphe is the number of foreign students. in the analyzed period, the minimum number of foreign students in the higher education system, including medicine and pharmacy was recorded in 1975, while the maximum number of foreign students in mphe was reached in 1982, when 8177 students were enrolled, one year before the highest number of foreign students in romania : 16962. on average, there were 5739 foreign students enrolled in mphe meaning more than 52% of the foreign students coming for studies in romania were attending mphe. when calculating the proportion of the foreign students from mphe in the total number of foreign students from romania, an increasing and continuous trend is easily traceable for the 15 years analyzed, from as low as 34.2% in 1975 to as high as 74.9% in 1989. this trend is even more important after 1982, when the share of foreign students in the total students enlisted in the romanian higher education was starting to decrease. another important aspect to be emphasized is that the great majority of foreign students coming to mphe in romania were male students. on average 81.7% of foreign students entering mphe were male, consistent with the fact that in the entire higher education, 85.4% of the foreign students were male another important indicator is the total number of foreign freshmen. on average, there were 1438 foreign freshmen in mphe and 3219 in the entire higher education (almost 50% of all the freshmen between 19751989 were enrolled in mphe). most foreign freshmen were registered in the year 1977 (2110 students), while in the entire higher education there were 4985 freshmen in 1980. in the analyzed period, the years 1975, 1986 and 1987 were the only ones with under 1000 freshmen registered. the freshmen from mphe amounted to a maximum of 74% (1988) from all the registered freshmen in the higher education, and as low as 34% in 1981. for the situation of graduates the available data was for the period 19741988. on average, there were 1572 graduates in the higher education and 700 in mphe (up to 1249 in 1985 from a minimum of 61 graduates in 1975). in the romanian higher education there were 7 years with over 2000 foreign graduates (19811988) and six years with more than 1000 foreign graduates of mphe (1982 to 1987), which shows an almost perfect overlapping proving that mphe in the 1980s was the most important type of higher education from the point of view of foreign graduates. on average almost 5% of the total number of graduates of higher education in romania were foreign graduates, and 38% of them studied in mphe (maximum 64.1% in 1988, and no less than 17.7% in 1975). during 19821989, over 50% of graduates came from mphe. basically, in the 1980s the prestige of romanian higher education in terms of foreign graduates was provided by mphe. during communism, mphe functioned in the structure of two types of institutions : general and specific. among those specific there were two types : institutes of medicine and institutes of medicine and pharmacy (medical and pharmaceutical). in timisoara, and for a brief period also in iasi, there was only an institute of medicine. in bucharest, cluj - napoca, iasi and trgu mures functioned institutes of medicine and pharmacy. in addition to these institutions, in 1970 a faculty of general medicine (medicin general), later faculty of medicine, was established at the university of craiova. the university of craiova was the only institution that hosted medicine education outside specific institutions. let us mention that all these institutios were active not only in the most important higher education centers, but they also had a location important for the regional health care system, taking into account the role of dispersion and simultaneously, regional attraction of specialized staff. the most important institution for mphe in terms of attracting foreign students, was the institute of medicine and pharmacy from bucharest, which had enrolled an average of 1872 students, followed by the institute of medicine and pharmacy of cluj - napoca with its 1117 students, institute medicine and pharmacy of iai registering 1096 students, institute of medicine of timioara with 984 students and the faculty of medicine from the university of craiova with 650 students. in the period under review, the institute of medicine and pharmacy trgu mures did not attract foreign students except for two years in 1975 and 1976, when there were 83 and respectively, 236 foreign students recorded. the year 1981 was the most important in attracting foreign students for the institute of medicine and pharmacy of bucharest : there were 2640 foreign students registered. for the other institutions the corresponding indicator was also attained in the 1980s : in 1981 in cluj - napoca (1760 foreign students), in 1982 in iasi (1606), in 1983 in craiova (1037) and in 1985 in timisoara (1349). worth to point out is that between 1979 and 1985 over 2000 foreign students were registered each year in mphe in bucharest. as for the number of foreign freshmen, the institute of medicine and pharmacy from bucharest attracted on average 392 students (maximum 540 in 1984), cluj - napoca 303 (maximum 552 in 1978), iasi 287 (maximum 365 in 1979), craiova 198 (maximum 338 in 1983) and timisoara 196 (maximum 273 in 1981 and 1982). we can easily observe the general trend of the increased number of foreign students in all institutions from 1975 to the beginning of 1980, followed by a decrease and then a new increase for the last two years of communism. another interesting aspect is the number of foreign students attracted by mphe compared to those of the higher education centers in which they are based. thus, in bucharest, the most important centre of higher education in the country, 46.47% of foreign students were enrolled in mphe, lower than in timisoara which had 57.76%. the same value was 61.30% for iai, 65.51% for cluj - napoca, but much lower than for craiova, where foreign students were in an impressive share of 92.80%. the situation was not so much changed regarding the proportion of foreign freshmen in mphe from the total number of foreign freshmen : 41.34% in bucharest, 46.07% in timisoara, 61.73% in iai, 62.21% in cluj - napoca and again a big share in craiova, 90%. we also have a situation of the countries of origin for the foreign students in mphe, but only for the year 1988/1989. a top 10 of such countries is the following : 1155 foreign students came from greece, 966 from syria, 913 from israel, 480 from jordan, 466 from iran, 336 from germany (federal republic), 324 from sudan, 260 from lebanon, 171 from yemen and 141 from yugoslavia. like most of the examples mentioned, many other countries of origin for the foreign students were from the african continent and oil - rich arab countries, in the context of good political and economical cooperation with romania. among the faculties of mphe, faculty of medicine attracted more foreign students than the other faculties, followed by the faculty of dentistry and the faculty of pharmacy. for example, at the institute of medicine and pharmacy in bucharest the situation between 19751989 was the following : on average 1164 foreign students were enrolled in the faculty of medicine, 25 at the department of pediatrics, 602 in the faculty of dentistry, 89 in the faculty of pharmacy and 21 in the faculty of military medicine. for a close view on the statistics regarding the total number of foreign students at a faculty level, three tables were prepared, one for each of the most important faculties in mphe : medicine, dentistry and pharmacy. regarding the data in the last table, the following mentions need to be made : the faculty of medicine was merged with dentistry in timisoara starting with 1986 and also that under the faculty of medicine, different specializations could be covered (medicine, dentistry, pediatrics) like in craiova. in order to counter the changes in the structure while assessing in the long term the number of foreign students in mphe faculties, we have presented all the data, but made calculations for an average corresponding to 19751985, a period safe from statistical noise. the statistical data from this table and also from the followings, show almost in every centre of mphe an increase in the number of students in the last two years of communism, after the fall from 1987. when assessing the data from the table above, it is important, again, to note the changes in the structure of faculties of mphe : starting with 1986, the faculty of pharmacy and the faculty of dentistry were merged in bucharest and cluj - napoca, while in timisoara, as already mentioned, dentistry was merged with medicine, and in iasi with the faculty of pharmacy. these notes are important also for understanding the data in the following table : when re - focusing on the national level from the local level, the importance of mphe in attracting foreign students in the romanian higher education is easy to demonstrate. after 1948, the development of higher education was at all levels important, including attracting foreign students. the most successful type of higher education in this regard was mphe. regarding the main reasons which led to this situation we mention the low tuition fees and cost of living in romania, the need for currency of the romanian state, especially in the 1980s and the prestige of romanian higher education. maximum number of foreign students enrolled in higher education was achieved in 1981, 16962 foreign students and for mphe in 1982, 8177 foreign students. on average, there were 5739 foreign students enrolled in mphe meaning that more than 52% of the foreign students in romania were attending mphe, all based on a continuously increasing trend during the 15 years analysed. as for the gender representation, on average 81.7% of foreign students entering mhpe were male, consistent with the fact that in the entire higher education, 85.4% of the foreign students were male. on average, there were 1438 foreign freshmen in mphe and 3219 in the entire higher education (almost 50% of all the freshmen between 19751989 were enrolled in mphe), while 700 were graduates of mphe (1572 graduates were in the romanian higher education). on average almost 5% of the total number of graduates of higher education in romania were foreign graduates and 38% of them studied in mphe. the most important institution of mphe was the institute of medicine and pharmacy bucharest, both structurally and statistically. on average, bucharest attracted 1872 foreign students, followed by its counterparts in cluj - napoca (1117) and iasi (1096). in terms of attracting foreign students in the romanian higher education, craiova amounted an impressive proportion of over 90% of the enrolled foreign students in mphe, with important shares also for other centers of mphe. in bucharest, the most important higher education centre of the country, over 46% of foreign students were included in mphe, highlighting once again the leading role of this type of higher education in attracting foreign students in romania. mphe was the most important type of romanian higher education in terms of attraction of foreign students. as new documents will be available, new analyses on the issues already highlighted in this article will contribute to a better knowledge of the development of romanian higher education and mphe in the communist period. | after 1948 the romanian higher education entered a period of important developments, controlled by the communist regime, which meant thathigher educationinstitutions autonomy was severely obstructed, while politicalpurges affected the teaching staff and students alike. nevertheless, new types of higher education were introduced and new institutions of higher education and specializations were established. the number of students and graduates increased accordingly. also, after 1975, the number of foreign students in romanian higher education registered a significant increase mainly in medicine and pharmacy. more than half of foreign students attracted by the romanian higher education were studying medicine and pharmacy. many interesting aspects of this situation are presented in this article : reasons for this attraction, statistics of total number of students, number of freshmen, number of graduates and the contribution of each institution of medicine and pharmacy higher education in attracting the foreign students. |
computed tomographic angiography (cta) is a non - invasive mean of investigating isolated third nerve palsy to exclude intracranial aneurysm. however, third nerve palsy can be also associated with dural carotid cavernous fistulae (ccf) with anterograde inferior petrosal sinus drainage, which may occur without cta features of superior ophthalmic venous dilatation and orbito - ocular congestion. here, we present two cases missed by cta. a 68-year - old woman with a history of hypercholesterolemia and on statin therapy presented with progressive ptosis and diplopia over five days. physical examination showed left painful complete third nerve palsy without orbito - ocular congestive signs. cta showed a 2.5 mm left internal carotid artery (communicating segment) outpouch but did not show any other vascular pathology. digital subtraction angiography (dsa) confirmed the above finding as a left internal carotid artery infundibulum and also showed left dural carotid cavernous fistulae with drainage into the right inferior petrosal sinus. follow - up magnetic resonance angiography (mra) at 5 months showed persistent carotid - cavernous fistulae. similarly, 63-year - old woman with no medical comorbidity presented with ptosis and diplopia over five days. physical examination showed right painful partial third nerve palsy with mydriasis and without orbito - ocular congestive signs. dsa was carried out and found right dural ccf (figure 1a d). common causes of isolated third nerve palsies include diabetes mellitus and communicating segment internal carotid artery aneurysm. the above two cases illustrate that cta may not detect posterior - draining dural carotid cavernous fistulae when radiological signs of grossly engorged anterior cavernous sinus and a dilated superior ophthalmic vein are absent. in future, mra may act as a noninvasive diagnostic tool for these cta - negative posterior - draining dural carotid cavernous fistulae as illustrated by the first patient. embolization can also result in rapid and complete resolution of third nerve palsy in 88% of affected patients. figure 1digital subtraction angiography found right dural carotid cavernous fistulae fed by dural branches of bilateral internal carotid artery (ica) and drained through right inferior petrosal sinus. (a) right ica injection, ap projection ; (b) right ica injection, lateral projection ; (c) left ica injection, ap projection ; (d) left ica injection, lateral projection. digital subtraction angiography found right dural carotid cavernous fistulae fed by dural branches of bilateral internal carotid artery (ica) and drained through right inferior petrosal sinus. (a) right ica injection, ap projection ; (b) right ica injection, lateral projection ; (c) left ica injection, ap projection ; (d) left ica injection, lateral projection. | computed tomographic angiography (cta) is a well - established non - invasive investigation for this neurological presentation to exclude intracranial aneurysms. however, dural arteriovenous fistulae with anterograde venous drainage only can be missed by cta. here we reported two patients with painful complete third nerve palsy and dural carotid cavernous fistulae with anterograde venous drainage only missed by cta. the natural history and management option are discussed. in patients with persistent symptoms or without vasculopathic risk factors, magnetic resonance angiography (mra) or digital subtraction angiography (dsa) should be considered to exclude the diagnosis. |
the study was conducted at the department of ophthalmology of a medical college in north - east india between september 2012 and june 2014. approval from the institute 's ethical committee was obtained, and the study was carried out in accordance with the ethical standards of the 1964 declaration of helsinki. the inclusion criteria were as follows : (1) patients with unilateral csc, either acute or chronic ; and (2) patients who were willing to provide written informed consent. exclusion criteria were as follows : (1) patients with both acute and chronic csc together in one or both eyes ; (2) patients who had a history of using corticosteroids, steroid hormones in any form - systemic steroids (like oral / intravenous / intramuscular), topical eye drops, skin creams, intranasal / inhalational sprays, etc., in the past one month ; (3) any recent surgery or trauma ; (4) alcohol abuse or dependence ; (5) major depression ; and (6) other major eye or systemic diseases. the refractive status was determined with both automated and retinoscopic methods, using appropriate cycloplegia when needed. detailed slit - lamp biomicroscopy and indirect ophthalmoscopy were conducted after the pupils had been dilated. fundus fluorescein angiography (ffa) was carried out using a fundus camera visucam lite (carl zeiss meditec ag, jena, germany) and optical coherence tomography (oct) with spectral domain oct (model 500 ; cirrus hd - oct, carl zeiss meditec, dublin, ca, usa). the cases were classified as acute or chronic depending on the clinical, ffa and oct findings. an acute case of csc was defined as the first episode of csc that had symptom duration of less than three months with a well - circumscribed round or oval area of serous elevation of the neurosensory retina at the macular region. these acute cases also showed dye leakage either as a single leak or multiple leaks on ffa, with the leakage pattern being either the inkblot type or the smokestack type, as well as the presence of serous neurosensory retinal detachments either with or without rpe detachments on oct. chronic csc was defined as csc that had persisted for more than three months and showed clinical elevation of the neurosensory retina with fine rpe changes, like mottling and atrophy with pigmentation, revealing window defects with small leaks and mottled atrophic changes of rpe of a non - specific pattern on ffa and the presence of serous neurosensory retinal detachments with or without rpe detachments on oct. estimations of the 8:00 to 9:00 a.m. serum cortisol and testosterone levels were carried out in all the patients using a chemiluminescent immunoassay method (beckman coulter, fullerton, ca, usa ; supplied by beckman coulter india pvt. ltd., mumbai, india) ; 5 ml blood were collected in a plain vial and allowed to clot for 15 minutes at room temperature. the serum was separated by centrifuging the sample at the rate of 2,500 rpm for ten minutes. the serum was used for the analysis of cortisol and total testosterone levels in an automated access 2 immunoassay system (beckman coulter) as per the manufacturer 's protocol. proper standardization and internal quality control were ascertained as per these guidelines before the assays were conducted. the normal reference levels of serum cortisol and testosterone at our laboratory were determined as 6.70 to 22.60 g / dl and 1.75 to 7.81 ng / dl, respectively. an independent sample t - test was employed to identify any difference between the two groups. a partial correlation test was used to determine the difference in the levels of serum cortisol and testosterone by controlling for the effect of age and gender. a 5% level of significance an acute case of csc was defined as the first episode of csc that had symptom duration of less than three months with a well - circumscribed round or oval area of serous elevation of the neurosensory retina at the macular region. these acute cases also showed dye leakage either as a single leak or multiple leaks on ffa, with the leakage pattern being either the inkblot type or the smokestack type, as well as the presence of serous neurosensory retinal detachments either with or without rpe detachments on oct. chronic csc was defined as csc that had persisted for more than three months and showed clinical elevation of the neurosensory retina with fine rpe changes, like mottling and atrophy with pigmentation, revealing window defects with small leaks and mottled atrophic changes of rpe of a non - specific pattern on ffa and the presence of serous neurosensory retinal detachments with or without rpe detachments on oct. estimations of the 8:00 to 9:00 a.m. serum cortisol and testosterone levels were carried out in all the patients using a chemiluminescent immunoassay method (beckman coulter, fullerton, ca, usa ; supplied by beckman coulter india pvt. ltd., mumbai, india) ; 5 ml blood were collected in a plain vial and allowed to clot for 15 minutes at room temperature. the serum was separated by centrifuging the sample at the rate of 2,500 rpm for ten minutes. the serum was used for the analysis of cortisol and total testosterone levels in an automated access 2 immunoassay system (beckman coulter) as per the manufacturer 's protocol. proper standardization and internal quality control were ascertained as per these guidelines before the assays were conducted. the normal reference levels of serum cortisol and testosterone at our laboratory were determined as 6.70 to 22.60 g / dl and 1.75 to 7.81 ng / dl, respectively. an independent sample t - test was employed to identify any difference between the two groups. a partial correlation test was used to determine the difference in the levels of serum cortisol and testosterone by controlling for the effect of age and gender. a 5% level of significance a summary of the characteristics of the patients along with their serum cortisol and testosterone levels is given in table 1. the mean age was 42.43 6.37 years (range, 32 to 56 years). the mean 8:00 to 9:00 a.m. serum cortisol level was 12.61 4.74 g / dl (range, 6.58 to 27.42 g / dl). the mean serum testosterone level was 5.88 1.57 ng / dl (range, 2.81 to 9.94 ng / dl). the mean visual acuity was 20 / 65.07 40.56 (range, 20 / 25 to 20 / 200). there was no statistically significant difference in the mean levels of serum cortisol and testosterone between the acute and chronic cases (p > 0.05), but there was a statistically significant difference in the mean presenting visual acuity in the two groups (p < 0.05). no statistically significant difference in the levels of these hormones could be found by controlling for the effect of age (p = 0.937 for serum cortisol and p = 0.545 for testosterone) and gender (p = 0.963 for serum cortisol and p = 0.491 for testosterone) using a partial correlation test. clinically, acute cases revealed a well - circumscribed round or oval area of serous elevation of neurosensory retina at the macular region. chronic cases showed a mild elevation of the neurosensory retina with fine rpe changes, like mottling and atrophy with pigmentation. ffa revealed leakage of dye either as a single leak or multiple leaks in acute csc. chronic cases showed window defects with small leaks and mottled atrophic changes of the rpe with a nonspecific pattern (fig. csc is an idiopathic disease characterized by serous detachment of the neurosensory retina in the macular region secondary to a focal retinal pigment epithelial defect. risk factors are type a personality, corticosteroid use in various forms, age, male gender, increased endogenous cortisol production, systemic lupus erythematosus, pregnancy, antibiotic use, alcohol use, allergic respiratory disease, untreated hypertension, psychopharmacologic medication, organ transplantation, hemodialisis, and cortisol - producing tumors. it is usually self - limited with spontaneous resolution at four to six months, but a few cases may progress to chronic disease with prolonged serous macular detachment. csc is said to predominantly affect young and middle - aged males between 20 and 50 years, and its incidence declines with advancing age. however, there are reports of csc occurring in patients 60 years or older. in our study, the age of patients ranged from 32 to 56 years (mean, 42.43 6.37 years). the treatment of csc is not established uniformly. in a retrospective follow - up study, gilbert even centuries after von graefe described recurrent serous detachment of the macula as " recurrent central retinitis " in 1866, the etiology of this condition continues to elude clinicians despite active research. determined the endogenous cortisol levels in urine and plasma samples in 30 patients with acute csc and compared them with 30 age and sex matched controls. they found that the mean plasma and urine cortisol levels were significantly higher in patients with acute csc compared to age - matched controls. similarly, kapetanios. evaluated the levels of endogenous cortisol in 16 patients with acute csc and compared them with the age and sex matched control group. however, chalisgaonkar. did not find a precise correlation of the serum cortisol with csc. similarly, tufan. could not identify any correlation of the serum cortisol with chronic csc. from these studies, it can be inferred that there is an inconsistent relationship between the levels of serum cortisol and csc. in our study, 30 patients with either acute or chronic csc were evaluated. there were 17 cases with acute csc (56.7%) and 13 cases with chronic csc (43.3%). all except case no. 6 (96.67%) had serum cortisol levels within the normal range.. identified corticosteroid use as a risk factor associated with csc that was distinct from psychopharmacologic medication use and hypertension in their retrospective study of 230 consecutive patients with csc. similarly, in an observational case series of 24 patients, haimovici. reported that the serum testosterone levels were within the normal range in 23 of their 24 patients. were the first to estimate the serum testosterone levels in patients suffering from csc and compare them with age and sex matched controls. the mean serum levels of testosterone were observed to be within the normal range in both csc patients and controls. however, they found 32% of csc patients and 18% of controls to have lower than normal levels of testosterone. in their study, tufan. reported serum testosterone levels within the normal range in patients with chronic csc they concluded that the association between these hormones and chronic csc might be weak. in our study, all cases (100%) had serum testosterone levels in the normal range. we carried out the present study because no study thus far has revealed a difference in the levels of serum cortisol and testosterone in acute and chronic csc. if a difference is found, it might shed some further light on the etiopathogenesis of csc and explain why some patients with csc have recurrences whereas others do not. however, we did not find any statistically significant difference in the levels of serum cortisol and testosterone in acute and chronic csc, even after controlling for the effects of age and gender. in conclusion, it may be inferred from our study that there is unlikely to be any statistically significant difference in the mean levels of serum cortisol and testosterone between the acute and chronic cases of csc, but there may be a statistically significant difference in the mean presenting visual acuity in the two groups. | purposeto compare the levels of serum cortisol and testosterone in acute and chronic central serous chorio - retinopathy (csc).methodsserum cortisol and testosterone levels in 30 patients with either acute or chronic csc were evaluated using chemiluminescent immunoassay.resultsthe mean age was 42.43 6.37 years (range, 32 to 56 years). the mean 8:00 to 9.00 a.m. serum cortisol level was 12.61 4.74 g / dl (range, 6.58 to 27.42 g / dl). the mean serum testosterone level was 5.88 1.57 ng / dl (range, 2.81 to 9.94 ng / dl). the mean visual acuity was 20 / 65.07 40.56 (range, 20 / 25 to 20 / 200). there was no statistically significant difference in the mean levels of serum cortisol and testosterone between the acute and chronic cases (p > 0.05), but there was a statistically significant difference in the mean presenting visual acuity in the two groups (p < 0.05).conclusionsall except one patient in the acute group had normal levels of serum cortisol. testosterone levels were within the normal range in both the acute and chronic cases of csc. there is unlikely to be any statistically significant difference in the mean levels of serum cortisol and testosterone between the acute and chronic cases, but there may be a statistically significant difference in the mean presenting visual acuity in these groups. |
the occurrence of two unprovoked seizures more than 24 hours apart could indicate the presence of an epileptic disorder. most cases of epilepsy are managed efficiently by medication, and afflicted children have normal iq and are expected to have a normal life. however, these children need to be carefully monitored for psychopathology and learning disability, as both of these are more common in epileptic children than in the general population[1, 2 ]. the prevalence of depression in the pediatric population according to the isle of wight study was 0.2% in 10 year olds and 2% in 14 year olds. more recent studies have reported higher rates of 1 - 5 percent among children and adolescents. the prevalence of depression among children with epilepsy in different worldwide studies varies from 23% to 33%[69 ]. psychosocial risk factors of depression in epilepsy include the fear of seizure, perceived stigma, learned helplessness and pessimistic attribution, and decreased social support. biological risk factors include family history of mood disorder, left sided focus and focus in temporal or frontal lobe. in recent years, diagnosis of depression has changed due to the refinements in the diagnostic criteria of depression in icd-10 and dsm - iv. according to these criteria symptoms of depression should persist at least for 2 weeks, with core symptoms being present during most days. however many researchers have used various screening tools and rating scales to diagnose and quantify depression. the aim of this study was to evaluate the prevalence of depression in epileptic children and adolescents by reviewing the existing literature. we also compared the findings of those studies indicating an association between depression in epileptic children and their gender, age, type of epilepsy, duration of epilepsy, age of onset and the number of antiepileptic drugs (aed) used. from a clinical perspective, we attempted to highlight the potential risk factors for depression in epileptic children, with a view to increasing the awareness of clinicians, and improving the diagnosis and management of depression among these patients. although there are a number of comprehensive review articles on the subject, most of them date back to at least 6 years ago. on the other hand, the changes in the diagnostic criteria of depression since the introduction of icd-10 and dsm - iv in the mid-1990s, and the introduction of new generations of aeds within the past 15 years have had a considerable impact on the clinical presentation, diagnosis and management of depression in epileptic children. the study therefore has intended to review the original articles published in the last 15 years in order to reflect recent changes in the prevalence of depression among children with epilepsy. a search of medline, nlm gateway, ovid and embase was carried out using the keywords epilepsy, epileptic, depression, depress, child, children, adolescent, psychiatric comorbidity and seizure. the original articles which studied only epileptic children and adolescents, evaluated depression as the comorbidity of epilepsy, and described demographic and epilepsy - related variables associated with depression in epilepsy, were included in this study. however, 62 studies were excluded as they focused on depression as comorbidity in adults. of the 38 studies included, those mentioning depression as only a component of the affective or emotional comorbidity of epilepsy - rather than a distinct condition - were excluded. of the remaining 20 articles, a further 9 were excluded due to being review articles and meta - analyses, leaving 11 articles for final review. the references of the initially qualifying 38 articles were also reviewed in order to find further relevant studies, yielding no new results. the main 11 articles included in this study reported data on 1095 epileptic children and adolescents aged 4 - 19 years. all studies were designed as cross - sectional studies, however they were characterized by considerable variability in the population setting and sample sizes (max = 173 ; min = 35). the number of female and male participants in most studies to be almost similar (fig 1). researchers assessed the children by standard measures of depression in child and adolescent according to the diagnostic and statistical manual of mental disorders (dsm) or international classification of diseases (icd) criteria. the results are organized into two main categories : firstly the prevalence of depression, and secondly, the factors associated with the development of depression in epilepsy ; bearing in mind the interdependence between the two. prevalence of depression among children with epilepsy : review of the papers showed that the prevalence of depression among epileptic children and adolescents aged 4 - 19 years, ranges from 5.2% to 39.6%. the rate of depression in referral centers for epilepsy has been extremely higher in one study. they showed more than 70% of all referred epileptic children have suffered from a psychiatric disorder, with the most common being depression at the rate of 36.4%. another study showed that most of the depressed children had co - morbidities of disruptive (28%) or anxiety (3.5%) disorders. children with co - morbid affective / anxiety or disruptive disorders were more likely to suffer from depression than children with only mood disorders. suicidal ideation among epileptic patients was 20% and 12 times more common in patients with co - morbid anxiety / depressive or disruptive disorders. interestingly, the rate of depression in epileptic children with or without suicidal ideation was the same. one of the remarkable findings of this review was the results of turky study in 2007. they showed that according to the results of parent - report measures, 39.6% of children with epilepsy were depressed ; while based on self - rating scales this rate was 23.1% (fig. sample size in 11 studies the number of depressed cases among epileptic patients characteristics of the included papers demographic and epilepsy related factors and depression prevalence : regarding demographic factors of samples, only two studies found a correlation between gender and the rate of depression[10, 11 ]. considering the age as a risk factor for developing depression, three studies have stated the tendency to developing depression is higher in epileptic adolescents and older age groups[9, 10, 12 ]. epilepsy - related factors including seizure duration, age of onset, type of epilepsy, and the number of aeds used by epileptic children were studied by reviewing the eleven studies. only two studies stated longer duration of epilepsy to be a likely correlated factor for developing depression in children[9, 13 ]. four studies in this review showed that focal epilepsy was more significantly associated with depression than generalized epilepsy[10, 1214 ]. the association between the development of depression in epileptic children and polytherapy with anti - epileptic drugs was found in three studies[9, 13, 15 ]. clinical investigations and other research studies during the last two decades have revealed that depression is one of the most frequent psychopathologies among epileptic individuals. moreover, a number of risk factors and comorbid disorders have been found that may impact the rate of depression in epileptic children. the results of the current study show that the prevalence of depression among epileptic children and adolescents ranges from 5.2% to 39.6%. caplan stated that epileptic children have comorbid psychiatric problems, and the prevalence of comorbid depression and disruptive disorders in these patients is 28.5%. the wide range of prevalence and inconsistency of the results may be related to several factors. firstly, different methods for assessing depression have been used, e.g. structured or semi - structured interviews, self report scales such as cdi, or parent rated measures such as sdq or disc - iv (table 1). in one study, turky reported the rate of depression according to parent - rated instruments to be 39.6%, whereas in the self report assessments for the same sample it was 23%. this discrepancy could reflect the possibility that some children may not be fully aware of the impact of seizure on their lives. secondly, different sample sizes - ranging from 35 in some studies[9, 16 ] to 173 in another - and dissimilar designs of studies, as well as various methods of recruiting of samples could affect the results. lastly, the time of the study can be important, as the prevalence of depression has increased in parallel with the recent changes in diagnostic criteria of icd-10 and dms - iv (fig. e.g. age and gender of samples, caplan indicated that there has been a tendency for epileptic patients with affective and anxiety disorders to be female (63% vs 43%), however, the correlation was not significant. turky showed that female gender was an independent predictor for depression in epileptic subjects (73.7% vs 26.3%, p=0.04). although the literature suggests that adolescent girls are athigher risk of depression than boys in general population, this review does not find such an association to be consistent in epileptic children. some research has shown that psychosocial and behavioral problems are more likely in epileptic girls than boys, especially in adolescents. this seems to be accounted for by girls being more realistic than boys, and boys being usually more optimistic. in adolescents depression and emotional disorders measures are mostly self - rated and based on own perception and self - concept of participants. the prevalence of depression in 11 studies on the whole, this review could not find a correlation between the rate of depression and gender in epileptic individuals. with regard to age as a risk factor for depression in epileptic children, caplan stated that in epileptic children with anxiety and affective disorders, those with depression were in the older age group ; however the relation was not significant. in oguz study depression was significantly more frequent in 12 - 18 year olds than the 9 - 11 year old group (p<0.05). thome - souze showed that depression has been diagnosed in 75% of epileptic adolescents (13 - 17 years) compared to 25% in epileptic children aged < 6 years (p<0.0001). other studies in this review did not confirm age as a risk factor for depression. differences between the results of these eleven studies may be related to the use of various measures for depression screening by different researchers. some studies measured depression using a parent report scale, especially for younger groups. with depressive disorders generally categorized as internalizing conditions, it is likely that parents are not aware of the depressive nature of their children 's symptoms. this suggests that children are more accurate reporters of internalizing problems, including depression, than parents. seizure - related factors including seizure duration, type of epilepsy, age of onset, and the number of aeds used by epileptic children were evaluated in all 11 studies, and different results emerged. considering the duration of epilepsy, oguz indicated that in epileptic children with seizure duration longer than 3 years, depression is more likely to develop (p<0.05). a similar finding by roeder showed that longer duration of epilepsy increased the severity of depressive symptoms. in contrast, jones indicated that children with recent onset epilepsy presented a higher rate of depressive disorders compared to controls (22.6% vs 4%, p=0.01). some of children with epilepsy (45%) showed some degrees of psychiatric disorders before their first seizure, of which 20.8% had depression. the authors stated that the rate of depression did not differ before and after the presence of seizure, suggesting underlying factors other than chronicity of epilepsy or aeds may increase the risk of psychopathology. in our review, the association of depression with duration of epilepsy was found to be inconsistent. several factors including different rating scales and diagnostic measures, different sample sizes and different study designs may have contributed to this discrepancy. rather uniquely among reviewed studies, oguz divided the cases into two groups according to duration of epilepsy (less than 3 years, and more than 3years), which probably influenced the results and showed a higher rate of depression in the longer duration group. we could not find any correlation between developing depression and age of onset of seizures in this review. however, studies on population based sample of epileptic children showed that children with early onset epilepsy (< 4 years) are more likely to have behavioral problems (p<0.001). these children did not develope depressive symptoms and their behavioral problems can be explained by long term use of anti - epileptic drugs. regarding the association of depression with the type of seizure, roeder showed that diagnosis of focal seizures was correlated with severe depressive symptoms (p<0.05) in 96 participants. three other studies stated depression and other psychiatric disorders to be more frequent in children with focal seizure[10, 12, 14 ]. however, the whole results of our review did not support this association, which may reflect different sample sizes and different ages of participants, as well as various methods of measuring depression used by the researchers. finally, a few studies showed the association between depression and the number of antiepileptic drugs. roeder stated that greater number of aeds was independently associated with severe symptoms of depression, suggesting the number of aeds to be a risk factor for undetected symptoms of depression. oguz stated that depression was significantly higher in patients receiving more than one aed, compared to monotherpay (p<0.05). there are numerous studies in the literature investigating the effect of aeds on cognitive function or behavior in elipleptic children, although the results are quite contradictory. establishing an association between aeds and the symptoms of depression in epileptic children was found to be fraught with difficulties ; due to side effects of aeds immitating the symptoms of depression or behavioral problems, e.g. sleep problems, change in appetite, concentration difficulties or psychomotor retardation. plioplys stated that the depressogenic effect of aeds can not explain development of depression in children per se ; suggesting this effect to be related to the side effects of individual drugs. more specifically, brent showed an association between depression and phenobarbital compared to carbamazepine, and demosntrated a much higher prevalence of major depression (40% vs 4%) in epileptic children treated with phenobarbital. overall, it seems that the effect of aeds on the development of depression needs further investigation. in this study we reviewed the original articles published in the past 15 years on the prevalence of depression in epileptic children and adolescents, and its association with demographic and seizure variables. our study shows that depression continues to be very common in epileptic children and adolescents, indicating that pediatricians and other physicians working with epileptic children should have a high index of suspicion for this comorbid condition. clearly, better preventive strategies, early diagnosis and more comprehensive packages of care for depression in children with epilepsy will enable them to have a better quality of life. the results, on the whole, do not support the presence of an association between depression and age, gender, duration of epilepsy, type of epilepsy, time of onset and the number of aeds used in children and adolescents, although a few studies found a significant association for depression and some of the above mentioned factors. in the last decade newer generation of aeds with differing side effect profiles, have been used extensively in children. some of these new aeds are now used as anti - depressant or anti - anxiety agents in adults but it is not clear how they affect emotional state of epileptic children. further studies, in particular randomized clinical trials focusing on particular new aeds are needed to clarify the ambiguities arising from polypharmacy. uncertainties due to the changing pattern of coping strategies in children, especially during the pre - pubertal and early pubertal period, could be similarly elucidated by studying specific age sub - groups. | objectivethe paper aims to study the prevalence of depression in epileptic children and adolescents by reviewing the existing literature, looking for any association between depression in these children and their demographic or seizure related factors to highlight the potential risk factors for depression in epileptic children.methodsa search of medline, nlm gateway, ovid and embase was carried out to study original english language articles published during the last 15 years, focusing on only epileptic children and adolescents, studying of depression as comorbidity of epilepsy, and describing demographic and epilepsy - related factors associated with depression.findingsthe 11 articles included in this study have reported data on 1095 epileptic children aged 4 - 19 years old and showed that the prevalence of depression has continued to be very common in epileptic children and adolescents, ranged from 5.2% to 39.6%. on the whole, the findings did not support the presence of an association between depression and demographic or seizure variables in children.conclusionpediatricians and other physicians working with epileptic children should have a high index of suspicion for depression as a comorbid condition in children with epilepsy. early diagnosis and more comprehensive packages of care for depression in epileptic children will enable them to have a better quality of life. |
it is well - established that achievement of high bond strength to dentin is dependent on complete penetration of resin into spaces around the collagen fibrils in demineralized dentin. in acid - etched dentin, following complete dissolution of the minerals and loss of structural support of the fibrils, interfibrillar spaces are replaced with water in a full expansion state to facilitate resin penetration and hybrid layer formation known as wet - bonding technique. nevertheless, this technique is sensitive and has some disadvantages. the lack of practical criteria to manage the optimal degree of wetness on dentin substrate complicates the wet bonding for clinicians. as a result, it is applied differently among operators and in instructions of the manufacturer so that over - wetting or over - drying may occur instead of ideal moisture on the dentin. excess water can not be easily evaporated due to low vapor pressure and presence of hema contained in many adhesives, retaining water in the bonding site ; phase separation of resin components may take place. this residual water is capable of diluting the concentration of adhesive monomers, preventing monomers diffusion to the full depth of the demineralized dentin and adequate polymerization of the monomers inside the collagen network. subsequently, the formed porous hybrid layer is more susceptible to water degradation over time. the adverse effects of water on the adhesive interface can be minimized when the etched dentin is kept in a dry state. dry bonding may be obtained during air drying of the cavity after rinsing by clinician to ensure the frosted etched appearance of the enamel. however, air drying the demineralized dentin leads to collapsed collagen network. as a result the formed sub - optimal and porous hybrid layer may account for immediate low bond strength and long - term degradation of resin - dentin bond. although it seems that dried etched dentin is easily obtained, in clinical situation, air blowing of the smear layer and smear plugs - free dentin for water evaporation leads to increased outward fluid flowing from the pulp. different studies showed the effectiveness of oxalate solution in blocking the orifice of dentinal tubules. therefore, it can reduce the outward flow of dentinal fluid during bonding procedure. in this way, simultaneous tubular occlusion and possible maintenance of the collagen matrix stability in the absence of water can be a beneficial approach to provide high and stable dentin bonding. ethylene - diamine tetra acetic acid (edta) is a molecule containing four carboxylic acids that function as a chelating agent at neutral ph. some studies reported a favorable effect of edta - conditioning to provide sufficient dentin bond strength. it is capable of selectively removing hydroxyapatite, preserving the structural stability of the collagen matrix. this stability is attributed to lack of alteration of the native fibrillar structure of the collagen during dissolving the mineral phase of the dentin. hence, habelitz. suggested that the edta - conditioned dentin may be less affected by air drying due to the presence the unaltered collagen containing most of their intrafibrillar mineral. based on the above - mentioned points, the interfering effect of water with bonding performance of the simplified etch - and - rinse (one - bottle) adhesives may be prevented by the combination of edta - conditioning and occluding effect of oxalate desensitizers during dry bonding without compromising bonding efficacy. therefore, the aim of this study was to evaluate whether this combination produces the adhesive bond strength similar to that made using conventional wet bonding on acid - etched dentin. one - hundred and twenty extracted sound human third molars were used in the current study. the teeth were stored in 1% chloramines t solution for 2 weeks, and then in distilled water at 4c before use. after removing the roots, the midcoronal dentin surfaces were exposed by removing the occlusal enamel with a diamond saw (letiz, 1600, germany) under running water. the flat dentin surfaces were polished with silicon carbide paper to standardize the smear layer. the specimens were randomly divided into 12 groups of 10 teeth each. in the first four groups, one - step plus (os) was used and optibond solo plus (op) was applied in the other four groups. in the remaining four groups, adper single bond (sb) the bonding procedures were performed as follows : in the control groups 1, 5, and 9 (wet / acid), after phosphoric acid etching for 15 s and rinsing, the dentin surfaces were gently air dried for 5 s while leaving the moist dentin. then, os, op, and sb were applied according to the manufacturer 's instructions, respectively [table 1 ]. materials used in the current study in the experimental groups 2, 6, and 10 (wet / edta), the dentin surfaces were conditioned with 0.1 m edta solution (ph 7.4, merck co., germany) for 60 s instead of using the phosphoric acid etching. the remaining bonding procedures were performed as in respective control groups. in the experimental groups 3, 7, and 11 (dry / edta), edta conditioning and bonding procedures were performed similar to the previous respective groups, with the exception of dry bonding. after rinsing, the conditioned surfaces were extensively air dried for 30 s with oil - free compressed air. in control, wet / edta, and dry / edta groups, we had removed the pulp tissue prior to preparing the specimens for bonding procedure. in the experimental groups 4, 8, and 12 (dry / edta + ox), the bonding procedures were performed similarly to the previous respective groups, only an ox (bisblock, bisco) was added to bonding procedures. after edta conditioning and rinsing, ox was applied and dwelled onto the dentin surfaces for 30 s ; then, the surfaces were rinsed for 60 s and dry bonding was performed. after curing the adhesives for 20 s at 600 mw / cm with a light curing unit (vip junior, bisco, schaumburg, il, usa), a resin composite (z250) was placed on the cured adhesive using a cylindrical split mold with a height of 2.5 mm and surface diameter of 2 mm. two increments of 1 mm and 1.5 mm were applied and separately cured for 40 s. after 24 h water storage and thermocycling (1000 times), bond strength test was performed. shear bond strength (sbs) was measured with a universal testing machine (instron z020, zwick, roell, germany). a knife - edge shearing rod at a cross head speed of 1 mm / min was applied to load the specimens until fracture and bond strength in mpa was recorded. the data were analyzed using two - way analysis of variance (anova) and tukey 's honestly significant differences (hsd) hsd post - hoc tests for pair - wise comparisons at a significance level of 0.05. after testing, the fracture modes were evaluated under a stereomicroscope (ziess) at 10 and classified according to the predominant mode of fractures as adhesive, cohesive in dentin, cohesive in composite and mixed, a combination of adhesive and cohesive [table 2 ]. the mean bond strength and standard deviations of the 12 groups are presented in table 2, and the results of two - way anova are shown in table 3. the use of edta instead of phosphoric acid did not alter sbs of the three used adhesives. when dry bonding by edta, os showed significantly lower sbs than those of wet bonding by phosphoric acid or edta (p 0.05). sbs of os in dry bonding with or without ox was similar, being significantly lower than wet bonding with phosphoric acid etching (p 0.05). the pair - wise comparisons of four bonding conditions for each adhesive (os and op) are summarized in table 4. results of pair - wise comparisons of four bonding conditions was performed by tukey hsd test for each of two adhesives fracture analysis revealed that most of the fractures of groups 3 and 4 (os in dry bonding with edta conditioning with or without ox) and group 8 (op with ox) were adhesive mode. in other groups, in the current study, three one - bottle adhesives with different solvent content (acetone and water / ethanol) and ph were used under four bonding conditions. edta - conditioning and acid etching revealed similar bond strengths under wet bonding for these adhesives. the thin edta - demineralized collagen matrix contains intrafibrillar mineral, preserving its spongy and stable state, and hence may improve resin infiltration. the resultant more homogenous hybrid layer may be strong and could produce a high bond strength due to possible chemical interaction between acidic / functional monomers with calcium in residual mineral within the collagen fibrils. based on the mentioned properties of edta - conditioned dentin, it was speculated that this dentin is less influenced by dehydration. in the current study, this hypothesis was supported when op and sb were bonded to dried edta - conditioned dentin, but not for os. acetone - based adhesives are more sensitive to an accurate wet bonding technique than ethanol - based ones and require greater surface wetness due to the high water - chaser effect of acetone. ethanol / water - based adhesives possess the capability of promoting re - expansion of dried collapsed matrix during the infiltration of solvated resin monomers. however, a substantial decrease of bond strength to acid - etched dentin was reported for two ethanol / water based adhesives (excite, op) following air drying for 10 s. reis. suggested that fluid flowing from the retained moist pulp tissue during dry bonding may account for insignificant reduction of bond strength of sb compared to wet bonding. more severe dry bonding condition was performed and bond strength was significantly decreased. in the current study, the pulp tissue was removed prior to bonding procedures (except for groups with ox) similar to the latter study to eliminate the interfering effect of water permeation within the tubules ; however, the bond strength of sb and op was not altered under dry bonding on edta - conditioned dentin. this finding might indicate more stability of the dried dentin following edta - conditioning compared to acid etching. in clinical situations, controlling the level of moisture may practically be more difficult and non - uniform wetness may exist on different regions of dentin surface. furthermore, re - wetting capability of naturally moisture dentin may mitigate the effects of dry and wet bonding. hence, the application of ox may be beneficial to occlude dentinal tubules, optimizing different wetness conditions ; in the current study, its compatibility with the adhesives used in dry bonding with edta was evaluated. the reduced permeability of acid - etched dentin was the result of precipitating calcium oxalate crystals below the demineralized dentin. thus, ox did not compromise the bond strength of relatively neutral etch - and - rinse adhesives (such as sb and one - step). however, in two recent studies, ox application decreased bond strength of sb, one - step and scotchbond multi - purpose, but it had no effect on prime and bond nt. in literature, the name of commercial products (all parts of each product name) is commonly started with capital letters. nt associated with prime and bond is the name of one commercial product. we corrected the products names in whole of the article text. according to the results of the current study, ox had an adverse effect on bonding efficacy of op that may be due to low ph of this adhesive. the higher number of adhesive fractures together with a decrease in bond strength in groups 3, 4 and 8 may have been caused by the lower bonding effectiveness of these bonding conditions. therefore, only sb with a relatively high ph and the ethanol / water content exhibited the compatibility with the combination of ox treatment on the edta - conditioned dentin under dry bonding. dry bonding associated to ox pre - treatment may enhance the removal of solvents and residual water after the application of the adhesive, and formation of resin tags. however, dry bonding may lead to collapsed collagen matrix in the etched dentin. based on our results, edta - conditioning possibly improves resin penetration in dry bonding condition for the ethanol / water adhesive, resulting in less fibrils exposure. nevertheless, scanning electron microscopic evaluations are needed to explain these results and actual interaction of different adhesive systems on ox treated dentin in dry and wet conditions. moreover, edta treatment may extract and inactivate matrix metalloproteinase 's involved in degradation of the exposed collagens. these long - term effects can be studied in laboratory tests with more simulating in vivo situations such as using a positive pulpal pressure and the presence of fluid flowing. nevertheless, the need for separate enamel etching, difficult control of edta solution only on the dentin surfaces, and the relatively long time (60 s) needed for its application might be disadvantages in clinical practice. based on the results of this in vitro study, among the three adhesives used, only an ethanol / water based adhesive with a relatively low acidity could benefit from the association of ox pretreatment and edta - conditioning, in a relatively severe dry bonding technique. | background : elimination of water entrapment in hybrid layer during bonding procedure would increase bonding durability.aims:this study evaluated the effect of oxalate desensitizer (ox) pretreatment on bond strength of three one - bottle adhesives to ethylene - diamine tetra acetic acid (edta)-conditioned dentin under dry bonding.materials and methods : three adhesive systems, one - step plus (os), optibond solo plus (op) and adper single bond (sb) were bonded on dentin surfaces under four bonding conditions : (1) wet - bonding on acid - etched dentin, (2) wet bonding on edta - conditioned dentin, (3) dry bonding on edta - conditioned dentin, (4) dry bonding associated with ox on the edta - conditioned dentin. after storage and thermo cycling, shear bond strength test was performed. data were analyzed using two - way analysis of variance and tukey tests.results:wet bonding with edta or acid etching showed similar bond strength for test adhesives. dry bonding with edta significantly decreased the bond strength of os, but it had no effect on the bonding of op and sb. ox application in the forth bonding condition, in comparison with the third condition, had a negative effect on the bond strength of op, but not influence on os and sb.conclusions:the use of an ox on edta - conditioned dentin compromised the bonding efficacy of os and op under dry bonding but compatible for sb. |
skydiving, sport parachuting from aircraft, engages more than 800,000 participants in over one hundred countries who make more than 6 million jumps per year. skydiving can be viewed as an extreme sport, by being associated with a risk of death or serious injury. skydiving activities are dependent on rules and regulations issued by authorities, but it is also suggested that the policing role of more experienced skydivers sets limits of risk behavior to an even higher degree than formal regulations. the risks associated with modern skydiving have not been satisfactorily described in the scientific literature. because of lack of unified reporting systems and differences in definitions of injury, the reporting and comparisons of incidents and injuries are hard to make. injury rates of 170 per 100,000 jumps with an accompanying hospital admission rate of 18 per 100,000 jumps have been reported from the united states and similar rates have been reported from european countries [57 ]. in sweden, an injury rate of 48 per 100,000 jumps has been reported. most countries in the world do not have reliable figures on the epidemiology of incidents and injuries. the international parachuting commission (ipc) has identified four member countries (france, finland, norway, and sweden) which collect reliable and valid data as the countries have compulsory national routines for reporting of injury events. the ipc has a reporting system for injuries and fatal incidents, but severe problems in acquiring reliable data have made it necessary to identify elements that may influence the reporting culture in the different member states ; that is, what makes the individual skydiver choose to abide to formal rules connected to reporting of incidents and injuries. studies of swedish skydiving have used epidemiological designs to describe fatal and nonfatal injury events [8, 9 ]. a report is compulsory for an incident / injury that leads to a health care visit. the validity of the nonfatal data may be questioned since the performance of the compulsory swedish system has been reported as having a sensitivity of 0.37 and a specificity of 0.91. reasons for this grave underreporting of injuries, several of which were serious or even life threatening, are not known. social or cultural factors that may play a role are difficult to assess through epidemiological quantitative designs. a qualitative interview study may provide grounds for understanding and clarifying why individuals, despite the compulsory reporting obligations, choose not to report adverse events. a study from wales found culture, or more specifically, reporting culture among surgeons to be one explanatory variable for a discrepancy between surgeons and theatre nurses. approximately 55% of surgeons and 91.5% of theatre nurses report all or more than 50% of mucocutaneous and percutaneous injuries occurring in operating theatres. the cumbersome administrative procedure, the attitude, personal characteristics of the surgeon, and lack of feedback were given as important reasons for not reporting incidents. according to roberts and rousseau, can management attitudes and institutional climate greatly influence the success or failure of reporting efforts in high reliability organizations. in high - reliability theory, incident reporting / response systems are important instruments to effectively synthesize and share information with the relevant people across an organization so that appropriate action can be made to prevent or reduce the risk of accidents and disasters. this is also the basic idea for reporting incident and injury events within the sport of skydiving. for instance, a reported incident related to technical failure of a specific piece of the parachute equipment may lead to modification or market withdrawal. although most skydivers are pursuing their air sport as a leisure time activity and not as a job, individual, organizational, subcultural (e.g., reporting culture), and social aspects may influence the motivation and other incentives to report incidents and injuries. to date, no studies have given voice or studied how skydivers describe events leading to incidents and injury, or how this relates to injury risks and injury reporting. the objective of the present study was to illuminate the experience of injuries and the process of injury reporting within the swedish skydiving culture. this study is based on a qualitative approach, where data was collected in narrative interviews that were subsequently analyzed with content analysis. a qualitative study can provide a scientific ground to interpret phenomena on the basis of the meanings the studied group of people assign them. inclusion of respondents was made through a convenience sampling procedure ; that is, respondents readily at hand and willing to participate in the study were interviewed. respondents were recruited through a personal contact on three different skydiving drop zones in sweden. efforts were made to include respondents from a broad spectrum of skydivers regarding age, sex, and experience of skydiving. twenty people were invited to the study ; three chose not to participate because of time constraints. the total sample of 17 respondents consisted of six women and 11 men between the ages of 22 and 44 (median = 29). they had been skydiving between one and 25 years (median = 6) and had made between 14 and 3400 jumps (median = 750). each interview began with a short presentation of the study, followed by a broad question could you please tell me about events where you have been injured or have nearly injured yourself while skydiving ? follow - up questions, if necessary, were asked in accordance with an interview guide (table 1). interviews were digitally recorded and lasted between half an hour and two hours and were later transcribed verbatim. the interviews were conducted in places chosen by the respondents, either at drop zones, at respondents ' home, in cafs, or at their work. the text data underwent a qualitative content analysis where an attempt was made to determine and interpret both the manifest (what is said) and the latent content (what it means) of the text, referred to as categories and/or themes [15, 17 ]. the description of the analytic procedure is simplified as the three steps that were intertwined and overlapping. the first step. to achieve an overall understanding of the text, each transcript along with the reading, meaning units were identified and given a temporary code in the body of the text. the coding was used to more easily link and sort text passages connected to each other. the second step. during the process of coding and sorting the meaning units, three categories, the scheme that aimed to describe mechanisms in skydiving injuries (phase of jump, mechanism of incident, and mechanism of injury) was developed by ellitsgaard and further developed by westman and bjrnstig. we used one part of the scheme as a phase of deduction to gain better comprehensive understanding (c.f. the categories human factor as a contributor to incidents and injuries and organization and leadership as facilitators or constrainers for reporting emerged inductively ; that is, no premade coding scheme was used and they were formulated from the manifest content of the text passages relating to incidents and injury events and the reporting of incidents. this step aimed to compare prior steps, codes, and categories with the entire text to obtain a sense of what it is about, to seek and identify a common theme, and to more comprehensively understand and interpret the findings. the identified theme named skydiving culture a place for joy, playfulness, and safety awareness provides a description and an understanding of the cultural context present throughout the prior identified categories. the research performed in this study is not regulated by the swedish legislation of research on humans. the authors took into account ethical issues that may have appeared through pursuing the study. prior to each interview, the interviewer informed the respondent of the study 's aim, how long the interview would take, that participation was voluntary, and that the respondent could terminate study participation at any time. the interviewer also informed the respondent that no individual would be named and that respondent integrity and confidentiality would be respected in the presentation of the findings. in order to enhance trustworthiness and transferability, the structuring and analytic procedure was regularly discussed among the three authors. when necessary, codes, categories, and theme were revised, reorganized, added, or omitted to account for the interrelations of the parts and the whole. a second way trustworthiness and transferability was enhanced was through presenting and discussing findings in a group comprised by an expert panel of ten skydiving instructors associated with various skydiving clubs in sweden. the discussion confirmed the general content of categories and theme and no additional changes were made. in the presentation of quotes, the numbers within parentheses represents the consecutive number of the interviewee ; m refers to male and f to female. the first two authors (mats jong and anton westman) are experienced skydivers with approximately 25 years each in the sport. their preunderstanding was a necessary requisite to conduct interviews with skydivers on their own terms, that is, by sharing the same language and culture. mats jong and anton westman had no personal connections to the respondents prior to the interview. during the interviews, all respondents were perceived by the interviewers as being able to speak easily and freely even though the subjects related to experiences of incidents, injury, and death. during the analysis, the two interviewers strived to put their preunderstanding in the background to stay open for what came out from the text. the third author (britt - inger saveman) had no previous knowledge or experience in the sport but had extensive knowledge in the methodology used and the topic of injury and injury prevention ; thereby, the author has been able to approach the topic without preunderstanding. in this study, the term skydiving culture refers to each respondent 's self - defined notion and what it means to them from an individual perspective, including how they experience its relation to injury risks and injury reporting. to present an overall understanding of the topic and the context of the skydiving culture, the theme is presented first, followed by the three categories. skydivers express a constant awareness of imminent injury or death balanced by the positive experiences of being able to pursue the sport. participating in skydiving activities is interpreted as including a form of risk negotiation where the risk of potential injury is balanced against individual benefits in the form of pleasure, progression, and learning in skydiving. in the narratives, it is possible to identify attitudes of risk behavior differing between males and females ; caution is referred to as a feminine characteristic, and the will to develop and progress by pushing limits is referred to as a masculine characteristic. regardless of the gender of the skydiver, these attitudes toward risk behavior remained the same.it's about the same as anywhere else, girls are not that eager to show off or show how tough they are ; girls care more about safety, and at the same time a bit timid and do not dare to test their limits. in that sense, it 's a kind of danger too because they need to learn too. in the end, i believe guys turn out as more skillful skydivers, but girls probably think more about how they do things. (1, f, 150 jumps) it 's about the same as anywhere else, girls are not that eager to show off or show how tough they are ; girls care more about safety, and at the same time a bit timid and do not dare to test their limits. in that sense, it 's a kind of danger too because they need to learn too. in the end, i believe guys turn out as more skillful skydivers, but girls probably think more about how they do things. (1, f, 150 jumps) skydiving is viewed as a sport where males and females can participate and compete on equal terms, but in relation to risk exposure and behavior a recurrent attitude is that it differs between males and females. joy, playfulness, and safety awareness are expressed by both experienced skydivers and those new in the sport. these aspects are associated with several dimensions of interaction relating not only to a sense of belonging to a special group, but also to the direct experience of in - air activities. the aspects of social life and community are also described as important by the respondents:skydiving contains elements of joy in a higher degree than other sports. many sports tend to focus on the elite athlete, but even though we have systems of supporting the elite competitors, there is so much that 's just playing just for fun ! many skydivers jump for several years without competing, or even practicing for competition (13, f, 300 jumps) skydiving contains elements of joy in a higher degree than other sports. many sports tend to focus on the elite athlete, but even though we have systems of supporting the elite competitors, there is so much that 's just playing just for fun ! many skydivers jump for several years without competing, or even practicing for competition (13, f, 300 jumps) both the degree of playfulness and the degree of safety awareness are interpreted as dependent on the subculture of the local drop zone. respondents that have skydived abroad express the view that there is a higher degree of safety awareness among swedish skydivers compared with skydivers in other countries. safety awareness and playfulness are interwoven in the culture of the sport where fellow skydivers, for example, check each other 's equipment prior to boarding the aircraft. a skydiving novice expressed it as:safety awareness does not make you less cool, it 's quite fantastic that people push for safety safety awareness does not make you less cool, it 's quite fantastic that people push for safety skydiving can be dangerous but the experiences of joy and delight outweighs the thoughts of giving up the sport. skydiver knows that each skydive is a potential injury event or could even lead to death. risk and injury are considered a constant ingredient in skydiving and the respondents think about it differently. some want to make the sport as safe as possible, even if it means more regulations are needed while others express pushing the limits individually as part of learning what skydiving is or can be. crossing the limit can lead to injury, but pushing the limit may also lead to learning. an expressed attitude is that the sport and its pursuers are individualists and hence responsible for their own risk - taking acts leading to incidents. incidents and critical events lead to reflections of one 's own and others ' risk in the sport. an experienced skydiver puts this into words:once again, you have an eye - opener and think about the risks in skydiving. i think more of an attitude to life when i think, for example, of an accident like this (a friend 's death) ; you are reminded how fragile life is and how fast it may end. back again to this respect, an awareness that is so important to hold on to. i am definitely guilty of losing it from time to time, when i just push through, and everything works fine. at the same time, i am so grateful to be here and do what we do, and if that has affected my attitude to skydiving, i 'm unsure. still, it is a reminder to respect what we are doing and not to forget that. (4, m, 2300 jumps) once again, you have an eye - opener and think about the risks in skydiving. i think more of an attitude to life when i think, for example, of an accident like this (a friend 's death) ; you are reminded how fragile life is and how fast it may end. back again to this respect, an awareness that is so important to hold on to. i am definitely guilty of losing it from time to time, when i just push through, and everything works fine. at the same time, i am so grateful to be here and do what we do, and if that has affected my attitude to skydiving, i 'm unsure. still, it is a reminder to respect what we are doing and not to forget that. (4, m, 2300 jumps) when asked what constitutes skydiving culture as expressed in the narratives, the safety control system that aimed to prevent incidents with skydivers under the influence of alcohol seems to work properly ; often because of self - regulation where individuals stay on the ground when they have drunk too much the previous day. a breath alcohol tester is used to confirm that the skydiver is not intoxicated and ready to jump. even if the control system works well, the respondents claim that it fails from time to time and some jump despite the control system. reflecting on skydiving culture, a respondent says:well i think about case, for example, and it 's nice. i say unfortunately, it is not so serious to tell new students, ah well, when you 're done with your student training, you 're supposed to buy beer and case with it. case is simple, just buy beer, it happens all the time, so it constitutes skydiving culture. (10, m, 800 jumps)authors note : case is a tradition of buying fellow skydivers a case of beer when passing through different check points or levels in the skydiving sport, for example, after completing student training, first 8-way formation, and first jump from hot air balloon. i say unfortunately, it is not so serious to tell new students, ah well, when you 're done with your student training, you 're supposed to buy beer and case with it. case is simple, just buy beer, it happens all the time, so it constitutes skydiving culture. (10, m, 800 jumps) all respondents in this study had experienced incidents or injury incidents associated with skydiving that occurred at different phases of a jump : from aircraft exit, free fall, parachute opening, parachute flight, and landing. during aircraft exit, bruising and minor lacerations are mentioned as well as strained arms when exiting late while the other group members jump off the plane. several incidents were described as caused by inadequate separation from other skydivers in free fall resulting in or nearly resulting in impact with other skydivers, evoking fear and anger. a respondent describes an incident.well, there was this scary thing which happened ; a kind of close call, some guy opened his parachute below me during a big - way jump (authors ' remark ; in a formation skydiving jump with 20 other skydivers), which scared me a lot. well, there was this scary thing which happened ; a kind of close call, some guy opened his parachute below me during a big - way jump (authors ' remark ; in a formation skydiving jump with 20 other skydivers), which scared me a lot. (8, f, 350 jumps) several incidents happened during parachute opening, for example, when total or partial malfunctions of the main parachute necessitated reserve parachute activation. examples of malfunctions were twisted lines resulting in violently spinning main parachutes or inability to release steering toggles. in conjunction to malfunctions, injury events have occurred because of reduced plan time for a normal parachute landing, or an increased sink rate because of malfunction or a smaller reserve parachute. free fall instability during deployment of the parachute has resulted in events described as horse shoe malfunctions causing, for example, a sprained ankle while landing under two parachutes. incidents associated with wing parachute flight include, for example, downwind landing (high speed more difficult to come to a stop) resulting in a fractured wrist and several near miss mid - air collision incidents at low altitude. other examples of incidents include experienced skydivers describing incidents when they miscalculate hook turns, resulting in bruises and fractures. a respondent who fractured an ankle says,well, once i injured my ankle. it was a hook turn where i waited too long to flare, i landed on my feet but it hurt a lot in one foot. in a way i was lucky, it could have turned out a lot worse if i had been a couple of decimetres lower. it was a hook turn where i waited too long to flare, i landed on my feet but it hurt a lot in one foot. in a way i was lucky, it could have turned out a lot worse if i had been a couple of decimetres lower. (15, m, 1300 jumps) basically, all respondents gave descriptions of incidents or injury events associated with landing, some resulting in bruises, scratches, sprains, and strains but also more severe injuries including sprained crucial ligaments and fractures of legs and spines. events occurred both during unintentional and intentional high - speed landings but also in normal low - speed landings. the quote below from a respondent shows an example of the complexity in an injury event while landing outside the drop zone:well, everything looked just fine. i was planning to land at the nicest spot on the area of clear - cut forest, right in between two tree stumps. it was hard to plan the exact position, but i thought that i could land there. but as i came lower i saw that there was an uprooted tree pointing straight up making the landing area less optimal, at that time i had no choice. my feet stuck and my body continued, hands down in full flare (authors remark ; braking), with no chance to catch myself. my head went straight into the tree stump and everything turned black, and i could hear my neck and back crunch. (2, m, 150 jumps) well, everything looked just fine. i was planning to land at the nicest spot on the area of clear - cut forest, right in between two tree stumps. it was hard to plan the exact position, but i thought that i could land there. but as i came lower i saw that there was an uprooted tree pointing straight up making the landing area less optimal, at that time i had no choice. my feet stuck and my body continued, hands down in full flare (authors remark ; braking), with no chance to catch myself. my head went straight into the tree stump and everything turned black, and i could hear my neck and back crunch. (2, m, 150 jumps) inadequate judgment such as miscalculations and failing to pay attention dominates these descriptions as causes to incidents. additionally, a number of events are described as possibly attributing to female skydivers having less muscular strength than male skydivers. miscalculation of exit point from aircraft is described as a factor causing landings outside (forest areas, roads, and in pasture - land) the drop zones (the designated landing area). another described miscalculation relates to landings at drop zones but where the respondents nearly hit ground obstacles. a lack of insight into one 's own competence and neglecting to undergo proper training about flight characteristics of new equipment was described that as resulting in injuries, for example, using a new wing parachute and realizing that it flew faster at landing than anticipated. failing in attention and judgment was described as affecting reasons for deviating from set plans, leading to incidents and at times injuries, especially in connection with high speed landings. an experienced respondent gives an example of how different distractions compounded while performing a high speed landing led to an incident:what really happened during that jump was that i deviated from my original plan and began improvising, simultaneously other things happened. i had some kind of attention overload, approaching in a different angle than i was used to, the wind had changed, and additionally there were other parachutes drawing attention. i judged that i would be able to turn around and approach in the direction i was aiming to, which added some extra degrees to my turn, and since i had to pay attention to some other chutes i probably had lost some altitude before i initiated my turn. (4, m, 2300 jumps) what really happened during that jump was that i deviated from my original plan and began improvising, simultaneously other things happened. i had some kind of attention overload, approaching in a different angle than i was used to, the wind had changed, and additionally there were other parachutes drawing attention. i judged that i would be able to turn around and approach in the direction i was aiming to, which added some extra degrees to my turn, and since i had to pay attention to some other chutes i probably had lost some altitude before i initiated my turn. (4, m, 2300 jumps) a recurrent statement from the respondents is that females and males perform skydiving in different ways. mentioned by both sexes is the view that females by flying their parachutes too passively do not learn the flying characteristics of their parachute, which may lead to increased risk of injury when encountering situations requiring flexibility and fast unreflective response. an experienced respondent puts this in words by saying,i believe guys hurt themselves for other reason than girls. i can imagine guys hurt themselves more because they are pushing themselves a little bit harder, exceeding their limits. i imagine girls hurt themselves more, not necessarily because they push themselves, but rather because they can not handle the situation. i believe that if you would expose guys and girls to it may sound prejudiced, but i believe that if you put guys and girls in exactly the same situations, then girls would suffer more injuries. i can imagine guys hurt themselves more because they are pushing themselves a little bit harder, exceeding their limits. i imagine girls hurt themselves more, not necessarily because they push themselves, but rather because they can not handle the situation. i believe that if you would expose guys and girls to it may sound prejudiced, but i believe that if you put guys and girls in exactly the same situations, then girls would suffer more injuries. (6, m, 1400 jumps) respondents give examples of when they have been unable to deploy their parachute because of not being able to locate the main parachute activation handle or not having the strength to pull it out resulting in a need to activate the reserve parachute. whether or not an incident or an injury event is reported to the swedish parachuting association (svenska fallskrmsfrbundet, sff) is expressed as depending on a number of distinct reasons. important emerging issues relate to an individuals ' knowledge and definition of what injuries are supposed to be reported, the safety and reporting culture at the local drop zone, organizational structure, and the administration of reports. additionally, the hierarchical structure in the skydiving culture serves either as a facilitator or a constrainer for reporting. the respondents describe comparable injuries that may be reported in some circumstances but not in others. minor bruises and distortions are described as commonly occurring but rarely reported, whereas major injuries (e.g., fractures) are described as being reported to a higher degree. an important incentive to send in a report is whether the injured person expects long - term consequences, for instance, if the injury may lead to impaired mobility. respondents report that the regulations are complex and wish for more clarity in some aspects:today we have all these forms and what is written in the regulations for skydiving, and then it 's not, per definition, really an injury (describing a frostbite), more plain stupidity. i consider the regulations good in many ways, but some issues are dense and stupid. and the form for reporting, maybe we could have incidents on three levels : incidents, injuries, and injuries defined as physical injury ; that may include frostbite by definition, but i believe it is not done. (3, m, 1300 jumps) today we have all these forms and what is written in the regulations for skydiving, and then it 's not, per definition, really an injury (describing a frostbite), more plain stupidity. i consider the regulations good in many ways, but some issues are dense and stupid. and the form for reporting, maybe we could have incidents on three levels : incidents, injuries, and injuries defined as physical injury ; that may include frostbite by definition, but i believe it is not done. (3, m, 1300 jumps) an expressed desire is to see the positive implications from reporting and to be given feedback from the skydiving association and the local club on how the administration of reporting benefits the skydiving community. additionally more experienced skydivers need to take more responsibility in teaching newcomers about reporting and safety issues and to a higher degree enforce the formal routines on the drop zones. a novice female respondent expresses it as follows:i think it is laziness which decides if you report or not. i think you would do it if there 's a routine if i sprain my ankle, someone should come and put that paper in my hand and say that i must do it. if not for that, i would actually not have a thought of reporting. for people like me, you know i think you would do it if there 's a routine if i sprain my ankle, someone should come and put that paper in my hand and say that i must do it. if not for that, i would actually not have a thought of reporting. for people like me, you know (7, f, 90 jumps) although report submission is part of the jump leader 's duties, respondents point out that during jump days, the jump leader is quite busy which may constrain reporting of incidents and injuries authors note : on a swedish skydiving drop zone on a given jump day, ultimate responsibility for safety issues is bestowed an assigned instructor, the jump leader. this person is also responsible to make sure that all incidents related to equipment malfunctions, and injuries leading to health care contacts are reported. the role of the jump leader is, according to the respondents, quite unclear among many skydivers, which may contribute to a chaotic situation when incidents occur. another task of the jump leader, which is highlighted in most interviews, is the commission of restraints as a consequence from unsafe actions or rule violation behavior. what decides if the jump leader acts or not is described as depending on who is reporting and who made the violation. when an experienced skydiver violates regulations resulting in incidents, jump leaders are described as having different incentives not to confront them ; sometimes it may be due to an anticipated negative reaction, or they may hesitate because the skydiver is more experienced than themselves. an experienced respondent says,if they would tell me that i am grounded because of unsafe behavior, then i would take the discussion at the end of the day. but, at the same time, if i am aware that what i was doing was wrong, then i would accept the decision. i think it 's necessary to enforce the authority and formal assignment, but my opinion is that not many jump leaders do so. the experience level should not be so influential because the rules are clear, you can be experienced or inexperienced and as long as there are rules and regulations you should stick to them. (6, m, 1400 jumps) if they would tell me that i am grounded because of unsafe behavior, then i would take the discussion at the end of the day. but, at the same time, if i am aware that what i was doing was wrong, then i would accept the decision. i think it 's necessary to enforce the authority and formal assignment, but my opinion is that not many jump leaders do so. the experience level should not be so influential because the rules are clear, you can be experienced or inexperienced and as long as there are rules and regulations you should stick to them. (6, m, 1400 jumps) an expressed view in the narratives is that skydiving clubs in sweden tend to interpret the national regulations in various ways, which also affects incident reporting. some clubs are believed to conform to the regulations very strictly and even enforce higher demands than the national regulations on their members by, for example, totally prohibiting high - speed landings. on the other side of the spectrum are clubs, which are considered less conforming to the regulations, informally, allowing people to use equipment not suitable to their experience level. depending on the openness of the local drop zone, it is described that skydivers occasionally avoid showing other skydivers that they hurt themselves. thereby injuries are not reported for fear of exposing themselves as having made a bad judgment or being embarrassed for having poor skills. the swedish national rules and regulations regarding safety aspects seem to suggest conformity in the country as a whole regarding skydiving activities, but present results imply the opposite. the respondents express variability between the swedish clubs (drop zones) regarding safety issues and abidance to national rules and regulations. this is in line with a previous finding of variability between the swedish clubs regarding reported nonfatal injury rates 19992003 and also with findings of laurendeau and van brunschot, suggesting that the individual skydiver listens more to fellow skydivers than to rules and regulations about safety measures and skill level required to, for example, jump with a specific parachute or start performing high speed landings. on the individual level, the interpretation is that the risk of injury is viewed as an integrated element of the recreational activity, counterbalanced by its recreational value. the balancing act between risk of injury, death, and recreational value has several implications. in our study respondents claim that they have awareness when their limit is reached and back off when they come too close to the line of danger. however, they simultaneously expressed that challenging the limits is a means of progression and learning. challenging the limits edgework, where the person explores the limits of his / her ability and/or the technology used while maintaining enough control to successfully negotiate the edge. laurendeau and van brunschot develop this further in the skydiving context, saying that edge workers sustain an illusion of control when they are crowding the edge. in high - risk skydiving activities, if injuries do occur, edgework can represent an attempt to push the responsibility away from them, to someone else or some other factor outside themselves. several experienced respondents in our study who have had incidents and injuries express a high degree of self - responsibility, taking into account that incidents happen to them because of their own poor judgment (human error) or lack of skill. noticeably, they acknowledge their own deficiencies but might be influenced by interview directions, where they were encouraged to speak from their own self - experienced perspective and not so much from how they perceive the skill of others. the results are similar to laurendeau and van brunschot, where it also was expressed that skydivers acknowledged occurred incidents as situations for learning and progressing. our finding is also to some extent contrasting to the study of laurendeau and van brunschot, where participants expressed a distance between themselves and those who suffered from injury or died, stating that the other person was doing things that they would never do. they took a stance of blaming the victim, possibly with a subconscious objective to preserve their own sense of control over risks in the sport. landing errors due to poorly executed high speed landings have, worldwide, become an important cause of skydiving - related injuries and deaths [1, 21 ]. parachute associations and parachute manufacturers ' recommend that only highly skilled skydivers perform these maneuvers, but only a limited number of countries or drop zones use regulations to prevent inexperienced skydivers from performing high speed landings [10, 22 ]. nevertheless, drop zones, parachute associations, regulatory authorities, and the skydiving community itself have acknowledged the need for skydivers to be better educated about canopy control and are, hence, arranging canopy piloting courses on basic and advanced levels all over the world (http://www.dropzone.com/). one of the jump leaders ' policing duties includes alcohol use, because in sweden, as in most countries, it is prohibited to skydive under the influence of alcohol and drugs. from our findings, it appears that alcohol consumption and partying are integrated elements in swedish skydiving culture, as in the north american and australian skydiving cultures [2326 ]. control systems exist to prevent skydivers from jumping under the influence of alcohol (jump leader, breath testers), but a previous study found that two out of the 37 fatalities in swedish skydiving 19642003 had a blood alcohol level elevated to the point of impairing cognitive functions. problems and potential risks in skydiving associated with alcohol and illicit drug use need to be more clearly addressed in the safety work within the skydiving community. in line with the discussion above, it may be most important at the local drop zone level. worth noting is that respondents have described some incidents relating to the free fall sequence. in sweden, a hard helmet is compulsory until you have a b - license (> 100 jumps after student status), but as a voluntary action most skydivers in sweden, regardless of rating, use hard helmets to prevent injury. is seen, where experienced surfers make the choice not to use head protection, referring to impaired hearing and feeling restrained. from the findings, we can see that inadequate judgment is described as a major cause and contributing factor to incidents. stressors affecting judgment can emerge during the full sequence of a jump, from prejump activities to landing. when several stressors emerge simultaneously, the person is at risk of making a hasty / bad decision. this is similar to the concept of sensory overload, where input of several never - ending cognitive stimuli results in mood changes and irrational psychological behavior. the incidents or injury events described in this study chiefly appear to be perceived by the respondents as attributable to human error (i.e., inadequate decision). reasons for this operator - oriented view among respondents might be connected to their levels of knowledge, insights of the risk associated with the sport, and their innate motivation for pursuing the sport. the complexity of the chain of events leading to an incident can, at times, be connected to the equipment used ; for example, the placing of handles for deploying the reserve parachute may be different depending on bodily position. problems with the technical equipment (airplane, parachute, altimeters, helmets, etc.) are, in general, rare and not explicitly mentioned by the respondents in this study.. nevertheless, there are equipment - related incidents mentioned by the respondents that possibly occurred due to insufficient muscular strength. skydivers need to test the deployment systems on the ground from time to time to ensure that they have sufficient muscle strength to activate their parachute, and additionally the parachute industry must continue to monitor their standards to prevent gear - related incidents. our results suggest that the skydiving community and subculture have an influence on safety awareness and on reporting of incidents and injuries among swedish skydivers. it is, in line with high - reliability theory, necessary to raise this issue further to understand how subculture can facilitate reporting so that appropriate action can be taken to prevent or reduce the risk of incidents and injuries. healthcare researchers and other high reliability organizations have similarly put forth issues of subculture and workplace climate factors, such as burdensome administration and lack of feedback, as obstacles for reporting. barach and small have, in other types of aviation, noted similar results where fear of reprisal, lack of trust, code of silence, and skepticism are mentioned as reporting barriers. it may not only be necessary to identify errors for reporting, the people involved in the culture need to see the results and how it is used in order to see the meaning of from reporting. in a study by waring, the participating physicians see reporting as pointless, since the errors are an inevitable and potentially unmanageable feature of medical work. another article from the healthcare setting puts forth that incident reporting does have a role in safety work and care processes, by indirectly affecting the attitudes and knowledge of those working there. barach and small conclude that confidential incident reporting systems have a decisive role in identifying errors on the system level and that it is necessary to shift from a punitive to a collaborative mindset that seeks to identify and understand the underlying system failures. in that sense, reporting circumvents the culture of blame. in this study, skydiving culture as a concept was understood from the participants self - defined understanding. a more comprehensive and complex concept of skydiving culture, including issues of gender, injury risks, risk behavior, and subculture has been scrutinized from a sociological perspective by several authors in the north american and australian contexts [3, 23, 26, 33 ], wade, and brymer in the north american and australian contexts. organization and leadership aspects within the skydiving community can serve both as facilitators as well as constrainers to reporting. following this line, perhaps a way of addressing safety issues and improving incident and injury reporting would be to work bottom up instead of top down, to initiate / promote discussions at local drop zones, educate jump leaders more thoroughly, and influence all categories of skydivers to reflect on how they pursue skydiving, the related risk taking, and incidents. this has similarities to the conclusions from a review on the safety systems topic within healthcare settings where it was stressed that in order to learn the lesson and take adequate actions inside and across organizations, local and national systems must work together closely giving constant feedback to those involved in reporting incidents. our proposition to national parachuting associations is to promote a system, preferably web - based, where skydivers can report incidents anonymously and injuries related to all aspects of skydiving, including while aboard aircraft. starting in 2013, the swedish parachuting association (sff) launched such a system in part because of the contributions from our research group. the present findings suggest that jump leaders and other instructors act inconsistently when critical situations / incidents occur, for instance, depending on who is reporting and who had a violation. it also appears that respondents (with knowledge of the content) view the regulations as adequate and even express that jump leaders should be more stringent in enforcing them. power structures might become relevant when the formal power of the jump leader is overridden by a skydiver with more experience or higher instructor ratings, thereby holding more informal power on the hierarchical ladder. in line with the writings of laurendeau. [3, 23, 26, 33 ] the hierarchical structures play a substantial role in the swedish skydiving setting ; again they pinpoint variations among the swedish clubs regarding safety issues and abidance to national rules and regulations. because of the qualitative approach and the limited sample size of this study, it is impossible to generalize the findings to the larger population of skydivers on a national or international level in quantitative terms. by presenting quotes as well as validating the analysis in a group of expert skydiving instructors, we have tried to enhance trustworthiness and transferability. although an effort was made to include a broad range of skydivers with respect to age and gender, the sample has a relatively high level of experience (years of skydiving and number of jumps). this may have affected the data in different ways but probably by enhancing data quality in that experienced respondents have acquired knowledge of the subject matter and have extensive personal experience of incidents and injuries ; thereby, they provide reliable accounts of their experiences. on the basis of the results presented above, it is interpreted that safety work and incident reporting in swedish skydiving may be influenced more by local drop zone culture than by the national association policy. formal and informal hierarchical structures among skydivers seem to dictate how skydiving is practiced, how rules are enforced, and if incidents or injuries are reported. these findings suggest that a change of safety work doctrine may be of value, from a present top - down to a bottom - up perspective, further empowering the individual skydiver. in practical terms, this could mean ensuring a fast, comprehensive bidirectional flow of information between the skydiver and reporting agency after having submitted an incident or injury incident report, thereby giving meaning to both the adverse event and the act of reporting. | the objective was to illuminate the experience of injuries and the process of injury reporting within the swedish skydiving culture. data contained narrative interviews that were subsequently analyzed with content analysis. seventeen respondents (2244 years) were recruited at three skydiving drop zones in sweden. in the results injury events related to the full phase of a skydive were described. risk of injury is individually viewed as an integrated element of the recreational activity counterbalanced by its recreational value. the human factor of inadequate judgment such as miscalculation and distraction dominates the descriptions as causes of injuries. organization and leadership act as facilitators or constrainers for reporting incidents and injuries. on the basis of this study it is interpreted that safety work and incident reporting in swedish skydiving may be influenced more by local drop zone culture than the national association regulations. formal and informal hierarchical structures among skydivers seem to decide how skydiving is practiced, rules are enforced, and injuries are reported. we suggest that initial training and continuing education need to be changed from the current top - down to a bottom - up perspective, where the individual skydiver learns to see the positive implications of safety work and injury reporting. |
there is a longstanding discourse on whether self - reported health is a good measure of objective health. objective health indexes include mortality, life expectancy and diagnosed morbidity, which provide a great degree of precision in the measurement of health. those measures have been used for centuries by mathematicians, demographers and epidemiologists to provide insights into the health of an individual, community or population. while the objective health indexes do have a high probability of mathematical empiricism, which make for validity and reliability in comparisons across different population characteristics, they are narrow in evaluating a range of issues affecting the health of people. life expectancy germinates from mortality data, which speaks to lived years and not quality of the lived time. like life expectancy and mortality, morbidity is caused by some disease causing pathogens that further justify the causal relation between morbidity and health. historically, policy makers including doctors relied on research findings on the causes of particular dysfunctions in order to formulate measures to address their reduction or eradication. health therefore was viewed as the absence of diseases ; hence, the alleviation of morbidity meant a healthy person or population. but the absence of diseases still does not imply that an individual or population is healthy, as this is the further extreme of the health continuum. it was this gap in the discourse and the accepted limitation of objective indexes of health that led the world health organization (who), in the late 1940s, to forward a conceptual definition of health. the who 's definition of health stipulated that it goes beyond the mere absence of diseases to social, psychological and physical wellbeing. health was no longer the absence of diseases but different tenets of wellbeing. although who 's perspective outlined the way forward, and sought to provide a platform for which an expansion in objective health could begin, some scholars opined that it was too vague and elusive a conceptualization. in spite of those critiques, some researchers began using subjective indexes to measure health instead of the traditional objective indexes. the subjective measures are 1) happiness ; 2) life satisfaction, 3) self - reported health status, and self - reported illness[415 ]. diener postulated that happiness can be used to measure subjective wellbeing (i.e. health). he opined that happiness expends beyond and implicitly takes into account more aspects of an individual 's life than the objective indexes. happiness like life satisfaction, self - reported health has a common denominator, people 's perception of their general quality of life. although this is in keeping with that comprehensive broad conceptual definition of health forwarded by the who more than the narrow biomedical approach diagnosed morbidity, life expectancy or mortality the debate about the validity of those subjective indexes continue. scientific literature on health has revealed that self - rated health status is highly reliable a measure to proxy health and that this successfully crosses cultural lines. odonnell and tait concluded that self - reported health status can be used to indicate wellbeing as they found that all respondents who had chronic diseases reported very poor health. another group of scholars concurred with the aforementioned findings when their findings revealed that the statistical association between happiness and subjective wellbeing (i.e. self - reported health) was a strong one - correlation coefficient r = 0.85 in the 18 oecd countries. in that same study, the research found a weak relation between objective measures of health and self - reported health. this highlights the disparity in measures, the need for more empirical studies and implicitly has not address the biasness in the subjectivity of the subjective indexes. the subjective indexes introduced the issue of biasness in recall and perception as subjectivity denotes people 's perceptions. perception is highly biased as people can provide an inflated or deflated account of their state in an interview or on a self - administered questionnaire. it is for this reason why empirical researchers avoid and decry its utilization in the measurement of health. although subjective indexes are in keeping with the who 's widened definition of health, their biasness must be understood as challenges for researchers. the discourse on subjective wellbeing, using survey data, can not be denied that it is based on person 's judgment, and therefore must be prone to systematic and non - systematic biases. in an earlier work, diener argued that the subjective measure seemed to contain substantial amounts of valid variance ; suggesting that this indicated the validity of subjective indexes. kahneman devised a procedure of integrating and reducing the subjective biases when he found that instantaneous subjective evaluations are more reliable than assessments of recall of experiences. this highlights the biasness therefore that remain in cross - sectional survey that asked people to remember over a long time. embedded in the aforementioned findings are whether particular subjective indexes that comprised of recall over 2 - 4 weeks is a good measure for objective indexes of health. embodied in the literature is the need to carry out empirical research on subjective and objective indexes with emphasis on subjective indexes that are not on instantaneous assessment. using data for jamaica, the aims of this study are to 1) examine the relationship between particular subjective and objective indexes ; 2) investigate the validity of 2 - 4 week subjective index (self - reported illness over a 4-week period) in measuring objective indexes (i.e. life expectancy and mortality) ; 3) evaluate the differences that exist between the measurement of subjective and objective indexes by the sexes ; and 4) provide policy makers, other researchers, public health practitioners as well as social workers with research information with which can be used to inform their directions. the current study utilized secondary published data from the statistical institute of jamaica, and the planning institute of jamaica and the statistical institute of jamaica. life expectancy and mortality were from the statistical institute of jamaica, and self - reported illness from the planning and statistical institutes of jamaica. generally, data were for two decades (1989 - 2007) ; however, life expectancy data were only available for some of those years. data were stored, retrieved and analyzed using spss for windows 16.0 (spss inc ; chicago, il, usa). scatter diagrams were employed to establish 1) statistical associations, and 2) linearity and non - linearity between variables under examination. multiple regression, using the enter method, was employed to a predictive model of linear associations. models were built for 1) general life expectancy and self - reported illness of jamaicans ; 2) life expectancy and self - reported illness of the sexes. a 95% confidence interval would be used to examine whether a variable is statistical significant or not. where lep (life expectancy at birth for the population at a given period) is a function of self - reported illness (spip) of population at a given period and some residual error (). self - reported illness : the percent of people who reported having had an illness / injury in the 4-week period of the survey for a given year. the average number of years of new - born would live if subject to the mortality patterns of the cross - sectional population at the time of his / her birth. objective health : this variable constitutes life expectancy and mortality of a given population at a particular time. self - reported illness : the percent of people who reported having had an illness / injury in the 4-week period of the survey for a given year. the average number of years of new - born would live if subject to the mortality patterns of the cross - sectional population at the time of his / her birth. objective health : this variable constitutes life expectancy and mortality of a given population at a particular time. self - reported illness : the percent of people who reported having had an illness / injury in the 4-week period of the survey for a given year. the average number of years of new - born would live if subject to the mortality patterns of the cross - sectional population at the time of his / her birth. objective health : this variable constitutes life expectancy and mortality of a given population at a particular time. in 1989, life expectancy at birth for the jamaican population was 72.5 years and this has increased to 73.12 year in 2007 (table 1). disaggregating population life expectancy at birth revealed that in 1989, a female child was likely to outlive a male - child by 3 years. one and one - half decades later this difference increased to 6 years. over the 2 decades, the self - assessed difference in ill status of females increased from 3.5% (in 1989) to 4.7% in 2007. concurrently, general self - reported illness over a 4-week period declined from 16.8% to 15.5%, with a mean self - reported illness of 12.5% (sd = 2.6%). mortality declined by 9.2% ; with a mean mortality over the 2 decades being 15,829 people (sd = 1,616 people). life expectancy at birth for the sexes, self - reported illness, and mortality, 1989 - 2007 assessing illness from a 4-week period, figure 1 found a strong significant association between life expectancy at birth for the jamaican population and self - reported illness (correlation coefficient, r = -0.731). fifty - four percent of life expectancy can be accounted for by self - reported illness (r = 0.535). mortality (in no of people) and self - reported illness / injury (%) based on table 2, if all other things remain constant (i.e. not change) which denotes that self - reported illness would be naught, a jamaican child at birth on average would be expected to live for 75.6 years (95% confidence interval : 73.9, 77.3 years). with every 1% increase in self - reported illness, life expectancy is expected to decline by 0.17 years (i.e. 2 months). life expectancy at birth of population and sex of children by self - reported illness based on figure 1 the data for mortality (in number of people) and self - reported illness (%) is best fitted by a non - linear curve. concomitantly, when self - reported illness of the population (%) is less than 11%, the significant statistical correlation between self - reported illness and mortality is a negative one. when self - reported illness lies between 11% and 16%, mortality begins to increase indicating the direct statistical association between both variables. when self - reported illness exceeds 16%, the association between the two variables changes to a negative one. life expectancy at birth of female jamaica and self - reported illness of female (assessed based on a 4-week period) are moderately negatively correlated with each other (correlation coefficient, r = - 0.683). forty - seven percent of the variance in life expectancy at birth of a female child in jamaica can be explained by 1% change in self - reported illness of females (fig. life expectancy at birth for female by self - reported illness of female (%). there is a negative moderate correlation between life expectancy at birth of a female and self - reported illness of female (%) correlation coefficient = 0.683. forty - seven percent of the variance in life expectancy at birth of a female can be accounted for by 1% change in self - reported illness females (%). table 2 revealed that if self - reported illness were equals to zero, life expectancy of a female child at birth on average would be 83.3 years (9% % confidence interval = 75.4, 91.3 years). with every 1% increase in self - reported illness, life expectancy will decline by 0.53 years (or 6 months) (95% confidence interval = -1.031, -0.024 years). life expectancy at birth for a male is strongly associated with self - reported illness of males (in %) correlation coefficient, r = - 0.796. sixty - three percent of the variance in life expectancy at birth of a male can be explained by self - reported illness (in %) (fig. 3). life expectancy at birth for male by self - reported illness of male (%). there is a strong negative significant statistical correlation between life expectancy at birth of a male and self - reported illness of male (in %) - correlation coefficient, r = - 0.796. sixty - three percent of the variance in life expectancy at birth of a male can be explained by self - reported illness (%). if self - reported illness were zero, average life expectancy of a male child in jamaica would be 72.7 years (95% confidence interval = 71.3, 74.1 years) (table 2). with each additional increase in self - reported illness (i.e. 1%), life expectancy of a male the data for mortality (in number of people) and self - reported illness (in %) is best fitted by a non - linear curve. concomitantly, when self - reported illness of the population (in %) is less than 11%, the significant statistical correlation between self - reported illness and mortality is a negative one. when self - reported illness lies between 11% and 16%, mortality begins to increase indicating the direct statistical association between both variables. when self - reported illness exceeds 16%, the association between the two variables changed to a negative one. the use of a single variable to explain the objective indexes may create the impression that only one explanatory variable is important. this is a limitation of the study as the researcher wants to examine one independent variable (i.e. self - reported illness in a 4-week reference period) in order to establish whether it is a good measure of objective indexes and whether differences exist between the sexes. assessing illness from a 4-week period, figure 1 found a strong significant association between life expectancy at birth for the jamaican population and self - reported illness (correlation coefficient, r = -0.731). fifty - four percent of life expectancy can be accounted for by self - reported illness (r = 0.535). mortality (in no of people) and self - reported illness / injury (%) based on table 2, if all other things remain constant (i.e. not change) which denotes that self - reported illness would be naught, a jamaican child at birth on average would be expected to live for 75.6 years (95% confidence interval : 73.9, 77.3 years). with every 1% increase in self - reported illness, life expectancy is expected to decline by 0.17 years (i.e. 2 months). life expectancy at birth of population and sex of children by self - reported illness based on figure 1 the data for mortality (in number of people) and self - reported illness (%) is best fitted by a non - linear curve. concomitantly, when self - reported illness of the population (%) is less than 11%, the significant statistical correlation between self - reported illness and mortality is a negative one. when self - reported illness lies between 11% and 16% when self - reported illness exceeds 16%, the association between the two variables changes to a negative one. life expectancy at birth of female jamaica and self - reported illness of female (assessed based on a 4-week period) are moderately negatively correlated with each other (correlation coefficient, r = - 0.683). forty - seven percent of the variance in life expectancy at birth of a female child in jamaica can be explained by 1% change in self - reported illness of females (fig. 2). life expectancy at birth for female by self - reported illness of female (%). there is a negative moderate correlation between life expectancy at birth of a female and self - reported illness of female (%) correlation coefficient = 0.683. forty - seven percent of the variance in life expectancy at birth of a female can be accounted for by 1% change in self - reported illness females (%). table 2 revealed that if self - reported illness were equals to zero, life expectancy of a female child at birth on average would be 83.3 years (9% % confidence interval = 75.4, 91.3 years). with every 1% increase in self - reported illness, life expectancy will decline by 0.53 years (or 6 months) (95% confidence interval = -1.031, -0.024 years). life expectancy at birth for a male is strongly associated with self - reported illness of males (in %) correlation coefficient, r = - 0.796. sixty - three percent of the variance in life expectancy at birth of a male can be explained by self - reported illness (in %) (fig. 3). life expectancy at birth for male by self - reported illness of male (%). there is a strong negative significant statistical correlation between life expectancy at birth of a male and self - reported illness of male (in %) - correlation coefficient, r = - 0.796. sixty - three percent of the variance in life expectancy at birth of a male can be explained by self - reported illness (%). if self - reported illness were zero, average life expectancy of a male child in jamaica would be 72.7 years (95% confidence interval = 71.3, 74.1 years) (table 2). with each additional increase in self - reported illness (i.e. 1%), life expectancy of a male will decline by 0.17 year (2 months) (95% confidence interval = 0.289, 0.055). based on figure 1 the data for mortality (in number of people) and self - reported illness (in %) is best fitted by a non - linear curve. concomitantly, when self - reported illness of the population (in %) is less than 11%, the significant statistical correlation between self - reported illness and mortality is a negative one. when self - reported illness lies between 11% and 16% when self - reported illness exceeds 16%, the association between the two variables changed to a negative one. the use of a single variable to explain the objective indexes may create the impression that only one explanatory variable is important. this is a limitation of the study as the researcher wants to examine one independent variable (i.e. self - reported illness in a 4-week reference period) in order to establish whether it is a good measure of objective indexes and whether differences exist between the sexes. assessing illness from a 4-week period, figure 1 found a strong significant association between life expectancy at birth for the jamaican population and self - reported illness (correlation coefficient, r = -0.731). fifty - four percent of life expectancy can be accounted for by self - reported illness (r = 0.535). mortality (in no of people) and self - reported illness / injury (%) based on table 2, if all other things remain constant (i.e. not change) which denotes that self - reported illness would be naught, a jamaican child at birth on average would be expected to live for 75.6 years (95% confidence interval : 73.9, 77.3 years). with every 1% increase in self - reported illness, life expectancy is expected to decline by 0.17 years (i.e. 2 months). life expectancy at birth of population and sex of children by self - reported illness based on figure 1 the data for mortality (in number of people) and self - reported illness (%) is best fitted by a non - linear curve. concomitantly, when self - reported illness of the population (%) is less than 11%, the significant statistical correlation between self - reported illness and mortality is a negative one. when self - reported illness lies between 11% and 16% when self - reported illness exceeds 16%, the association between the two variables changes to a negative one. life expectancy at birth of female jamaica and self - reported illness of female (assessed based on a 4-week period) are moderately negatively correlated with each other (correlation coefficient, r = - 0.683). forty - seven percent of the variance in life expectancy at birth of a female child in jamaica can be explained by 1% change in self - reported illness of females (fig. 2). life expectancy at birth for female by self - reported illness of female (%). there is a negative moderate correlation between life expectancy at birth of a female and self - reported illness of female (%) correlation coefficient = 0.683. forty - seven percent of the variance in life expectancy at birth of a female can be accounted for by 1% change in self - reported illness females (%). table 2 revealed that if self - reported illness were equals to zero, life expectancy of a female child at birth on average would be 83.3 years (9% % confidence interval = 75.4, 91.3 years). with every 1% increase in self - reported illness, life expectancy will decline by 0.53 years (or 6 months) (95% confidence interval = -1.031, -0.024 years). life expectancy at birth for a male is strongly associated with self - reported illness of males (in %) correlation coefficient, r = - 0.796. sixty - three percent of the variance in life expectancy at birth of a male can be explained by self - reported illness (in %) (fig. 3). life expectancy at birth for male by self - reported illness of male (%). there is a strong negative significant statistical correlation between life expectancy at birth of a male and self - reported illness of male (in %) - correlation coefficient, r = - 0.796. sixty - three percent of the variance in life expectancy at birth of a male can be explained by self - reported illness (%). if self - reported illness were zero, average life expectancy of a male child in jamaica would be 72.7 years (95% confidence interval = 71.3, 74.1 years) (table 2). with each additional increase in self - reported illness (i.e. 1%), life expectancy of a male will decline by 0.17 year (2 months) based on figure 1 the data for mortality (in number of people) and self - reported illness (in %) is best fitted by a non - linear curve. concomitantly, when self - reported illness of the population (in %) is less than 11%, the significant statistical correlation between self - reported illness and mortality is a negative one. when self - reported illness lies between 11% and 16%, mortality begins to increase indicating the direct statistical association between both variables. when self - reported illness exceeds 16%, the association between the two variables changed to a negative one. the use of a single variable to explain the objective indexes may create the impression that only one explanatory variable is important. this is a limitation of the study as the researcher wants to examine one independent variable (i.e. self - reported illness in a 4-week reference period) in order to establish whether it is a good measure of objective indexes and whether differences exist between the sexes. empirical analyses have examined the subjective and objective wellbeing phenomenon, and have provided some platform for a partial resolution of the matter. using cross - sectional data, researchers established that there was a significant statistical relation between subjective wellbeing (self - reported wellbeing) and objective wellbeing. dienerfound a strong correlation between the two variables, which disagreed with kahneman and riis, who found correlation coefficient between subjective happiness and self - reported health to be strong ; but the statistical association between self - reported health and objective health. the current research concurs with both diener and not kahneman and riis in one instance as the correlation between self - reported illness (i.e. subjective index) and objective health (i.e. life expectancy) for the population was a strong one, correlation of coefficient, r = 0.731. the evidence here is both that the association is a strong one and that it is negative, suggesting that life expectancy deteriorates with more self - reported illness. this justifies the increase in life expectancy at birth for jamaicans in 2007 over 1989 as the percentage of self - reported illness declined by 1.3%. however on the other hand, when the objective index is mortality, the statistical association between objective health and self - reported illness (i.e. subjective index) was very weak. the studies of diener and kahneman and riis assume that the sexes operate in the same manner which means that what applies to the general populace is the same across the sexes. this study did not make that assumption ; instead the researcher examined whether there was a disparity between the sexes and if there were any, what these were. this work revealed that strong significant correlation between objective health (i.e. life expectancy at birth for jamaicans) and self - reported illness of both sexes differs by male and female. the findings showed that self - reported illness was more an explanation of life expectancy of males than of females. interestingly to note that self - reported illness accounted for less than one - half of life expectancy of females but close to two - thirds for males. kahneman suggested that instantaneous self - assessment of health is a good measure of subjective health unlike self - evaluations that occur over a longer period of time. this study found that self - reported illness over a 4-week period of time is not immediate and is still a good measure of life expectancy ; but not mortality. embedded in this finding is the fact that subjective index can be instantaneous unlike kahneman 's finding. the current study did not examine beyond a 4-week period and while it was not immediate does not say that we can totally disregard time in recall. the matter may not show any difference for the general population ; but this would be different for particular age cohorts elderly. evolutionary biology has shown that cells degenerate with ageing, suggesting that functional capacity in particular mental faculties will not on average be as good as in earlier years[2429 ]. it is within the context of ageing that kahneman 's perspective may be even more potent as a 4-week period will not seek challenges in recall for the young or middle age people but this could be so for the aged. gaspart opined on the difficulty of using objective quality of life in measuring wellbeing and put forward a perspective that self - reported wellbeing should replace this measurement. so its objectivism is already contaminated by post - welfarism, opening the door to a mixed approach, in which preferences matter as well as objective wellbeing which speaks to the necessity of using a measure that captures more of the multidimensional construct of health than the traditional income per capita. wellbeing depends on both the quality and the quantity of life lived by people, which argues more for subjective indexes than objective ones. the current study revealed that self - reported health is a good measure of life expectancy but a poor measure of mortality in jamaica. therefore those studies that have used self - rated illness (or health conditions)[3134 ] to evaluate health of jamaicans or particular sub - groupings with the population were good in capturing health ; but that researchers must be cognizant of the differences that do exist between the validity of particular objective indexes used and self - reported illness as well as the sex disparity in validity of subjective index in measuring health. self - reported illness therefore is a good measure of health as self - rated health status or life expectancy. simply put, using self - reported illness to evaluate health of females is less reliable than of assessing males health ; and that subjective health (self - reported illness) is a good measure of objective health (life expectancy) in jamaica. life expectancy at birth is widely used to measure quality of life in a country or of a people in particular geographic region. it is among the objective indexes used by some demographers and economists to evaluate health status of people and a population. this study found that self - reported illness in a 4-week reference period is a good measure of objective health (life expectancy at birth for the population of jamaica). however, self - reported illness is a poor measure of mortality. on disaggregating life expectancy and self - reported illness data by sexes, it was revealed that self - reported illness for males was a better measure for objective health than for females. the literature revealed that subjective indexes of health is a good measure if people are asked to report on their health current and not over any long period of time. the current study disagrees with the literature that for subjective index (i.e. self - reported illness) to be a good measure of health it must be instantaneous as this work found that subjective index over a 4-week was a good measure of life expectancy. this does not denote that the period extends beyond 4 weeks ; but that 1) self - reported illness is a good measure of objective index (life expectancy) ; 2) subjective index is a better measure of objective index (life expectancy) for males than females ; 3) subjective index is not a good measure for mortality, and 4) self - reported illness can be used to measure health as self - rated health status, happiness, or life satisfaction. | background : there is a longstanding discourse on whether self - reported health is a good measure of objective health. this has never been empirical examined in jamaica.aims:study seeks to 1) examine the relationship between particular subjective and objective indexes ; 2) investigate the validity of a 4-week subjective index in measuring objective indexes ; 3) evaluate the differences that exist between the measurement of subjective and objective indexes by the sexes ; and 4) provide policy makers, other researchers, public health practitioners as well as social workers with research information with which can be used to inform their directions.materials and methods : data published by the statistical institute of jamaica, and the planning institute of jamaica and the statistical institute of jamaica were used for this study. descriptive statistics were used to provide background information on data. scatter diagrams were employed to establish 1) statistical associations, and 2) linearity and non - linearity between variables under examination. multiple regression, using the enter method, was employed to a predictive model of linear associations.results:a strong significant association was found between life expectancy at birth for the jamaican population and self - reported illness (r = -0.731) ; and this was weaker females (r = - 0.683) than males (r = - 0.796). however, the relationship between mortality and self - reported illness was a weak non - linear one.conclusions:self-reported illness in a 4-week reference period is a good measure of objective health and that self - reported illness for males was a better measure for objective health than for females. |
array - comparative genomic hybridization (a - cgh) assay has made the genome - wide screening of genomic copy - number variations (cnvs) possible, enabling to assign genetic diagnoses to phenotypes, which could not be accounted for in the past. microcephaly, disproportionate pontine and cerebellar hypoplasia (micpch) syndrome [online mendelian inheritance in man (omim) number 300749 ], a rare clinico - radiological phenotype, was first described by najm. and linked to calcium / calmodulin - dependent serine protein kinase (cask) gene mutations. the core phenotype comprises severe neurodevelopmental delay, microcephaly, and disproportionate pontine and cerebellar hypoplasia. neuroradiological features associated with cask mutations have been refined by takanashi. to date, forty five or so female patients with characteristic phenotype and two male patients with lethal form have been reported. we report a girl with clinico - radiologic features of micpch syndrome, whose conventional cytogenetic analysis was normal and a subsequent a - cgh analysis discovered microduplication in cask gene at xp11.4. a 2-year - old asian girl was referred to pediatric neurology service with global developmental delay and growth restriction. she could sit unaided and roll over, but was unable to stand without support. she was born at term by normal vaginal delivery to un - related healthy parents. pregnancy was unremarkable for infection, exposure to known teratogens, polyhydramnios or decreased fetal movements. she was both breast and bottle fed. during the weaning period, she struggled with lumpy food and failed to gain weight beyond 6 months. clinical assessment revealed microcephaly, low weight (< 0.4 centile), an open mouthed appearance with thickened alveolar ridges, prominent maxilla, bilateral epicanthic folds, short nose, long philtrum, large ears, hypoplastic 5 toe nails, delayed neurodevelopmental milestones, low axial tone, and slightly increased peripheral tone, more so in the lower limbs. as a part of her diagnostic work - up, she underwent extensive investigations. magnetic resonance imaging (mri) showed prominent lateral ventricles, mega cisterna magna, small cerebellum, and normal corpus callosum [figure 1 ]. neurometabolic investigations were normal and toxoplasmosis, rubella, cytomegalovirus, herpes simplex (torch) studies were negative. note the hypoplastic pons and cerebellum with normal appearance of the corpus callosum she was referred to clinical genetics team with a view to assigning a syndromic diagnosis. subsequently, an a - cgh analysis was carried out, which revealed cask gene duplication at xp11.4. micpch syndrome is a rare x - linked genetic disorder caused by cask gene mutations and is characterized by neurodevelopmental delay and specific brain malformations. cask, a multi - domain scaffolding protein, is a member of membrane associated guanylate kinase protein family, which regulates presynaptic neurotransmitter release, postsynaptic ion - channel function, and expression of genes associated with brain development. evidence suggests that loss - of - function cask gene mutations lead to x chromosome inactivation, causing severe phenotype, whereas hypomorphic missense cask mutations produce less severe phenotypes. deletions and intragenic mutations have been associated with micpch syndrome more commonly than duplications. almost invariably, the cask genetic aberrations are de novo, resulting most commonly from the mutational mechanism of non - allelic recombination. najm studied four females and one male who died in neonatal period to describe the core phenotype and found cnvs, gene inversion and single nucleotide polymorphism as the possible mutational mechanisms. hayashi in his ten cases discovered nonsense mutations, 2-bp deletions, exon - intron junction mutations, interstitial duplications, and heterozygous deletions with almost equal frequency. moog reported 20 patients of which 11 showed submicroscopic cnvs, including nine deletions and two duplications in the cask gene. recently, burglen have reported 13 patients (11 females and 2 males) with de novo cask gene mutations, 10 being intragenic mutations and 3 xp11.4 deletions. the core micpch syndrome clinical phenotype, originally described by najm, was further defined by moog, and confirmed by burglen. it includes severe neurodevelopmental delay, varying degrees of congenital microcephaly, severe postnatal microcephaly (occipitofrontal circumference < 3.5 sd) by 1 year of age, commonly associated with feeding difficulties, postnatal growth restriction, axial hypotonia, peripheral hypertonia, and occasional optic nerve hypoplasia and/or other eye abnormalities and sensorineural hearing impairment. dysmorphic features comprised prominent and/or broad nasal bridge and tip, small or short nose, long philtrum, small chin, and/or large ears, hypoplastic toe nails etc. takanashi described the radiological phenotypic spectrum associated with cask gene mutations, which confirmed the findings of najm and was, in turn, corroborated by observations recorded by moog mri revealed varying degrees of brainstem and cerebellar hypoplasia and in some cases, showed increase in the fourth ventricle size, subtle changes in gyral pattern in frontal cortex, and mild dilatation of lateral ventricles. takanashi also concluded that a relatively normal corpus callosum with low cerebrum / corpus callosum ratio in a girl with microcephaly and neurodevelopmental delay, alludes to the possibility of cask gene mutation, as the pontocerebeller hypoplasia in non - cask gene mutations is associated with thinning of corpus callosum. severe neurodevelopmental delay, marked microcephaly, small cerebellum, prominent lateral ventricles, and dysmorphic features such as short nose, long philtrum, prominent maxilla, and large ears fit in the clinico - radiologic phenotype described. normal appearing corpus callosum (cc) in our patient is in line with observations made by takanashi. minimal vermis involvement in our case was reported by moog in patient 10, 11, and 12. as seen in our case, hypoplastic toe nails were documented in patient 7 by moog and patient 10 by burglen. fourth ventricle size was near normal in our case as was reported by moog in five of their patients. although, typically cerebellum and vermis are affected equally, our case, like patient 7 of moog and patients 10, 11 and 12 of burglen had a subtly affected vermis. cask gene duplication, found in our case, has been reported only in a small number of reported micpch syndrome cases and therefore, seems to be a less common mutational mechanism to produce michpch syndrome. despite extensive investigations in our case, the diagnosis remained elusive until a - cgh analysis uncovered micro - duplication, which was earlier reported in two cases by hayashi and in patients 21 and 25 reported by moog. based on the preceding discussion, it can be suggested that in girls presenting with severe neurodevelopmental delay and microcephaly, if neuroimaging depicts ponto - cerebellar hypoplasia with normal cc, a - cgh analysis may be carried out to ascertain genetic diagnosis. micpch syndrome, mostly seen in girls, is caused by de novo loss - of - function cask gene mutations in x - chromosome in the xp11.4 region, producing null alleles. clinicians assessing girls presenting with severe developmental delay and microcephaly can use the radiological features of ponto - cerebellar hypoplasia with normal corpus callosum and low cerebrum / cc ratio as a guide to look for cask gene mutations by using a - cgh analysis. | microcephaly, disproportionate pontine and cerebellar hypoplasia (micpch) syndrome, a rare x - linked disorder, generally seen in girls, is characterized by neurodevelopmental delay, microcephaly, and disproportionate pontine and cerebellar hypoplasia. it is caused by inactivating calcium / calmodulin - dependent serine protein kinase (cask) gene mutations. we report a 2-year - old girl with severe neurodevelopmental delay, microcephaly, minimal pontine hypoplasia, cerebellar hypoplasia, and normal looking corpus callosum, with whom the conventional cytogenetic studies turned out to be normal, and an array - comparative genomic hybridization (a - cgh) analysis showed cask gene duplication at xp11.4. our case highlights the importance of using clinico - radiologic phenotype to guide genetic investigation and it also confirms the role of a - cgh analysis in establishing the genetic diagnosis of micpch syndrome, when conventional cytogenetic studies are inconclusive. |
cardiac resynchronization therapy (crt) is an effective and well - established therapy for patients suffering with heart failure (hf), left ventricular (lv) systolic dysfunction (ejection fraction 35%) and electrical dyssynchrony, demonstrated by a surface qrs duration of 120 ms. patients undergoing treatment with crt have shown significant improvement in functional class, quality of life, lv ejection fraction (ef), exercise capacity, hemodynamics, and reverse remodeling of lv, and ultimately, morbidity and mortality. however, 30%40% of patients who receive a crt device may not show improvement, and they are termed as nonresponders. the reasons for being a nonresponder are numerous and include, but are not limited to, scar burden and distribution, lv stimulation site, and limited electrical dyssynchrony.1,2 considering the risks and costs associated with implantation of a crt device, and that nonresponders have a poor prognosis, several methods have been developed to try to enhance response to crt. echocardiography - guided optimization of atrioventricular (av) delay and interventricular (vv) delay between the lv and right ventricle (rv) was enthusiastically used to guide device programming. unfortunately, though, echocardiography optimization (echo) has not resulted in significant clinical benefit because it is a time - consuming, resource - draining process and the parameters measured were often at rest with the patient in supine position.3 an ideal optimization strategy would provide continuous monitoring and adjustment of device pacing to provide maximal cardiac resynchronization, under a multitude of physiologic states. another important observation in device trials is that in the presence of intact av conduction, lv dysfunction, and a narrow qrs, rv pacing results in deleterious effects due to pacing - induced dyssynchrony with subsequent increase in hf events and deterioration in left ventricular ejection fraction (lvef).4 to date, the primary therapy of crt has been simultaneous biv pacing (ie, vv delay of 0) ; however, in the setting of intact av conduction, this programming of crt results in delivery of rv pacing, and thus substitutes intrinsic rv activation with rv - paced activation. replacing intrinsic activation of the rv with paced activation of the rv, even in the setting of biv pacing, may result in an adverse effect on cardiac performance. with this physiology, adaptive crt (acrt) is a novel device - based algorithm that was designed to achieve patient - specific adjustment in crt so as to provide appropriate biv pacing or lv - only pacing.58 this article will review the goals of crt optimization, and implementation and outcomes associated with acrt. recognizing that up to 40% of patients fail to respond to crt, there are numerous studies that have assessed methods to optimize response to biv pacing, including lead position and echocardiography - guided programming of av and vv intervals. rossillo evaluated 233 consecutive patients with new york heart association (nyha) class iii iv hf and lvef 200 ms, or the ap - rvs > 250 ms, and the heart rate is > 100 bpm, then adaptive biv pacing is delivered. if adaptive lv pacing is selected, then the lv will pace at either 70% of the measured av interval (as - rvs / ap - rvs interval) or 40 ms before intrinsic a - rvs interval, whichever value is smaller. if adaptive biv pacing is delivered, then biv pacing will be 30 ms after the end of p - wave or 50 ms before intrinsic a - rvs interval, whichever is smaller. the interventricular pacing delay (vv timing) during biv pacing is calculated based on a - rvs as well as rvs - qrs end intervals. however, if the qrs is > 160 ms, then biv-0 (simultaneous delivery of current to the rv and lv leads) pacing will be selected. with these three steps, the goal of acrt is to continuously measure the av interval utilizing rv sensing (figure 1).8 if right atrium to rv conduction is intact and normal, as represented by av node + right bundle conduction, the algorithm provides lv - only pacing. in this manner, lv pacing is synchronized to rv native activation to produce fusion with native right bundle activation. since electrical conduction, particularly via the av node, is dynamic, the av delay is adjusted to produce optimal fusion with intrinsic activation. in this manner, the rv will be activated via intrinsic conduction, which averts the adverse physiology and dyssynchrony related to rv pacing. in the circumstances when av conduction is poor, then biv-0 pacing is provided with electrical stimulation based on optimizing av delay, utilizing timing from the end of the p - wave. this acrt algorithm is suspended during any sustained atrial or ventricular tachycardia, and is not applicable in the setting of complete heart block or av junction ablation. unpublished data about the accuracy of the automatic and manual measurement of the previously mentioned waves and intervals showed a mean error of 7 ms only in p - wave measurement (medtronic inc., personal communication, october, 2015). av conduction interval is measured every minute by extending the av delay to 300 ms for one beat. the timing is from either atrial sensed or atrial paced event to rv sensing (as - rvs or ap - rvs). the p - wave conduction timing is measured from atrial sensing to the end of p - wave on the far - field atrial electrogram (a - pend). the qrs duration is measured from rvs to the end of qrs on the far - field electrogram (rvs - qrsend). from these measurements, the p - wave interval and qrs duration if the sensed av interval, as - rvs, is 200 ms, or if the paced av delay (ap - rvs) is 250 ms, and heart rate is 200 ms, or the ap - rvs > 250 ms, and the heart rate is > 100 bpm, then adaptive biv pacing is delivered. if adaptive lv pacing is selected, then the lv will pace at either 70% of the measured av interval (as - rvs / ap - rvs interval) or 40 ms before intrinsic a - rvs interval, whichever value is smaller. if adaptive biv pacing is delivered, then biv pacing will be 30 ms after the end of p - wave or 50 ms before intrinsic a - rvs interval, whichever is smaller. the interventricular pacing delay (vv timing) during biv pacing is calculated based on a - rvs as well as rvs - qrs end intervals. if the qrs is > 160 ms, then biv-0 (simultaneous delivery of current to the rv and lv leads) pacing will be selected. with these three steps, the goal of acrt is to continuously measure the av interval utilizing rv sensing (figure 1).8 if right atrium to rv conduction is intact and normal, as represented by av node + right bundle conduction, the algorithm provides lv - only pacing. in this manner, lv pacing is synchronized to rv native activation to produce fusion with native right bundle activation. since electrical conduction, particularly via the av node, is dynamic, the av delay is adjusted to produce optimal fusion with intrinsic activation. in this manner, the rv will be activated via intrinsic conduction, which averts the adverse physiology and dyssynchrony related to rv pacing. in the circumstances when av conduction is poor, then biv-0 pacing is provided with electrical stimulation based on optimizing av delay, utilizing timing from the end of the p - wave. this acrt algorithm is suspended during any sustained atrial or ventricular tachycardia, and is not applicable in the setting of complete heart block or av junction ablation. unpublished data about the accuracy of the automatic and manual measurement of the previously mentioned waves and intervals showed a mean error of 7 ms only in p - wave measurement (medtronic inc., personal communication, october, 2015). the primary study investigating acrt was by martin, published in 2012.13 this was a prospective, multicenter, randomized, double - blind, noninferiority trial comparing outcomes of acrt algorithm programmed on versus simultaneous biv pacing optimized by echocardiography. the study randomized 478 patients with hf who met criteria for de novo crt system (nyha class iii or iv symptoms, lvef 35%, and qrs 120 ms). vv timing was guided by aortic velocity time integral (aovti), to measure stroke volume, and av optimization by the iterative method. patients were then randomized in a 2:1 manner to chronic pacing using acrt versus echo. study follow - up was at 1, 3, and 6 months and then every 6 months thereafter. there were three primary end points at 6 months : 1) the clinical composite score (ccs) an aggregate measure of death, hospitalization, and change in nyha class, and patients were classified as improved, unchanged, or worsened ; 2) the concordance correlation coefficient (ccc) between the aovti values measured for each patient under echo - optimized and acrt exceeded 0.82 both at randomization and at 6-month post - randomization ; and 3) safety of the ambulatory acrt algorithm. safety was defined as no more than 60 ms variance of the av or vv delays throughout a 28-day period. if all primary end points were met, secondary end points were analyzed including : reduction of rv pacing in the acrt arm, death, hf hospitalization, ventricular arrhythmias, changes in lv end - systolic volume index, lvef, nyha classification, 6-minute hall walk distance, and quality of life. the percentage of patients who improved in the ccs at 6 months was 73.6% for acrt versus 72.5% for echo (figure 2 ; noninferiority p<0.0007) ; the ccc at ran - domization and at 6-month follow - up was high, 0.93 and 0.90, respectively (figure 3) ; and acrt did not result in inappropriate device settings. during a mean follow - up of 9.7 months, there were no differences in mortality or hf events and no difference in time to first occurrence of hf or of ventricular arrhythmias between the study groups. nearly all ventricular pacing was biv, whereas in the acrt group, median of the occurrence of biv pacing was 51% and the remainder was lv - only pacing, with a 44% reduction in rv pacing. the first study compared the treatment arm of acrt (n=266) to a pooled historical control (hc) group (n=485) derived from the crt arms of four clinical trials (miracle, miracle icd, prospect, and insync iii marquis), which each provided biv-0 pacing.14 the study end point was to assess change in the ccs at 6-month follow - up. patients in the hc underwent echocardiography - guided av optimization. the adjusted absolute difference (in percent) improved in ccs between the acrt and hc arms was 11.9% (95% confidence interval [ci ] : 2.7%19.2%) favoring acrt, and acrt patients were significantly more likely to have an improved ccs when compared to hc (odds ratio [or ] = 1.65, 95% ci : 1.12.5) (figure 4). the implication from this study is that acrt is better, rather than noninferior, to echo - guided av optimization. in the second post hoc analysis, patient outcomes in the acrt trial were correlated to percent of synchronized lv pacing.12 outcomes were also compared in the acrt group versus control patients (biv-0 pacing) stratified by intrinsic av interval. when synchronized lv pacing was 50% in the acrt group (n=142/314, 45%), there was a significant reduction in risk of death or hf hospitalization (hazard ratio [hr ] 0.49 ; 95% ci 0.280.85 ; p=0.012) compared to when synchronized lv pacing was < 50% (figure 5). also, in the patients with normal av conduction (n=241), the risk of hf hospitalization was lower in those patients treated with acrt rather than biv-0 (hr 0.52 ; 95% ci 0.270.98 ; p=0.044). this study concluded that a greater degree of synchronized lv pacing and acrt in patients with normal av intervals were independently associated with improved clinical outcomes. starling completed a prospective evaluation of the original acrt study population, assessing hospitalization for hf and for all causes with readmission within 30 days.15 he mean follow - up was 20.2 months, far greater than the 9.7-month follow - up in the original acrt study. for hf hospitalizations, the 30-day readmission rate was 19.1% (17 of 89) in the acrt group and 35.7% (15 of 42) in the echo group (biv-0 pacing) (or 0.41 ; 95% ci 0.190.86 ; p=0.02) (figure 6). for all - cause hospitalization, the 30-day readmission rate was 14.8% (35 of 237) in the acrt group compared with 24.8% (39 of 157) in the echo group (or 0.54 ; 95% ci 0.310.94 ; p=0.03). the conclusion was that acrt therapy was associated with a significant reduction in 30-day readmission after both hf and all - cause hospitalizations. modifying electrical activation of the heart with crt has been demonstrated to be successful at enhancing cardiac performance. yet, this field is still young and the ideal methods for electrical stimulation are unclear. an initial approach for optimization utilized echocardiography to guide electrical events by measuring changes in mechanical activation. yet this technique has modest benefit. another attempt to improve electrical stimulation is with electrocardiographic optimization, but this is limited by variable response and is a one - time device programming. the algorithm was designed to provide device - based, continuous assessment and automated dynamic alteration of electrical events. the basic premise is to avoid rv pacing in patients with normal av and right bundle conduction, and in this manner provide only the required therapy, synchronized lv stimulation, to help correct delayed left bundle activation. adaptive crt, therefore, is another step toward favoring lv stimulation.16 although clinical trials to date demonstrate improved outcomes, including mortality, with acrt, the entirety of the findings is based upon one randomized trial. also, acrt is only applicable in ~40% of recipients of crt, since it requires sinus rhythm, and intact av node and right bundle conduction. before embracing and building upon acrt as the foundation for a new direction of electrical stimulation for hf, larger multicenter, randomized trials are necessary to not only confirm the benefits of acrt, but also to compare acrt to lv - only pacing. we also need to keep in mind the financial impact of the newer technology in crt including adaptive crt. the cost of the acrt device compared to the nonadaptive crt device is slightly higher. | cardiac resynchronization therapy (crt) is an effective and well - established therapy for patients suffering with heart failure, left ventricular (lv) systolic dysfunction (ejection fraction 35%), and electrical dyssynchrony, demonstrated by a surface qrs duration of 120 ms. patients undergoing treatment with crt have shown significant improvement in functional class, quality of life, lv ejection fraction, exercise capacity, hemodynamics, and reverse remodeling of lv, and ultimately, morbidity and mortality. however, 30%40% of patients who receive a crt device may not show improvement, and they are termed as non responders. the nonresponders have a poor prognosis ; several methods have been developed to try to enhance response to crt. echocardiography - guided optimization of crt has not resulted in significant clinical benefit, since it is done at rest with the patient in supine position. an ideal optimization strategy would provide continuous monitoring and adjustment of device pacing to provide maximal cardiac resynchronization, under a multitude of physiologic states. intrinsic activation of the right ventricle (rv) with paced activation of the rv, even in the setting of biventricular (biv) pacing, may result in an adverse effect on cardiac performance. with this physiology, the use of lv - only pacing may be preferred and may enhance crt. adaptive crt is a novel device - based algorithm that was designed to achieve patient - specific adjustment in crt so as to provide appropriate biv pacing or lv - only pacing. this article will review the goals of crt optimization, and implementation and outcomes associated with adaptive crt. |
a 22-year - old, stuporous, but previously healthy man, 182 cm in height and 70 kg in weight, was admitted to the emergency room with an accidental injury from a fall. an emergent brain ct demonstrated acute traumatic subdural hematoma, thus an emergent decompressive craniectomy and hematoma removal was performed under general anesthesia without any remarkable incidences. after the first operation, the patient had not made favorable progresses, therefore several further operations such as brain abscess drainage, external ventricular drainage catheter insertion, cerebral lobectomy, ventriculoperitoneal shunt were performed during a 4 month period. the vital signs of the patient scheduled for cranioplasty were a systolic / diastolic blood pressure of 110/70 mmhg, heart rate 104 bpm, respiratory rate via tracheostomy 20 /min and the patient was still in a stuporous state. preoperative laboratory data were within the normal range, and the chest x - ray revealed improvement of focal pneumonia and an arterial blood gas analysis in the tolerable range (abga ; ph 7.418/paco2 39.5 mmhg / pao2 104 mmhg with 2 l / min oxygen inhalation). an electrocardiogram (ecg) performed before the surgery showed sinus tachycardia, and transthoracic echocardiography revealed a preserved global left ventricular systolic function (ejection fraction ; 69%). the preoperative brain ct sacn showed a marked shrinkage of the left cerebral hemisphere and an increase in ventricular size (fig. the general anesthesia was induced with 125 mg thiopental sodium and 50 mg rocuronium, without any premedication. the vital signs were monitored using noninvasive blood pressure (nibp), ecg and a pulse oximeter. the tracheostomy tube was changed for a 7.5 mm cuffed tracheostomy tube. following the induction of anesthesia, the right dorsalis pedis artery was cannulated with a 22 gauge catheter, and the right femoral vein was cannulated with an 18 gauge catheter. general anesthesia was maintained with balanced anesthesia using oxygen - air - sevoflurane (0.51.5%) and supplementary remifentanil (46 g / kg / h) infusion. cranioplasty was carried out under controlled ventilation, keeping within 10% fluctuation of the vital signs and etco2 with intermittent injections of ephedrine, phenylephrine and esmolol. the abga was checked immediately after skin incision, and the results were a ph of 7.436, paco2 35.1 mmhg, pao2 219.1 mmhg, and base excess 0.5. intravenous fluid replacement consisted of 500 ml plasma solution and 50 ml lactated ringer solution, and the estimated blood loss was 200 ml. after 2 hours of operation, the dura was closed, and the bony fragment was wired into place. subsequently, drainage catheters were introduced into both the subgaleal and epidural spaces. by the time the scalp sutures were completed, a closed negative approximately 30 seconds after suction drainage, sudden asystole of ecg, the disappearance of etco2 wave and a flat line arterial wave form were noticed. instantly, the suction drainage was stopped, and we started external cardiac massage for approximately 20 seconds. two times injections of 500 g epinephrine were administered under the diagnosis of cardiac arrest. the cardiac rhythm was resumed to 120 bpm, and systolic blood pressure was regained to 150 mmhg immediately. the abga was checked after resuscitation, and the results were in the normal range (ph 7.418, paco2 39.5 mmhg, pao2 103.3 mmhg and base excess 0.2). he went into a coma and showed partial spastic movement of extremities, suggesting a sudden increase in intracranial pressure (icp). 2) revealed extensive diffuse brain swelling. due to the fact that there were no specific causes of brain edema during the operation or general anesthesia, the negative vacuum suction drainage was presumed to be the main cause, resulting in the patient being diagnosed with phbs. the patient received agents to reduce icp, in addition to general supportive care with controlled ventilation. he improved gradually in the nicu, and reached a stuporous state with self - respiration 3 months postoperatively. van roost. reported phbs as a newly defined complication after uneventful brain surgery. the main clinical characteristic that appear on brain ct scans include brainstem dysfunction and diffuse brain swelling, especially involving the bilateral basal ganglia and thalami. the main pathomechanism of phbs is assumed to be a decrease in icp due to sudden excessive depletion of cerebrospinal fluid (csf). an increase in icp can cause the cushing response, characterized by the occurrence of hypertension, bradycardia, and respiratory irregularities, resulting from the stimulus of pressure on the brainstem. the opposite of the cushing response, intracranial hypotension, is also though to be a possible cause of circulatory changes such as bradycardia, hypotension and even cardiac arrest. it is known that intracranial hypotension, induced by an extradural suction drainage system for the prevention of postoperative hematoma formation, may occur in neurosurgical procedures. this iatrogenic intracranial hypotension may develop during or after variable neurosurgical procedures when applying negative suction pressure to extradural or epicranial drainage after craniotomy, after sudden decompression of hydrocephalus, or after spine surgery related to csf loss during the operation. because the burr hole trephination and cranial bone incisions are not water proof, negative pressure subgaleal suction may provoke acute loss of the csf and a decrease in icp. a rapid fatal case has been reported following a drainage volume of 100-ml csf. however, a small loss of csf by gravity can cause phbs. after a loss of csf, the brain can expand to fill up free space that was previously filled with gas and fluid including csf and exsanguinated blood. the pathomechanism of bradycardic rhythm disturbances following intracranial hypotension was reported as a consequence of rostral migration of the brain or brainstem. the pressure changes of the brainstem and hypothalamus can be caused by alteration of sympathetic outflow to induce lethal bradycardia, hypotension, or both. in the present case, firstly, there were no specific events during the entire anesthesia or operation, however, sudden severe bradycardia and cardiac standstill were noticed immediately after initiation of suction drainage through the subgaleal and epidural catheter. the exact amount of csf was not calculated. secondly, the postoperative brain ct scan showed diffuse brain swelling. this patient already had shrunken brain hemispheres and a widened intraventricular space, and the negative suction pressure increased the free space after cranioplasty and could evoke a more diffuse brain swelling. we could postulate that this was the reason why severe phbs happened in this case. in conclusion, unexpected circulatory collapses such as hypotension, severe bradycardia, and cardiac arrest can develop following intracranial hypotension due to loss of csf through the negative suction drainage in variable neurosurgical procedures. anesthesiologists and neurosurgeons should consider, be alert, and cope with potential perioperative circulatory collapses or clinical deteriorations related to phbs following intracranial hypotension in uneventful brain surgery. | pseudohypoxic brain swelling (phbs) is known to be an uncommon event that may occur during and following an uneventful brain surgery, when negative suction drainage is used. the cerebrospinal fluid loss related to suction drainage can evoke intracranial hypotension that progress to phbs. the main presentations of phbs are sudden unexpected circulatory collapses, such as severe bradycardia, hypotension, cardiac arrest, consciousness deterioration and diffuse brain swelling as seen with brain computerized tomography (ct). we present a stuporous 22-year - old patient who underwent cranioplasty under general anesthesia. the entire course of the general anesthesia and operation progressed favorably. however, the time of scalp suture completion, sudden bradycardia and hypotension occurred, followed by cardiac arrest immediately after initiation of subgaleal and epidural suction drainage. after successful resuscitation, the comatose patient was transferred to the neurosurgical intensive care unit and phbs was confirmed using brain ct. |
hysterectomy remains the most common major gynecological operation and may be carried out by 3 different routes : vaginal, abdominal, and laparoscopic. clearly, indications for these 3 routes should differ, but they can also overlap. although the abdominal route is unanimously considered the most morbid hysterectomy procedure, the vaginal route appears to be the quickest and the least expensive when it can be safely conducted. however, with increases in uterine weight the vaginal route becomes more difficult, especially in nulliparas, and in these patients, the laparoscopic route may allow for a laparotomy to be avoided. nevertheless, it should be noted that in more than 1,000 publications on laparoscopic hysterectomy, opinion concerning its role is greatly divided. although many enlarged uteri can be delivered vaginally by skilled surgeons, the procedure is not always quick and safe. in patients with enlarged uteri, blood loss may be considerable, especially when extended time is required to morcellate the uterus, leading to unavoidable retrograde bleeding. laparoscopic hysterectomy can be a valid surgical approach in these cases, though it may be useful to modify several stages of the classical procedure to make it safer. the laparoscopic approach allows the interruption of blood supply before uterine procedures and the beginning of uterine morcellation. the aim of our study was to describe the total laparoscopic hysterectomy technique using primary uterine devascularization and to report outcomes for a series of women with enlarged uteri benign pathology who benefited from this procedure. total laparoscopic hysterectomy is preceded by a 7-day free - residue diet, to diminish intraabdominal volume taken up by intestinal loops. in cases where uterus weight is estimated at more than 800 g to 1,000 g (range, 1.8 to 2.2 lb), an injection of 11.75 mg leuprorelin lp is administered 3 months before surgery, with the aim of reducing both uterine volume and vascularization. the keys to a successful procedure are the upward trocar sites that depend solely on uterine size, the complete devascularization of the uterus before any other surgical procedure is performed on the uterus, and its appropriate fragmentation which allows sectioning of the uterine pedicles close to the uterus, bladder dissection, and decreases both the duration and difficulty of the vaginal stage. to these could be added the previous free - residue diet that further guarantees safety and intraoperative convenience and the strong mobilization of the uterus by use of a uterine manipulator. the clermont ferrand type uterine manipulator, commercialized by karl storz gmbh & co (tuttlingen, germany), is used to allow lateral mobilization of the uterus by a third surgeon positioned between the patient 's legs. in most cases, 2 ancillary 12-mm trocars are placed on the umbilicus and 8 cm above and 2 ancillary 5-mm trocars are placed on the 2 sides of the umbilicus, at 8 cm to 10 cm laterally. the first stage, performed at the onset of the surgical procedure, is complete uterus devascularization, by coagulating both uterine arteries at the artery origin and infundibulo - pelvic ligaments or utero - ovarian vessels. the second operator grasps and tracks the umbilical artery upwards, and the third operator carries out uterine contralateral mobilization. the peritoneum is opened on the anterior leaf of the broad ligament, parallel to the infundibulo - pelvic ligament, along the umbilical artery and above the crossing with the external iliac artery. the superior bladder artery is crossed, and care should be taken to avoid confusion with the uterine artery, which is situated 1 cm to 2 cm further back. the uterine artery origin is then revealed and the pararectal space opened making the ureter easy to identify. the uterine artery is coagulated, using bipolar current, at its origin from the internal iliac artery (figure 1), while the ureter is carefully pushed medially to avoid electrical injury. devascularization is accomplished by the coagulation and section of either ovarian (if adnexectomy is performed) or utero - ovarian vessels. the left uterine artery is coagulated at its origin with bipolar current (uta left uterine artery ; uma left umbilical artery). the next stage of the laparoscopic hysterectomy involves reducing the volume of the uterus either by uterine bisection or multiple myomectomies, using a laparoscopic cold knife, a monopolar current hook (40 w) or a harmonic scalpel (ethicon endo surgery, issy - le - moulineaux, france). this stage does not require coagulation, as only venous blood retained in the uterus is lost. however, this procedure may take 40 minutes to 60 minutes in cases where morcellating the uterus is impeded by hard myomas or adenomyosis. the bladder flap is opened using bipolar coagulation forceps, scissors, or a harmonic scalpel. the patient 's position is altered to allow for the retrieval of uterine fragments using the vaginal approach, the procedure taking up to 30 minutes to 40 minutes, depending on the efficiency of the laparoscopic uterine fragmentation. women who underwent a laparoscopic hysterectomy performed with the technique described above, between december 26, 2005 and march 7, 2007 in our department, and who had a uterus weighing more than 280 g, were retrospectively included in the study. the 280 g cutoff corresponds to the superior limit recommended by the american college of obstetricians and gynecologists (acog) for the vaginal route (approximately 12-weeks ' gestational size or 280 g). the following patient characteristics were provided by medical chart : age, weight, height, body mass index (bmi), parity, delivery route (vaginal or cesarean), pelvic surgical antecedents, menopausal status, hormonal substitutive treatment, reasons for the hysterectomy, the duration of the procedure, the volume of co2 insufflated, other surgical gestures associated with the hysterectomy and uterus weight, histological examination results, duration of the hospitalization, and postoperative complications. in accordance with french law continuous variables are expressed as mean sd, median (quartiles and range), and qualitative variables as number (percentages). the relationship between uterine weight and duration of the surgical procedure was estimated using the correlation coefficient r. total laparoscopic hysterectomy is preceded by a 7-day free - residue diet, to diminish intraabdominal volume taken up by intestinal loops. in cases where uterus weight is estimated at more than 800 g to 1,000 g (range, 1.8 to 2.2 lb), an injection of 11.75 mg leuprorelin lp is administered 3 months before surgery, with the aim of reducing both uterine volume and vascularization. the keys to a successful procedure are the upward trocar sites that depend solely on uterine size, the complete devascularization of the uterus before any other surgical procedure is performed on the uterus, and its appropriate fragmentation which allows sectioning of the uterine pedicles close to the uterus, bladder dissection, and decreases both the duration and difficulty of the vaginal stage. to these could be added the previous free - residue diet that further guarantees safety and intraoperative convenience and the strong mobilization of the uterus by use of a uterine manipulator. the clermont ferrand type uterine manipulator, commercialized by karl storz gmbh & co (tuttlingen, germany), is used to allow lateral mobilization of the uterus by a third surgeon positioned between the patient 's legs. in most cases, 2 ancillary 12-mm trocars are placed on the umbilicus and 8 cm above and 2 ancillary 5-mm trocars are placed on the 2 sides of the umbilicus, at 8 cm to 10 cm laterally. the first stage, performed at the onset of the surgical procedure, is complete uterus devascularization, by coagulating both uterine arteries at the artery origin and infundibulo - pelvic ligaments or utero - ovarian vessels. the second operator grasps and tracks the umbilical artery upwards, and the third operator carries out uterine contralateral mobilization. the peritoneum is opened on the anterior leaf of the broad ligament, parallel to the infundibulo - pelvic ligament, along the umbilical artery and above the crossing with the external iliac artery. the superior bladder artery is crossed, and care should be taken to avoid confusion with the uterine artery, which is situated 1 cm to 2 cm further back. the uterine artery origin is then revealed and the pararectal space opened making the ureter easy to identify. the uterine artery is coagulated, using bipolar current, at its origin from the internal iliac artery (figure 1), while the ureter is carefully pushed medially to avoid electrical injury. devascularization is accomplished by the coagulation and section of either ovarian (if adnexectomy is performed) or utero - ovarian vessels. the left uterine artery is coagulated at its origin with bipolar current (uta left uterine artery ; uma left umbilical artery). the next stage of the laparoscopic hysterectomy involves reducing the volume of the uterus either by uterine bisection or multiple myomectomies, using a laparoscopic cold knife, a monopolar current hook (40 w) or a harmonic scalpel (ethicon endo surgery, issy - le - moulineaux, france). this stage does not require coagulation, as only venous blood retained in the uterus is lost. however, this procedure may take 40 minutes to 60 minutes in cases where morcellating the uterus is impeded by hard myomas or adenomyosis. the bladder flap is opened using bipolar coagulation forceps, scissors, or a harmonic scalpel. the patient 's position is altered to allow for the retrieval of uterine fragments using the vaginal approach, the procedure taking up to 30 minutes to 40 minutes, depending on the efficiency of the laparoscopic uterine fragmentation. women who underwent a laparoscopic hysterectomy performed with the technique described above, between december 26, 2005 and march 7, 2007 in our department, and who had a uterus weighing more than 280 g, were retrospectively included in the study. the 280 g cutoff corresponds to the superior limit recommended by the american college of obstetricians and gynecologists (acog) for the vaginal route (approximately 12-weeks ' gestational size or 280 g). the following patient characteristics were provided by medical chart : age, weight, height, body mass index (bmi), parity, delivery route (vaginal or cesarean), pelvic surgical antecedents, menopausal status, hormonal substitutive treatment, reasons for the hysterectomy, the duration of the procedure, the volume of co2 insufflated, other surgical gestures associated with the hysterectomy and uterus weight, histological examination results, duration of the hospitalization, and postoperative complications. in accordance with french law continuous variables are expressed as mean sd, median (quartiles and range), and qualitative variables as number (percentages). the relationship between uterine weight and duration of the surgical procedure was estimated using the correlation coefficient r. the procedure described above was used in more than 50 women with benign uterine pathologies, rectovaginal and rectal endometriosis, endometrial cancer, or pelvic inflammatory diseases. of them, patient characteristics and data related to surgical procedure and outcomes (n = 18) one woman was postmenopausal, with no hormonal substitution, and 2 patients had previously had cesarean deliveries (11%). the patients ' complaints were abnormal bleeding in 13 cases (72%), pelvic pain in 8 cases (44%), and bladder and bowel symptoms due to increased uterine volume in 4 cases (22%). the duration of the surgical procedure ranged from 90 minutes to 260 minutes (median, 185), and the duration of the devascularization procedure (involving identification of the umbilical ligament, coagulation of the uterine artery and coagulation of either the ovarian or utero - ovarian artery) averaged 10 minutes per side (range, 5 to 20). the 3 longest operative times were due to additional procedures : resection of deep posterior endometriosis in 2 cases (11%) and extensive adhesiolysis in 1 case (6%). the correlation coefficient r was -0.15 (p=0.56) (figure 2), showing that the duration of the intervention was not related to uterine size, but mainly due to the necessity to perform associated procedures and to the duration of the uterine fragmentation stage. correlation between uterine weight and length of surgical procedure (n=18, correlation coefficient r=-0.15, p=0.56). histopathologic analysis revealed myomas in 15 cases (83%) and adenomyosis in 3 patients (17%). no intraoperative complications (bleeding, digestive, or urinary injuries) or major approach difficulties were noted. women participating in the study were managed by 4 surgeons, one who (hr) generally carries out laparoscopic hysterectomies and 3 others (lm, br, el) who usually perform vaginal hysterectomies even in uteri exceeding 280 g. throughout the study period, only 2 women meeting the inclusion criteria had abdominal hysterectomies performed by the same surgeon (br), justified respectively by the size of the uterus (more than 2300 g) and extended deep endometriosis in a woman with a 510 g uterus. this technique is feasible and reproducible by gynecological surgeons and avoids the use of laparotomy in enlarged uteri. in our department, one surgeon began using the technique, and subsequently it was acquired and easily reproduced by others. approaching the origin of the uterine artery is possible despite uterine size and is feasible for surgeons skilled in pelvic lymph node dissection. in our opinion, the key to a successful procedure is the performance of uterine devascularization before initiating further uterine surgical actions. an obvious color change of the uterus indicates that the classical procedure of laparoscopic or vaginal hysterectomy can then be safely begun. this technique also includes opening of the pararectal space and allows separation of the ureter from the uterine artery, enabling coagulation to be safely accomplished under direct visual control. from this stage although surgeons may prefer the vaginal route, the primary laparoscopic coagulation of the uterine artery at the artery origin allows for a safer vaginal hysterectomy when the uterus is particularly enlarged. in our study, the median procedure time was 185 minutes, with longer operating times in women with associated pelvic pathologies like endometriosis. longer operative times also occurred in cases of large uteri due to adenomyosis, which impeded fragmentation. uterine fragmentation represented the longest stage of this procedure, and research is being pursued to find ways of making this both quicker and easier, with the possible use of morcellators. the duration of the procedure in our series is comparable to those of several authors who have reported total laparoscopic hysterectomies in enlarged uteri, but is longer than that of kohler who exclusively carry out vaginal morcellation. it should be noted that our rate of obese women is low. during the research period, hysterectomies were not performed in morbidly obese women meeting inclusion criteria, but high bmi can increase both procedure duration and intraoperative difficulties. similarly, in one case where extensive adhesiolysis was required, the operative time increased to 250 minutes. adhesions are a well - known risk factor for complications and conversion to the abdominal route and particular care is needed in these situations. abdominal hysterectomy was carried out in one woman whose uterus weighed 2300 g. although devascularization can be performed in very enlarged uteri by using two 12-mm trocars in both the right and left upper quadrants, the fragmentation and retrieval of the uterus by the above described technique would be excessively long and challenging. with regard to patient inclusion criteria, a uterus weight cutoff was chosen of 280 g as vaginal hysterectomy appears to be the fastest, cheapest, and least morbid surgical route in small and moderately large uteri. we are in agreement with several studies that show that the laparoscopic route does not provide a significant benefit in uteri weighing less than 280 g representing the majority of cases in daily practice. this cutoff is higher for surgeons skilled in the vaginal route who are able to remove the majority of uteri transvaginally regardless of size. however, in uteri weighing more than 500 g to 600 g, the vaginal route presents difficulties particularly amongst nulliparas. although laparoscopic hysterectomy has now existed for 18 years, its place has not yet been established, and it is routinely carried out by a small number of gynecological surgeons. this situation may be the result of controversial discussions between defenders of either the vaginal or laparoscopic route in hysterectomy, who have tended to point out the weaknesses of the other approach rather than focusing on specific indications for their own technique. in addition, most surgeons are not trained in both techniques and are likely to defend the approach that they master the best. as a conclusion to their systematic review, johnston stated that no evidence supports the use of laparoscopic hysterectomy as opposed to vaginal hysterectomy if the latter can be done safely. this statement in our opinion is not unfavorable to the laparoscopic procedure, as surgeons can choose to either carry out a vaginal hysterectomy where they feel it is feasible or to perform the laparoscopic route in other cases. in these other cases, the above - described technique is useful as it may protect against unexpected intraoperative hemorrhage requiring conversion to the abdominal route, and it provides optimal protection for the ureter. however, to be able to carry out a laparoscopic hysterectomy in enlarged uteri, surgeons should previously perform this procedure in small uteri, namely in uteri where vaginal delivery appears to be the best choice. surgeons should be aware that performing vaginal hysterectomy whenever it can be done safely must not lead to inadequate training in laparoscopic hysterectomy. the selective coagulation of the uterine artery at its origin is a reproducible technique that allows safe total laparoscopic hysterectomy in enlarged uteri. this procedure avoids unexpected perioperative hemorrhage requiring conversion to the abdominal route and provides optimal protection for the ureter. | background : to argue the usefulness for performing total laparoscopic hysterectomy with primary uterine artery coagulation at its origin for a series of women presenting with an enlarged benign uterus.method:eighteen women having undergone the procedure consecutively during a period of 17 months were studied retrospectively. the inclusion criteria were an enlarged benign uterus weighing more than 280 g, managed by total laparoscopic hysterectomy with primary uterine artery coagulation at its origin.results:patient median values (range) for age, body mass index, and parity were respectively 47.5 years (range, 38 to 53), 25 kg / m2 (range, 19.3 to 34.9), and 2 (range, 0 to 3). the median value for uterine weight (range) was 540 g (range, 280 to 1,015), and the median duration for the surgical procedure was 185 minutes (range, 90 to 260), the longest procedures being due to associated deep endometriosis resection and extensive adhesions. the duration of the intervention was not significantly correlated with uterine size (correlation coefficient r=-0.15, p=0.56), and no intra- or postoperative complications were recorded.conclusion:the selective coagulation of the uterine artery at its origin is a reproducible technique that allows total laparoscopic hysterectomy in enlarged uteri. this procedure avoids unexpected intraoperative hemorrhage requiring conversion to the abdominal route and provides optimal protection for the ureter. |
oesophageal perforations are associated with high morbidity and mortality, predominantly as a result of a mediastinal leakage frequently leading to septic shock. we report a patient on warfarin therapy presenting an intramural, intrathoracic eosophageal haematoma prior to oesophagus perforation ; a condition that to our knowledge is not previously reported. in our patient, an initial conservative approach was used in managing the haematoma and once perforated prompt surgical intervention was initated. a 84-year - old women presented to the emergency room after she slipped and fell causing blunt traumas to the chest and face. she was conscious, hemodynamically stable and had normal blood counts besides a low albumin of 34 g / l (3445 the patient was on warfarin treatment due to atrial fibrillation and a history of pulmonary embolisms, and suffered furthermore from recurrent urinary tract infections and pulmonary fibrosis. initial computed tomography (ct) revealed a 4 cm 6 cm 15 cm paraoesophageal haematoma located in the superior and posterior mediastinum (fig. initially the haematoma was treated conservatively but during the course of hospitalization the patient developed increasing difficulty swallowing and on the 18th day, the patient 's condition rapidly deteriorated with fever, tachycardia, acidosis and leukocytosis. an immediate ct scan showed mediastinal leakage corresponding the known location of the haematoma (fig. 2). due to mediastinal leakage and unknown consequences of stent - treating a haematoma of this size this revealed no intra- or extramural necrosis but an extremely tense haematoma and further confirmed a 3 cm longitudinal oesophageal perforation. the perforation was directly sutured ; no reinforcements were applied. until recognition of the perforation the patient was on proton pump inhibitors and soft diet, and during the post - op stay antibiotics and parenteral nutrition. the patient began full diet 10 days prior to discharge. due to a complicated post - op stay with fungal and bacterial infection we report an intramural, intrathoracic esophageal haematoma with late rupture as a result of blunt trauma to the chest. earlier cases describe intramural small bowel haematomas in patients using warfarin but our case is extremely rare. our patient 's single complaint was chest pain and although anticoagulant therapy was discontinued, late complications to haematomas are possible. likely, the perforation might be due to ischemia from the pressure built up between the haematoma, vena azygos and the distal trachea ; or the oesophageal rupture was immediate present after the trauma and the haematoma walled it off until the patient became symptomatic. early diagnosis and management of oesophageal perforation is difficult but imperial in reducing morbidity and mortality. whether surgical or conservative treatment is indicated depends mainly on the general health of the patient, time elapsed and the size of the perforation. thoracic esophageal perforations are usually differentiated in those contained within the mediastinum and those noncontained that drain into the pleural space as with our patient. primary stent treatment for spontaneus esophageal perforations especially in iatrogenic perforations has proven effective but outcomes for stent treating haematomas are unknown and require close radiographic and endoscopic follow - up. as to our knowledge, no guidelines on traumatic blunt perforations with haematomas are available, and we believe as indicated by others, that stent treatment should be reserved for patients not fit to undergo major surgery like thoracotomy, or as 2nd line management in persistent leak or sepsis once a perforation is verified management should always include antibiotics, proton pump inhibitors and parenteral nutrition as vital therapeutic measures. if choosing to treate an oesophageal hematoma conservatively we advise to stop anticoagulants or lead strict control of international normalised ratio (inr) when prescribing vitamin - k - antagonists. to prevent esophageal lesions, it is advisable to refrain from gastric tubes and instead consider parenteral nutrition. as with our patient, chest pain is the most frequent symptom but other symptoms such as fever, dyspnoea and dysphagia might dominate. late, spontaneous, intrathoracic esophageal perforations due to blunt trauma is to our knowledge not described previously. such haematomas can be treated conservatively but if the esophageal wall ruptures prompt surgically management must be taken, especially if uncontained. | introductiontraumatic oesophageal perforation is a rare, life - threatening emergency that requires early recognition and prompt surgical management.presentation of casewe present an unusual case of a patient on warfarin treatment developed an intramural oesophageal haematoma following blunt thoracic trauma leading to perforation on the 18th day.discussionin treatment of oesophageal haematoma in patients on vitamin - k antagonists, strict control of the international normalized ratio (inr) is essential along with total parenteral nutrition therapy and refrainment through nasogastric tubes. three explanations postulated to be the cause for late perforation which might be due to esophageal wall ischemia from pressure built up between the hematoma, azygos vein and the lower part of thoracic trachea ; or could be an immediate rupture walled - off until the patient became symptomatic ; or the intramural hematoma gradually lysed and causing late perforation.conclusionalthough extremely rare, an oesophageal haematoma and late complications must be considered in patients on anti - coagulant therapy following blunt thoracic trauma and complaining only of chest pain. |
the incidence of intertrochanteric fractures has been increasing significantly due to the rising age of modern human populations. generally, intramedullary fixation and extramedullary fixation are the 2 primary options for treatment of such fractures. the dynamic hip screw (dhs), commonly used in extramedullary fixation, has become a standard implant in treatment of these fractures. proximal femoral nail (pfn) and gamma nail are 2 commonly used devices in the intramedullary fixation. previous studies showed that the gamma nail did not perform as well as dhs because it led to a relatively higher incidence of post - operative femoral shaft fracture. pfn, introduced by the ao / asif group in 1997, has become prevalent in treatment of intertrochanteric fractures in recent years because it was improved by addition of an antirotation hip screw proximal to the main lag screw. however, both benefits and technical failures of pfn have been reported [79 ] although the effects of pfn and dhs in treatment of intertrochanteric fractures have been reported, the results and conclusions are not consistent [1015 ]. therefore, we conducted this meta - analysis to investigate whether there is a significant difference between pfn and dhs fixation in treatment of intertrochanteric fractures. our aim was to evaluate clinical results comparing pfn with dhs, including comparison of operative time, intraoperative blood loss, length of incision, postoperative infection rate, lag screw cut - out rate, and reoperation rate. we hypothesized that pfn would be a superior treatment for intertrochanteric fractures compared with dhs. we searched for randomized or quasi - randomized controlled studies comparing the effects of pfn and dhs according to the search strategy of the cochrane collaboration. it included searching of the cochrane musculoskeletal injuries group trials register, computer searching of medline, embase, and current contents, and hand searching of orthopedic journals. the inclusion and exclusion criteria used in selecting eligible studies were : (1) target population individuals with intertrochanteric fractures, excluding subtrochanteric and pathological fractures ; (2) intervention dhs fixation compared with pfn fixation ; (3) methodological criteria prospective, randomized, or quasi - randomized controlled trials ; (4) duplicate or multiple publications of the same study were not included. data were collected by 2 independent researchers who screened titles, abstracts, and keywords both electronically and by hand ; differences were resolved by discussion. full texts of citations that could possibly be included in the present meta - analysis were retrieved for further analysis. the assessment method from the cochrane handbook for systematic reviews of interventions was used to evaluate the studies in terms of blinding, allocation concealment, follow - up coverage, and quality level. the study quality was assessed according to whether allocation concealment was : adequate (a), unclear (b), inadequate (c), or not used (d). operative time (min), intraoperative blood loss (ml), length of incision, post - operative infection, lag screw cut - out rate, and reoperation rate were the main measures in the studies included, which the present meta - analysis evaluated to compare the effects of pfn and dhs. we did not undertake a subgroup analysis for different fracture types because not all of the studies included described the fracture types. in each eligible study the relative risk (rr) was calculated for dichotomous outcomes and the weighted mean difference for continuous outcomes using the software review manager 5.0, with a 95% confidence interval (ci) adopted in both. heterogeneity was tested using both the chi - square test and the i - square test. a significance level of less than 0.10 for the chi - square test was interpreted as evidence of heterogeneity. when there was no statistical evidence of heterogeneity, a fixed - effect model was adopted ; otherwise, a random - effect model was chosen. we did not include the possibility of publishing bias due to the small number of studies included. a total of 48 articles comparing pfn and dhs that had been published from 1969 to august 2012 were retrieved : 37 were from medline, 6 from the cochrane library, and 5 from the embase library. among them, 13 trials met the inclusion criteria. after excluding non - randomized control trials and retrospective articles, 6 randomized and quasi - randomized controlled trials [1015 ] were included (figure 1). the number of fractures included in a single study ranged from 64 to 206. three research papers targeted asian patients, and the other 3 targeted caucasians. all studies except 1 had more female than male patients ; 308 fractures were managed with pfn and 361 managed with dhs. the quality of the 6 studies included was level b because the allocation concealment was unclear according to the evaluation criteria mentioned above (tables 1 and 2). four studies provided data on operative time. the random - effects model was used because of the statistical heterogeneity (i=97%). the meta - analysis indicated that the operative time for the pfn group was significantly shorter than for the dhs group (wmd : 21.15, 95% ci : 34.91 7.39, p=0.003) (figure 2). four studies provided data on intraoperative blood loss. the random - effects model was used because of the statistical heterogeneity (i=94%). the meta - analysis indicated that the intraoperative blood loss for the pfn group was significantly less than for the dhs group (wmd : 139.81, 95% ci : 210.39 69.22, p=0.0001) (figure 3). two studies provided data on length of incision. the random - effects model was used because of the statistical heterogeneity (i=91%). the meta - analysis indicated that the length of incision in the pfn group was significantly shorter than in the dhs group (wmd : 6.97, 95% ci : 9.19 4.74, p<0.00001) (figure 4). five studies [1014 ] provided data on postoperative infection rate. postoperative infection was observed in 6 of the 254 fractures managed with pfn, and in 7 of the 273 fractures managed with dhs. data pooled by a fixed - effects model and the meta - analysis indicated an insignificantly higher rate of postoperative infection in the dhs group (rr : 0.96, 95% ci : 0.332.8, p=0.94) (figure 5). lag screw cut - out was observed in 5 of the 205 fractures managed with pfn and in 7 of the 253 fractures managed with dhs. data pooled by a fixed - effects model and the meta - analysis indicated an insignificantly higher rate of lag screw cut - out in the dhs group (rr : 0.95, 95% ci : 0.302.97, p=0.92) (figure 6). reoperation was needed in 13 of the 172 fractures managed with pfn and in 7 of the 182 fractures managed with dhs. data pooled by a fixed - effects model and the meta - analysis indicated an insignificantly higher rate of reoperation in the pfn group (rr : 2.03, 95% ci : 0.795.23, p=0.14) (figure 7). four studies provided data on operative time. the random - effects model was used because of the statistical heterogeneity (i=97%). the meta - analysis indicated that the operative time for the pfn group was significantly shorter than for the dhs group (wmd : 21.15, 95% ci : 34.91 7.39, p=0.003) (figure 2). four studies provided data on intraoperative blood loss. the random - effects model was used because of the statistical heterogeneity (i=94%). the meta - analysis indicated that the intraoperative blood loss for the pfn group was significantly less than for the dhs group (wmd : 139.81, 95% ci : 210.39 69.22, p=0.0001) (figure 3). two studies provided data on length of incision. the random - effects model was used because of the statistical heterogeneity (i=91%). the meta - analysis indicated that the length of incision in the pfn group was significantly shorter than in the dhs group (wmd : 6.97, 95% ci : 9.19 4.74, p<0.00001) (figure 4). postoperative infection was observed in 6 of the 254 fractures managed with pfn, and in 7 of the 273 fractures managed with dhs. data pooled by a fixed - effects model and the meta - analysis indicated an insignificantly higher rate of postoperative infection in the dhs group (rr : 0.96, 95% ci : 0.332.8, p=0.94) (figure 5). four studies provided data on lag screw cut - out rate. lag screw cut - out was observed in 5 of the 205 fractures managed with pfn and in 7 of the 253 fractures managed with dhs. data pooled by a fixed - effects model and the meta - analysis indicated an insignificantly higher rate of lag screw cut - out in the dhs group (rr : 0.95, 95% ci : 0.302.97, p=0.92) (figure 6). three studies provided data on reoperation rate. reoperation was needed in 13 of the 172 fractures managed with pfn and in 7 of the 182 fractures managed with dhs. data pooled by a fixed - effects model and the meta - analysis indicated an insignificantly higher rate of reoperation in the pfn group (rr : 2.03, 95% ci : 0.795.23, p=0.14) (figure 7). the varus collapse of the head and neck caused by lag screw cut - out or lateral protrusion is one of most common post - operative complications that lead to surgical failure in treatment of intertrochanteric fractures. the cut - out (including z effect) rates were about 310% in pfn and dhs. most studies reported that lag screw position might be associated with the rate of cut - out in dhs fixation. cut - out was thought to be caused either by improper lag screw placement in the anterior superior quadrant of the head or by not placing the screw close enough to the subchondral region of the head. another explanation for cut - out is that because the screw is rotationally unstable within the bone when a single lag screw is used, flexion - extension of the limb results in loosening of the bone screw interface, leading to the secondary cut - out of the screw. in 1997 it was designed to overcome implant - related complications and facilitate the surgical treatment of unstable intertrochanteric fractures. biomechanical analysis of pfn showed a significant reduction of distal stress and an increase in overall stability compared with the gamma nail. despite the mechanical advantages of pfn, lag screw cut - out remains a significant problem, especially in the more unstable fractures. this meta - analysis also found a higher rate of lag screw cut - out in the dhs group, though it was not statistically significant. this indicates that the anti - rotation screw of the pfn may not be beneficial enough. however, herman. showed that the mechanical failure rate increased from 4.8% to 34.4% when the centre of the lag screw was not in the second quarter of the head - neck interface line (the so - called safe zone) (p=0.001) and that the lag screw insertions lower or higher than the head apex line by 11 mm were associated with failure rates of 5.5% and 18.6%, respectively (p=0.004). they suggested that placing the lag screw within the safe zone could significantly reduce the mechanical failure rate when pfn was used to treat intertrochanteric fractures. pfn, inserted by means of a minimally invasive procedure, allows surgeons to minimize soft tissue dissection, thereby reducing surgical trauma and blood loss. the results of this meta - analysis also demonstrates that operative time, intraoperative blood loss, and length of incision in the pfn group are significantly less than in the dhs group. therefore, because of its minimal invasiveness, we recommend pfn as a better choice than dhs in the treatment of elderly patients with intertrochanteric fracture. firstly, the number of studies included and the sample size of patients were quite limited. in addition, the 6 studies were of relatively poor quality (level b), which might weaken the strength of the findings. secondly, we did not undertake a subgroup analysis of different fracture types because not all the studies included described the fracture types. furthermore, not all the studies included had long enough follow - up periods, which also reduces the power of our research. in summary, the current available data indicate that pfn may be a better choice than dhs in the treatment of intertrochanteric fractures. | backgroundthe aim of this meta - analysis was to compare the outcomes of proximal femoral nail (pfn) and dynamic hip screw (dhs) in treatment of intertrochanteric fractures.material/methodsrelevant randomized or quasi - randomized controlled studies comparing the effects of pfn and dhs were searched for following the requirements of the cochrane library handbook. six eligible studies involving 669 fractures were included. their methodological quality was assessed and data were extracted independently for meta-analysis.resultsthe results showed that the pfn group had significantly less operative time (wmd : 21.15, 95% ci : 34.91 7.39, p=0.003), intraoperative blood loss (wmd : 139.81, 95% ci : 210.39 69.22, p=0.0001), and length of incision (wmd : 6.97, 95% ci : 9.19 4.74, p<0.00001) than the dhs group. no significant differences were found between the 2 groups regarding postoperative infection rate, lag screw cut - out rate, or reoperation rate.conclusionsthe current evidence indicates that pfn may be a better choice than dhs in the treatment of intertrochanteric fractures. |
maternal immunological tolerance is essential for successfully establishing and maintaining pregnancy [1, 2 ]. in early pregnancy decidua, type 1 inflammatory t - cells significantly decrease, whereas both type 2 cells and cd56 cd16 cytokine - secreting uterine natural killer (unk) cells significantly increase compared with the nonpregnant endometrium. thus, unk cells (70%), macrophages (15%), and t - cells (10%) are the most abundant decidual leukocyte populations in early pregnancy [47 ]. interestingly, a high cd4+cd25 t regulatory / t helper (th) 17 cells ratio is also found in decidua in early human pregnancy. women with uncomplicated early pregnancies systemically display high serum th2/th1 cytokine and cd4+cd25+foxp3 + t regulatory (treg)/th17 cells ratios. the maternal immune system has to tolerate the semiallogeneic fetus in naturally conceived (nc) and in vitro fertilization (ivf) pregnancies to allow favorable pregnancy outcome [1, 2 ]. in fact a shift toward peripheral th1/th2 augmentation and th17/treg cells imbalance has been reported in women with recurrent pregnancy losses and in pregnancy - specific diseases such as preeclampsia. as the fetus is fully allogeneic to the mother in egg donation (ed) pregnancies, the maternal immune response should be more tolerogenic in these particular pregnancies [2, 12 ]. as a matter of fact, it has been hypothesized that defective maternal immune tolerance to the allogeneic fetus would lead to the development of pregnancy - specific diseases, which are more prevalent in ed, such as pregnancy - induced hypertension [1, 2 ]. actually, ed and ivf pregnancies at term display higher levels of both cd4+cd25 regulatory t - cells and cd4+cd25 activated t - cells in maternal peripheral blood mononuclear cells compared with nc gestations. in particular, the ratio of t - activated : t regulatory cells in ed pregnancies is significantly lower than that in nc pregnancies. the percentage of t - activated cells in ed pregnancies correlates positively with the number of hla mismatches. interestingly, peripheral blood mononuclear cells in ed pregnancies do not show a higher alloreactivity to the allogeneic fetus. regarding the maternal humoral immune response, pregnant women by ed at term display higher levels of il10 and il6 and lower levels of tgf in serum. nevertheless, knowledge of the wide maternal humoral immune response against the allogeneic fetus in ed pregnancies is lacking. thus the aim of this prospective study was to assess and contrast for the first time the maternal peripheral humoral immune response throughout pregnancy among nc, ivf, and ed pregnancies. circulating maternal cytokines and chemokines of th2 cells [interleukin (il) 4, il5, il6, and il10 ], th1 cells [il2, interferon - gamma (ifn), and tumor necrosis factor - alpha (tnf) ], treg cells [il10 and transforming growth factor - beta (tgf) ], th17 cells (il17), unk cells [il8, regulated upon activation normal t - cell expressed and secreted (rantes), and stromal cell - derived factor 1 alpha (sdf1) ], proinflammatory cytokine il1-beta (il1), and decidual granulocyte - macrophage colony - stimulating factor (gm - csf) were quantified. the maternal immune response of patients who developed preeclampsia was also evaluated and compared with the response of women with uneventful pregnancies. finally, obstetric and perinatal outcomes were compared between pregnancies with a semiallogeneic fetus and those with fully allogeneic offspring. this prospective study was carried out in two university centers in valencia, spain : university & polythecnic hospital la fe and valencian infertility institute. we studied 75 consecutive women whose pregnancy was achieved by three different modes of conception : nc (n = 25), ivf (n = 25), and ed (n = 25). women were enrolled in the study at the time of their first pregnancy control in one of the aforementioned hospitals. gestational age was based on the day of embryo transfer in art pregnancies and on the last menstrual period in nc pregnancies, confirmed in all cases by a first trimester ultrasound scan. exclusion criteria were multiple pregnancy, sperm donation, maternal autoimmune disease, and known maternal risk factors for preeclampsia : chronic arterial hypertension, chronic kidney disease, prepregnancy diabetes mellitus, thrombophilia, and history of preeclampsia in a previous gestation. all women who achieved pregnancy by ivf or ed received vaginal progesterone, 400 mg / day, for the first 12 weeks of gestation. patients were followed up at least quarterly until delivery, and pregnancy - related complications such as preeclampsia were gathered. the data of gestational age at delivery, weight of the newborn, and mode of delivery were also collected. during pregnancy follow - up, 8 ml of peripheral blood was drawn from each patient between gestational weeks 1114, 2022, and 3235 in one of the two hospitals. blood samples were centrifuged (3500 rpm for 10 min) at room temperature within the first 24 h after being taken, and the collected plasma was stored in 2-ml aliquots at 80c. written consent was obtained from each woman at the time of enrollment. for cytokines detection in plasma samples, the milliplex map technology (merck millipore, germany) for luminex 200 system (luminex corporation, usa) was used. the milliplex map technology is a bead - based immunoassay capable of detecting up to 50 cytokines simultaneously in small sample volumes. the luminex 200 system is a flow cytometry - based instrument equipped with two lasers, one for identifying cytokines and the other one for quantifying the concentration of the identified cytokine. the system uses exponent 3.1 software to run and analyze samples (luminex corporation, usa). four different kits were used for the detection of 14 cytokines : human cytokine / chemokine magnetic bead panel (hcytomag-60k) for rantes, human cytokine / chemokine panel ii (hcyp2mag-62k) for sdf1+, tgf1 single plex magnetic bead kit (tgfbmag-64k-01) for tgf1, and human high sensitivity t - cell magnetic bead panel (hstcmag-28sk) for gm - csf, ifn, il10, il17a, il1, il2, il4, il5, il6, il8, and tnf. samples were previously centrifuged at 1000 g for 1 min and the supernatant was collected to discard debris and excess lipids, which could interfere with the assay. for the human cytokine / chemokine panel ii and human high sensitivity t - cell kits, a 100-fold sample dilution was required. for the tgf1 detection kit, samples had to be acidified and diluted (final dilution of 1 : 30) according to the kit instructions. briefly, 25 l of samples (neat or pretreated) was incubated with antibody - immobilized beads in 96-wells plates overnight at 4c. to perform the fluorescence labeling of the proteins bound to the beads, plates were washed and incubated with the detection antibodies and subsequently with the streptavidin - phycoerythrin reagent. standard and control samples were used in each kit to develop the standard curve from which the quantitative analysis of samples was performed. finally, plates were run in the luminex 200 system following the protocol settings of the kits using exponent 3.1 software. a sample analysis was performed with exponent 3.1 software using the standard curves obtained in the acquisition for each kit. for this analysis, the fluorescence data measured during the samples acquisition were interpolated to the standard curve, and a quantitative result in protein concentration (pg / ml) was obtained. numerical continuous data were expressed as the mean (standard deviation) and median (1st3rd quartiles). a logarithmic transformation was applied to the concentration values of the different cytokines before any calculation. an exploratory heat map was built to view the evolution of the different cytokine concentration values throughout pregnancy in each group. to analyze our results, the inflammation status was summarized by performing two - group (high and low inflammation status) fuzzy clustering on the cytokines data and using the computed gom (grade of membership) to the high inflammation group as the summary variable. to better understand how the different cytokines related to the overall gom, another heat map was built with the cytokine values, and the individuals were ordered according to their gom score. finally, a beta regression mixed model was used to assess the association among inflammatory status and age, trimester, group, and other risk factors (such as body mass index (bmi) and nulliparity). other bivariate analyses between groups were performed using chi - square test for the categorical variables and t - test for continuous data. all the statistical analyses were performed using r (version 3.1.1) and the glmmadmb (version 0.8.0) and cluster (version 1.15.2) r - packages. mean age was higher in the ed group, compared with nc and ivf pregnancies. no noticeable differences were found among groups for bmi upon the first pregnancy control, nulliparity, and number of previous pregnancies and miscarriages with the same partner. the studied women did not have medical diseases and did not report receiving any medication upon the first pregnancy control except for one woman in the nc group and one in the ivf group who occasionally took benzodiazepines for anxiety. in nc pregnant women, there was a clear trend that the values of all the quantified cytokines, except rantes, tnf, il8, tgf, and sdf1, rose in the second trimester, and these high values remained in the third trimester. ivf and ed pregnant women displayed a similar cytokine pattern throughout pregnancy (figure 1). this can be seen in the exploratory heat map, which depicts the evolution of the cytokines measured in each woman throughout pregnancy (figure 2). in contrast, sdf1 and il8 were the only cytokines whose values increased in the third trimester. il8 levels were higher in the three trimesters in ed and ivf pregnancies (p = 0.017 and p = 0.008, resp.) compared with nc pregnancies. in contrast, rantes levels were lower in the three trimesters in ed and ivf pregnancies (p = 0.02 and p = 0.035) compared with nc gestations. finally, sdf1 levels in the third trimester of ed pregnancies were significantly lower versus pregnancies with autologous oocytes (p = 0.004) (table 2). the results of the fuzzy clustering performed to summarize inflammatory status are depicted in figure 3. the women in the three study groups with higher il1, il2, il4, il5, il6, il8, il10, il17a, tnf, ifn, gm - csf, and sdf1 values and lower rantes and tgf values were assigned higher gom values in accordance with higher inflammatory status. the beta regression mixed model confirmed our initial findings in the exploratory heat map and showed a statistically significant association between the higher inflammatory statuses in the second and third trimesters (p 40 years). given the small sample size, incidence of preeclampsia did not statistically differ among the three study groups (table 3). interestingly, the five women with preeclampsia displayed higher plasma sdf1 levels in the third trimester of pregnancy, compared with the average of their respective groups. no significantly different pattern was found for the remaining cytokines in preeclamptic patients compared with healthy pregnant women. no differences were recorded among the groups for gestational age at delivery and birth weight. only one fetus displayed intrauterine growth restriction whose mother was in the nc group and had preeclampsia. one ed pregnancy ended with a preterm birth, and the mother had preeclampsia and hellp syndrome. cesarean sections were more common among art pregnancies, particularly in the ed group (table 3). (1) the maternal cytokine and chemokine profile is preserved in ed pregnancies compared with the gestations with a semiallogeneic fetus. (2) the small number of patients who developed preeclampsia displayed higher plasma sdf1 levels in the third trimester of pregnancy compared with the healthy pregnant women of their respective study groups. the maternal humoral immune response throughout pregnancy was similar in pregnancies with a semiallogeneic fetus (nc and ivf) compared with those with a fully allogeneic fetus (ed pregnancies). all the quantified cytokines, except rantes, tnf, il8, tgf, and sdf1, increased in the second trimester and remained high in the third trimester. rantes levels were similar throughout pregnancy but showed lower values in the three trimesters in ed and ivf pregnancies compared with nc pregnancies. rantes is the chemokine most synthesized by unk cells at the human maternal - fetal interface. unk cells play a key role in placental development as they regulate trophoblast invasion and vascular growth. rantes is also produced by the human endometrium during the implantation period [1719 ] and by extravillous trophoblast cells (evt) at 1214 weeks of gestational age. considered to be one of the main chemokines to recruit t - cells [19, 21 ], it remains to be determined whether the lower rantes concentrations during pregnancy in ed and ivf gestations, compared with nc ones, entail clinical implications. like rantes, the tnf levels did not increase in the second and third trimesters of pregnancy. macrophages, lymphocytes, and trophoblast cells are the main producers of the proinflammatory cytokine tnf, which also contributes to insulin resistance. preeclamptic patients display high circulating levels [23, 24 ] and placental expression of tnf compared with women with uneventful pregnancies. unk cells are potent secretors of il8, which is a major neutrophil chemoattractant. found in endothelial cells a role of il8 in graft rejection has also been described [26, 27 ]. it is known that pregnancies complicated with preeclampsia display higher il8 levels compared with uncomplicated gestations [23, 2830 ]. the progressive rise in il8 throughout pregnancy in all three groups may reveal its key role in cell proliferation and angiogenesis, both of which are required to successfully maintain pregnancy. sdf1 levels increased in the third trimester compared with the first and second trimesters. oddly enough, ed pregnant women presented significantly lower sdf1 levels in the third trimester than in the two other study groups. it induces trophoblast proliferation, mediates crosstalk between trophoblasts and decidual stromal cells, and recruits unk cells into the decidua through its interaction with chemokine (c - x - c motif) receptor 4 (cxcr4). paradoxically, microarray analyses have revealed that it is the chemokine least synthesized by unk cells in the first trimester of pregnancy. a mice model has shown that sdf1 causes migration of treg cells into the pregnant uterus. actually, sdf1 is considered as alloimmune biomarker, and its expression has been reported to be high in chronic human renal allograft rejection. thus the lower sdf1 levels in the third trimester of ed pregnancies, compared to gestations with autologous oocytes, may contribute to maintaining these pregnancies with a fully allogeneic fetus. further studies are needed to clarify the role of sdf1 during gestation, particularly in ed pregnancies. finally, tgf levels lowered in the third trimester of pregnancy compared with previous trimesters. tgf is produced largely by unk cells and plays a key role in angiogenesis and immunoregulation. the higher tgf levels during the first and second trimesters may reflect the key role that unk and treg cells play in both the establishment and initial maintenance of pregnancy and the promotion of angiogenic and anti - inflammatory effects during this gestational period. one unexpected finding in the three study groups was the high levels of most of the studied pro- and anti - inflammatory cytokines in the second half of pregnancy. the maternal immune response needs to be more intense at onset of pregnancy for proper fetal immune recognition and initial tolerance of pregnancy. however, this initial maternal immune response may take place locally in the basal decidua, which may not be associated with a systemic immune response in maternal blood. even if this assumption was correct, it poses the question of why maternal plasma cytokines increase in the second half of pregnancy in uneventful gestations and which role this may play if there is any. it has been suggested that pregnancies with a completely allogeneic fetus require an enhanced maternal immune tolerance in order to achieve a successful pregnancy [2, 12 ]. actually, the percentage of foxp3 + regulatory t - cells within the cd4+cd25 t - cells in peripheral blood of term pregnant women is higher in ed pregnancies compared with nc pregnancies. the similar maternal cytokine and chemokine profile throughout pregnancies with allogeneic and semiallogeneic fetus further supports that regulatory t - cells (foxp3 +, ctla-4 +, and hla - dr+) are crucial in maintaining human pregnancy. regarding pregnancy - related disorders, the incidence of first trimester vaginal bleeding was significantly higher in ed pregnancies compared with nc and ivf gestations. this is consistent with knowledge about the higher incidence of bleeding complications in the first trimester as a result of the more frequent placental pathology in ed pregnancies. compared with healthy pregnant women, it is known that preeclamptic women present similar plasma rantes levels but higher circulating levels of il6, il8, tnf, il2/il4, ifn/il4, and th17/treg cells. in our series, the five women with preeclampsia had similar rantes levels but raised levels of alloimmune biomarker sdf1 in the third trimester of pregnancy. given our small sample size, a higher incidence of preeclampsia was not found in ed pregnancies. nevertheless, it is widely accepted that ed pregnancies are associated with a higher incidence of pregnancy - induced hypertension. thus further studies are required to elucidate if an abnormal maternal immune response against the allogeneic fetus in ed pregnancies contributes to the elevated incidence of preeclampsia in ed. in spite of the small simple size, this supports previous knowledge that incidence of perinatal complications in ed pregnancies is comparable to conventional ivf pregnancies. the strength of the present study is the fact that, to the best of our knowledge, this is the first study to compare the maternal plasma cytokine profile among nc, ivf, and ed pregnancies. the limited sample size of the three study groups can be considered as study 's main weakness. moreover, although the maternal peripheral immune response throughout pregnancy provides prospective information about the tolerogenic response in both pregnancies with a semiallogeneic fetus and with an allogeneic fetus, further studies of the placenta are required to unravel the local maternal - fetal immune response particularly in ed pregnancies. the maternal plasmatic cytokine profile of naturally conceived pregnancies was greatly conserved in ivf and ed pregnancies. despite the limited sample size, further studies are required to confirm these findings and to assess the role of sdf1 in pregnancy and in pregnancy - related disorders such as preeclampsia. | this prospective longitudinal study aimed at comparing maternal immune response among naturally conceived (nc ; n = 25), in vitro fertilization (ivf ; n = 25), and egg donation (ed ; n = 25) pregnancies. the main outcome measures were, firstly, to follow up plasma levels of interleukin (il) 1beta, il2, il4, il5, il6, il8, il10, il17, interferon gamma, tumor necrosis factor - alpha (tnf), transforming growth factor - beta (tgf), regulated upon activation normal t - cell expressed and secreted (rantes), stromal cell - derived factor 1 alpha (sdf1), and decidual granulocyte - macrophage colony - stimulating factor (gm - csf) during the three trimesters of pregnancy during the three trimesters of pregnancy ; secondly, to evaluate if the cytokine and chemokine pattern of ed pregnant women differs from that of those with autologous oocytes and, thirdly, to assess if women with preeclampsia show different cytokine and chemokine profile throughout pregnancy versus women with uneventful pregnancies. pregnant women in the three study groups displayed similar cytokine and chemokine pattern throughout pregnancy. the levels of all quantified cytokines and chemokines, except rantes, tnf, il8, tgf, and sdf1, rose in the second trimester compared with the first, and these higher values remained in the third trimester. ed pregnancies showed lower sdf1 levels in the third trimester compared with nc and ivf pregnancies. patients who developed preeclampsia displayed higher sdf1 plasma levels in the third trimester. |
chronic subdural hematoma (csdh) is a common disease in modern neurosurgery practice especially for the elderly patients. in contrast, non - traumatic subdural hematoma (sdh) caused by intracranial arteriovenous fistula (avf) is extremely rare, and there are only a few cases described in the literature.8)13) furthermore, dural avfs are usually accompanied by intracerebral hemorrhage (ich) or subarachnoid hemorrhage (sah), but they hardly ever present with the acute or chronic sdh.3) the author reports herein an interesting case of recurrent csdh primarily associated with dural avf which required repeat craniostomy and finally cured with embolization of middle meningeal artery. this 67-year - old male man has had a progressively worsening pain on the left cranium over 2 weeks that intractable to some analgesics. there was no recent head trauma or other medical disease in his history. on admission, brain computed tomography (ct) scans revealed an isodense left - sided csdh with marked cerebral shifting (fig. there was no evidence of source of this hemorrhage with temporal predilection on the ct angiogram. on magnetic resonance (mr) image subsequently obtained, the abnormal intensity within the subarachnoid space and the brain parenchyma was not visible. the patency without steno - occlusion in both transverse and sigmoid sinuses was clearly delineated on t2-weighted sequences (fig. this patient has received a trephination and sdh drainage, after that he was sent home with resolution of headache. approximately 2 weeks later, however, he developed an excruciating pain in the temporal and parietal regions with recurrence of subdural collection. he was immediately returned for subdural irrigation and decompression through the prior burr - holes. the patient 's clinical course was not eventful, but he complained of a mild headache again. follow - up ct scanned just prior to discharge was strikingly for the newly - formed thin hematoma at the operative site (fig. another evacuation of this subacute subdural clot was not deemed to be necessary. at this time, on the 7 day after the second surgery, angiography was performed to rule out an occult vascular lesion. a flow - guided type microcatheter (prowler 10, cordis neurovascular, miami lakes, fl, usa) was positioned in the main trunk of the mma for selective angiography. the frontal and parietal branch of the mma was appeared normally, and the abnormal membrane staining on the affected side was not detected. a left external carotid angiogram disclosed a dural avf between the petrosquamosal branch of the mma and the transverse - sigmoid sinus without retrograde cortical venous draining. it was suggested that the bleeding from the draining venous system of the dural avf led to refractory csdh. the microcatheter was introduced into the petrosquamosal branch of the mma, thereafter polyvinyl alcohol particles ranging 150 to 250 m were distally injected (fig. after trans - arterial obliteration of the feeder and fistula, the av shunt disappeared. the recurrent hematoma of this patient did not increase, and his complaints of headache gradually subsided. the brain ct at one year following the embolization therapy revealed complete regression of the subdural hematomas (fig. intracranial dural avfs are pathologic communications between dural arteries and dural venous sinuses, meningeal veins, or cortical veins. these uncommon conditions are usually located in the transverse, sigmoid, cavernous, and superior sagittal sinus.2) the characteristic imaging feature is thrombosed sinus, dilated vessel, and hemorrhage within the adjacent cerebrum.17) in the present case, angiograms indicated the existence of dural veins that were connected to the anomalous artery arising from the left mma at the lower posterior convexity. therefore, the author made a firm diagnosis of a dural avf in the area of the transverse - sigmoid sinus, and it was assumed that the oozing from the route of drainage with high flow inputs was responsible for the progression and relapse of csdh.16) another explanation for refractory csdh is that repeated bleeding into the subdural space caused by the rupture of neo - vessels in an external membrane of hematoma.7)10)13) however, angiography of this patient did not visualize cotton wool - like staining along the branches of the mma, which is microcapillary network of the hematoma membrane. dural avfs have various clinical manifestations from aggressive neurological defects to no or minor symptoms and signs depending mainly on the pattern of abnormal drainage of the veins.1) classification systems which are based on its mode of venous flow are used in cases of davf to estimate hemorrhage risks and to decide management strategies.4) intracranial hemorrhage occurs in less than 20% of all these pathologies, and the bleeding is usually subarachnoid, more infrequently intra - parenchymal, and rarely in the subdural space.19) for that reason, the presence of dural avf was not initially considered in the author 's case with only csdh without ich and sah. in the pertinent literature, there have been only 4 documented cases with idiopathic dural avf complicated by acute non - traumatic sdh.5)6)7)8) dural avfs near the superior sagittal sinus were confirmed by cerebral angiogram in all of them. the sinus was well delineated as the drainer in those cases and in this report ; however, angiography did not show a retrograde drainage into the cortical veins in the vicinity of the fistulas. the initial complaint was acute headache in the five patients including this representative case, but this is a unique illustration of the case with dural avf that complicated pure csdh.3) non - traumatic csdh is an uncommon pathology in neurosurgery, and its diagnosis and treatment is a not straightforward process. neurosurgeons must be aware of the differential diagnosis for spontaneous csdhs because those develop secondarily to a few kinds of vascular lesion, such as aneurysms, arterial rents, arteriovenous malformations, intracranial avfs, and veno - sinus thrombosis.8)9)15)18)21) according to literature review, a few cases with sdh or effusion, an exclusive revelation of cerebral veno - sinus thrombosis, have been reported thus far.10) it has been proposed that the formation of sdh in this rare occurrence was associated with increased venous and capillary pressure.11) both ct and mr scans with arterio - venography are necessary to detect an occult vascular lesion and to prevent future problems in patients with a non - traumatic csdhs. in addition, conventional angiography is the most valuable and decisive means for such patients and both internal and external carotid injections are essential for diagnosis and therapy. this briefing implies that dural avf might be the cause of rare cases with intractable csdh that were cured by the craniotomy and extensive membranectomy. craniostomy and intravascular approach provides the least invasive and definitive treatment for the rare condition of csdh and coexisting dural avf. trans - venous embolization, which is one of the most effective therapies for dural avfs, is now considered as an alternative to the craniotomy and excision in many cases.14) trans - arterial embolization may be beneficial to another patients had a dural avf, although it often lead to incomplete occlusion of the venous pouch.20) in the present case, however, the avf can be secured by trans - arterial approach through the left mma, because it was not difficult to select and penetrate the dural feeder in a single session. during the trans - arterial procedure, liquid embolic materials should penetrate into the draining veins to obliterate the fistula permanently.12) for this illustrative case, after the super - selective advancing a microcatheter to the draining vein, the interventionist administered polyvinyl alcohol particle into the fistula and veins, and the dural avf was completely eliminated. the author reported on a non - traumatic case who initially presented with csdh caused by bleeding from a dural avf involving the transverse - sigmoid sinus. brain investigation including dynamic mr image and ct venography and catheter angiography is strongly recommended for the cases with acute sdh and intractable csdh of obscure origin. | the author has encountered a 67-year - old man with dural arteriovenous fistula (avf) presenting as a non - traumatic chronic subdural hematoma (csdh). this previously healthy patient was hospitalized due to progressive headache with subacute onset. he underwent burr - hole surgery twice for evacuating the left csdh that was thickest at the posterior temporal area. the operative procedure and finding was not extraordinary, but subdural hematoma slowly progressed for days following the revision surgery. after investigation by super - selective external carotid angiography, a dural avf found near the transverse - sigmoid sinus was diagnosed. dural avf was completely occluded with trans - arterial injecting polyvinyl alchol particles into the petrosquamosal branch of the middle meningeal artery. the patient showed a good neurological outcome with no additional intervention. brain surgeons have to consider the possibility of dural avf and perform cerebral angiogram if necessary when they manage the cases that have a spontaneously occurred and repeatedly recurring csdh. |
chronic renal failure (crf) is defined as a progressive decline in renal function associated with a reduced glomerular filtration rate. the most common causes are diabetes mellitus, glomerulonephritis, polycystic kidney disease, pyelonephritis and chronic hypertension. worldwide, the number of cases of cfg is increasing ; oral healthcare providers are increasingly likely to provide care for patients with this disease.13 the clinical signs and symptoms of renal failure are collectively termed uremia. crf affects most body systems, and its clinical features are dependent upon the stage of renal failure and the systems involved. the treatment of crf includes dietary changes, correction of systemic complications and dialysis or renal transplant.1 crf can give rise to a wide spectrum of oral manifestations, which affect the hard or soft tissues of the mouth.4 delayed eruption of permanent teeth in children with crf,5,6 enamel hypoplasia of the primary and permanent teeth with or without brown discoloration7 and narrowing or calcification of the pulp chamber of teeth of adults with crf have been reported.8,9 changing rates of dental caries have also been observed in groups of patients with crf.3,10 the findings of a previous study showed that the ph of the saliva of uremic patients receiving hemodialysis is alkaline because of the high concentration of ammonia as a result of ureal hydrolysis.12,13 mahmoud investigated the influence of uremia on the shear bond strength of composite resin to enamel and dentin substrates along with an assessment of the micromorphological etching pattern of the enamel and dentin surfaces using atomic force microscopy. the authors found that uremia adversely affects bonding of resin composites to enamel and dentin and confers an altered micromorphological etching pattern. the appearance of teeth is of great importance to patients that seek esthetic treatments related to dental discoloration. among treatments, tooth bleaching has attracted the interest of patients and dentists because it represents a non - invasive option and is relatively simple to carry out.15 in particular, at - home bleaching techniques received worldwide acceptance after first being described in 1989 by haywood and heymann.16 ten percent carbamide peroxide is the bleaching agent most used for this technique16 because it is considered safe and effective.17 as whitening of vital teeth generally involves direct and frequent contact of the bleaching agent with the outer enamel surface and sometimes with dentine for an extensive period of time, in vitro studies have evaluated the effects of carbamide peroxide on dental hard tissues. changes have been observed in surface texture,1822 mineral content,2326 chemical composition,20,27,28 and loss by tooth brushing abrasion.29 additionally, some in situ studies, which represent an intermediate stage between in vitro studies and clinical trials,30 have investigated the effects of bleaching treatment on microhardness of dental enamel27,3133 and dentine.32,34 surface morphology,27,35 roughness35 and calcium content in enamel27 have also been investigated. however, the effect of whitening agents on enamel and dentin of uremic patients has still not been evaluated. considering the preceding information together with the desire of uremic patients to bleach his / her teeth, the present study aimed to investigate the effect of 16% carbamide peroxide bleaching gel on surface micromorphology and roughness of the enamel and root dentin of uremic patients receiving hemodialysis using atomic force microscopy (afm). twenty caries - free molar teeth that had been extracted for periodontal reasons were collected from healthy individuals (n=10 molars) and uremic patients (n=10 molars). the teeth were obtained according to a protocol that was approved by our institution committee for ethics of research. both healthy individuals and uremic patients were seeking dental care advise at the outpatient dental clinic, faculty of dentistry, mansoura university. however, uremic patients were under regular hemodialysis treatment by biocompatible membranes that were dialyzed with a volumetric machine using bicarbonate dialysate three times weekly for four hours each (12 h / week). none of the uremic patients had decompensated organs other than the kidney, and all patients had a serum creatinine level above 7 mg / dl and a creatinine clearance rate of less than 10 ml / min. all the collected teeth were subjected to thorough scaling (varios 550, nsk nakanishi, japan) and ultrasonic cleaning (pro - sonic 300 mth, sultan chemists inc, englewood, nj) to get rid of both hard and soft deposits and stored in 0.1% thymol (ph=7.0). the roots were separated from their crowns at the cemento - enamel junction using a low speed water - cooled diamond saw (isomet 1000, buehler, lake bluff, il, usa). enamel slabs (3 mm x 2 mm x 2 mm) were obtained from the middle third of the buccal surface, while dentin slabs were cut from the cervical third of the root surface with the same dimensions. dental slabs were fixed with stick wax in acrylic resin cylinders, and the upper surface of the specimens was then flattened and serially polished up to # 2500-grit roughness with silicon carbide abrasive papers. specimens were placed in an ultrasonic cleaner (t1440d, odontobrs ltda., ribeiro preto, sp, brazil) with distilled water for 10 min to remove polishing debris. a stereomicroscope (nikon 88286, tokyo, japan) at 40x magnification was employed to select the samples without cracks or structural defects, which would compromise the results of the study. half of the specimens in each category (healthy enamel, uremic enamel, healthy dentin, and uremic dentin) were bleached. bleaching treatment was performed with 16% carbamide peroxide bleaching gel with neutral ph (polanight, lot # 03072, sdi limited, bayswater, victoria, 3153, australia). the application protocol was for 8 h, and then the specimens were rinsed with distilled water and stored in artificial saliva at 37c. the remaining half were stored in artificial saliva and left without bleaching for control and comparison. the artificial saliva used was the one described by arvidson and johansson36 and was prepared by chemistry department, faculty of pharmacy, mansoura university. it was consisted of 4.1 mm kh2po4, 4.0 mm na2hpo4, 24.8 mm khco3, 16.5 mm nacl, 0.25 mm mgcl2, 4.1 mm citric acid, and 2.5 mm cacl2. the ph of the saliva was adjusted to 6.7 with 10 n hcl and then sterilized by 0.2-m filtration before use.36 all specimens were analyzed using afm. each specimen was fixed to the microscope holder with a cyanoacrylate adhesive and examined using afm (thermomicroscop autoprob cp, model no : ap-0100, santa barbara, ca, usa). contact mode ; physical contact between the tooth surface and the afm tip was maintained at all times with constant force. afm images were collected at a very low scan rate of 1 hz to obtain details of the enamel and dentin structure and to avoid damaging the tip. an area of 25.0 m was captured for the afm image using a scanning speed of 80 ms in air. a one - way analysis of variance (anova) and bonferroni post hoc multiple comparisons test were conducted to determine if there were differences among the bleached and non - bleached groups. twenty caries - free molar teeth that had been extracted for periodontal reasons were collected from healthy individuals (n=10 molars) and uremic patients (n=10 molars). the teeth were obtained according to a protocol that was approved by our institution committee for ethics of research. both healthy individuals and uremic patients were seeking dental care advise at the outpatient dental clinic, faculty of dentistry, mansoura university. however, uremic patients were under regular hemodialysis treatment by biocompatible membranes that were dialyzed with a volumetric machine using bicarbonate dialysate three times weekly for four hours each (12 h / week). none of the uremic patients had decompensated organs other than the kidney, and all patients had a serum creatinine level above 7 mg / dl and a creatinine clearance rate of less than 10 ml / min. all the collected teeth were subjected to thorough scaling (varios 550, nsk nakanishi, japan) and ultrasonic cleaning (pro - sonic 300 mth, sultan chemists inc, englewood, nj) to get rid of both hard and soft deposits and stored in 0.1% thymol (ph=7.0). the roots were separated from their crowns at the cemento - enamel junction using a low speed water - cooled diamond saw (isomet 1000, buehler, lake bluff, il, usa). enamel slabs (3 mm x 2 mm x 2 mm) were obtained from the middle third of the buccal surface, while dentin slabs were cut from the cervical third of the root surface with the same dimensions. dental slabs were fixed with stick wax in acrylic resin cylinders, and the upper surface of the specimens was then flattened and serially polished up to # 2500-grit roughness with silicon carbide abrasive papers. specimens were placed in an ultrasonic cleaner (t1440d, odontobrs ltda., ribeiro preto, sp, brazil) with distilled water for 10 min to remove polishing debris. a stereomicroscope (nikon 88286, tokyo, japan) at 40x magnification was employed to select the samples without cracks or structural defects, which would compromise the results of the study. half of the specimens in each category (healthy enamel, uremic enamel, healthy dentin, and uremic dentin) were bleached. bleaching treatment was performed with 16% carbamide peroxide bleaching gel with neutral ph (polanight, lot # 03072, sdi limited, bayswater, victoria, 3153, australia). the application protocol was for 8 h, and then the specimens were rinsed with distilled water and stored in artificial saliva at 37c. the remaining half were stored in artificial saliva and left without bleaching for control and comparison. the artificial saliva used was the one described by arvidson and johansson36 and was prepared by chemistry department, faculty of pharmacy, mansoura university. it was consisted of 4.1 mm kh2po4, 4.0 mm na2hpo4, 24.8 mm khco3, 16.5 mm nacl, 0.25 mm mgcl2, 4.1 mm citric acid, and 2.5 mm cacl2. the ph of the saliva was adjusted to 6.7 with 10 n hcl and then sterilized by 0.2-m filtration before use.36 each specimen was fixed to the microscope holder with a cyanoacrylate adhesive and examined using afm (thermomicroscop autoprob cp, model no : ap-0100, santa barbara, ca, usa). contact mode ; physical contact between the tooth surface and the afm tip was maintained at all times with constant force. afm images were collected at a very low scan rate of 1 hz to obtain details of the enamel and dentin structure and to avoid damaging the tip. an area of 25.0 m was captured for the afm image using a scanning speed of 80 ms in air. a one - way analysis of variance (anova) and bonferroni post hoc multiple comparisons test were conducted to determine if there were differences among the bleached and non - bleached groups. afm images of non - bleached enamel specimens obtained from healthy individuals (he) showed the surface of the enamel rods with tightly packed projections of smaller sized grains in close proximity to each other without any specific alignment. in contrast, afm images of bleached specimens (bhe) revealed enamel grains of larger size with deep micro porosities in between (figure 1b). in the non - bleached enamel specimens obtained from uremic patients ' (ue), the micromorphological observation of the afm images revealed less distinct sized enamel grains with mild surface pitting and several shallow, longitudinal grooves in between the enamel rods (figure 1c). meanwhile, the bleached uremic enamel specimens (bue) showed small enamel projections in close proximity to each other with no specific rod alignment (figure 1d). the micromorphological observation of the dentin specimens obtained from non - bleached healthy individuals (hd) revealed regularly arranged dentinal tubules with the peritubular dentin protruding slightly above the intertubular dentine (figure 2a). however, the bleached specimens (bhd) showed erosion of intertubular dentin, and the peritubular dentine subsequently became more protruded (figure 2b). moreover, afm images of dentin specimens obtained from uremic patients (ud) showed an increase in the amount of intertubular dentin on the expanse of the dentinal tubules lumen as most of the tubules lumens were occluded (figure 2c). however, the bleached specimens (bud) showed no observable changes compared to non - bleached uremic ones (figure 2d) means and standard deviations of the average roughness (ra) for non - bleached and bleached enamel and dentin specimens obtained from healthy individuals and uremic patients extrapolated from afm digital images records are presented in (table 1, figure 3). the anova for surface roughness of enamel and dentin obtained from bleached and non - bleached healthy individuals and uremic patients (table 2) reveals a significant effect in the interaction of the substrate and bleaching agent (p=0.000). bonferroni post hoc multiple comparisons test showed no significant difference between the mean ra of healthy enamel and bleached uremic enamel specimens (p=0.285). in contrast, significant differences were found between the mean ra of the other tested specimens (p<.05). in vitro models can be used to gain important information on the safety of products in terms of their effects on the hard tissues and to provide mechanistic understanding of the bleaching process. this laboratory study was undertaken to evaluate the impact of 16% carbamide peroxide bleaching gel on surface roughness of structurally different tooth substrates obtained from healthy individuals and uremic patients. overall, when carbamide peroxide comes in contact with the outer enamel surface, it breaks down into water and oxygen, which diffuses through the organic content of enamel. this causes oxidation of organic pigments that are mainly located within dentine, which results in a reduction or elimination of the discoloration. when comparing hydrogen peroxide to carbamide peroxide, the approximate equivalent of 3.3% hydrogen peroxide equals 10% carbamide peroxide.29 in accordance with habelitz,37 a cyclic model including periods of bleaching and remineralization with artificial saliva was used in this study to simulate physiological conditions during home bleaching procedures. it was assumed that a bleaching period of 8 h would reflect the clinical situation. the amount of carbamide peroxide that was chosen would be sufficient to fully cover the surface of the enamel and dentin. the artificial saliva used had a ph of 6.7 and contained electrolytes to mimic human saliva. compared to conventional microscopes (such as scanning electron microscopes, transmission electron microscopes and electron probe microanalyzers) and other newer microscopes (such as confocal laser scanning microscopes and x - ray scanning analytical microscopes), afm offers a powerful tool for directly observing demineralization because it offers advantages of high resolution and the potential to operate in the air or in solution. afm can also provide quantitative data regarding surface morphology.31, 32 in the present study, afm evaluation of the alterations in surface topography after 16% carbamide peroxide cyclic bleach application for 14 days on the enamel specimens obtained from healthy individuals revealed increased microporosities after bleaching. this is in accordance with efeoglu who concluded that in vitro application of 10% carbamide peroxide on enamel for two weeks causes demineralization of the enamel, extending to a depth of 50 m below the enamel surface. afm images of bleached, healthy dentin showed that both intertubular and peritubular dentin was affected by carbamide peroxide, with peritubular dentin appearing more affected than intertubular dentin. this in similar to a study by chnga who indicated that peritubular dentin is hyper - mineralized and lacks collagen as an organic component of its matrix. the authors also demonstrated that collagen is the major organic component of intertubular dentin, making up approximately 92% of the organic matrix. meanwhile, the afm images of non - bleached uremic enamel showed flat topographic rod surfaces with shallow longitudinal grooves in between, while the enamel of these teeth when bleached showed small enamel grains that have a tendency for close packing with shallow porosities in between, which indicates a resistance to demineralization. this can be explained on the basis that uremia makes enamel more resistant to demineralization and agrees with the findings of a previous study that showed that the ph of the saliva of uremic patients receiving hemodialysis was alkaline because of the high concentration of ammonia as a result of ureal hydrolysis.12 the loss of metabolic control of calcium and phosphorus parallels the loss of renal function. therefore, renal failure - mediated phosphate retention plus dietary phosphorus could lead to an increased phosphorus level in saliva up to 1011 mg / dl in contrast to a normal level of 56 mg / dl. consequently, one could speculate that uremia and its effect on the salivary phosphorus level and composition renders the enamel more acid resistant and therefore a cause for the decreased roughness after enamel bleaching compared to healthy enamel.14 uremic non - bleached dentin specimens showed occlusion of dentinal tubules ' lumens, and the effect of the bleaching agent was not observable on these teeth. these results are in agreement with previous studies,35, 39 which showed that characteristic changes analogous to those seen in bone were detected in dentin of erupted teeth in patients with crf. a morphometric analysis of teeth extracted from healthy individuals and patients with crf revealed that the predentin in patients suffering from crf is significantly thicker than normal.40 van meerbeek suggested that demineralization is more difficult in both the peritubular and intertubular regions of sclerotic dentin. jandt42 reported that surface roughness values obtained with afm from different biomaterials can only be compared if the area of the obtained value is of similar size. in this study, afm measurements were taken for a 20 m x 20 m area of the surface ; the mean ra of either bleached or non - bleached specimens varied significantly between the samples obtained from healthy individuals and uremic patients (p<.001). the mean values for the non - bleached uremic specimens showed the smallest ra for enamel (86 nm) and dentin (207 nm), whereas the mean ra values for the healthy bleached specimens were the highest for enamel (126 nm) and dentin (274 nm). additionally, the roughness average of the bleached and non - bleached healthy specimens exceeded that of the uremic bleached and non - bleached ones. to our knowledge, there is no available data in the literature to confirm or contradict the results of the present study, and further investigations are still needed to further clarify these observations. further clinical studies regarding the degree of bleaching of uremic teeth will also be necessary. on the basis of these results and despite the limitations of this study, it seems reasonable to conclude that the negative effects of using bleaching gel on uremic tooth substrates are less dramatic and non - destructive compared to healthy substrates because uremia confers different micromorphological surface changes. | objectives : to investigate the effect of 16% carbamide peroxide bleaching gel on surface micromorphology and roughness of enamel and root dentin of uremic patients receiving hemodialysis using atomic force microscopy (afm).methods : a total of 20 sound molars were collected from healthy individuals (n=10) and uremic patients (n=10). the roots were separated from their crowns at the cemento - enamel junction. dental slabs (3 mm x 2 mm x 2 mm) were obtained from the buccal surface for enamel slabs and the cervical third of the root surface for dentin slabs. dental slabs were then flattened and serially polished up to # 2500-grit roughness using silicon carbide abrasive papers. half of the slabs obtained from healthy individuals and uremic patients were stored in artificial saliva and left without bleaching for control and comparison. the remaining half was subjected to a bleaching treatment using 16% carbamide peroxide gel (polanight, sdi limited) 8 h / day for 14 days and stored in artificial saliva until afm analysis was performed. statistical analysis of the roughness average (ra) results was performed using one - way anova and bonferroni post hoc multiple comparisons test.results:the micromorphological observation of bleached, healthy enamel showed exaggerated prism irregularities more than non - bleached specimens, and this observation was less pronounced in bleached uremic enamel specimens with the lowest ra. bleached healthy dentin specimens showed protruded peritubular dentin and eroded intertubular dentin with the highest ra compared to bleached uremic dentin.conclusions:the negative effects of the bleaching gel on uremic tooth substrates are less dramatic and non - destructive compared to healthy substrates because uremia confers different micromorphological surface changes. |
inflammation of the pericardium due to infection or non - infectious etiology is known as pericarditis. the most common forms are idiopathic and viral which are usually self - limiting and benign conditions. predisposing factors include renal disease, previous cardiac and thoracic surgery, endoscopic oesophageal variecal sclerotherapy, laproscopic nissins fundoplication, fiberoptic bronchoscopy and percutaneous coronary angioplasty the portal of entry is usually direct invasion of infection from adjacent pneumonia or empyema and to a lesser extent may be due to hematogenous seeding from a distant infection. we report a fatal case of acute purulent pericarditis due to methicillin - resistant staphylococcus aureus (mrsa) with molecular characterization of its resistance mechanisms. a 78-year - old male who was a known case of squamous cell carcinoma of buccal mucosa, which was excised with cervical lymph node dissection two years ago along with systemic hypertension and renal failure (urea 179 mg / dl, creatinine 5.28 mg / dl) was hospitalized with complaints of fever since 10 days and dyspnoea on exertion class iii of two days duration. a chest x - ray [figures 1 and 2 ] showed massive pericardial effusion and an electrocardiogram (ecg) [figure 3 ] revealed low voltage waves, st elevation, atrial fibrillation and a fast ventricular rate. the white cell count was 21 k/l with 88% neutrophils and liver enzymes were also elevated (sgot 103 iu / l, sgpt 80 emergency pericardiocentesis was done and 800ml of fluid was drained and a pigtail catheter was introduced through a subxiphoid incision and placed under fluoroscopic guidance in the pericardial cavity. pericardial fluid analysis showed ada 15.2 u / l, glucose 97.8 g / dl, protein 5.84 g / dl. chest x - ray on admission showing a massive pericardial effusion with a pig - tail catheter in situ for drainage chest x - ray after pericardiocentesis showing a pig - tail catheter left in situ for continuous drainage electrocardiogram on admission showing low voltage waves in leads ii, iii and avf ; st elevation in leads i, ii, avl and chest leads v1 v6 ; atrial fibrillation and a fast ventricular rate of 134 beats / min blood and pericardial fluid cultures grew gram positive cocci which were identified as mrsa with the vitek 2 (biomerieux, inc., both the mrsa isolates (from blood and pericardial fluid) were resistant to multiple classes of antibiotics namely oxacillin, penicillin, trimethoprim - sulfamethoxazole, gentamicin and ciprofloxacin while susceptible to vancomycin, clindamycin, tertracyline, linezolid, quinupristin / dalfopristin, nitrofurantoin, and rifampicin as determined by vitek 2 system. vancomycin (1 g / ml) and daptomycin (0.94 g / ml) susceptibility was confirmed by etest (biomerieux, inc., the isolate was intermediately sensitive to erythromycin (1 g / ml) and a d - test for inducible clindamycin resistance was found to be negative. the mrsa isolate from blood and pericardial fluid were identical and identification was confirmed by amplifying the 16s rdna gene of the genus staphylococcus and sau gene specific for s. aureus. a multiplex polymerase chain reaction (pcr) was done to simultaneously detect genes responsible for resistance to four classes of antibiotics and the isolate was positive for aac a - aph d, erm (c) and meca encoding for resistance to aminoglycoside, erythromycin and oxacillin respectively. the organism was susceptible to tetracycline and, therefore, tetk and tetm genes were not amplified. the patient who was empirically put on piperacillin / tazobactum was shifted to vancomycin when cultures identified the isolate as mrsa on the third day. subsequently he developed septic shock and metabolic acidosis and expired on the fourth day of admission due to heart failure. purulent pericarditis historically a disease of children and young adults has been a rare entity in the modern antibiotic era. since 1945, the median age at the time of diagnosis has increased from 21 to 49 years. the predisposing factors in the post antibiotic era were found to be an underlying non - infectious condition like thoracic surgery or chronic renal disease. pericardial diseases are more common in patients with renal disease and frequency has declined from 20%, which was 35 years ago, to 5% presently. in most of these cases pericardial fluid did not show any evidence of infection, making purulent pericarditis a rare entity. due to the absence of typical pericarditis features diagnosis of purulent pericarditis these patients typically present with an acute illness characterized by fever, chills, and tachycardia. pericardial rub and chest pain are frequently not present and ecg may be normal in 35% of cases. primary site of infection is rarely pericardium and four pathways have been described for its spread to the pericardium namely direct extension of an intrathoracic process, penetrating injury to the chest wall, local extension and hematogenous spread. purulent pericarditis following percutaneous procedures is being increasingly reported and therefore these nosocomial infections are more likely to be caused by multi - drug resistant (mdr) pathogens. though the introduction of antibiotics has drastically reduced the incidence of purulent pericarditis in the last few decades, it is slowly reemerging due to the increased prevalence of mdr pathogens. s. aureus is the most common cause of purulent pericarditis, and therefore reports of mrsa purulent pericarditis are on the rise. even though there are potent antibiotics to treat mrsa a delay in diagnosis often leads to high mortality. our case highlights one such case of fatal purulent pericarditis caused by and mdr mrsa where early diagnosis and appropriate empirical antibiotic therapy could have resulted in a favorable outcome. we suggest that acute purulent pericarditis with mdr mrsa should be considered in patients with renal disease. | though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. we report a fatal case of purulent pericarditis and sepsis due to methicillin - resistant staphylococcus aureus in a 78-year - old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism. |
inadequate bone quantity in the posterior maxilla secondary to pneumatization of the maxillary sinus and/or postextraction alveolar ridge resorption can compromise dental implant placement, therefore requiring site grafting prior to implant placement using techniques such as maxillary sinus floor elevation. the ideal material for bone grafting should be biocompatible, induce no host rejection, present no risk of disease transmission, promote support for bone regeneration, and have mechanical stability from the outset, which should be maintained throughout the healing period. the maxillary sinus floor elevation technique described by tatum and published by boyne and james in 1980 described autologous bone as the filling material for the sinus cavity, which is still regarded as the gold standard in bone reconstruction. if, on the one hand, autologous grafts present osteoconductive, osteoinductive, and osteogenic potential, on the other, they present some risks. this has translated into a constant search for the development of biomaterials to substitute autologous bone grafts, for instance, xenografts [5, 6 ], homologous grafts [7, 8 ], and synthetic grafts [9, 10 ]. bone substitute biomaterials lack cellularity, which has encouraged much research into the field of tissue engineering in order to combine autologous osteogenic cells with osteoconductive materials. consequently, the bone marrow is currently the most explored source of autologous cells, since it contains a number of bone regenerating cells, such as undifferentiated mesenchymal cells that can differentiate into osteoblasts [12, 13 ]. they also present an angiogenic potential due to the production and release of vascular endothelium growth factor, which is highly desirable for graft integration. osteoconductive graft enrichment in reconstructive surgery for maxillary sinus floor elevation can be performed using cells from a bone marrow aspirate concentrate obtained by centrifugation [1619 ]. this method is regarded as simple and safe because it is performed using autologous material immediately before surgery. therefore, the aim of this study was to histomorphometrically evaluate the use of a bone xenograft enriched with autologous bone marrow aspirate concentrate (bmac) for maxillary sinus floor lifting. this study was conducted in the outpatient clinic of the department of implant dentistry of the so leopoldo mandic dental school (campinas, sp, brazil), upon approval by the research ethics committee (694.065/2014) and free and informed consent forms for all the patients. the inclusion criteria involved completely edentulous patients needing implants in the posterior maxillary region with no more than 4 mm of remaining alveolar ridge, with need for maxillary sinus floor augmentation. the patients also committed to returning for follow - up appointments and to maintaining adequate oral hygiene. patients were excluded if they had a history of neoplastic disease treated with radiotherapy or chemotherapy, if they were pregnant or breastfeeding, if they were receiving treatment or were affected by an illness that could have an effect on bone homeostasis, allergy to any of the materials used, and sinus pathologies, or if they were smokers. cone - beam computed tomography scans of the posterior maxillary region were obtained to measure the height of the posterior maxillary bone and the size of the maxillary sinus. the ct scans were also used to evaluate possible sinus pathologies (figure 1). eight patients with a mean age of 55.4 9.2 years were included in this study. the patients were randomly divided using online - based software available at http://www.randomization.com/ into two groups according to the material used, control group (cg) (n = 8) with bio - oss only and test group (tg) (n = 8) with bio - oss combined with bone marrow concentrate obtained by the bmac method, and each patient had the same graft material placed in each sinus. following the principles of the guided bone regeneration technique, collagen membranes were placed over the bone window for all sinus floor augmentation procedures in both groups. all patients were dentally rehabilitated using osseointegrated implants and fixed prostheses at the end of the study. according to the instructions by the manufacturer, bone marrow was harvested and processed directly in the operating room using the bmac system (bone marrow procedure pack, harvest technologies, plymouth, ma, usa). briefly, in an outpatient setting and using local anesthesia (2% xylocaine without a vasoconstrictor), 30 ml of bone marrow was collected from all the patients by aspiration through a puncture 2 cm laterocaudally from the superior posterior iliac crest, using a bone marrow needle (included in the pack), with 30 ml syringes previously heparinized (1 ml of 5.000 u / ml heparin) (figure 2). the syringe containing 30 ml of bone marrow was connected to a filter bag, to which 8 ml of acd - a anticoagulant was added. after appropriate homogenization, new syringe and needle were connected and the filtered 30 ml was removed. the bone marrow aspirate was then transferred into specific process disposables, which were placed in a smartprep2 centrifuge. after centrifugation for 14 minutes, two phases were obtained within the container, that is, the supernatant plasma and the precipitated bone marrow cells concentrate (figure 3). the plasma was removed using specific syringes provided in the kit and the cell concentrate was resuspended and approximately 4 ml was aspirated. a lateral window was prepared using number 3 pm spherical diamond bur (medical burs ind. e com. the schneiderian membrane was carefully released (figure 4) using specific curettes (neodent, curitiba, pr, brazil) and the maxillary sinuses were grafted with xenogeneic bone from bovine hydroxyapatite, (1 - 2 mm bio - oss, geistlich biomaterials, wolhusen, switzerland) (figure 5), either alone or combined with the bone marrow concentrate (figure 6). a collagen membrane of porcine origin (bio - gide, geistlich biomaterials, wolhusen, switzerland) was used to cover the graft and the osteotomy of the lateral maxillary sinus wall, thus impeding migration of soft tissue to the graft region. after 6 months, 16 bone biopsies (one per sinus) were taken using a trephine bur (2.0 mm in diameter and 18 mm in length) (figure 7). immediately after that, the implants (blackfix, as technology, so jos dos campos, brazil) were placed (figure 8). the bone biopsies were fixed in 4% formaldehyde solution (merck, darmstadt, germany). the suture was made with ethilon - nylon 4 - 0 (ethicon, ma, usa). after the surgery, each patient was prescribed amoxicillin 500 mg (12/12 hours for 5 days). all patients were rehabilitated with metal - ceramic prosthesis over the implants six months after its installation. the histological analysis was performed at the histopathology laboratory of the so leopoldo mandic dental school (campinas, sp, brazil). the biopsies underwent decalcification in 10% edta for 36 hours and then processed following a conventional histological method for hard tissue. the entire area of the trephine biopsy above the native bone of the sinus was defined as region of interest and histomorphometrically evaluated. the fragments were masson 's trichrome - stained and four different areas of each fragment were evaluated in the histology slides (upper left, lower left, upper right, and lower right), which were then averaged out., diagnostic instruments, sterling heights, mi, usa) coupled with an optical microscope (1.25x magnification). the digital images were merged to create a single image for each histological cut, using adobe photoshop elements 2.0 software (adobe systems, san jose, ca, usa) (figures 9(a) and 9(b)). the examiners traced new bone formation on all the images using imagej pro plus 4.5 for windows software (national institute of health, nih, usa). the following parameters were considered for histomorphometry : (1) nonvital mineralized tissue (nvmt), (2) vital mineralized tissue (vmt), and (3) nonmineralized tissue (nmt). all the results were noted in square micrometers and, subsequently, stated as a percentage of the total area. for analysis of the nonvital mineralized tissue (nvmt), vital mineralized tissue (vmt), and nonmineralized tissue (nmt) parameters, the nonparametric mann - whitney test was applied with correction using the sidak - bonferroni test for the statistical analysis. at least two implants were placed in each previously grafted sinus and all of them were osseointegrated. cg and the tg showed percentages of vital mineralized tissue (vmt) area of 27.30 5.55% and 55.15 20.91%, respectively. the same groups showed percentages of nonvital mineralized tissue (nvmt) area (represented by remaining bio - oss particles) of 22.79 9.60% and 6.32 12.03%, respectively. finally, the percentages of nonmineralized tissue (nmt) area were 49.90 7.64% and 38.53 13.08%, respectively (table 1). surgery to augment the maxillary sinus is a well - documented method to generate adequate amount of bone for implant installation in the posterior maxilla [2125 ], for which various types of bone grafts have been tested. the autologous bone graft technique is considered the gold standard because of its osteoinductive, osteoconductive, and osteogenic characteristics. nevertheless, it presents some drawbacks, especially regarding operative morbidity, namely, the need for two or more surgical sites in cases of greater amount of donor tissue, including extraoral sources. this raises the operative risk and surgical costs and generates postoperative discomfort, causing fewer patients to opt for this approach. consequently, a search for bone biomaterials that could replace the autologous bone has taken place. nonetheless, these are not always graced with the advantages of osteogenesis and osteoinduction inherent of the autologous grafts. biomaterials that feature the physical, chemical, and mechanical characteristics of autologous bone have become increasingly desired, given the need for further use of the grafted area for the installation of dental implants. the literature reports on a xenogeneic bovine bone substitute, bio - oss, as a biomaterial with very similar characteristics to those of human bone, including osteoconduction [2629 ]. lyophilized xenogeneic bone tissue, or other bone substitute graft materials, lacks factors that promote osteogenesis and osteoinduction. in turn, this increases healing time compared to autologous bone, reaching a waiting period for implant placement ranging from six to eight months. this is greater than the time required for autologous grafts, which feature live cells and growth factors, therefore fulfilling their osteogenic and osteoinductive potentials. such properties reflect positively on the time required for bone healing, which may vary from four to six months. based on the aforementioned properties, methods to enhance bone substitutes combined with bone marrow cells have been investigated. studies have described techniques for harvesting and applying fresh bone marrow [3133 ] and isolating and expanding mesenchymal stem cells from the bone marrow [3335 ] as well as concentrating the bone marrow cells [18, 33, 36, 37 ] in combination with a mineralized carrier. despite these various methods, however, there is no consensus on the best alternative for bone remodeling in humans. regarding the use of cell culture, mesenchymal stem cells must be carefully considered, because they usually require a waiting period of several weeks between harvesting, culture, and transplantation, thus risking contamination. therefore, in this study, preference was given to test a clinically plausible cell concentration method from a bone marrow aspirate concentrated by centrifugation within a fully closed system. the main reason for this choice was the versatility of the technique and the unlikelihood of contamination due to the fact that the system is closed., to standardize the bone marrow transplantation for bone regeneration, a simple, safe, clean and cost - effective system is needed. in the present study, the waiting period of six months between grafting and reopening for implant placement was adopted, as it stands within the waiting period for autologous (46 months) and xenogeneic grafting (68 months). however, on the grounds that bone neoformation levels (vital mineralized tissue) in the test group were significantly higher (p = 0.002) than in the control group, 55.15 20.91% and 27.30 5.55%, respectively, one can speculate the possibility of early reopening when using the bmac method. (2010) achieved 19.9% of new bone after lifting maxillary sinuses with bio - oss associated with the bmac method. the discrepancy between the results from both studies could probably be justified on the time delay between grafting and reopening surgery. in the study by sauerbier., a healing period of approximately 4.1 months was chosen, but in some cases, reopening occurred after just 3 months. the lack of time standardization for reopening combined with a precocious second intervention may have resulted in lower levels of bone tissue as stated by sauerbier. when compared to the present study, which standardized the reopening procedures at 6 months. rickert. compared the combination of bio - oss / bmac method with bio - oss (70%) associated with autologous bone (30%) and detected no significant difference between the groups, further suggesting that the bmac method improved the reconstructive standard. nevertheless, the authors also opted for an early reopening time of approximately 3 months after grafting, which also hindered further comparisons between their data and those of the present study. regarding the levels of residual particles of bio - oss (nvmt), a significantly lower percentage (p = 0.006) was observed in the test group compared to the control, 6.32 12.03% and 22.79 9.60%, respectively. this can be hypothesized as an acceleration of the healing process in the test group, which corroborates the vmt results, since a higher rate of bone formation should translate into a higher biomaterial resorption. regarding the levels of nmt, despite the lack of significant difference between the groups (p = 0.09), a decreasing trend in the amount of nonmineralized tissue in the test group was observed, which was, on average, 10% lower than in the control group. there have been very few reports on the use of the biomaterials and techniques investigated in the present preliminary study. this study indicates that the clinical use of bone marrow aspirate concentrate obtained by the bmac method associated with a xenograft for maxillary sinus elevation resulted in more adequate bone repair than the xenograft alone. | purpose. to investigate the regenerative results obtained with the association of bone marrow aspirate concentrate using the bone marrow aspirate concentrate (bmac) method to a xenogeneic bone graft (bio - oss) in sinus floor elevation. materials and methods. using a randomized controlled study design in eight consecutive patients (age of 55.4 9.2 years), 16 sinus floor lift procedures were performed with bio - oss alone (control group, cg, n = 8) or combined with bone marrow aspirate concentrate obtained via the bmac method (test group, tg, n = 8). six months after the grafting procedures, bone biopsies were harvested during implant placement and were analyzed by histomorphometry. results. histomorphometric analysis revealed a significantly higher amount (p 0.05) of nonmineralized tissue (38.53 13.08% and 49.90 7.64%, resp.). conclusion. the use of bone marrow concentrate obtained by bmac method increased bone formation in sinus lift procedures. |
perhaps because of ingrained cultural beliefs about the infallibility of computation, people show a level of trust in computed outputs that is completely at odds with the reality that nearly zero provably error - free computer programs have ever been written 2, 3. it has been estimated that the industry average rate of programming errors is about 15 50 errors per 1000 lines of delivered code. that estimate describes the work of professional software engineers not of the graduate students who write most scientific data analysis programs, usually without the benefit of training in software engineering and testing 5, 6. the recent increase in attention to such training is a welcome and essential development 7 11. nonetheless, even the most careful software engineering practices in industry rarely achieve an error rate better than 1 per 1000 lines. since software programs commonly have many thousands of lines of code (table 1), it follows that many defects remain in delivered code even after all testing and debugging is complete. defects occur not only in the top - level program being run but also in compilers, system libraries, and even firmware and hardware and errors in such underlying components are extremely difficult to detect. of course, not every error in a program will affect the outcome of a specific analysis. for a simple single - purpose program, it is entirely possible that every line executes on every run. in general, however, the code path taken for a given run of a program executes only a subset of the lines in it, because there may be command - line options that enable or disable certain features, blocks of code that execute conditionally depending on the input data, etc. furthermore, even if an erroneous line executes, it may not in fact manifest the error (i.e., it may give the correct output for some inputs but not others). finally : many errors may cause a program to simply crash or to report an obviously implausible result, but we are really only concerned with errors that propagate downstream and are reported. in combination, then, we can estimate the number of errors that actually affect the result of a single run of a program, as follows : number of errors per program execution = total lines of code (loc) proportion executed probability of error per line probability that the error meaningfully affects the result probability that an erroneous result appears plausible to the scientist. for these purposes, using a formula to compute a value in excel counts as a line of code, and a spreadsheet as a whole counts as a programso many scientists who may not consider themselves coders may still suffer from bugs. all of these values may vary widely depending on the field and the source of the software. for a typical analysis in bioinformatics, i ll speculate at some plausible values : 100,000 total loc (neglecting trusted components such as the linux kernel).20% executed10 errors per 1000 lines10% chance that a given error meaningfully changes the outcome10% chance that a consequent erroneous result is plausible 100,000 total loc (neglecting trusted components such as the linux kernel). 10 errors per 1000 lines 10% chance that a given error meaningfully changes the outcome 10% chance that a consequent erroneous result is plausible so, we expect that two errors changed the output of this program run, so the probability of a wrong output is effectively 100%. let s imagine a more optimistic scenario, in which we write a simple, short program, and we go to great lengths to test and debug it. in such a case, any output that is produced is in fact more likely to be plausible, because bugs producing implausible outputs are more likely to have been eliminated in testing. 1 error per 1000 lines 10% chance that a given error meaningfully changes the outcome 50% chance that a consequent erroneous result is plausible here the probability of a wrong output is 5%. the factors going into the above estimates are rank speculation, and the conclusion varies widely depending on the guessed values. measuring such values rigorously in different contexts would be valuable but also tremendously difficult. regardless, it is sobering that some plausible values indicate total wrongness all the time, and that even conservative values suggest that an appreciable proportion of results are erroneous due to software defects above and beyond those that are erroneous for more widely appreciated reasons. all of these values may vary widely depending on the field and the source of the software. for a typical analysis in bioinformatics, i ll speculate at some plausible values : 100,000 total loc (neglecting trusted components such as the linux kernel).20% executed10 errors per 1000 lines10% chance that a given error meaningfully changes the outcome10% chance that a consequent erroneous result is plausible 100,000 total loc (neglecting trusted components such as the linux kernel). 10 errors per 1000 lines 10% chance that a given error meaningfully changes the outcome 10% chance that a consequent erroneous result is plausible so, we expect that two errors changed the output of this program run, so the probability of a wrong output is effectively 100%. let s imagine a more optimistic scenario, in which we write a simple, short program, and we go to great lengths to test and debug it. in such a case, any output that is produced is in fact more likely to be plausible, because bugs producing implausible outputs are more likely to have been eliminated in testing. 1 error per 1000 lines 10% chance that a given error meaningfully changes the outcome 50% chance that a consequent erroneous result is plausible here the probability of a wrong output is 5%. the factors going into the above estimates are rank speculation, and the conclusion varies widely depending on the guessed values. regardless, it is sobering that some plausible values indicate total wrongness all the time, and that even conservative values suggest that an appreciable proportion of results are erroneous due to software defects above and beyond those that are erroneous for more widely appreciated reasons. a response to concerns about software quality that i have heard frequently particularly from wet - lab biologists is that errors may occur but have little impact on the outcome. this may be because only a few data points are affected, or because values are altered by a small amount (so the error is in the noise). the above estimates account for this by including terms for meaningful changes to the result and the outcome is plausible. nonetheless, in the context of physical experiments, it is tempting to believe that small errors tend to reduce precision but have less effect on accuracy i.e. if the concentration of some reagent is a bit off then the results will also be just a bit off, but not completely unrelated to the correct result. we can not apply our physical intuitions, because software is profoundly brittle : small bugs commonly have unbounded error propagation. a sign error, a missing semicolon, an off - by - one error in matching up two columns of data, etc it is rare that a software bug would alter a small proportion of the data by a small amount. more likely, it systematically alters every data point, or occurs in some downstream aggregate step with effectively global consequences. in general, software errors produce outcomes that are inaccurate, not merely imprecise. bugs that produce program crashes or completely implausible results are more likely to be discovered during development, before a program becomes delivered code (the state of code on which the above errors - per - line estimates are based). consequently, published scientific code often has the property that nearly every possible output is plausible. when the code is a black box, situations such as these may easily produce outputs that are simply accepted at face value : an indexing off - by - one error associates the wrong pairs of x s and y s.a correlation is found between two variables where in fact none exists, or vice versa.a sequence aligner reports the best match to a sequence in a genome, but actually provides a lower - scoring match.a protein structure produced from x - ray crystallography is wrong, but it still looks like a protein.a classifier reports that only 60% of the data points are classifiable, when in fact 90% of the points should have been classified (and worse, there is a bias in which points were classified, so those 60% are not representative).all measured values are multiplied by a constant factor, but remain within a reasonable range. an indexing off - by - one error associates the wrong pairs of x s and y s. a correlation is found between two variables where in fact none exists, or vice versa. best match to a sequence in a genome, but actually provides a lower - scoring match. a protein structure produced from x - ray crystallography is wrong, but it still looks like a protein. a classifier reports that only 60% of the data points are classifiable, when in fact 90% of the points should have been classified (and worse, there is a bias in which points were classified, so those 60% are not representative). all measured values are multiplied by a constant factor, but remain within a reasonable range. a software error may produce a spurious result that appears significant, or may mask a significant result. if the error occurs early in an analysis pipeline, then it may be considered a form of measurement error (i.e., if it systematically or randomly alters the values of individual measurements), and so may be taken into account by common statistical methods. however : typically the computed portion of a study comes after data collection, so its contribution to wrongness may easily be independent of sample size, replication of earlier steps, and other techniques for improving significance. for instance, a software error may occur near the end of the pipeline, e.g. in the computation of a significance value or of other statistics, or in the preparation of summary tables and plots. the diversity of the types and magnitudes of errors that may occur 16 19 makes it difficult to make a general statement about the effects of such errors on apparent significance. however it seems clear that, a substantial proportion of the time (based on the above scenarios, anywhere from 5% to 100%), a result is simply wrong rendering moot any claims about its significance. all hope is not lost ; we must simply take the opportunity to use technology to bring about a new era of collaborative, reproducible science 20 22. open availability of all data and source code used to produce scientific results is an incontestable foundation 23 27. beyond that, we must redouble our commitment to replicating and reproducing results, and in particular we must insist that a result can be trusted only when it has been observed on multiple occasions using completely different software packages and methods. this in turn requires a flexible and open system for describing and sharing computational workflows. projects such as galaxy, kepler, and taverna have made inroads towards this goal, but much more work is needed to provide widespread access to comprehensive provenance of computational results. perhaps ironically, a shared workflow system must itself qualify as a trusted componentlike the linux kernel in order to provide a neutral platform for comparisons, and so must be held to the very highest standards of software quality. crucially, any shared workflow system must be widely used to be effective, and gaining adoption is more a sociological and economic problem than a technical one. | errors in scientific results due to software bugs are not limited to a few high - profile cases that lead to retractions and are widely reported. here i estimate that in fact most scientific results are probably wrong if data have passed through a computer, and that these errors may remain largely undetected. the opportunities for both subtle and profound errors in software and data management are boundless, yet they remain surprisingly underappreciated. |
pain as a frequent occurrence after dental procedures concerns patients and has an adverse impact on patient satisfaction. third molar post extraction pain (pep) is one of the most common models successfully used in recent years for assessing the analgesic efficacy of pain - killing drugs. pain is a subjective experience influenced by many factors such as patient age, cultural and educational level, past experiences, pain threshold and tolerance which makes its objective assessment difficult. despite these limitations, a visual analog scale (vas) is universally considered to be the most appropriate instrument for pain measurement and is the most widely used means for scoring postoperative pain and specifically that caused by the surgical extraction of the lower third molar.[46 ] the literature has it that many factors are related to pep (such as patient age, surgical parameters, number of sutures, degree of impaction, etc.). some have strong supporting evidence confirming their relationship while some are still mired in controversy. most of the literature focuses little attention on the patient and surgical factors that influence third molar pep. however, one of the most important factors regulating oral health is saliva. for diagnostic and prognostic purposes, routine dental practice should therefore include the measurement of certain important salivary factors such as ph and flow rate, which tend to have a highly significant linear correlation as well. there is also some evidence indicating that low extracellular ph (i.e., tissue acidosis) is frequently seen with inflamed tissue, which results in the activation of nociceptors and pain fibers. it has been indicated that environmental stimuli, such as ph, may have clinical significance in the development of dental pain. we intended to carry out a study in patients subjected to lower third molar extraction, with the aim of analyzing the influence of salivary ph on pain. the samples comprised of 13 women and 18 men, aged 18 to 24 years, with a mean age of 21.02 2.05 years.they did not have a medical condition or use any sort of medication and were nonsmokers. written consent was obtained from all the subjects and the study was approved by the ethics committee of our university. the subjects were asked to avoid eating and drinking from 10 p.m. on the night before surgery, excluding water, coffee and tea without sugar or cream. the subjects were given instructions regarding the saliva collection which was performed in a normal sitting position. the ph measuring process was carried out without delay with a combination electrode connected to a phm 62 ph meter (radiometer a / s, copenhagen, denmark). in order to eliminate any other influencing factors affecting pep, factors such as age, surgical parameters, degree of impaction and number of sutures were attempted to be as paralleled and standardized as possible. each patient 's third molar showed the same degree of impaction (fully covered by bone) and needed a similar surgical procedure on occasion (the surgical procedure was standardized by the same surgeon under local anesthesia). alveolar nerve block and no sedation), the local anesthetics administered was lidocaine 2% (1 : 80,000 norepinephrine). ostectomy was performed using a round bur (no.8 carbide) and a low - speed straight handpiece under constant irrigation of cool saline solution. surgical sites were sutured (4 - 0 silk) and analgesics wereprescribed at six - hour intervals (ibuprofen tab. the scale was quantified from 0 to 10 in which 0 and 10 denoted no pain and maximum pain, respectively. the data was presented as mean standard deviation and for quantitative variables and frequency (percentage) for sex. the kolmogorov - smirnov test was used to check the normal distribution of variables. the relationship between pain score, age and ph pain scores were also compared between males and females according to the t - test. a multiple linear regression was used to detect variables that could affect the pain score. in this analysis, age (year), sex (male=1, females=0) and ph (unit) were entered in the model via the stepwise method with 0.05 inclusion and 0.1 for exclusion criteria. chicago i 11) and the level of significance was set at p 0.05. alveolar nerve block and no sedation), the local anesthetics administered was lidocaine 2% (1 : 80,000 norepinephrine). ostectomy was performed using a round bur (no.8 carbide) and a low - speed straight handpiece under constant irrigation of cool saline solution. surgical sites were sutured (4 - 0 silk) and analgesics wereprescribed at six - hour intervals (ibuprofen tab. the scale was quantified from 0 to 10 in which 0 and 10 denoted no pain and maximum pain, respectively. the data was presented as mean standard deviation and for quantitative variables and frequency (percentage) for sex. the kolmogorov - smirnov test was used to check the normal distribution of variables. the relationship between pain score, age and ph pain scores were also compared between males and females according to the t - test. a multiple linear regression was used to detect variables that could affect the pain score. in this analysis, age (year), sex (male=1, females=0) and ph (unit) were entered in the model via the stepwise method with 0.05 inclusion and 0.1 for exclusion criteria. chicago i 11) and the level of significance was set at p 0.05. from 31 patients, 18 were male (58.1%) and the mean age (sd) was 21.0 2.0 years. regarding the intensity of pain, the mean pain score was 5.72 1.02. pain (p = 0.544), age (p=0.486) and ph (p = 0.273) had normal distributions. based on the univariate analysis, no association was observed between saliva ph and age (p = 0.79). age also did not have any effect on postoperative pain (p = 0.48). the saliva ph had a significant reverse correlation (r = - 0.654, p < 0.001) with postoperative pain. the multivariate analysis suggested that the factors that influenced pain were patient 's sex (p = 0.041) and the saliva ph (p < 0.001). adjusted r - square for the model was 0.645 [figure 1 ]. increase in 1 unit of ph suggested a decrease in pain of 1.09 units and males reported 0.466 units lower than females. postoperative pain is a consequence following surgical extraction of fully impacted lower third molar teeth. the many factors that contribute to these situations are complex, but they originate in an inflammatory process initiated by surgical trauma. we have found that lower salivary ph may lead to higher intensity of pain after extraction of the lower third molars. regarding the relationship between patient 's age and pep, many controversial reports have been published thus far ; some advocating a relationship and some disapproving such.[1519 ] saliva plays a crucial role in maintaining the oral ecosystem[2022 ] and ph is shown to have a reverse correlation, with the growth of lactobacillus and yeast in the oral cavity. the relationship between chronic craniofacial pain, such as migraine and the salivary flow rate has also been investigated. goodis, studied tissue ph and temperature regulation of pulpal nociceptors in laboratory rats. their study indicated that environmental stimuli regulated the activity of capsaicin - sensitive neurons innervating the dental pulp and these factors may be significant clinically in the development of dental pain. foodstuff, stress, surgery and drugs may influence salivary ph and a randomized clinical trial by duane suggests that the use of high - dose xylitol chewing gum has beneficial effects on plaque ph and streptococcus mutans in children at high risk for caries. many antibiotics are secreted in the saliva and may affect salivary ph (which may in turn affect pep). however, among these many contributing factors, very little, if any attention has been directed toward the relationship between salivary ph and the intensity of pep. we failed to find a similar study in the literature search and this was a limitation of our study. in our study, we found salivary ph to affect pep intensity with a reverse correlation. the more acidic it was the greater was the pain. due to the fact that no previous study has evaluated such findings so far, further studies are needed to assess the importance of ph value and its clinical significance on the level of pep, in light of other confounding factors. | aimthe literature focuses little attention on factors that influence third molar post extraction pain (pep). one factor that may play a role in pep is saliva. we undertook a study in patients subjected to third molar extraction with the aim of assessing the influence of salivary ph on pep.materials and methods : thirty - one healthy patients with one impacted inferior lower third molar with mean age of 21.02 2.05 years, underwent surgery for similar impactions. the process of ph measuring was carried out without delay after saliva collection, with a combination electrode connected to a phm 62 ph meter. pain assessment was done at 4, 8, 12, 18 and 24 hours on the first day. the scale ranged from 0 to 10 in which 0 and 10 denoted no pain and maximum pain, respectively.results:the multivariate analysis suggests that the factors that influence pain are patients sex (b = - 0.466) and the saliva ph (b = - 1.093). according to the findings of our study, pep intensity is assumed to have a reverse correlation with salivary ph and is also assumed to be greater in females.conclusion:due to the fact that no previous study has indicated such findings so far, further studies are needed to assess the importance of preoperative ph value and its clinical significance on the level of pep. |
since the seminal work of ostwald in the late 19th century, crystal nucleation and growth have remained of constant, if not even increasing, interest. today, applications of crystal engineering range from quantum dots and nanomaterials to biomimetic composites and pharmaceutical formulation. in parallel to pushing the limits of creating new materials by brute - force methods such as high - throughput screening robots, we are experiencing considerable improvements in experimental investigation techniques and simulation methods. the combination of both types of characterization approaches is currently paving the way to an increasingly rational design of crystalline compounds. the key to this highly desirable, but still rather far - off goal is an in - depth understanding of the processes involved at a molecular scale. the need for molecular - scale understanding has increased sharply recently, as the observation of multi - stage nucleation processes and the identification of prenucleation clusters challenges our current theoretical mainframe for rationalizing the underlying thermodynamics. for such phenomena, the traditional concept of classical nucleation theory faces serious shortcomings[4, 5]and ultimately motivated the term non - classical nucleation. to exploit new perspectives of solid - state syntheses by designing precursor solutions and/or triggering secondary nucleation events, extensions to classical nucleation theory are required. the aim of the present concept article is to provide a survey on the thermodynamics of nucleation, be it multi - step or straight (e.g. classical), also considering the recently identified prenucleation clusters. moreover, we briefly discuss kinetics, experimental and numerical simulation methods that have proven to be valuable tools for rationalizing the molecular - scale processes involved in solute association, cluster / nuclei formation and the growth of crystals. a simple and intuitive rationalization of crystal formation was provided by gibbs, who contrasted two key driving forces, one of which promotes and one that disfavors the formation of a crystal.[6, 7 ] from a purely thermodynamic point of view, crystallization should occur when super - saturation, under - cooling or pressure causes the crystalline phase to be more stable than the corresponding solution or melt, respectively. however, immediate phase transfer is typically observed only upon rather drastic favoring of the crystalline state, as for example by vaporization of the solvent. unlike crystal formation by a manifold of spontaneous nucleation events (spinodal decomposition of the pristine phase), the more common scenario is that of crystal formation being hindered by a barrier in free energy. classical nucleation theory (cnt) relates this barrier to the need of a forming crystal nucleus to establish an interface with the surrounding melt, vapor or solution. surface tension and unfavorable interactions at the interface give rise to an increase in free energy, which scales with the surface area a of the forming nucleus. on the other hand, favorable interactions within the inner core of the forming nucleus lead to a prospective gain in free energy, which scales with the volume v of the nucleus. the central merit of cnt is to describe the competition of both aspects by two simple terms in order to provide an energy profile as a function of nucleus size. in what follows, g(n) is considered as the free energy difference in comparing the dispersed solution comprising n solutes with an analogous system in which all n solutes form an aggregate and are embedded by equal amounts of solvent molecules and modeled at identical temperature and pressure as considered for the dispersed solution [eq. (1) ] : for spherical nuclei the two energy terms may be written as a function of the radius, but a shape - independent formulation of cnt may be obtained by considering the surface and the bulk energy terms as a function of the number of solutes n in the nucleus. assuming the inner structure of the nucleus as identical to that of the final crystal, the gain in free energy upon crystallization reads n with being the change in free energy per solute. a further assumption often used relies on the nuclei to maintain a constant shape (such as spheres, cubes, prisms, polyhedra, etc.) during the whole formation process. in this case the surface area is given by fn with f being a constant that depends on the habit of the nucleus. for example, a spherical shape would lead to equation (2) : where refers to the particle density of the forming crystal. this allows describing nucleation free energy as a function of the number of precipitated solutes [eq. (3) ] : from which the nucleation barrier and the critical nucleus size is deduced as equation (4) : it is important to point out that both the surface and the volume terms are related to constant prefactors csurface and, respectively. on this basis, cnt provides a simple rationale of the free energy profile as a function of size (figure 1 a). results should, however, be regarded from a more qualitative viewpoint as there are a number of examples that show the shortcomings of assuming constant shape and inner structure of the nuclei as discussed in the following. a) classical nucleation pathway : small nuclei are dominated by interface / surface domains accounting for an increase in free energy, whilst sufficiently large nuclei are stabilized from favorable packing in the bulk, leading to a net gain in free energy. b) two - step nucleation mechanism with low secondary nucleation barrier : the initially formed phase a (red curve) is that of lowest nucleation barrier, that is, nuclei of comparably low surface tension / interface energy are observed. upon later stages of nuclei growth the core domain in the aggregate becomes dominant and transformation to phase b (blue curve) is driven by more favorable packing in the bulk. c) competition of crystal structures with large barriers to polymorphic transitions : same as (b) but for weaker thermodynamic preference of the ab transition and/or larger barrier to the secondary nucleation event. the size - induced transformation may be subject to large hysteresis effects or even inhibit structural reorganization at all. d) prenucleation clusters : non - constant bulk and surface / interface energy terms may lead to (local) minima in the energy profile and give rise to meta - stable (blue curve) or even stable (red curve) prenucleation clusters. molecular simulation studies have proven particularly valuable for extending our mechanistic understanding beyond classical nucleation theory. on the one hand, this applies to the surfaces of forming nuclei : to minimize interfacial free energy, diffusive and dynamically changing nucleus melt or nucleus solvent interfaces appear more favorable. however, an even more important issue is the need to consider structural transitions within the inner core of a forming crystal. first evidence for this was collected by ostwald, leading to the famous ostwald s step rule which suggests a series of structural transitions during crystal nucleation. while the original argument was based on preferential nucleation of a phase that is structurally similar to the preceding one, a more thermodynamic rationale of multi - step nucleation processes is given by following the pathway encompassing the lowest nucleation barrier.[1, 9 ] the latter criterion can be considered as a qualification of the former, if structural similarity of two phases is interpreted in terms of the ease to transform the one into the other. an important example of two - step nucleation is given by solute segregation in terms of a single disordered cluster or a partially ordered agglomerate of clusters, followed by aggregate ordering at a later stage of the precipitation process.[1013 ] an explanation of such non - classical nucleation may indeed be given by considering the competition of (at least) two phases. here, the final crystal structure implies most favorable solute packing in the bulk and is thus the predominant phase for large crystal nuclei. on the other hand, the formation of disordered clusters could give rise to roughly spherical aggregates of particularly favorable surface tension and/or interface energy. in this case, the disordered structure is thermodynamically preferred for small aggregates, whilst the crystalline structure is only stable for larger aggregates. illustrations for such two - step nucleation are given in figures 1 b, c. it is noteworthy that the secondary nucleation step requires a size - induced phase transition of the forming aggregate. depending on the solute, such liquid solid or solid solid transformations may be subject to a considerable energy barrier. as a consequence, hysteresis effects might shift the secondary nucleation step to late stages of aggregate growth or even fully inhibit transformation to the thermodynamically preferred structure. a prominent example of the latter case is given by molecular crystals, which are particularly often found to nucleate in terms of different polymorphic structures depending on the specific synthesis conditions (and thus different rankings of the corresponding nucleation barriers). by means of molecular simulation we can monitor the evolution of a forming molecular crystal nucleus as a function of size. an example is given in figure 2, which shows a series of snapshots of norleucine aggregation from a nonpolar solution. the initial oligomers are associated by hydrogen bonding, whilst the nonpolar alkyl chains point towards the aggregate surface. this micelle - type structure evolves to hydrogen - bonded bilayers upon incorporation of up to about 150 molecules. at later stages, the transition from two - dimensional to three - dimensional aggregates is observed, eventually leading to staggered bilayers akin to the final crystal structure. however, even upon aggregate growth to 1000 solutes, the evolution of the investigated d-/l - norleucine aggregates is still incomplete as the transformation of hydrogen - bonded dimer motifs to enantiopure chains still gives rise to solid solid transformations. this example hence shows that during the nucleation of d-/l - norleucine a cascade of structural transitions (micellesbilayersstaggered bilayersmolecular crystal) is experienced. each of the competing structures refer to different surface tension and bulk energy terms, leading to size - dependent thermodynamic stability, which is suggested as the driving force for the observed multi - step nucleation pathway. evolution of a forming molecular crystal of d-/l - norleucine as obtained from molecular simulation. in nonpolar (octanole) solvent, the solutes initially form hydrogen - bonded micelles and bilayers. at later stages, additional bilayers nucleate from the pristine structure and aggregates of staggered bilayers are observed. this multi - step nucleation mechanism hence encompasses a series of solid solid transformations between competing structures of size - dependent thermodynamic stability. similar to the size - dependent phase stability discussed earlier for nuclei of competing crystal polymorphs, the structures and energetics of non - crystalline clusters need to be considered as functions of size as well. this gives rise to a variety of challenges to conventional cnt and the required extensions of the theory mainframe are still under development. schematically, prenucleation clusters may occur in terms of 1) relatively favorable, yet thermodynamically unstable, intermediates to crystal nucleation (figure 1 d). long - standing examples for discontinuous size dependence in cluster energy are magic - number clusters observed during metal crystallization from the vapor.[15, 16 ] molecular dynamics simulations showed that the evolution of forming metal nuclei involves structural transitions from nuclei with crystalline bulk to compact polyhedra of particularly favorable surface tension and vice versa. on the other hand, 2) prenucleation clusters may also occur as the thermodynamically favored species with respect to the dispersed solutes. stable is then used to describe prenucleation clusters that coexist with dispersed solutes in solutions below the saturation limit. a simple example of such a solution is given by tenside molecules in water. here, the formation of micelles may be rationalized by a favorable interface energy term and unfavorable bulk energy, thus flipping the chart characteristic to conventional cnt (compare figures 1 a and d). comparing micelles with dispersed tenside molecules, favorable interface energy arises from the segregation of hydrophobic moieties. on the other hand, unfavorable bulk (free) energy results from insufficient solute solute interactions compared to the entropy change needed for solute aggregation. a similar argument might apply to the most popular type of prenucleation clusters, that is, clusters that are coordinated by surfactants a prominent example being zn4o(acetate)6 clusters observed in ethanolic solutions of zinc acetate dihydrate.[1719 ] in such systems, we are however not aware of a rigorous proof of thermodynamic stability (which would refer to case 2) and kinetic hindering could also account for preventing ripening to zno. while the (relative) stability of the cluster types discussed above is intuitive and has been well - established for many decades, the recent discovery of an unexpected type of prenucleation species considerably extended our picture of solutions prior to nucleation. using ultracentrifugation, coelfen and gebauer identified caco3 prenucleation clusters in aqueous solution. in absence of surfactants, the rationale based on micelles does not apply. on the other hand, arguments based on specific structures of preferential energy such as the magic - number clusters observed for metals also appear unreasonable as caco3 is known to (initially) nucleate as amorphous aggregates. on the basis of molecular simulations wallace and de. therein, polyionic chains account for favorable interactions in the bulk, whilst the interfacial energy between the ion - rich and the ion - poor solutions appears as practically zero.[22, 23 ] an initially prepared dispersed solution of calcium carbonate below the saturation limit would therefore undergo spinodal decomposition to form the suggested liquid - like prenucleation species. interestingly, experiments do not show separation into two entirely distinct phases, indicating that the liquid - like droplets of high ion content are limited in size. assuming vanishingly low, but clearly not negative interface tension, limitations to the droplet size can only be a consequence of a size - dependent term for the free energy of the aggregate bulk. on the one hand, this might be due to the loss in entropy arising from changing a micro - elusion - type scenario into that of a large single droplet. additionally, a possible rationale could build on the study of gale and coworkers who found that amorphous caco3 incorporates an increasing number of water molecules per caco3 formula unit with increasing aggregate size. this implies an increasing degree of immobilized water molecules, giving rise to entropic disfavoring. we suggest that a similar mechanism might account for limiting the size of the liquid - like poly - ionic chains. short ion chains are essentially linear and bind only water molecules of the first hydration shell, whilst larger droplets imply extended networks of nested poly - ionic chains that would encapsulate water and are thus subject to increasingly unfavorable entropy. unfortunately, molecular dynamics simulations could so far only hint at the first part of this concept, whereas the latter part is still speculation, inspired by the swelling of ionic polymer compounds. it is tempting to interpret crystal nucleation via prenucleation clusters as a special case of the non - classical nucleation pathways discussed earlier. in this sense, the first nucleation step would be the agglomeration of prenucleation clusters, forming (partially) organized structures which could also be interpreted as meso - crystals. the secondary nucleation step then refers to the ripening of such agglomerates into the final crystal structure. an exciting perspective of such nucleation pathways is to manipulate crystal nucleation by selection of the prenucleation species acting as building blocks. this would allow promoting specific structural motifs and ideally directing crystal nucleation into specific polymorphs or compositions. using cyro - tem sommerdijk and faivre recently provided strong evidence for this concept by capturing different stages of iron oxide / hydroxide agglomeration from solution, followed by a secondary nucleation event leading to magnetite crystals. as thermodynamic rationale, these authors suggested to use classical nucleation theory as developed for nucleation from disperse solution (figure 1 a), but to introduce an offset in terms of size and free energy to describe nucleation from precursor clusters. this offset directly corresponds to the (local) minima in the free energy profiles illustrated in figure 1 d. the key question is whether such offsets to the free energy level of the solution indeed lead to lower effective nucleation barriers (as evidently the case for the above study on magnetite). nucleation from particularly favorable solute clusters could instead imply an increase in the free energy barrier as compared to the dispersed solution. we argue that this depends on the crossing of the free energy profiles related to the prenucleation clusters with the energy curve corresponding to conventional nucleation from solution. figure 3 illustrates the three possible scenarios depending on the degree of thermodynamical stability and the size distribution of the prenucleation clusters compared to the critical nucleus estimated from classical nucleation theory. metastable prenucleation clusters may be interpreted as relatively favorable intermediates to crystal nucleation and are thus well - suited as building blocks to non - classical crystal nucleation. for clusters that are thermodynamically preferred over solutions of dispersed solutes crystal nucleation from prenucleation clusters : the black curve refers to classical nucleation of a crystal from a solution of dispersed ions and the colored curves illustrate the possible energy profiles for prenucleation clusters. the blue curve corresponds to a metastable prenucleation cluster which may be interpreted as a relatively favorable intermediate to crystal nucleation. the effective barrier to crystal formation (a) is lower than that of conventional nucleation from the ionic solution (0). for stable prenucleation clusters, two scenarios may apply : large prenucleation clusters of broad size distribution can imply low effective barriers to crystal nucleation (c) and may thus serve as precursors to crystal formation. on the other hand, small prenucleation clusters of sharp size distribution would imply an increase in effective nucleation barrier (b). in this case, crystal nucleation appears more favorable in regions of the ionic solution, initially not affecting the prenucleation clusters. the free energy diagrams shown in figure 3 illustrate two different types of such clusters. here, only the example of large prenucleation clusters of broad size distribution exhibits a low effective barrier to crystal nucleation, thus qualifying the clusters as building blocks to crystal formation. (note that the crossing of the free energy curves only reflects a rough estimate of the transition barrier and that it ignores the possibly quite large increase in energy barrier arising from cluster reorganization.) contrary to this, the illustrated curve for small prenucleation clusters of sharp size distribution indicates a considerable barrier for the clusternucleus transition (even using the lower estimates as obtained from figure 3). for the given example, this barrier is even larger than the barrier to nucleation from bulk solution. consequently, nucleation is expected to take place within the bulk ionic solution without affecting the previously formed clusters and the term prenucleation cluster is misleading. indeed, this type of cluster formed prior to nucleation would persist until later stages of crystal growth as described next. clusters that are the most stable species present in solution prior to crystal nucleation may still be outperformed thermodynamically once the nuclei reach mature stages of crystal growth. the critical point is the intersection of the free energy gain from solute uptake in post - critical crystal nuclei compared to the free energy of the same number of solutes within the previously formed clusters (figure 4, green curve). the fate of the beforehand stable clusters in solution then is to either 1) collide with a forming nucleus and merge into it ; or alternatively 2) the clusters might dissociate into solution to compensate for the depletion of dispersed ions in the solution arising from crystal precipitation. the choice of mechanisms also depends on cluster mobility compared to the diffusion of dispersed ions. interestingly, the mechanistic picture 2 is similar to the ostwald ripening of differently sized crystal nuclei. particularly for this scenario we argue that the clusters formed prior to nucleation should be regarded as buffers to ion concentrations in solution rather than precursors to crystal nucleation. on the other hand, route 1 implies that the clusters are candidate building blocks to crystal growth, but not to nucleation. free energy diagram for crystal nucleation from solution of dispersed solutes (black curve, barrier denoted as 0) initially ignoring the clusters formed prior to nucleation (green curve, barrier to direct transformation denoted as b). such clusters would coexist with (post - critical) crystal nuclei of small size (ncrit < n < ncoex). however, at more mature stages of crystal growth, the free energy gain in solute association to the growing nucleus may outperform thermodynamic preference of solute assembly in a single or multiple (here shown for 2) clusters. on the other hand (red curve), excessive stabilization of small clusters in solution may actually inhibit crystal nucleation. the dashed blue lines indicate the free energy of multiples of clusters taken as a simple linear extrapolation of the cluster of most favorable size. from a practical point of view, crystal design from precursor solutions is probably most promising for two - step processes. in the first step, particularly stable, well - defined clusters are formed prior to nucleation. by changing the solution (e.g. adding a further component etc.) the cluster stability is then reduced to provide a more reactive species that agglomerate and turn into crystal nuclei. the abovementioned zn4o(acetate)6 clusters in ethanolic solution are prominent examples for this strategy. in the initial solution, these clusters are quite stable and the nucleation of zno is typically triggered by adding hydroxide. in analogy to this, mehring and coworkers prepared dmso solutions of [bi6o4(oh)4](no3)6 cage structures as precursors to larger bismuth oxide aggregates. using molecular dynamics simulations we identified the mechanisms of precursor stabilization by coordinating nitrate ions. for intact [bi6o4(oh)4](no3)6 clusters the nitrate surfactants were shown to electrostatically inhibit the association of the clusters, thus giving rise to stable solutions. however, by lowering the ph, the clusters may be protonated and dissociation of a hno3 molecule leads to the formation of an activated species, the [bi6o4(oh)4](no3)5 cluster, which was found to bind several [bi6o4(oh)4](no3)6 clusters. the first association event and the resulting dimer after structural ripening are illustrated in figure 5. interestingly, the newly formed [bi12o8(oh)8](no3)11 cluster still refers to an activated species and was shown to bind further precursor clusters in order to grow into a crystal nucleus. we argue that the pristine [bi6o4(oh)4](no3)6 refer to clusters that were thermodynamically preferred species in the initial solution, whilst the activated species evidently correspond to metastable intermediates to crystal nucleation. the initially formed salt - bridges between nitrate and exposed bi ions were found to ripen in favor of [bi12o8(oh)8](no3)11 cluster (right). the ripened dimer shows a central bi6 octahedron with which bi4 tetrahedra are associated, giving rise to favorable (bulk - like) four - fold coordination of the o ions, whilst the oh ions are located at the aggregate boundaries only. an extreme case of promoting the stability of small clusters in solution is reflected by the free energy profile shown as the red curve in figure 4. in this case, the cluster species is thermodynamically preferred over the bulk crystal and the solution would rather form multiples of clusters than a crystal. an illustrative example for this scenario is polyacrylate additives in aqueous solution used to hinder caco3 nucleation. combing molecular dynamics simulations with an extensive structural sampling technique, parinello and coworkers demonstrated the peculiar binding of calcium and carbonate ions to the additive.[30, 31 ] despite the local accumulation of ions, crystal nucleation is still disfavored as the association with the polyacrylate additive leads to ca ca distances that mismatch with the packing in any of the known solid forms of calcium carbonate. crystal nucleation processes called non - classical elude the concept of classical nucleation theory in its conventional implementation, but classical mechanics and statistics nevertheless apply. indeed, the almost 150 year old concept of classical nucleation theory only requires small extensions to account for the manifold of nucleation and prenucleation phenomena known today. multi - step nucleation processes may be rationalized by considering multiple free energy profiles, each derived in a classical manner, that is, by contrasting unfavorable surface / interface tension to favorable bulk energy. the nucleation process will follow the route with lower barriers, which may arise from low interface tension rather than optimal bulk energy. in this case, size - induced changes in polymorph stability may be predicted from the crossing of the free energy profiles of competing crystal structures. solid transition is subject to a kinetic barrier, which implies hysteresis or even prevents the direct transformation at all. the presence of metastable clusters can lower the barrier to nucleation as compared to the dispersed solution., the term prenucleation cluster seems inappropriate for clusters that are thermodynamically more stable than the dispersed solution. crystal nucleation from such clusters might involve even larger barriers, giving rise to a hindering rather than a boosting effect. for classical crystal nucleation pathways corresponding to the energy profile illustrated in figure 1 a the kinetics may be estimated from the rate of critical nucleus formation. rate theory implies [eq. (5) ] : where t is temperature, kb the boltzmann constant and r0 denotes the kinetic prefactor, respectively. processes that determine the kinetic prefactor are solute diffusion in solution and solute desolvation in order to incorporate the solute in the forming nucleus. both of these processes are typically related to an activation energy stemming from the need to rearrange solvation shells or replacing solvent solute by solute solute contacts. formally, the kinetic prefactor may thus be written as equation (6) : when combining equations (5) and (6) it is tempting to combine the three exponential terms into a putative effective barrier g+e+e, which is, however, quite misleading as diffusion, desolvation and nucleation are separate steps. this is best seen from considering the rate of critical nucleus dissociation during a failed attempt to nucleation [eq. (7) ] : indeed, solute diffusion and de-/resolvation processes always impose a barrier that slows the kinetics, be it the forward or the backwards reaction. this motivated the interpretation of e and e as kinetic barriers, whilst g is called the thermodynamic barrier. in view of the different process steps and their corresponding activation barriers, it is useful to discriminate the two limiting cases of diffusion - controlled and nucleation - controlled crystal formation. the latter type of processes is characterized by ge+e. on the other hand, diffusion - controlled crystal formation implies no or only low barriers to desolvation and nucleation, but not necessarily eg+e. indeed, diffusion will always become rate - determining if solubility is low and nucleation occurs from very sparse solution. the two limiting scenarios crystal growth limited by mass transport to the nucleus and nucleation triggered by crossing an activation barrier give rise to rather different challenges to both experiment and molecular simulation. a broad overview of experimental techniques for characterizing nucleation processes was recently provided by bensch. and a topical survey of experimental approaches to clusters formed prior to nucleation and non - classical nucleation was provided by gebauer and coelfen. in the following, we give a brief summary of molecular simulation methods which, in combination with experimental characterization, reflect the state - of - the - art in unraveling clusters, precursors and nuclei in solution. molecular dynamics simulations reflect iterative solutions to newton s equations of motion and thus calculate molecular trajectories as small increments of time. while this time step (and hence the maximum time resolution) is typically around 1 fs, the overall simulation time is usually chosen within the ns to s regime. these time scales require millions of simulation iterations, but are still substantially lower than that of most nucleation process of experimental or industrial relevance. using specialized simulation techniques for bridging the time / length scale problem, crystal nucleation may still be assessed by molecular simulation as briefly summarized in the following (for a more detailed account see ref.). while the techniques discussed apply to all types of molecular dynamics simulations, we note that the atomic interaction forces are most accurately calculated from quantum treatment of the electrons, and specifically developed molecular mechanics models are needed to obtain similar accuracy. the latter are usually preferred, as force fields allow for assessing larger systems and longer time scales and thus provide drastically lower margins of the statistical error. for nucleation - controlled processes, the key barrier arises from ordering a domain within the melt or from desolvation and rearranging nearby solutes within a solution. to make such processes accessible to molecular simulation, the strategies developed, in one way or another, are all based on first implementing an artificial boost of solute solute interactions, and then correcting the biasing of the results. frenkel and coworkers pioneered this field by driving nucleation from the melt via a predefined order parameter that reflects nearest - neighbor distances and angles.[3436 ] to avoid bias from excessively boosting nucleation kinetics, the process is described by a series of setups each mimicking the steady state within a small interval of the order parameter. using the umbrella sampling technique, artificial potentials were implemented to restrain the order parameter within a certain range, and sketches of the energy profile (potential of mean force) were collected from boltzmann statistics.[3436 ] while umbrella sampling uses additional potentials to create attraction towards a desired state to the model system, it is also possible to induce nucleation processes by artificially creating repulsion from an unwanted configuration. the metadynamics technique reflects a systematic scan of configuration space by continuously disfavoring configurations that have been characterized before. this approach does not require prejudicing a reaction coordinate (as in umbrella sampling), but relies on a broader a set of predefined variables to which the biasing potential is applied. within this choice of descriptors, metadynamics samples configuration space free of prejudicing. more recently, transition - path - sampling molecular dynamics was employed to sample time - dependent pathways of nucleation from solution.[38, 39 ] here, an initial nucleation pathway is prepared from imposing high temperature, pressure or manipulation of the interaction potentials. increasingly realistic pathways are then collected from performing a monte carlo sampling within trajectory space confined to liquid solid transition routes. by the example of nacl aggregation in water, this approach was also tested for investigating nucleation from solution. to study diffusion - controlled crystal formation processes, gavezzoti pioneered this field by essentially ignoring long - range diffusion process and exploring the manifold of solute solute contacts from small model systems comprised of only a few solutes.[42, 43 ] this allows focusing molecular simulation to the critical issue of solute solvent bond dissociation and replacement by solute possible crystal structures are then predicted from expanding the manifold of solute solute contacts to periodic arrangements. zahn method describes solute diffusion to a forming nucleus by an inexpensive docking procedure implemented as a monte carlo step, whilst solute association and the reorganization of the aggregate is studied from explicit molecular dynamics simulations. depending on the model system, aggregate relaxation after each growth step can be modeled in different ways. 1) from direct molecular dynamics simulation of a given period of time. this leads to a kinetic monte carlo algorithm and is suited for fast precipitation processes, only. alternatively 2), wallace and de yoreo employed parallel replica simulations for an extensive sampling of configurations, thus mimicking infinite relaxation times. between these extremes, we suggest 3) a simulated - annealing - type procedure to allow aggregate relaxation to a degree that both energy profiles and aggregate structures evolve continuously as functions of nucleus size. for classical crystal nucleation pathways corresponding to the energy profile illustrated in figure 1 a the kinetics may be estimated from the rate of critical nucleus formation. rate theory implies [eq. (5) ] : where t is temperature, kb the boltzmann constant and r0 denotes the kinetic prefactor, respectively. processes that determine the kinetic prefactor are solute diffusion in solution and solute desolvation in order to incorporate the solute in the forming nucleus. both of these processes are typically related to an activation energy stemming from the need to rearrange solvation shells or replacing solvent solute by solute solute contacts. formally, the kinetic prefactor may thus be written as equation (6) : when combining equations (5) and (6) it is tempting to combine the three exponential terms into a putative effective barrier g+e+e, which is, however, quite misleading as diffusion, desolvation and nucleation are separate steps. this is best seen from considering the rate of critical nucleus dissociation during a failed attempt to nucleation [eq. (7) ] : indeed, solute diffusion and de-/resolvation processes always impose a barrier that slows the kinetics, be it the forward or the backwards reaction. this motivated the interpretation of e and e as kinetic barriers, whilst g is called the thermodynamic barrier. in view of the different process steps and their corresponding activation barriers, it is useful to discriminate the two limiting cases of diffusion - controlled and nucleation - controlled crystal formation. the latter type of processes is characterized by ge+e. on the other hand, diffusion - controlled crystal formation implies no or only low barriers to desolvation and nucleation, but not necessarily eg+e. indeed, diffusion will always become rate - determining if solubility is low and nucleation occurs from very sparse solution. the two limiting scenarios crystal growth limited by mass transport to the nucleus and nucleation triggered by crossing an activation barrier give rise to rather different challenges to both experiment and molecular simulation. a broad overview of experimental techniques for characterizing nucleation processes was recently provided by bensch. and a topical survey of experimental approaches to clusters formed prior to nucleation and non - classical nucleation was provided by gebauer and coelfen. in the following, we give a brief summary of molecular simulation methods which, in combination with experimental characterization, reflect the state - of - the - art in unraveling clusters, precursors and nuclei in solution. molecular dynamics simulations reflect iterative solutions to newton s equations of motion and thus calculate molecular trajectories as small increments of time. while this time step (and hence the maximum time resolution) is typically around 1 fs, the overall simulation time is usually chosen within the ns to s regime. these time scales require millions of simulation iterations, but are still substantially lower than that of most nucleation process of experimental or industrial relevance. using specialized simulation techniques for bridging the time / length scale problem, crystal nucleation may still be assessed by molecular simulation as briefly summarized in the following (for a more detailed account see ref.). while the techniques discussed apply to all types of molecular dynamics simulations, we note that the atomic interaction forces are most accurately calculated from quantum treatment of the electrons, and specifically developed molecular mechanics models are needed to obtain similar accuracy. the latter are usually preferred, as force fields allow for assessing larger systems and longer time scales and thus provide drastically lower margins of the statistical error. for nucleation - controlled processes, the key barrier arises from ordering a domain within the melt or from desolvation and rearranging nearby solutes within a solution. to make such processes accessible to molecular simulation, the strategies developed, in one way or another, are all based on first implementing an artificial boost of solute solute interactions, and then correcting the biasing of the results. frenkel and coworkers pioneered this field by driving nucleation from the melt via a predefined order parameter that reflects nearest - neighbor distances and angles.[3436 ] to avoid bias from excessively boosting nucleation kinetics, the process is described by a series of setups each mimicking the steady state within a small interval of the order parameter. using the umbrella sampling technique, artificial potentials were implemented to restrain the order parameter within a certain range, and sketches of the energy profile (potential of mean force) were collected from boltzmann statistics.[3436 ] while umbrella sampling uses additional potentials to create attraction towards a desired state to the model system, it is also possible to induce nucleation processes by artificially creating repulsion from an unwanted configuration. the metadynamics technique reflects a systematic scan of configuration space by continuously disfavoring configurations that have been characterized before. this approach does not require prejudicing a reaction coordinate (as in umbrella sampling), but relies on a broader a set of predefined variables to which the biasing potential is applied. within this choice of descriptors, metadynamics samples configuration space free of prejudicing. more recently, transition - path - sampling molecular dynamics was employed to sample time - dependent pathways of nucleation from solution.[38, 39 ] here, an initial nucleation pathway is prepared from imposing high temperature, pressure or manipulation of the interaction potentials. increasingly realistic pathways are then collected from performing a monte carlo sampling within trajectory space confined to liquid solid transition routes. by the example of nacl aggregation in water, this approach was also tested for investigating nucleation from solution. to study diffusion - controlled crystal formation processes, gavezzoti pioneered this field by essentially ignoring long - range diffusion process and exploring the manifold of solute solute contacts from small model systems comprised of only a few solutes.[42, 43 ] this allows focusing molecular simulation to the critical issue of solute solvent bond dissociation and replacement by solute possible crystal structures are then predicted from expanding the manifold of solute solute contacts to periodic arrangements. zahn method describes solute diffusion to a forming nucleus by an inexpensive docking procedure implemented as a monte carlo step, whilst solute association and the reorganization of the aggregate is studied from explicit molecular dynamics simulations. depending on the model system, aggregate relaxation after each growth step can be modeled in different ways. 1) from direct molecular dynamics simulation of a given period of time. this leads to a kinetic monte carlo algorithm and is suited for fast precipitation processes, only. alternatively 2), wallace and de yoreo employed parallel replica simulations for an extensive sampling of configurations, thus mimicking infinite relaxation times. between these extremes, we suggest 3) a simulated - annealing - type procedure to allow aggregate relaxation to a degree that both energy profiles and aggregate structures evolve continuously as functions of nucleus size. | recent observations of prenucleation species and multi - stage crystal nucleation processes challenge the long - established view on the thermodynamics of crystal formation. here, we review and generalize extensions to classical nucleation theory. going beyond the conventional implementation as has been used for more than a century now, nucleation inhibitors, precursor clusters and non - classical nucleation processes are rationalized as well by analogous concepts based on competing interface and bulk energy terms. this is illustrated by recent examples of species formed prior to / instead of crystal nucleation and multi - step nucleation processes. much of the discussed insights were obtained from molecular simulation using advanced sampling techniques, briefly summarized herein for both nucleation - controlled and diffusion - controlled aggregate formation. |
prostate cancer is the most common solid tumor in men and is the second leading cause of death among cancers. diagnosis is performed through fragments obtained by ultrasound - guided transrectal prostate biopsy, which is usually performed on an outpatient basis. many patients consider the procedure uncomfortable and painful ; about 65% to 90% of patients report moderate to severe pain and 20% would not repeat the procedure. some of the factors that can cause pain during biopsy are anal discomfort generated by transducer insertion and needle penetration in the rectal wall, periprostatic tissue, and prostatic capsule. the best means of analgesia for prostate biopsy has not yet been defined, and several techniques have been described, such as intrarectal lidocaine gel, anti - inflammatory drugs, periprostatic nerve block (ppnb), and sedoanalgesia [4 - 19 ]. the drug used should preferably be rapidly metabolized, have few side effects, and, if necessary, be easily reversed. anal distension during the introduction of the transducer is an important component in the mechanism of pain generated by the procedure. other pain - relieving techniques do not act on this mechanism, thus justifying the use of sedation. fentanyl citrate is an opioid drug used in treating pain ; it is characterized by rapid onset, short duration, and high efficiency. its administration is intravenous, and its action is installed within 2 - 3 minutes, lasting about 30 minutes. it is used for sedation in combination with a benzodiazepine such as midazolam in endoscopic procedures. midazolam is a sleep - inducing agent that can be administered intravenously, with rapid onset, short duration, and anterograde amnesia. the study was performed in patients from the department of urology, botucatu medical school, unesp, after approval of the ethics in research board. the inclusion criteria were as follows : abnormalities in the digital rectal examination suggesting prostate cancer, high prostate - specific antigen (psa ; > 4.0 ng / ml in men over 55 years old and > 2.5 ng / ml in men younger than 55 years old), psa density greater than 0.15, and annual psa increase greater than 0.75 ng / ml. patients with bleeding disorders, anorectal disease (hemorrhoids, anal fissure, anal stenosis), urinary tract infection in treatment or diagnosed at the time of biopsy, spinal trauma, hypersensitivity to fentanyl citrate or midazolam, or who refused to provide written informed consent and were unable to answer the questionnaire were excluded from the study. some parameters were analyzed as risk factors for pain during biopsy, such as age, race, education level, serum psa, free - psa and the free - psa / total psa ratio, rebiopsy, biopsy indication, and prostate volume. complications such as hypotension, hypoxia, hemorrhage, urinary retention, and vasovagal reaction were also recorded. the biopsy procedure was performed on an outpatient basis. a structured room with all the equipment required for urgent care and emergency care was necessary (oxygen supply, laryngoscope, endotracheal tubes, respirator, defibrillator, and drugs). three minutes before the procedure, 50 g of fentanyl citrate dissolved in 1 ml of distilled water and 5 mg of midazolam dissolved in a 1-ml distilled water bolus were administered in separate syringes intravenously in the upper left limb with a number 23 butterfly needle. the procedure was performed with a 250-ml rectal enema and prophylaxis by administration of antibiotic ciprofloxacin 500 mg orally 2 hours before the procedure and after 8 hours. the procedure was performed with the use of a transrectal probe with the patient in the left lateral decubitus position with the thighs flexed. after the procedure, the patients remained in the recovery room until they could be discharged. in the immediate biopsy recovery period, all patients were evaluated by a single investigator responsible for measuring the primary pain outcome by use of a visual analogue scale (vas). the vas was used to evaluate the pain generated by the transducer introduction (vas 1) and the pain generated by biopsy (vas 2). after 7 days, the patients were evaluated again for the presence of pain (vas 3). pain was classified as follows : absence of pain, score of 0 ; mild pain, score of 0.1 to 3 ; moderate pain, score of 3.1 to 7 ; and severe pain, score from 7.1 to 10. data were collected by use of a microsoft excel spreadsheet (microsoft co., redmond, wa, usa) and were analyzed by using sas ver. results were expressed as means and standard deviations (sds) for age, psa, prostate volume, and pain. qualitative variables were described by frequency and percentage. to determine differences in pain levels among age, educational level, race, prostate volume, prebiopsy, rebiopsy, and anxiety, the kruskal - wallis test and wilcoxon rank - sum test were used when comparing two or more than two samples, respectively. in all tests, biopsies were performed in 118 patients, and of these, 56 patients (47.9%) had undergone at least one procedure. the average age, total psa, prostate volume, education level, and race of the patients are shown in table 1. of the 118 patients studied, 69 (58.4%) reported anxiety in the exam and 56 (47.4%) reported no anxiety. the average (sd) pain vas 1 was 1.951.98 mm. at this time, 75% of the patients reported pain lower than 3.1 mm, or mild pain. pain assessment during the introduction of the probe for biopsy (vas 2) had a mean of 2.732.55 mm. at the time of the vas 2, 75% of the patients reported pain lower than 4.5 and 50% reported pain lower than 1.5, or mild pain. just 5.4% and 11% of the patients reported severe pain at vas 1 and vas 2, respectively. evaluation of pain in the weeks following the biopsy (vas 3) had a mean of 0.30.9 mm, whereas 75% of patients reported no pain. there were huge differences among vas 1, 2, and 3 with high significance (vas 2>vas 1>vas 3, p=0.0013). pain intensity at different times (vas 1, vas 2, and vas 3) was compared with stratification by age, race, educational level, and other possible influencing factors such as prostate volume, rebiopsy, prebiopsy anxiety, and prostate cancer diagnosis. none of these factors had a significant influence on the pain level with this kind of sedoanalgesia. the main complications were rectal bleeding (21 patients, 17.7%), vasovagal reaction (5 patients, 4.2%), urinary retention (8 patients, 6.7%), urethral bleeding and fever (1 patient, 0.8%), pain (14 patients, 11.8%), hematuria (75 patients, 63.4%), and hemospermia (51 patients, 43.2%). of 14 patients who reported moderate to severe pain during the procedure, it was necessary to use a double dose to perform the procedure in 11 (78%). there were no respiratory or cardiac complications, even in elderly patients who required an additional dose of medication (10 mg midazolam and 100 g fentanyl citrate). with the introduction of serum psa in prostate cancer screening, there has been a significant increase in the number of biopsies, which has consequently led to a better diagnosis. about 65% to 90% of patients report pain of moderate to severe intensity, and 20% do not repeat the examination. sextant biopsy was considered the method of choice for many years, but nowadays it is recommended to obtain at least 12 fragments to increase the tumor diagnoses. the high number of punctures increases the prostate cancer diagnosis, but pain, anxiety, and discomfort are proportional to the number of punctures. the main factors responsible for pain during the biopsy are anal discomfort generated by transducer insertion and as a result of the needle penetration in the rectal wall, prostatic capsule, and periprostatic tissue. other factors such as age, transducer size, and procedure time can affect pain intensity. some studies have shown that younger patients or patients with smaller prostates have more discomfort during the biopsy. additionally, prebiopsy anxiety or rebiopsy as a result of a prior biopsy procedure are mentioned as factors predisposing to a higher pain intensity. we did not observe that these factors affected the pain scores, which may have been the result of the excellent analgesia and sedation obtained by the drugs used. in our research, there was no control group, because it is not ethical to perform this design without analgesia. even if there were risk factors involved in providing pain relief, this method of sedoanalgesia alleviated pain regardless of the presence or absence of these factors. although the best means of analgesia for prostate biopsy has not yet been defined, several techniques have been described in the literature. several studies have shown that one of the benefits of ppnb is to reduce pain safely in prostate biopsy. because of these indicators, ppnb is considered the standard analgesia procedure for prostate biopsy. however, patients still suffer significant emotional and physical discomfort before the procedure, which can increase the pain stimulus. moreover, ppnb does not act in the pain mechanism generated by the anal stretching that occurs when the rectal probe is introduced. therefore, we believe that the use of intravenous sedation and analgesia is the most effective method for controlling pain during prostate biopsy. this method of analgesia can optimize the benefits of the ppnb and may directly interfere in the anxiety and pain sensation caused by anal stretching from the transducer. these beneficial effects of intravenous sedation and analgesia are important considering that the number of prostate biopsies has been growing steadily, especially in economically active young patients, and also that biopsy may be repeated several times in the same patient including a larger number of fragments (16, 20, or 24 fragments). the drug used should preferably be rapidly metabolized with few side effects and, if necessary, be easily reversed. we do not doubt that sedoanalgesia with the attendance of an anesthesiologist will have a higher cost than the cost of a urologist or radiologist performing the procedure alone. however, this kind of sedoanalgesia can be performed by the urologist in a structured room with a defibrillator, material for resuscitation, and airway intubation. despite the small number of patients in fact, the costs of sedoanalgesia and prostatic nerve block are similar. in our service, we do not work with anesthesiologists to perform sedation and analgesia. in the united kingdom, it is common to use nitrous oxide. however, the procedure requires the compulsory attendance of the anesthesiologist, which can be considered a drawback, because it increases the cost of the procedure. moreover, owing to nausea and vomiting as side effects, the patients must stay in the recovery room for up to 4 hours after the procedure. with the use of midazolam and fentanyl citrate, the patients could leave the recovery room on average 30 minutes after the procedure, which facilitated its logistics. some studies have evaluated the use of midazolam and meperidine for sedation and analgesia for prostatic biopsy. tobias - machado. conducted a randomized controlled trial comparing three different types of anesthesia (administration of 2% intrarectal lidocaine gel, ppnb, and sedation with a combination of midazolam and meperidine) to evaluate efficacy in reducing pain during prostate biopsy. in the ppnb group, 78.33% of the patients reported pain, with 86.7% reporting weak pain and only 3.33% reporting severe pain. no patient had unbearable pain, and compared with the control group, there was significant reduction in pain (p<0.001). in the group receiving sedation with midazolam and meperidine, 76% of patients reported some pain, and of these 81.6% had little or no pain ; only 4.99% reported severe or unbearable pain. compared with the control group, the pain reduction in the group receiving sedation with midazolam and meperidine was significant (p<0.001). recently, izol. published a study that evaluated three different analgesia techniques on prostate biopsy. pain intensity was assessed by vas graded in three stages : during biopsy (vas 1), immediately after the procedure (vas 2), and 1 hour later (vas 3). a total of 100 patients were randomized into 4 groups : group 1 (control), group 2 (periprostatic block with 2% lidocaine), group 3 (intrarectal lidocaine gel), and group 4 (sedation and analgesia with 2 mg midazolam and 2 g / kg fentanyl intravenously). in the group receiving sedation and analgesia with midazolam and fentanyl, a decrease in pain intensity in these three conditions (vas 1, vas 2, and vas 3) was observed. groups 2 and 4 were statistically significant compared with the group that received intrarectal lidocaine gel and the gel control group (p=0.0001). of 100 patients undergoing the procedure, only 1 patient (belonging to the group that underwent periprostatic block) presented with hypotension, which was quickly treated. the study concluded that the association of midazolam with fentanyl and ppnb are effective and superior to the other techniques to relieve pain. the authors recommended sedoanalgesia only in patients who do not tolerate pain, in saturation biopsies, and in patients who are allergic to lidocaine. in our study, the combination of midazolam and fentanyl citrate proved to be easy to apply, safe, and effective in reducing pain and discomfort both during and after the procedure. in our samples, the association of these two drugs proved to be an excellent method of analgesia and sedation. midazolam acts by promoting sedation, retrograde amnesia, and relaxation of the anal muscle tone, which is one of the mechanisms responsible for pain during the procedure. fentanyl, in turn, is a potent opioid analgesic drug during and after the procedure. we noticed that after the procedure, when the patients were discharged, some of them did not remember having undergone it, which must be due to retrograde amnesia promoted by midazolam. it is important to emphasize that midazolam promotes only retrograde amnesia without compromising cognition, which did not interfere in the evaluation of pain after the procedure. the evaluation of the patient before the procedure can be carried out in the questionnaire that is routinely given before the biopsy indication. in our previous experience, there is a contraindication to perform it in patients with low cardiac and respiratory reserve. the average time for patient recovery is either about 30 minutes or is not different from the care given to patients with the use of ppnb. complications due to the use of these drugs are very rare with similar rates [16 - 19 ]. when complications do occur, they can be circumvented because the procedure is performed in an appropriate and structured place by providers professionally trained and qualified to treat them. intravenous sedation and analgesia with midazolam and fentanyl citrate is a good method to reduce the discomfort and pain caused by prostate biopsy, even during probe insertion. | purposeto assess the pain intensity of patients administered midazolam and fentanyl citrate before undergoing transrectal ultrasound - guided prostate biopsy.materials and methodsthis was a study in patients with different indications for prostate biopsy in whom 5 mg of midazolam and 50 g of fentanyl citrate was administered intravenously 3 minutes before the procedure. after biopsy, pain was assessed by use of a visual analogue scale (vas) in three stages : vas 1, during probe introduction ; vas 2, during needle penetration into prostate tissue ; and vas 3, in the weeks following the exam. pain intensity at these different times was tested with stratification by age, race, education, prostate volume, rebiopsy, and anxiety before biopsy. pain was ranked according to the following scores : 0 (no pain), 1 - 3 (mild pain), 4 - 7 (moderate pain), and 8 - 10 (severe pain). statistical analysis was performed by using kruskal - wallis and wilcoxon two - tailed tests with a significance of 5%.resultspain intensity was not influenced by any risk factors. the mean vas 1 score was 1.951.98, the mean vas 2 score was 2.732.55, and the mean vas 3 score was 0.30.9, showing greater pain at the time of needle penetration than in other situations (vas 2>vas 1>vas 3, p=0.0013, p=0.0001, respectively). seventy - five percent of patients reported a vas pain scale of less than 3.1 or mild pain.conclusionsintravenous sedation and analgesia with midazolam and fentanyl citrate is a good method for reducing pain caused by prostate biopsy, even during probe insertion. |
a 30-year - old female patient reported to the outpatient department of vasantdada patil dental college and hospital, sangli with a chief complaint of gingival swelling on the right maxillary posterior region. the patient noticed a painless swelling 6 months ago, which was small in size initially, started growing gradually and reached the present size. the patient revealed a history of similar swelling in the same region 2 years ago. surgical removal of the mass had been attempted, however it had been unsuccessful due to heavy bleeding from the site. the patient showed unilateral port - wine stain on the right side of her face extending from the superior border of the upper lip to the bridge of the nose superoinferiorly and from the midline to the preauricular region anteroposteriorly since her birth. on clinical examination, the patient revealed about 33 cm sized solitary extraoral swelling on the right maxilla extending from the midline to the midpupilary line anteroposteriorly and from the superior border of the upper lip to the base of the nose superoinferiorly. intraorally, about 36 cm sized solitary swelling, reddish pink in color was found extending from the right central incisor to the third molar on the buccal and palatal gingivae of the maxilla. the swelling involved marginal, papillary, and attached gingivae, and had smooth surface. it was soft in consistency, non - tender on palpation, compressible, pulsatile and blanched on pressure. no bleeding on palpation was noted. the right maxillary first and second premolars showed grade ii mobility. 1). a provisional diagnosis of vascular lesion was given and the patient was subjected to radiographic examination. intraoral periapical radiographs showed coarse bony trabeculae and enlarged marrow spaces on the right maxillary anterior and posterior regions. widening of periodontal ligament space was seen with lateral incisor, first and second premolar and the first molar was supraerupted (figs. panoramic radiograph showed ill - defined, irregular area of bone destruction extending from the mesial surface of the left maxillary central incisor upto the mesial surface of the right maxillary canine. admission laboratory tests showed hemoglobin (hb) of 7.3 g / dl, a platelet count of 63,000 per mm, prothrombin time of 17 seconds, activated partial thromboplastin time of 35 sec, and international normalized ratio of 1.3. the patient was then given blood and platelet transfusions after which the blood investigations showed hemoglobin of 13.3 g / dl, platelet count of 1,96,000, prothrombin time 15 seconds, activated partial thromboplastin time of 28 seconds and international normalized ratio of 1.1. the diagnostic angiogram showed a high - flow vascular malformation supplied principally by the alveolar branch of the internal maxillary artery. surgical treatment of such lesion required extensive resection of the maxilla and might result in the dysfunction and disfigurement. ligation of the external carotid artery was not advisable, since many anastomoses promoted the rapid appearance of a collateral circulation. therefore, embolization which consisted of occlusion of the vessels which contributed to the lesion was considered. one year follow - up revealed a significant reduction of clinical symptoms and signs of the lesion without any further complications. avms are extremely rare conditions that can be fatal if left untreated.6 they are caused by disturbances in the late stages of angiogenesis, mainly abnormal differentiation of vascular system.10 vascular malformations can be subdivided further into high - flow and low - flow lesions.1,2 in the present case, angiography was performed which demonstrated a high - flow avm. most avms have a history that includes the presence of a vascular blush in the overlying skin in the childhood, which begins to expand more rapidly as the patient enters puberty or undergoes other hormonal changes. they may also reveal a history of trauma to the involved area prior to the notification of the lesion. bleeding, pain, and tissue destruction are often subsequent signs in avm.1,6 on physical examination, early avms may have an overlying vascular blush in the skin similar to an early port - wine stain. the teeth may be loose or may exhibit pumping movement when pressure is applied and released.1,3,4,6 avms can invade the skin where ulcerations and bleeding are common.1,11 some " high - flow " lesions may result in consumption coagulopathy, requiring transfusion therapy.12,13 multiple imaging modalities should be used to evaluate characteristics of avms such as size, flow velocity, flow direction, relation to the surrounding structures and lesion contents.2 there are no pathognomonic radiographic features to distinguish avms on plain radiographs. they may appear as bone erosion, sclerotic change, periosteal reaction or a cyst like radiolucent lesion. a sunburst effect, created by spicules radiating from the center, is often present.2,14 the lesions most often have a multiloculated appearance due to residual bone trapped around vessels. small radiolucent locules may resemble enlarged marrow spaces surrounded by coarse, dense, and well defined trabeculae. they may have a honey comb or soap - bubble pattern that is well demarcated from adjacent bone. the roots of the teeth in proximity of the lesion may show displacement or resorption. high - flow lesions tend to result in more destructive skeletal changes, appearing as moth - eaten and poorly defined areas of radiolucency.12 the radiographic differential diagnosis of these lesions include ameloblastoma, ameloblastic fiboma, odontogenic myxoma, central giant cell granuloma and metastatic malignant tumors.6 color doppler ultrasound examination can provide information about the flow velocity. the drawbacks of ct are considerable exposure to ionizing radiation and limited information about blood flow.2 angiography and mr imaging are the preferred imaging modalities.2,6,10,15 mri depicts the anatomic relation of the vascular lesion with adjacent organs and the flow velocity of lesions. it is useful for evaluating the lesions postoperatively.2 angiography is currently the gold standard for the determination of location and flow characteristics of vascular lesions. angiography is useful to determine blood vessels supplying blood to the lesion, and the relative venous out - flow characteristics, and the presence or absence of arteriovenous shunts.3 according to orbach, the angiographic features of avms include dilatation and lengthening of afferent arteries, early and preferential filling of shunts, delayed filling of associated normal arteries, early opacification of draining veins and rapid flow to collateral vessels.16 intentional transarterial embolization was originally described in 1969 by lalli and coworkers.17 treatment of vascular malformation with selective embolization procedure is currently highly recommended and often used. the purpose of the selective embolization is to abruptly cut off the blood supply of the lesion, reducing the risk of potentially massive and lethal blood loss after its rupture, enabling a more focused and selective surgical procedure with less morbidity and with maximal preservation of important structures.18 various materials can be used for embolization. permanent agents include silicone spheres, lyophilized dura, pva, isobutyl cyanoacrylate and stainless steel or platinum coils. pva was used in present case as it is nonabsorbable and denser than gelfoam.9 to conclude, vascular malformations represent some of the most difficult lesions to diagnose and treat. interventional radiography plays an essential role in diagnosis and management of such lesions. with the use of this technique, extensive surgical procedures can be avoided so as to avoid facial disfigurement and functional compromise. | arteriovenous malformations are extremely rare conditions in that can result from abnormalities in the structure of blood vessels, which may be potentially fatal. a 30-year - old female patient visited our hospital with a complaint of swelling on the right maxillary posterior gingiva along with the large port - wine stain on right side of face. on clinical examination, the swelling was compressible and pulsatile. radiographic examination revealed a lytic lesion of maxilla. diagnostic angiography revealed a high - flow arteriovenous malformation of maxilla which was treated by selective transarterial embolization of maxillary artery using polyvinyl alcohol particles. |
opioid narcotics are the cornerstone drugs for managing severe cancer pain, with or without adjuvant drugs. fentanyl is a synthetic opioid - agonist that primarily interacts with the mu - opioid receptor. transdermal fentanyl patches are designed to deliver fentanyl at a constant rate from a reservoir. there have been many studies on the efficacy and convenience of transdermal fentanyl patches for controlling both cancer pain and non - cancer pain [2 - 4 ]. compared with other opioids, fentanyl patches have been associated with better pain relief, less constipation and they enhance the quality of life. especially, these patches are a good choice for patients with dysphagia, changes of consciousness and those who need opioid rotation due to side effects. although it is well known that there is no upper dose limit when using opioids, high doses of opioids are commonly feared by physicians, patients and caregivers. we describe here a patient with advanced cholangiocarcinoma who obtained a good pain control with high doses of transdermal fentanyl for cancer pain. a 52-year - old man was referred to our hospital because of cancer pain that was 4/10 to 5/10 on a numeric rating scale (nrs). three months previously, he had been diagnosed with locally advanced cholangiocarcinoma at other hospital (fig. he was taking non - steroidal anti - inflammatory drugs due to his mild abdominal pain. his pain was mainly dull, being located in the right upper quadrant of the abdomen. the cancer pain diminished his appetite and it often woke him from sleeping at night. we initially prescribed tramadol (300 mg / day) and amitriptyline (10 mg / day), but his background pain was not effectively relieved. thus, we administered transdermal fentanyl patches (12.5 g / hr) for the background pain and oxycodone immediate release (oir) tablets for the breakthrough pain, and this treatment brought a dramatic improvement of his pain. yet after 10 days, the background pain was abruptly aggravated (6/10 on the nrs). the dose of fentanyl was gradually increased to 250 g / hr over 2 months and his pain became tolerable (2/10 on nrs). after about 4 weeks on this dose of fentanyl patch, his pain intensity became worse and it eventually reached up to 8/10 to 9/10 on nrs. on admission, we added oxycodone (20 to 200 mg / day) and increased the dose of amitriptyline to 40 mg / day, but the patient failed to obtain an analgesic effect. abdominal ct was done to find any unknown pain - relieving factors at that time, and the ct showed a severe intrahepatic ductal dilatation (fig. percutaneous transhepatic biliary drainage was performed at once, which did not relieve his pain. thereafter, he refused all invasive procedures, including celiac plexus block or epidural block. in the 2 weeks before the patient 's death, the dose of transdermal fentanyl reached 1,050 g / hr (fig. the patient obtained a good pain control (nrs 2/10 to 3/10) with no exacerbation of side effects. although most cancer pain can be relieved, effectively controlling the pain of cancer patients is often problematic. one of the reasons for this is related to the so - called opioidphobia by physicians, patients and caregivers. many clinicians are afraid that high - dose opioids may lead to respiratory depression and hasten the death of patients. however, studies describing the morphine dosage used for hospice patients demonstrated that high - dose morphine has a high safety profile and it does n't adversely affect the survival of the patients. for our case reported here, we mostly applied transdermal fentanyl patches for the cancer pain. we initially administered a 12.5 g / hr fentanyl patch for background pain that was 4/10 to 5/10 on the nrs, which brought about dramatic pain control. with time, however, the patient 's cancer pain was aggravated and the dose of transdermal fentanyl was gradually increased to 250 g / hr. when the patient 's pain intensity became worse (8/10 to 9/10 on nrs) in spite of being on 250 g / hr transdermal fentanyl, we added oxycodone tablets. several preliminary data suggested that partial opioid rotation and opioid combinations may be beneficial for patients with a poor analgesic effect after dose escalation. yet for our patient, adding the second opioid failed to achieve a good analgesic effect. the highest dose of transdermal fentanyl reported in the english medical literature was 3,400 g / hr (34 patches of 100 g / hr each), which used for a 58-year - old woman with neuropathic pain due to a pancoast tumor of the lung. however, this huge dose had no effect for relieving her from neuropathic pain. in our patient, we increased the dose of transdermal fentanyl to 1,050 g / hr (21 patches of 50 g / hr each) over 3 weeks after discontinuing the oxycodone. at this dose, the patient could obtain good pain control during the last 2 weeks of his life, with no exacerbation of side effects. to the best of our knowledge, we have reported here on the highest dose of transdemal fentanyl that was successfully used for a patient suffering from visceral cancer pain. the administered fentanyl dose was equianalgesic to about a 4,000 mg dose of oral morphine/24 hours. our experience suggests that if it is needed for controlling cancer pain, administering high - doses of opioids should not be feared. however, orally administering this dose of opioids inevitably requires a large amount of tablets to be taken daily, which may induce more side effects and make patients uncomfortable. therefore, high doses of fentanyl patches may be a good choice for those patients who need a megadose of opioids to control their cancer pain. | we describe here a patient who obtained a good analgesic effect with high - dose fentanyl patches for controlling cancer pain. a 52-year - old man was referred to our hospital because of severe cancer pain that was 7/10 on a numeric rating scale (nrs). he had been diagnosed with locally advanced cholangiocarcinoma 3 months previously. we prescribed weak opioids and an antidepressant, but his pain was not relieved. we introduced strong opioids (transdermal fentanyl patches for the background pain and a short - acting opioid for the breakthrough pain) and his pain was tolerable on 250 g / hr of fentanyl patches for 3 months. with time, however, his pain intensity became worse and this reached up to 8/10 to 9/10 on the nrs. percutaneous transhepatic biliary drainage was performed, which did not relieve his pain. we increased gradually the dose of transdermal fentanyl to 1,050 g / hr (20 patches). at this dose, the patient was mentally alert, with good pain control (nrs 2/10 to 3/10) and no exacerbation of side effects. to the best of our knowledge, we report here on the highest dose of transdermal fentanyl that has been successfully used for treating a patient suffering from visceral cancer pain. |
the decline in respiratory function of stroke patients is caused by reduced physical activity. the decline in cardiopulmonary function is related to reduced oxygen transport ability caused by extended bed rest after hospitalization1. this condition can cause stroke patients who require intensive rehabilitation to tire easily during aerobic activities requiring endurance, thereby restricting their performance of daily living activities. consequently, the success rate of rehabilitation drops because functional recovery is hindered2. in a study conducted by khedr.3 the results of analysis of lung function show only 50% of the values expected of normal adults4, 5. among the different types of training used to improve respiratory functions, inspiratory muscle training (imt) improves inspiratory muscle strength and endurance, regardless of damage to the inspiratory muscles, by applying loads to the diaphragm and the accessory muscles of the inspiratory muscles6. it was reported that imt performed by subacute stroke patients for six months improved lung function, maximal inspiratory pressure (mip), exercise tolerance, and pulmonary function indexes7. in a study conducted by britto.8 of chronic stroke patients, imt for eight weeks improved mip and inspiratory muscular endurance (ime). gollee.9 reported that neuromuscular stimulation of the abdominal muscles supported respiration and the application of simple surface stimulation to major paralyzed expiratory muscles induced even muscle contraction, thus helping to improve cough and forced expiration. it was reported that abdominal muscle stimulation improved respiratory functions during expiration, because the contraction of the abdominal muscles caused by stimulation induces increased coughing and directly increases mip to improve expiratory flow9. gollee.9 also reported that abdominal muscle stimulation could improve conditions in which respiratory rates increase because of decreased lung volume. abdominal muscle stimulation also improved lung function of paretic patients with decreased functional residual capacity (frc) and elastic recoil during inspiration9. previous studies have shown that among the methods used to improve the respiratory function of stroke patients, imt is an excellent intervention for improving inspiratory muscle strength and endurance7. in addition, abdominal muscle stimulation induced improvement in forced expiration of patients with nervous system disorders, showing decline in respiratory function caused by respiratory air passage obstruction or decreased forced expiration. the present study aimed to verity more efficient imt method, the imt used in clinics with abdominal muscle stimulation, and identify the effects of the new imt method on the improvement of the respiratory function of chronic stroke patients. the participants were eighteen stroke patients (11 males, 7 females) who voluntarily consented to participate in the study. they were randomly and equally divided into two groups : an experimental group and a control group. the experimental group received abdominal stimulation while performing inspiratory muscle training, and the control group only performed inspiratory muscle training. both groups performed the training 3 times per week, non - consecutively, for 4 weeks. the average age, height, weight, and body mass index (bmi) of the experimental group were 54.44 years, 159.86 cm, 63.68 kg, and 24.82 kg / m, respectively, and the average time since stroke onset was 40.55 months. the average age, height, weight, and body mass index (bmi) of the control group were 55.88 years, 158.7 cm, 62.32 kg, and 24.71 kg / m, respectively, and the average time since stroke onset was 46.22 months. the subjects of the present study were patients who had been diagnosed with stroke using computed tomography and had hemiplegia as a sequela of partial damage of the cerebral hemisphere. the following exclusion criteria were stroke patients who had had the disease for at least six month or were receiving physical therapy in hospital but not receiving any particular treatment for rehabilitation. lung - function was measured with a spirometer (chestgraph hi 101, chest m.i. lung function was examined three times, and the results of reliability were chosen for the analysis. the subjects maintained an upright sitting position, and the measurement values included fvc, fev1, the pef, and fef2575. changes in the diaphragm thickness were analyzed using ultrasonography (logiq 7, ge co., usa). for all subjects, the mid axillary lines between ribs 8 and 9 on both sides were checked in a standing posture, then the chest wall was perpendicularly illuminated by a linear transducer (5.014.0 mhz) in an upright sitting position to observe the region between rib 8 and rib 9 in 2d images. the diaphragm thickness was measured as the distance between two parallel lines that appear bright in the middle of the pleura and in the middle peritoneum. the distance was measured three times, and the average value was calculated10. the diaphragm thickness ratio (tr) the formula of enright.10 formula was used to obtain standardized diaphragm thickness ratios (tr). tr= (diaphragm thickness during mip maneuver of frc / mean thickness while relaxing at frc). abdominal stimulation was applied when the subject was sitting with 90 hip flexion. a functional electrical stimulator (microstim, medel gmbh, germany) the adhesive surface electrodes (protens electrodes 48 48 mm, biopro - tech inc, korea) were attached to the abdominal muscles (rectus abdominis muscle, lateral abdominal muscle)11, 12. the electricity used had symmetric biphasic rectangular waveforms, a pulse duration of 250 s, a frequency of 40 hz, a maximum output of 90 ma, and a stimulation intensity ranging from 10 to 30 ma. stimulation time per session was 20 minutes (current flowing time 5 seconds, no current flowing time 5 seconds, and gradient variation 2.5 seconds). using a threshold imt device (threshold inspiratory muscle trainer, respironics health scan, inc., usa) during an expiration after one inspiration, the patient pressed the current flowing switch with his / her hand on the non - paretic side to induce expiration while stimulation was applied to the abdominal region9. the therapist helped if a patient had difficulty pressing the switch because of a coordination disorder. for both othe groups, imt was identically performed with 30% of the maximal inspiratory pressure (mip) for 20 minutes per session, three times per week for four weeks, a total of 12 times. data obtained from the two groups of subjects were analyzed using spss 18.0 (spss inc. because of the small size of the study sample, non - parametric tests were used, and between - group comparisons were performed using the mann changes in lung function found after the four - week intervention are shown in table 1table 1. the values of the variables measured before and after the intervention (n=18)grouppre - testpost - testchangetr (paretic side)experimental1.740.272.160.29 0.420.28control1.720.332.000.24 0.280.25tr (non - paretic side)experimental1.750.281.990.280.230.33control1.820.302.050.370.220.27fvc (% predicted)experimental59.0321.8365.4415.096.419.77control62.6819.2962.6315.720.0517.21fev1 (% predicted)experimental59.1519.7474.8117.91 15.6514.74control72.2322.0173.1717.770.9418.16pef (% predicted)experimental41.7219.1967.5015.97 25.7726.47control52.9514.1750.8215.732.138.14fef2575 (% predicted)experimental71.5832.4092.9828.88 25.5429.62control97.1318.9695.0621.232.0719.20statistical significance, p0.05. tr= diaphragm thickening ratio, fvc = forced vital capacity, fev1=forced expiratory volume in one second, pef = peak expiratory flow, fef2575= forced expiratory flow between 25% and 75% of vital capacity. the comparison of comparing the number of changes between before and after the intervention in the experimental group and the control group revealed significant differences in fev1 and pef (p < 0.05). statistical significance, p0.05. tr= diaphragm thickening ratio, fvc = forced vital capacity, fev1=forced expiratory volume in one second, pef = peak expiratory flow, fef2575= forced expiratory flow between 25% and 75% of vital capacity after implementing abdominal stimulation during inspiratory muscle training in the experimental group and the control group, tr significantly increased on the paretic side (p < 0.05), but not on the non - paretic side. the comparison of changes between before and after the intervention in the experimental group and the control group revealed no significant difference on either the paretic side or the non - paretic side (table 1). kim13 reported that increase in the residual capacity or decrease in the lung volume of stroke patients causes weakening of the inspiratory muscle and the expiratory muscle. the muscles necessary for maintaining posture and the muscles that act during breathing are closely related. the difficulties of stroke patients in maintaining posture and their deteriorated trunk stability cause the weakening of the expiratory muscles that maintain posture13. because these expiratory muscles are weak, patients with abdominal muscle paresis, including stroke, experience inability to clean the air passage and are prone to respiratory infections14. therefore, gollee.9 suggested applying neuromuscular stimulation to the abdominal muscles to help the contraction of the major expiratory muscles and to increase expiratory flows and tidal volumes, in order to improve respiration function. the present study examined a method designed to combine imt with abdominal muscle stimulation to improve forced expiration. in order to examine the effects of the new imt method, the new method was performed by the experimental group, whereas only imt was performed by the control group. moreover, the abdominal stimulation was applied in order to strengthen the expiratory muscle in order to try to improve the cost and time efficiency of using imt devices with other types of devices, as well as to avoid interrupting subject s breathing patterm. enright.10 reported that when the effects of imt were checked in healthy adults, diaphragm thicknesses and tr at maximal inspiration showed significant increases after exercises lasting for eight weeks. a previous study that conducted imt for cystic fibrosis patients reported that diaphragm thicknesses and tr at maximal inspiration showed significant increases15. in the present study, the tr of the diaphragm on the paretic side showed significant increases in both the experimental group and the control group, consistent with the results of previous studies. the values of tr also increased on the non - paretic side although this increase was not statistically significant. sutbeyaz.7 divided subacute stroke patients into an imt group, a breathing retraining group, and a control group. they conducted interventions six times per week for six weeks and compared lung function among the groups. their results showed significant increases in fvc, fev1, fef2575, and maximal inspiratory pressure (mip), but no increase in pef in the inspiratory muscle - training group. in a study conducted by britto.8, mip and ime (inspiratory muscular endurance) were measured after imt, and showed significant increases. in a study conducted by enright.15, a group which performed imt showed significant increases in tlc (total lung capacity) and vc (vital capacity), but not in fvc and fev1. moreover, in a study conducted by fregonezi.16, the imt group showed no significant changes in fvc, fev1, or tlc. interpreting the results of these previous studies, although imt shows clear effects on tr, and mip, the effects of imt on lung function are inconsistent. in particular, we identified that the effects of imt are not strong enough to improve forced expiration. therefore, in the present study, in order to improve forced expiration, abdominal stimulation was applied during imt. our results show significant increases in fev1, pef, and fef2575 and the changes in fev1 and pef showed significant differences between the two groups. these results were similar to the results of a study conducted by cheng.17, who reported significant increases in fvc, fev1, and pef after applying abdominal stimulation for four weeks. in a study conducted by lee.18, stimulation was applied to the anterior and posterolateral regions of the abdomen. their results showed significant increases in fvc, fev1, and pef, which is consistent with the results of the present study. therefore, abdominal stimulation reeducates the expiratory muscles, improves muscle strength and endurance, and induces powerful contraction of the expiratory muscles through repetitive afferent stimulation of the abdominal muscles, thereby increasing intra - abdominal pressure, facilitating upward movement of the diaphragm and decreasing pleural pressure and lung volume, thereby improving expiratory and sputum discharge abilities17. if imt were performed by stroke patients with pulmonary function problems resulting from damage to the respiratory muscles caused by stroke and reduced exercise capacity, abdominal muscle stimulation would improve respiratory function. however, we admit this study had some limitations. the researchers conducted a four - week experiment, and due to the short period of experiment, it was difficult to examine the positive effects on lung function (fvc) of the experimental and control groups. for this reason, it will be necessary to conduct long term experiments that include a more comprehensive analysis of the impact of abdominal stimulation during imt intervention on chronic stroke patients. | [purpose ] the purpose of the present study was to verify a new method for improving respiratory functions by applying both abdominal stimulation and inspiratory muscle training (imt) to train the inspiratory muscle and the expiratory muscle simultaneously, to improve the efficiency of imt of chronic stroke patients. [subjects ] eighteen stroke patients were randomly assigned to an experimental group (n = 9) and a control group (n = 9). [methods ] the experimental group was administered imt with abdominal stimulation, and the control group was administered only imt. during the intervention period, the experimental group and control group received training 20 min / day, 3 times / wk, for 4 weeks. to examine the lung functions of the subjects, fvc, fev1, pef, and fef2575 were measured using an electronic spirometer. the diaphragm thickness ratio was calculated from measurements made with a 7.5-mhz linear probe ultrasonic imaging system. [result ] the experimental group and the control group showed significant increases in diaphragm thickness ratio on the paretic side, but not on the non - paretic side. with regard to lung function, the experimental group showed significant increases in fev1, pef, and fef2575. the changes between before and after the intervention in the two groups were compared with each other, and the results showed significant differences in fev1 and pef. [conclusion ] the present study identified that imt accompanied by abdominal stimulation improved the pulmonary function of chronic stroke patients. |
aseptic meningitis is a central nervous system infection that encompasses all types of leptomeninges inflammation of the brain, characterized by fever and meningeal symptoms with moderate, predominantly lymphocytic cerebrospinal fluid (csf) pleocytosis and with bacteriologically sterile cultures.1,2 aseptic meningitis is not caused by pyogenic bacteria, but can be caused by various conditions including infectious viral and nonviral,27 drugs, malignancy, and systemic illnesses.8 therefore, this term is no longer tantamount with viral meningitis, although the two often are used interchangeably.8 largely, viral infection is the most common form of aseptic meningitis and enteroviruses are the most common causes of viral aseptic meningitis.2,9 certain enteroviruses are more likely to cause meningitis outbreaks,10 while others are mostly endemic.9 other viral agents include the herpesviruses;9 human immunodeficiency virus (hiv) which causes sterile meningitis;11,12 and mumps13,14 are sometimes involved. however, aseptic meningitis occurs at all ages, especially during summer and early fall,1517 without racial differences.3 the illness tends to occur three times more in males than in females.8 the incidence of aseptic meningitis in the us has been reported as 11 per 100,000 person - years, compared to 8.6 per 100,000 for bacterial meningitis.18,19 the illness is responsible for 26,00042,000 hospitalizations each year in the us,20,21 and for 37 incidence cases per 10,000 hospital admissions among children in singapore.22 the severity of the clinical picture can be divided according to the primary brain structure involved. when the infectious agent primarily attacks the brain parenchyma, the clinical picture of severe encephalitis will be encountered with seizures, loss of consciousness and obtundation. when the inflammation is primarily of the meninges, a relatively milder syndrome of viral or aseptic meningitis is performed. in this case it is usually considered a benign disease,23 because of the low complications and complete recovery ; most people exposed to these viruses experience either no symptoms or mild symptoms, and they usually experience full recovery in 514 days after onset of symptoms.8 however, fatigue and lightheadedness may persist longer in some people. hence, there is a pathological and clinical linkage between the brain parenchyma and meninges and some degree of meningeal inflammation is found with encephalitis and vice versa. when the two structures are involved a mixed picture of meningoencephalitis is more appropriate and the prognosis is less encouraging. diagnosis is by exclusion of an infectious agent and other noninfectious causes such as central nervous system tumors, metastatic carcinomas, sarcoidosis, systemic lupus erythematosus (sle) and granulomatous angiitis, and by demonstrating a convincing temporal relationship between the time of ingestion of drugs and the onset of the patient s symptoms. the recurrence of symptoms after rechallenge strongly supports the diagnosis of drug - induced aseptic meningitis (diam). our patient developed a nearly identical clinical picture consistent with diam on two separate occasions and a picture of meningoencephalitis on the third episode shortly after the consumption of amoxicillin. however, our case strongly suggests that the description of meningoencephalitis is more appropriate in view of the presence of confusion, unresponsiveness, psychomotor slowness, cognitive disturbances, nuchal rigidity and unilateral right mild weakness of the limbs without pyramidal signs. hence, a high index of suspicion is needed to make an accurate diagnosis of diam. this descriptive study comes to shed light on the literature reviews on this rare idiosyncratic event which may occur after local or systemic drug administration ; and presents the seventh worldwide case report of amoxicillin - induce aseptic meningitis. we describe a clinical case of a patient whom we believe to have had amoxicillin - induced aseptic meningitis after receiving informed written consent form and authorization for publication. a 77-year - old male was admitted to our hospital with a history of 7 days of headache, chills, fever, and nuchal rigidity. there was associated mild phonophobia but no photophobia, vomiting, nausea, or other constitutional symptoms. he was treated before his admission by amoxicillin using two oral doses of 500 mg daily for 1 week following dental and gingival inflammation, the seventh day he awoke with the complaints that prompted hospital admittance. one day before his admission he stopped amoxicillin treatment. at his admission, past clinical history, physical examination, laboratory, lumbar puncture, and computed tomography (ct) the patient had a similar syndrome after a dental procedure a 3 months before this incident. he had received a 1-week course of postprocedure amoxicillin of 500 mg daily and had similar headache, fever, and chills during the entire course of treatment. he was nt admitted to the hospital, because he stopped taking amoxicillin and he felt spontaneous pain relief after taking symptomatic pain treatment. on examination, the patient had an oral temperature of 38.1c, with mild tachycardia (heart rate, 102 beats per min). neurological examination revealed normal findings, including a normal mental status, supple neck, and absent kernig s and brudzinski s signs. results of examinations of other systems (cardiac ; respiratory ; head, eyes, ears, nose, and throat ; and skin) were all normal. the patient s serum white blood cell (wbc) count was 11,900 cells / ml (normal range, 360011,200 cells / ml), with a differential of 79.6% neutrophils (normal range, 44%88% neutrophils) and 11.4% lymphocytes (normal range, 12%43% lymphocytes). results of urinalysis were within normal limits. lumbar puncture revealed a pleocytosis with 20 cells (80% mononuclear), raised protein concentration of 91 mg / dl and glucose level was normal. no bacterial, fungal micro - organism or serological signs of viral infection had been found. herpes simplex polymerase chain reaction and enterovirus csf polymerase chain reaction (pcr) were negative. ct of the brain was normal and it was performed for excluding alternative diagnosis in certain situations. amoxicillin was stopped and changed with intravenous (iv) ceftriaxone (ctrx) for 10 days due to suspected partial untreated meningitis. six months after his first admission, he was admitted again with severe complaints of : headache, confusion, unresponsiveness, psychomotor slowness, cognitive disturbances, nuchal rigidity, and unilateral right mild weakness of the limbs without pyramidal signs and oral temperature of 38.3c. the patient s son proclaimed that his father was under amoxicillin treatment for 4 days following a tooth problem, and had a fever 1 day after initiation the treatment. on examination our patient showed psychomotor slowness, cognitive disturbances, nuchal rigidity and unilateral right mild weakness of the limbs without pyramidal signs. lumbar puncture revealed a pleocytosis with 12 cells (70% mononuclear), raised protein concentration of 117 mg / dl, and normal range of glucose. ct of the brain was normal and electroencephalography (eeg) showed intermittent diffuse slow waves abnormality in the theta range. control lumbar puncture after 2 days of admission was performed and showed 80 wbc (86% mononuclears) and proteins level were 96 mcg / dl. the patient improved without any specific treatment, his general condition including mental status and a focal neurological sign improved significantly and after 6 days was discharged. three weeks later the patient underwent complete medical examinations including csf and cognitive exams, all the exams were normal. according to these three repeated episodes, in which two were confirmed to be aseptic meningitis after repetitive negative culture results for viral, bacterial and fungal micro - organisms, and resolved with cessation of amoxicillin therapy, amoxicillin was the etiology of the two episodes of aseptic meningitis in this patient. to our knowledge, amoxicillin - induced aseptic meningitis has been reported only six times in the literature ; the last report was in 2008, and this will be the seventh well documented case report dealing with such a severe side effect of a widely and popular antibiotic. several methods, procedures and assays are needed to establish fast and accurate diagnosis of aseptic meningitis. it is important to obtain a careful history of medical disorders such as systemic lupus erythematosus, the most frequent underlying condition associated with diam.3 in addition it is important to make inquiries about recent vaccinations that may be implicated in the development of aseptic meningitis.24 it should take into account that patients who have diam, the typical csf profile reveals a neutrophilic pleocytosis, with several hundred to several thousand white blood cells per microliter ; normal glucose levels ; and variably elevated protein levels.2,25 results of csf gram stain and cultures are negative, and lymphocytic or eosinophilic pleocytosis may occur. different tests include : laboratory diagnosis ; pcr assay and variants reverse transcription polymerase chain reaction (rt - pcr) and multiplex pcr ; procalcitonin (pct) ; viral isolation ; serology and sometimes imaging are needed for adequate diagnosis of aseptic meningitis. many studies demonstrate the convenience of the application of the molecular assays in the laboratory diagnosis of the meningoencephalitis of different etiology. besides this, it is also a very valuable tool for the clinical management of the patients and for the execution of the epidemiological studies.26,27 routine csf enterovirus - specific polymerase chain reaction (ev - pcr) testing has been shown to reduce length of hospitalization in pediatric patients with suspected aseptic meningitis.2830 analysis of c - reactive protein (crp) levels also may be helpful in distinguishing bacterial- from drug - induced aseptic meningitis because crp levels are usually highly elevated in bacterial meningitis compared with diam.31,32 in our case report different diagnostic studies were performed, in addition to complete medical history, physical examination and ct, the diagnostic work included blood and csf examination and serology for infectious meningitis, viral culture of throat and rectal specimens was conducted in addition to serological tests for enteroviruses followed by herpes simplex pcr and enterovirus csf pcr. diam still relatively infrequent but probably more frequent than the literature report ; especially in our era where, the usage of different antibiotics ; the list of medications that cause diam continues to increase and currently includes a wide variety of medications.2,3,3358 diam continues to cause a clinical dilemma, because it can present as any other type of meningitis. also, the empirical treatment may, in fact, be the offending agent ; further confusing the physician involved in the care of the patient with diam. many classes of medications have been reported to cause diam, typically in patients known to have systemic lupus erythematosus.3 the most common drugs are nonsteroidal anti - inflammatory drugs, antibiotics, intravenous immunoglobulin, and muromonab - cd3 monoclonal antibodies46 of the antibiotics, the most commonly reported offending agents include many antimicrobials, such as trimethoprim - sulfamethoxazole, ciprofloxacin, cephalexin, metronidazole, amoxicillin, penicillin, and isoniazid, are causes of aseptic meningitis. in addition, the xanthine oxidase inhibitor allopurinol has been implicated in causing aseptic meningitis. diam is a complication in which numerous other drugs, namely ranitidine, carbamazepine, vaccines against hepatitis b and mumps and okt3 monoclonal antibodies (ie, directed against the t3 receptor and, therefore, pan t - cell antibodies), co - trimoxazole, radiographic agents, and muromonab - cd3, also have been associated.2,3,3340 amoxicillin is a moderate - spectrum, bacteriolytic, -lactam antibiotic used commonly to treat bacterial infections caused by susceptible micro - organisms. it is usually the drug of choice within the class because it is better absorbed, following oral administration, than other -lactam antibiotics. notwithstanding the wide use of this antibiotic, indeed, amoxicillin - induced aseptic meningitis has been reported only six times in the literature ; the latest report was in 2008.32,42,43,5961 although there has been speculation of a type 3 hypersensitivity reaction as a possible mechanism of amoxicillin - induced aseptic meningitis, a study by wittmann and kastenbauer,62 found no evidence of involvement of type 1 or type 3 reactions. regardless of its low frequency, aseptic meningitis is increasing and it can mimic an infectious process as well as meningitis that are secondary to systemic disorders for which these drugs are used. therefore, it should be included in the differential diagnosis of aseptic meningitis, particularly if aseptic meningitis develops in association with the use of nonsteroidal anti - inflammatory drugs (nsaids)4,63 or other offending drugs and if clinical recovery is rapid following cessation of the drug or if results of viral studies are negative. indeed, the diagnosis of diam is made by establishing a chronological relationship with the administration of the drug, onset of clinical symptoms and rapid resolution of the syndrome after drug withdrawal. the present case again helps shed some light on rare, morbid events that are attributable to commonly prescribed medications. because clinical characteristics of diam mimic those of infectious or other types of meningitis, physicians must continue to take thorough histories and be aware of the various medications that could cause these illnesses. we conclude that a thorough history on prior drug intake must be conducted in every case of meningitis, with special focus on those aforementioned drugs. if there is a suspicion of diam, a third - generation cephalosporin seems a reasonable treatment option until csf cultures are available. we should keep in mind these recommendations : quick resolution of symptoms is an important sign that distinguishes diam from viral meningitis, in which recovery usually requires 10 to 14 days. the diagnosis of diam is made by establishing a temporal relationship with the administration of the drug and onset of clinical symptoms and rapid resolution of the syndrome after drug withdrawal.csf glucose levels are usually normal in diam, which may help in differentiating it from bacterial meningitis in which glucose levels usually are low.analysis of crp levels also may be helpful in distinguishing bacterial from diam because crp levels are usually highly elevated in bacterial meningitis compared with diam. quick resolution of symptoms is an important sign that distinguishes diam from viral meningitis, in which recovery usually requires 10 to 14 days. the diagnosis of diam is made by establishing a temporal relationship with the administration of the drug and onset of clinical symptoms and rapid resolution of the syndrome after drug withdrawal. csf glucose levels are usually normal in diam, which may help in differentiating it from bacterial meningitis in which glucose levels usually are low. analysis of crp levels also may be helpful in distinguishing bacterial from diam because crp levels are usually highly elevated in bacterial meningitis compared with diam. the clinical features of almost all cases of amoxicillin - induced aseptic meningitis reported in the table 1 are similar. all patients who have amoxicillin - induced aseptic meningitis typically present with fever, headache, and stiff or rigid neck. the time between use of the amoxicillin and onset of the signs and symptoms ranged from 2 to 7 days after drug ingestion. diam is a diagnosis of exclusion, and clinical signs and csf findings vary greatly. clinical symptoms and csf findings in patients with diam were indistinguishable from the early stage of infections of the cns. detailed anamnesis was essential, particularly related to medication used immediately prior to the appearance of symptoms of cns impairment. hence, the diagnosis of diam was done by establishing a temporal relationship with the administration of the drug and onset of clinical symptoms and rapid resolution of the syndrome after drug withdrawal. in patients who have amoxicillin - induced aseptic meningitis, the typical csf profile reveals a neutrophilic pleocytosis, with several hundred to several thousand white blood cells per microliter ; normal glucose levels ; and variably elevated protein levels. amoxicillin - induced aseptic meningitis was reversible, with most signs and symptoms resolving within 24 to 48 hours after the drug were discontinued. | meningitis is usually produced by an infectious agent, but there are multiple noninfectious causes. drug - induced aseptic meningitis (diam) is an important entity and has been reported as an uncommon adverse reaction with numerous agents. thus, diam constitutes a diagnostic and patient management challenge. we present a patient with three episodes of aseptic meningitis due to amoxicillin, and then review the literature on this rare idiosyncratic event which may occur after local or systemic drug administration. a 77-year - old man was admitted to our hospital with fever, headache, and neck stiffness. seven days before admission he had a dental and gingival inflammation. he was treated with two oral doses of 500 mg daily of amoxicillin for one week. the seventh day he awoke with the complaints that prompted hospital admittance. amoxicillin was stopped 1 day before his admission. from his history we knew of two similar episodes : the first episode was after a dental procedure 3 months before this incident. he had received a 1-week course of postprocedure amoxicillin of 500 mg daily and had similar headache, fever, and chills during the entire course of treatment. he was nt admitted to the hospital, because he stopped taking amoxicillin and he felt spontaneous pain relief after taking symptomatic pain treatment. the second episodes was 6 months after his first admission, he had been admitted to our hospital with the same symptoms. amoxicillin was stopped and changed with intravenous (iv) ceftriaxone (ctrx) for 10 days due to suspected partial untreated meningitis. the patient improved rapidly within 2 days and was discharged from the hospital. on the basis of these three confirmed episodes of meningitis after recurrent exposure to amoxicillin, with repetitive negative testing for viral, bacterial, and mycobacterial micro - organisms, we diagnosed aseptic meningitis induced by amoxicillin. to our knowledge, this is the seventh well documented publication of such a severe side effect of a commonly used antibiotic. |
trauma accompanied by fracture of anterior teeth is an unpleasant experience for the patient who requires attention not only because of damage to the dentition, but also due to the psychologic effect of trauma. the majority of dental injuries involve the anterior teeth, especially the maxillary central incisors. a number of techniques have been reported in literature for rehabilitation of grossly mutilated teeth.[28 ] the aesthetic rehabilitation of patients with mutilated teeth generally involves a multidisciplinary approach. however, during the restorative procedures, negligence of periodontal tissues is of common occurrence, and is often the cause of failure. hence, it is essential to maintain a healthy periodontium and the biologic width while restoring teeth. the damaging effect on the periodontium of restorations with subgingivally placed margins is an important factor that needs to be considered during restorative treatments. crown lengthening can be performed by using various methods, and, orthodontic extrusion is regarded as the best method for lengthening of the clinical crown length. orthodontic extrusion has been referred to as slow eruption of teeth, which indicates that by utilizing light eruptive forces, the entire attachment apparatus can be shifted coronally in unison with the tooth. the main advantage of the orthodontic extrusion is that the root can be kept within the alveolus, thus the bone height is maintained without compromising the periodontal support. endodontically treated teeth with insufficient tooth structure are often restored with crowns. if there is insufficient dentin to support a restoration, a post - core is required to provide retention and support. the choice of an appropriate restoration for endodontically treated anterior teeth is guided by strength and esthetics. the cast gold post and core has been considered the gold standard because of its excellent success rate, favorable long - term prognosis, and ease of fabrication. traditionally, titanium, carbon, polyethylene fiber, and stainless steel posts have been used for the anterior region. however, when all - ceramic restorations are preferred, metal posts may negatively affect the esthetic results. with regard to both esthetic and health concerns, non - metal posts not only render esthetic superiority over metallic posts, but also preclude the possibility of corrosion and reduce the risk of toxicity. use of zirconia as a post - and - core material began in 1993 when introduced by meyenberg. the technique for milling a 1-piece zirconia post and core has been described by awad and marghalani and streacker and geissberger. computer - aided design and computer - aided manufacturing (cad / cam) milled zirconia posts and cores can be used when esthetic demands are important, and when the anatomy of the root canal and/or the extensive loss of the coronal tooth portion requires the use of a custom post. this technique also allows the possibility of completing a post and core in the same appointment. as stated in various reports, this technique provides a post and core with greater toughness, maximal adaptability to the canal, and adequate esthetics. here, we report a case of aesthetic rehabilitation of grossly destructed maxillary right central incisor using a multidisciplinary approach i.e. conventional endodontic treatment followed by orthodontic extrusion, and final restoration using cad - cam fabricated one piece milled zirconia post and core with full coverage zirconia crown. a 22 year old male reported to department of conservative dentistry and endodontics with the chief complaint of fractured maxillary right central incisor due to trauma 5 years back [figure 1a ]. on clinical examination, a grossly destroyed carious crown with minimal remaining dentin was present with tooth # 8 [figure 1b ]. preoperative intraoral periapical radiographs showed gross destruction of crown of # 8 with wide canal and periapical radiolucency and deep proximal caries with # 9 [figure 1c ]. pulp vitality tests (electric and cold tests) revealed that tooth # 9 was non vital. hence it was decided to restore the tooth with conventional endodontic treatment and post and core restoration. after excavation of caries it was seen that supragingival crown height both labially and palatally was 0.5- 1 mm. the crown : root ratio and occlusal clearance was adequate. hence in order to gain crown height for fabrication of a customized post and core with full coverage crown, it was decided to treat the tooth by forced orthodontic extrusion. the tooth was isolated under rubber dam (hygienic dental dam, coltne whaledent, germany). adequate endodontic access cavity was prepared after excavation of caries and working length radiograph was taken after initial identification of canal with # 15 k - files (kerr manufacturing co., romulus, mi). cleaning and shaping of the root canal was performed by using stainless steel file with a crown - down technique under copious irrigation with saline, 5.25% sodium hypochlorite solution (dentpro, chandigarh, india) and 17% ethylenediaminetetraacetic acid (edta) (glyde file prep, densply, france). in the next visit master cone the canal was finally rinsed with saline, dried and sectional obturation was performed using cold lateral compaction of gutta - percha using ah plus resin sealer (maillefer, dentsply, konstanz, germany) [figure 1d ]. an irm (caulk, dentsply, milford, de) temporary restoration was placed in the access cavity. (c) : preoperative diagnostic radiograph showing gross destruction of crown of # 8 with wide canal and periapical radiolucency and deep proximal caries with # 9. a lingual button was cemented on the tooth # 8, and 18 slot preadjusted brackets were cemented on teeth # 6, 7, 9 and 10 for controlled extrusion. an auxiliary 0.014 superelastic niti wire was overlaid on the stainless steel wire [figures 2a and 2c ]. a force of 40 - 50 gram was applied and extrusion was achieved after 4 weeks. the final crown height obtained labially and palatally was approximately 3 mm which was adequate for a crown ferrule and retention of the prosthesis [figures 2b and 2d ]. after active tooth movement was complete, the tooth was stabilized with fiber splints (polydentia, mezzovico, switzerland) for a period of 4 weeks for reorganization of periodontal tissues before fabrication of post and core [figure 3a ]. (d) radiograph showing orthodontic extrusion of maxillary right central incisor after four weeks of orthodontic treatment. (b) radiograph of the prepared post space in the root canal of the maxillary right central incisor of the patient. (c) and (d) direct impression of post and core by using pattern resin. at the following appointment, the root canal anatomy of maxillary right central incisor did not permit use of a conventional prefabricated glass fiber post, as the post diameter would not have allowed for good adaptation to the post space, and the resulting thick cement layer would have affected the bond strength, increasing the risk of mastication induced fracture [figure 3b ]. a cast gold post and core would have been the method of choice for this situation, but the metal color would have affected the translucency of a subsequent ceramic restoration. keeping the above factors in mind, cad / cam fabricated zirconia post and core and a ceramic crown were planned to restore the tooth. to gain adequate length for the post space, a portion of gutta - percha was removed with heated hand plugger (kerr manufacturing co., romulus, mi), such that the remaining gutta - percha at the apical portion was 5 mm [figure 3b ]. the post space was prepared using peeso reamer number three and four (dentsply maillefer, ballaigues, switzerland) to eliminate undercuts, because it was already relatively wide. a direct impression of the post space was made using pattern resin (gc america inc, alsip, il) [figure 3c ]. after impression of post space, core was also build up with pattern resin [figures 3d and 4a ]. an impression of the post space and adjacent teeth was made using hydrophilic addition silicone impression material (dentsply caulk, milford, usa) which was cast in type iv high - strength die stone (royal rock ; pemaco, inc, st. the direct resin pattern was digitized with a 3-dimensional (3-d) scanner (amann girrbach gmbh, pforzheim, germany) and the data were processed using cad / cam software [figure 4c ]. a digital 3-d model of the post and core was developed. a prefabricated zirconia block (amann girrbach gmbh, pforzheim, germany) was milled to develop the post and core [figure 4d ] with a milling machine (amann girrbach gmbh, pforzheim, germany). the milled ceramill zirconiumoxide frameworks were dense - sintered with the ceramill therm to obtain their final density and excellent material properties. the zirconia post and core was then wrapped with red, 8-m thick articulating paper and placed into the post space of cast to evaluate fit. after removal, interferences were relieved using a finishing diamond rotary cutting instrument in a high - speed handpiece (nsk, nakanishi inc, kamura, japan). post surface was air - abraded with 50-m aluminium oxide (al2o3) particles prior to cementation. the cementation procedure was then performed using a dual - cured resin cement (variolink ii, ivoclar vivadent) according to manufacturer 's instructions. (b) indirect impression of the post space and adjacent teeth using hydrophilic addition silicone impression material. (c) use of computer - aided design and computer - aided manufacturing (cad / cam) for data processing.. the temporary restoration was removed, and dentin was cleaned and conditioned with 37 c phosphoric acid for 15 seconds. this was followed by applying a dentinal adhesive (syntac adhesive, ivoclar vivadent) for 10 seconds and then dried. both the base and catalyst of the resin cement were then mixed and applied on the post surface as well as post space. after inserting the post into the canal, excess cement was removed, and polymerization was initiated using a polymerization lamp for 40 seconds [figures 5a, b and c ]. intraoral view of the cemented zirconia post and core (a) facial view (b) occlusal view. zirconia - based crown was fabricated by the same procedure as post and core [figures 5d, e and 6a ]. after the final zirconia crown [figure 6b ] was seated over the tooth, marginal fit was examined using a dental explorer. the cementation procedure for the crown was performed using the adhesive technique similar to that for the zirconia post [figure 6c ]. a periapical radiograph demonstrated that post and core remained well adapted to post space and there was a complete healing of periapical lesion [figure 6d ]. (a) computer - aided design and computer - aided manufacturing (cad / cam) view of zirconia coping. (d) radiograph of the maxillary right central incisor after 3 months of therapy demonstrating post and core in a well maintained condition and complete healing of periapical lesion. while placing a restoration it is important to maintain the biological width to avoid periodontal problems and ultimate failure of the restoration. in a healthy individual this width inber js was the first to suggest the use of forced eruption to treat non restorable or hopeless teeth. forced eruption allow the crown margins to be placed on the sound tooth structure while maintaining a uniform gingival contour that provides improved aesthetics without involving adjacent teeth. it also maintains acceptable crown - root ratio, biological width and good periodontal health. forced eruption is an excellent alternative to traditional surgical crown lengthening and surgical extrusion especially, in the anterior region of the mouth. surgical crown lengthening is contraindicated on aesthetic grounds and involves chances of violation of biological width compromising periodontal health. surgical extrusion also is a questionable tool, requires 4 - 6 months of healing period and the procedure is technique sensitive. the major limitation of forced eruption is the longer duration of treatment and a longer stabilization period (4 - 8 weeks). it is also contraindicated in an inadequate crown to root ratio, lack of occlusal clearance for required amount of eruption and periodontal complications. remaining tooth structure and tooth morphology, functional demands, arch position, periodontal status, and esthetics are few of these factors. various post systems are available ; however, 1-piece milled zirconia posts and cores can be used when esthetic demands are important and when the anatomy of the root canal and/or the extensive loss of the coronal tooth portion requires the use of a custom post. when restoring a severely damaged clinical crown with a wide post space, the 1-piece zirconia post and core can be well adapted and the cement layer thickness thus can be reduced. the modulus of elasticity of the 1-piece glass fiber post and core is similar to that of dentin, which limits stress concentration in the weakened root canal. the cad / cam systems offer advantage of automation of fabrication procedures with increased quality in shorter period of time. the primary disadvantages of cad / cam fabricated zirconia post and core are its relatively complex production process and high cost. this case report highlights the use of forced orthodontic extrusion and cad / cam milled zirconia post for rehabilitation of grossly destructed crown. forced orthodontic extrusion was selected as it maintains acceptable crown - root ratio, biological width, good periodontal health and aesthetic demand. other procedures like surgical crown lengthening and osteotomy have compromised aesthetic demand, inverse crown - root ratio, compromised function of adjacent teeth and the biological width maybe hampered. cad / cam milled zirconia post and core was selected because of the wide canal in this case with severe coronal destruction, and also as the use of zirconia post and core with all ceramic crowns optimizes the esthetic effect of the restoration. this clinical report describes a method of utilization of forced orthodontic eruption as an alternative to periodontal surgery, and a method for restoring a fractured anterior tooth with a 1-piece zirconia post and core milled with cad / cam technology. using this method, a precise fit of post and core this technique can provide a complete aesthetic rehabilitation of grossly destructed tooth without hampering the biological width, and thus has a better prognosis. as cad / cam and zirconia technology are relatively new eras of dentistry, they might undergo evolutionary changes in near future. | the aim of this study is to present a report of a case where forced orthodontic extrusion and computer - aided design and computer - aided manufacturing (cad / cam) technique was used for reconstruction of right maxillary central incisor with grossly destructed crown. aesthetic rehabilitation of a fractured maxillary right central incisor was performed employing a multidisciplinary approach i.e. conventional endodontic treatment followed by orthodontic extrusion and final restoration using cad - cam and one piece milled zirconia post and core with full coverage zirconia crown. after the procedure being completed, periapical radiographs taken at 3 month follow up period demonstrated that the post and core remained well adapted to post space and there was a complete healing of periapical lesion. this technique can provide a complete aesthetic rehabilitation of a grossly destructed tooth without hampering the biological width and thus has a better prognosis. |
anterior crossbite is a major esthetic and functional anomaly which has to be corrected at the onset in primary as well as mixed dentition to allow the normal development of occlusion. it is the lingual positioning of the maxillary anterior teeth in relation to the mandibular anterior teeth or lingo - occlusion of upper incisors or reverse over jet. etiological factors include trauma, supernumerary teeth, crowding, lip biting, over - retained, necrotic or pulpless primary tooth or root, delayed exfoliation of the primary incisors, and odontomas. functional crossbite or pseudo class 3 results from an early dental interference that forces the mandible to a more forward position to obtain maximum intercuspation. anterior and posterior crossbites in the early mixed dentition are believed to be transferred from the primary to the permanent dentition and can have long - term effects on the growth and development of the teeth and jaws. early treatment is directed with the following objectives : to prevent dysplastic growth of both dental and skeletal componentsto prevent excessive, abnormal wear of labial surface of maxillary and mandibular incisorsto avoid periodontal problems in mandibular incisors because of traumato alleviate functional posterior crossbite that can develop from cuspal interferences and mandibular shift that happens to accommodate the crossbiteto prevent habits such as bruxism resulting from improper occlusion, andearly treatment can re - establish proper muscle balance, thus prevents jaw muscles adjusting to the habitual posture of the mandible. to prevent dysplastic growth of both dental and skeletal components to prevent excessive, abnormal wear of labial surface of maxillary and mandibular incisors to avoid periodontal problems in mandibular incisors because of trauma to alleviate functional posterior crossbite that can develop from cuspal interferences and mandibular shift that happens to accommodate the crossbite to prevent habits such as bruxism resulting from improper occlusion, and early treatment can re - establish proper muscle balance, thus prevents jaw muscles adjusting to the habitual posture of the mandible. several orthodontic and nonorthodontic treatment options are available. nonorthodontic options include tongue blades, composite inclined planes, reversed stainless steel crowns, abnormally bulky restorations, and extractions followed by prosthetic replacement in older populations. other less common options include selective recontouring of teeth, surgically repositioning teeth, and segmental osteotomy of the affected teeth. orthodontic options include various removable acrylic appliances and fixed appliances with lingual springs and expansion screws. the name invisalign (align technology, inc., san jose, ca, usa) has given rise to various other similar techniques such as clear align and clear bite. kesling in 1946 described the concept of using a series of thermoplastic positioners to move teeth. align technology in 1997 introduced clear aligner technology. over the years, it has evolved and can correct many irregularities which were not possible with earlier appliances. basically, all these appliances use a series of clear aligners and move teeth in a series of 0.251 mm at a time and are worn from 7 to 14 days per tray according to different manufactures. initially, it was fabricated on stone casts which has given way to thermoforming and three - dimensional printing. the major drawbacks of clear aligners are the phenomenal costs and some limitations in tooth movement. when applying this science to anterior crossbite correction, it had the following limitations. the tray being thin (0.5 mm sheet) can not open the bite when done in maxillary arch alone. if both arches are done in some cases, it can be manageduse of thicker sheets is not possible to overcome this, as thicker sheets will not have elasticity and will impart larger forces. the tray being thin (0.5 mm sheet) can not open the bite when done in maxillary arch alone. if both arches are done in some cases, it can be managed use of thicker sheets is not possible to overcome this, as thicker sheets will not have elasticity and will impart larger forces. the solution is to sufficiently fabricate thin posterior bite plane in cold cure acrylic, finish it, and place it on the master cast and clear tray is fabricated over it. this case report documents a case of an anterior crossbite which was successfully corrected using modified clear tray aligners, which can be fabricated in our clinical setting. an 8-year - old girl reported to the department of pedodontics and preventive dentistry, with a complaint of irregular tooth in the upper arch. family history and health history were not significant and no known allergies were reported. on examination, there was a space deficiency of 2 mm mesiodistally for the tooth to get corrected. one was used as a study cast and the other three were marked as i, ii, and iii. a plan cut [figure 1b ] was made to separate the tooth to be moved from the base, one at a time [figure 1c ]. initially, the maxillary right central incisor was moved 0.5 mm distally and fixed with wax. then, the maxillary left central incisor was cut and moved 0.5 mm anteriorly and fixed with wax. later, the maxillary left lateral incisor was moved 0.5 mm distally and fixed with wax. model number two and three were cut and the tooth was moved to 1 mm and 1.5 mm so that each model will move the tooth 0.5 mm in a succession. all the models were finished using modeling wax to fill all the spaces created with cutting and moving the tooth. plan for tooth movement (a), v cut for separation (b), separated tooth (c), and teeth repositioned with wax (d) from these master casts, new impressions were made and models were prepared to serve as working casts. the acrylic was extended occlusally and about 1 - 1.5 mm buccolingually so that it will form an undercut and will lock into the tray material. this is placed on the cast and clear tray material of 0.5 mm was fabricated using thermoforming machine with vacuum. the bite plane gets nicely locked into the tray and will not be accidently dislodged when in use [figure 2b ]. the excess material were cut and finished and kept in marked packets to be given to the patient. all the models should be preserved till the end of the treatment so as to make any corrections during the treatment. posterior bite plane constructed (a), bite plane within the aligner (b), and models with tooth reposition (c) if a tray can not be inserted with moderate pressure, it means that the tooth has been moved in excess. in that case, another model can be created by pushing back the tooth slightly in the master cast, a working cast is prepared and another tray is created. thus, even if the tooth is moved in excess and the tray is not fitting, it is possible to correct it at any stage. the appliance has to be in position as much time as possible, except during meal time or consuming warm or hot liquids. the trays should be brushed gently along with the tooth brushing, twice a day. initially, the tray will be slightly tight on insertion, and light pressure should be used to seat it fully onto the teeth. the pain experienced during the initial few hours to a day or two will be due to the tooth movement. if the pain persists, if the tray can not be seated or the edges of the tray bruise the soft tissues, report to your dentist at the earliest and get the trays adjusted. the tray should be used for 7 days and progress to new set in the series. the appliance has to be in position as much time as possible, except during meal time or consuming warm or hot liquids. the trays should be brushed gently along with the tooth brushing, twice a day. initially, the tray will be slightly tight on insertion, and light pressure should be used to seat it fully onto the teeth. the pain experienced during the initial few hours to a day or two will be due to the tooth movement. if the pain persists, if the tray can not be seated or the edges of the tray bruise the soft tissues, report to your dentist at the earliest and get the trays adjusted. the tray should be used for 7 days and progress to new set in the series. after the first tray was used, the child experienced difficulty in inserting the second tray. to correct this problem, this was done by softening the wax in between the teeth with a warm wax knife and moving the incisor 0.25 mm behind so that it is positioned in between numbers 1 and 2. then, the cast was finished, an impression was made of the corrected master cast, and a new working model was prepared. this was labeled 1a and the original number 2 model will become number 2b [figure 2c ]. four clear trays were used to correct the crossbite successfully over a period of 4 weeks time figure 3a d, with the pre- and post - treatment pictures show an esthetically acceptable result [figure 4a and b ]. different aligners used for correction of the crossbite (a - d) preoperative (a) and postoperative (b) view of the maxillary anterior teeth a desire for cosmetic solution in search of comfortable and well - designed appliances than the bulkier ones has led to newer treatment modalities. transparent aligners are useful in space maintenance, space regaining, correction of crowding and spacing. they can also be used for arch expansion or constriction, anterior and posterior crossbite correction, and mild skeletal class 3 corrections. if more than three teeth require correction, it requires considerable expertise as it is easy to lose the track of the direction and distance, when the tooth is moved. if additional tooth movements such as extrusion or rotation are necessary, a small composite resin build - up (button) of 1 mm on the facial surface of the tooth should be made before the initial impression in the first appointment and will remain on the child 's teeth till the end of the treatment. this facilitates the tray to lock on to this button and will not allow the tray to slip, and in turn enables better tooth movement. otherwise, the tooth will not move appropriately to the desired position during extrusion or rotations. ideal forces vary from 35 to 60 g for tipping and 70 - 120 g for translation. hahn. recorded 282 - 542 g of force being applied for 1.51 mm of movement done. in comparison, invisalign uses 0.25 mm of movement per tray and uses new plastic called smart track, which is more resilient. drake. reported that though bodily protraction of the target tooth was programed during the fabrication of aligners, uncontrolled tipping resulted. duong and kuo compared the load deflection rates of nickel - titanium (niti) and stainless steel wires of 0.017 0.017 with 0.030 mm polyurethane material in vitro and found that the load deflection of the polyurethane was greater than the niti wire but less than the stainless steel wire. krishnan and davidovitch reported that the tooth targeted by clear aligner did not undergo the classic cycle of tooth movement as there is some amount of distortion of tray after wearing it for 1 - 2 days resulting in orthodontic forces tapering off. hence, even if slightly higher force is applied, it will not harm the tooth as the force will start diminishing after a day. use of thin sheets of 0.5 mm will result in optimal force applied to the teeth. care should be taken not to move the tooth more than 0.5 mm per tray as it will result in more force applied to the tooth as well as difficulty in insertion of the tray. esthetics and convenience has already emerged as the important factors in the acceptance of treatment as children have become very conscious of their appearance with the orthodontic appliances. modified tray aligners can be easily fabricated in clinic setting, which makes it very affordable. these aligners are transparent, comfortable, and easily tolerated and have only minimal or no speech disturbance | anterior crossbite results from the abnormal axial inclination of one or more anterior teeth. it is a major esthetic and functional anomaly which has to be corrected in the primary and early mixed dentition period to allow the normal development of maxilla and mandible as well as the occlusion. several treatment options are available to correct the problem. a unique appliance, modified transparent tray aligners was used to correct the anterior crossbite in an 8-year - old child. the clinical presentation, fabrication of the appliance, and the outcome are discussed. |
cancer is the third main cause of death in iran only after cardiovascular diseases and accidents (1). local reports also indicate that cancers is on the rise in iran (2). for example, a recent estimation indicated that lung, stomach, breast and prostate cancer increased between 2001 and 2015 in isfahan provenience in the centre of iran (3). due to increased number of cancer patients and limited resources, like many other developing countries, more attention has been paid to quantitative and physical criteria like increasing cancer patients survival or decreasing patients mortality rate (4). however, having cancer appears to be like a catastrophic experience that may have an impact on all aspects of individuals lives and their quality of life (qol) rather than only physical issues (5). qol is a concept used to emphasise that different aspects of individuals lives such as physical, psychological, and emotional are important in determining the experience of living and its quality and need to be taken into consideration by health care professionals when caring for those whose life is under threat (6). in addition, qol information can be used for screening and prioritising potential problems, facilitating communication with patients and identification of their preferences. patients can communicate their problems and priorities by filling out a qol questionnaire or through an interview. issues like sex life, personal relationships and financial issues, for example, are amongst those important matters patients usually do not express explicitly unless they are questioned. qol assessment can prompt the process of revealing hidden problems more appropriately and lead to more holistic care (7). amongst health care providers, nurses are intimately involved with cancer patients and their perception of cancer patients qol may be vital in order to be more helpful in their caring roles and to increase patients qol (8). this is particularly important in iranian oncology wards where nurses mainly have a bachelor of science qualification in nursing and significantly contribute in caring of cancer patients in a very busy oncology environment. due to the limited number of oncologists and their time limitations, they may rely on nurses to convey to them information about patients worries and concerns. in these situations so this voice needs to be accurate enough to convey to other health care professionals the broad spectrum of patients problems, needs, and expectations (9). a number of qol studies conducted to identify nurses understanding or nurses perception about cancer patients qol outside iran (10 - 13). however, the literature search for the research yielded no iranian research comparing nurses rating of patients qol with cancer patients rating of their qol. moreover, many of these research studies used qol tools developed in other countries including north america and u.k rather than the cross - culturally developed tools such as the world health organisation s quality of life brief questionnaire (whoqol - bref). this questionnaire was established across a number of cultures (including iran) and covers a broad spectrum of qol issues. the need for more research in this field in iran was further reinforced with the researcher experiences. the researcher has worked with cancer patients in different clinical situations, particularly chemotherapy and radiotherapy departments, for more than 20 years in and outside iran. such experiences brought to his mind that for many people affected by cancer, life during and after therapy is not just concerned with how long they live, but how well they live. these experiences encouraged the researcher also to consider more deeply if health care professionals particularly nurses have a holistic understanding of needs, expectations, and desires of patients who are living with cancer. given this, assessing nurses understanding or judgment about cancer patients qol is essential and worthy of exploration. the main purpose of this research study was therefore to identify nurses understanding of cancer patients qol in an iranian context. the secondary aim was to investigate the relationship between patients and nurses demographic and clinical variables and the level of agreement. the procedure of the study was derived from the similar research project that was completed by the researcher in australia in 2008. the study was conducted during a six month period in 2013 in syeed - al -shohada hospital affiliated to isfahan university of medical sciences, isfahan, iran. this hospital is an educative referral oncology centre that covers a varied number of patients from several provinces in iran particularly isfahan, chaharmahal and bakhtiari, kohgiluyeh and boyer - ahmad and lurestan. the research study was conducted in different medical - surgical oncology wards and an outpatient clinic. for purposes of measuring agreement between cancer patients and nurses, 50 pairs of cancer patients and their nurses were recruited to take part in the study using a convenient sampling (totally 100 patients and nurses). the sample of nurses selected based on consensus sampling which included more than 70 percent of eligible nurses in the hospital. patients were heterogonous in term of their health condition, disease severity and their treatments in order to generalise qol ratings to a broader sample of patients and nurses. in order to measure qol, this questionnaire consisted of 26 items which constituted four dimensions including physical (7 items), psychological (6 items), social relationship (3 items), and environmental (8 items). global quality of life and general health were also measured with two items which did not contribute in structure of none of domains. all 26 items were evaluated using a likert - type measure (e.g. ranging from very poor, to poor, neither poor nor good, good, and very good) (14). as the who group (14) stated, associations exist between qol domains of the whoqol - bref questionnaire with the original lengthy tool whoqol-100, range from 0.89 in the social relationship domain up to 0.95 in the physical domain. the total score of test - retest reliability is 0.75 for all domains which is above the acceptable level of 0.7. a population based study in iran also provided some preliminary evidences of reliability and validity of the farsi version of the whoqol - bref questionnaire (15). moreover, in another study with the whoqol - bref questionnaire in iran, findings supported the four domain structure of the questionnaire and its appropriate reliability (16). the questionnaire for nurses (proxy version- farsi) which was developed in the study was similar to that of patients with only small modifications made to qol items. for example, the item how satisfied are you with your health? in the patient version the whoqol - bref questionnaire was modified in the proxy version to how satisfied is the patient with his / her health? nurses were instructed to complete the survey specifically about the patient and the quality of life (qol) they believe this patient has considering all qol changes the patient might have. some other clinical and demographic information about patients (including age, gender, marital status, educational level, current cancer diagnosis, most common current treatment, treatment setting and patient performance status) and nurses (including age, gender, marital status, educational level, approximate contact time with patients, clinical experience, and how much nurses generally understand their patients qol) were also collected by the investigator. the researcher was interested to see how the daily living abilities of the patients might affect the patient - nurse agreement. therefore, the patients performance status were rated using the eastern cooperative oncology group (ecog) performance status scale, ranging from 0 (fully active) to 4 (completely disabled). patients with any type of cancer, with the age of 18 years or above and the capability to read and write in farsi (persian) were invited to take part in the study. qualified nurses were those providing nursing care for a selected patient and personally expressed that they understand that patient in a level to complete the questionnaire for him / her. the principal researcher or the assistant explained the aim and the process of the study to patients and nurses. if a patient presented a verbal agreement to take part in the study, the investigators gave the patient the whoqol - bref questionnaire- farsi to complete. the whoqol - bref (proxy version) was then completed separately by a nurse based on his / her perception of the patient s qol. the investigators supervised the study in a way that nurses did not ask any question directly from patients or their family. however, to facilitate nurses understanding about patients qol, they could review medical or nursing records. nurses mainly completed questionnaires on the similar day when patients filled it during work hours and their rest time. this research was approved by the nursing and midwifery care research centre of isfahan university of medical sciences. verbal information about the aim and the procedure of the study was provided for both patients and nurses and verbal consent was received. there was no need for patients or nurses to write their name on the questionnaires or forms. instead, the same number was recorded on all questionnaires and forms related to each pair of patient - nurse (including the whoqol - bref questionnaire completed by a patient, the whoqol - bref questionnaire- proxy version completed by a nurse for a patient, and clinical and demographic information forms) and all of them put in an envelope. after coding, the data were inserted into spss 12 software and qol mean domain scores for both patients and nurses were calculated. they were then multiplied by four so that results can be compared with scores derived from whoqol-100, giving domain scores ranging from 4 to 20. most patients were married (74.0%), male (56.0%), and under diploma was their highest level of education (59.6%). patients had a range of cancer diagnoses, with leukaemia (45.5%), colorectal cancer (18.2%), and non - hodgkin lymphoma (11.4%) being the most prevalent. the highest percentage of patients completing the questionnaire were from inpatient departments (92.0%), with chemotherapy (67.3%) as their major treatment. the highest percentage of patients (32.0%) were classified as restricted but ambulatory in their performance status. results also indicated that of 50 nurses who took part in the study, most were female (84.0%), and married (50.0%). nurses had a range of qualifications with bachelor of science in nursing (90.0%), nurse s aid (8.0%), and associate degree (2.0%) being the most prevalent. the mean age of nurses was 29.88 (6.38 sd) with a range of 22 - 47 years. the mean time nurses spent providing care for a given patient (hour / shift) was 2.19 (1.98 sd) hours with a range of 0.3 - 8.00 hours. the mean of nurses clinical experience was 5.91 years (5.74 sd) with a range of 0.5 - 23 years. the mean of nurses clinical experience with cancer patients was 4.25 years (4.72 sd) with a range of 0.5 - 23 years. in response to this question how much do you know the patient ? the majority of nurses (54%) stated that they knew their patients at a moderate level. the pearson correlations between different mean domain scores of patients and nurses are shown in table 1. the following criteria were used to judge about the outcomes of correlations : less than or equal to 0.20, poor ; 0.21 - 0.40, fair, 0.41 - 0.60, moderate ; 0.61 - 0.80, substantial ; 0.81 - 1, almost perfect (17). results indicated that there was a moderate significant correlation in the physical domain (r = 0.42, p < 0.002), a moderate significant correlation in the psychological domain (r = 0.50, p < 0.000), and a moderate significant correlation in the environmental domain (r = 0.58, p < 0.000). there was also a non - significant and fair correlation in the social relationship domain (r = 0.25, p = 0.09) between patients and nurses. the results of paired t - tests between physical, psychological, social relationship, and environmental domains of patients and nurses are reported in table 2. paired samples t - test values indicated that there were significant differences between physical qol mean domain scores of patients and nurses [t (49) = -3.41, p < 0.001 ]. there was not significant differences between patients and nurses in the psychological aspect [t (49) = 1.59 ], social relationship [t (49) = 0.18 ] and environmental [t (49) = -0.32 ] qol mean domains. in order to conduct multivariate analysis (standardised multiple regression), some demographic and clinical variables of patients and nurses that either significantly correlated with patient- nurse absolute differences at the bivariate level or were theoretically important, simultaneously entered into the equation. adjusted r - square was used to determine the proportion of variance in patient - nurse differences which could be explained by the patient and nurse combined (table 3). only few variables were identified to be significantly associated with the absolute difference between patients and nurses qol mean domain scores (being an indicator of agreement). however, using multivariate analysis indicated that patients performance status scale (= 0.345) was the only statistically significant predictor of differences between patient and nurse scores obtained for the physical qol domain scores. most patients were married (74.0%), male (56.0%), and under diploma was their highest level of education (59.6%). patients had a range of cancer diagnoses, with leukaemia (45.5%), colorectal cancer (18.2%), and non - hodgkin lymphoma (11.4%) being the most prevalent. the highest percentage of patients completing the questionnaire were from inpatient departments (92.0%), with chemotherapy (67.3%) as their major treatment. the highest percentage of patients (32.0%) were classified as restricted but ambulatory in their performance status. results also indicated that of 50 nurses who took part in the study, most were female (84.0%), and married (50.0%). nurses had a range of qualifications with bachelor of science in nursing (90.0%), nurse s aid (8.0%), and associate degree (2.0%) being the most prevalent. the mean age of nurses was 29.88 (6.38 sd) with a range of 22 - 47 years. the mean time nurses spent providing care for a given patient (hour / shift) was 2.19 (1.98 sd) hours with a range of 0.3 - 8.00 hours. the mean of nurses clinical experience was 5.91 years (5.74 sd) with a range of 0.5 - 23 years. the mean of nurses clinical experience with cancer patients was 4.25 years (4.72 sd) with a range of 0.5 - 23 years. in response to this question how much do you know the patient ? the majority of nurses (54%) stated that they knew their patients at a moderate level. the pearson correlations between different mean domain scores of patients and nurses are shown in table 1. the following criteria were used to judge about the outcomes of correlations : less than or equal to 0.20, poor ; 0.21 - 0.40, fair, 0.41 - 0.60, moderate ; 0.61 - 0.80, substantial ; 0.81 - 1, almost perfect (17). results indicated that there was a moderate significant correlation in the physical domain (r = 0.42, p < 0.002), a moderate significant correlation in the psychological domain (r = 0.50, p < 0.000), and a moderate significant correlation in the environmental domain (r = 0.58, p < 0.000). there was also a non - significant and fair correlation in the social relationship domain (r = 0.25, p = 0.09) between patients and nurses. the results of paired t - tests between physical, psychological, social relationship, and environmental domains of patients and nurses are reported in table 2. paired samples t - test values indicated that there were significant differences between physical qol mean domain scores of patients and nurses [t (49) = -3.41, p < 0.001 ]. there was not significant differences between patients and nurses in the psychological aspect [t (49) = 1.59 ], social relationship [t (49) = 0.18 ] and environmental [t (49) = -0.32 ] qol mean domains. in order to conduct multivariate analysis (standardised multiple regression), some demographic and clinical variables of patients and nurses that either significantly correlated with patient- nurse absolute differences at the bivariate level or were theoretically important, simultaneously entered into the equation. adjusted r - square was used to determine the proportion of variance in patient - nurse differences which could be explained by the patient and nurse combined (table 3). only few variables were identified to be significantly associated with the absolute difference between patients and nurses qol mean domain scores (being an indicator of agreement). however, using multivariate analysis indicated that patients performance status scale (= 0.345) was the only statistically significant predictor of differences between patient and nurse scores obtained for the physical qol domain scores. the main finding of this qol study was that there was generally a moderate agreement between each patient and nurse about a patient s qol in physical, psychological and environmental domains. similar to other research findings (10), correlation results indicated that nurses had lower agreement with their patients in qol domains such as the social domain. social relationship domain encompasses three items including having sex life, having friends, and having personal relationships. this is not surprising to see that, for example, nurses had a very low understanding of how patients have received support from their friends. there might also be barriers for nurses to ask patients about their sex life. unless a major issue exists in the patients sex life, it is not acceptable for nurses to query patients about their sex lives in such a context. comparison of qol mean domain scores of patients with nurses also showed that in contrast to other research studies (10), nurses in this study did not underestimate or overestimate patients qol, except for the physical domain. in this domain, which consisted of more objective items, nurses overestimated patients qol and considered patients as having fewer problems as their patients actually did. this might imply that nurses that participated in the study may not have enough assessment skills to truly understand physical issues and concerns of cancer patients. so these issues impact on nurses therapeutic relationships with patients and their role may not be as caring as it may be otherwise. this in turn may lead to unmet physical needs and decrease patients qol (18). if we consider qol as a gold standard to see if nurses have a holistic approach in their cares, results generally indicate that nurses need to improve their understanding of patient s qol (19). however, this issue also needs to take into the consideration that having a moderate understanding of patients qol may not be actually too bad as there might be reasonable justifications for differences in perceptions. firstly, qol has individualised meanings and nurses generally have difficulties understanding their patients personal perspective or definition of qol (18). secondly, nurses assessment of cancer patients qol in oncology wards such an assessment may not facilitate nurses developing a more holistic picture of cancer patients qol. time limitation, focus on care tasks, and discontinuity of care, might also work against nurses developing a more accurate understanding of cancer patients qol (7). the third reason that might justify differences between patients and nurses about cancer patients qol might be related to psychometric properties of the whoqol - bref questionnaire. while research findings indicated that the whoqol - bref questionnaire generally is a useful tool to measure qol, the reliability of the social relationship domain and the structure of domains of the questionnaire are challenged and recommended to investigated further in an iranian context (15). results of an exploratory factor analysis of the whoqol - bref questionnaire also stated that some items of the questionnaire loaded on different domains as what originally was proposed for the questionnaire (16). this might indicate that some small modifications might be necessary to conduct in social items to improve this tool to a more acceptable level for a qol assessment in an iranian context. therefore, it is suggested that the construct validity of the whoqol - bref be explored further in the clinical area of cancer patients in iran using factor analysis with a bigger sample size. the fourth reason that might justify the differences between patients and nurses perceptions is that the state of qol might change as individuals preferences, standards and goals are modified. so in order to measure qol more accurately, qol tools need to perform longitudinally and this is not always possible particularly in busy oncology wards. therefore, for a deeper understanding of patients qol, whenever possible, nurses need to make deep relationship and rapport with their patients rather than using only qol tools. using qol tools alone might marginalise some important issues and aspects which are important to individuals living with cancer (19). another important finding using multivariate analysis was that only patients performance status was identified to be a significant predictor of the level of agreement in the physical qol domain. in other words, as patients had more limitations in their daily activities, nurses became less successful to judge correctly about patients physical qol. the multivariate analysis also showed that in the physical domain, patients and nurses clinical and demographic variables together explained around 8% of variance in differences between patient - nurse scores. in other words, clinical and demographic variables investigated in the current study may not be considered as significant predictors of the level of agreement. in a research study by sneeuw. (20), several demographic and clinical variables of the patients and their significant others were found to be associated with the level of agreement using multivariate analysis. but they explained less than 15% of the variance in patient - proxy differences which was considered as a trivial proportion. given the fact that only 8% of variance in differences between patient - nurse scores was explained by clinical and demographic variables at the multvaraite level, it was necessary to investigate other clinical and demographic variables influencing the level of agreement. firstly, the study was conducted in very busy oncology wards with nurses having several tasks and in some cases this may have affected the patients and nurses responses to the questionnaire. secondly, although nurses ' response was very good, it is suggested that a similar study with a bigger sample size of nurses and patients be conducted to provide more generalizable results. thirdly, in this research study patients scores were considered as the best possible information available and nurses scores were compared with them. however, it can be argued that patients scores themselves are prone to some bias. therefore, nurses might be closer in their rating of patients qol with that of patients own rating in a real situation. differences exist between iranian cancer patients and their nurses about cancer patients qol that are far from the optimal level. this means that nurses may not have a holistic understanding of cancer patients qol. in order to minimize such discrepancies nurses need to enhance their relationship and rapport with cancer patients to underpin the assessment of cancer patients qol through various cues. as a result of such a well - developed relationship and rapport nurses might empathise with a number of issues, some of which are quite personal. while nurses develop their relationship skills, qol tools like the whoqol - bref questionnaire might also be useful in the clinical area to assess cancer patients qol more accurately. differences exist between iranian cancer patients and their nurses about cancer patients qol that are far from the optimal level. this means that nurses may not have a holistic understanding of cancer patients qol. in order to minimize such discrepancies nurses need to enhance their relationship and rapport with cancer patients to underpin the assessment of cancer patients qol through various cues. as a result of such a well - developed relationship and rapport nurses might empathise with a number of issues, some of which are quite personal. while nurses develop their relationship skills, qol tools like the whoqol - bref questionnaire might also be useful in the clinical area to assess cancer patients qol more accurately. | backgroundcancer is the third main cause of death in iran only after cardiovascular diseases and accidents.objectivesthe main aim of this research study was to identify nurses understanding of cancer patients quality of life (qol) in an iranian context.patients and methodsthis descriptive correlational study was conducted in an educative referral oncology center affiliated to isfahan university of medical sciences, isfahan, iran in 2013. 50 pairs of cancer patients and their nurses were conveniently recruited. the sample of nurses were selected based on consensus sampling which included more than 70 percent of eligible nurses in the hospital. patients and nurses were requested to complete the farsi version of the world health organization quality of life (whoqol - bref) questionnaire, separately. qol was measured across four dimensions including physical, psychological, social relationship and environmental.resultsthe qol mean domain scores of patients were 10.06, 11.88, 12.76 and 11.96, respectively. the corresponding scores of nurses were 11.6, 11.23, 12.65 and 12.07. pearson correlations between patients and nurses scores were 0.42, 0.5, 0.25 and 0.58 which revealed a fair to moderate agreement between nurses and patients scores in different domains. paired samples t - test values indicated that physical qol mean domain scores of patients were significantly lower than the corresponding drawings of nurses [t (49) = -3.41, p < 0.001].conclusionsthe main finding of this qol study was that nurses generally have a moderate understanding of cancer patients qol. therefore, in order to meet different physio - psycho - social needs of patients, nurses must enhance their understanding of patients qol particularly in more subjective and personal domains like social domain using a holistic approach. |
although anatomical liver resection is the standard of care for treatment of neoplastic hepatic disease (either primary or secondary), non - anatomical liver resections can still be useful in some situations. it is a low - morbidity technique that can be timely used for tumors near the hepatic surface. it also has become a useful tool after widespread implementation of neoadjuvant chemotherapy for hepatic metastasis, which many times reduces lesions dimensions to small non - anatomical hepatectomy offers the advantage of preserving hepatic parenchyma when compared with segment - oriented hepatectomy, being a safe option with good oncological results in patients with chronic hepatic disease and hepatocellular carcinoma and in the setting of staged hepatectomy in patients with multiple nodules [35 ]. despite being at first impression a very easy technique, one may face some difficulties while performing an enucleation of a tumor that is not visible at the hepatic surface. after proper localization of a small lesion with intraoperative ultrasonography and initiation of the transection of the parenchyma, the resulting bleeding and disruption of the hepatic tissue can easily make the tumor no longer visually identifiable if not recovered in the initial resected specimen, and further ultrasonography examination may not access the tumor after disruption of the hepatic tissue. this article describes a simple, efficient and low - cost maneuver to make enucleation of hepatic lesions not visible at the hepatic surface a precise and straight to the point technique. it consists of inserting methylene blue on the lesions by ultrasonographic guidance. based on preoperative image studies, the portion on the liver that contains the tumor is fully mobilized by transection of hepatic ligaments. then, intraoperative ultrasonography is performed in order to achieve precise localization of the lesion and estimation of its deepness (fig. 1). figure 1:hypoechoic 5-mm lesion at 2 cm depth (metachronous metastatic tumor from colorectal carcinoma) (arrow). hypoechoic 5-mm lesion at 2 cm depth (metachronous metastatic tumor from colorectal carcinoma) (arrow). under ultrasonography guidance, at this time, 5 ml of methylene blue is inserted, and the needle is retracted from the liver. the first result is that a small area around the tumor and the lesion itself will immediately change its echographic characteristics, becoming much more hyper - reflective and easily identifiable by ultrasonography (fig. figure 2:(a) methylene blue injection under ultrasonographic guidance and (b) easily identifiable methylene blue - injected lesion with hyper - echoic pattern (arrow). (a) methylene blue injection under ultrasonographic guidance and (b) easily identifiable methylene blue - injected lesion with hyper - echoic pattern (arrow). after that, glisson 's capsule is marked with cautery leaving a 2-cm margin. usually, transection is performed with bipolar forceps. during the transection, close to the depth previously defined, intraoperative ultrasonography is repeated, and a well - defined area containing the tumor and methylene blue will be identifiable, despite the disruption of the hepatic parenchyma (fig. 3). resection is completed and specimen checked to confirm the presence of the lesion inside. figure 3:after parenchymal disruption, hyper - echoic lesion still clearly by ultrasonography (arrow). after parenchymal disruption, hyper - echoic lesion still clearly by ultrasonography (arrow). if the tumor is not retrieved with the specimen, despite the bleeding caused by parenchymal transection, further inspection of the manipulated hepatic bed will disclose the presence of methylene blue, and under direct visualization of the area of the tumor, a second specimen is retrieved containing the lesion (fig. 4). figure 4:(a) methylene blue - injected area containing the tumor within the parenchyma and (b) two specimens : the smaller one, that was displaced deeper within the parenchyma, containing the tumor. (a) methylene blue - injected area containing the tumor within the parenchyma and (b) two specimens : the smaller one, that was displaced deeper within the parenchyma, containing the tumor. based on preoperative image studies, the portion on the liver that contains the tumor is fully mobilized by transection of hepatic ligaments. then, intraoperative ultrasonography is performed in order to achieve precise localization of the lesion and estimation of its deepness (fig. 1). figure 1:hypoechoic 5-mm lesion at 2 cm depth (metachronous metastatic tumor from colorectal carcinoma) (arrow). hypoechoic 5-mm lesion at 2 cm depth (metachronous metastatic tumor from colorectal carcinoma) (arrow). under ultrasonography guidance, at this time, 5 ml of methylene blue is inserted, and the needle is retracted from the liver. the first result is that a small area around the tumor and the lesion itself will immediately change its echographic characteristics, becoming much more hyper - reflective and easily identifiable by ultrasonography (fig. 2b). figure 2:(a) methylene blue injection under ultrasonographic guidance and (b) easily identifiable methylene blue - injected lesion with hyper - echoic pattern (arrow). (a) methylene blue injection under ultrasonographic guidance and (b) easily identifiable methylene blue - injected lesion with hyper - echoic pattern (arrow). usually, transection is performed with bipolar forceps. during the transection, close to the depth previously defined, intraoperative ultrasonography is repeated, and a well - defined area containing the tumor and methylene blue will be identifiable, despite the disruption of the hepatic parenchyma (fig. 3). resection is completed and specimen checked to confirm the presence of the lesion inside. figure 3:after parenchymal disruption, hyper - echoic lesion still clearly by ultrasonography (arrow). after parenchymal disruption, hyper - echoic lesion still clearly by ultrasonography (arrow). if the tumor is not retrieved with the specimen, despite the bleeding caused by parenchymal transection, further inspection of the manipulated hepatic bed will disclose the presence of methylene blue, and under direct visualization of the area of the tumor, a second specimen is retrieved containing the lesion (fig. 4). figure 4:(a) methylene blue - injected area containing the tumor within the parenchyma and (b) two specimens : the smaller one, that was displaced deeper within the parenchyma, containing the tumor. (a) methylene blue - injected area containing the tumor within the parenchyma and (b) two specimens : the smaller one, that was displaced deeper within the parenchyma, containing the tumor. it was first prepared by german chemist heinrich caro in 1876 and is on the world health organization 's list of essential medicines as one of the most important medication needed in a basic health system [6, 7 ]. it is described as the first fully synthetic drug used in medicine being used in the treatment of malaria since 1891 and is largely used in many clinical situations with safety.. however, non - anatomical wedge resections can be effective and have good oncological results especially in small metastatic lesions and has the advantage of sparing hepatic parenchyma, that is indispensable in patients with chronic hepatic disease or with severe chemotherapy - associated liver injury and in the setting of staged hepatectomies or in patients with multiple lesions [1, 9 ]. during the enucleation of a hepatic tumor not visible in the hepatic surface, after parenchymal transection, disruption of the hepatic tissue many times makes the tumor not visible any longer by repeat ultrasonography, which is often performed to check the depth of the transection. furthermore, if the specimen is retracted and the tumor is not present, the bleeding in the cutting line makes it difficult to find the tumor within the hepatic parenchyma. injecting methylene blue in the tumor overcomes both difficulties cited above. the lesion becomes much more hyper - echogenic at ultrasonography even after the parenchymal transection, and the tumor injected with methylene blue presents a great deal more visual contrast with the surrounding hepatic tissue, becoming easily identifiable if a first specimen was retracted not containing the lesion. this simple maneuver can make enucleation of hepatic tumors not visible at the hepatic surface an easier, faster and more precise maneuver. it presents the advantages of making the area of the tumor much more hyper - reflective at intraoperative ultrasonography even after hepatic transection and much more visually identifiable within the hepatic parenchyma after an initial specimen is retracted not containing the tumor and further resection is needed. | enucleation of hepatic tumors is a low - morbidity technique with adequate oncological results that is useful in many clinical settings. compared with anatomical liver resections, it offers the advantage of maximal hepatic parenchymal preservation. however, some technical adversities may occur during the enucleation of liver tumors, such as difficulty in finding the lesions by intraoperative ultrasonography after hepatic transection or further visually spotting the tumor within the parenchyma if a first specimen is retracted not containing the lesion. we describe an innovative technique that overcomes these possible adversities and makes the enucleation of liver tumors easier and more precise. |
the trauma of passing a large dialysis catheter through the vein wall is an important initiating stimulus for the fibrin sheath and subsequent fibrosis in the central vein (1). respirations, cardiac motion, and positional changes tend to move the indwelling catheter within the vein, and can probably damage the wall as well (2, 3). subsequent creation of an ipsilateral arteriovenous (av) access with the associated high flows, turbulence, and perivascular vibrations stimulate intimal hyperplasia and these sequence of events ultimately result in stenosis of the central vein (4, 5). surgical management options have high primary patency rates, but they are prone to significant morbidity associated with exposure of the deep veins, especially considering the poor health status of most hemodialysis patients (6). endovascular treatment options include percutaneous transluminal angioplasty (pta) and percutaneous transluminal stenting (pts). most studies on endovascular procedures for venous stenosis or occlusion in the hemodialysis patient have reported primary patency rates from 10 to 30% after 1 year (7 - 11). published outcomes with stenting for central venous stenosis and occlusions have primarily utilized the wallstent (boston scientific, natick, ma, usa) with 12-month primary patency rates below 31% (8, 10 - 12), though one study demonstrated 56% patency (13). a study by vogel and parise (14) using the smart stent (cordis, miami, fl, usa) demonstrated 67% primary patency for central venous stenosis at 12 months. depending on the density of the struts, stents can be classified as those with a closed - cell or an open - cell configuration (15). closed - cell stents are characterized by small free cell areas between the struts, whereas open - cell stents have larger uncovered gaps. closed - cell stents are less flexible and may develop kinks and incomplete expansion (16). conversely, stents with an open - cell configuration conform best to angulated vessels or tortuous anatomy. carotid artery stenting with different designs and configurations are available, but direct comparisons of open - cell versus closed - cell stents has rarely been performed in central vein stenosis or occlusions (16 - 18). the purpose of this study was to evaluate our outcomes following the use of an open - cell stent versus a closed - cell stent for patients with central vein stenosis or occlusions in hemodialysis patients and to compare long - term patency between the two groups retrospectively. the records of 2418 hemodialysis patients who underwent endovascular treatment for central vein stenosis or occlusion at gangneung asan hospital and soonchunhyang university hospital from 1997 to 2015 were reviewed. patients with central vein stenosis or occlusions successfully treated with balloon angioplasty alone were excluded. a 70% or greater stenotic lesion of the central veins with filling of the collateral veins was an indication for balloon angioplasty. stent placement was performed only if conventional balloon angioplasty was unsatisfactory, due to elastic recoil (> 30% residual stenosis and continued filling of collateral veins around the lesion) or occurrence of restenosis within 3 months after balloon angioplasty for the same lesion (19). when thrombus in the central vein was present, the treatment of choice was a primary stent placement. among them, 401 patients (200 males and 201 females ; mean age, 59.17 years ; range, 23 - 86) who underwent stent placement were enrolled in this study. case data were retrospectively retrieved from radiographic reports, angiographic images, and medical records. records were reviewed for the patient s age, sex, incidence of diabetes, hypertension, smoking, and age of dialysis access. radiographic records were reviewed for a history of previous angioplasty for the same lesion, location of venous stenosis or occlusion, and length and diameter of stents employed. the causes of chronic renal failure were hypertension (32.4%), diabetes mellitus (32.2%), glomerulonephritis (7%), tuberculosis (0.2%), systemic lupus erythematosus (0.2%), pregnancy - induced intoxication (0.2%), and unknown origins (27.8%). the clinical features of the patients whose central vein stenosis or occlusion was treated with an open - cell stent and those treated with a closed - cell stent are compared (table 1). abbreviations : avf, arteriovenous fistula ; avg, arteriovenous graft ; crf, chronic renal failure ; m, month ; pta, percutaneous transluminal angioplasty ; lt, left ; rt, right ; y : year values are presented as no. all patients underwent an initial diagnostic fistulography by 21 g needle into the outflow vein. the access circuit was evaluated via contrast digital subtraction fistulography from arterial anastomosis to the right atrium. intravenous (iv) fentanyl citrate and midazolam were used for sedation in patients who were agitated or who could not tolerate the pain during the procedure. two hundred fifty seven open - cell stents and 144 closed - cell stents were used. design and prototype of stents stent sizes varied from 10 to 24 mm in diameter, and 20 to 80 mm in length. open - cell stents with a diameter of 10 to 14 mm were placed in the study population. in closed - cell stents, the stents were dilated post - deployment to the appropriate size of the vein in all cases. the diameter of the stent was determined after a review of baseline angiography results and the stent length required was based on the extent and location of the lesion so that both ends of the stent could be extended to the adjacent normal vein. stents with a diameter 1 to 2 mm larger than that of the true vessel lumen were used for all devices. the computerized access database was used to review all 2418 fistulography performed during the 14-year period from july 1997 to february 2011 retrospectively for central vein stenosis or occlusion in the hemodialysis patient. technical success was defined as a restoration of flow in the hemodynamic access with less than 30% residual diameter stenosis for the underlying central venous lesion treated and decreased collateral circulation (19). primary patency was defined as the time interval from initial stent insertion to the next percutaneous intervention for central venous stenosis or occlusion (19). procedure time was defined as the time interval from the start of percutaneous puncture through the final post - treatment angiogram (19). clinical evaluation and fistulography a statistics software package (spss, version 14.0, spss) was used for statistical analysis. kaplan - meier method was used to calculate the cumulative probability of patency and mean patency. for analysis of categorical variables, the log - rank test was used to compare the patency between the two groups. the records of 2418 hemodialysis patients who underwent endovascular treatment for central vein stenosis or occlusion at gangneung asan hospital and soonchunhyang university hospital from 1997 to 2015 were reviewed. patients with central vein stenosis or occlusions successfully treated with balloon angioplasty alone were excluded. a 70% or greater stenotic lesion of the central veins with filling of the collateral veins was an indication for balloon angioplasty. stent placement was performed only if conventional balloon angioplasty was unsatisfactory, due to elastic recoil (> 30% residual stenosis and continued filling of collateral veins around the lesion) or occurrence of restenosis within 3 months after balloon angioplasty for the same lesion (19). when thrombus in the central vein was present, the treatment of choice was a primary stent placement. among them, 401 patients (200 males and 201 females ; mean age, 59.17 years ; range, 23 - 86) who underwent stent placement were enrolled in this study. case data were retrospectively retrieved from radiographic reports, angiographic images, and medical records. records were reviewed for the patient s age, sex, incidence of diabetes, hypertension, smoking, and age of dialysis access. radiographic records were reviewed for a history of previous angioplasty for the same lesion, location of venous stenosis or occlusion, and length and diameter of stents employed. the causes of chronic renal failure were hypertension (32.4%), diabetes mellitus (32.2%), glomerulonephritis (7%), tuberculosis (0.2%), systemic lupus erythematosus (0.2%), pregnancy - induced intoxication (0.2%), and unknown origins (27.8%). the clinical features of the patients whose central vein stenosis or occlusion was treated with an open - cell stent and those treated with a closed - cell stent are compared (table 1). abbreviations : avf, arteriovenous fistula ; avg, arteriovenous graft ; crf, chronic renal failure ; m, month ; pta, percutaneous transluminal angioplasty ; lt, left ; rt, right ; y : year values are presented as no. all patients underwent an initial diagnostic fistulography by 21 g needle into the outflow vein. the access circuit was evaluated via contrast digital subtraction fistulography from arterial anastomosis to the right atrium. intravenous (iv) fentanyl citrate and midazolam were used for sedation in patients who were agitated or who could not tolerate the pain during the procedure. two hundred fifty seven open - cell stents and 144 closed - cell stents were used. stent sizes varied from 10 to 24 mm in diameter, and 20 to 80 mm in length. open - cell stents with a diameter of 10 to 14 mm were placed in the study population. the stents were dilated post - deployment to the appropriate size of the vein in all cases. the diameter of the stent was determined after a review of baseline angiography results and the stent length required was based on the extent and location of the lesion so that both ends of the stent could be extended to the adjacent normal vein. stents with a diameter 1 to 2 mm larger than that of the true vessel lumen were used for all devices. the computerized access database was used to review all 2418 fistulography performed during the 14-year period from july 1997 to february 2011 retrospectively for central vein stenosis or occlusion in the hemodialysis patient. technical success was defined as a restoration of flow in the hemodynamic access with less than 30% residual diameter stenosis for the underlying central venous lesion treated and decreased collateral circulation (19). primary patency was defined as the time interval from initial stent insertion to the next percutaneous intervention for central venous stenosis or occlusion (19). procedure time was defined as the time interval from the start of percutaneous puncture through the final post - treatment angiogram (19). clinical evaluation and fistulography a statistics software package (spss, version 14.0, spss) was used for statistical analysis. kaplan - meier method was used to calculate the cumulative probability of patency and mean patency. for analysis of categorical variables, the log - rank test was used to compare the patency between the two groups. when analyzing across both open - cell stents group and closed - cell stents group, we found that a history of diabetes, hypertension, duration of chronic renal failure, and history of previous catheter insertion were significant in the open - cell stents group (table 1). considering the two groups collectively, the vessel most commonly treated was the innominate vein (n = 306), followed by the subclavian vein (n = 89), and jugular vein (n = 6). in the open cell - stent group, 205 innominate veins, 46 subclavian veins, and six jugular veins were involved, and in the closed - cell stent group, 101 innominate veins and 43 subclavian veins were involved. the author found 159 central vein stenoses, and 98 central vein occlusions in the open - cell stent group, and 78 central vein stenoses, and 66 central vein occlusions in the closed - cell stent group (table 3). there were 30 cases of thrombosis in the open - cell stent group, and 12 cases in the closed - cell stent group. one failure with an open - cell stent involved a successful stent placement, but coexistence of thrombosis in the graft site was not removed completely and the flow was insufficient. another unsuccessful patient with a closed - cell stent was the result of incorrect stent positioning, thus creating a misplacement of the stent. one failure with the closed - cell stent was the result from stent collapse (figure 1). two were complications from central migration of a stent during a placement that required an additional stent. a stent migration developed in two patients with closed - cell stents, one in the superior vena cava (svc) and one in the pulmonary artery. in one patient with stent migration to svc during procedure, the stent was successfully removed. the other stent had migrated into the right pulmonary artery after one day as post - pts, but there was failure of retrieval. in one patient with axillary vein rupture, balloon tamponade for 5 minutes was successfully performed. in another patient with innominate vein rupture, the insertion of one stent was sufficient to cover the entire lesion in each procedure. the mean follow - up period was 8.8 9.97 month (range, 1 - 75). follow - up fistulography was performed in 282 patients and only 21 patients had undergone clinical follow - up. there were three cases of technical failures, one case of death during follow - up, and 94 cases of no follow - up. for the open - cell stent group, the primary patency rate was 86.4%, 64.8%, 28.8%, and 9.3% at 3, 6, 12, and 24 months, respectively. for the closed - cell stent group, the primary patency rate was 69.1%, 38.7%, 16.0%, and 6.5% at 3, 6, 12, and 24 months, respectively. open - cell stents and closed - cell stents had mean patency rates of 10.9 0.80 months and 8.5 10.87 months, respectively (p = 0.002). the survival analysis of the primary patency rate for open - cell stent and closed - cell stent is show in figure 2. the mean patency rates in the open - cell stents group and closed - cell stents group are given in table 4 by lesion site, lesion type (stenosis or occlusion), and presence of thrombosis. the mean patency rate for subclavian vein stenosis or occlusion was 11.1 1.66 month in the open - cell stent group and 4.9 0.18 months in the closed - cell stent group (p <.001). the mean patency rate for innominate vein stenosis or occlusion was 11.1 0.92 months in the open - cell stent group and 10.1 1.50 months in the closed - cell stent group (p = 0.15). the mean patency rate for central vein stenosis was 10.5 0.87 months in the open - cell stent group and 8.0 1.11 months in the closed - cell stent group (p = 0.042). the mean patency rate for central vein occlusion was 11.9 1.59 months in the open - cell stent group and 8.9 1.92 months in the closed - cell stent group (p = 0.020). in the case of thrombosis, the mean patency rate was 11.4 2.02 months in the open - cell stent group and 10.6 6.53 months in the closed - cell stent group (p = 0.153). in cases without thrombosis, the mean patency rate was 10.9 0.85 months in the open - cell stent group and 8.2 0.99 months in the closed - cell stent group (p = 0.006). abbreviations : m, month ; v, vein values expressed as means sd. when analyzing across both open - cell stents group and closed - cell stents group, we found that a history of diabetes, hypertension, duration of chronic renal failure, and history of previous catheter insertion were significant in the open - cell stents group (table 1). considering the two groups collectively, the vessel most commonly treated was the innominate vein (n = 306), followed by the subclavian vein (n = 89), and jugular vein (n = 6). in the open cell - stent group, 205 innominate veins, 46 subclavian veins, and six jugular veins were involved, and in the closed - cell stent group, 101 innominate veins and 43 subclavian veins were involved. the author found 159 central vein stenoses, and 98 central vein occlusions in the open - cell stent group, and 78 central vein stenoses, and 66 central vein occlusions in the closed - cell stent group (table 3). there were 30 cases of thrombosis in the open - cell stent group, and 12 cases in the closed - cell stent group. one failure with an open - cell stent involved a successful stent placement, but coexistence of thrombosis in the graft site was not removed completely and the flow was insufficient. another unsuccessful patient with a closed - cell stent was the result of incorrect stent positioning, thus creating a misplacement of the stent. one failure with the closed - cell stent was the result from stent collapse (figure 1). two were complications from central migration of a stent during a placement that required an additional stent. a stent migration developed in two patients with closed - cell stents, one in the superior vena cava (svc) and one in the pulmonary artery. in one patient with stent migration to svc during procedure, the stent was successfully removed. the other stent had migrated into the right pulmonary artery after one day as post - pts, but there was failure of retrieval. in one patient with axillary vein rupture, balloon tamponade for 5 minutes was successfully performed. in another patient with innominate vein rupture, the insertion of one stent was sufficient to cover the entire lesion in each procedure. the mean follow - up period was 8.8 9.97 month (range, 1 - 75). follow - up fistulography was performed in 282 patients and only 21 patients had undergone clinical follow - up. there were three cases of technical failures, one case of death during follow - up, and 94 cases of no follow - up. for the open - cell stent group, the primary patency rate was 86.4%, 64.8%, 28.8%, and 9.3% at 3, 6, 12, and 24 months, respectively. for the closed - cell stent group, the primary patency rate was 69.1%, 38.7%, 16.0%, and 6.5% at 3, 6, 12, and 24 months, respectively. open - cell stents and closed - cell stents had mean patency rates of 10.9 0.80 months and 8.5 10.87 months, respectively (p = 0.002). the survival analysis of the primary patency rate for open - cell stent and closed - cell stent is show in figure 2. the mean patency rates in the open - cell stents group and closed - cell stents group are given in table 4 by lesion site, lesion type (stenosis or occlusion), and presence of thrombosis. the mean patency rate for subclavian vein stenosis or occlusion was 11.1 1.66 month in the open - cell stent group and 4.9 0.18 months in the closed - cell stent group (p <.001). the mean patency rate for innominate vein stenosis or occlusion was 11.1 0.92 months in the open - cell stent group and 10.1 1.50 months in the closed - cell stent group (p = 0.15). the mean patency rate for central vein stenosis was 10.5 0.87 months in the open - cell stent group and 8.0 1.11 months in the closed - cell stent group (p = 0.042). the mean patency rate for central vein occlusion was 11.9 1.59 months in the open - cell stent group and 8.9 1.92 months in the closed - cell stent group (p = 0.020). in the case of thrombosis, the mean patency rate was 11.4 2.02 months in the open - cell stent group and 10.6 6.53 months in the closed - cell stent group (p = 0.153). in cases without thrombosis, the mean patency rate was 10.9 0.85 months in the open - cell stent group and 8.2 0.99 months in the closed - cell stent group (p = 0.006). abbreviations : m, month ; v, vein values expressed as means sd. central vein stenosis or occlusion is a common complication of the chronic hemodialysis patient, resulting in considerable edema of the arm with vascular access that is unable to drain normally. that is why the percutaneous approach is preferable to the surgical approach (20). stents are thought to add a beneficial effect to angioplasty by limiting the elastic recoil present in compliant veins, excluding damaged and dissected intravascular tissues, and acting as an intravascular support to counteract extrinsic compression (12). this is especially relevant for the central venous lesion, described as having high elastic recoil and poor results with pta alone (12). it is natural to expect that reports concerning pta as the only management option would have lower patency rates. previous findings in the patency rates of central vein obstruction in pts vary widely from ours. we believe that the main reasons for this variation are the different pts protocols, types of stents, study populations, age of access, access thrombosis at the time of intervention, and veins treated (8, 10, 12, 21, 22). a stent can be classified as a closed - cell stent or an open - cell stent, depending on the density of struts (15). closed - cell stents are characterized by small free cell areas between struts, whereas open - cell stents have larger uncovered gaps (figure 3) (23). closed - cell stents with a small cell size have a dense, metallic mesh and therefore, may provide more effective plaque coverage and reduce the risk of particle embolization (16). however, closed - cell stents are known to be less flexible and more rigid and are more likely to be used in straight morphologies (16). in contrast, open - cell stents are flexible ; kinked lesions are ideally treated with these stents (16). new stents were designed to incorporate visibility, flexibility, and expandability, permitting the treatment of the most complex venous lesion through endovascular means. potential advantages of this approach include its less invasive nature, safety, ability to be done on an outpatient basis, better preservation of native veins, and, most important, its association with greater patient satisfaction and less discomfort (12). previous studies using closed - cell stents (wallstent, boston scientific, natick, ma) have failed to demonstrate improved survival or patency compared with angioplasty (7, 11, 12). reports concerning the use of the wallstent in central vein obstruction are common (13, 24, 25). with wallstents, primary patency ranged from 42% to 84% at 6 months, but was less than 31% at 12 months in four studies (8, 10 - 12), with haage. (13) demonstrating 56% primary patency at 12 months. unfortunately, no one has since reported results as successful as those that the haage group did. early experience with open - cell stents (zilver nitinol stent, cook, bloomington, in, usa) for central venous occlusion appears to indicate that they confer longer mid - term patency than historically observed results for central venous occlusion and central venous stenosis using wallstents (22). in a study conducted by vogel and parise (14), use of the smart stent demonstrated 67% primary patency for central venous stenosis at 12 months. in a study performed by rajan and saluja (22), use of the zilver nitinol stent (cook, bloomington, in, usa) demonstrated 66.7% primary patency for central venous stenosis at 6 and 12 months. there have been two reports comparing the closed - cell stent with open - cell stent (26, 27). the authors of those reports reported no significant difference between the patency of the wallstents and the nitinol - based memotherm or luminexx stent in their small groups (26, 27). we have reported our large group study in stent treatment of central vein stenosis or occlusion with open - cell stent or closed - cell stent. we found that the primary patency rate of open - cell stent was significantly higher than that of the closed - cell stent. the 6-month and 12-month primary patency rates with the open - cell stent were 64.8% and 28.8%, respectively, and primary patency rates with closed - cell stent were 38.7% and 16.0%, respectively. open - cell stents and closed - cell stents had mean patency rates of 10.9 0.80 months and 8.5 10.87 months, respectively (p = 0.002). the reported patency rate of 66.7% at 6 and 12 months following nitinol stent placement by rajan and saluja (22) might be the result of a small patient population (n = 6). in this study, the mean patency rate of the subclavian vein with open - cell stent was 11.1 1.66 months and the mean patency rate with closed - cell stent was 4.9 0.18 months. there is a significant difference in the subclavian vein stenosis or occlusions between the open - cell stent group and closed - cell stent group in this study (p < 0.001). our results might be related to characteristics of the open - cell stent, including flexibility, radial strength, and expansibility. the open - cell stent has physical properties that differ from those of the closed - cell stent. the closed - cell stent appears to have problems with its shortening and migrating during respiration (figure 4) (8, 10, 11, 13). the efficacy of stent deployment appears to vary by the vascular location of the stenotic lesion. recently, nitinol stents have been introduced and have several physical characteristics that may confer longer patency compared with wallstents (28). nitinol, an alloy of nickel and titanium, exists in two temperature - dependent forms, which are predetermined by adjusting the ratio of nickel and titanium and through high - temperature heating. when nitinol assumes its higher - temperature form, it expands to its predetermined size and becomes more rigid. nitinol is also superelastic in that it will deform its shape but return to its original configuration when an external force is applied and then removed (29 - 31). shape memory and superelasticity allow for an improved apposition of the stent along the vessel wall and maintenance of radial strength (figure 5). the wallstent is constructed of elgiloy, the free ends are sharp and capable of embedding into the vessel wall. eccentric loading of the wallstent such as that produced by a stenosis results in concentric narrowing beyond the point at which the load is applied, making it susceptible to reduced wall contact and decreased radial strength (32). poor or incomplete wall contact appears to be a risk factor for in - stent stenosis (33, 34), and decreased radial strength (29). in this study, there was a case of incomplete wall contact in the closed - cell stent group for stenosis at the left innominate vein (figure 6). closed - cell stent has also been observed to migrate and foreshorten in central venous segments (figure 4) (8, 10, 11, 13). in addition, two cases of central stent migration were observed in patients with closed - cell stent in this study. open - cell stents have become standard practice over closed - cell stents, mainly due to easier and more precise placement, non - shortening of the open - cell stents, and a longer vascular patency. the superelasticity and shape - memory characteristics of the nitinol stent improve flexibility, which also improve opposition to the vessel wall (figure 5). depending on the density of the bridges between the different rings, nitinol stents can be classified into stents with a closed - cell or an open - cell configuration. flexibility depends on the stent s ability to conform the vessel tortuosity in the deployed state. closed - cell stents are rigid, less flexible and may develop kinks and incomplete deployment in the tortuous vessel. conversely, stents with an open - cell configuration conform best to angulated vessels or tortuous anatomy. stents with a flexible and conformable open - cell configuration are preferred in vessels that are angulated or have a tortuous anatomy. patients in this study group did not experience any major morbidity or mortality, except for two cases of stent migration and minor complications. first, this study was retrospective and had mixed group patients among those with or without a history of hypertensio, diabetes mellitus, peripheral vascular disease, and use of tobacco, so their possible effects on patency rates could not be assessed. although a history of diabetes, hypertension, duration of chronic renal failure and history of previous catheter insertion is more common in the open - cell stents group, the open - cell stent is more effective for treatment of central vein stenosis or occlusion in hemodialysis patients. it is unknown what role concurrent stenosis along the access circuit may have on patency following intervention for central venous occlusion. in conclusion, the open - cell stent is effective for the treatment of central vein stenosis or occlusion in hemodialysis patients who have incomplete pta results. these results suggest the use of open - cell stent for the treatment of central vein stenosis or occlusion in hemodialysis patients. | backgroundcentral vein stenosis or occlusion is a common complication that can lead to significant morbidity and dysfunction of access in the hemodialysis patient. more lesions can develop over time, and preserving access becomes a challenge as life expectancy of the hemodialysis patient increases.objectivesthe goal was to compare long - term results and determine the outcomes of open - cell stent versus closed - cell stent for central vein stenosis or occlusion in hemodialysis patients.patients and methodsfrom 1997 to 2015, in 401 hemodialysis patients, stent placement for central vein stenosis or occlusion was performed if balloon angioplasty was unsatisfactory, due to elastic recoil or occurrence of restenosis within 3 months. when thrombus was present, primary stenting was performed. a total of 257 open - cell stents and 144 closed - cell stents were used. angiographic findings including lesion site, central vein stenosis or occlusion, and presence of thrombosis and complication were evaluated. primary patency rate and mean patency rate of the stent were compared between two stent groups by kaplan - meier survival analysis.resultsfor the open - cell stent group, 159 patients were diagnosed as central vein stenosis and 98 were occlusion. for the closed - cell stent group, 78 were stenosis and 66 were occlusion. there were two complications for central migration and two for procedure - related vein rupture. open - cell stents and closed - cell stents had mean patency rates of 10.9 0.80 months and 8.5 10.87 months, respectively (p = 0.002).conclusionthe open - cell stent is effective and its performance is higher than that obtained with the closed - cell stent for treating central vein stenosis or occlusion in hemodialysis patients. |
hepatocellular carcinoma (hcc) is the fifth most common cancer worldwide with increasing annual incidence worldwide. although the incidence of hcc increases in recent years due to hepatitis c virus (hcv) infection, alcohol - related cirrhosis and possibly nonalcoholic fatty liver disease in western countries, more than half of the new cases still occur in china which is an area of high hepatitis b virus (hbv) infection. in spite of many other patterns of treatment, such as radiofrequency, transarterial therapy, chemotherapy or radiotherapy, and so on, are frequently recommended and have been used to treat the hcc patients, surgery is still the main first - treatment to hcc patients in clinic. clinical staging systems are important which are not only able to provide evidence for disease assessment, but also help to make therapeutic decisions. staging systems for most solid cancers are available and consistently used in clinic, but the system for hcc is more difficult and remains unknown because there are much biological variability related to different etiologies and incomplete understanding of its natural history. currently, eight hcc staging systems used in clinic mainly include two tumor - node - metastasis classification 6 and 7 (tnm), the okuda staging, cancer of the liver italian program score (clip), the barcelona clinic liver cancer staging system (bclc), the model for the chinese university prognostic index grade (cupi), the japan integrated staging score (jis) and tokyo score. nevertheless, clinical trials and comparative studies revealed that no appropriate staging system could be applied in all the population due to the different etiologies of hcc, clinical performance, and treatments. among these staging systems, bclc and clip staging systems had been proved more effective than others in western countries where the main etiologies are hcv infection and alcohol abuse, and for asian - pacific region, tnm and jis staging systems seemed to be more applicable. recently, cupi system, the biggest clinical research program focusing chinese populations, was mainly applied for the hcc patients in late stage and had the complicated calculation method, which might limit its clinical application. considering the clinic treatment, hepatic resection is the primary treatment method for patients with resectable hcc, who have adequate liver function. in this study, we included 743 hbv - related chinese hcc patients who received surgery first and evaluated the predictive values of eight different staging systems, which were commonly used in the clinic. in this study, 743 patients with hcc underwent surgery were recruited from january 1999 to december 2010 at the hepatobiliary surgery center, cancer hospital, chinese academy of medical sciences, beijing, china. characteristics and medical information, including age, sex, etiology of chronic liver disease, pathology results, serum biochemistries, and treatment were obtained from patients medical records. overall survival time of patients was measured from the date of surgery to the date of last follow - up or death. whether and when a patient had died was obtained from inpatient and outpatient records, patients families or local public security census register office through follow - up telephone calls. the last date of follow - up was december 31, 2011, and no patients were lost to follow - up. the median follow - up time was 62 months. written informed consent was obtained from all patients and this study was approved by the institutional review board of the chinese academy of medical sciences cancer institute. distributions of selected characteristics of 743 patients with hcc in this study hcc : hepatocellular carcinoma ; afp : alpha - fetoprotein ; pei : percutaneous ethanol injection ; rfa : radiofrequency ablation. the etiology of hcc of all the patients was hbv infection, whose serological detection of hepatitis b surface antigen was positive. during the surgery process, four types of surgery methods, curative hepatectomy, radiofrequency ablation (rfa), percutaneous ethanol injection (pei), palliative hepatectomy were given to the patients. curative hepatectomy and rfa were used to remove or ablate all lesions with a tumor - free margin ; palliative hepatectomy and pei were applied to stanch the blood by tumor rupture or reduce tumor burden. other adjuvant therapies including transarterial therapy, chemotherapy / target therapy / placebo therapy, or radiotherapy were given to selected patients with preserved liver functions and distant tumor metastasis after surgery. all the patients were retrospectively assigned to different stages according to the criteria of classification of eight different staging systems, respectively as followed : (1) tnm classification system, (2) the okuda staging, (3) clip, (4) the bclc, (5) the model for the cupi, (6) the jis (7) and tokyo score. all the classifications were stringently based on the patients clinical information. for each of the selected staging system, we performed cox proportional hazards regression adjusted by age and sex to evaluate the association between patients in various stages and their overall survival in different staging systems, respectively. meier survival estimates were plotted, and p values were assessed using log - rank tests. in order to neutralize the potential bias in comparing prognostic scores with different numbers of stages, akaike information criterion (aic) was calculated by the results of cox 's regression. the aic analysis represents an overall assessment of a certain staging system and is the most important statistic method for the comparison across different staging systems. the lower aic values, the more accurate and informative explained by a certain stage. in this study, 743 patients with hcc underwent surgery were recruited from january 1999 to december 2010 at the hepatobiliary surgery center, cancer hospital, chinese academy of medical sciences, beijing, china. characteristics and medical information, including age, sex, etiology of chronic liver disease, pathology results, serum biochemistries, and treatment were obtained from patients medical records. overall survival time of patients was measured from the date of surgery to the date of last follow - up or death. whether and when a patient had died was obtained from inpatient and outpatient records, patients families or local public security census register office through follow - up telephone calls. the last date of follow - up was december 31, 2011, and no patients were lost to follow - up. the median follow - up time was 62 months. written informed consent was obtained from all patients and this study was approved by the institutional review board of the chinese academy of medical sciences cancer institute. distributions of selected characteristics of 743 patients with hcc in this study hcc : hepatocellular carcinoma ; afp : alpha - fetoprotein ; pei : percutaneous ethanol injection ; rfa : radiofrequency ablation. the etiology of hcc of all the patients was hbv infection, whose serological detection of hepatitis b surface antigen was positive. during the surgery process, four types of surgery methods, curative hepatectomy, radiofrequency ablation (rfa), percutaneous ethanol injection (pei), palliative hepatectomy were given to the patients. curative hepatectomy and rfa were used to remove or ablate all lesions with a tumor - free margin ; palliative hepatectomy and pei were applied to stanch the blood by tumor rupture or reduce tumor burden. other adjuvant therapies including transarterial therapy, chemotherapy / target therapy / placebo therapy, or radiotherapy were given to selected patients with preserved liver functions and distant tumor metastasis after surgery. all the patients were retrospectively assigned to different stages according to the criteria of classification of eight different staging systems, respectively as followed : (1) tnm classification system, (2) the okuda staging, (3) clip, (4) the bclc, (5) the model for the cupi, (6) the jis (7) and tokyo score. for each of the selected staging system, we performed cox proportional hazards regression adjusted by age and sex to evaluate the association between patients in various stages and their overall survival in different staging systems, respectively. meier survival estimates were plotted, and p values were assessed using log - rank tests. in order to neutralize the potential bias in comparing prognostic scores with different numbers of stages, akaike information criterion (aic) was calculated by the results of cox 's regression. the aic analysis represents an overall assessment of a certain staging system and is the most important statistic method for the comparison across different staging systems. the lower aic values, the more accurate and informative explained by a certain stage. the median age of all the patients was 55 years old (range = 1985) and the majority of them were male (n = 643, 86.5%). all the patients were receiving surgery as their first clinical treatment : 700 patients (94.2%) received curative hepatectomy, 19 patients (2.6%) received rfa, 15 patients (2.0%) received pei and 9 patients (1.2%) received palliative hepatectomy, respectively. considering the treatment after the surgery, 348 patients (46.8%) received adjuvant therapies including transarterial therapy (n = 331), chemotherapy / target therapy / placebo (n = 62) or radiotherapy (n = 17). the median size of the tumor is 4.0 cm, and 614 patients (82.6%) have a single tumor. vascular involvement was identified in 70 patients (9.4%) by pathology while major vascular invasion was detected in 19 patients (2.6%) by imaging studies. the median afp value of serum biochemistry was 30.83 g / ml. by the last date of follow - up, 253 (34.1%) patients were dead and 490 (65.9%) patients still survived. the overall 1-, 3-, 5-year survival rates and median survival were 91.5%, 70.3%, 55.3% and 72 months. eight staging systems were used to stratify the hcc patients into different stages, respectively. the comparisons of survival distributions according to different stages are illustrated in figure 1a (bclc), figure 1b (tnm 7), figure 1c (tnm 6), figure 1d (jis), figure 1e (tokyo), figure 1f (clip), figure 1 g (cupi), figure 1h (okuda), respectively. significant survival difference was found across all groups of these staging systems (p < 0.05) except for the comparison between tnm 7 stage iv versus iii (p = 0.1574), tnm 7 stage iv versus iii (p = 0.5366), tokyo score 1 versus 0 (p = 0.3930), tokyo score 4 versus 3 (p = 0.5691), tokyo score 5 versus 4 (p = 0.0823), clip score 3 + 4 versus 2 (p = 0.9283), okuda stage i versus stage 0 (p = 0.1107), okuda stage ii versus stage i (p = 0.7077) [table 2 ]. meier curves by different stages in eight staging systems. (a) barcelona clinic liver cancer, (b) tumor - node - metastasis (tnm) 7, (c) tnm 6, (d) japan integrated staging, (e) tokyo, (f) cancer of the liver italian program, (g) chinese university prognostic index, (h) okuda. associations of different staging systems with overall survival of hcc patients mst : median survival time. hr (95% ci) and p were calculated using cox proportional hazards regression adjusted by age and sex and the lower stage or score was as the reference when the risk progressed from lower stage or score to the higher one. aic : akaike information criterion was calculated using the additive model of each staging system ; hcc : hepatocellular carcinoma ; hr : hazard ratio ; ci : confidence interval ; bclc : barcelona clinic liver cancer ; tnm : tumor - node - metastasis ; jis : japan integrated staging ; clip : cancer of the liver italian program ; cupi : chinese university prognostic index. using additive model, all the staging systems except okuda staging system stratified overall survival rates of hcc patients and furthermore, we measured the aic values from cox 's regression analysis to compare the major hcc staging systems [table 2 ]. blcl staging systems showed the lowest aic values (2896.577), followed by tnm 7 (aic = 2899.980), tnm 6 (aic = 2902.17), jis (aic = 2918.085), tokyo (aic = 2938.822), clip (aic = 2941.950), cupi (aic = 2962.027), and okuda (aic = 2979.389). the median age of all the patients was 55 years old (range = 1985) and the majority of them were male (n = 643, 86.5%). all the patients were receiving surgery as their first clinical treatment : 700 patients (94.2%) received curative hepatectomy, 19 patients (2.6%) received rfa, 15 patients (2.0%) received pei and 9 patients (1.2%) received palliative hepatectomy, respectively. considering the treatment after the surgery, 348 patients (46.8%) received adjuvant therapies including transarterial therapy (n = 331), chemotherapy / target therapy / placebo (n = 62) or radiotherapy (n = 17). the median size of the tumor is 4.0 cm, and 614 patients (82.6%) have a single tumor. vascular involvement was identified in 70 patients (9.4%) by pathology while major vascular invasion was detected in 19 patients (2.6%) by imaging studies. the median afp value of serum biochemistry was 30.83 g / ml. by the last date of follow - up, 253 (34.1%) patients were dead and 490 (65.9%) patients still survived. the overall 1-, 3-, 5-year survival rates and median survival were 91.5%, 70.3%, 55.3% and 72 months. eight staging systems were used to stratify the hcc patients into different stages, respectively. the comparisons of survival distributions according to different stages are illustrated in figure 1a (bclc), figure 1b (tnm 7), figure 1c (tnm 6), figure 1d (jis), figure 1e (tokyo), figure 1f (clip), figure 1 g (cupi), figure 1h (okuda), respectively. significant survival difference was found across all groups of these staging systems (p < 0.05) except for the comparison between tnm 7 stage iv versus iii (p = 0.1574), tnm 7 stage iv versus iii (p = 0.5366), tokyo score 1 versus 0 (p = 0.3930), tokyo score 4 versus 3 (p = 0.5691), tokyo score 5 versus 4 (p = 0.0823), clip score 3 + 4 versus 2 (p = 0.9283), okuda stage i versus stage 0 (p = 0.1107), okuda stage ii versus stage i (p = 0.7077) [table 2 ]. (a) barcelona clinic liver cancer, (b) tumor - node - metastasis (tnm) 7, (c) tnm 6, (d) japan integrated staging, (e) tokyo, (f) cancer of the liver italian program, (g) chinese university prognostic index, (h) okuda. associations of different staging systems with overall survival of hcc patients mst : median survival time. hr (95% ci) and p were calculated using cox proportional hazards regression adjusted by age and sex and the lower stage or score was as the reference when the risk progressed from lower stage or score to the higher one. aic : akaike information criterion was calculated using the additive model of each staging system ; hcc : hepatocellular carcinoma ; hr : hazard ratio ; ci : confidence interval ; bclc : barcelona clinic liver cancer ; tnm : tumor - node - metastasis ; jis : japan integrated staging ; clip : cancer of the liver italian program ; cupi : chinese university prognostic index. using additive model, all the staging systems except okuda staging system stratified overall survival rates of hcc patients and furthermore, we measured the aic values from cox 's regression analysis to compare the major hcc staging systems [table 2 ]. blcl staging systems showed the lowest aic values (2896.577), followed by tnm 7 (aic = 2899.980), tnm 6 (aic = 2902.17), jis (aic = 2918.085), tokyo (aic = 2938.822), clip (aic = 2941.950), cupi (aic = 2962.027), and okuda (aic = 2979.389). a superior liver cancer staging system was still needed to divide patients clearly into different groups based on their risk factors, objective, quantitative data, and simple calculation methods. therefore, clinical doctors can easily make a decision on further treatment or recruitment of clinical research based on these factors and predict patients prognosis. the discrepancies of hcc staging systems among studies might be attributed to several factors that potentially influenced results, including tumor related variables, etiologies, first - line treatment, different populations, samples sizes, and so on. it has been demonstrated that hbv - related hcc and hcv - related hcc have different mechanisms in hepatocarcinogenesis and clinical manifestations and the relation between the etiologies of hcc and its prognosis remains controversial. the aim of this study is to find a superior staging system for predicting survival of patients with hcc after surgery for hbv - related chinese populations. two strengths of our study are that all the patients were hbv - infected and received the same treatment model of surgery as their first - line treatment. we compared eight different staging systems for 743 chinese hcc patients who are all hbv infection. all staging systems except okuda staging system stratified overall survival rates of hcc patients and bclc staging system showed the best prognostic ability for cancer staging in terms of long - term survival outcome. the bclc staging classification has been widely accepted for stratification of hcc patients in clinical practice guidelines, as it not only incorporates child - pugh stages, presence of portal hypertension, tumor morphology, and performance status as variables but has also been validated by renowned scientific societies as a useful tool able to differentiate the prognosis of hcc patients. the prominent character of bclc staging is that it includes evidence - based clinical treatment, and its surgical indications have also been recognized as a guideline for surgical treatment of hcc in a number of countries. bclc has been externally validated more effective than others in western countries where main etiologies are hcv infection and alcohol abuse and for asia area, some studies also proved it be a superior staging system. recently, a study of 1717 hcc candidates (72.1% for hbv related - hcc) showed bclc was the best prognostic model in a large - scale korean cohort. in our study, bclc proved to be the best staging system for hbv - related hcc (aic = 2896.58) as well. although some studies showed that bclc staging system performed poorly in predicting the survival of patients with early hcc after liver resection, our study demonstrated that bclc staging has a superior discriminable ability for early stage hcc between stage 0 and stage a (p = 0.0195). six other staging systems all have the discriminatory ability for death in long - term survival prediction after surgery. tnm staging system (american joint committee on cancer staging [ajcc ]) for hcc has been modified several times to the recent seventh edition in 2009. the major change between the 6 and the 7 ajcc staging system is that the new system imposes heavier prognostic weight on major vascular invasion as a potential predictive factor for poor prognosis. our results showed that the prognostic performance of tnm 7 and tnm 6 staging system are the second and third best staging system associated with overall survival of hcc patients among all staging systems, respectively. this is consistent with the traditional view that tnm staging is suitable for asian - pacific population who received resection. however, the limitation of tnm staging was without the consideration of the category of liver function to classify the patients, which is well accepted as a prominent factor for hcc overall survival and more and more scholars highlighted the importance of liver function factor in hcc patients staging categories. however, all the patients included in our study had relatively well - preserved liver function and could receive surgery as their first clinical treatments, more than 90% of patients under the same curative hepatectomy, so the impact of cirrhosis factor on survival could be minimized. therefore, it is reasonable two tnm staging systems have better prognostic performances over others. the jis score is consisted of the japanese tnm staging and the child - pugh sore and appears to be one of the most promising classification systems in the asia - pacific region. it has been noted that the jis system may be limited in its ability to stratify patients with advanced scores because it uniformly assigns tumor stage and live function. although jis score did not show superiority in prediction performance over bclc staging system in our study, it remains the forth suitable staging system and all the four stages could be clearly stratified (all p < 0.05). tokyo score was established from the study of consecutive patients with hcc treated by percutaneous ablation in 2005. the advantage of this staging is its simplicity only including albumin, bilirubin, tumor size and tumor number as the variants. the original aim developing this staging system was to evaluate the prognosis of patients at early - stage who receive radical treatment. our study also showed that tokyo staging had poor stratification ability for late - stage (sore 3 versus 4 ; sore 4 versus 5), which was also consistent with its disadvantage in late - stage candidates. clip system was established from the study of 435 patients with hcc from 16 italian institutions. it was widely proven to be a better prognostic model for late - stage hcc population, and a good staging system in some cohort studies from europe populations, japanese, populations in middle - east regions, and the region of taiwan of china, and so on. however, there are still some limitations of clip staging : firstly, the definition of tumor morphology in clip staging category is relatively too broad to distinguish staging subgroups correctly due to the development of imaging technology in recent years ; secondly, all studies to date showed a high proportion of patients were categorized as clip score 02, which means its low discriminatory ability for late - stage candidates with clip scores of 46. the results of our study were consistent with previous literature results, only 19 (2.6%) hcc patients were classified into score 34 group and did not show discriminatory ability for late - stage candidates with the p value of score 3 + 4 versus score 2 being 0.9283. the cupi score was developed by the chinese university in hong kong in 2002 and the only system used widely for chinese hcc patients with hbv infection. however, some studies in chinese populations showed that cupi had limited efficacy in predicting survival of hcc patients undergoing surgical resection. cupi score was based on the fifth edition of the tnm, but the tnm 6 and tnm 7 was broadly reported superior in discriminating survival among patients in different stages, so it needs to be further modified. the cupi staging calculation seems relatively complicated, and it contains only three risk subgroups, and both of them limit its clinical use. in our study, only two cupi stages, low risk and intermediate risk, were included and patients in late - stage using tnm or bclc staging systems could not be precisely classified to high - risk group in cupi system and this relatively decreased the analysis power of our study. furthermore, only a small proportion (10.4%) of early - stage hcc patients received surgery original enrollment of cupi study, so its prognostic ability for early hcc was restricted. the okuda classification was the first staging system combining tumor size and liver function by japanese study in 1999. however, as it contains fewer tumor factors and high threshold of bilirubin level, this staging system has been gradually losing favor with the emergency of newer staging systems. our study has proved that okuda staging was the only staging system which had no significant prognostic ability in determining overall survival, which was in accordance with previous studies. first, all the hcc patients included in this study were chinese han populations with hbv infection that exclude the effect of other etiologies or population heterogeneities on the survival of patients. a homogeneous group of patients may enhance our ability to find a suitable staging system. second, all the patients received surgical resection as their first clinical treatment which not only provided a correct pathology diagnosis for all the patients but also could decrease the effect of different treatments to the overall survival of hcc patients. third, we collected more than 20 variables which might associate with overall survival of hcc patients, which help us comprehensively compared eight different staging systems based on the same populations. fourth, reviewing previous literature, sample volume of 743 cases for homogenous hbv - related hcc ethnic chinese population is relatively large. firstly, the proportion of patients in late - stage was relative small which could decrease the analysis power. however, all the patients had the same etiology, and first clinical treatment could help us to identify a suitable staging system in a homogeneous patients. secondly, this is a single - center experience, and the study design is retrospective, it remains to be warranted to validate the prognostic value of this staging system in other well - designed cohorts. in all, we identify the bclc staging system is a better staging model for hbv infection patients with hcc in chinese population among the eight currently used staging systems. these identifications afford a large group of chinese hcc patients with hbv infection and could be helpful to design a new staging system for a certain population. | background : hepatocellular carcinoma (hcc) is a common cancer in china, an area of high hepatitis b virus (hbv) infection. although several staging systems are available, there is no consensus on the best classification to use because multiple factors, such as etiology, clinical treatment and populations could affect the survival of hcc patients.methods:this study analyzed 743 hbv - related chinese hcc patients who received surgery first and evaluated the predictive values of eight different commonly used staging systems in the clinic.results:the overall 1-, 3-, 5-year survival rates and a median survival were 91.5%, 70.3%, 55.3% and 72 months respectively. barcelona clinic liver cancer (bclc) staging systems had the best stratification ability and showed the lowest akaike information criterion (aic) values (2896.577), followed by tumor - node - metastasis 7th (tnm 7th) (aic = 2899.980), tnm 6th (aic = 2902.17), japan integrated staging score (aic = 2918.085), tokyo (aic = 2938.822), cancer of the liver italian program score (aic = 2941.950), chinese university prognostic index grade (aic = 2962.027), and okuda (aic = 2979.389).conclusions : bclc staging system is a better staging model for hbv infection patients with hcc in chinese population among the eight currently used staging systems. these identifications afford a large group of chinese hcc patients with hbv infection and could be helpful to design a new staging system for a certain population. |
infertility is a major health challenge that has caused 15% of couples around the world (1) and 22% of couples in iran (2) to face mental, social (3), and financial consequences ; therefore, it is considered a general health issue. the desire to have children is one of the basic human instincts ; because in most of the couples fertility is an important matter to complete their male or female character and identification, and their final goal of life. but in societies like iran where cultural norms value mothers more than women, the consequences (4, 5) would be intensified and could lead to social and mental problems (6). although infertility as a source of stress could threaten the mental health of infertile people (7) but the magnitude of its effects depends on personal coping behaviors (8). coping is the cognitive and behavioral efforts to control and manage stressful events of life (9) and could moderate the negative effects of the stressful situations most of the times. studies have shown that coping strategies toward infertility is associated with the level of stress (8, 10), psychological development of infertile men (11), depression, and anxiety (12) and interventional programs in order to cope with the crisis of infertility could enhance the quality of life (13). but to manage the agitations and stresses caused by infertility and plan for promoting coping strategies in infertile couples, identifying predictor factors is necessary. the couples ' beliefs and attitude toward infertility, which are based on social and cultural factors and their inner desires, could affect the couple 's ability to deal with the infertility crisis. but these valuations and their effect on individual 's adaptation ability toward infertility issue would grow in the cultural, social (14) and religious (15) context of each individual that should be investigated. therefore, the aim of this study was to assess the relationship between the attitude toward infertility and coping strategies in couples undergoing assisted reproductive treatments. this was a cross sectional study conducted on 133 iranian couples who referred for assisted reproductive treatments in the fertility and infertility center of isfahan from october 2013 to march 2014. the exclusion criteria were using donated egg or embryo, having any biological or adopted child, and having any known mental diseases based on their medical recodes. informed consent was received from all the participants. at the beginning, demographic data including age, level of education, financial situation according to their own opinion, and employment status was gathered. social status of couples was evaluated based on their employment status and level of education. the cause of infertility was identified by reviewing the couple 's file and was categorized as female, male, or unknown. data gathering tools were the attitude toward infertility questionnaire and the r - cope questionnaire. the attitude toward infertility questionnaire was a researcher made questionnaire using likert scale (15) including 10 questions that was developed by reviewing scientific references and its content validity was confirmed by 5 experienced specialists (one psychometric expert and four psychologists). the questionnaire 's reliability was confirmed with a reproducibility index of 0.8 by conducting a pilot study on 15 eligible infertile couples in two stages with a one week interval. the r - cope questionnaire with 19 terms is developed based on literature review and available questionnaires (16). this questionnaire has been set on likert scale (14) from rarely (1) to mostly (4). after the completion of questionnaires by participants, the internal validity of the questionnaire was calculated to be 0.78 by omitting the questions that would reduce cronbach 's to less than 0.75. the final questionnaire included 20 questions to evaluate coping methods in 5 domains of active confronting, self - blame, self - focused rumination, avoidance, and goal replacement. the attitude toward infertility questionnaire and r - copr questionnaire were filled by each spouse separately. data was analyzed using spss 16 and paired - samples t test and multiple regression model. the comparison of mean of attitude toward infertility and coping strategies is presented in table 1. there was no significant difference between the mean score of attitude toward infertility and coping strategies between couples. comparison of coping strategies and infertility attitude between women and men no significant differences were seen assessing the relationship between the attitude toward infertility and coping strategies, results showed that in both men and women, independent from demographic information and cause of infertility, use of self - blame and self - focused rumination coping strategies have an inverse and significantly meaningful correlation with the attitude toward infertility (tables 2 and 3). also, the use of self - blame strategy had a positive and significant correlation with female infertility and a negative and significant correlation with male infertility. also, there was no significant relationship between the use of coping strategies and any of the demographic information (table 2). relationship between coping strategies and attitude toward infertility among women relationship between coping strategies and attitude toward infertility among men the use of coping strategies in men was not related with the cause of infertility but using active confronting strategy in men had a positive and significant correlation with level of education. this study assessed the method of coping with infertility in couples undergoing assisted reproductive treatments and its relation with their attitude toward infertility, independent from social and financial factors. descriptive data of the study showed that couples undergoing assisted reproductive treatments use avoidance strategy less than other strategies in facing infertility. also, comparing the use of strategies between men and women, results showed that infertile couples used similar strategies. unlike the results of the present study, peterson. reported that before couples started assisted reproductive treatments, men used planful problem solving strategy whereas women mostly sought social support and used confronting coping and avoidance strategies (17). this difference could be due to the cultural context of iranian society. most of the iranian infertile couples would rather undergo treatment without informing others about their plan. especially since in iran like many other regional countries fertility is usually attributed to women (18, 19), revealing the need for assisted reproductive treatments would increase anxiety mostly in women and would cause women to be reluctant about sharing their feelings and to seek for social support. also starting assisted reproductive treatment means that the couple has reached a mutual decision ; therefore, it is expected that they do not use avoidance strategy. anxiety after starting assisted reproductive treatment (20) could negate men 's efforts in finding an appropriate solution to resolve conflicts caused by the situation and would appear as self - focused rumination. also, lack of information and skills about assisted reproductive treatments (21) could lead to obsessions. although women have also used the opportunities in their life for changing their goals to moderate the stress caused by infertility, having more opportunities to enter into different social and financial fields has made it easier for men to replace their goals. it could also be possible that gender roles for women were more important than social roles because they tend to have children more than men (22). results showed that using some of the coping strategies in infertile couples is related to their attitude toward infertility. based on the results, negative attitude toward infertility in both men and women is associated with more self - blame and self - focused rumination. furthermore, results showed that female infertility, independent from the attitude toward infertility, has an adverse effect on coping strategies in women ; it was observed that women with female infertility used self - blame strategy more than others whereas men with male infertility used this maladaptive method less. to confirm this matter, a study reported that the spouses who were recognized with infertility used maladaptive methods more than others (17). another study in iran showed that women who have female infertility experience more depression and anxiety during assisted reproductive treatments than other women (23) which could lead to negative coping methods such as self - blame. while coping strategies in women were related to the cause of infertility in men, mostly they were related with their attitude toward infertility but not its cause. lack of relation between the attitude toward infertility and the cause of infertility in men could mean that men 's coping methods and attitude toward infertility are mostly affected by factors other than those related to infertility. studies have also shown that when facing infertility, men tend to pay less attention to infertility issues and use distancing strategy (17). these results show that coping strategies of iranian women are more influenced by interpersonal factors such as the attitude toward infertility rather than financial and social status. the effect of social aspects of infertility and the need to become a parent have been reported before (22). what makes the cause of infertility an important factor for leading women toward maladaptive strategies such as self - blame could be the cultural context. in societies like iran where fertility is an important index to evaluate the individuals in terms of their gender roles, infertile women are under more social pressures (24). in a study conducted in pakistan, it has been reported that one third of infertile women blame themselves for not being able to make their husbands happy. based on the results conducted in pakistan, 57% of women believed that women 's infertility is a compelling reason for men to marry again (25). generally, individual 's attitude toward infertility is related to the society 's attitude toward gender roles and the importance of fertility and it would grow in the society 's cultural context. however, this study was done among infertile couples who decided to use assisted reproductive treatment and stress of treatment could affect their attitude toward infertility. the present study showed that negative attitude toward infertility is associated with more use of maladaptive coping strategies and the attitude toward infertility in women is affected by the cause of infertility. therefore, besides learning necessary skills for using appropriate strategies to moderate infertility crisis, it is necessary to focus on the strengthening programs for coping with infertility, especially in women in social contexts which shape the attitude of people toward the aim of life and infertility. | background : using appropriate coping strategies has a positive influence on moderating mental pressures caused by infertility and the stress during treatment. using these strategies needs personal skills and they could be influenced by individual 's inner psychological and environmental factors. the aim of this study was to assess the relationship between the attitude toward infertility and coping strategies considering the couple 's social and financial situation.methods:this was a cross sectional study conducted on 133 volunteered couples undergoing assisted reproductive treatment. coping strategies and the attitude toward infertility were assessed using a self - report questionnaire. higher scores of attitude indicated positive attitudes. data was analyzed using paired - samples t test and multiple regression model.results:independent from demographic information and causes of infertility, using self - blame and self - focused rumination coping strategies were negatively related to attitude toward infertility in both men and women (p<0.05). also, using self - blame coping strategy had a positive correlation with female infertility and negative correlation with male infertility.conclusion:regardless of the economic and social conditions, in infertile couples, downward trend in attitude toward infertility is mostly associated with the use of maladaptive coping strategies. |
there are few studies that describe neuroimaging [computed tomography (ct) and magnetic resonance imaging (mri) ] and electroencephalogram (eeg) data in children who present with new - onset seizures. the eeg is recommended as a part of the neurodiagnostic evaluation of the child with an apparent first unprovoked seizure. the role of neuroimaging in children presenting with new - onset afebrile seizures / unprovoked seizure is not well defined. insufficient evidence is available to make a standard recommendation or guideline for the use of routine neuroimaging in children with first unprovoked seizure. in contrast, guidelines for obtaining neuroimaging in adult patients presenting with seizure have been published. in a few studies that have reviewed the yield of neuroimaging in children with unprovoked seizure, the prevalence of abnormalities ranged from 0% to 21%.[57 ] although there is ample investigation and data concerning initial management, treatment approaches, and outcomes in children with simple febrile seizures, there is somewhat less well - developed data on complex febrile seizures (cfs). the patients attending the emergency, in - patient and out - patient departments of advanced paediatrics division of sher - i - kashmir institute of medical sciences from november 2006 to november 2008, were enrolled for the study as per the criteria given. it was a prospective, stratified - randomized cohort study conducted on children in the age group of 6 months to 14 years having first - onset unprovoked seizures and cfs. children were excluded from the study if the seizure resulted from an acute situational etiology such as toxin, infection, or trauma. they were also excluded if they had a chronic neurologic illness limiting their activities of daily living, such as cerebral palsy, mental retardation, and pervasive development disorders, or had other abnormalities on neurologic examination or had simple febrile seizure. a detailed clinical and developmental history was taken and physical and neurological examination was carried out. blood samples of all subjects were drawn on admission and routine laboratory studies were performed. complete blood counts, blood sugar, serum na, k, calcium were analyzed in order to exclude possible metabolic disorder, and to identify a predominant seizure type and potential epilepsy syndrome. an eeg was performed in all the subjects in the study, using 18-channel eeg machine (model ee 18) from recorder and medicare system. the eeg was analyzed by a clinical neurologist from the department of neurology, skims, srinagar. computed tomography (ct) scan of head was performed in all the subjects on spiral ct (somatic - emotion from siemens). cranial mri was performed on patients who had focal findings in their eegs and in those where ct findings needed further characterization. abnormal cranial ct was categorized into volumetric reduction of the cerebral hemispheres, focal hypodense lesions, white matter hypodensity and lissencephaly / polymicrogyria. likewise, the abnormal mri was classified into cortical lesions, white - matter lesions, encephalomalacia, enlarged lateral ventricles and volume loss, and miscellaneous group. the proportional differences were measured by chi - square analysis and fisher 's exact test. partial seizures were observed in 86/276 patients, generalized seizures in 116/276 patients, cfs in 64/276, and undetermined seizures in 10/276 [tables 1a, 1b, table 2 ]. type of seizure disorders in children type of seizure disorders in children type of seizure disorders as per gender of children the sample of patients constituted predominantly male in all seizures 162/276 (58.7%) ; 114/276 (41.3%) were female. this disorder was present in 72/162 (58.7%) of males and 44/114 (38.6%) of females [tables 2 and 3 ]. type of seizure disorders as per age of children patients were divided into two groups on the basis of age. group one was constituted by children aged 6 months to 6 years and included 100/276 (36.2%) patients. group two was constituted by children > 6 years to 14 years old and included 176/276 (63.8%) patients. in the age group of 6 months to 6 years, 55/100 (55%) had cfs and 32/100 (32.0%) had generalized seizures. among children > 6 years to 14 years old, partial seizure was seen in 78/176 (44.3%), generalized seizure in 84/176 (47.7%) and only 9/176 (5.1%) had cfs. the age distribution between the seizure types was statistically significant, with predominance of cfs in the age group of 6 months to 6 years to 14 years old [tables 2 and 3 ]. eeg abnormalities were significantly low (p 6 years to 14 years old and included 176/276 (63.8%) patients. in the age group of 6 months to 6 years, 55/100 (55%) had cfs and 32/100 (32.0%) had generalized seizures. among children > 6 years to 14 years old, partial seizure was seen in 78/176 (44.3%), generalized seizure in 84/176 (47.7%) and only 9/176 (5.1%) had cfs. the age distribution between the seizure types was statistically significant, with predominance of cfs in the age group of 6 months to 6 years to 14 years old [tables 2 and 3 ].. 10/64 (15.6%) patients with cfs had such abnormality [table 4 ]. electro encephalographic findings in studied subjects sharp and spike waves, alone or the combination were common eeg findings. in partial seizures, sharp and spike waves were seen in 24/86 (27.9%) patients ; sharp waves alone were seen in 19.8% patients and spike waves in 16.3% patients. asymmetry with sharp waves and spikes was seen in 12.8% patients. in generalized seizures, sharp and spike waves were common, with 24.1% patients having them. sharp waves alone were seen in 17.0%, and spikes alone were seen in 14.0% of patients. in cfs, asymmetry with sharp waves and spikes was the most common abnormality, seen in 10.9% of patients. in undetermined seizures, the asymmetry wave pattern was seen in 20% of patients, which is statistically significant in our study (p < 0.000) [table 5 ]. electro encephalographic findings in studied subjects ct abnormalities were observed in 27/276 (9.8%) patients. in partial seizure, 73/86 (84.9%) patients had normal imaging and 15.1% had abnormal imaging with volumetric reduction of cerebral hemisphere consistent with cerebral atrophy in 4/86 (4.7%) patients, focal hypodense lesions in 6/86 (7%) patients, white - matter hypodensity in 2/86 (2.3%) patients, and polymicrogyria in 1/86 (1.2%) patients. in case of generalized seizures [116/276 (10.3%) ], a total of 12 children had ct abnormalities, where cerebral atrophy was seen in 6%, focal hypodense lesion in 0.9%, white - matter hypodensity in 2.6%, and polymicrogyria in 0.9%. in cfs, volumetric reduction of cerebral atrophy was seen in 1.6%, and there was white - matter hypodensity in 10% of patients in the undetermined seizure group. overall cerebral atrophy was the most common finding in our study group comprising 12.3% of patients [table 6 ]. computed tomography findings in studied subjects in our study, a correlation between eeg and ct was made. ct abnormality was seen in 27/276 (9.8%) of patients and eeg abnormality was seen in 155/276 (56.2%) of patients. a total of 43.8% (121/276) of the patients with normal eeg had normal ct, while 1.6% (2/121) of the patients with normal eeg had abnormal ct scans. out of the patients who had abnormal eeg 56.2% (155/276), ct scan abnormality was seen in 16.1% (25/155) and ct was normal in 83.9% (130/155) of the patients, which was statistically significant with p value < 0.000 [tables 7 and 8 ]. electroencephalogram and computed tomography findings in studied subjects correlation of electroencephalogram with computed tomography in our study, mri was done electively in patients in whom eeg was abnormal or ct needed confirmation. a total of 157 patients went for mri, overall abnormal mri was seen in 32 (20.4%), of which 17 (27.0%) patients had partial seizures, 13 (15.8%) patients had generalized seizures, 1 (10%) patient had cfs, and 1 (50%) patient had undetermined seizures. out of the 17 patients with partial seizures who had abnormal mri, 5 (9.8%) had volume loss, 4 (7.8%) had cortical lesions, 3 (5.9%) had white matter lesions, 2 (3.9%) had enlarged ventricles, and 1 (2%) had encephalomalacia. out of the 13 patients with generalized seizure, 5 (8.6%) had cortical lesion, 2 (3.4%) each had volume loss, enlarged ventricles, and 1 (1.7%) each had white matter lesion and encephalomalacia. magnetic resonance imaging findings in studied subjects magnetic resonance imaging findings in studied subjects from our study, a correlation was drawn between eeg and mri. out of 155 patients with abnormal eeg, 30 (19.4%) had abnormal mri. however, 2 patients with normal eeg also had an abnormal mri. the accuracy of picking abnormality by mri, when eeg is abnormal, is 24.8%, which was statistically significant in our study [table 11 ]. correlation of electroencephalogram with magnetic resonance imaging a correlation was seen between ct and mri. all 27 patients with abnormal ct had abnormal mri. however, 5 (3.8%) patients with normal ct also had abnormal mri. therefore, the accuracy of picking abnormality by mri, when ct is normal, is 96.8% [table 12 ]. we intended to estimate the prevalence of abnormal eeg and neuroimaging (ct / mri) and, specifically, correlate between the eeg and neuroimaging. also, the study intended to identify clinical variables (if any) that could predict which children were at high or low risk for abnormal neuroimaging. in our study, overall, 71% of patients with partial seizures and 70.1% of patients with general seizures had abnormal eeg findings. these findings were consistent with similar observations made by al - sulaiman. and doose. on analyzing individual abnormalities in eeg, our study observed that sharp wave and spikes (either alone or both) were the most common abnormality observed. however, homer. and doescher. observed a focal slowing as the most common eeg abnormality. neuroimaging (ct / mri) is a useful tool to determine the etiological diagnosis of seizure. an abundance of such literature pertaining to adult patients exists, some of which report a prevalence of ct abnormalities between 34% and 45%. in our study, the prevalence of neuroimaging abnormality (ct / mri) is 9.8 - 20.4% in children who presented with unprovoked first seizure. this drastic difference we describe underscores the need for different guidelines for the use of neuroimaging in children presenting with new - onset unprovoked seizures. few studies have reported the prevalence of abnormal neuroimaging in children with first unprovoked seizure. landfish. reviewed 56 patients with new - onset seizure but a majority of patients were younger than 2 years, and the most common seizure type was febrile. only 16 patients (29%) had new - onset afebrile seizures. a total of 25 neuroimaging studies were done (44% of patients), including 23 ct procedures and 2 mri procedures, and all were normal, although it is unclear which patients had undergone neuroimaging. the authors recommended that ct or mri should be reserved for children with a history of unprovoked focal seizures, abnormal finding on physical examination, or focal abnormalities on eeg. garvey. reviewed 99 children with new - onset seizures, excluding the patients with underlying neurologic disorders. mcabee. reported that one patient with cfs in their series (5%) had an abnormal ct scan. in a large pediatric study, berg. evaluated 613 children aged 1 months to 15 years with newly diagnosed epilepsy. nearly 80% had neuroimaging done, and relevant lesions were found in 12.7% of these children. in a study of adults and children following a first seizure, found neuroimaging results indicating symptomatic lesions in nearly 14% of them. maytal. reported that in generalized seizures, 82.5% cases had normal ct scan and 17.5% had abnormal ct scan, whereas in partial seizures, 70.8% had normal imaging and abnormal ct was seen in 29.2%, thus showing overall abnormal ct scan in 21.2% of the patients. the prevalence of abnormal neuroimaging in these studies was in the range of 0 - 24%. the proportion of children with febrile seizures was in the range of 17 - 71%. children with febrile seizures (simple or complex) are at low risk of neuroimaging abnormalities. this finding was consistent with our study, in which cfs were present in 23.2% patients and abnormal neuroimaging was seen in 1.6% (1/64) patients. partial seizures are commonly associated with abnormal neuroimaging as compared to generalized seizures. a study conducted by mcbee. on neuroimaging with first - onset seizures observed that the frequency of abnormal neuroimaging was higher in focal seizures than generalized seizures in neurologically normal children. similarly, bachman. also found higher frequency of ct abnormality in patients with partial seizures than generalized and psychomotor seizures. we also found abnormal neuroimaging in 15.5% of patients with focal seizures as against 10% of patients with generalized seizures. the frequency of focal hypodense lesion on neuroimaging was much higher in focal seizures (7%) as compared to generalized seizure (0.9%). overall, common neuroimaging abnormality, both in partial and generalized seizures, was volumetric reduction of cerebral hemisphere consistent with cerebral atrophy, as was shown by simone. in our study, cerebral atrophy was found in 12.3% of patients, hypodense lesion in 7.9%, and polymicrogyria in 2.1% of patients. although the slight increase in the cortical atrophy in our study was, possibly, due to inclusion of cfs patients. abnormal mri was found in 17 (27.0%) patients with partial seizures, 13 (15.8%) patients with generalized seizures, and 1 (10%) patients with cfs. doescher., who conducted a study on a cohort of normal children with newly diagnosed seizures, found abnormal mri in 32.6% of patients. we attributed this higher percentage to the fact that reporting of mri in their study was done repeatedly by more than one examiner. in our study, both eeg and mri were abnormal in 32 (20.4%) patients. however, 125/155 (80.6%) patients who had abnormal eeg, did not show any abnormality on mri. so, the accuracy of picking up abnormality on mri, when eeg is abnormal, is 19.1% by using chi - square test, which is statistically significant. our study showed neuroimaging abnormality in 9.8 - 20.6% patients, with no patient requiring immediate surgical intervention. although in this series the numbers are small, we found that normal eeg did not reliably predict a normal mri. because these studies were obtained at the time of first seizure, we are not aware if lesions on neuroimaging (ct / mri) will predict recurrence of seizure in future. follow - up is required for determining the significance of the abnormalities found on neuroimaging. our study suggests a need for continual assessment of the role of neuroimaging in patients with first seizure. our findings indicate that clinical examination and eeg results are good indicators for neuroimaging, and these can be used as one of the criteria for ordering neuroimaging in new - onset seizures, more so in partial seizure than generalized seizure. this study provides valuable baseline data for a large cohort of children who can be followed up through their developmental maturation and seizure recurrence. additional evaluation through neuroimaging and eeg might demonstrate progressive change and allow retrospective risk analysis. neuroimaging should be strongly considered in children having abnormal eeg, though the patients having normal eeg can be safely discharged without neuroimaging, if follow - up is assured.abnormal eeg in partial seizures increases the risk of having abnormal neuroimaging. but normal eeg in partial seizures does not rule out having an abnormal neuroimaging.in case of generalized seizures, patients with abnormal eeg may have abnormal ct / mri scans. but there are fewer possibilities of a patient with abnormal neuroimaging to have a normal eeg.when eeg is abnormal in first unprovoked seizure, the probability of having abnormal neuroimaging increases as compared to those cases where eeg is normal.a seizure in the setting of fever rarely indicates the presence of an unexpected lesion on neuroimaging.mri has no advantages over ct scan in diagnosis of the first episode of cfs. neuroimaging should be strongly considered in children having abnormal eeg, though the patients having normal eeg can be safely discharged without neuroimaging, if follow - up is assured. normal eeg in partial seizures does not rule out having an abnormal neuroimaging. in case of generalized seizures, patients with abnormal eeg but there are fewer possibilities of a patient with abnormal neuroimaging to have a normal eeg. when eeg is abnormal in first unprovoked seizure, the probability of having abnormal neuroimaging increases as compared to those cases where eeg is normal. a seizure in the setting of fever rarely indicates the presence of an unexpected lesion on neuroimaging. mri has no advantages over ct scan in diagnosis of the first episode of cfs. our findings indicate that clinical examination and eeg results are good indicators for neuroimaging, and these can be used as one of the criteria for ordering neuroimaging in new - onset seizures, more so in partial seizure than generalized seizure. | objectives:(1) to determine the frequency of abnormal neuroimaging in children with new - onset afebrile and complex febrile seizures ; (2) to draw a correlation between electroencephalogram (eeg) and neuroimaging.study design : a hospital - based prospective study.materials and methods : a total of 276 children (6 months to 14 years of age), who presented with new - onset afebrile or complex febrile seizures, underwent eeg and neuroimaging [computed tomography (ct) and/or magnetic resonance imaging (mri)].results : generalized seizures constituted the major seizure group in our study 116/276 (42%) followed by partial seizures 86/276 (31.2%) and complex febrile seizure in 64/276 (23.2%). generalized as well as partial seizures were more common in children aged 6 - 14 years, while complex febrile seizures were predominantly seen in children less than 6 years old. most of the patients with generalized and partial seizures had eeg abnormalities, while eeg abnormalities were uncommon in patients with complex febrile seizures. a total of 27/276 (9.8%) patients with seizure disorder had abnormal ct scans and this abnormality was more common in patients with partial seizures. ct abnormality was seen more commonly in those patients who had an abnormal eeg. eeg and ct correlation showed that patients with abnormal eeg had higher rates of ct abnormality, ie, 16.1% (25/155). abnormal mri was seen in 32/157 (20.4%) of patients ; accuracy of picking abnormality by mri, when eeg was abnormal, was 24.8% (p<0.05).conclusion : our findings indicate that clinical examination and eeg results are good indicators for neuroimaging, and these can be used as one of the criteria for ordering neuroimaging in new - onset seizures. |
paratesticular tumors are infrequent tumors that have a high incidence of malignancy ; they are either soft - tissue tumors or mesothelial neoplasms. paratesticular liposarcomas include all liposarcomas arising in the structures around the testis, including the lower end of the cord. it is felt to arise from the extra peritoneal fat that becomes continuous distally with the fatty tissue of the cord. they commonly present as painless, slowly growing masses that are usually diagnosed as being a lipoma or inguinal hernia. however, complete surgical resection offers the best chance of cure for these patients, and the established method for orchiectomy for testes / cord cancer is through an inguinal incision. a 65-year - old male patient presented with scrotal swelling of 2-year duration in both right and left hemiscrotum, which was gradually progressive in size and non - reducible. on examination, swelling was soft in consistency, testis was palpable posteriorly, and could not get above the swelling. intraoperative, a firm, well - defined tumor, about 20 14 5 cms on the left and 16 14 4 cms on the right side were found at the proximal spermatic cord [figure 1 ] ; no hernia sac was noted at the inguinal canal. bilateral high inguinal orchiectomy was performed. the gross appearance of the specimen revealed a large, soft, well - circumscribed, multilobulated, fat - containing mass adhering to the spermatic cord and testis. the cut surface of the tumor [figure 2 ] showed yellowish and myxoid areas, but without hemorrhage or necrosis. histopathological examination [figures 3 and 4 ] showed sheets and nests of mature adipocytes, scattered atypical cells with hyper chromatic nuclei, and multivacuolated lipoblasts in between on a fibrous and myxoid background. he, however, refused further treatment because he did not have enough money to continue treatment. informed consent has been taken from the patient regarding the publication of the case report. gross specimen of the tumor mass measuring 20 14 5 cms on left and 16 14 4 cms on the right cut section of the specimen showing yellowish and myxoid areas microscopic examination of the mass revealed an encapsulated proliferation consisting of mature adipocytes accompanied by both spindle - shaped cells and multivacuolated lipoblasts microscopic photograph showing mature adipocytes, spindle - shaped cells with hyper chromatic nuclei within the stromal tissue and multivacuolated lipoblasts in between on a fibrous and myxoid background dreyfuss and lubash reported the first documented liposarcoma of the spermatic cord in a 54-year - old male in 1940. liposarcomas are soft - tissue malignancies that are commonly found in the lower extremities and retroperitoneum. they are classified in four histology subtypes (well differentiated, myxoid, pleomorphic, and dedifferentiated). paratesticular tumors have a high incidence of malignancy, which is estimated as 30% in the documented literature, mostly arising from the spermatic cord. most patients present with painless, slowly growing inguinal or scrotal masses, which are usually diagnosed as inguinal hernias or lipoma before surgical intervention. the majority of spermatic cord sarcomas begin their development just below the external inguinal ring and therefore, grows as a scrotal mass rather than as an inguinal mass. the homogenous fatty pattern of well - differentiated paratesticular liposarcomas being similar to lipomas or omentum in the hernia sac makes the differential diagnosis of a liposarcoma difficult through ultrasonograhic studies. hence, even though ultrasonography is the most helpful and commonly used diagnostic tool for differentiating cystic and solid lesions, an abdominal ct scan may be helpful. since they have the tendency for local recurrence after inadequate resection, complete resection, including high ligation of the spermatic cord, is indicated. an intralesional biopsy or surgery the role of adjuvant radiotherapy or chemotherapy remains controversial and is only limited in cases of metastatic tumors or in cases following incomplete resection. radiation therapy may be employed as an adjunct to surgical resection in an attempt to avoid local recurrence. the prognosis of paratesticular liposarcomas depends on the histological cell type, among well- differentiated, dedifferentiated pleomorphic, and myxoid / round cell types. the well - differentiated and myxoid / round cell types have a better prognosis, but they tend to have a high incidence of local recurrence. liposarcomas are the most radiosensitive of all sarcomas and in some cases remission has been achieved with radiotherapy alone. in conclusion, liposarcomas of the spermatic cord represent a rare type of tumors, which are often misdiagnosed preoperatively. being a rare disease and varied type of presentation, paratesticular liposarcoma should be considered as a possibility during the differential diagnosis of fat containing inguino - scrotal mass. | paratesticular liposarcomas are rare tumors and are often reported as isolated cases. patients usually present with a painless scrotal or inguinal mass, mimicking inguinal hernia. they refer to liposarcomas arising from the spermatic cord, testicular tunics, and epididymis. we report a case of bilateral scrotal swelling which was misdiagnosed as inguinal hernia. intraoperative diagnosis of testicular tumor was made. high inguinal orchiectomy was done. histopathological examination revealed it to be liposarcoma of the cord. to our knowledge, there is no reported case of bilateral paratesticular liposarcoma in english literature, hence we report this case. |
the ventricular pacemaker lead could pass the signal from the pacemaker to the pacing site and active the local muscle. then the cardiac excitation spreads to the right and left ventricular and makes the whole heart contract. that 's the way the pacemaker achieves its function for the patients. by connecting to the myocardial however, as the heart beats continuously and the patient breathes every day, the lead will swing accordingly. during the process, it not only makes the lead abrasion or degeneration, but also makes it moving. and the complications of lead dislocation in the clinic was common. to be serious, there would be fatal event - the perforation of active ventricular lead. and this was a 65-year - old male patient presented with 1 month of repetitive dizziness and 1 episode of syncope. physical examination revealed a bp of 120/60 mmhg and a regular cardiac rhythm with heart rate of 60bpm. on auscultation there were no abnormal findings on routine blood test, biochemistry, coagulation, chest x - ray and echocardiogram. electrocardiogram showed sinus bradycardia and his holter monitoring also showed sinus bradycardia with sinus arrest and sino - atrial block and a longest pause of 4.3 s. thus, sick sinus syndrome and adam - stokes syndrome were diagnosed. a dual chamber pacemaker (medtronic sdr303) was implanted with an atrial threshold (passive lead) of 1.0v, sensing of 6.0mv and resistance of 600. ventricular threshold (active lead) was 1.0v and sensing was 6.0mv while resistance was 780.the patient was discharged 1 week later with suture removed. he presented to hospital with sudden onset of chest pain with exacerbation after taking deep breath 1.5 month after procedure. pacemaker programming showed both pacing and sensing abnormality with threshold of > 5.0v and resistance of 1200. chest x - ray revealed lead perforation in right ventricle and a concomitant left pneumothorax (10% compression) (figure 1a). considering the fact that there was high risk to remove ventricular lead, spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to septum. patient was asymptomatic after procedure and repeat chest x - ray did not show abnormal location of previous lead. there was no evident pericardial effusion on echocardiogram and the patient remained uneventful during 6-month follow - up after procedure. figure 1a) chest x - ray revealed perforation of myocardium by active lead of rv ; b) withdraw spiral tip of first lead and implant a new active lead into septum. a) chest x - ray revealed perforation of myocardium by active lead of rv ; b) withdraw spiral tip of first lead and implant a new active lead into septum. cardiac perforation after permanent pacemaker implantation was first reported in 1996 by crow. by definition, it is cardiac perforation happened during or after pacemaker implantation and is related to pacing leads. usually the diagnosis can be established if the tip of the pacing lead exceeds 3 mm of the cardiac contour. cardiac perforation happened within 1 month after procedure is referred to as early perforation. whereas that happened more than 1 month after procedure is referred to as delayed perforation. with the development of contemporary pacing leads and improvement of implantation technique, according to retrospective analysis 2535 pacemaker implantations by zado from us in 2006, the incidence of delayed perforation was 0.17%. there was no evidence of lead perforation during procedure, while cardiac perforation occurred 24 h or several days or even 3 years after procedure. common causes for cardiac perforation after pacemaker implantation were : on or previous prescription of corticosteroids, use of active lead, excessive lead length or tension, bmi<20 and use of bipolar electrode. most cases presented asymptomatically or only presented as pacing or sensing abnormality, which usually underwent unnoticed. severe cases could be presented as pulmonary embolism, hemopneumothorax, cardiac tamponade or even sudden death. cardiac perforation typically presented as chest pain5 or extracardiac muscle stimulation by pacing lead, e.g. intercostal muscle, mediastinum and diaphragm. if cardiac tamponade occurred, consequently it will be presented as palpitation, dyspnea, cyanosis and agitation. the key issue of management of cardiac perforation caused by pacing lead is whether perforated lead needs treatment and if so, how. currently, there are not adequate proofs as to which strategy is best. generally speaking, extraction of pacing lead and implantation of new lead under echocardiogram guidance and surgical backup is preferred with high success rate, though experience is limited. the treatment of delayed cardiac perforation as to whether treat it conservatively or surgically and whether to remain or remove the perforated lead are still high debatable and evidence is scarce. liu jian reported a case of delayed chronic perforation 2 years after implantation of a ventricular passive lead. there was no symptom of cardiac tamponade and a new lead was implanted while previous lead was remained. li xuebin reported 8 cases of acute perforation with the longest delay after procedure of 17 days. reported 3 cases of cardiac tamponade caused by perforation of atrial active lead, among which 2 received open chest surgery and relocation of pacing lead. zado reported 5 cases of delayed cardiac perforation, among which only 2 had alteration in pacing parameters, 2 only underwent pericardiocentesis, 2 pericardial drainage, 1 removal of previous lead when pericardial drainage was in situ, 2 underwent open chest surgery. the patient presented suddenly with chest pain typically after taking deep breath 1.5 year after procedure. chest x - ray revealed lead perforation in right ventricle and a concomitant left pneumothorax (10% compression). the possible reason for the perforation could be : use of ventricular active and bipolar lead, lean body stature, lead tip perforated although various parameters were normal, excessive lead length or tension. pneumothorax was caused by piercing of lung tissue by spiral lead and chest pain was also deemed to be related to this reason. after literature review the feasible options were : maintain previous lead while withdraw spiral tip and simultaneous implantation of a new lead ; surgical consultation and open chest surgery ; removal and relocation of previous lead under pericardial drainage and surgical backup. considering the fact that the patient was hemodynamically stable and without pericardial effusion, it was possible that perforation was contained by blood clot and fat tissue. thus, there was high risk to remove ventricular lead or referred the patient to surgery. first option was adopted to withdraw spiral tip of previous ventricular lead followed by implantation of a new ventricular active lead to septum. patient was asymptomatic after procedure and repeat chest x - ray did not show abnormal location of previous lead. there was no evident pericardial effusion on echocardiogram and the patient remained uneventful during 6 month follow - up after procedure. acute or chronic cardiac perforation caused by pacing lead is not rare and warrant caution and prompt management by clinicians. remain the previous lead and implantation of a new lead might be a safe treatment when patient is hemodynamically stable and there is no cardiac tamponade. | a 65-year - old man was admitted as for one month of repetitive dizziness and one episode of syncope. electrocardiogram showed sinus bradycardia and his holter monitoring also showed sinus bradycardia with sinus arrest, sino - atrial block and a longest pause of 4.3 s. then sick sinus syndrome and adam - stokes syndrome were diagnosed. then a dual chamber pacemaker (medtronic sdr303) was implanted and the parameters were normal by detection. the patient was discharged 1 week later with suture removed. then 1.5 month late the patient was presented to hospital once again for sudden onset of chest pain with exacerbation after taking deep breath. pacemaker programming showed both pacing and sensing abnormality with threshold of > 5.0v and resistance of 1200. lead perforation was revealed by chest x - ray and confirmed by echocardiogram. considering the fact that there was high risk to remove ventricular lead, spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to the septum. previous ventricular lead was maintained. as we know that the complications of lead perforation in the clinic was rare. here we discuss the clinical management and the possible reasons for cardiac perforation of active ventricular lead. |
retinal vein occlusions (rvos) are the second most common visually disabling disease affecting the retina, after diabetic retinopathy. obstruction of retinal venous flow leads to damage of the vasculature, hemorrhage, and tissue ischemia. occlusions affecting the central retinal vein, or central retinal vein occlusion (crvo), affect the entire retina, while those affecting lesser tributaries of the venous circulation, the so - called branch retinal vein occlusion (brvo), affect a portion of the retina. despite the fact that the disease entity has been known to exist for over 100 years, current treatment options often still leave patients with clinically problematic visual disturbances and overall increased morbidity. rvo generally affects patients in middle age and the elderly population, and several studies have identified systemic risk factors, such as hypertension, diabetes, systemic vascular disease, glaucoma, and hypercoagulable states [3, 4 ]. although proliferative vascular changes can cause significant morbidity (particularly due to subsequent vitreous hemorrhage and neovascular glaucoma), the main reason for decreased visual acuity in both crvo and brvo is macular edema. as a result, elucidation of the causes of, as well as treatment for, macular edema has been at the center of large - scale studies on patients with rvo. while the causes for rvo are multifactorial, with local and systemic factors being identified as etiologic, most of the literature generally implicates vascular and inflammatory mediators as being particularly salient [68 ]. prior to the advent of intravitreal drug delivery, treatment for macular edema for crvo and brvo was observation and grid laser photocoagulation, respectively, the latter of which resolved macular edema slowly even under optimal circumstances. the subsequent creation of intravitreal medicines that block vascular endothelial growth factor (vegf) and the intravitreal delivery of corticosteroids for rvo has led to better clinical outcomes overall. while the focus of much of the literature is currently on the role of anti - vegf medications in the treatment of rvo, the role of inflammation in both pathogenesis and treatment of rvo is equally exigent. both systemic and local inflammations have been hypothesized to play a significant role in the etiology of rvo. the predisposing systemic risk factors for rvo include hypertension, diabetes, dyslipidemia, and elevated plasma levels of homocysteine [1113 ]. atherosclerosis, a chronic, low - grade inflammatory condition, has been studied extensively in relation to rvo. indeed, the systemic risk factors that predispose patients to rvo are also independently associated with atherosclerosis [11, 13 ]. the initial pathological findings of this condition are composed of monocyte - derived macrophages and t - lymphocytes (purely inflammatory lesions) which later progress to thrombus and clot formation. results pertaining to the hypothesis of atherosclerosis as a risk factor for rvo have been mixed. large population - based cross - sectional studies have found that, while the prevalence of rvo is fairly similar across ethnic groups, atherosclerotic disease and markers of inflammation, such as c - reactive protein, were not associated with the disease. in addition, certain genetic polymorphisms that had been previously implicated in atherogenesis, inflammation, and coagulation did not show association with brvo or crvo [16, 17 ]. however, other reports have shown potential links between atherosclerosis (and by extension, systemic inflammation) and rvo. in particular, recent studies have shown that patients with rvo have an increased risk of asymptomatic ipsilateral carotid artery plaques, and those with brvo often also have decreased aortic distensibility and elasticity, a finding frequently found in patients with atherosclerosis [18, 19 ]. in addition, pathological studies have shown an atherosclerotic retinal artery at the lamina cribrosa in some patients with crvo. another mechanism by which systemic inflammation is proposed to lead to rvo is through the induction of systemic hypercoagulability. many inflammatory chemokines / cytokines are prothrombogenic ; for example, interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha all simultaneously upregulate tissue factor, which is a major activator of the extrinsic coagulation cascade pathway, and downregulate tissue type plasminogen activator, which disrupts fibrinolysis [2123 ]. in particular, homocysteine, a plasma element found elevated in patients with chronic inflammatory conditions, such as atherosclerosis, as well as in patients with errors of protein metabolism (homocysteinemia / homocystinuria), can cause adverse systemic thrombotic events. patients suffering from grossly elevated plasma levels of homocysteine often develop deep vein thromboses, myocardial infarctions, carotid atherosclerosis, and stroke. in a similar fashion to other inflammatory - mediated processes, proposed mechanisms of thrombosis include inhibition of plasminogen activator, inhibition of protein c activation, activation of factor v, and the inducement of endothelial cell dysfunction [2527 ]. perhaps unsurprisingly, given the strong possible link between hyperhomocysteinemia and hypercoagulation, subsequent case control studies between patients with and without crvo have demonstrated a robust correlation between crvo and elevated plasma levels of homocysteine [28, 29 ]. however, other studies have rightfully pointed out that, given that elevated levels of plasma homocysteine are found in various other chronic inflammatory states, such as atherosclerosis, the association of homocysteinemia with rvo is likely multifactorial. local inflammation within the eye has also been implicated in the pathogenesis of rvo. in vivo assessment of the vitreous fluid in patients with rvo has demonstrated elevated levels of proinflammatory mediators and lower levels of anti - inflammatory cytokines [31, 32 ]. in particular, in a major study on inflammatory immune mediators in a group of vitreoretinal diseases, patients with rvo had elevated levels of interleukin-6, interleukin-8, and monocyte chemoattractant protein-1, and patients with crvo had elevated levels of vegf, all of which are considered highly proinflammatory. in follow - up studies, patients with macular edema from both brvo and crvo were shown to have increased levels of soluble intercellular adhesion molecule-1 (proinflammatory) and decreased levels of pigment epithelium derived factor (anti - inflammatory) [34, 35 ]. unsurprisingly, the literature suggests that for larger order vessel disruptions, such as those affecting the central retinal vein or a larger branch retinal vein (major brvo), there are even higher elevations and reductions of the aforementioned pro - inflammatory and anti - inflammatory cytokines, respectively, as compared to smaller branch vessel disruptions [32, 36 ]. of particular note is the fact that vegf is classified as a pro - inflammatory cytokine ; while vegf is famously known for its central role in retinal angiogenesis, recent studies have revealed its role in permitting leukocyte infiltration into the retina a key initial step in the inflammatory pathway [37, 38 ]. macular edema itself has been shown to result from prolonged inflammatory states, such as those seen in uveitis. while the exact mechanism for how inflammation actually causes macular edema is still unclear, the prevailing theory includes the instigation of pro - inflammatory cytokines that subsequently damage retinal cells, particularly retinal pigment epithelial cells, which leads to fluid leakage into the retina. in addition, the retinal ischemia seen with rvo has also been postulated to lead to a pro - inflammatory milieu, with the added insult of increased vascular permeability partially due to a breakdown of the blood - retinal barrier. given these conditions, treatment options for rvo preventing inflammation while the mainstay of treatment for systemic inflammatory states has been oral or intravenous corticosteroids, this method of administration precluded their effective use for ocular conditions given the side effect profile of long - term steroid use. in addition, topical steroids do not penetrate the posterior segment of the eye in an efficacious manner. however, injecting corticosteroids directly into the vitreous cavity allows for a targeted, high dose use of the medications for ocular inflammatory conditions with a low side effect profile. currently, the major anti - inflammatory medications in use for the treatment of rvo are intravitreal triamcinolone acetonide (ivta) and the newly developed dexamethasone intravitreal implant. triamcinolone acetonide is a synthetic glucocorticoid that has a potency that is five times that of cortisol and has been reported to remain in the eye for months to years after its initial injection [41, 42 ]. initial use of ivta for treatment of crvo resulted in significantly improved anatomical changes within the macula [8, 43, 44 ]. as a result, the score (standard care versus corticosteroid for retinal vein occlusion) trial was launched by the national eye institute. the study consisted of two multicenter, randomized controlled clinical trials comparing the efficacy of ivta versus standard of care for both brvo and crvo [45, 46 ]. the score - brvo arm placed patients in cohort groups which received 1 mg of ivta, 4 mg of ivta, or standard of care (macular grid laser photocoagulation). the results demonstrated no difference between the three groups in terms of visual outcome ; however, there was an increased incidence of adverse side effects such as glaucoma, cataract, and injection - related problems in the ivta groups relative to the laser group. expectantly, the adverse side effects were more pronounced in patients receiving the higher dosage of ivta. as a result, the study concluded that for brvo, macular grid laser photocoagulation should remain the gold standard for treatment. the score - crvo arm placed patients in cohorts similar to the score - brvo arm ; however, the results demonstrated that both ivta groups were superior to observation (standard of care for crvo) in both visual acuity and anatomic resolution of macular edema. these beneficial changes occurred as early as 4 months into treatment and persisted for 24 months. the study also demonstrated a reduced incidence of adverse side effects in the 1 mg ivta group ; as a result, this dosage has been preferred by some in the treatment of crvo. given the partial success of temporary intravitreal corticosteroids, a method of delivering corticosteroids in a manner that obviated the need for multiple injections was developed. the dexamethasone implant is a biodegradable copolymer of both lactic and glycolic acids with micronized dexamethasone that gradually releases the dose of the steroid over a period of months via the pars plana. the geneva trials were two phase iii trials that tested the effect of dexamethasone implants (in the 0.35 mg and 0.7 mg dosages) versus sham injections in patients with brvo and crvo [47, 48 ]. the results for the brvo study group were mixed ; while there was a trend towards better visual acuity in the dexamethasone implant groups after 6 months, there was a statistically significant improvement of acuity in the dexamethasone implant groups after 3 months. a similar patients tolerated the implant well, with a minority of patients developing medically manageable glaucoma and cataract. given the results of the geneva trials, some advocate use of the implant for patients with a relatively short duration of macular edema. others have suggested that the dexamethasone implant may be useful for less frequent occurrences of macular edema secondary to rvo, such as those occurring in postvitrectomized eyes with crvo, and those with long - standing brvo and chronic edema [49, 50 ]. however, considering that the pathogenesis of inflammation in rvo also includes vegf as a key mediating cytokine, the advent of intravitreal anti - vegf medications and their role in the treatment of rvo are especially salient. ranibizumab is a monoclonal, humanized antibody fragment that binds to all vegf isomers. two randomized controlled trials were established to determine the efficacy and safety of ranibizumab in the treatment of rvo : bravo (brvo) and cruise (crvo) [51, 52 ]. in both bravo and cruise studies, patients with fovea involving macular edema within the prior 12 months were given monthly ranibizumab injections of either 0.3 mg, 0.5 mg, or sham injections. in the bravo study, patients who were not responding to treatment were eligible to receive rescue laser photocoagulation (standard of care) after 3 months. at 6 months of treatment, patients in the ranibizumab groups in both studies had significantly higher average gains in visual acuity, significantly higher proportions of patients gaining at least 15 letters of vision, and significantly lower mean foveal thicknesses relative to the sham injection group. in addition, patients maintained this vision with continued injections through 12 months ; intriguingly, patients in the sham group who were subsequently given ranibizumab injections after the 6-month period enjoyed beneficial visual and anatomic changes however, their final visual acuities were generally less than those in the ranibizumab groups, engendering a discussion on whether there was a visual penalty resulting from a delay in treatment [53, 54 ]. similarly beneficial effects in smaller studies have been noted with another anti - vegf antibody, bevacizumab ; however, many of the studies also mention a high recurrence rate and relatively short - term - efficacy [5560 ]. given the beneficial treatment outcomes of both intravitreal steroid and intravitreal anti - vegf medications, a few reports have attempted to ascertain whether a synergistic effect might exist. one study found no significant difference in outcome between patients with crvo who only received bevacizumab versus patients who received both bevacizumab and triamcinolone. another study attempted to assess whether patients with rvo who received both bevacizumab and a dexamethasone implant (0.7 mg) had significantly better outcomes than those who received only the dexamethasone implant. the patients in the combination group were given the dexamethasone implant 2 weeks after the first injection of bevacizumab. the primary outcome was the time required for reinjection based on existing oct and visual data. while most patients gained vision, a small minority did not require a retreatment with an additional bevacizumab injection during the 6-month study. while the data suggests that there may be a synergy between anti - vegf medications and steroids, further study is required. while the causes for rvo are multifactorial, both local and systemic inflammations have been found to be highly contributory factors. along with photocoagulation, medications that reduce the level of inflammation in the eye, specifically triamcinolone and the dexamethasone implant, have been shown to provide beneficial results for patients with certain forms of rvo. coupled with the explosion of anti - vegf medications, such as ranibizumab and bevacizumab, the treatment of rvo is destined to change. further study of the role of inflammation in the pathogenesis and propagation of rvo will aid in the identification of therapeutic targets and the development of new treatment modalities for this disease. | retinal vein occlusion is a common, vision - threatening vascular disorder. the role of inflammation in the pathogenesis and clinical consequences of retinal vein occlusion is a topic of growing interest. it has long been recognized that systemic inflammatory disorders, such as autoimmune disease, are a significant risk factor for this condition. a number of more recent laboratory and clinical studies have begun to elucidate the role inflammation may play in the molecular pathways responsible for the vision - impairing consequences of retinal vein occlusion, such as macular edema. this improved understanding of the role of inflammation in retinal vein occlusion has allowed the development of new treatments for the disorder, with additional therapeutic targets and strategies to be identified as our understanding of the topic increases. |
about 75%80% of cutaneous melanomas originate on healthy skin, therefore only 20%25% of melanomas are thought to develop on a cutaneous lesion that we can identify as a clinical precursor. it remains to be established whether or not the so - called precursors are to be considered as precancerous lesions or, rather, melanoma insurgence on a pre - existing lesion could occur due to a merely statistic percentage. this can be substained when nevi are considered as simply melanocytic aggregates, the risk of developing a melanoma being genetically determined, enhanced by some environmental factors, and theoretically present on the whole skin. of course, different biological conditions can arise in those rare instances in which a cutaneous melanoma develops on skin where the ability to repair the photo - induced damage is altered genetically as xeroderma pigmentosum, with a reported incidence of melanoma approximately 2000 times greater, or in case of genetic or acquired immunodeficiency, that is, cases of immune impairment in organ transplant recipients or in patients affected by hodgkin 's lymphoma. we can identify three main groups of cutaneous pigmented lesions that could be represented as melanoma precursors : (a) congenital melanocytic nevi, (b) dysplastic or atypical nevi, and (c) acquired melanocytic nevi. the main aim of this paper should be to clarify the clinical impact of the so - called melanoma precursor and, above all, an attempt to understand which clinical behavior could be more appropriate for each group. the most simple and obvious definition for congenital melanocytic nevus could be melanocytic nevus present at birth ; however, some lesions showing the clinicopathologic features of congenital nevus can develop also during early childhood. the clinicopathologic diagnosis of congenital nevus is usually made when observing a cutaneous pigmented plaque, with well - defined borders, light to dark brown in color, often with follicular activation, conventionally distinguished in small (20 cm), characterized by the presence of melanocytes in the two lower thirds of the dermis, with occasional extension to the subcutaneous tissue. nevus cells, appearing isolated or in regular rows and aggregates, can be found among collagen fibers in the reticular dermis, with tendency to periadnexal, perineurial, and perivascular disposition. however, some congenital nevi do not show such histopathologic features ; that happens in particular for small congenital nevi and in a not defined percentage of congenital nevi of medium size. this clinicopathologic disagreement could determine some discrepancies in the case of studies trying to establish the degree of melanoma risk of congenital nevi based exclusively on histopathologic grounds. the correct quantification of the incidence of melanoma associated with a congenital nevus seems to be a problem yet unsolved. in 1982 a study found a risk of melanoma as 21 times higher in patients whose congenital nevi were diagnosed clinically and anamnestically, while the risk was only others had previously demonstrated that the reliability of the questionnaire compiled by the parents was not so high, and only a third of the lesions described as congenital nevus were shown as such on the basis of the histologic parameters. moreover, in this study an 8.1% incidence of melanoma associated to nevi with histological characteristics of congenital nevus was reported, an association 8 times higher when compared to other studies. an investigation on 48 congenital nevi with diameter less than 10 cm revealed only two cases showing nevus cells in the lower third of the dermis or in the subcutaneous tissue. melanomas arising in congenital nevus were of junctional origin and all of them developed after 18 years of age. none of these melanomas showed the neuromesenchymal features frequently observed in melanomas associated to giant congenital nevi. indeed, the nonepidermic insurgence of a melanoma on small congenital nevi is considered exceptional, unlike giant congenital nevi. in another study the risk of melanoma was evaluated in 265 cases of congenital nevi : no melanomas were observed in the 232 individuals with a congenital nevus involving less than 5% of the body area ; in the 33 cases presenting nevi involving more than 5% of the body surface two melanomas were diagnosed. in a further clinical investigation, on 230 medium - sized congenital nevi followed until 26 years of age, no melanoma was observed. on the contrary, in giant congenital nevi, the melanoma 's risk has been estimated between 5% and 20%. in another evaluation, 46 cases of giant congenital nevus were followed and it was established that the cumulative risk of melanoma was 5.7%. the melanocytic tumor that develops on giant congenital nevus frequently shows a heterogenous morphology determined by transformation of neural crest cells in a heterotopic site probably for an altered migration in the embryogenetic phase. there is also a risk of extracutaneous melanoma, in particular involving the leptomeninx, in patients with neurocutaneous melanosis. moreover, it should be emphasized that approximately 60% of melanomas developing in giant congenital nevi arise during the first decade of life, in particular within the first 5 years. a further problem is due to the fact that, as about two thirds of melanomas in giant congenital nevi are of nonepidermic origin, clinical and dermoscopic observations, which should allow early detection of a junctional melanoma, are not helpful in this cases. on the contrary, in small congenital nevi melanoma can develop, as happens in acquired melanocytic nevi, at the dermoepidermal junction presenting a risk that seems to be extremely low, therefore the prophylactic excision would not be immediately indicated. if surgical intervention is planned, this can be performed during the pubertal age because the malignant transformation in prepubertal age is an exceptional event. on the contrary, in giant congenital nevi, due to the high risk of developing a melanocytic tumor with neuro - mesenchymal features, surgical exeresis (often not easy) the deepening of the surgical toilette up to the fascia does not guarantee to reach complete excision, since primordial neuromesenchimal cells can remain in deep tissues. in medium - sized congenital nevi the precancerous risk could depend more on the histopathologic pattern of the lesion than on the size of the nevus. a good part of these intermediate nevi, as usually observed in small congenital nevi, can lack melanocytes in deeper layers of the dermis. therefore a small incisional punch biopsy on medium - sized congenital nevi could sometimes allow a better prognostic evaluation. dysplastic nevus syndrome giant congenital nevus superficial spreading melanoma dysplastic nevus was first observed and described in 1978 in 6 families with an increased incidence of melanoma. such pigmented lesions showed heterogeneous features regarding shape, color and size, they appeared mainly localized in the upper portion of the trunk and on limbs, they were detected in a great number in each individual, and those families in which these nevi were observed showed a higher incidence of melanoma. this condition has been subsequently described under various denominations, that is, dysplastic nevus syndrome, atypical familial nevus syndrome, and melanoma syndrome.[1921 ] dysplastic nevi can be observed in patients with or without melanoma ; an important clinical feature seems to be its familial or sporadic presentation. usually, dysplastic nevi show a diameter greater than 5 mm appearing as a macular lesion or a small plaque with or without a central relief, the color appearing light to dark brown often distributed irregularly. they are quite common in clinical practice, representing approximately 5% of cutaneous histopathologic reports. clinically, dysplastic nevi differ from common acquired nevi for appearing during pubertal age or even childhood, showing a dynamic behavior during the adult life, and also for continuing to develop during life, also beyond the fourth decade. a consensus conference defined some criteria, that is, the presence of architectural disorder with asymmetry, subepidermal fibroplasia (concentric or lamellar), atypical melanocytic hyperplasia with fusiform or epithelioid cells isolated or arranged in nests appearing irregular in shape and size with the formation of bridges between epidermal rete ridges. cytological atypia of melanocytes can appear in variable degree, as well as a lymphomonocytic inflammatory infiltrate in the superficial dermis. atypical nevus and familial melanoma syndrome with the presence of melanoma in one or more blood relatives of first or second degree, a great number of melanocytic nevi with atypical clinical aspect, often more than 50, and histopathologic features of dysplastic nevus. nowadays, the clinical evidence of familial dysplastic nevus syndrome is not called into question. the risk of developing a melanoma would be 184 times greater in patients with familial dysplastic nevus without familial melanoma, whereas it would be 500 times greater in patients with familial dysplastic nevus and familial history of melanoma subjects presenting sporadic dysplastic nevus are considered by some authors as patients having an increased risk of melanoma, however, in lower extent than subjects with familial dysplastic nevus. with increasing of the number of dysplastic nevi in the same patient, the risk of correlated melanoma would also increase. a remarkable nosologic problem on the concept of nonfamilial dysplastic nevus is represented by the clinicohistologic correlation that, often, is not coherent, as it is possible to observe a nevus clinically dysplastic that histologically reveals itself as normal and vice - versa. therefore, the possibility to predict histologic dysplasia on clinical grounds is quite limited. in a study on 91 a further critical evaluation, using only objective histologic criteria for diagnosis of dysplastic nevus, paradoxically established an incidence of 53% dysplastic nevi in caucasian individuals. common melanocytic nevi are constituted by aggregates of nevus cells (or melanocytes) which in the great majority of caucasian population clinically appear as small cutaneous macular or maculopapular lesions, colored from brown to dark brown, measuring a few millimeters in diameter. apart from this common melanocytic flat nevus, the rest of the acquired melanocytic nevi with peculiar features observed in caucasian individuals can be defined, following a well - known eponymic classification, as clark 's, unna 's, miescher 's, spitz 's, and reed 's nevus. histologically, melanocytic nevi are classified as junctional (regular aggregates of melanocytes located at the tips of epidermal rete ridges), intradermal (regular cords of nevus cells in the dermis with progressive maturation in depth), compound (with both the components), and lentiginous (with a regular epidermal hyperplasia). apart from the small flat pigmented common nevus, clark 's nevi constitute the great majority of acquired melanocytic nevi ; they appear as macular, maculopapular or small plaque lesions, light to dark brown in color, with a round or ovoid shape, with a variable diameter from a few millimeters up to one centimeter, sometimes with irregular borders and/or slight asymmetry, a smooth surface or a slightly raised palpable area found in the center of the lesion. in clark 's nevi one can occasionally observe a small regular regressive area appearing very limited when compared to the total area of the nevus. unna 's nevi appear as exophytic, pedunculated or sessile lesions, dark brown in color, measuring a few millimeters, with soft texture and smooth surface. miescher 's nevi present as papular lesions, a few millimeters in diameter, light brown or of skin colored, with a dome - shaped smooth surface and regular borders, generally localized on the face. spitz 's nevi usually develop during childhood, they are frequently localized on the face, appearing as red / pink to light brown papular lesions, with smooth surface and regular borders ; histologically, they show epithelioid or fusiform melanocytes, usually hypopigmented, forming within the epidermis a number of vertically arranged ovoid nests, with epidermal hyperplasia and typical clefts ; small eosinophilic globules (kamino 's bodies), residual of basal membrane, can be observed. melanocytes can penetrate deeper in the dermis with some cell maturation and occasional slight lymphomonocytic inflammatory infiltrate. reed 's nevi, considered as a variant of spitz 's nevi formed by pigmented spindle cells, clinically appear as round to ovoid papules or plaques, heavily pigmented, dark brown to black in color, symmetrical, with onset in the young adult, mainly on the limbs, slightly palpable, with a typical dermoscopic pattern characterized by radial streaks all around the perimeter (starburst pattern) ; it is a current opinion, we do not know if absolutely right, to remove surgically reed 's nevi after the pubertal age. blue nevus appears like a small papule or plaque lesion, frequently localized on the dorsal aspect of hands and feet, with a homogeneous bluish color, smooth surface, histologically formed by the presence of dendritic melanocytes localized in the dermis, accompanied by occasional melanophages and fibrous stroma. the so - called malignant blue nevus is a rare melanoma developing within a blue nevus or differentiating towards it. other less frequent nevi must not be forgotten, like sutton nevus or halo nevus (a round, regular vitiligo - like halo around the nevus), meyerson 's nevus (with spongiotic inflammatory reaction) and barr 's nevus (with desmoplastic histologic pattern). acquired melanocytic nevi usually appear after the first year of life and can increase in number and diameter during (and also after) the somatic growth, normally not exceeding 5 millimeters in diameter. only 20% of adults would not show common flat nevi or clark 's nevi larger than 2 millimeters. in any case, the presence of acquired melanocytic nevi in each population is determined by genetic, environmental and probably immunologic factors. it has been established that patients with more than 50 melanocytic nevi should have an increased relative risk for melanoma, quantified in 12.1 in the absence of clinical criteria for dysplastic or atypical nevi, whereas in individuals with clinically atypical nevi, that is, diameter greater than 7 mm, irregular borders and not homogeneous color, the relative risk for melanoma should grow to 54. in another study, subjects with a total number of nevi between 50 and 100 had a relative risk for melanoma of 3.2, compared to a control group composed of individuals with a total number of nevi between 0 and 4. patients with more than 100 nevi should have a risk of 7.7. in a further investigation, the relative risk for melanoma in central europe, in subjects with more than 50 nevi,, the relative risk for melanoma does not depend on the presence of clinically atypical nevi but only on the total number of clark 's nevi ; patients with more than 120 nevi had a 19.6 risk and patients with nevi in sun unexposed areas should be looked upon as a subgroup with a major risk. screening for melanoma seems to be more important when performed in mature and old age. some methods, such as (fluorescence) in situ hybridization and mutation analysis can detect cytogenetic alterations in melanocytic tumors. some mutations, early events in melanocytic tumors, in braf (melanocytic nevi), nras (congenital nevi), hras (spitz nevi), and gnaq (blue nevi) can all cause activation of the mitogen - activated protein kinase (mapk) signaling pathway in the initiation of melanocytic tumors. this genetic heterogeneity in distinct types of nevi and melanomas could be used in the future for the development of molecular tests for diagnostic purposes. dysplastic nevi, clinically atypical with histologic architectural disorder and cytologic atypia, are significant only in relation to melanoma, as mimickers of melanoma, as markers of individuals at increased risk of developing melanoma, and maybe as potential and occasional actual precursors of melanoma. individuals with dysplastic nevi may have deficient dna repair, and dysplastic nevi lesions are associated with overexpression of pheomelanin, which may lead to increased oxidative damage and increased potential for dna damage and tumor progression. a recent, very impressive study on oncogenic braf - positive dysplastic nevi and the tumor suppressor igfbp7 challenged the concept of dysplastic nevus as precursor lesion of cutaneous melanoma. although the occurrence of melanoma in small and intermediate congenital melanocytic nevi is very uncommon, there is a high risk in large congenital melanocytic nevi, in particular those arising in the so - called bathing trunk distribution, risk estimated to be from 2.5% to 5%, highest in the first 510 years of life, with significant mortality. large congenital melanocytic nevi, mainly those overlying the posterior axis and occurring within multiple satellite melanocytic nevi, are also associated with the development of neurocutaneous melanosis, with neurologic and neurodevelopmental sequelae, associated with a high risk of primary central nervous system melanoma. it is very important to distinguish the familial dysplastic nevus syndrome, which is a strong risk factor for cutaneous melanoma, from not familial (sporadic) dysplastic nevus, in which the risk for melanoma would depend on the total number of melanocytic nevi, on the phototype and on the relationship to environmental factors, keeping in mind that a great number of clark 's nevi constitute a risk factor for cutaneous melanoma in caucasian patients. a current possible explanation of this could be that the patient with many nevi, having a greater number of nevus cells, or melanocytes, has also a greater probability to develop a melanoma. but, in reality, the great majority of melanomas (75%80%) develop on healthy skin, therefore the clinical expression of many clark 's nevi, or sporadic dysplastic nevi, could simply be one of the aspects of the patient phenotype, whose skin has a greater relative risk for melanoma, a genetically encoded risk jointly enhanced by environmental factors. | we can identify three main groups of cutaneous pigmented lesions that could be represented as melanoma precursors : (a) congenital melanocytic nevi, (b) dysplastic or atypical nevi, and (c) acquired melanocytic nevi. the occurrence of melanoma in small and intermediate congenital melanocytic nevi is very uncommon, but there is a high risk in large congenital melanocytic nevi, in particular those arising in the so - called bathing trunk distribution. it is very important to distinguish the familial dysplastic nevus syndrome, which is a strong risk factor for cutaneous melanoma, from not familial (sporadic) dysplastic nevus, in which the risk for melanoma would depend on the total number of melanocytic nevi, phototype, and on the relationship to environmental factors. |
in the previous issue of critical care hadian and colleagues compare the performances of the three best known examples of pulse contour systems - lidco plus, picco plus and flotrac - against thermodilution. an experimental design was used based on cardiac surgery patients in the first 4 hours after surgery, in which cardiac output was managed using four different therapeutic interventions - fluid bolus, vasoconstrictor, vasodilator and inotrope - which should have provided a vigorous test of trending ability when compared with the alternative of sampling at regular time intervals. the authors used a standard and now well - established statistical approach of bland and altman analysis, determining percentage errors and concordance trend analysis that included an exclusion zone (changes < 0.5 l / minute). the results show that only the lidco plus system provided an acceptable level of agreement with thermodilution (percentage limits none of the three systems provided satisfactory trending, however, with concordance rates (74%, 72% and 59%) well below the required 90 to 95% for good trending. the reliability of the pulse contour method is known to be susceptible to changes in peripheral resistance and the study protocol involved vasoconstrictor and vasodilator drugs, which may explain these poor trending results. this study helps to confirm what is already suspected about the reliability of pulse contour devices ; that these devices do not track changes in cardiac output reliably. although there are many recent published studies evaluating pulse contour devices, the present one provides a very exacting examination and also compares the three main brands of pulse contour monitor. the study could be faulted, however, because a now out of date flotrac/vigeleo software version was used. the flotrac has been criticised for failing to compensate for low peripheral resistance states. in response, edwards lifesciences (irvine, ca, usa) produced a new third - generation software version (for example, version 3.02) known as dynamic tone technology to overcome this limitation. the authors also used continuous cardiac output readings as their reference standard if a heated wire pulmonary artery catheter was in situ. validation should ideally be based on readings from single bolus thermodilution cardiac output measurements as these are said to be the most reliable. there are several studies that show continuous cardiac output to be as accurate as single bolus thermodilution. continuous cardiac output takes several minutes to stabilise and provide a valid reading, however, which makes it less reliable when measuring trends. one must therefore be cautious interpreting data from this study, as the bland and altman analyses and the concordance analyses may use reference data that have a wider spread than usual and thus wider acceptance criteria. the paper is made much harder to comprehend due to the many cross - comparisons, in the form of bland and altman and four - quadrant concordance plots, which show agreement between the three pulse contour methods. these comparisons do, however, suggest that these three pulse contour methods are not interchangeable. the reason given by the authors is the use of different proprietary algorithms, which measure different aspects of the pulse contour waveform - which is an interesting point. furthermore, nine out of 17 patients had femoral rather than radial arterial lines inserted. there is growing evidence that the site of puncture affects the shape of the arterial trace and thus pulse contour measurements. the more distal the puncture site, the greater the influence of acoustic reflections from vessel branching, and the extent of wave reflection also varies quite dramatically with blood vessel constriction and dilatation. the puncture site thus seems to be an important determinant of the success of pulse contour measurements and should be paid more attention. it is one of several recent clinical studies that show the pulse contour does not reliably reflect changes in cardiac output in haemodynamically unstable patients. excuses can be made that the thermodilution reference method is less reliable than the quoted 20% precision error, but that is another story. the study, however, does provide a rigorous test of the technology, does compare the performance of the three main pulse contour methods, albeit with now out of date flotrac software, and does add to the growing evidence that the pulse contour method is not the solution to providing reliable cardiac output monitoring at the bedside. | three pulse contour systems for monitoring cardiac output - lidco plus, picco plus and flotrac - were compared in postcardiac surgery patients. none of the three methods demonstrated good trending ability according to concordance analysis. pulse contour systems remain unreliable in the haemodynamically unstable patient. |
it must be reasons significant enough for me to argue for such a fundamental renovation (table 1). let me first very briefly review the minimal functionality of the dna code. for simplicity, i use a, u, g, and c for adenosine, uridine, guanine, and cytosine, respectively. the code of a dna sequence for producing proteins has only four basic variables : length, order, gc and ag (purine) contents (which are equivalent to what measured for au and uc contents), if we put aside the variability of nucleotide sequences over time for the moment. only the last two variables are relevant to the codon table of the canonical genetic code (hereby referred to as the table). unfortunately, the popular table is assembled merely for a concise and neat manifestation of the codon - to - aa context, and scrabbles clear messages that implicate physicochemical diversity of the amino acids and mutation sustainability of the dna - borne code. consequently, there is no reason to turn away new synthesis when the table is not really in its legitimate form and does not give correct illustrations even when similar displays may have been proposed for different reasoning (5). second, the new arrangement attempts to demonstrate the relationship between the informational and functional contents, concerning variability of gc and ag contents, thus more comprehensive and meaningful as we will see. third, though a minor point, it is also simpler to be understood and memorized since it makes no effort to distinguish the two purines and the two pyrimidines for the third codon position (cp3). i hope everyone who reads this article is able to memorize the renovated table precisely for his or her life time. first, i considered only two basic variables, gc and ag contents, although there have been many other hypotheses proposed over the past half century, such as resistance to frameshift errors in translation [6. it has been too much expectation for the codon - to - aa relationship analyses that have led to numerous hypotheses and debates (2., 9., 10. ; the relevant publications are so vast in number that i feel guilty to quote only a few. however, this article is not written as a comprehensive overview of the field but merely as an illustration of the alternative codon table). i do not have a slight doubt that the relatedness in the metabolism of amino acids and codon assignment does exist, but it is the genetic code that unites them in a unique way and brings them together to compose functional contents (encoding proteins). second, i can not agree more with early discoveries in nucleoside chemistry that a and t may be more ancient than g and c because c is too unstable to play a role in the origin of life 11., especially when c may not be essential for the constitution of early functional macromolecules (13). perhaps a transient role in the rna world for c is more than enough for it to deserve a place in the basic structure of dna ; or in a positive notion, its pairing with g makes dna more stable than the alternatives. nevertheless, this particular display divides the table into four parts ; each has its informational and biological sanities : the au - rich, the gc - rich, and the two intermediate - gc quarters (table 2a) that are actually not the same regarding to their first and second codon positions (cp1 and cp2). for the sake of convenience, let me call them the gcp1 and gcp2 quarters, referring to the difference of their gc contents at the codon position ; codons in the former have g or c at cp1 whereas those in the latter have g or c at cp2. the content - sensitivity of the au - rich and gc - rich quarters is very obvious if we ignore the third codon position 14., 15.. for instance, when the genomic gc content (ggc content) of an organism (say a bacterium) goes up, the former becomes underrepresented and the latter goes overrepresented because every a or t is subjected to be flipped over into g or c. nature then selects the individual who has made the right choice or eliminates the ones that made the wrong nucleotide flipping before the moment of truth under a given circumstance. the gcp1 and gcp2 quarters remain, by and large, neutral when ggc content varies in a statistic sense overall. although it remains in the same column as other two aromatic amino acids, tyrosine and phenylalanine, it is difficult to know how much it compensates the pressure on uay and uuy codon pairs when ggc increases, since a or u at cp2 and y at cp3 have to change simultaneously to turn uay and uuy into ugg. certainly, the conversion of uay to cay encoding another aromatic amino acid histidine in the gcp1 quarter is possible under pro - gc pressure. in addition, it is also predictable that gc2 (the gc content of cp2) is greater than gc1 (the gc content of cp1) since one of the codons in the gcp2 quarter is a stop codon, despite the fact that general codon usage biases may complicate the real statistics. the au - rich quarter possesses the most diversified set of amino acids in terms of their physicochemical properties, containing sixteen codons that encode for seven amino acids as well as two stop and one start signals. in comparison, the gcp1 and gcp2 quarters both encode six amino acids, whereas the gc - rich quarter encodes only four amino acids. the au - rich quarter is the only quarter that possesses codons for both start and stop signals, leaving us wondering if this quarter might represent the core diversity of the amino acids in building primordial proteins for the early life forms on earth. in addition to the legitimate concern about gc content variations, we can also see a division of the table into two halves (table 2b) according to the codon - aa variability between purine and pyrimidine (nucleotide transversions between r and y) at cp3 ; it also exhibits a clear separation of the amino acids with fourfold - degenerate codes from those with twofold - degenerate ones albeit the existence of two exceptions, aur and ugr. this separation further divides the two gc - insensitive quarters (the gcp1 and gcp2 quarters) into two portions. i would like to call these two halves as pro - diversity and pro - robustness (hereby referred to as the pd half and the pr half) based on their functional indications. first, three amino acids (serine, arginine, and leucine) that have six codons are partitioned precisely into each of the two halves although they are distributed among all quarters in a seemingly disordered way. this explicit distribution is obvious for the purpose of balancing the three amino acids, which are among the top abundance class by simple statistics such as the average or relative codon usage. an alternative way of explaining this distribution is to assume that these three amino acids were actually selected for the balance due to their roles in maintaining special physicochemical properties (such as catalytic residues) and unique functional domains (such as leucine zippers for transcription factors and the serine - arginine - rich domain for rna - binding proteins) of proteins. the balancing route involves all four quarters : (1) between the au - rich and gcp1 quarters (leucine) ; (2) between the gc - rich and gcp2 quarters (arginine) ; and (3) within the gcp2 quarter (serine) but across the sub - divided pd and pr halves (serine). as a result of this arrangement, the effect of gc - content increase is reduced through codon conversion rather than amino acid changes. this distribution suggests that the three stop codons (uaa, uag, and uga) are readily converted to the corresponding amino acids when gc content goes high, a potential to extend the length of encoded proteins at the 3-end. third, the two basic amino acids, arginine and lysine, appear robust against gc - content changes ; not only these two amino acids are partitioned sturdily into the pr and pd halves, but also the six arginine codons are divided into the gc - rich quarter and the gcp2 quarter between the two halves. as a contrast, the two acidic amino acids, glutamic acid and aspartic acid, appear taking a different approach they stay in the gcp1 quarter that is not sensitive to gc - content changes. it is also predictable that these two amino acids must be abundant in the proteins possessing them due to their neutrality against gc - content increase as well as their similarity in chemistry (acidic or negatively charged) and their positions in the table they are the most obvious pair resembling a fourfold - degenerate code when charges arose as the only concern in a polypeptide with complex structural constraints (i intend to classify this quadruplet and isoleucine as pseudo - quadruplet). another likely candidate for achieving high abundance is valine ; it has many neighboring amino acids (positioned in the table with perceptible rationales) that are either similar in hydrophobicity or equivalent in structural characteristics (such as physical dimensions). finally, staring at the table, one can easily understand why proline and its codons are sitting at the corner of the gc - rich quarter, and it may only be seriously called upon when gc content goes extremely high. the renovated table reveals that the codon arrangement is prioritized to reduce the impact of gc - content variations that fluctuate from 20% to 80% in eubacterial genomes where over 80% of the sequences are protein - coding. in other words, it seizes gc - content variations as the primary parameter. first, it divides the code into two portions, either sensitive (the au - rich and gc - rich quarters) or insensitive (the gcp1 and gcp2 quarters) to gc - content variations. second, it confines the high - gc codons as fourfold degenerate to further release the pressure from gc content increases at cp3. third, it keeps the physicochemically diversified amino acids in the au - rich quarter (pro - diversity) but leaves the amino acids of the gc - rich quarter to endure mutation pressure (pro - robustness) since they are less likely to be involved in catalytic activities as well as initiation and termination signals (with the exception of the amino acids with sixfold - degenerate codons, especially arginine and serine). fourth, the function of the gc - insensitive quarters is to protect (or generate in a sense for the origin of the genetic code) the majority of the abundant amino acids in addition to isoleucine in the au - rich and alanine in the gc - rich quarters. the ag content is the second to be concerned by the table since it fluctuates only 10% above or below the 50% mark among eubacterial genomes according to the chargaff s rule 16., 17.. it further divides the gcp1 and gcp2 quarters into purine - variation sensitive and insensitive divisions or the entire table into two halves. this division draws a clear line that separates the fourfold - degenerate code with the rest. in the low - diversity (referring to physicochemical properties of amino acids) or the high - robustness (referring to mutation tolerance) half, there are only five amino acids unique to it ; each has its subtleties in physicochemical characteristics unique to itself or shared with others. for instance, threonine shares the property of hydroxyl group with serine yet has a slightly extended hydrocarbonic chain. another example is valine (gun) ; it should be one of the most abundant amino acids since it is almost the most flexible amino acid of the quadruplet group, which is capable of replacing leucine (uur), methionine (aug), isoleucine (auy), and even phenylalanine (uuy) when gc content increases and if the mutation - altered protein backbone is embraced by hydrophobicity only. the third most striking feature in the table is the clustering of small amino acids aside from the relevance of gc and ag contents. there are several simple measures for the size or volume of the amino acids, such as residue volume (rv,) (18) and accessible surface area (asa,) that was calculated for the residue x in the tripeptide g - x - g (19). if we rank four smallest amino acids according to their size parameters, they are glycine (rv 60.1 and asa 75), alanine (rv 88.6 and asa 115), serine (rv 89.0 and asa 115), and cysteine (rv 108.5 and asa 135). the next in line is disputable, either aspartic acid (rv 111.1 and asa 150) or threonine (rv 116.1 and asa 140), depending on which measurement is preferred. clearly the most exchangeable pair in size is serine to alanine or vice versa when gc content varies. one essential feature of the table or the organization of the genetic code is its balancing power. although the table divides gc / ag sensitivity vs. insensitivity, amino acid diversity vs. simplicity, and mutation sensitivity vs. tolerance, it seems not favoring one over another. it is predictable that the balance may be severely distorted at least under certain conditions, such as when gc content goes to extremities. the purine content of eubacterial genomes can also go beyond the chargaff s rule (14), which puts pressure on protein sequence alterations. however, as the table indicates in its ag - sensitive half, some of the members in this half are there to play relief roles, too. aspartic acid and glutamic acid are in the same quadruplet, and when a negative charge is essential but not what the size or volume is, a purine to pyrimidine shift in cp3 becomes harmless. to a lesser extent, there are several similar cases in the pd half, including q / h (size), m / i (hydrophobicity), l / f (hydrophobicity), r / s (polar), w / c (polar), and k / n (polar). this is not farfetched since there has not been a case found possessing a mixed - up feature of hydrophobic vs. hydrophilic or polar vs. non - polar amino acids in the same quadruplet. sometimes, the obvious seems easier to be overlooked than the obscure. to sum up, in my thirty years or so scientific career, i have yet to find another topic that is so fundamental but so misunderstood as the genetic code (even ignoring discussion on the origin of the genetic code). it is critical for biology students to appreciate this rearrangement, to be able to memorize the distribution of the codons (amino acids) in the table, and to understand the functional indications of the codon positions and their relatedness deeply in order to avoid wasting time to read meaningless publications that have been trying to mystify the genetic code albeit mostly deemed unintentional. | the codon table for the canonical genetic code can be rearranged in such a way that the code is divided into four quarters and two halves according to the variability of their gc and purine contents, respectively. for prokaryotic genomes, when the genomic gc content increases, their amino acid contents tend to be restricted to the gc - rich quarter and the purine - content insensitive half, where all codons are fourfold degenerate and relatively mutation - tolerant. conversely, when the genomic gc content decreases, most of the codons retract to the au - rich quarter and the purine - content sensitive half ; most of the codons not only remain encoding physicochemically diversified amino acids but also vary when transversion (between purine and pyrimidine) happens. amino acids with sixfold - degenerate codons are distributed into all four quarters and across the two halves ; their fourfold - degenerate codons are all partitioned into the purine - insensitive half in favorite of robustness against mutations. the features manifested in the rearranged codon table explain most of the intrinsic relationship between protein coding sequences (the informational content) and amino acid compositions (the functional content). the renovated codon table is useful in predicting abundant amino acids and positioning the amino acids with related or distinct physicochemical properties. |
true radial artery aneurysms are extremely rare, with no documented prevalence in the medical literature. in 1966, the first recognition of this condition was introduced by thorrens, and since then some reports have been published. this paper describes a case of true radial artery aneurysm in a 65-year - old woman, and presents the clinical presentation, aetiologies, and diagnostic and therapeutic modalities. a 65-year - old woman presented to the outpatient clinic with a pulsatile mass at her right wrist. the patient denied history of trauma, surgeries or recurrent punctures, and there was no family history of aneurysms. upon physical examination, a mass of 2-by-3 cm found at the anatomical snuffbox area of the right hand, with no visible scars (fig. 1). later, ct angiography detected a local dilation at the distal part of the right radial artery (figs 2 and 3). complete body scan showed another aneurysm at the right common iliac artery measured 3-by-2.8 cm for which the patient was referred to a higher centre for possible endo - vascular intervention as it is not available in our hospital. figure 1:photo of the right hand of the patient shows a bulge at the snuffbox area. figure 2:transverse section of ct angiogram shows radial artery aneurysm at right hand (arrow). figure 3:reconstructed three - dimensional image shows radial artery saccular aneurysm (arrow). photo of the right hand of the patient shows a bulge at the snuffbox area. transverse section of ct angiogram shows radial artery aneurysm at right hand (arrow). reconstructed three - dimensional image shows radial artery saccular aneurysm (arrow). under local anaesthesia, the aneurysm site was incised. a saccular aneurysm of 2-by-1.5 cm appeared at the distal part of the radial artery. using vessel loops, a doppler examination was conducted and indicated positive signals over the thumb and digital arteries. later, the histopathology report showed a dilated arterial sac with a complete fibromuscular wall and an organized thrombus attached to its lumen (fig. 5). figure 4:the aneurysm with the radial artery controlled proximally and distally. figure 5:microscopic view of the aneurysmal wall shows the muscular layer. upper extremity arterial aneurysms are rare in surgical practice. ogeng'o. found that the prevalence of radial artery aneurysms is 2.9% of all aneurysms affect the upper limbs. many cases have been reported after thorrens, the majority reported traumatic pseudo - aneurysms and only few authors reported cases of true idiopathic aneurysms. a medline search was conducted using the terms radial artery and aneurysm and radial artery and pseudoaneurysm, and returned 68 and 46 articles, respectively, published until may 2013. of these, radial artery cannulation, bone fractures, occupational injuries and traumas were the commonly reported causes. up to 15 other cases were reported as aneurysms induced by systemic pathologies. among all 102 reported cases, only 8 cases were reported as idiopathic true radial artery aneurysms. clinically, patients usually present with pulsatile swelling with or without pain which is usually due to the compression of the surrounding structures. the aneurysm has the potential to cause ischaemia due to laminar emboli or thrombus formation. moreover, traumatic rupture could occur due to the vulnerable location nonetheless ; spontaneous rupture is always a possibility. the diagnosis is initially clinical, but many imaging modalities could help in the diagnosis and in the management of such condition. duplex ultrasonography can be used first to differentiate the aneurysm from other masses with the help of colour doppler ; it is inexpensive and carries no risk to patients. ct angiography has the ability to delineate the aneurysms clearly, and it is ideal to scan the whole body to exclude the other aneurysms existence, although it carries the risk of contrast - induced nephropathy and is expensive. magnetic resonance angiography (mra) is another choice, but its higher cost makes it unpopular. in fact, the best treatment for radial artery aneurysms is still controversial ; however, the surgeon 's decision can be guided by taking some factors into consideration. the critical question is : is it the radial or the ulnar artery that carries the majority of blood supply to the hand ? currently there is no consensus about which non - invasive modality should be used to evaluate the circulation of the hand pre - operatively. many options are available with variable sensitivity and specificity ; for instance, allen 's test, modified allen 's test, digital plethysmography, digital doppler waveforms, and pressures and duplex ultrasonography. more reliable but invasive choices are available to assess the patency of the arteries and the development of the arterial arches, including ct angiography or conventional angiography. patient symptoms and the presence of thrombosis, distal emboli or infections are also important factors to determine the mode of management. technically, the management include the following choices : careful observation ; in case of small asymptomatic aneurysms, arterial ligation and aneurysm excision or arterial reconstruction ; whether by end end anastomosis or by vein graft in the case of aneurysmal dominant artery. in our patient, the decision to excise the aneurysm and ligate the artery was based on the results of ct angiography, modified allen 's test that clarified ulnar dominancy and the positive doppler signals over the dorsal digital artery of the thumb after radial artery clamping intra - operatively. | true aneurysms of hand arteries are rare. i present a case of a true saccular aneurysm of the distal radial artery in a 65-year - old woman with no history of trauma. the ct angiography, intraoperative features, operative procedure, histopathological examination and literature review are presented and discussed. |
monocondylar tibia plateau fractures with non - comminuted fragments can be treated using percutaneous screws. currently indirect methods of reduction are used and thus the technique is limited to fragments with less than 5 mm depression. the first author has designed a device for direct elevation and reduction of the fragments thus potentially expanding the indications of percutaneous screws to fragments with > 5 mm depression a total of ten cases were treated by this method of percutaneous elevation of the depressed fractures of lateral condyles of the tibia using this device. the inner piston of the device in slowly hammered inside thus elevating the depressed fragment. the new device is able to elevate unicondylar tibia plateau fragments with no subsidence or loss of fixation in our series. a longer follow up in a larger sample will be needed to establish the technique. the tibial plateau fractures are still a challenging problem and demand an aggressive management as any other intraarticular fractures of the joints. before the advent of the recent advances conservative management was the treatment of choice resulting in joint stiffness which was very crippling to the patient. the thorough understanding of the classification the tibial plateau fractures based on the recent investigations, has opened the gates for better management. the amount of depression and the displacement of the condylar fractures, articular incongruity can be well assessed nowadays. schatzker classification is the most accepted classification currently and type i to iv fractures are associated with angulated or depressed fractures of either of the one condyle. in cases with large sinlge peripheral fractures most papers describe indirect method of reduction of these fragments via ligamentotaxis and thus limit themselves to depression 5 mm. the present paper discusses the usefulness of the device in elevation of the depressed condyles with a small window (very minimal incision). device : the device is designed by first author [vsr ] indigenously with 316 ss alloy. the diameter of outer sleeve is 11 mm and the wall thickness of the sleeve is 1 mm. the diameter of the solid piston is 10 mm and it freely moves to and fro in the outer sleeve (fig. the serrated edges of the sleeve help in insertion in the metaphyseal area surgical steps : ten male patients (age between 25 - 40 years) were operated using this device. first the direction elevation was assessed by a guide wire passed through a drill hole on the antero medial aspect of the upper one fourth of the tibial metaphysis (fig. a bone window sufficient to accommodate the outer sleeve is made round the guide wire. then the piston was pushed into the sleeve and the piston was tapped towards the depressed fracture carrying a cylindrical cancellous plug of the bone to elevate the fracture condyle till plateau is congruous which was checked under the c - arm image in both views (fig. next again under c - arm control a guide was passed perpendicular to the fracture line of the condyle keeping the piston in the intramedulary canal. a cancellous screw was threaded over the guide wire to fix the fracture (fig. we had used two screws in majority of the cases with one screw used in one case, depending on size of the fragment. we were able to achieve good articular reduction in all our cases by use of this technique. weight bearing was allowed after the radiological union was present i.e after 8 weeks. in this buttressing with a plate was not needed as we felt the fixation achieve was stable enough and also weight bearing was delayed allowing for healing of the fracture. early results are encouraging with all cases achieving radiological union and good knee range of motion. there were no cases of loss of reduction or any other complications although a longer and more detailed prospective follow up will be required to establish the potential clinical importance of the device after elevation of the fragment another guidewire is passed through the fragment over which a 6 mm cannulated cancellous screw is passed percutaneously - d. percutaneous screw fixation in cases on monocondylar tibia fractures will prevent the morbidity associated with open procedure and is less expensive too. a lot of case series describe percutaneous screw fixation however these are based on indirect reduction techniques and are limited to depression less than 5 mm [1 - 6 ]. we felt a device which can directly help in elevating the fragment to achieve intraarticular reduction will definitely expand the indication of this minimally invasive technique. the solid inner rod compresses the metaphyseal cancellous bone thus compacting it below the subchondral area. we found this technique to be useful in 10 of our patients to achieve reduction. however most of our patients were young and were operated within a day or two of injury, thus usefulness of this device in older injuries and older patients (with osteoporosis) is yet to be defined. a long term follow up, a larger size sample and report of reproducability of this device by our peers will be essential to confirm the potential usefullness of this device. | introduction : monocondylar tibia plateau fractures with non - comminuted fragments can be treated using percutaneous screws. currently indirect methods of reduction are used and thus the technique is limited to fragments with less than 5 mm depression. the first author has designed a device for direct elevation and reduction of the fragments thus potentially expanding the indications of percutaneous screws to fragments with > 5 mm depressiontechnical note : a total of ten cases were treated by this method of percutaneous elevation of the depressed fractures of lateral condyles of the tibia using this device. device was inserted through a bony window on the anteromedial surface of tibia. the inner piston of the device in slowly hammered inside thus elevating the depressed fragment. elevation of fragment could be achieved in all the cases. the fractures were fixed with cancellous screws applied percutaneously. there were no cases with loss of fixation or subsidence of the fragment. all cases achieved radiological union and have good knee function at follow upconclusion : the new device is able to elevate unicondylar tibia plateau fragments with no subsidence or loss of fixation in our series. a longer follow up in a larger sample will be needed to establish the technique. |
microbial communities of acidic wetlands are responsible for emissions of the potent greenhouse gases methane (ch4), and nitrous oxide (n2o ; conrad, 1996 ; whalen, 2005 ; denman., 2007). the largest single global source of atmospheric ch4 (100237 gt year) are acidic wetlands, such as peat bogs and fens that cover 3.5% of the terrestrial surface, but store about 30% of global carbon of terrestrial ecosystems (gore, 1983 ; denman., 2007). largest sources of atmospheric n2o are soils under natural vegetation and agricultural use ; nonetheless, certain acidic wetlands that have a high nitrogen content were recently identified as significant sources of n2o displaying n2o emissions in the range of those observed for agricultural soils (denman. conservative estimates suggest that 0.6% of the global annual emission of n2o might be attributed to such acidic wetlands (repo., 2009). acidic wetlands are covered by water - adapted vascular plants, and mosses of the genus sphagnum (gorham, 1991). microbes that produce ch4 are methanogenic archaea, and those that are the main source of n2o are denitrifiers in anoxic habitats like wetlands (conrad, 1996 ; ferry, 1999 ; drake., 2009). ch4 produced by methanogens is further oxidized by aerobic methanotrophs, which thrive as a significant part of wetland microbial communities and mitigate the net ch4 flux into the atmosphere (hanson and hanson, 1996 ; shannon., 1996 ; whalen, 2005 ; knorr., 2008 ; hornibrook., 2009) atmospheric oxygen may penetrate soil due to water table draw downs, and gas transport through the aerenchyma of vascular plants into the rhizosphere (moog and bruggemann, 1998 ; kettunen., 1999 ; mainiero and kazda, 2005 ; paul., 2006). acidic wetlands may temporarily turn into sinks of atmospheric ch4, or at least have the potential to consume atmospheric ch4 (1.75 ppmv ; table 1 ; whalen and reeburgh, 2000 ; jauhiainen., 2005 ; elberling., 2011), a fact that is currently underappreciated, and poorly understood on the level of microbial communities. acidic wetlands exhibiting consumption of atmospheric ch4 or n2o, and associated methanotroph and denitrifier communities if such data were available. calculated based on reported first order rate constant (i.e., 0.03 h gsoil dw) at 1.8 ppmv (assumption : water content 50%, 1.8 ppmv = 2.5 nm ; thus, dissolved ch4 concentration is 5 pmol gsoil dw). this rates are calculated from first order rate constants of ch4 consumption (i.e., based on km [43 nm ; or 3.6 nmol gsoil wet weight ] and vmax [38.5 nmol gsoil wet weight ] values as reported in the reference) at a headspace concentration of 1.8 ppmv. association of denitrifiers with n2o production in nitrogen - rich acidic wetlands is indicated by process - orientated studies of water - logged acidic soils, and denitrification is suggested as the primary n2o producing process in such systems where the water filled pore space exceeds 70% (davidson, 1991). denitrifiers catalyze the sequential reduction of n - oxides to nitrous oxide (n2o) and/or dinitrogen (n2) via the sequential action of nitrate, nitrite, nitric oxide, and nitrous oxide reductases (zumft, 1997). subunits that contain the catalytic center are encoded by narg / napa, nirk / nirs, norb, and nosz. dissimilatory reduction of nitrate via nitrite to ammonium (dnra) might produce n2o under oxygen limited conditions via the unspecific interaction of nitrite with nitrate reductase (smith and zimmermann, 1981 ; smith, 1983). however, dnra potentials are low in acidic wetland soils, and free nitrite is virtually absent from such soils, suggesting that dnra is negligible with regards to n2o production (anderson and leine, 1986 ; bowden, 1987). significant products of chemodenitrification are no and no2 rather than n2o (van cleemput, 1998 ; kappelmeyer., 2003 ; kresovic., 2009) n2o is also produced as a by - product during the aerobic conversion of ammonia to nitrate by nitrifiers, but nitrification is the primary source of n2o in oxic rather than water - logged soils (davidson, 1991 ; conrad, 1996). despite the importance of denitrifiers for n2o production in water - logged soils and the wealth of information on denitrifiers of agricultural and ph - neutral upland soils, studies addressing acid - tolerant denitrifiers in acidic wetlands are just emerging and under - represented in current literature. evidence is accumulating that soils including acidic wetlands can act as temporary sinks for n2o (inubushi., 2003 ; hadi., 2005 ; chapuis - lardy., 2007 indeed, negative fluxes of up to 1.7 mol n2o m h were observed in situ for acidic wetlands (table 1). thus, the review intents to delineate the current understanding of microbial communities in acidic wetlands for ch4 and n2o consumption and to highlight research needs. ch4 fluxes of acidic wetlands are highly variable due to non - linear interactions of environmental factors that control methanogenesis, methanotrophy, and ch4 gas transport (whalen, 2005 ; spahni., 2011). one reason of high spatial and temporal variability of ch4 exchange with the atmosphere might be a mitigation of net flux by consumption of atmospheric ch4 (wieczorek., 2011). hot spots of activity of methanotrophs in acidic wetlands are anoxic oxic interfaces, where ch4 and oxygen gradients overlap (sundh., 1995 ; kettunen., 1999 thus changes in oxygen availability alter both ch4 consumption, and production, and hence, reduce or increase net flux of ch4 from soil into the atmosphere (kettunen., 1999 ; total cell numbers of methanotrophs of acidic wetlands range from 10 to 10 cells per gram of wet weight (sundh., 1995 ; dedysh., 2001, 2003 ; dedysh, 2002, 2009 ; belova., 2011). methanotrophic pure cultures have primarily been isolated from sphagnum - covered wetlands, and are acid - tolerant strains of methylocystis (methylocystaceae), methylocella, and methylocapsa (both beijerinckiaceae ; dedysh., 2001, 2003 ; dedysh, 2002, 2009 ; kip., methylocella species, and some species of methylocystis and methylocapsa utilize also simple multicarbon compounds, such as acetate (dedysh., 2005 ; theisen., 2005 ; dunfield., 2010 ; belova., fluctuations of soil - internal methanogenesis may be caused by varying exudation of plants and redox conditions due to water table changes that can be consequences of drought periods, or heavy rainfall (knorr., 2008 ; knorr and blodau, 2009, dorodnikov., 2011). methylocystis strain h2s apparently represents a key methanotroph in acidic wetlands (belova., 2011 ; strain h2s - related 16s rrna genes ubiquitously occur in northern wetlands, and contribute with 1858% (i.e., 0.4 10 to 3.4 10 cells g of wet weight) to the alphaproteobacterial methanotrophs in such wetlands (belova., uncultivated species that are phylogenetically related to methylocystis, and methylocapsa are associated with hyaline cells of submerged mosses of sphagnum. these sphagnum methanotroph associations have been found in various northern wetlands (kip., 2010). methanotrophs apparently contribute up to 30% to carbon assimilation of the moss (raghoebarsing. the association is, based on current observations, not specific since different methanotroph - free sphagnum species can be colonized by methanotrophs that were provided from the same sphagnum individual (larmola., 2010). the physiological basis of the interaction between methanotroph and moss has not been fully resolved. wetland methanotroph communities are usually dominated by alphaproteobacteria, but gammaproteobacterial methanotrophs may also be present (morris., 2002 ; chen. some of them (methylomonas-, methylosoma - related strains) have been isolated, which represent the first acid - tolerant members of the methylococcaceae (kip., 2011). all cultured methanotrophs of acidic wetlands are acid - tolerant and have growth optima below ph6 (dedysh, 2009 ; kip., 2011). most information on the identities and physiologies of methanotrophs of acidic wetlands are derived from sphagnum - associated microbial communities, but there is a lack of information on vascular plant - associated methanotrophs in acidic wetlands. acidic wetlands may temporally turn into net sinks of atmospheric ch4, which has been documented in various studies, or have the capability to utilize atmospheric ch4 concentrations (table 1 ; figure 1 ; dedysh and panikov, 1997 ; kettunen., 1999 ; whalen and reeburgh, 2000 ; jauhiainen., 2005 ; elberling., 2011 ; wieczorek., many wetland sites have annual emission rates of less than 3.8 mol ch4 ha year (dalal and allen, 2008) indicating not necessarily only low ch4 production, but also a certain proportion of consumption of atmospheric ch4 over the year. proposed model of microbes that are responsible of atmospheric sink function of ch4 and n2o in natural wetlands. the quantitative contribution to global net fluxes of ch4 and n2o into the atmosphere has not been evaluated in acidic wetlands. (a) acidic wetland covered by sphagnum plants with low nitrogen input and mineralization rates. white pathway : plant - derived organic matter is degraded by microbial fermentation, acetogenesis, and methanogenesis to ch4 that is transported to oxygen - saturated zones close to the surface. the thickness of the oxygen - saturated layer is dependent of water table level (white dotted line). methanotrophs (such as methylocystyceae, beijerinkiaceae, but as well methylococcaceae) consume up to 90% of methanogenic ch4. methanotrophs convert ch4 to carbon dioxide (co2) which is released into the atmosphere. yellow pathway : methylocystis species likely consume atmospheric ch4 when ch4 supply from anoxic zones is limited. (b) natural wetland with high nitrogen input and mineralization rates (e.g., minerotrophic fens, palsa peats). white pathway : in nitrogen - rich acidic wetlands (e.g., palsa peats) a part of anaerobic organic matter degradation intermediates are consumed by denitrifiers that reduce no3- to n2o and n2. ammonia - oxidizing bacteria (aob) are known to produce small amounts of n2o during oxidation of ammonia (schmidt., 2004 ; braker and conrad, 2011). yellow pathway : under as - yet unresolved environmental conditions atmospheric n2o may be further reduced to n2 by to date not cultured denitrifiers that use electrons from organic matter. a very limited number of studies analyzed the composition of methanotroph communities of acidic wetlands, and measured the potential of the respective wetland to consume atmospheric ch4 (table 1). methylocystis species that were frequently detected in acidic wetlands are closely related to the solely known methanotroph strains that are capable of consumption of atmospheric ch4, i.e., strains lr1, sc2, and dwt (dunfield., 1999, 2002 ; kolb., 2005 ; baani and liesack, 2008 ; dedysh, 2009 ; wieczorek., 2011). nonetheless, pmoa2 genes (that encode for the hydroxylase subunit of a high affinity ch4 mono - oxygenase) that would indicate the capability of consumption of atmospheric ch4 (dunfield., 2002 ; yimga., 2003 ; ricke., 2004 ; baani and liesack, 2008) have only been detected at low relative abundances (< 5% ; wieczorek., 2011). to warrant consumption of atmospheric ch4 in wetlands a small fraction (about 10 cells per gram dry weight in forest soils that consume atmospheric ch4 ; kolb. 2010) of the total cell number of present methanotrophs (about 10 cells per gram dry weight) need presumably be active to allow for consumption of atmospheric ch4 at rates that were observed in acidic wetland sites. the major proportion of detectable pmoa (encodes the beta - subunit of a low affinity membrane bound ch4 mono - oxygenase) and mmox (encodes the hydroxylase subunit of a low affinity cytoplasmic bound ch4 mono - oxygenase) genes in an acidic wetland soil that exhibited the capability of consumption of atmospheric levels of ch4 (i.e., 82 and 64%, respectively), affiliated with genes of methylocystis (wieczorek., 2011). the abundant methylocystis strain h2s harbors as well pmoa2 indicating that this methanotroph may consume atmospheric ch4 (dedysh, personal communication). thus, methylocystis species of acidic wetlands likely are capable of atmospheric ch4 consumption (figure 1), and may have the advantage to survive more likely periods of ch4 deficiency, may be periodically the case in minerotrophic fens, and at oxygen - saturated surface - near soil layers. (ettwig., 2010) have not been detected in acidic wetlands. in summary, the role of other methanotrophs in acidic wetlands (i.e., beijerinckiaceae, and methylococcaceae) in consumption of atmospheric ch4 is not fully unresolved, but not very likely based on their low affinities for ch4. it is not likely that m. oxyfera is involved in n2o cycling since it lacks nitric oxide reductase. one of the most remarkable features of denitrifiers is their capacity to produce and consume n2o (table 1 ; figure 1 ; zumft, 1997). such organisms are widely distributed in various environments and highly diverse (e.g., zumft, 1997 ; braker and conrad, 2011). not all denitrifiers known to date are capable of n2o consumption (zumft and kroneck, 2007). however, n2o is a common intermediate during denitrification and serves as sole electron acceptor for supporting growth of many denitrifiers (zumft, 1997 ; strohm., 2007). dna based stable isotope probing with c - labeled succinate as electron donor and n2o as electron acceptor and cultivation - based studies demonstrated growth of putative denitrifiers by n2o reduction in rice field soil (ishii., 2011). these findings are in line with a g0 of n2o reduction to n2 that approximates 340 kj mol under standard conditions, indicating a highly exergonic process (zumft and kroneck, 2007). thus, it might not be surprising that n2o consumption by soil communities is a more common phenomenon than previously thought (table 1 ; reviewed in holtan - hartwig. n2o reductases of denitrifiers catalyze the efficient reduction of n2o to n2 and are copper - dependent metallo - enzymes that exhibit km values in the lower micromolar range for n2o, highlighting the potential of denitrifiers to consume low concentrations of n2o (zumft, 1997). abiotic conversion of n2o at ambient temperatures might occur with (reduced) transition - metal complexes (which occur in the active site of n2o converting enzymes) and metal amides (banks. metallo - enzymes like carbon monoxide dehydrogenase and cobalamin - dependent methionine synthase are also capable of reducing n2o to n2, while nitrogenase converts n2o to nh3 ; bacterial nitrite cytochrome c reductase transforms n2o to an unknown product (jensen and burris, 1986 ; bannerjee and matthews, 1990 ; lu and ragsdale, 1991 ; drummond and matthews, 1994 ; stach., 2000). such enzymes are hosted by diverse organisms including non - denitrifiers (see references in zumft, 1997 ; zumft and kroneck, 2007). however, the conversion of n2o by these aforementioned enzymes is regarded as a non - physiological reaction. low km values and high specific activities for n2o (as were demonstrated for n2o reductases of denitrifiers) have not been demonstrated for such enzymes, suggesting a minor role, if any, for the consumption of atmospheric n2o concentrations (319 ppb, equivalent to app. 8 nmol n2o per liter soil solution ; conrad, 1996) in soils (zumft, 1997 ; stach., 2000 ; zumft and kroneck, 2007). in this context, dissimilatory reducers of nitrate producing ammonia of the enterobacteriaceae that were shown to consume n2o in the laboratory displayed a km value of 3 mm for n2o, likewise suggesting that the n2o reduction is a non - physiological reaction and probably of minor importance in situ (kaldorf. moreover, assimilatory reduction of n2o that might theoretically proceed via nitrogenase action was not detected in soils (vieten., 2008). thus, denitrifiers hosting n2o reductases deserve primary attention in the context of n2o consumption in soils. denitrification rates and the ratio of n2o to total nitrogen gas products are regulated by oxygen availability, ph, temperature, carbon to nitrogen ratio, the availability of substrates, and electron acceptors, as well as by the denitrifier community composition (van cleemput, 1998 ; drsch., 2011). anoxia (as indicated by a water filled pore space of greater than 60%), a carbon to nitrogen ratio greater than 30, and ph - neutral conditions favor complete denitrification to n2 in soils including acidic wetlands (conrad, 1995, 1996 ; klemedtsson., 2005 ; cuhel., 2010 ; braker and conrad, 2011). a ph value below 5 is often encountered in peatlands, and is hypothesized to impair n2o reduction and to increase the product ratio of n2o to n2 (simek and cooper, 2002 ; cuhel., 2010). however, acidic wetlands host acid - tolerant denitrifiers capable of n2o reduction and complete denitrification (palmer., 2010, 2011). moreover, evidence of active denitrification - associated n2o production and consumption, (including consumption of atmospheric n2o concentrations) was obtained by compound specific stable isotope analyses of n2o in one acidic wetland (goldberg., 2008, 2010). in that specific wetland, n values indicated that n2o produced in deep soil layers was partially consumed upon its diffusion to the soil surface (goldberg., 2008, 2010), suggesting that denitrifiers might contribute to the mitigation of n2o emission from acidic wetlands. denitrifiers that exhibit the genetic potential to consume n2o were detected in acidic wetlands by the analysis of nosz genes. detected nosz genes in acidic wetlands mostly affiliated with nosz from uncultured soil bacteria or were only distantly related to known genes, suggesting a wealth of uncultured denitrifier diversity in acidic wetlands (palmer. phylogenies of nosz and 16s rrna genes from the same organisms are basically congruent (jones., 2008 ; palmer., 2009), allowing to speculate on the identity of organisms hosting the detected nosz. thus, putative n2o reducers in acidic wetlands include alphaproteobacteria (azospirillum, brady-, and mesorhizobium), betaproteobacteria (achromobacter, ralstonia), and gammaproteobacteria (pseudomonas). however, it remains to be determined whether the detected n2o reductase genes were expressed, i.e., the detected organisms reduce n2o in situ (figure 1). analyses of other genes associated with denitrification corroborate that acidic wetlands harbor diverse and new denitrifiers (palmer., 2010, 2011). however, given the low number of studies addressing n2o - consuming denitrifier communities in acidic wetlands, and the selectivity of pcr - based gene marker analyses, the present studies have to be regarded as providing a minimal estimate of denitrifier diversity capable of n2o consumption (throback., 2004 ; green., 2010 ; heylen., 2011 ; jones., 2011). the fact that high affinity respiratory n2o reduction occurs in non - denitrifying organisms that reduce nitrate but lack nitrite reductase activity, and that nitrifiers were shown to have the capability to consume n2o and produce n2 further complicates matters (yoshinari, 1980 ; mcewan., 1985 ; zumft, 1997 ; schmidt., 2004). nevertheless, the relevance of n2o consumption for mitigation of n2o emissions, and eventually a temporary sink function of acidic wetlands for n2o is emerging, although the physiology and taxonomic identity of microbial catalysts have not been sufficiently resolved. furthermore, the regulation of n2o reduction in situ and on cellular level, and thus the potential of the soil to reduce n2o to n2, and the diffusivity of n2o within the soil profile will impact the sink functions of wetland soils for n2o but are likewise only poorly resolved. few studies addressed the role of methanotrophs and denitrifiers in consumption of atmospheric ch4 and n2o in acidic wetlands. potential consumption activities have been measured in laboratory - scale experiments, and first evidence for denitrification - associated n2o consumption in situ is available. systematic in situ flux measurements combined with measurements of environmental parameters, consumption potentials, stable isotope signatures of carbon and nitrogen in ch4 and n2o pools, and community analyses are needed to improve our understanding of environmental factors that trigger ch4 and n2o consumption in acidic wetland soils. the authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. | acidic wetlands are global sources of the atmospheric greenhouse gases methane (ch4), and nitrous oxide (n2o). consumption of both atmospheric gases has been observed in various acidic wetlands, but information on the microbial mechanisms underlying these phenomena is scarce. a substantial amount of ch4 is consumed in sub soil by aerobic methanotrophs at anoxic oxic interfaces (e.g., tissues of sphagnum mosses, rhizosphere of vascular plant roots). methylocystis - related species are likely candidates that are involved in the consumption of atmospheric ch4 in acidic wetlands. oxygen availability regulates the activity of methanotrophs of acidic wetlands. other parameters impacting on the methanotroph - mediated ch4 consumption have not been systematically evaluated. n2o is produced and consumed by microbial denitrification, thus rendering acidic wetlands as temporary sources or sinks for n2o. denitrifier communities in such ecosystems are diverse, and largely uncultured and/or new, and environmental factors that control their consumption activity are unresolved. analyses of the composition of n2o reductase genes in acidic wetlands suggest that acid - tolerant proteobacteria have the potential to mediate n2o consumption in such soils. thus, the fragmented current state of knowledge raises open questions concerning methanotrophs and denitrifiers that consume atmospheric ch4 and n2o in acidic wetlands. |
both anomalous origin of the right coronary artery (rca) from the left coronary cusp or congenital long qt syndrome (lqts) are an important cause of sudden cardiac death, especially in young and healthy individuals. however, sudden cardiac death in a patient with these two disease entities has not yet been reported. here, we report the case of a young female with repeated aborted cardiac death accompanied by anomalous origin of the rca and congenital lqts. a 15-year - old female with a prior history of aborted cardiac death and surgical correction of anomalous origin of the rca was referred to the cardiology department due to repeated aborted sudden cardiac death after physical exertion with boxing. 1). biphasic 200 joules defibrillation restored the heart to sinus rhythm and cardiopulmonary function recovered without neurologic sequelae. two years prior to this event, she experienced chest discomfort followed by aborted sudden cardiac death after heavy exercise for the first time. she was successfully resuscitated after basic life support maneuvers and fully recovered with hypothermic treatment after being admitted to the emergency department. her family history of structural heart disease, syncope or sudden cardiac death was unremarkable. cardiac computed tomography revealed anomalous origin of the rca from the left coronary cusp coursing between the pulmonary artery and the aorta (fig. her follow - up ecgs after stabilization showed a sinus rhythm with an inverted t wave and a prolonged qt interval which was suggestive of congenital lqts (fig. she was not taking any medications which can prolong the qt interval and laboratory findings did not show electrolyte abnormalities. but this finding was overlooked and anomalous origin of the rca was provisionally considered as the cause of the aborted cardiac arrest. she underwent surgery to re - implant the anomalous rca from the left to the right sinus of valsalva. after receiving surgical correction of anomalous origin of the rca, she had been doing well before the second event of aborted cardiac death developed. coronary angiogram with a provocation test using ergonovine was done after the second event, and it revealed no significant abnormalities and the re - implantation site of the rca ostium was intact. an electrophysiologic study was performed to rule out possible causes of other arrhythmias leading to cardiac arrest. however no other arrhythmia was induced and also polylmorphic ventricular tachycardia was not inducible with programmed stimulation. the ecg after restoring the heart to sinus rhythm showed still significant prolongation of the qt interval, resulting in the diagnosis of lqts, probably type i, regarding her clinical presentation, even though the ecg pattern showed a prolonged qt interval and a notched t wave suggesting lqts type 2. medication with a -blocker (atenolol) was started and the dose was titrated up to 1.3 mg / kg (50 mg bid, regarding her body weight ; 78 kg). a follow - up exercise tolerance test revealed blunting of the heart rate response during maximal exertion and she was instructed to avoid heavy exercise. she remained free from ventricular arrhythmias while she was on a -blocker medication during the follow - up of more than 6 months. her serial follow - up ecgs showed significant qtc prolongation of > 500 ms consistently. we report the case of a young female with repeated cardiac arrest accompanied by anomalous origin of the rca and congenital lqts. surgical correction of the coronary anomaly was performed and the diagnosis of lqts was made after the second episode of aborted cardiac death. congenital lqts is a genetic disorder characterized by a prolonged qt interval and polymorphic ventricular tachycardia. prolongation of the repolarization phase acts as a primary step for the generation of early after depolarizations (eads) and prolonged repolarization is associated with increased spatial dispersion of repolarization in the lqts. the focal ead - induced triggered beats can infringe on the underlying substrate of inhomogeneous repolarization to initiate polymorphic reentrant ventricular arrhythmia.1) the features of qt prolongation on ecg can be difficult to recognize or sometimes overlooked. although genetic testing may provide additional information, the rationale is often debatable and the diagnosis of lqts remains a challenge. the schwartz scoring system is widely used in clinical practice and the high probability of a clinical diagnosis gives the yield of positive genetic testing in 72%.2) we could not confirm the genotype in this patient ; however, the scoring system was suggestive of a high probability of lqts. coronary artery anomalies of ectopic rca originating from the left sinus were found in approximately 0.92% in a recent prospective study.3) anomalous origin of the rca from the left coronary cusp which courses between the pulmonary artery and aorta can cause a malignant arrhythmia due to the potential for rca ischemia, particularly during exertion or stress. physical exertion can precipitate a ventricular arrhythmia in both conditions, even though the mechanisms are different. also, it is possible that both conditions can interact with each other to increase the susceptibility to develop a ventricular arrhythmia. recent studies have shown that only a long qt interval is not sufficient to provoke polymorphic ventricular tachycardia.4) heterogeneity of repolarization throughout the transmural regions of the ventricle, which results in transmural dispersion of repolarization, is a marker of electrical instability. this enhanced transmural dispersion of repolarization allows for the propagation of multiple waves of reentry, which is responsible for polymorphic ventricular tachycardia by serving as a functional underlying reentrant substrate.5) as previously reported, the qt interval can be prolonged during the early post - infarction period.6) furthermore, the qt interval was significantly more prolonged in patients with extensive transmural infarction.7) thus, significant myocardial ischemia due to extrinsic compression or spasm of the rca might exacerbate transmural dispersion of repolarization and play a role in triggering ventricular arrhythmia during the first episode of aborted sudden cardiac death in our patient with qt prolongation. however, lqts might be solely responsible for the second episode of polymorphic ventricular tachycardia because she received definite treatment for the coronary anomaly. implantation of a defibrillator was considered because of repeated aborted cardiac death ; however, treatment for lqts had not been attempted before. -blocker is relatively effective in congenital lqts type i ; therefore, a defibrillator was not placed in the patient and sympathetic denervation was not performed in this patient, who was carefully monitored instead. in conclusion, both anomalous origin of the rca from the left coronary cusp and lqts can coexist and interact to induce a ventricular arrhythmia. we should not overlook qt prolongation even in a patient with a diagnosis of anomalous origin of the rca from the left coronary cusp. | a 15-year - old female with a prior history of aborted cardiac death and surgical correction of anomalous origin of the right coronary artery (rca) presented with polymorphic ventricular tachycardia. her electrocardiogram after defibrillation was suggestive of congenital long qt syndrome (lqts). the patient was treated with a -blocker and remained free from ventricular arrhythmia during the follow - up of more than 6 months. here, we present the case of a young female with repeated aborted cardiac death accompanied by anomalous origin of the rca and congenital lqts for the first time. |
recent studies of marine organisms have focused on their potential applications, particularly in the treatment of human diseases. several marine natural products are currently in pre - clinical and clinical evaluation, others show promising biological activities. one of them, sarcophytol a (1), an oxygenated cembrane - type diterpenoid isolated from the soft coral sarcophyton glaucum has been shown to inhibit the development of large bowel cancer in female rats, as well as to suppress carcinogenesis in liver, breast, thymus and skin in mice. this marine natural product has shown significant inhibitory activity against various classes of tumor promoters. sarcophytol a inhibits tumor promotion induced by both known tumor promoters okadaic acid and 12-o - tetradecanoylphorbol- 13-acetate (tpa). it was also found that sarcophytol a inhibits hydrogen peroxide formation by tpa activated human polymorphonuclear leukocytes. treatment with sarcophytol a during both inititation and tumor promotion was more effective than treatment in the tumor promotion stage only. because of these activities, sarcophytol a and its analogs, have become very promising cancer chemopreventive agents. due to its cancer preventive activity a major obstacle in clinical studies of sarcophytol a, however, is supply of the material. our research focuses on sarcophine (2) as a source of potential pharmaceutical agents. in contrast with sarcophytol a (1), sarcophine (2) is one of the most abundant cembranolides ever known. it is the major metabolite of soft coral sarcophyton glaucum, and may be isolated in 13 % yield (of dry weight) from the crude extracts. sarcophine is a stable crystalline compound and can be easily modified to derivatives with high chemopreventive activity. in our recent work, we described the semisynthesis of several sarcophine derivatives with and without an unsaturated -lactone ring. we observed that derivatives with 1,2-propanediol moiety have much better chemopreventive activity than those with an intact lactone ring. based on this observation we have built a hypothesis that the 1,2-propanediol moiety in cembranoid skeleton is responsible for enhancing the chemopreventive activity to an extent superior to sarcophytol a, the standard used in our assays. a comparison of biological activities for analogous compounds (36) with and without lactone ring proved this hypothesis (table 1). the yields of the products obtained varied from 1223%, and it became obvious that there is a need to prepare a lead compound that can be produced in a good yield and retain good chemopreventive activity to be used to further modify the structure of this class of compounds for sar studies. this compound is a simple representative of this class of cembranoids with a 1,2-propanediol moiety instead of the lactone ring, and without any other substitutions. in our recent publication, compound 7 was obtained in a small yield (13%) during the reaction of the reduced sarcophine (8) with selenium dioxide at room temperature, together with the main reaction products which were the 7,8-epoxy-1,3,11-cembratriene-13r()-15r()-triol (5) and its isomer. thus in this investigation, two main goals were targeted, the first was to prove that compound 7 with its simple structure possess as potent activity as the other members reported in our previous work. the second goal was to develop a procedure to improve the synthesis of this compound to be produced as a sole reaction product and in a highest possible yield. we now report the in vitro chemopreventive activity, and an improved synthesis of the 7,8- epoxy-1,3,11-cembratriene-15r(),16-diol (7). the inhibition of ebv - ea activation was assayed using raji cells (virus non - producer type) using a previously described method. results of this assay (table 2) show that 7,8-epoxy-1,3,11-cembratriene-15r(),16-diol exhibits a strong inhibitory effect (about 95% inhibition at a concentration of 32 nmol / ml compared to 91.5% inhibition with sarcophytol - a at the same concentration). the results of the in vitro chemopreventive assay proved our hypothesis that the 1,2- propanediol moiety is responsible for enhancing the chemopreventive activity of the sarcophine molecule to an extent superior to sarcophytol - a. the second goal was accomplished through a detailed study of the different factors affecting the oxidation of the reduced sarcophine (time, temperature, grade and molar amount of selenium dioxide). it was found that when using 98.0 % selenium dioxide, the reaction proceeded much slower and in a more controllable way than when using 99.9 % grade. when the reaction of the reduced sarcophine with equimolar amounts of 98.0 % selenium dioxide was allowed to run at room temperature for just 15 minutes, it gave the 7,8-epoxy-1,3,11-cembratriene-15r(),16-diol (7) as an exclusive product with 90% yield. when the reaction was allowed to run for a longer time, additional formation of both 7,8-epoxy-1,3,11-cembratriene-13r(),15r(),16-triol (5) and its enantiomeric 7,8-epoxy-1,3,11-cembratriene-13r(),15r(),16-triol was observed. in conclusion, the improved synthesis of the 7,8-epoxy-1,3,11-cembratriene-15r(),16-diol (7), accomplished our goal in preparing a parent compound in a simple two steps reaction from sarcophine in an excellent yield, suitable for further derivatization for future sar studies of a new class of chemopreventive compounds. anhydrous 1,4-dioxane was purchased from aldrich chemical co. in sure seal bottles and used under nitrogen. selenium dioxide (98.0 %) was also purchased from aldrich chemical co. melting point (uncorrected) was determined in open capillary tube on a thomas hoover capillary melting point apparatus. the nmr spectra were obtained on bruker drx-400 operating at 400 mhz for h- and 100 mhz for c - nmr and chemical shifts were reported in ppm relative to internal chcl3 (7.26 ppm for h, 77 ppm for c). high - resolution fast atom bombardment mass (hrfabms) spectra were conducted at the university of kansas. high - resolution electron spray mass (hresms) spectra were obtained on bruker - magnex bioapex 30es spectrometer. analytical thin - layer chromatography (tlc) was performed on precoated silica gel g-25 uv254 plates (0.25 mm), visualized with short- and long wave uv light and/or iodine. the soft coral sarcophyton glaucum was collected on red sea in sharm - el - sheikh, egypt, at the depth of 16 ft (5 m). sarcophine was isolated from the extract by column chromatography on silica gel eluting with etoac - hexane (2:1), and crystallized from ethyl acetate. inhibition of epstien barr virus early antigen activation for primary screening on anti - tumor promoters was carried out at kyoto pharmaceutical university, japan. assays were performed as described previously. selenium dioxide (98.0 %, 1 mmol) was added a solution of the reduced sarcophine (8) (1 mmol) in dry 1,4-dioxane (30 ml), and the reaction mixture was stirred at room temperature for 15 minutes and followed by tlc for completion of reaction. the solvent was evaporated and the residue was chromatographed on silica gel using hexane : ethyl acetate (1:2) as an eluent to obtain the product (8590%). the product was identified by comparing its physical data and spectra with those an authentic sample as we previously reported. anhydrous 1,4-dioxane was purchased from aldrich chemical co. in sure seal bottles and used under nitrogen. selenium dioxide (98.0 %) was also purchased from aldrich chemical co. melting point (uncorrected) was determined in open capillary tube on a thomas hoover capillary melting point apparatus. the nmr spectra were obtained on bruker drx-400 operating at 400 mhz for h- and 100 mhz for c - nmr and chemical shifts were reported in ppm relative to internal chcl3 (7.26 ppm for h, 77 ppm for c). high - resolution fast atom bombardment mass (hrfabms) spectra were conducted at the university of kansas. high - resolution electron spray mass (hresms) spectra were obtained on bruker - magnex bioapex 30es spectrometer. analytical thin - layer chromatography (tlc) was performed on precoated silica gel g-25 uv254 plates (0.25 mm), visualized with short- and long wave uv light and/or iodine. the soft coral sarcophyton glaucum was collected on red sea in sharm - el - sheikh, egypt, at the depth of 16 ft (5 m). sarcophine was isolated from the extract by column chromatography on silica gel eluting with etoac - hexane (2:1), and crystallized from ethyl acetate. inhibition of epstien barr virus early antigen activation for primary screening on anti - tumor promoters was carried out at kyoto pharmaceutical university, japan. selenium dioxide (98.0 %, 1 mmol) was added a solution of the reduced sarcophine (8) (1 mmol) in dry 1,4-dioxane (30 ml), and the reaction mixture was stirred at room temperature for 15 minutes and followed by tlc for completion of reaction. the solvent was evaporated and the residue was chromatographed on silica gel using hexane : ethyl acetate (1:2) as an eluent to obtain the product (8590%). the product was identified by comparing its physical data and spectra with those an authentic sample as we previously reported. | an effective method for the synthesis of 7,8-epoxy-1,3,11-cembratriene- 15r(),16-diol and its in vitro epstein - barr virus early antigen (ebv - ea) activation chemopreventive assay are reported. this semisynthetic product is a new cembranoid with a potent tumor inhibitory activity that is expected to be a lead compound for a new class of chemopreventive agents of marine origin. |
mice, including nod / lt mice for tail - tip fibroblasts isolation, were maintained in a specific pathogen - free animal facility under monash university approved ethics (mmca2007/34). an 1.5 cm length of tail - tip from 8-week - old male nod mice was washed with 70% ethanol and pbs, the superficial dermis was peeled away, and the remaining tissue was cut into 1-mm pieces using a scalpel. five or six pieces were plated in one well of a six - well plate and cultured with 2 ml of nttf medium (dulbecco s modied eagle s medium with 10% fbs and 50 units / ml penicillin / streptomycin) for 57 days. retrovirus production and ipsc induction were performed as described previously with minor modifications (16). briefly, pmx - based retroviral vectors (addgene) encoding mouse oct4, sox2, and klf4 sequences were independently transfected into plat - e cells. the next day, nttfs at passage 4 were seeded at a density of 1 10 cells per well in six - well plates overnight. the virus - containing supernatants were collected 48 h after transfection, mixed, filtered, and added to the nttfs together with 4 g / ml polybrene (sigma - aldrich, st. louis, mo) for 24 h. subsequently, nttfs were cultured in mouse esc medium supplemented with 2 mol / l valproic acid (vpa), which was refreshed daily for 7 days. mouse esc culture medium was composed of knockout - dulbecco s modied eagle s medium, 20% knockout serum replacement, 0.1 mmol / l nonessential amino acids, 1 mmol / l glutamax, 0.1 mmol / l -mercaptoethanol (all from invitrogen, carlsbad, ca), and 1,000 units / ml leukemia inhibitory factor (lif) (millipore, billerica, ma). cells were cultured in a 37c, 5% co2 incubator. at day 14 after transduction the colonies were dissociated into single cells and transferred to wells in 96-well plates with mouse embryonic fibroblast (mef) feeder cells and 200 l esc medium. primary antibodies were oct4 (1:100, santa cruz biotechnology, inc., santa cruz, ca), nanog (1:100, abcam, cambridge, u.k.), and ssea-1 (1:100, millipore). total rna was isolated using the rneasy kit (qiagen, hilden, germany), and genomic dna contamination was removed using dna - free kit (ambion, austin, tx). one microgram of total rna was used for cdna synthesis using superscript iii reverse transcriptase and oligo (dt) primers (invitrogen). genomic dna was isolated from approximately 2 10 ipscs for each cell line using dneasy blood and tissue kit (qiagen). genomic dna from nod ips, es (d3 line), and nttf cells were extracted and processed for bisulfite genomic sequencing analysis as described previously (17). nested - pcr and sequencing was performed using primers listed in table 1. to form embryoid bodies (ebs) in vitro, nod - ipscs were dissociated into single cells and resuspended in mes medium without lif in bacteriological petri dishes (falcon, bd biosciences) for 1 week. to form teratomas in vivo, 2 10 nod ipscs were injected into the hind leg muscle of nod / scid mice. host embryos were collected at the blastocyst stage from c57bl/6 female mice at 3.5 days post coitum, and 1015 nod ipscs were injected into each. after a recovery period of 2 h, 10 to 15 injected blastocysts were transferred into one uterine horn of pseudopregnant cbac57bl/6 f1 female mice at 2.5 days post coitum. chimeric mice were identified by coat color, and the male chimera was assessed for germline transmission by mating with nod female mice. single cell suspensions were prepared from individual spleens and erythrocytes were lysed by treating the sample with tris - nh4cl followed by washing with facs buffer containing 2% fbs. fc receptor binding was blocked by incubating cells with 2.4g2 (bd biosciences pharmingen, san diego, ca). the following monoclonal antibodies were used in multiparameter flow cytometric analysis : anti - cd19 (6d5, alexa fluor 700 conjugated) and anti - h-2k (af688.5, percp / cy5.5 conjugated) from biolegend and anti - h-2k (sf11.1, fluorescein isothiocyanate conjugated), anti - i - a (ox-6, fluorescein isothiocyanate conjugated), and anti - i - a (af6120.1, phycoerythrin conjugated) from bd pharmingen. cells were analyzed with an lsr fortessa (bd biosciences, franklin lakes, nj) and flowjo (tree star) software using propidium iodide incorporation to exclude dead cells. dna was extracted from the nod - ips#5 cell line and genotyped for 112 microsatellite markers across the mouse genome covering 19 autosomes and the x chromosome., using the applied biosystems (carlsbad, ca) 3730 dna analyzer and ab gene mapper software. mice, including nod / lt mice for tail - tip fibroblasts isolation, were maintained in a specific pathogen - free animal facility under monash university approved ethics (mmca2007/34). an 1.5 cm length of tail - tip from 8-week - old male nod mice was washed with 70% ethanol and pbs, the superficial dermis was peeled away, and the remaining tissue was cut into 1-mm pieces using a scalpel. five or six pieces were plated in one well of a six - well plate and cultured with 2 ml of nttf medium (dulbecco s modied eagle s medium with 10% fbs and 50 units / ml penicillin / streptomycin) for 57 days. retrovirus production and ipsc induction were performed as described previously with minor modifications (16). briefly, pmx - based retroviral vectors (addgene) encoding mouse oct4, sox2, and klf4 sequences were independently transfected into plat - e cells. the next day, nttfs at passage 4 were seeded at a density of 1 10 cells per well in six - well plates overnight. the virus - containing supernatants were collected 48 h after transfection, mixed, filtered, and added to the nttfs together with 4 g / ml polybrene (sigma - aldrich, st. louis, mo) for 24 h. subsequently, nttfs were cultured in mouse esc medium supplemented with 2 mol / l valproic acid (vpa), which was refreshed daily for 7 days. mouse esc culture medium was composed of knockout - dulbecco s modied eagle s medium, 20% knockout serum replacement, 0.1 mmol / l nonessential amino acids, 1 mmol / l glutamax, 0.1 mmol / l -mercaptoethanol (all from invitrogen, carlsbad, ca), and 1,000 units / ml leukemia inhibitory factor (lif) (millipore, billerica, ma). cells were cultured in a 37c, 5% co2 incubator. at day 14 after transduction, colonies were picked individually and incubated with 20 l of 0.25% trypsin/1 mmol the colonies were dissociated into single cells and transferred to wells in 96-well plates with mouse embryonic fibroblast (mef) feeder cells and 200 l esc medium. primary antibodies were oct4 (1:100, santa cruz biotechnology, inc., santa cruz, ca), nanog (1:100, abcam, cambridge, u.k.), and ssea-1 (1:100, millipore). total rna was isolated using the rneasy kit (qiagen, hilden, germany), and genomic dna contamination was removed using dna - free kit (ambion, austin, tx). one microgram of total rna was used for cdna synthesis using superscript iii reverse transcriptase and oligo (dt) primers (invitrogen). genomic dna was isolated from approximately 2 10 ipscs for each cell line using dneasy blood and tissue kit (qiagen). genomic dna from nod ips, es (d3 line), and nttf cells were extracted and processed for bisulfite genomic sequencing analysis as described previously (17). nested - pcr and sequencing was performed using primers listed in table 1. to form embryoid bodies (ebs) in vitro, nod - ipscs were dissociated into single cells and resuspended in mes medium without lif in bacteriological petri dishes (falcon, bd biosciences) for 1 week. to form teratomas in vivo, 2 10 nod ipscs were injected into the hind leg muscle of nod / scid mice. host embryos were collected at the blastocyst stage from c57bl/6 female mice at 3.5 days post coitum, and 1015 nod ipscs were injected into each. after a recovery period of 2 h, 10 to 15 injected blastocysts were transferred into one uterine horn of pseudopregnant cbac57bl/6 f1 female mice at 2.5 days post coitum. chimeric mice were identified by coat color, and the male chimera was assessed for germline transmission by mating with nod female mice. single cell suspensions were prepared from individual spleens and erythrocytes were lysed by treating the sample with tris - nh4cl followed by washing with facs buffer containing 2% fbs. fc receptor binding was blocked by incubating cells with 2.4g2 (bd biosciences pharmingen, san diego, ca). the following monoclonal antibodies were used in multiparameter flow cytometric analysis : anti - cd19 (6d5, alexa fluor 700 conjugated) and anti - h-2k (af688.5, percp / cy5.5 conjugated) from biolegend and anti - h-2k (sf11.1, fluorescein isothiocyanate conjugated), anti - i - a (ox-6, fluorescein isothiocyanate conjugated), and anti - i - a (af6120.1, phycoerythrin conjugated) from bd pharmingen. cells were analyzed with an lsr fortessa (bd biosciences, franklin lakes, nj) and flowjo (tree star) software using propidium iodide incorporation to exclude dead cells. dna was extracted from the nod - ips#5 cell line and genotyped for 112 microsatellite markers across the mouse genome covering 19 autosomes and the x chromosome. genotyping was performed by the australian genome research facility ltd., using the applied biosystems (carlsbad, ca) 3730 dna analyzer and ab gene mapper software. 1a), clusters of cells started to aggregate together. by day 14 postviral infection, es - like colonies were individually picked, trypsinized, and transferred to mef feeder cells in 96-well plates for expansion (fig. a total of 41 putative colonies were picked in three replicated experiments, and 18 colonies were successfully expanded in six - well plates (supplementary table 1). the cells formed compacted colonies showing a refractile halo effect when observed by phase - contrast microscopy (fig. next, we transfected one of the nod - ipsc lines with an mcherry expression cassette (cmv - mcherry - hygro) by lipofectamine (invitrogen) as described previously (18). after selection with hygromycin and expansion, nttfs were plated at a density of 1 10 cells per well in six - well plates and infected with retroviruses encoding osk factors for 24 h. the infected nttfs were cultured in fibroblast medium for 2 days, switched to mouse esc medium supplemented with vpa for 1 week, and subsequently cultured in mouse esc medium. b : representative images of colonies observed at different stages as indicated in the panels (p, passage number) and the representative colonies stably transfected with cmv - mcherry - hygro construct. c : integration of oct4, sox2, and klf4 transgenes in the three osk - induced ipsc lines was confirmed by genomic pcr using transgene - specific primers, with h2o and nttf as negative controls and the construct plasmids as positive control. sox2, klf4, nanog, and rex1 ; expression of transgenes oct4, sox2, and klf4 in the tail - tip fibroblasts ; and the three osk - induced ipsc lines were assessed by rt - pcr, with h2o as negative control and appropriate samples as corresponding positive controls. e : immunofluorescence staining shows expression of pluripotency markers (oct4, nango, and ssea1) in the three osk - induced ipsc lines. genomic dna from mouse escs (esd3), fibroblasts (nttf), and the three osk - induced ipsc lines were processed for bisulfite sequencing. (a high - quality digital representation of this figure is available in the online issue.) of the 18 nod ipsc lines generated, three were selected for further characterization. we confirmed by genomic dna pcr that the three reprogramming transgenes (osk) were integrated in the genome of the ipscs (fig. rt - pcr analysis confirmed that osk transgenes were efficiently silenced in the three nod ipsc lines (fig. in addition, reactivation of endogenous oct4 and sox2 genes, as well as other pluripotent - associated transcription factors such as nanog and rex1 (also known as zfp42), was observed in all nod ipsc lines tested in the study (fig. immunohistochemical analysis showed that the ipscs stained positively for oct4, nanog, and ssea1 (fig. further, bisulfite sequencing analysis revealed that promoter regions examined for both oct4 and nanog were demethylated in nod - ipscs, in a manner similar to mouse escs (esd3 cell line), compared with heavily methylated patterns observed for the same regions in the parental nttf cells (fig. karyotyping analysis showed a normal chromosome number (40, xy) in the three ipsc lines (fig. 1 g), and genome - wide genotyping (112 microsatellite markers) of nod - ips # 5 cell line confirmed the nod genetic background (supplementary table 2). we next evaluated the differentiation potential of the nod ipscs in vitro by eb formation and in vivo by teratoma induction. the ipscs readily formed ebs on culture in the absence of feeders and lif (fig. rt - pcr of the ebs showed strong suppression of pluripotency genes including oct4 and nanog, with coincident activation of lineage - specific genes representing the three germ layers : nestin (ectoderm) ; vimentin and brachyury (mesoderm) ; and gata6, sox17, and foxa2 (endoderm) (fig. all three nod - ipsc lines generated well - differentiated teratomas in the nod / scid mice. hematoxylin - eosin staining of teratoma sections showed tissues representative of the germ layers, including keratinized - epithelium (ectoderm), cartilage (mesoderm), and secreting - gland epithelium (endoderm) (fig. 2c). a : in vitro differentiation of cmv - mcherry - hygro vector transfected nod ipscs to ebs (bright field and fluorescence field). b : rt - pcr analysis of total rna isolated from ebs generated from the three nod ipsc lines, one nod ipsc line (no. the expression of oct4 and nanog (pluripotency markers) ; vimentin and brachyury (mesoderm) ; gata6, foxa2, sox17 (endoderm markers) ; and nestin (ectoderm marker) were examined. histologic analysis of teratomas indicates ipscs contribute to tissues from the three germ layers, including keratinized - epithelium (ectoderm), cartilage (mesoderm), and secreting - gland epithelium (endoderm). d : contribution of nod - ips#5 cells in chimeric mouse (xa2401) as detected by agouti coat color. e : hematopoietic chimerism assessment by flow cytometry analysis of spleen samples from a wild - type nod mouse, the chimeric mouse (xa2401), and a c57bl/6 mouse. top : h-2k (c57bl/6) and h-2k (nod) mhc class i expression on cd19 cells. bottom : i - a (c57bl/6) and i - a (nod) mhc class ii expression on cd19 cells. (a high - quality digital representation of this figure is available in the online issue.) a total of 24 c57bl/6 blastocysts injected with nod - ips#5 cells were transferred into the uteri of two pseudopregnant mice. both recipients became pregnant and delivered a total of 17 pups, with one male pup (designated as xa2401) showing 4050% coat color chimerism (fig. we crossed the chimeric male with wild - type nod female mice to examine germ - line transmission capability ; however, no albino offspring resulted from three litters examined (18 pups born). last, we assessed the hematopoietic chimerism of male xa2401 by cell surface marker expressions of the major histocompatibility complex (mhc). nod mice express the mhc class i molecule k and class ii molecule i - a, whereas c57bl/6 mice express k and i - a molecules, respectively. flow cytometric analysis of b - cell expression of mhc molecules in the spleen indicated that the xa2401 mouse showed a c57bl/6 hematopoietic system (fig. the major goal of our current research was to demonstrate that somatic fibroblasts from nod mice can be reprogrammed to generate ipscs. we used three yamanaka factors, oct4, sox2, and klf4, but not c - myc, to fulfill the reprogramming process of nttf in this study. c - myc was excluded because previous studies have shown that potential reactivation of the c - myc transgene could result in tumor development in the chimeras and their progeny derived from the ipscs (9,19). instead, the chromatin remodeling small - molecule vpa (a histone deacetylase inhibitor) was used because it has been shown to greatly increase the efficiency of reprogramming human and mouse fibroblasts (20,21). male (xy) donor cells were also chosen for induction to pluripotency for three reasons. 1) male pluripotent cell - derived differentiated cells are easier to track in vivo, based on y - chromosome specific probes, when used for transplantation studies into female recipients. 2) aberrant x - inactivation associated with female (xx) esc lines can result in xo cells, which compromises euploidy of cells, chimera generation, and germ - line transmission (22,23). 3) male esc chimeras can be rapidly bred with more than one wild - type female to produce multiple litters. by using this modified approach, we show that nod ipscs are readily generated from nttfs by transduction with retroviral vectors encoding oct4, sox2, and klf4 and supplementation with vpa in the culture medium for 1 week. all three transgenes were silenced in the nod ipscs, suggesting complete reprogramming of the somatic nttf. the nod ipscs could be dissociated into single cells by trypsinization and maintained for > 50 passages. the nod ipscs derived in this study maintained esc - like pluripotent characteristics and did not convert to an epiblast stem (epis) cell - like state, which is characterized by distinct colonies with flat morphology (24,25). (4), because their nod ipscs appeared to be metastable and acquired an alternative epis cell - like identity after removal of exogenous klf4 or cmyc factor expression. the epis cell colonies not only were morphologically distinct from mouse escs but also lost the ability to be propagated after dissociation into single cells by trypsinization. in our study, the derivation and maintenance of nod ipscs were achieved without constitutive expression of klf4 transgene or addition of small molecules of gsk3/erk pathway inhibitors. this difference may be due to the source of adult somatic tissue : we used nttf, whereas hanna. nonetheless, our modified method provides a robust alternative strategy for the generation of esc - like pluripotent stem cells from a nonpermissive mouse strain without using embryos. | objectivethe nod mouse strain has been widely used to investigate the pathology and genetic susceptibility for type 1 diabetes. induced pluripotent stem cells (ipscs) derived from this unique mouse strain would enable new strategies for investigating type 1 diabetes pathogenesis and potential therapeutic targets. the objective of this study was to determine whether somatic fibroblasts from nod mice could be reprogrammed to become ipscs, providing an alternative source of stem cells for the production of genetically modified nod cells and mice.research design and methodsadult tail - tip fibroblasts from male nod mice were reprogrammed by retroviral transduction of the coding sequences of three transcription factors, oct4, sox2, and klf4, in combination with a histone deacetylase inhibitor, valproic acid.resultseighteen nod ipsc lines were generated, and three of these cell lines were further characterized. all three cell lines exhibited silencing of the three reprogramming transgenes and reactivation of endogenous pluripotent markers (oct4, sox2, nanog, rex1, and ssea1). these nod ipscs readily differentiated in vitro to form embryoid bodies and in vivo by teratoma formation in immunodeficient mice. moreover, nod ipscs were successfully transfected with a reporter transgene and were capable of contributing to the inner cell mass of c57bl/6 blastocysts, leading to the generation of a chimeric mouse.conclusionsadult tail - tip fibroblasts from nod mice can be reprogrammed, without constitutive ectopic expression of transcription factors, to produce ipscs that exhibit classic mouse embryonic stem cell (esc) features. these nod ipscs can be maintained and propagated under normal esc culture conditions to produce genetically altered cell lines, differentiated cells, and chimeric mice. |
multivalent ions are known to allow for reversible cross - linking in soft biological materials, providing stiffness and extensibility via sacrificial bonds. we present a simple model where stiff nanoscale elements carrying negative charges are coupled in shear by divalent mobile cations in aqueous media. such a shear coupling through a soft glue has, indeed, been proposed to operate in biological nanocomposites. while the coupling is elastic and brittle when the negative charges are periodically arranged, sufficient randomness in their distribution allows for large irreversible deformation. |
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in 1994, the metropolitan area environmental health service (health service) began a gastroenteritis outbreak surveillance program in the centers. this study was to determine the role of hucvs as a cause of gastroenteritis outbreaks from june 1, 2000, to january 30, 2003, in santiago, chile, by using recently improved antigen and genome detection assays, and to characterize genetically the circulating strains. sentinel sites were instructed to report gastroenteritis outbreaks 48 hours after detecting the sentinel case. a health service epidemiologist would initiate an investigation and make home visits to identify all persons possibly involved in the outbreak. stools samples for pathogen detection were collected during home visits from affected persons and were cultured for salmonella, shigella, campylobacter, and vibrio spp., according to standard techniques using selective media (10). enteropathogenic escherichia coli, enterotoxigenic e. coli, and enterohemorrhagic e. coli were studied by multiplex polymerase chain reaction (11) and enzyme - linked immunosorbent assay (elisa). rotavirus and enteric adenoviruses were detected by elisa or by commercial kits (sas rota test, sa scientific inc., san antonio, tx, usa ; premier adenoclone, meridian diagnostics inc., cincinnati, oh, usa ; 40/41 adeno - strip, coris bioconcept, gembloux, belgium) and parasites were detected by burrows technique. all samples were tested for hucv by a novel elisa specific for noroviruses based on pools of sera obtained from rabbits and guinea pigs hyperimmunized with a total of 9 different norovirus capsids (12) and by reverse transcription polymerase chain reaction (rt - pcr) targeting conserved sequences in the polymerase region of hucvs (9). primers used for rt - pcr were 289 (rt)/290 (pcr) or a pool of degenerate primers of last generation, 289hi for rt and 290hijk for pcr, that detect norovirus and sapovirus (13,14). rt - pcr products were cloned by using pgem - t easy vector system (promega, madison, wi, usa). the 327-base nucleotide sequences that encode for the polymerase dependent rna were aligned by using omiga 2.0 (oxford molecular, madison, wi, usa) software and compared with 21 prototype sequences retrieved using blast searches from the genbank database. phylogenetic distances were calculated by kimura 2-parameter method and a phylogenetic tree was plotted by the neighbor - joining method using mega, version 2.1 (15). during the 30-month study, a total of 82 outbreaks affecting 100 persons in the santiago metropolitan area were reported properly to the health service and investigated. in each outbreak, a rectal swab from 1 person was collected for microbial studies. in each of 55 outbreaks, 1 stool sample was collected for virus studies, and in each of 31 outbreaks, 1 stool sample was collected for parasite studies. enteric microbial pathogens were isolated in samples from 1 person in 32% of the 82 outbreaks, and potentially pathogenic parasites were isolated in 6 (19%) of 31 outbreaks (table 1). a total of 175 samples from 55 outbreaks were obtained for viral detection, of which 47 (27%) from 25 (45%) outbreaks were positive for hucv by using 1 method. hucv outbreaks affected 99 persons with a median of 5 persons (table 1). in 16 outbreaks, 2 persons were positive by using elisa or rt - pcr ; in 9 outbreaks, 1 person was positive by 1 method. overall, 20% of the outbreaks were detected only by elisa, 24% only by rt - pcr, and 56% by both techniques. an outbreak was associated with a given pathogen if 1 sample was positive. bacteria isolated included : enteropathogenic escherichia coli (epec) (2), enterotoxigenic e. coli (etec) (3), enterohemorrhagic e. coli (3), epec + etec (1), salmonella sp (12), shigella sp (2), staphylococcus aureus (3). january 110, 2003. in 1 outbreak, etec and epec and in another, shiga toxin in 1 additional outbreak the only pathogens simultaneously detected in 1 patient were rotavirus and adenovirus by enzyme - linked immunosorbent assay. most hucv outbreaks occurred in the home, with outbreaks in childcare centers and schools occurring next most frequently ; only a small fraction occurred in restaurants. the most commonly implicated food products were seafood, including raw oysters and clams (table 2). among a total of 1,137 persons exposed in the 25 hucv outbreaks, 283 (25%) had typical acute gastroenteritis symptoms. thirty - nine percent of the cases occurred in children 60 years of age. most commonly reported symptoms were diarrhea (86%), vomiting (36%), and fever (16%). hucv amplicons from 13 outbreaks evaluated belonged to the norovirus genus, including 8 gii, 2 gi, and 3 in a potentially novel genogroup. the 3 new strains differed > 40% in nucleotide identity from all prototype strains compared (figure). bootstrap analysis based upon 1,000 generated trees yielded a node for the potentially novel genogroup in 100% of the trees. two of the outbreaks caused by this potentially novel genogroup occurred during the same month, while the third occurred a year later. one of the genetic clusters, represented by strain 028/10 - 2001, was closely related with a distance of 0.11 to saitama virus (saiu1, accession no. ab039775), a japanese strain found in 1998 in a child with acute gastroenteritis. the 2 other genetic clusters are proposed as novel genetic clusters and include strains (i) o55/5 - 2002, o64/10 - 2002, o62/9 - 2002, o71/11 - 2002, o78/11 - 2002, and (ii) o77/11 - 2002, o85/1 - 2003 (figure). the first cluster has 2 independent nodes with a distance of 0.19 to 0.28 from saiu1, the second cluster is represented by 2 strains with a distance of 0.18 and 0.19 from saiu1, respectively. phylogenetic tree of noroviruses based on the 327-base region of the 3 end of the open reading frame 1 using 13 novel sequences designated according to outbreak number / month year (example : o55/52002), and 21 sequences of norwalk - like virus strains representative of the currently identified genogroups, designated according to genbank accession number. comparative strains include : norwalk virus (m87661), saitamau1 (ab039775), saitama u201 (ab039782), wug1 (ab081723), schreier (af093797), camberwell (af145896), fort lauderdale (af414426), saint cloud (af414427), jena (aj011099), maryland (ay032605), murine nv (ay228235), southampton (l07418), oth25 (l23830), snow mountain (l23831), toronto (u02030), desert shield virus (u04469), hawaii (u07611), mexico (u22498), bristol (x76716), melksham (x81879), and lorsdale (x86557). bootstrap values based on 1,000 generated trees are displayed at the nodes (values > 60% are shown). hucvs were associated with almost half of 55 fully evaluated gastroenteritis outbreaks in santiago, chile, and were more common than outbreak - associated enteric bacterial pathogens such as salmonella sp. and diarrheogenic e. coli. to our knowledge, this is the first prospective, active surveillance for gastroenteritis outbreaks in latin america that included a thorough search for hucvs. publications from the region have described high seroprevalence for these viruses (3,16) and have reported isolated outbreaks affecting children and adults (3,8). hucv - associated outbreaks mostly affected children that ate seafood in homes ; other implicated sources included meat products and vegetables. the reported outbreaks in this study reflect the tip of the iceberg ; only 10% of all reported outbreaks could be studied because of capacity and resources for prompt reporting and investigation. this study should stimulate efforts for appropriate outbreak investigation in developing regions where food products safety is important for the health of the population, tourism, and international commerce. genogroup ii strains dominated, as in other studies (36), but only 1 of these strains fell into the same genetic cluster of a previously described strain, saitama virus ; in contrast, most strains grouped into 2 closely related new clusters. in addition, 3 strains, 2 temporally related, likely belong to a new genogroup. the circulation of genetically diverse strains indicates the need for further studies to understand the clinical and epidemiologic importance of such diversity. | human caliciviruses caused 45% of 55 gastroenteritis outbreaks occurring in santiago, chile, during 20002003. outbreaks affected 99 persons, occurred most commonly in the home, and were associated with seafood consumption. thirteen outbreak strains sequenced were noroviruses, including 8 gii, 2 gi, and 3 belonging to a novel genogroup. |
the primary risk factor for both alzheimer s disease (ad) and vascular dementia (vad) is age. the extension of life expectancy results in a rising number of patients with dementia and associated symptoms. the core syndrome of dementia, which serves as a key diagnostic feature, is cognitive impairment, but neuropsychiatric symptoms (npss) are common as well. almost all people with dementia are affected by these symptoms at some point during the progression of the disorder.1 this may result in long - term hospitalization, increased use of medication, and a decrease in quality of life for patients and caregivers.2 prevalence of any one nps was 61% in a cross - sectional study, and 69%, who were symptom - free at baseline, had at least one symptom when followed up 18 months later.3,4 in another study, 75% of dementia patients exhibited at least one such symptom in the previous month ; two or more symptoms were observed in 55% of cases.5 between 43% and 47% of patients with mild cognitive impairment (mci) exhibited at least one neuropsychiatric symptom, and up to 80% of the demented patients had presented at least one neuropsychiatric symptom since the beginning of their cognitive impairment.5,6 neuropsychiatric symptoms are associated with dementia from its early beginning and can not be described as concomitant features of advanced disease states.5 like cognitive disturbances, they should be considered as an integral part of the core psychopathology.5,7 there were no differences in the prevalence of npss in patients with ad type or other forms of dementia, including vad, apart from the item aberrant motor behavior, which was more frequent in ad. the most frequent symptoms in dementia patients were apathy, depression, and agitation / aggression.5 nps severity was no different between ad and vad patients on initial assessment of a memory disorders clinic population with mild to moderate dementia. however, npss increased with severity of dementia in this group.8 ginkgo biloba extract egb 761 has been reported to be effective in the symptomatic treatment of dementia, in particular when npss are present.912 clinically significant effects of egb 761 on npss have been described for patients suffering from age - associated cognitive decline as well as for patients with dementia.1315 the molecular basis of such effects is not yet fully understood, but there is evidence of neuroprotective properties, including inhibition of synaptotoxic a oligomer formation as well as antagonism of -amyloid toxicity.1619 egb 761 is a polyvalent radical scavenger that improves mitochondrial function,2022 decreases blood viscosity, and enhances microperfusion.23 modulation of the serotonin system,24 increasing dopamine levels in prefrontal cortical areas,25 perhaps by inhibition of the norepinephrine transporter,26 attenuation of a hyperactivated hypothalamus pituitary adrenal (hpa) axis,2729 and improvement of neuronal insulin sensitivity may play a role, since these pharmacodynamic actions of egb 761 target pathomechanisms that are common to dementia and behavioral disorders. here we report on secondary analyses of data from a recently published clinical trial of a once - daily formulation containing 240 mg of ginkgo biloba extract egb 761.12 the goal of these secondary analyses was the assessment of treatment effects of egb 761 on single npss in patients with dementia as well as on relieving the related caregiver distress. the clinical trial was conducted in accordance with the declaration of helsinki, the international conference on harmonization (ich) guideline for good clinical practice (gcp), and the provisions of local laws.30 the protocol was approved by the ethics committee of the state pharmacology center at the ukraine ministry of health. before enrolment, oral and written informed consent was obtained from all patients and their caregivers. at a start - up meeting, investigators and clinical staff involved in the trial were trained in gcp standards and legal requirements. moreover, they were trained by experienced psychiatrists and neuropsychologists in the administration of tests and rating scales used for diagnosis and efficacy assessment. patient selection, patient disposition, trial design, and methods are described in detail elsewhere.12 briefly, outpatients (50 years of age, 20 centers) with mild to moderate dementia due to probable ad (according to nincds / adrda research diagnostic criteria),31 possible ad (nincds / adrda) with cerebrovascular disease (cvd) (as specified by ninds / airen criteria) or probable vad (ninds / airen) were admitted32 if they scored 35 or worse in the cognitive part of the test for early detection of dementia with discrimination from depression (te4d - cog),33 between 9 and 23 in the skt cognitive test battery total score,34,35 below 6 in the clock - drawing test (cdt),36 and at least 5 on the 12-item neuropsychiatric inventory (npi).7 in at least one item of the npi (except delusions or hallucinations), patients had to score at least 3, and their total score on the hamilton rating scale for depression (hamd) had to be less than 20.37 a caregiver had to be available to provide information on the patient s behavior and ability to perform activities of daily living. patients suffering from other psychiatric or neurological disorders or having severe somatic illnesses were excluded. treatment with other antidementia drugs, ginkgo supplements, cholinergic, anti - cholinergic or hemorheologically active drugs was prohibited throughout the trial. after a medication - free screening period of up to 4 weeks, patients were randomly assigned to receive either ginkgo biloba extract egb 761 at a dose of 240 mg once a day or placebo in a double - blind fashion during the subsequent 24-week treatment period. egb 761 is a dry extract from ginkgo biloba leaves (3567:1), extraction solvent : acetone 60% (w / w). the extract is adjusted to 22.0%27.0% ginkgo flavonoids, calculated as ginkgo flavone glycosides, and 5.0%7.0% terpene lactones, consisting of 2.8%3.4% ginkgolides a, b, c, and 2.6%3.2% bilobalide, and contains less than 5 ppm ginkgolic acids. drug and placebo were manufactured and provided by dr willmar schwabe gmbh and co. kg, karlsruhe, germany. considering the emphasis on neuropsychiatric features at inclusion, the 12-item npi was chosen to be a primary efficacy measure in addition to the skt (a cross - culturally validated 9-item cognitive test battery). each of the 12 types of abnormal behavior is explored by a number of pertinent screening questions and, if present, scored by its frequency of occurrence and its severity. the total composite score obtained by summing up the single item scores may range from 0 to 144, with higher scores indicating more behavioral problems. in addition, a score for caregivers distress is assigned for each type of abnormal behavior present. the total distress score may range from 0 to 60, with higher scores indicating more severe distress suffered by the caregiver. an improvement in the total composite score by four points or more in an individual patient is judged by experts to be clinically significant.38 the npi caregivers distress score and the rate of clinically meaningful response (improvement by at least 4 points on the npi composite score) were therefore also included as secondary outcome measures. safety was assessed by physical examination, electrocardiography, and laboratory tests at screening and week 24. adverse events were recorded at all regular visits, at week 6, and week 18 by phone calls and at the study termination visit (week 24 or early termination). the methods for the statistical analysis are described in detail elsewhere.12 in short, two primary endpoints, the change in the skt total score and the npi total score, were defined to assess efficacy in the cognitive and neuropsychiatric domain, respectively. these endpoints were analyzed using an overall type - i error rate of = 0.05 by applying an analysis of covariance procedure with the factors treatment and center and the baseline value of the respective variable as a covariate. the analysis was based on the full analysis dataset according to the intention - to - treat principle and included all patients who received randomized study treatment at least once and had at least one measurement of the primary efficacy parameters during the randomized treatment period. secondary efficacy variables as presented in this paper were evaluated descriptively without control of the type - i error rate, and the p - values should be considered accordingly. patient selection, patient disposition, trial design, and methods are described in detail elsewhere.12 briefly, outpatients (50 years of age, 20 centers) with mild to moderate dementia due to probable ad (according to nincds / adrda research diagnostic criteria),31 possible ad (nincds / adrda) with cerebrovascular disease (cvd) (as specified by ninds / airen criteria) or probable vad (ninds / airen) were admitted32 if they scored 35 or worse in the cognitive part of the test for early detection of dementia with discrimination from depression (te4d - cog),33 between 9 and 23 in the skt cognitive test battery total score,34,35 below 6 in the clock - drawing test (cdt),36 and at least 5 on the 12-item neuropsychiatric inventory (npi).7 in at least one item of the npi (except delusions or hallucinations), patients had to score at least 3, and their total score on the hamilton rating scale for depression (hamd) had to be less than 20.37 a caregiver had to be available to provide information on the patient s behavior and ability to perform activities of daily living. patients suffering from other psychiatric or neurological disorders or having severe somatic illnesses were excluded. treatment with other antidementia drugs, ginkgo supplements, cholinergic, anti - cholinergic or hemorheologically active drugs was prohibited throughout the trial. after a medication - free screening period of up to 4 weeks, patients were randomly assigned to receive either ginkgo biloba extract egb 761 at a dose of 240 mg once a day or placebo in a double - blind fashion during the subsequent 24-week treatment period. egb 761 is a dry extract from ginkgo biloba leaves (3567:1), extraction solvent : acetone 60% (w / w). the extract is adjusted to 22.0%27.0% ginkgo flavonoids, calculated as ginkgo flavone glycosides, and 5.0%7.0% terpene lactones, consisting of 2.8%3.4% ginkgolides a, b, c, and 2.6%3.2% bilobalide, and contains less than 5 ppm ginkgolic acids. drug and placebo were manufactured and provided by dr willmar schwabe gmbh and co. kg, karlsruhe, germany. considering the emphasis on neuropsychiatric features at inclusion, the 12-item npi was chosen to be a primary efficacy measure in addition to the skt (a cross - culturally validated 9-item cognitive test battery). each of the 12 types of abnormal behavior is explored by a number of pertinent screening questions and, if present, scored by its frequency of occurrence and its severity. the total composite score obtained by summing up the single item scores may range from 0 to 144, with higher scores indicating more behavioral problems. in addition, a score for caregivers distress is assigned for each type of abnormal behavior present. the total distress score may range from 0 to 60, with higher scores indicating more severe distress suffered by the caregiver. an improvement in the total composite score by four points or more in an individual patient is judged by experts to be clinically significant.38 the npi caregivers distress score and the rate of clinically meaningful response (improvement by at least 4 points on the npi composite score) were therefore also included as secondary outcome measures. safety was assessed by physical examination, electrocardiography, and laboratory tests at screening and week 24. adverse events were recorded at all regular visits, at week 6, and week 18 by phone calls and at the study termination visit (week 24 or early termination). the methods for the statistical analysis are described in detail elsewhere.12 in short, two primary endpoints, the change in the skt total score and the npi total score, were defined to assess efficacy in the cognitive and neuropsychiatric domain, respectively. these endpoints were analyzed using an overall type - i error rate of = 0.05 by applying an analysis of covariance procedure with the factors treatment and center and the baseline value of the respective variable as a covariate. the analysis was based on the full analysis dataset according to the intention - to - treat principle and included all patients who received randomized study treatment at least once and had at least one measurement of the primary efficacy parameters during the randomized treatment period. secondary efficacy variables as presented in this paper were evaluated descriptively without control of the type - i error rate, and the p - values should be considered accordingly. the main results for the primary and secondary outcome parameters of this randomized, placebo - controlled clinical trial have been reported elsewhere.12 here we describe the treatment effects of egb 761 and placebo on neuropsychiatric symptoms of dementia derived from single npi items, total composite scores, and caregiver distress scores. baseline characteristics of patients, broken down by treatment group, are presented in table 1. the mean npi total score dropped by 3.2 6.1 (mean standard deviation) points in the egb 761-treated patients between baseline and week 24. the mean caregiver distress score decreased in parallel by 1.2 3.4 points. in patients receiving placebo, the npi total score remained unchanged (0.0 6.1), and the corresponding caregiver distress score increased slightly by 0.3 3.4. drug placebo differences were statistically significant (p < 0.001, two - sided t - test) in both between - group comparisons. a clinically meaningful response, defined as an improvement by at least 4 points on the npi total score,38 was achieved in 45.0% of patients treated with egb 761 and in 23.8% of patients receiving placebo (p < 0.001, two - sided -test, for between - group comparison). the mean composite and distress scores at baseline for all 12 npi items are shown in table 2. the highest baseline composite scores were found for apathy / indifference, sleep / night - time behavior, irritability / lability, and anxiety. caregivers reported that irritability / lability, sleep / night - time behavior, and apathy / indifference were the most distressing symptoms. as shown in figure 1, the average improvements in npi composite scores after the 24-week egb 761 treatment period were most pronounced for sleep / night - time behavior, apathy / indifference, irritability / lability, aberrant motor behavior, and depression / dysphoria (all statistically significantly different from placebo as indicated in figure 1). a similar effect profile is observed for changes in caregiver distress scores, with marked effects also observed in sleep / night - time behavior and depression / dysphoria (statistically significantly different from placebo as indicated in figure 2). egb 761 was safe and well tolerated, with a lower number of adverse events reported in the active treatment group than in the placebo group. specifically, dizziness and tinnitus occurred more frequently under placebo treatment. significant treatment effects of a once - daily application of 240 mg egb 761 on many of the neuropsychiatric symptoms evaluated by the 12-item npi were found in prospective secondary analyses of this clinical trial. these results further support the efficacy of the once - daily application of ginkgo biloba extract egb 761 in the treatment of patients with ad, vad, or dementia with mixed pathology associated with npss, as demonstrated by confirmatory primary analysis based on the npi total score. clinical efficacy of egb 761 in the treatment of npss has already been postulated by hoerr, who reviewed former studies in patients with age - associated cognitive decline, and it was confirmed recently by scripnikov for patients with dementia.13,15 our clinical trial focused on patients with dementia ad, vad, or mixed type who were selected specifically as suffering from npss. this was achieved by stipulating a baseline composite score of at least 5 points on the 12-item npi, with at least one item score not lower than 3. the npi total composite score also served as a co - primary outcome criterion for the efficacy assessment. the profile of npss in our population is slightly different from those reported in a previous 22-week trial of egb 761, and the baseline severity of symptoms is lower.15,39 disease severity and stage - specific differences in behavioral symptom manifestations might influence overall treatment response as measured by an aggregate assessment tool such as npi.40 as a consequence, the reported response rate (improvement by at least 4 points) might be lower in our clinical trial, in which the deterioration of symptoms in the placebo group was less pronounced, and even some slight improvement was observed in some symptoms with placebo treatment. the pattern of neuropsychiatric symptoms found in our patients was consistent with that reported from a population - based study in which patients with dementia also scored highest for the symptoms apathy / indifference, anxiety, depression / dysphoria, agitation / aggression, aberrant motor behavior, and irritability / lability.3 it therefore appears that our sample was quite representative of dementia patients encountered in everyday practice. the caregiver distress scores at baseline closely match those of the npi composite scores, with slight differences in ranking of severity of apathy / indifference, sleep / night - time behavior, and irritability / lability. overall, the symptoms rated as most prominent in the patients were also perceived as most disturbing by the caregivers. similarly, the relief from distress, which was experienced by caregivers during the treatment period, seems to be driven by the symptoms that improved most in the patients. the elevation and stabilization of mood and the observed decrease in anxiety levels seem to be in line with the effects of egb 761 on the dopamine and serotonin systems as well as on the hpa axis.2429 recently, a pooled data analysis of the moderate - affinity n - methyl - d - aspartate receptor antagonist memantine, a descriptive review of cholinesterase inhibitors and memantine, and a review of randomized, placebo - controlled trials of donepezil, rivastigmine, and galantamine summarized the evidence for the efficacy of these substances in the treatment of npss.4042 beneficial effects of memantine were reported for delusions and agitation / aggression in patients with moderate to severe ad.41 cummings concluded that most double - blind, placebo - controlled trials and open - label assessments suggest some treatment benefit of antidementia agents, though not all demonstrated drug placebo differences.40 this is consistent with the summary conclusion that, at best, cholinesterase inhibitors appear to have a modest impact on the broad spectrum of npss in ad. in contrast, egb 761 showed a significant effect on a broad range of symptoms. however, caution is warranted when trying to compare treatment effects observed in different studies, because they may depend on the characteristics of the particular patient population, such as profile and severity of behavioral symptoms at baseline, severity or stage of dementia, residential status, linguistic and cultural diversities of study sites, and use of psychotropic drugs. moreover, the 10-item version of the npi was used in some of the earlier trials. in summary, the present, and a previous independent trial in patients selected using the same criteria for dementia and npss,15 consistently demonstrated statistically significant and clinically relevant drug placebo differences in favor of egb 761 for the composite score, the caregiver distress score, and several npi item scores (eg, apathy / indifference, sleep / night - time behavior, irritability / lability, depression / dysphoria). the importance of alleviating npss is underlined by the negative impact such symptoms have on the quality of life of patients with dementia,4345 the burden experienced by caregivers, and the roles that npss and nps - related caregiver distress play in decisions about nursing home placement.4648 it can be concluded that ginkgo biloba extract egb 761 at a once - daily dose of 240 mg is safe and effectively alleviates npss in patients with ad, vad, and dementia with mixed pathology, benefitting both patients and their caregivers. | purpose : to examine the effects of ginkgo biloba extract egb 761 on neuropsychiatric symptoms of dementia.patients and methods : randomized, controlled, double - blind, multicenter clinical trial involving 410 outpatients with mild to moderate dementia (alzheimer s disease with or without cerebrovascular disease, vascular dementia), scoring at least 5 on the neuropsychiatric inventory (npi), with at least one item score of 3 or more. total scores on the skt cognitive test battery (erzigkeit s short syndrome test) were between 9 and 23. after random allocation, the patients took 240 mg of egb 761 or placebo once daily for a period of 24 weeks. changes from baseline to week 24 in the npi composite and in the skt total score were the primary outcomes. the npi distress score was chosen as a secondary outcome measure to evaluate caregivers distress.results:the npi composite score improved by 3.2 (95% confidence interval 4.0 to 2.3) in patients taking egb 761 (n = 202), but did not change (0.9 ; 0.9) in those receiving placebo (n = 202), which resulted in a statistically significant difference in favor of egb 761 (p < 0.001). treatment with egb 761 was significantly superior to placebo for the symptoms apathy / indifference, sleep / night - time behavior, irritability / lability, depression / dysphoria, and aberrant motor behavior. caregivers distress evaluation revealed similar baseline pattern and improvements.conclusion:treatment with egb 761, at a once - daily dose of 240 mg, was safe, effectively alleviated behavioral and neuropsychiatric symptoms in patients with mild to moderate dementia, and improved the wellbeing of their caregivers. |
polymethyl methacrylate (pmma) as denture base material has many advantages including adequate mechanical strength, esthetics, low toxicity, easiness of repair, and can be cured by simple procedures, therefore, pmma has been the most commonly used for fabricating denture base since it was developed in the mid-1945.12 however, pmma resin also has some disadvantages as denture base, and one of these is dimensional change after processing was completed. dimensional change of denture base resin can be occurred by curing shrinkage and expansion through water absorption,3 and other former studies stated that dimensional change would be a result of polymerization shrinkage,45 thermal shrinkage,46 internal stress release,6 water absorption,78 and dry shrinkage.9 the denture base after curing may have shrunk linearly as much as approximately 0.5%.10 it could lead distortion of the denture, and although this shrinkage may be compensated with expansion by water absorption, this change would result in poor adaptation of the denture to its tissue, and decrease of denture stability and retention.611 concerning water absorption, some studies demonstrated that the greatest dimensional changes was occurred during the first month and no remarkable changes took place after two months.12 due to pmma denture base should be influenced by water absorption, some authors insisted that occlusal adjustment of denture would be delayed until pmma has become saturated with water.7 however, some authors researched about changes in dentures during storage in water and in service for 18 months, and concluded a posterior linear expansion of heat curing resin was less than 1.0% and the dimensional changes did not affected the fit of denture,8 and other studies also reported that there was no significant volumetric deformation in denture when denture was being stored in water.13 most of previous studies tried to measure deformation and accuracy of the denture 2-dimensionally.141516 nowadays, some authors tried to investigate the dimensional stability, and it is possible to compare two objects three - dimensionally by using surface matching program and scanning device.17 it is well known that denture should be stored in the water in order to minimize distortion and shrinkage, when they are once removed from the mouth.714 however, it was not known shrinkage was occurred in certain pattern of form when denture was kept in dry condition, nor which portion of the denture should be watched carefully, if the patient who stores his denture in the air comes and want to relieve discomfort due to his denture. the purpose of this study was to evaluate whether there is any typical deformation pattern of complete denture that was stored in the air, and if any, to find out what typical pattern would be by using the 3d scanner and surface matching program. for fabricating upper and lower denture base, maxillary and mandibular edentulous models with little undercut were selected. additional silicone material (honigum, dmg, hamburg, germany) the silicone molds were poured with improved stone (fujirock ep pastel yellow ; gc america inc., alsip, il, usa) thus total 28 master casts, including 14 maxillary and 14 mandibular models, were fabricated. after trimming the master cast, recording base with 2.0 mm thickness was made with auto - polymerizing resin (quicky, nissin dental product, inc.,, each recording base was sit onto the corresponding cast and gap between recording base and master cast was sealed with molten baseplate wax. after waxes were washed out with boiling water, heat polymerized acrylic resin (lucitone 199, dentsply international inc, york, ny, usa) was packed into the mold and polymerized for 9 hours at 72 and maintained for 30 minutes at 100. flasks were cooled down to room temperature in the water for 12 hours. after denture base was removed from the cast, any nodule or fin edge on the denture base are carefully removed with acrylic bur. total 28 denture bases were fabricated, and 14 denture bases (7 upper and 7 lower denture bases) were stored in the water bottle (water stored), and another 14 denture bases were stored in the air (dry stored). 3d laser scanner (myscan specification, raphabio, seoul, korea), which could detect 0.02 mm difference was used for digitizing the denture base. to confirm that denture specimen was mounted on the similar position of the scan table, silicone putty index was fabricated for each denture base specimen and each denture base was mounted with it. scanned data was saved as stereolithography (stl) file using data compatible program (mydesign, raphabio, seoul, korea). internal surface of each specimen was scanned at 1 day, 14 day and 28 day after deflasking. 3d scan data of internal surface of denture base were categorized depending on the storage method (w ; water storage, d ; dried storage), and subdivided into t1, t2, and t3 according to duration from deflasking to scanned time ; 1 day after deflasking, 14 day after deflasking, and 28 day after deflasking, respectively. three dimensional deformation patterns were acquired by overlapping the scanned data between t1 and t2, t2 and t3, and t1 and t3 of each storage group by 3d surface matching program (geomagic qualify ; raindrop geomagic, research triangle park, nc, usa). before performing best - fit alignment, unnecessary portion of the imported image except internal surface was eliminated. best - fit alignment is the arranging process via matching repeatedly the closest points of corresponding images in the virtual space on the program, and permits to measure morphologic differences in form.17 in this study, 300,000 to 600,000 random points were used for this alignment. after best - fit alignment procedure, the images of t1 and t2, t2 and t3, and t1 and t3 within each storage group (w and d) were compared, and the results of surface matching in storage group w and d were named as group wa, group wb and group wc, and group da, group db and group dc, respectively, in each upper and lower denture bases. as a result, 7 color - coded maps were created in each image group (table 1). when 3d compare was conducted, the maximum and minimum nominal values were set at 0.05 mm and the maximum and minimum critical values were set at 1.0 mm. on color - coded map, positive deformation that represent internal surface of the test model (the latter) was located above that of the reference model (the former) was expressed in the red to yellow color segments and negative deformation that represent internal surface of the test model was located lower than that of the reference model was expressed in color from cyan to deep blue. for evaluating the deformation pattern in detail, cross - sectional 2-d comparison was also performed. cross sectional view was created in med - palatal area (sagittally) and posterior molar area (frontally). statistical analyses were performed by ibm spss (spss v.22, ibm corp., armonk, ny, usa). the median, inter - quartile range, the maximum and minimum values of the positive and the negative deformation were measured. for evaluating differences between groups, these data were statistically compared at 95% significance level using kruskal - wallis test and mann - whitney u test for post hoc analysis. generally, when evaluating 3d deformation of denture base in upper denture bases major deformation pattern could not be seen in group w according to the elapse of time. also, in lower denture bases, major and repeating deformation could be seen in group d. figure 1, 2 represent the typical case of the color - coded map of groups and shows deformation pattern of both storage groups of upper denture bases, and figure 3, 4 represent deformation pattern of both storage groups of lower denture bases. in the water storage group, although little deformation was observed at some area of all groups, area of deformation was very small and any repeated or specific pattern was not found (fig. 1, fig. when compared between first 2 weeks, deformation was found in the bilateral posterior buccal flange area (yellow) which means decrease in distance between posterior flanges, and also found in posterior palatal seal area (cyan) which means negative deformation was occurred in that area. however, when compared between second 2 weeks, significant deformation pattern was reduced. therefore, results of color - coded map of subgroup mda and mdc showed similar pattern (fig. these findings were repeatedly confirmed with results of 2 d compare procedure. in the dry - stored group of lower denture bases, more obvious deformation was observed at posterior buccal flange area (cyan) and buccal shelf and retromolar pad (yellow) than in water - stored group. result of kruskal - wallis test demonstrated that there are no significant differences in overall, positive, and negative deformation among subgroups in both maxillary and mandibular water storage group (table 2 and table 3). in the maxillary dried storage group, there were significant different between subgroups and mann whitney u test was performed. (table 4) when overall deformation between subgroups was compared, significant differences were found between mda (median : 0.040 mm) and mdb (median : 0.000 mm), and also between mdb and mdc (median : 0.040 mm). when positive deformation was only concerned, statistical results were similar with that of overall deformation (median of mda : 0.032 mm, median of mdb : 0.017 mm, median of mdc : 0.039 mm). however, when negative deformation was compared, there are no significant differences among subgroups. in the mandibular dried storage group, likewise, no significant difference was found in positive, negative and overall deformation among subgroups (table 3). the median, interquartile range, maximum and minimum values, of overall, positive, and negative deformation of denture bases for all groups were presented in figure 5, and figure 6. it is obvious that the denture fabricated with a great care would be secured to patient 's comfort, retention and stability of denture depending on the intimate contact between denture base and its basal tissue. however, to wear the denture longer and maintain good oral health, minimizing unexpected distortion of the denture is also an important factor as much as fabricating denture precisely. thus, once the denture was fabricated precisely, maintaining of its accuracy would be a key factor for the longevity of denture. pmma is the most popularly used denture base material, and heat curing resin has some advantage such as less deformation after fabrication and better color stability compared to self - cured resin. however, among various molding methods, no method is free from dimensional deformation due to polymerization contraction, heat contraction, stress deformation, and water absorption, and compression molding is still frequently applied to fabricating denture. therefore, heat - cured resin and compression molding method was utilized in this study. upon polymerization of resin, monomers contract as much as 21 vol%, so total contraction would be estimated about 5 to 7 vol% because monomers constitute 25% of the total volume.4 in the previous study, regarding the influence of cooling time, more linear deformation was observed in fast cooling group compared to slow cooling group. the reported reasons were, inadequate time to compensate contraction by water absorption, and lack of emission of stress inside the denture base caused during curing.18 thus, this study was conducted after slowly cooling the denture bases for 24 hours in water. many previous studies were conducted for evaluating the deformation occurred in the denture base and its fitting accuracy. majority of previous studies employed optical microscope for measuring distance between landmark points of dentures, and some of those were conducted by using simple calipers.1920 these methods were limited for the overall deformation because measuring the two points was merely linear analysis. from the results and statistical analyses of this study, the fact that no significant deformation was observed during water storage resembles that of previous studies. some previous studies reported expansion was occurred during water storage due to the water absorption. expansion in the previous studies means increase in dimension, yet in this study, contraction was defined as the test surface being above the reference surface, and expansion was defined as being below the reference surface. in the study concerning the water absorption of acrylic resin, it was observed that 0.42% of expansion was observed over 3 weeks, and it takes about 17 days to be completely saturated.21 however, when water percentage was measured with digital scale and calculated with weight ratio, water percentage of 1.66 - 1.77 mass% was observed at deflasking, and water storage increased water percentage by only 0.46 - 0.50 mass%, indicating that high water percentage was already reached at deflasking.6 in the group of upper denture bases in water storage, no significant difference according to the storage period was observed. as the result from color - coded maps of overlapping week 0, 2, and 4, no significant changes could be observed. this could suggest that after the procedure of flasking, curing, deflasking, cooling, denture bases were already saturated with water that water storage after deflasking had no big influence on dimensional deformation since movement of water molecules is ignorable. in the group of upper denture bases in dry storage, week 0 and 2 showed significantly big difference in positive deformation (p =.026) and overall deformation (p =.011) compared to those of week 2 and 4, and week 0 and 4 also showed significant difference in positive deformation (p =.007) and overall deformation (p =.038) compared to those of week 2 and 4. this was the result of evaporation of water diffused into resin molecules, and more deformation took place during the first two weeks, indicating that most of the contraction occurred at that time. it can be said that deformation increases by time. upon observing deformation patterns with color - coded map, most contraction occurred at bilateral posterior buccal flange area somewhere between the week 0 - 2 and week 0 - 4, and as a result, the distance between the flanges decreased. the reasonthat significant deformation could not be seen in lower denture bases is thought that lower denture bases have broader surface than upper denture base, therefore enough water sorption could occur until deflasking. deformation patterns could be observed more clearly with two - dimensional analysis. in upper denture bases, at the sagittal section of the image, no repeating deformation patterns were observed except for expansion at posterior palatal seal, but more clear and repeated bilateral contraction was seen at the frontal section. in this way nowadays, it is possible to analyze denture bases at a virtual space using digital scanner and computer software.16 to measure an object 3-dimensionally, contact and non - contact types are present, and basically, contact type has excellent accuracy, but is more appropriate to measure narrow area such as teeth, than to measure broad area such as denture bases. optical laser scanner used in this study is 2-axis type with z axis on rotating plate and y axis at swing arm, and the scanned data was saved as stl file to digitalize. in other studies of analyzing discrepancies 3-dimensionally, performed surface overlap alignment after placing reference points at specific places, such as palatal portion of denture, alveolar ridge crest or cusp tip.1620 however, these techniques need assumption that no deformation occurs at the reference points during curing or storage, but there is no proof of it. therefore, best - fit alignment can be utilized to minimize the errors of comparing and analyzing two denture bases, because this method uses scanned data of the whole surface.17 through this study, the overall deformation and its pattern in cured upper and lower denture bases in dry and water storage was compared 3-dimensionally and analyzed in timely manner. to further evaluate the clinical effect, experiment protocol and program development is required to evaluate the adaptation of oral tissue and denture base. in addition, long - term and intensified studies are required to evaluate dimensional deformation during curing, deflasking and storage as they can be evaluated in 3-dimensional manner. following conclusions were attained from this study. during dry storage of upper denture bases, significant deformation was observed as time passed from week 0, 2, to 4. it occurred mostly in first two weeks, contraction was observed at bilateral posterior flange, and expansion at posterior palatal seal region. although no significant differences were found in both storage of lower denture bases, obvious 3d deformation pattern were observed in dry storage denture bases, contraction at posterior buccal flange area and expansion at buccal shelf and retromolar pad. | purposethe aim of this study was to evaluate whether there is any typical deformation pattern existing in complete denture when it was dried by using the 3d scanner and surface matching program.materials and methodsa total of 28 denture bases were fabricated with heat curing acrylic resin (each 14 upper and lower denture bases), and 14 denture bases (each 7 upper and lower denture bases) were stored in the water bottle (water stored), and another 14 denture bases were stored in the air (dry stored). each specimen was scanned at 1st day after deflasking, 14th day after deflasking, and 28th day after deflasking, and digitalized. three dimensional deformation patterns were acquired by comparison of the data within storage group using surface matching program. for evaluating differences between groups, these data were compared statisticallyusing kruskal wallis and mann whitney - u test (=.05).resultswhen evaluating 3d deformation of denture base, obvious deformations were not found in maxillary and mandibular water storage group. however, in dry stored group, typical deformation pattern was detected as storage time passes. it occurred mostly in first two weeks. major deformations were found in the bilateral posterior area in both maxillary and mandibular group. in maxillary dry stored group, a statistical significance was found.conclusionit was proved that in both upper and lower denture bases, dry storage caused more dimensional deformation than water storage with typical pattern. |
each year, 13 million or nearly one quarter of all deaths worldwide result from preventable environ - mental causes relating mainly to water, sanitation and hygiene ; indoor and outdoor pollution ; harmful use of chemicals such as pesticides ; and climate change16. these risk factors, which are both avoidable and preventable, play a role in more than 80 per cent of diseases that are routinely reported to the world health organization. children, especially from poor families are most vulnerable to illness and death due to these diseases. however, simple and cost - effective interventions are available, which, if implemented early and effectively, can prevent most of these deaths. the earthquake followed by a tsunami in japan 's fukushima daiichi on march 11, 2011 is considered as one of the greatest nuclear and environmental disasters in human history. the 2010 floods, the worst in the history of pakistan killed more than 1500 people. during 2010 - 2011, unprecedented floods also took a heavy toll of life in ladakh, northern india as well as in cities of melbourne, australia and rio de janeiro, brazil. the long - standing health problems associated with ground water contamination with arsenic and fluoride in parts of india are examples of the health consequences associated with environmental risk factors7. the factors including globalization, rapid industrialization, urbanization, unplanned and unregulated development activities, increase in transport, over - dependence on pesticides in agriculture, and climate change indicate that the negative health consequences associated with environmental causes are likely to worsen in the future, unless action is taken urgently. recent studies and systematic reviews indicate that the environmental factors are responsible for an estimated 24 per cent of the global burden of disease in terms of healthy life years lost and 23 per cent of all deaths2. while 25 per cent of all deaths in developing countries are attributable to environmental factors, only 17 per cent of deaths in the developed countries are due to such factors. children are the worst sufferers of the adverse impact of environmental risks, as an estimated 24 per cent of all deaths in children under 15 are due to diarrhoeal diseases, malaria and respiratory diseases, all of which are environmentally - related2. it is also evident that much of the disease burden is attributable to a few critical risk factors (table and fig.). these include unsafe water and sanitation, exposure to indoor smoke from cooking fuel, outdoor air pollution, exposure to chemicals such as arsenic, and climate change. unsafe water, sanitation and poor hygiene contribute to a large number of deaths, estimated at about 0.45 million in india alone. environmental risk factors and the diseases contributed diseases and the fraction attributable to environmental risk factors. while good progress has been made with respect to drinking water availability, the situation in many countries of asia relating to sanitation continues to remain bad. currently, 2.5 billion people lack sanitation facilities, with coverage being poorest in south asia ; as many as 629 million population in india is without sanitary facilities. according to unicef, 67 per cent of the rural population in india still practice open defecation89. among some countries of the south - east asia region namely bangladesh, bhutan, sri lanka, and india, the proportions of population without access to sanitation during 2010 were 44, 56, 8 and 66 per cent, respectively3. the progress in the region as a whole has been slow - from 34 per cent with sanitary facilities in 2000 to 43 per cent in 2010. given this situation, it is clear that mdg 7 relating to water and sanitation is unlikely to be met by 2015. the link with disease is clear as unsafe water and sanitation contribute to 94 per cent of the diarrhoeal disease burden. unfortunately, drinking water and sanitation have not received the kind of political commitment these deserve although the benefits can go beyond health and economic development and to enhance personal and national dignity. assigning the highest priority including allocation of appropriate resources and fully integrating water, sanitation, and hygiene in disease reduction strategies is therefore, an important priority and an essential prerequisite for national development. among the south - east asia region countries, only nepal has higher proportion (69%) of population without access to improved sanitation than india3. each year, an estimated 42 per cent of lower respiratory tract infections or pneumonia are associated with indoor and outdoor pollution including second hand - smoke10. long - term exposure to suspended particulate matter from indoor burning of solid fuel such as wood is a major cause of respiratory diseases such as pneumonia, asthma, chronic obstructive lung diseases (copd) especially among children1113. according to who, outdoor air pollution contributes to 800, 000 deaths each year globally and about 60 per cent of them are in asia, caused by domestic consumption of fuel, motor vehicles especially those running on diesel, industries and burning of all kinds of waste2. these factors together with second - hand smoking are leading to ischaemic heart disease, acute respiratory infections, asthma, and lung cancer. for example, construction of the aswan dam in egypt led to an increase in malaria and schistosomiasis. it is estimated that about 42 per cent of malaria occurring in asia and africa is attributed to environmental factors such as land use, deforestation and water resource management16. similarly, growing rice crops, pig rearing, vector breeding and exposure to unsafe water all play an important role in transmission of acute encephalitis syndrome which, in 2011 alone accounted for 6800 cases and 820 deaths, mostly children below 15 yr, with the epicenter in the state of uttar pradesh, india (dr a.k. the environmental factors contribute greatly to the impending pandemic of dengue as well as to transmission of schistosomiasis in many countries including china and indonesia. of the 12.7 million cases each year, 19 per cent are estimated to be attributable to the environment17. the second most common cancer - stomach cancer due to helicobacter pylori infection is associated with poor sanitation and overcrowding conditions where the poor live. recently, many reports indicate an increasing incidence of cancer in agricultural heartland of punjab1819 and suggestions have been made of a possible link with environmental causes, such as use of pesticides which have been found both in water and soil. exposure to indoor smoke from solid fuel or tobacco smoke or by smog can trigger an asthma attack, especially during winter20. in many cities in india and elsewhere this has resulted in a major increase in the number of children consulting health care workers for asthma. in one study carried out in new delhi, india, hospital emergency room visits for asthma and chronic obstructive lung disease increased by 21 and 24 per cent due to high levels of ambient air pollution21. with regard to the prevalence of copd which is clearly linked with environmental factors, the rates seem to vary between countries due to the level of environmental risk factors. more than one - third of deaths due to copd, are attributable to environmental causes. reports on the hazard of ground water pollution in india date back to 194522.23. today, 30 per cent of urban and 90 per cent of rural households in india depend on untreated surface or ground water and this causes an enormous adverse health impact in many areas24. two examples of a serious health situation due to contamination of ground water used for drinking purposes are of particular concern24. more than 60 million people living across 20 states of india are exposed to fluoride contamination (more than 1.5 mg / l) and are at risk of serious health effects, ranging from dental fluorosis to crippling skeletal fluorosis, both conditions being irreversible. bone deformity results from an excess fluoride content in water which prevents absorption of calcium, essential for bone development. high concentration of arsenic in ground water is a major public health problem in west bengal affecting nearly 50 million population. in bangladesh, the arsenic problem is considered as a public health emergency - the largest poisoning of a population in history25. arsenic contamination has been detected in 59 of the 64 districts and 249 of the 463 sub - districts in bangladesh. estimates suggest that a quarter of the 6 - 8 million tube wells in bangladesh may contain arsenic levels more than 50 ppb or 0.05, estimates indicate that between 30 - 40 million people are at risk through exposure from arsenic in drinking water. arsenic can cause severe and irreversible health effects, even at low levels of exposure and over a prolonged period of time. the symptoms can start at childhood and with continued exposure get increasingly worse. besides skin diseases such as hyperkeratosis, death due to cancer in addition, environmental conditions make south asia prone to disasters and public health emergencies such as floods and earthquakes which cause much suffering and economic loss. the situation is likely to get worse due to climate change and the health impact is likely to be serious for poor people living in developing world especially in asia and africa2830. it will lead to an increase in vector - borne and water - borne diseases, heat stroke, asthma, cardiovascular diseases, and threaten food security by causing more floods and drought. while reducing greenhouse emissions is an individual responsibility, urgent action at adaptation is necessary by strengthening surveillance and response capacities in the countries to enable them to be resilient in coping with the adverse impact of climate change. besides the environment, these include socio - economic factors, prevailing customs and traditions as well programmes and policies, and the access and use of health services by the affected communities. the paucity of such information at the national level remains a major constraint for advocacy. to fill this information gap, environment and health impact assessments can help in systematically identifying the policies, programmes or developmental activities that are likely to have a major impact on the health of the local population. such information can make a critical input for deciding on the right policies and projects. assessment is a multi - disciplinary approach in which a combination of methods is used to obtain qualitative and quantitative data preferably using a check list. such an assessment can also identify the risk factors that can lead to health problems in relation to such activities as construction of buildings, transport systems, housing, energy, industry, urbanization, water, nutrition, etc. the data so obtained can help guide decision makers while planning and implementing such policies, programmes and development projects. such information can also help all relevant sectors and local bodies to (i) understand health consequences of various projects, (ii) keep health in mind while planning and implementing new projects and agree to the concept of health in all policies as a guiding principle, and (iii) finally ensure that the health of the local population is safeguarded while engaging in a new project or development activity. it is clear that environmental factors will continue to have an impact well into the future and, in fact, the situation is likely to get worse. a few strategic approaches are highlighted below that can help mitigate the health problems arising from environmental causes and to meet the challenge of health and environment : (i) developing an evidence - base for action : there is, at present a paucity of information on the environmental health impact in the countries, the transmission pathways, and on the populations at risk. more detailed and precise data on the health impact relating to water, air, food, and climate which could help in setting priorities and developing appropriate national policies are needed. more focused research is needed to understand the environmental factors, and their impact on economic development and on the daily lives of the people. a national database on health and environment can help establish and monitor the relationship between the distribution and trends of various diseases associated with environmental risk factors, the areas which are vulnerable and where risks are high, and the populations having the greatest need for environmental and health interventions. a mechanism for collecting and sharing information on environment and health and on country experiences could be useful. best practices in india such as use of plastics for road construction work, and levying green tax on vehicles entering manali and using it for environmental protection in himachal pradesh, provision of gas cylinders to populations in uttarakhand so that they do not have to go to the forest for firewood and thereby protecting the forest cover, solar energy expansion in gujarat, total sanitation programme in states such as haryana, sulabh experience in technical innovation in low cost toilets, ban on gutka and pan masala by madhya pradesh and seven other states in india, constructing ecological latrines in nepal and many such examples could be shared through an information clearing house. (ii) strengthening national environmental health policy, strategy and infrastructure : to address issues relating to health and the environment requires a comprehensive and inter - sectoral approach through preparation and implementation of a national environment and health action plan (nehap). supported with data from the environment and health impact assessment, a working group with representatives from the environment, health and other sectors can identify priorities which can then be adopted by the ministries of health and environment. the plan, along with and allocation of adequate human and financial resources if implemented seriously and on a sustained manner, can go a long way to mitigate the problem emanating from the interaction between the environment and health. a national advisory board on environment and health can help advise and periodically monitor implementation of the plan. strengthening physical infrastructure such as provision of safe drinking water supply, functioning sewage treatment system, availability of non - polluting fuel for motor vehicles, clean cookstoves, biogas and solid waste management are responsibilities that national and local governments must take seriously and urgently. proper allocation of resources for such services if demanded by the general population can become a priority for decision makers. (iii) sustaining inter - sectoral co - ordination and partnerships : most environmental risk factors lie outside the health sector, the action to protect human health therefore, cuts across various sectors such as the government sector namely ministries of environment, agriculture, transport, energy, urban development, water resources and rural development, as well as the private sector. currently in many countries a broad - based, high - level national steering committee represented by various relevant government ministries, civil society including non - governmental organizations, the private sector and chaired by the highest level of government meeting at regular intervals could help mobilize all sectors and ensure a co - ordinated implementation of nehap. many programmes are presently underway that deal directly or indirectly with health and environment. there is a need to bring synergy among these programmes such as diarrhoeal disease control, water and sanitation, non - communicable diseases, etc. an overarching mechanism for functional collaboration among various programmes could assist in joint planning, decision making on priorities, and on deciding on activities to monitor. (iv) augmenting public participation and social mobilization : protecting the environment is every citizen 's responsibility. to keep the environment clean now and for future generations, it is necessary to enlist support from the public to safeguard fresh water sources, observe good sanitary practices and personal hygiene, and discourage all actions that harm the environment. the media and community - based organizations have an important role to play in creating public awareness in both urban and rural areas. while the former can reach a large section of the population with health messages using electronic or print media, community - based organizations can use an interpersonal approach and facilitate behaviour change. a social movement is needed to discourage traditional practices such as open defecation, throwing garbage including plastic bottles and bags on the road, and burning of all kinds of waste ; and promote practices such as hand washing and personal hygiene, reducing, reusing and recycling items such as papers, using only eco - friendly and biodegradable materials, promoting the use of public transport, planting more trees, and avoiding second - hand smoke. (v) the stewardship role of health and capacity building : health has a critical role in advocacy and in mobilizing and supporting other sectors to contribute in the area of health and environment. in order to do so, leadership skills of health professionals must be built in negotiating with other relevant sectors to play their role in protecting the environment and health. the health sector could also take a lead in carrying out health impact assessments and advise other sectors in developing policies that protect human health. in addition, health professionals, civil society and other stakeholders need to be periodically re - oriented on environmental health issues and priorities. the environment has a major impact on health and investing in environmental health is certainly a good investment. rapid urbanization, industralization, globalization and an increasing population is putting further stress on the environment. if strategic actions are not taken urgently by all sectors, the problem is likely to worsen thereby impacting human health directly. given that the environment is closely linked with each of the eight mdgs, without priority being assigned to interaction between environment and health, it will be a challenge to achieve mdgs. the future of the planet now rests solely on what we decide and do today. | a substantial burden of communicable and non - communicable diseases in the developing countries is attributable to environmental risk factors. who estimates that the environmental factors are responsible for an estimated 24 per cent of the global burden of disease in terms of healthy life years lost and 23 per cent of all deaths ; children being the worst sufferers. given that the environment is linked with most of the millennium development goals (mdgs), without proper attention to the environmental risk factors and their management, it will be difficult to achieve many mdgs by 2015. the impact of environmental degradation on health may continue well into the future and the situation in fact, is likely to get worse. in order to address this challenge, two facts are worth noting. first, that much of the environmental disease burden is attributable to a few critical risk factors which include unsafe water and sanitation, exposure to indoor smoke from cooking fuel, outdoor air pollution, exposure to chemicals such as arsenic, and climate change. second, that environment and health aspects must become, as a matter of urgency, a national priority, both in terms of policy and resources allocation. to meet the challenge of health and environment now and in the future, the following strategic approaches must be considered which include conducting environmental and health impact assessments ; strengthening national environmental health policy and infrastructure ; fostering inter - sectoral co - ordination and partnerships ; mobilizing public participation ; and enhancing the leadership role of health in advocacy, stewardship and capacity building. |
it is now well recognized that obesity and asthma are epidemiologically linked [14 ]. such a relationship is also seen between asthma and other markers of the metabolic syndrome such as insulin resistance and hypertension that can not be accounted for by increased body mass alone [47 ]. while both obesity and asthma are individually associated with an increased state of inflammation, interestingly, in obese asthmatics, there is a dissociation between cellular inflammation and severity of symptoms, especially in women [9, 10 ]. this discordance would suggest that while obesity - related systemic inflammation can certainly be one mechanism for increased asthma risk, there is a need to examine mechanisms independent of cellular inflammation that may play a role in asthma in the context of conditions such as obesity and metabolic syndrome. a number of cellular signaling and metabolism mechanisms could contribute to increased asthma risk in patients with obesity and/or metabolic syndrome. considering the fact that altered glucose metabolism occurs in both cases, and hyperinsulinemia with reduced insulin sensitivity is involved, an obvious potential factor affecting the lung is insulin itself, particularly a direct effect on structural cells as well as immune cells in the airway. in a large danish cohort, it was observed that insulin resistance (ir) was more strongly related to asthma risk than any of the anthropometric parameters. while this study did not specifically examine serum insulin, independent of blood glucose or diabetes, it is recognized that insulin resistance (ir) and consequent hyperinsulinemia are central molecular pathologies in the genesis of the metabolic syndrome [12, 13 ]. other markers of metabolic syndrome such as c - reactive protein and correlates such as hyperglycemia, diabetes, or hypertension have all been associated with reduced lung function, asthma, or even copd, in large clinical studies. yet if insulin excess can directly alter lung cellular physiology, this would represent a fundamental common molecular link between asthma and the cardiometabolic syndrome. this review focuses on the current stage of knowledge regarding the direct effects of insulin in lung cells in the context of airway remodeling and hyperresponsiveness. here, it is important to emphasize that in fact there is a significant knowledge gap regarding insulin effects in the airway, and we therefore draw upon what is known in other cell types to generate hypotheses that could drive future research. certainly, our focus on insulin does not rule out several other potential mechanisms such as dysfunctional arginine metabolism and uncoupling of nitric - oxide synthase (nos) by increased asymmetric dimethyl arginine (adma), effects of adipokines, and direct mechanical effects of thoracoabdominal obesity on lung mechanics. insulin is one of the central homeostatic hormones with global effects that extend beyond glucose and lipid metabolism. as a pleiotropic hormone, insulin effects range from the well - known hypoglycemia to regulation of cell growth and differentiation [19, 20 ]. insulin regulates a number of key metabolic biological processes such as stimulation of glucose uptake, lipid synthesis, oxidation, storage of fat, and cell proliferation [2123 ]. insulin - mediated signaling varies significantly between cells and tissues necessitating an understanding of its actions in the context of the lung and in specific cell types within the lung. insulin resistance (ir), that is, reduced responsiveness to insulin in liver, muscle, and adipose tissue, is closely associated with various metabolic diseases such as obesity, metabolic syndrome, nonalcoholic fatty liver disease, and type 2 diabetes mellitus. since ir in key metabolic tissues is associated initially with compensatory hyperinsulinemia, insulin - related effects that retain sensitivity in other tissues this is a partial reflection of distinct physiological processes in multiple organs and is important because ir is also associated with other putatively nonmetabolic diseases such as asthma [4, 27 ] and some cancers [2832 ]. while relative deficiency of insulin and hyperglycemia are well studied in diabetes, the harmful effects of insulin excess are poorly recognized except where they result in hypoglycemia. importantly, given the cell- and tissue - specific heterogeneity in insulin signaling and the potential confounding role of disease states per se, effects on other tissues may not be easily extensible to the lung. nonetheless, considerable insight into potential mechanisms by which insulin influences lung cellular components relevant to asthma may be gleaned from such prior data. expression of insulin receptors in the lung has been verified ; however, their role has only been partially characterized using crude membrane of normal lung as well as plasma membrane fractions of lung tissue. importantly, interaction of these receptors with insulin appears to be time and temperature dependent, and furthermore rapid, saturable, and highly reversible [34, 35 ]. the relevance of these findings is that insulin has the potential to dynamically influence lung structure and function at various life stages and thus modulating asthma predisposition. insulin receptors are important during lung development with lung epithelial cells abundantly expressing insulin receptors during the pseudoglandular stage with receptor levels decreasing during later stages of development. assuming that maternal insulin is the agonist, these data fit well with prior evidence that maternal diabetes has substantial growth effects on fetal lungs. others have shown that high insulin levels delay lung development in fetuses of diabetic mothers by inhibiting surfactant protein a (sp - a). inhibition of sp - a and sp - b genes ' expression leads to increased incidence of respiratory distress syndrome (rds) in infants of diabetic mothers. in a large canadian study, what is less clear, but is likely, is whether these diabetic mothers had hyperinsulinemia. furthermore, alternative mechanisms may be at play, including hyperglycemia, and altered cytokine / adipokine milieu. while these clinical associations are clear, there is limited experimental evidence supporting a direct role for insulin per se in lung development. in cultured lung epithelial cells, insulin reduces vegf expression and transcriptional activity of hif-2 on vegf promoter in an mtor - dependent manner. the importance of the akt - mtor pathway in lung epithelium relates to the pathogenesis of infant rds which predisposes towards asthma later in life. animal models of hyperinsulinemia are more complex with at least one report of accelerated fetal lung maturation in pregnant rabbits by a two - day intravenous (iv) infusion of insulin, but with significant hypoglycemia. accordingly, it is difficult to conclude whether insulin is promaturation when it comes to lung development, and here it is important to consider whether the timing of high versus low level of insulin receptor expression and activation is a confounding factor. other than effects of insulin on developing lungs, recent efforts towards developing inhaled insulin formulations for diabetes management have provided interesting insights into direct effects of insulin on the mature lung. since the pulmonary epithelium and the surfactant that lines the alveoli (0.1 - 0.2 m thick) constitute physical barriers to pulmonary absorption, local deposition and action of insulin are to be expected. locally high concentrations of protease inhibitors and acidic formulations seem to protect the insulin peptide from membrane - associated cells and intracellular proteases [4345 ] resulting in much of the inhaled insulin being absorbed systemically in the alveolar region. however, despite good systemic delivery, there also appears to be substantial local effect of inhaled insulin. for example, inhaled insulin in diabetic patients is associated with a decrease in forced expiratory volume in 1 second (fev1) [46, 47 ], but the mechanisms are not clear. certainly, insulin can shift t cells towards a th2-type response, known to be a key event in the pathogenesis of asthma. it has also been observed that insulin, via activation of pi3k pathway, promotes mast cell survival and degranulation, which facilitate bronchoconstriction. nonspecific proinflammatory effects via activation of pulmonary macrophages are also possible, and in some studies it has been shown that inhaled insulin may deposit at air - tissue interfaces with characteristics of amyloid aggregates. the relevance of these findings may be in that inhaled formulations of insulin that were once promising, approved strategies for treatment of diabetes mellitus in us and europe [51, 52 ] have been withdrawn due to persistent reports of respiratory problems, including cough. on the other hand, it appears that insulin also has anti - inflammatory effect in the context of severe th1-type inflammation. insulin has been found to reduce levels of inflammatory cytokines, attenuate acute lung injury and systemic inflammatory response, and promote survival in rodents exposed to lps. collectively, these limited data again suggest a dichotomous role for insulin where increased levels of insulin in the mature (adult) lung have found to be detrimental on the one hand but protective on the other. what is important to determine is whether systemic hyperinsulinemia as occurring in metabolic syndrome leads to pathophysiological changes leading to asthma, or is protective, and the mechanisms by which insulin acts on the airway. while asthma is usually defined as an inflammatory disease, a cardinal feature is airway hyperresponsiveness (ahr) : excessive narrowing of airways in response to normal constrictive stimuli. ahr is associated with increase in airway smooth muscle (asm) mass, dysfunction of bronchial epithelium, and alterations in extracellular matrix (ecm) within the airway wall. increased asm mass is considered to play a key role in the development of ahr and activate epithelial mesenchymal trophic unit (emtu) that leads to airway remodeling. as a growth factor, the contribution of insulin to increased asm mass and/or contractility in the context of asthma is obviously important. noveral and colleagues first showed that functional insulin - like growth factor-1 (igf-1) receptors are present on rabbit asm and that their stimulation is sufficient to induce asm proliferation [56, 57 ]. these studies have been replicated in other animal model systems, and the pathway was determined to be activation of the map kinase system. it is well known that insulin and igf-1 can crossactivate each other 's receptors (insulin receptor (insr) and igf1r) and that there is also significant crosstalk downstream to these receptors via the insulin receptor substrate proteins (irs ; figure 1). it has been subsequently shown that high levels of insulin promote asm contraction and enhance contractile responses to methacholine and kcl [60, 61 ]. these effects have been reported to occur via rho kinase- and pi3 kinase - dependent signaling pathways [62, 63 ]. other reports suggest that insulin increases ecm proteins such as laminin (a2, b1, and g1 chain expression) which are important in lung growth and differentiation of nave mesenchymal cells, leading to hypercontractile and hypoproliferative asm [65, 66 ]. furthermore, limited studies suggest that aerosol administration of insulin leads to asm contraction but indirectly via production of procontractile prostaglandins that involve rho kinase. overall, the data so far suggests that, if anything, insulin effects on asm are likely to result in increased airway contractility, cell proliferation, and fibrosis, all of which should lead to a thicker, stiffer, and hypercontractile airway reflective of an asthma phenotype. however, it is also important to recognize that much of the work has been in vitro, with high levels of insulin, typically applied for relatively short periods. whether prolonged hyperinsulinemia and/or activation of insulin receptors leads to different cellular effects in the airway, and whether such effects are reversible (in the context of therapy) remain to be determined pi3k / akt signaling has a central role in the conserved downstream pathway of insulin signaling [68, 69 ] and is an important regulator of diverse array of cellular events, including cell growth and cell survival in a number of cell types. several studies have validated the functional significance of the pi3k pathway in glucose homeostasis and shown that pi3k inhibition leads to insulin resistance [71, 72 ]. it has been also shown that insulin is a potent activator of pi3k in human bronchial epithelial cells and inhibits tlr3 mediated apoptosis. it has been also shown that insulin, via activation of pi3k pathway, promotes mast cell survival and degranulation, which may leads to bronchoconstriction. this pathway is also thought to be important at least in prenatal lung development in the context of maternal diabetes where fetal hyperinsulinemia in response to maternal hyperglycemia [7477 ] results in pi3k / akt1/mtor activation and induces rds. also, as mentioned previously, high levels of insulin through the pi 3-kinase signaling pathway may also inhibit surfactant protein production expressed in the lung epithelial cells and lung maturation [37, 79, 80 ], thus predisposing the immature lung to airway diseases later in life. while these data relate to the developing lung, the relevance of the enhanced pi3/akt signaling also lies in its well - recognized role in adult asthma. for example, loss of function mutations in the principal inhibitory phosphatases ship, pten, and inpp4a, are associated with asthma, and knockdown of inpp4a induces airway remodeling and hyperresponsiveness. activation of the pi3/akt pathway promotes survival of airway epithelial cells as well as asm and conversely can enhance proliferation, thus contributing to airway remodeling. whether insulin activation of pi3k / akt is involved in this regard is not currently known. however, insulin has been shown to act via pi3/akt to inhibit epithelial apoptosis that normally occurs with viral exposure and could thus promote airway remodeling in this context (figure 2). some studies have also reported insulin regulation of wnt/-catenin pathway and stimulation of transcription of lef / tcf - dependent genes via activation of pi3k / akt and ras signaling pathways which normally inhibit gsk3- and activate the -catenin pathway in hepatocarcinogenesis. dysregulation of wnt/-catenin pathway influences many biological processes, including cell fate decisions, stem cell proliferation, and axis specification [8588 ]. while relationships between insulin and wnt/-catenin have not been reported in the lung per se, wnt/-catenin pathways are increasingly recognized as being important in regulation of lung cell proliferation and differentiation. -catenin is required for normal lung morphogenesis, and deletion of -catenin during critical periods of lung development leads to blocked alveolar epithelial cell differentiation and disruption of alveolar formation. furthermore, conditional activation of -catenin in respiratory epithelial cells leads to altered epithelial cell differentiation by induction of alveolar marker prosurfactant protein c (sp - c) and causes goblet cell hyperplasia, air space enlargement, and pulmonary tumors. thus, -catenin signaling pathway has a critical role in the differentiation of the respiratory epithelium in the postnatal lung. accordingly, even during lung development, insulin could potentially promote morphogenesis via activation of the wnt/-catenin pathway, although it would be important to determine whether the relative timings of insulin versus wnt/-catenin activation are detrimental or beneficial. in the adult airway, activated -catenin-/tcf-/lef - dependent gene transcription of vegf, matrix proteins such as fibronectin and versican, and proinflammatory enzymes / mediators such as cyclooxygenase (cox)-2 and interleukin (il-8) suggest the involvement of this pathway in regulation of inflammation and airway remodeling. here too, insulin - mediated activation of -catenin signaling could be involved in airway disease pathogenesis. while there is currently no information in the context of asthma per se, data from fibroproliferative lung diseases may be suggestive where activation of -catenin signaling is involved. inhibition of gsk3 and stabilization of -catenin is governed by tgf- signaling and leads to altered ecm. of relevance, diabetes and metabolic syndrome have been associated with increased risk of idiopathic pulmonary fibrosis and copd [95, 96 ]. whether insulin per se plays a role in these diseases is not known, but if so, modulation of wnt signaling pathway may be relevant. also, in other systems like the heart, akt - mediated gsk3 phosphorylation leads to increased -catenin expression and causes cardiac smooth muscle hypertrophy, whether this may be mirrored in the airway smooth muscle, remains to be determined. there is substantial data that mechanistically links insulin and insulin like growth factor-1 to lung development and function. it is conceivable but not proven that hyperinsulinemia may lead to development of lung disease, particularly asthma. | obesity, metabolic syndrome, and asthma are all rapidly increasing globally. substantial emerging evidence suggests that these three conditions are epidemiologically and mechanistically linked. since the link between obesity and asthma appears to extend beyond mechanical pulmonary disadvantage, molecular understanding is necessary. insulin resistance is a strong, independent risk factor for asthma development, but it is unknown whether a direct effect of insulin on the lung is involved. this review summarizes current knowledge regarding the effect of insulin on cellular components of the lung and highlights the molecular consequences of insulin - related metabolic signaling cascades that could adversely affect lung structure and function. examples include airway smooth muscle proliferation and contractility and regulatory signaling networks that are associated with asthma. these aspects of insulin signaling provide mechanistic insight into the clinical evidence for the links between obesity, metabolic syndrome, and airway diseases, setting the stage for novel therapeutic avenues targeting these conditions. |
the effect of cw laser light on the production of s and cl was studied. the s current was reduced by one order of magnitude with 100 mw of laser power. the sensitivity of accelerator mass spectrometry (ams) for a rare nuclide is limited by the ability to distinguish it from abundant neighboring masses and from atomic isobar interferences. molecular isobars, i.e. molecules with almost the same mass as the ion of interest, can be effectively removed by their break - up in the stripping process of a tandem accelerator. atomic isobars, i.e. atoms with almost the same mass, but from a nearby element, are more difficult to separate and typically require particle energies around 1 mev / amu. at these energies isobaric discrimination based on however, usability depends strongly on the available energy and on the relative difference in atomic number. heavy isobars like mn and cr can be separated only at two of the largest facilities worldwide, that operate at terminal voltages of 14 mv. to separate cl and s, energies of at least 30 mev the vienna environmental research accelerator (vera) is so far the only 3-mv - ams facility, where measurements of cl at natural isotopic levels can be performed, that are competitive to larger facilities. in fortunate cases, e.g. c or al, the stable atomic isobars do not form negative ions and are thus suppressed already in the ion source. the lack of atomic isobars in these ion beams has allowed a lowering of the terminal voltage into the 200 kv range instead of several mv. therefore, element - selective techniques have been investigated to suppress isobaric interferences in an ion beam prior to injection into the accelerator. recently, a sulfur - to - chlorine suppression factor of at least 10 was demonstrated using optical filtering via selective photodetachment in an ion cooler, which increased the interaction time of the ion beam and the laser beam. the other approach using resonant charge transfer in a no2-filled gas reaction cell yielded an even higher sulfur suppression of 10. both methods, however, require substantial modifications of the injection system of existing accelerators to adapt for an ion cooler or a gas cell. furthermore, total current throughput of both devices is limited to a few na, which is less than 1 of typical ion beam currents in ams measurements. in this paper. it does not give comparable high suppression factors but can be readily implemented at most facilities as an additional means for isobar separation. the method is based on optical interaction with the environment immediately in front of, or at the surface of the cathode in a cesium sputter negative ion source of the middleton type. it requires only a free optical path to the target and a high power laser. previous experiments with high power pulsed lasers, but different goals in mind, revealed interesting changes in the sulfur and chlorine production. in ams measurements of cl, the sulfur suppression by our new technique significantly reduces the s count rate in the detector. this is of interest for all facilities where the ion beam is injected into the detection setup without prior sulfur separation [1113 ] in order to achieve high efficiency. at vera, suppression of sulfur by one order of magnitude is sufficient to allow a reduction of the amount of sample material (agcl) required for a reliable cl measurement. furthermore, the method is beneficial for measurements of samples with isotopic ratios cl / cl < 5 10. experiments were performed at the gunilla facility of the university of gothenburg and at vera at the university of vienna using a new injector. in both experiments the same 1.2 w, 445 nm continuous wave diode laser was used. the corresponding photon energy of 2.79 ev lies between the electron affinities of sulfur (2.077 ev) and chlorine (3.613 ev)., we also investigated the effect of a 1064 nm (1.17 ev) laser with similar output power. the optical setup was almost identical at both facilities and is shown schematically in fig. 1. the laser beam entered the ion beamline through a borosilicate window and was directed by a set of four mirrors outside and one mirror inside the vacuum chamber. two apertures were centered on the laser beam path and positioned about 1 m apart. the mirror placed inside the vacuum chamber was covered by a glass plate with a transparent, conductive layer of ito (in2o3:sno2). this prevented the glass plate and the mirror from being charged by stray ions that unavoidably hit the mirror. the outside mirror situated in front of the first aperture was mounted in a flipping mirror mount. by flipping this mirror out of the optical path it was possible to optically observe the cathode and the hot ionizer using a theodolite. this ensured that the laser light hit the cathode when the flipping mirror was inserted in the beam path. fine tuning of the alignment was achieved by maximizing the effect caused by the laser on either the sulfur or the chlorine signal. the maximum laser power at the cathode position in a 1 mm 1 mm area was approximately 200 mw at gunilla and 400 mw at vera. the highest losses came from absorption in the ito coated glass plate (about 20% measured at 445 nm). the optical losses for both wavelengths were about 10% in the borosilicate window and about 5% in each mirror. around 500 mg of this material was pressed into a cylindrical cathode with 5 mm inner diameter. at vera the samples contained 220 mg agcl pressed into a copper cathode with agbr backing. since vera is an ams facility, only microscopic amounts of sulfur could be put into the ion source in order to avoid contamination in future measurements. most samples contained chemically cleaned agcl with a typical sulfur content of approximately 1 ppm. at gunilla hence, the time structure of the effect had to be studied consecutively for various isotopes. at vera, on the other hand, several masses can be measured almost simultaneously using offset - faraday - cups and particle detectors. here, the switching time between the different detectors allowed for several measurements per second. 2 shows a comparison of two mass spectra recorded with and without laser. an increase in chlorine current by a factor of 2 and a decrease in oxygen and sulfur currents by more than a factor of 5 were observed when approximately 100 mw of laser light was directed onto the cathode. the ion currents did not change immediately after switching the laser on or off. the time constants for the currents to adjust to a change in laser intensity were of the order of several seconds up to minutes. since we could not resolve atomic from molecular ions this is, however, unlikely since the measured isotopic abundances match the natural abundances of sulfur and chlorine isotopes. in particular, there was no observed excess at mass 32, indicating only little if any interference from o2. after sputtering the sample for more than an hour, the mass scans in fig. the ion source output was stable and the observed change in the ion currents of the elements is an effect of laser light and not an effect of sputter time. the measurements were repeated several times on the same sample giving sulfur suppression factors of 1020. thus, the estimated total cl current emitted from the source was of the order of 10 a, i.e. at the same level as at vera (see below). when the operational parameters of the ion source were varied, significant changes in the size of the effect could be observed. while the ionizer power given below may not be best suited to quantify ion source conditions, it is the only parameter directly accessible at the two facilities. generally, sulfur suppression worked best with low ionizer power of 7080 w, producing 510 a cl output. increasing the cl output to 40 a with 100120 w of ionizer power reduced the effect on the sulfur to chlorine ratio to approximately 1.5. even with constant operating parameters of the ion source, i.e. ionizer power, output current, cathode current and cesium oven temperature, the magnitude of the effect differed over time without obvious correlation to the sputter age of the cathode. therefore, we believe that other source parameters, which could not be measured in the current apparatus, played an essential role. this could be, for instance, the cesium vapor pressure, the sample surface temperature or the cesium coverage on the sample. thus, the observations are hard to disentangle and they can not be attributed to a particular parameter. the dependence of the effect on the laser power was also investigated. 3. already as little as 8 mw laser power at the cathode induced a noticeable change in the sulfur output. the data shows a quadratic behavior of the sulfur reduction as a function of the laser power. we also observe a peculiar effect when the laser light is turned off. while the chlorine current quickly drops to its original value, the sulfur current first increases to a value that is substantially larger than the value before the target was illuminated and then returns to its original value on a time scale of a few minutes. the reason for this effect is still unclear. in order to investigate the contribution of photodetachment of sulfur to the effect, the laser source was replaced with a nd : yag laser producing radiation with a wavelength of 1064 nm. the corresponding photon energy of 1.17 ev is too small to neutralize any of the ions of interest. interestingly, both the cl and the s currents showed the same behavior as with the 445 nm laser, as can be seen in fig. 4. these results rule out photodetachment of s as the cause of the reduction of the sulfur beam. the time constant for changes in the source output was close to 20 s. the general trend of the results from gunilla could be reproduced at vera using typical agcl - samples for ams, i.e. with sulfur at ppm levels. the sulfur output from the ion source was monitored via the s count rate in a split anode ionization chamber. since molecules are efficiently destroyed during the stripping process in the tandem accelerator, events in the detector are unambiguously sulfur ions without any molecular background. reproducing the effect on sulfur also strengthens the argument that molecular background played a very minor role in the results obtained at gunilla (see above). the source delivered 512 a of cl current at an ionizer power of 70 w. the response in sulfur had a time constant of several seconds, while the chlorine current took a few minutes to reach equilibrium conditions. the finding that a low ionizer power favors the investigated laser effect was verified. even at constant ionizer power the observed decrease in the sulfur to chlorine ratio ranged from a factor of about 1.3 for all 4 large targets (20 mg agcl) to a factor of almost 6 for 5 out of 6 small targets (2 mg agcl). generally, these changes in sulfur to chlorine ratio were smaller than at gunilla, despite a better focusing of the laser beam that yielded 400 mw of laser light in a 1 mm 1 mm area at the target. the explanation could be the less efficient cooling of the cathode via the multi - cathode target wheel compared to the direct cooling of the cathode rod in the single - cathode source used at gunilla. apart from initial differences described above, the flat target used at gunilla developed a deep sputter crater, whereas no signs of cratering were found on vera 's targets. a study of 10 identical cathodes was conducted to investigate the reliability of this method for routine ams measurements. 6 shows the sulfur to chlorine ratio as well as the chlorine current for a 2 h period of constant sputtering of the same sample, which was illuminated during time periods ranging from 2 to 10 min. although the lasers used throughout the experiments were cw lasers, the word shot will be used for these minute - long illumination periods in the following. the high sulfur output when first sputtering the sample arises from surface conditions and is present in almost all agcl - samples. the sulfur to chlorine ratio then stays constant for almost an hour until the laser is applied. interestingly, the typical sulfur reduction is preceded by a several seconds long cleaning peak in sulfur output, but only for the first laser illumination. afterwards when switching off the laser light, the sulfur to chlorine ratio rises again, although in most cases not to its initial value. such a long - term cleaning effect was only observed for small agcl targets with very low sulfur content. provided that the initial sulfur contamination is sputtered away, the effect of laser light on the isotope currents seems independent of sputter age. pre - sputtering the sample for an hour did not change the response to laser light. another effect is that the time constant of the response of the cl current to the laser light increases with the number of laser shots applied to the cathode from about 20 s in the first shot to about 100 s after 5 shots. the amplitude of the cl response also tends to become smaller, typically by 50% after 5 shots. it should be noted that another seven cathodes, not shown in figure, showed similar behaviors. for better comparison of the laser - induced effect, the sulfur to chlorine ratios plotted here have been normalized to a curve fitted to the s / cl values prior to each laser shot. the same illumination sequence was applied to all three cathodes, except for the first laser shot which was not applied to cathode nr. the magnitude of sulfur to chlorine reduction clearly depends on the number of laser shots already applied or possibly the accumulated illumination time but not on the length of the individual laser shot. the data also shows that the effect is not depending on the sputter age of the cathode before the first illumination. finally, the sulfur to chlorine production ratio induced by laser light has been applied in a regular cl ams measurement at vera. the sample was a reference material with a nominal cl / cl ratio of (1.57 0.02) 10. (measured values are expected to be somewhat lower because of roughly 70% detector efficiency for cl.) initially, the sample was sputtered for 15 min. next, two runs of 7 min each with 30 min of continuous sputtering in between, were performed without laser light. both yielded the same cl / cl ratio of (1.14 0.02) 10, and almost equal s / cl ratios of (23.3 0.05) 10 and (23.9 0.05) 10, respectively. immediately after the second run the laser was turned on, and after a 2 min wait a run of 7 min was performed with laser light. the cl / cl ratio of (1.11 0.02) 10 agrees very well to the previous runs. the interfering isobar s was reduced by a factor of 2.5 to a s / cl ratio of (8.99 0.03) 10. this substantial reduction of sulfur is clearly visible in the energy loss spectra from the ionization chamber shown in fig. hence, the laser introduces no isotope fractionation (also the cl / cl values remained constant) but changes only the elemental composition of the negative ion beam. 2 shows a comparison of two mass spectra recorded with and without laser. an increase in chlorine current by a factor of 2 and a decrease in oxygen and sulfur currents by more than a factor of 5 were observed when approximately 100 mw of laser light was directed onto the cathode. the ion currents did not change immediately after switching the laser on or off. the time constants for the currents to adjust to a change in laser intensity were of the order of several seconds up to minutes. since we could not resolve atomic from molecular ions this is, however, unlikely since the measured isotopic abundances match the natural abundances of sulfur and chlorine isotopes. in particular, there was no observed excess at mass 32, indicating only little if any interference from o2. after sputtering the sample for more than an hour, the mass scans in fig. the ion source output was stable and the observed change in the ion currents of the elements is an effect of laser light and not an effect of sputter time. the measurements were repeated several times on the same sample giving sulfur suppression factors of 1020. thus, the estimated total cl current emitted from the source was of the order of 10 a, i.e. at the same level as at vera (see below). when the operational parameters of the ion source were varied, significant changes in the size of the effect could be observed. while the ionizer power given below may not be best suited to quantify ion source conditions, it is the only parameter directly accessible at the two facilities. generally, sulfur suppression worked best with low ionizer power of 7080 w, producing 510 a cl output. increasing the cl output to 40 a with 100120 w of ionizer power reduced the effect on the sulfur to chlorine ratio to approximately 1.5. even with constant operating parameters of the ion source, i.e. ionizer power, output current, cathode current and cesium oven temperature, the magnitude of the effect differed over time without obvious correlation to the sputter age of the cathode. therefore, we believe that other source parameters, which could not be measured in the current apparatus, played an essential role. this could be, for instance, the cesium vapor pressure, the sample surface temperature or the cesium coverage on the sample. thus, the observations are hard to disentangle and they can not be attributed to a particular parameter. the dependence of the effect on the laser power was also investigated. 3. already as little as 8 mw laser power at the cathode induced a noticeable change in the sulfur output. the data shows a quadratic behavior of the sulfur reduction as a function of the laser power. we also observe a peculiar effect when the laser light is turned off. while the chlorine current quickly drops to its original value, the sulfur current first increases to a value that is substantially larger than the value before the target was illuminated and then returns to its original value on a time scale of a few minutes. the reason for this effect is still unclear. in order to investigate the contribution of photodetachment of sulfur to the effect, the laser source was replaced with a nd : yag laser producing radiation with a wavelength of 1064 nm. the corresponding photon energy of 1.17 ev is too small to neutralize any of the ions of interest. interestingly, both the cl and the s currents showed the same behavior as with the 445 nm laser, as can be seen in fig. 4. these results rule out photodetachment of s as the cause of the reduction of the sulfur beam. the general trend of the results from gunilla could be reproduced at vera using typical agcl - samples for ams, i.e. with sulfur at ppm levels. the sulfur output from the ion source was monitored via the s count rate in a split anode ionization chamber. since molecules are efficiently destroyed during the stripping process in the tandem accelerator, events in the detector are unambiguously sulfur ions without any molecular background. reproducing the effect on sulfur also strengthens the argument that molecular background played a very minor role in the results obtained at gunilla (see above). the source delivered 512 a of cl current at an ionizer power of 70 w. the response in sulfur had a time constant of several seconds, while the chlorine current took a few minutes to reach equilibrium conditions. the observed decrease in the sulfur to chlorine ratio ranged from a factor of about 1.3 for all 4 large targets (20 mg agcl) to a factor of almost 6 for 5 out of 6 small targets (2 mg agcl). generally, these changes in sulfur to chlorine ratio were smaller than at gunilla, despite a better focusing of the laser beam that yielded 400 mw of laser light in a 1 mm 1 mm area at the target. the explanation could be the less efficient cooling of the cathode via the multi - cathode target wheel compared to the direct cooling of the cathode rod in the single - cathode source used at gunilla. apart from initial differences described above, the flat target used at gunilla developed a deep sputter crater, whereas no signs of cratering were found on vera 's targets. a study of 10 identical cathodes was conducted to investigate the reliability of this method for routine ams measurements. 6 shows the sulfur to chlorine ratio as well as the chlorine current for a 2 h period of constant sputtering of the same sample, which was illuminated during time periods ranging from 2 to 10 min. although the lasers used throughout the experiments were cw lasers, the word shot will be used for these minute - long illumination periods in the following. the high sulfur output when first sputtering the sample arises from surface conditions and is present in almost all agcl - samples. the sulfur to chlorine ratio then stays constant for almost an hour until the laser is applied. interestingly, the typical sulfur reduction is preceded by a several seconds long cleaning peak in sulfur output, but only for the first laser illumination. afterwards when switching off the laser light, the sulfur to chlorine ratio rises again, although in most cases not to its initial value. such a long - term cleaning effect was only observed for small agcl targets with very low sulfur content. provided that the initial sulfur contamination is sputtered away, the effect of laser light on the isotope currents seems independent of sputter age. pre - sputtering the sample for an hour did not change the response to laser light. another effect is that the time constant of the response of the cl current to the laser light increases with the number of laser shots applied to the cathode from about 20 s in the first shot to about 100 s after 5 shots. the amplitude of the cl response also tends to become smaller, typically by 50% after 5 shots. it should be noted that another seven cathodes, not shown in figure, showed similar behaviors. for better comparison of the laser - induced effect, the sulfur to chlorine ratios plotted here have been normalized to a curve fitted to the s / cl values prior to each laser shot. the same illumination sequence was applied to all three cathodes, except for the first laser shot which was not applied to cathode nr. the magnitude of sulfur to chlorine reduction clearly depends on the number of laser shots already applied or possibly the accumulated illumination time but not on the length of the individual laser shot. the data also shows that the effect is not depending on the sputter age of the cathode before the first illumination. finally, the sulfur to chlorine production ratio induced by laser light has been applied in a regular cl ams measurement at vera. the sample was a reference material with a nominal cl / cl ratio of (1.57 0.02) 10. (measured values are expected to be somewhat lower because of roughly 70% detector efficiency for cl.) initially, the sample was sputtered for 15 min. next, two runs of 7 min each with 30 min of continuous sputtering in between, were performed without laser light. both yielded the same cl / cl ratio of (1.14 0.02) 10, and almost equal s / cl ratios of (23.3 0.05) 10 and (23.9 0.05) 10, respectively. immediately after the second run the laser was turned on, and after a 2 min wait a run of 7 min was performed with laser light. the cl / cl ratio of (1.11 0.02) 10 agrees very well to the previous runs. the interfering isobar s was reduced by a factor of 2.5 to a s / cl ratio of (8.99 0.03) 10. this substantial reduction of sulfur is clearly visible in the energy loss spectra from the ionization chamber shown in fig. hence, the laser introduces no isotope fractionation (also the cl / cl values remained constant) but changes only the elemental composition of the negative ion beam. at this point the effect induced by laser light has been studied at two facilities where the influence of several parameters has been investigated. the laser light induced a significant change in oxygen, sulfur and chlorine negative ion production from a agcl target. the long time constants and the wavelength independence of the effect are strong evidence that no direct photo - induced process on the respective ions is responsible for the observations. in particular, photodetachment of negative sulfur ions can be ruled out since sulfur suppression also worked with an ir - laser. bulk heating of the cathode by the laser is also unlikely to cause the effect. even though the laser power is comparable to the radiation power from the ionizer and to the power transfer of the 3 kev cs beam, an increase of the target temperature by other means, i.e. reduced cooling or higher ionizer power, does not induce similar changes in the sulfur to chlorine ratio. one possible cause could be a localized heating effect in the laser focus on the target surface much stronger than the bulk heating. however, we have no explanation why this should change the sulfur and chlorine output in opposite ways. recently, vogel. suggested that post - ionization of sputtered neutrals by excited neutral cesium plays an important role in cesium sputter ion sources of the middleton type. while charge transfer cross sections for oxygen (and likely also for sulfur) with excited cesium are one order of magnitude higher than with ground state cesium, the case for chlorine is the opposite. changing the population of cs states by laser light may therefore influence the sulfur to chlorine ratio. nevertheless it remains to be explained, why the two largely different photon energies used yielded similar effects. an explanation could be that neutral cesium (both ground state and excited) is reduced by thermal effects induced by the laser. for chlorine, post - ionization might play a minor role compared to the increased output due to local heating of the sample. thus, exploring the physics requires probing the target surface temperature and diagnosing the cesium conditions, especially the population of various atomic states. we would like to emphasize that the above discussion is merely an attempt to indicate possible explanations. however, we believe that the impact on applications is significant. the most important outcome of this work is that the effect induced by laser light can be successfully applied in regular cl ams measurements (fig. 8). the experiment clearly demonstrates that this method is a viable technique to reduce the interference of s in cl detection without introducing losses in the chlorine beam. while an additional sulfur reduction by a factor of 2.5 may not seem impressive furthermore, implementation of the technique requires no major investments and no major changes to existing ams facilities. | graphical abstracthighlight the effect of cw laser light on the production of s and cl was studied. the s current was reduced by one order of magnitude with 100 mw of laser power. the cl current became enhanced. time structure and power dependence of the effect were investigated. the effect was successfully applied in a regular ams 36cl measurement. |
in japan, it is estimated that there are 43 million (23 million men and 20 million women) hypertensive patients 1. hypertension (ht) has been reported to increase the risk of cardiovascular disease (cvd), including heart disease and stroke 2, 3, 4, 5. the stroke morbidity and mortality rates have been reported to be higher in east asian countries than in western countries 1. of 834,000 deaths from noncommunicable diseases and injuries in japan, high blood pressure (bp) accounted for 104,000 deaths 1. previous studies found that home bp monitoring (hbpm) was readily accepted by and performed by hypertensive patients 6, 7, 8. moreover, bp control was found to be better with these systems than with traditional methods 9, 10, 11. margolis. reported that bp control was better with home bp telemonitoring systems and pharmacist case management than with usual care 12. we believed that these systems could be useful for monitoring side effects of antihypertensive drugs. pharmacist management programs, which was conducted using bp telemonitoring systems, were recently introduced in our community pharmacy (haruka community pharmacy) 13. pharmacist comanagement, and a female patient who was under one of these programs was found to have orthostatic dizziness induced by antihypertensive drugs. here, we present the case of a patient who experienced side effects induced by antihypertensive drugs and show the importance of pharmacist bp management programs using telemonitoring systems for monitoring side effects of antihypertensive drugs in a community pharmacy. a 55yearold woman with ht was advised to measure her bp regularly by her doctor. she consulted with a pharmacist at haruka community pharmacy, and the pharmacist recommended that she participate in a pharmacist bp management program. she agreed to participate in the program and started taking antihypertensive drugs (azilsartan, 20 mg / day ; cilnidipine, 10 mg / day) on the same day. the home bp telemonitoring system involved the use of medical link (omron healthcare, kyoto, japan). this system wirelessly transmits bp data to a central web server via a mobile network. the pharmacist advised that she measure her bp twice per day (at the time of awakening and at bedtime), and provided her with information on the importance of lifestyle modification via a printed handout before starting bp monitoring 13. briefly, the pharmacist collected information regarding her lifestyle from an interview and advised her about lifestyle modification. her systolic and diastolic bp values and drug history are presented in figures 1 and 2, respectively. although she did not measure bp at home before the monitoring period, the frequency of bp measurement was 96.1% after starting the program (fig. the mean systolic and diastolic bp values from day 0 to day 13 were 136 mmhg and 83 mmhg, respectively. therefore, her doctor switched azilsartan (20 mg / day) to olmesartan (20 mg / day) and cilnidipine (10 mg / day) to azelnidipine (16 mg / day) on day 15. moreover, indapamide (1 mg / day) was added on the same day. her body weight (50 kg) did not change from day 0 to day 15. furthermore, to improve muscle tone, etizolam (0.25 mg / day) and afloqualone (70 mg / day) were started on the same day. the mean systolic and diastolic bp values from day 15 to day 21 were 104 and 66 mmhg, respectively. therefore, the pharmacist believed that the antihypertensive drugs might be responsible for her orthostatic dizziness and consulted with her doctor to check whether the drugs should be changed. the mean systolic and diastolic bp values from day 22 to day 29 days were 106 and 66 mmhg, respectively. the pharmacist called her on day 29 to check whether she was still experiencing orthostatic dizziness. the pharmacist again consulted with her doctor to check whether the drugs should be changed based on her symptom and bp values. olmesartan (20 mg / day) and azelnidipine (16 mg / day) were discontinued, and indapamide (1 mg / day) was restarted on day 29. her orthostatic dizziness improved, and the mean systolic and diastolic bp values from day 30 to day 93 were 122 and 72 mmhg, respectively. her systolic bp values were over 140 mmhg on days 62, 79, and 87. therefore, her doctor added amlodipine (2.5 mg / day) on day 93. the mean systolic and diastolic bp values from day 94 to day 101 were 116 and 68 mmhg, respectively. she did not experience orthostatic dizziness induced by antihypertensive drugs from day 94 to day 101. in the present case report, the pharmacist advised the patient with ht to perform hbpm, and she successfully performed monitoring at regular intervals. the pharmacist could consult with her doctor based on her symptom of orthostatic dizziness induced by antihypertensive drugs and her bp values, which resulted in the improvement of her orthostatic dizziness. etizolam and azelnidipine are metabolized by cyp3a4, and the blood levels of these drugs increase via drug drug interactions. etizolam can cause dizziness as a side effect, and dizziness may worsen if drug drug interactions occur. orthostatic dizziness induced by antihypertensive drugs can be improved by reducing the dose of the drugs or switching to other antihypertensive drugs. in the present case, improvement in orthostatic dizziness after modification of the treatment indicated that the patient 's dizziness was induced by antihypertensive drugs. hbpm and medical interview are important to prevent symptoms induced by antihypertensive drugs. in japan, pharmacists in a community pharmacy obtain the home bp values from selfreports or medical reports of patients ; however, selfreports are less reliable than medical reports. medical reports are based on the records of medical staff ; therefore, the updating frequency is lower for medical reports than for selfreports. although home bp telemonitoring can solve these problems, bp telemonitoring systems have been introduced in a small number of pharmacies in japan. to our knowledge, this is the first case report of the use of a bp telemonitoring system to monitor side effects of antihypertensive drugs in a community pharmacy. our findings suggest that an hbpm system can improve pharmaceutical management in a community pharmacy. however, to operate this system effectively, the frequency of measuring home bp should be high. although the frequency of measuring home bp was high in present case, further studies are required to assess the introduction of a bp telemonitoring system for patients with poor adherence. pharmacist bp management programs using telemonitoring systems might be useful for monitoring side effects of antihypertensive drugs in a community pharmacy. | key clinical messagewe previously started pharmacist blood pressure (bp) management programs using telemonitoring systems for monitoring side effects of antihypertensive drugs in a community pharmacy. the present case demonstrates that pharmacist bp management programs using telemonitoring systems are useful for monitoring side effects of antihypertensive drugs in a community pharmacy. |
an inescapable fate of growing old is the gradual slowing of the cognitive and mental capacities. subjective complains start in the fifth or sixth decade of life, indicating the possibility that dementia comes in 2030 years earlier. even before the stage of sci, by 3 decade of life our cognitive function starts declining and healthy aging starts. this article will present and discuss the available cognitive, electrophysiological, radiological and pathological and biochemical evidences of healthy aging also we will try to delineate natural process of aging from pathological aging. these changes may occur in the areas of visual and verbal memory, visuospatial abilities, immediate memory, or the ability to name objects. non - verbal memory impairments are also considered to be a common cognitive deficit associated with aging. biologists believe that our bodies begin to degenerate from the third decade of life and so does our brain. research carried out in the last two decades have suggested the possibility to recognize alzheimer 's disease (ad) or pathological aging many years before the mildest symptoms appear. ad is itself a subtle process ; it does not spread like a forest fire rather it starts slowly, grows daily, and is eventually followed by dementia. the initial stage of ad starts with the stage of subjective cognitive complains (sci), one review found the prevalence of sci among aged 65-year old or more varied from 25% to 56%. several authors have suggested a two - component view of aging, in which one component is associated with normal aging processes, while a second component indicates pathological processes. the first component studies revolve around changes in the volume and function of the following areas of our brain, prefrontal cortex - related frontal - striatal, and prefrontal cortex - related frontal - parietal circuits, and their associated neurotransmitter systems, including dopamine. the neural circuits in this component are associated with high - level cognitive operations referred to as executive control. these processes help us to maintain focus on task - relevant information at the time of distraction, an ability which fades up with aging. patients with frontal lobe lesion show impairment of short term memory, difficulty with selective attention, and executive function such as planning and organization of information. the effects of aging on this component could be because of age - related structural changes and volumetric decline in the pfc. during memory tasks, healthy older people showed a reduced activation in the pfc while the same region was most activated in the younger group.[68 ] however, both groups sometimes may show equivalent activation. older adults often display greater bilateral pfc activation on tasks in which younger adults have unilateral activation. this age - related phenomenon is a sign of compensatory function, implying that older adults recruit homologous regions in the contralateral hemisphere to boost performance with declining neural efficiency. working memory performance has been found to be associated with wisconsin card sorting task (wcst). wcst an effective tool to test working memory has found to be particularly sensitive to dysfunction in dorsolateral prefrontal cortex (dlpfc). another tool raven 's progressive matrices (rpm), test general intelligence by using abstract reasoning tasks. both of these tests displayed a significant negative correlation with aging. this study also showed decreased activation of dlpfc starting at 20 years of age during working memory test by wcst tools. in contrast to the changes observed during normal aging, pathological changes are centered in the medial temporal lobes that are primarily associated with ad. volume loss begins in the entorhinal cortex (ec), an important relay between the hippocampus and associated cortex. the progression from normal aging to frank ad can occur in a graded fashion, lasting perhaps a decade or longer. with aging comes general cognitive slowing, attention or working memory decline and loss of new learning activities. reaction time gets slower as we become older. a study done among academic professors of 31 - 70 years old age group showed slowing of reaction time by 3.9 ms per year. fluid types of cognition abilities which include problem solving, spatial manipulation, and mental speed, peek in the mid 20s, and then decline gradually until 60s, when more rapid decline takes place. recently research has shown that some aspects of age - related cognitive decline begin in healthy educated adults when they are in their 20s and 30s. three tests on reasoning, speed of thought and spatial visualization were conducted to find out the earliest age at which performance starts declining. these tests showed that peak scores were at 27 years of age and then they started declining. the cognitive aging depends on various causes and cognitive outcome depends on education level and health. education, good health, absence of the apoe 4 allele, and physical activity may be protective and prevent cognitive decline. cognitive processing speeds and memory retrieval speeds decline by as much as 20% by age of 40 years and 40 - 60% by age 80 years. crystallized cognitive abilities, however, increase well into the later decades of life and only decline at advanced ages. it is important to introduce techniques that would give us more insight into natural brain aging and could possibly differentiate it from pathological neurodegeneration. interestingly some studies showed that in the same age group, higher -wave frequency activity is related to higher cognitive ability in normal healthy as well as demented population. high - frequency -wave reflects the oscillation of specific neural systems for the elaboration of sensorimotor or semantic information whereas low frequency -wave is primarily related to subject 's global attentive readiness.a gradual decrease of -wave and a global slowing of the background eeg are noted with aging. from early childhood up to puberty -frequency increases but then starts to decline with age. a young adult, 20-year - old will have an a - wave with the highest frequency, a frequency of 10.89 hz and then -wave frequency declines gradually in a liner manner ; at 70-years of age -wave shows a drop of 2.65 hz down to a frequency of 8.24 hz. a study in a large number of different age grouped participants showed that older age group had delta waves in the occipital area and -1 and -2 waves in the parietal, occipital, and temporal regions. limbic areas have less magnitude of -1 and -2 waves in older age group compared to younger participants. compared to healthy normal elderly subjects, ad patients have high amplitude of delta and theta wave frequencies and low amplitude of - and -wave frequencies. a decrease of - and -wave frequency was found in ad patients compared to the same age mild cognitive impairment (mci) subjects. - and -activities are more common anteriorly in ad patient 's brain compared to both the controls and mci subjects. no significant difference in -wave - and -wave amplitude when combined were the best variables to differentiate between ad patients and controls ; it is also an important tool by which we can differentiate between ad and mci subjects. polysomnography (psg) is a comprehensive recording of the biophysiological and electrophysiological changes that occur during sleep. a study done by lauer of individual from 18 to 65 years of age showed significant polysomnographic changes with aging ; decrease of sleep time period, decrease of total sleep time, decrease of sleep efficiency index. sleep onset latency and intermittent time awake were found to increase with aging, similarly, duration of stage 1 sleep increase with aging while the slow wave activity of sleep decreased with aging. throughout aging stage 2 sleep remained unchanged. with aging sleep becomes more fragmented and lighter ; stage 1 sleep increases and percentage of slow wave sleep (sws) decreases. in patient with ad it could be look like changes are exaggeration of normal aging but that is not true. in patients with ad we see more wakefulness and it is because of increased in duration of stage 1 sleep, we can even see decrement changes in sws in ad patient which is not a feature for same aged control. in mild to moderate stage of ad stage 2 sleeps loses its own texture, k complex and sleep spindles no more make this stage distinguishable from other stage of the sleep. subsequently stage 1 and stage 2 sleep patterns starts look like same and new stage of sleep emerges and is known as indeterminate nrem sleep. rem latency was found to decrease while first rem period significantly increased with advancing age but continuous decrement in the percentage of rem sleep with the progression of disease process is also typical feature of ad which is not seen in normal healthy aging as total rem sleep percentage remains stable. magneto encephalography is a potential investigation of choice which can help us understand the cortical rhythm in pathological aging. it was seen that the frequency of delta and theta waves increases in the ad group compared to healthy control and slow wave activity differs significantly between temporoparietal regions of both hemispheres. temporoparietal and sources are enhanced in amplitude in ad compared to old subjects in association with hippocampal atrophy. aging originates from a diverse group of mechanism that makes a gray zone between normal aging and pathological aging process. normal aging is associated with some degree of neuron loss and volume loss with increasing adjacent glial cells. recent studies have shown that loss of brain volume is due to loss of neuronal cell size rather than loss of cell volume, and the cognitive decline associated with normal aging is because of dysfunction rather than loss of neurons or synapses. decrease in the amount of synaptic proteins involved in structural plasticity of axons and dendrites have suggested that disturbed mechanism of plasticity may contribute to cognitive dysfunction during aging. noninvasive technique like volumetric mri has shown a progressive decline in cerebral hemisphere by 2 - 3% a decade and increase in ventricular volumes by 2% a decade.[2932 ] there was also a whole brain volume (wbv) decline by 0.22 a year between the ages of 20 - 80 years with hastened decline with advancing age. healthy volunteers, an age - related decline in the volume of the prefrontal cortex, insula, anterior cingulategyrus, superior temporal gyrus, inferior parietal lobule, and precuneus was found. these decreases might contribute to the cognitive changes during normal aging. in patients with ad, a significant reduction of gray matter volume in the hippocampalformation and ec bilaterally was noted. some regions, such as the pfc, show particularly dramatic changes in volume, while other regions, such as the occipital cortex, are relatively unaffected by normal aging.[33436 ] the largest age - related volumetric changes in older adulthood appear to occur in the pfc, approximately average volume loss of approximately 5% per decade starts from 3 decade of life. the biggest age - related volume loss occurs in the lateral pfc, with an estimated rate of loss of 0.91% per year. orbito - frontal pfc declination were nearly as large as lateral pfc, with an estimated annual loss of 0.85%. but in case of alzheimer 's disease greatest degeneration is seen in the inferior pfc. striatal volume declines at about 3% per decade, while caudate volume declines at approximately 0.75% per year. medial temporal lobe consists of the hippocampus and adjacent, anatomically related cortex, including entorhinal, perirhinal, and parahippocampal cortices. these structures, presumably by virtue of their widespread and reciprocal connections with neocortex, are essential for establishing long - term memory for facts and events. adult lifespan studies (with participants in their 20s to 80s) with intervals of 5 years have estimated the rate of decline in hippocampal volume at 0.79 - 0.86% per year. the declination in ec volume however, was smaller- with the estimated rate of change being approximately 0.33%, although this accelerates somewhat in later life. longitudinal measurements of hippocampal atrophy increase many - fold from a range of 0.2 - 3.8% per year in normal elderly to a range of 4.9 - 8.2% per year in ad. decline in ec volume in mci patients is twice, compared to age - matched controls. in general, these results suggest that normal aging has modest structural effects on the hippocampus and adjacent medial temporal lobe structures. pathological processes related to mci and ad, however, have severe effects within the ec even early in disease progress, which reduces the potential for effective hippocampal involvement in memory function. brain areas which are involved with cognitive processes affected in ad showed robust relationship with white matter degeneration and gray matter (gm) degeneration. therefore, cortical function and white matter (wm) degeneration are related in aging and dementia. a study done by yulin measured both absolute and fractional % gm and % wm volumes in healthy adults aged of 2086 years and evaluated the data by age and sex this study showed that the rate of change in % gm and % wm with aging does not depend on sex, although female subjectshave slightly higher % wms, compared to male subjects this study also found a 4.9% difference in % gm between the younger groupand the older groups. the decline of volume of % gm occurs by a relatively young age (age 20 years), and the decline occurs constantly in a linear fashion.while the % wm, in contrast, shows a quadratic pattern of change, volume increases until an age of around 40 years. but once wm degeneration starts at age of 40, the loss is more consistent and faster than gm. modern noninvasive imaging techniques are an excellent means to examine age - related changes from pathological changes. the functional state of brain can be best detected by pet scan ; flurrine-18-fluorodeoxyglucose has been used before to reveal alteration of regional metabolic rate of normal aging and other psychiatric disorders. various regional metabolic activities varied among subjects within same age group as well as over decades. the anterior posterior gradient changes over the time and with advancing age, because of significant decrease in frontal lobe activity in later years. less frontal lobe activity becomes more notable after age of 30 years, but more dramatic decline of frontal brain metabolic activity occurs after age of 60, and this is the time when temporal lobe metabolic activity also starts to decline. cerebellum to cerebral cortex metabolic activity ratio tends to increase with age, and it is consistent with decrease metabolic activity of cerebral cortex, which becomes more prominent after age of 40 years. at the same time cerebellum 's metabolic activity remains constant up to age of 40 years. findings from other research showed that metabolic activity of frontal, temporal and parietal brain decreases with aging but this decline is more rapid in case of frontal lobes. one study was done to detect cerebral metabolites like n - acetyl aspartate (naa), and choline (cho) and creatine (cr) in vivo by newer proton magnetic resonance spectroscopy. naa is a specific neuron marker, as it is found at high concentration almost only in neurons. the major findings of this study were : a) hippocampal naa / cho and naa / cr decreases with advancing age, whereas cho / cr remains relatively stable. b) hippocampal volume decreases with age, c) hippocampal naa ratios and volume change occurs at similar relative rates with advancing age. this is consistent with the view that hippocampal volume loss is due to neuronal loss. metabolites ratio and volume of hippocampus decrease starts consistently from age of 36 years, and it occurs in a linear fashion with aging. pathological hallmark of ad is amyloid peptide (a), the sticky plaque which was first discovered around the meningeal blood vessels of individuals with down 's syndrome who developed ad nearly 20 years earlier. later, the same a peptide was recognized as the primary component of the senile (neuritic) plaques of brain tissue of people with ad. these discoveries initiated the beginning of the modern era of research on this common, devastating neurodegenerative disease. deposition of amyloid and tau protein is limited to specific brain regions. with the recent advancement in neuroradiology it is now possible to look into the pathological changes that occur in ad much before the onset of clinical symptoms. pib - pet scan displayed that amyloid plaque deposition occurs with high frequency (about 30%) in non - demented elderly. the frequency of individual with high mean cortical binding potentialfor pib was 0% at age 45 - 49 years, 5.7% at 50 - 59 years, 195% at 60 - 69 years, 25.8% at age 70 - 79 years, and 30.3% at age 80 - 89 years, and csf a42 was 18.2% at age 45 - 49 years higher than 14% at age 50 - 59 years. it demonstrates that ongoing degenerative process of central nervous system is detectable as early as, in the 5 decade of life. csf markers are now well - validated : reduced csf - a and raised csf - tau have a strong relationship with early stage of ad. another study has shown that changes in csf biomarkers already reach a plateau in a preclinical phase, before cognitive decline begins, that is, even before mci can be diagnosed. initial changes are seen in the basal cortex, most frequently in the poorly myelinated temporal areas such as perirhinal and enterorhinal fields (stage a), in stage b, ad changes occur in the neocortical area and in the hippocampal formation. finally deposits are found all over cortex (stage c). early amyloid deposition occurs in poorly myelinated areas of the basal neocortex. after that ad pathology spreads to cortical region (that is temporal, parietal and frontal), leading to early signs of pathological changes. neurofirillary tangles (nfts), neutrophil threads (nts), and neuritic plaques (nps) are different types of intraneuronal change can be seen in ad. in general nps changes some young individuals develop first neurodegenerative changes in brain, in their 3 decade of life. one case showed stage a amyloid changes among 61 individuals of 26 - 30 years age group ; however, 11 cases among 61 individuals of the same age group showed stage i / ii intraneuronal changes. in normal aging, a few nft can be observed in layer ii of the ec and nft are occasionally encountered in the stratum pyramidale of the ca1 field. the inferior temporal cortex (itc) and superior frontal cortex (sfc) remain devoid of nft. in contrast, very mild ad is characterized by higher nft densities in the ec and ca1, and nft are consistently observed in layer iii of the itc. the neocortical areas show no neuronal loss, but a significant degree of neuronal loss is present in layer ii of the ec and in the ca1 field. in severe ad, nft are found in high densities in layer ii of the ec, in the ca1 field, and in layers iii, v, and vi of the itc, with moderately high density in sfc as well. the degree of neuronal loss parallels nft densities in these regions, although nft numbers alone can not account for the total loss of neurons, indicating that not all dying neurons necessarily undergo nft formation. one of the most significant features of ad is substantial neural loss in hippocampus and cerebral cortex, the regions which are involved in memory and cognition. studies have shown that high hippocampal diffusivity values in the hippocampal formation of healthy elderly individuals beyond their 50s, predicts memory decline. myelin breakdown is predicted to be an important aspect of ad.[6062 ] according to this hypothesis, late myelinating fibers are the earliest ones to get involved in ad. corpus calosum which connects two cerebral hemispheres is the largest white matter bundle in the human brain and this is where early degeneration begins. one study has shown that reduction in genu size occur even in the preclinical stage of dementia which reinforced the theory of late myelinating fibers get affected in ad first. our body is mostly dependent on aerobic metabolism which takes place in mitochondria ; the powerhouse of a cell. this may disrupt the energy supply for myelinataion, which may explain the metabolic theory of ad. a study measured effects of age on ph in brain tissue. it showed a significant age associated decrease in brain ph (0.53% per decade). this acidification not only induces apoptosis but also substantially alters enzyme activities and promotes the development of ad. a study by smith on postmortem brain showed that carbonyl content rises exponentially with aging, double in rate in the frontal pole compared to occipital pole. it also showed decreases in glutamine synthetase and creatine kinase activities in the frontal compared to occipital pole. this study also proved that oxidation vulnerable enzymes activity decrease with aging and protein oxidation products accumulate in the brain. glutamine synthetase enzyme plays an important role in the regulation of cellular acid - base balance. decrease in intracellular ph can change position of intracellular iron, which can eventually result in production of oxygen free radicals and further protein oxidation. only glutathione synthetase activity in the frontal cortex is significantly decreased in ad which was another differentiating factor between healthy aging and ad. in addition to the volumetric and functional age - related changes in the pfc, various neurotransmitter systems in the pfc and striatum also undergo age - associated changes. of these, three are very important, dopaminergic system, cholinergic system and glutaminergic system. the dopamine system which plays an important role in attention or executive control of memory also loses its efficiency with aging. studies showed that there is age - related decrease in dopaminergic receptors in the caudate nucleus and the substantianigra.the rate of neuronal loss in the substantianigra which is mostly dopaminergic, found to be about 6% per year. this loss of dopaminergic neuron is responsible for cognitive decline and many neurological symptoms that increase in frequency with age, such as - decreased arms swing and increased rigidity. postsynaptically, the density of d-2 dopamine receptors also decline by 2550% in human striatum. on the contrary, the decline of the number of d2 receptors begin at age of 40 years and it occurs at the rate of approximately 8% per decade. lower level of d2 receptors is also associated with a low glucose metabolism in the pfc. by age 60, normal older adults display 58% decline compared to younger adults in striatal uptake of a dopaminergc analog (in subjects with parkinsonism, decline is about 85%). also, dopamine transporter availability has been estimated to decline at a rate of 4.9% per decade in the caudate nucleus and 4.2% per decade in the putamen. one research was done to investigate dopaminergic activities in post - mortem brains of patients with various types of dementia and brain of healthy elderly people. it showed in the caudal putamen level dementia with lew body (dlb) patients showed significantly low (57% of normal level) dopamine uptake compared to control, but patients with parkinson 's disease had the lowest level (75% of normal level), and it was unchanged in alzheimer 's disease. this study also showed d3 receptor binding capacity in the patients with ad was 20% higher than control at caudal striatum. same kind of result came out with another study where in vivo dopamine (d2/d3) receptor availability was examined by [(11)c ] raclopride (rac) pet scan in patients with mild and moderate ad with delusion. it showed increased striatal dopamine (d2/d3) receptor availability in delusional ad compared to same aged control group. nucleus basalis of meynert (nbm) is a group of distinct neurons which is rich in acetylcholine and choline acetyltransferase. it is a major source of cholinergic innervation of the cerebral cortex. in various types of dementia, patients with low acetyl choline show general decrement of mental capacity and learning and cognition. a study on postmortem brains of patients with ad and senile dementia showed profound diminishment of cholinergic neurons in the cortex. this study also showed neurons of the nucleus basalis of meynert underwent a profound (greater than 75%) selective degeneration in ad patients. is reduced to 35 - 50% of normal level.[7477 ] furthermore, synaptic reuptake of choline, which is essential for the synthesis of ach molecules, is reduced to ~60% of normal levels in ad. but in the hippocampus, 4 subunit receptor numbers remains constant, though 72 subunit significantly decreases with age. these findings suggest that nicotinic receptors decrease during aging with differing vulnerability between subunits and brain regions, which may contribute to the reduced cognitive function with aging. in ad both types of cholinergic receptors, nicotinic receptors and muscarinic receptors binding property decrease to their 60 - 70% and 80 - 100%, respectively. other important receptor for memory perspective would be n - methyl - d - aspartate (nmda) receptors, which are seen in high density throughout the cerebral cortex and hippocampus and play an important role in learning and memory. calcium flux through nmdars is thought to play a critical role in synaptic plasticity, a cellular mechanism for learning and memory. the capacity for thinking and remembering is derived from various input and output pathways between the hippocampus and the neocortex, pyramidal cells which accounts for more than 70% of all connection use glutamate for this process. in healthy individuals, the glutamatergic neurotransmission cycle begins in the mitochondria of hippocampal neurons, where the enzyme glutaminase catalyzes the conversion of glutamine to glutamate. nmda antagonist drug has shown benefits in case dementia, as it slows the progression. it has been hypothesized that constant activation of nmda receptors leads to neuronal over activity which contributes to an unfavorable signal - to - noise ratio during glutamatergic neurotransmission and, hence, to the absence of long - term potentiation. in patients with ad, available evidence points to a disruption in the glutamatergic neurotransmission cycle at the point of glial cell reuptake of free glutamate from the synapse. neuropathological studies have documented reduced levels of glutamate reuptake in the frontal and temporal cortices of patients with ad, possibly due to oxidative modification of the glutamate transporter molecule which is not common in healthy aging. furthermore, diminished uptake by vesicular glutamate transporter (which mediates the packaging of these glutamate molecules into vesicles) has been reported in patients with ad. the difference between healthy brain aging and changes of ad remains a gray zone. in this article we tried to discuss about the differences between pathological and physiological neurodegenerative process from radiological, pathological, biochemical, electrophysiological perspective. we can see distinctive pathological changes, radiological changes and electrophysiological changes in ad compare to healthy degenerative aging of brain. healthy aging of brain starts from 3 decade of life which begins 30 years before the sci or first pathological changes of brain. though ad has been studied very well recently, still its exact etiopathogenesis is unknown. not much study has been done to discover or differentiate if the pathological aging in ad is the continuation of healthy aging process, but hopefully with new early diagnostic tools we will be able to delineate preclinical ad from healthy aging in the near future. | the world population is becoming older now. the boom of the elderly population comes from public health efforts to improve living conditions and prevent disease, and from improved medical interventions. people more than 65-year - old who are representing 12.9% of the population now is expected to grow to be 19% of the population by 2030. very few numbers of diseases will have such socioeconomic burden on society in the newer world. although alzheimer 's disease (ad) has been studied very well recently, still its exact etiopathogenesis is unknown. currently there are no available tests for the definitive diagnosis of ad. so the clinical diagnosis of ad remains a diagnosis of exclusion. this limits the potential for early intervention. the difference between normal degenerative processes of brain and preclinical changes of ad is a gray zone and there is no particular way to distinguish between the two. now several modalities like functional magnetic resonance imaging (fmri), positron emission tomography (pet) scan, electrophysiological tests and cerebrospinal fluid (csf) biomarkers for tauopathy and a have shown to be promising in the development of early diagnostic tools for neurodegenerative changes and help us to differentiate between healthy aging and pathological aging. in this article we tried to discuss about the differences between pathological and physiological aging process from radiological, pathological, biochemical, and electrophysiological point of view. however, differentiating between physiological and pathological dementia still remains a challenge. |
however, it often results in collateral damage to the surrounding of the primary tumor site. the most frequent complication after radiotherapy treatment for prostate cancer is radiation proctitis with incidence rates ranging from 2% to 39%. acute radiation proctitis occurs immediately or up to 3 months after the initiation of radiotherapy. the presenting symptoms are diarrhea, tenesmus, urgency, mucus discharge, and bloody stools. in contrast, chronic proctitis may appear years after the completion of therapy usually manifesting by gross hemorrhage. the newer irradiation modalities3d conformal radiotherapy and intensity - modulated radiotherapy are usually not associated with severe side effects such as ulceration, fistulation, necrosis, and stricture, but bleeding due to radiation proctitis still occurs even at a lower rate. radiation proctitis is diagnosed by endoscopy where edematous, friable, and with abnormal telangiectatic vessels mucosa is usually demonstrated [1, 2 ]. the pathophysiology of radiation proctitis is only partially elucidated, and several mechanisms have been put forward. the earliest studies suggested that blood vessels are the main site of injury and that microvascular compromise is an important factor in the natural history of radiation proctitis. the pathogenetic process triggered by radiation seems to be multifactorial including several molecular events leading to inflammation, hypoxia, neovascularization, and fibrosis [35 ]. various cytokines and growth factors have been implicated in the pathogenesis including hypoxia - inducible factor 1 (hif-1), transforming growth factor 1 (tgf-1), fibroblast growth factor 1 (fgf-1), and vascular endothelial growth factor (vegf) [68 ]. radiation - induced inflammatory response is closely related to oxidant stress, while an increase in free oxygen radical production has been documented as a result of infiltrating inflammatory cells and of radiation - induced ischemia [9, 10 ]. angiogenesis plays an important role in many chronic inflammatory diseases, while vegf is the main stimulatory factor. it is secreted by macrophages, endothelial cells, fibroblasts, smooth muscle cells, and activated platelets. vgef induces proliferation, inhibits apoptosis of endothelial cells, increases vascular permeability, and has a chemotactic effect on macrophages. vegf gene expression is regulated by various mechanisms the most important being hypoxia, especially through upregulation of hif [12, 13 ]. there is very limited and conflicting experimental data regarding the role of angiogenesis in the context of postradiation proctitis, especially in the chronic form of the disease. the information derives mainly from mice studies where a gradual increase of vegf after an early peak of hif was observed in rectal tissues during the first 3 months after their irradiation. as for humans, an increased angiogenesis not corresponding to a vegf overexpression has been demonstrated in cases of radiation proctitis at 738 months after irradiation. the aim of our study was the immunohistochemical investigation of angiogenesis in postradiation rectal mucosa in association with vegf expression and in relation to histological findings in the early and late postradiation period in order to provide some evidence regarding the involvement of neoangiogenesis in mucosal injury. we prospectively enrolled consecutive patients with prostate cancer who were newly referred and treated with 3d conformal radiotherapy schedule of 7274 gy of total dose. in all patients, the total dose did not exceed 70 gy for more than 25% of rectal volume. four rectal biopsies were obtained randomly at sigmoidoscopy from normal - appearing mucosa at least 1 cm away from any macroscopically - visible lesion using a 6 mm forceps. the endoscopy was performed before, at the completion of (within an interval of 13 days), and 6 months after radiotherapy. none of the individuals had a personal history of colorectal cancer, and all had the same bowel preparation. the study was approved by the hospital 's ethics committee, and an informed consent was signed by every individual before the procedures. four m thick paraffin sections were stained with hematoxylin and eosin for histological assessment and for immunohistochemical analysis. the following primary antibodies were applied : (i) monoclonal mouse anti - human cd31 antibody (mo823 ; dako, glostrup, denmark) at a dilution 1 : 50 and (ii) monoclonal mouse anti - human vegf antibody (m7273 ; dako, glostrup, denmark) at a dilution 1 : 50. detection was carried out using the dakoenvision detection system peroxidase / dab+ (k4065 ; dako, glostrup, denmark). histological evaluation included inflammatory infiltrates, presence or absence of cryptitis and of crypt abscesses, erosions or ulceration, and thickening of the subepithelial collagen plate. for the evaluation of immunostaining, 10 high - power fields were examined arbitrarily under 400 magnification for each case. (vegf - vi) and microvascular density (mvd), that is, the mean number of vegf positive cells per vessel or the mean number of vessels per field, were calculated, respectively. for each case, agreement was reached by simultaneous evaluation of the specimens using a two - headed microscope. statistical analysis was performed using the statistical package statgraphics centurion xv (statpoint technologies, inc. the box includes 50% of the results falling between the 25th and 75th percentile (interquartile distance). outliers, that is, points more than 1.5 times the interquartile range from the end of the box, are shown as open squares. three additional patients missed to followup and were excluded from the analysis. during the followup period, 2 patients reported rectal bleeding that settled without specific intervention, while in 4 patients endoscopy revealed the presence of mild to moderate radiation proctitis not needing a therapeutic intervention according to endoscopic classification by zinicola.. histological findings in the early postirradiation period were predominantly characterized by inflammatory changes. in 6 cases, inflammatory changes were consisted with mild active colitis characterized by infiltration of the lamina propria mainly by neutrophils, mild cryptitis, and few crypt abscesses. small telangiectasias were found only in one case, while fibrin microthrombi were not observed. table 1 summarized the histological findings in an individual patient at the completion of radiotherapy. in the late postirradiation period, the predominant diagnosis was mild nonspecific chronic colitis which was ascribed to 8 cases. table 1 summarized the histological findings in an individual patient 6 months after completion of radiotherapy. histological findings such as crypt distortion, fibrosis, and vascular telangiectasia were limited probably due to the fact that our study was restricted to the early postirradiation period (first 6 months). moreover, radiation tissue damage is expected to be less severe in relation to the contemporary radiation modalities. microvasculature was demonstrated by cd31 immunostaining, while vegf was detected in endothelial cells and in few stroma cells showing cytoplasmic staining (figure 2). both vegf - vi and mvd were increased at the completion of radiotherapy, the difference being significant only for vegf - vi ; 0.41 0.24 versus 0.17 0.15, p = 0.001 and 7.6 2.2 versus 7.3 3.2, p = 0.61, respectively. at the time of completion of radiotherapy, the mean values of vegf and cd31 were significantly higher in cases with active colitis in histology examination compared to those showing no activity (0.55 0.12 versus 0.24 0.23, p = 0.012 and 8.95 1.9 versus 6.08 1.43, p = 0.02, resp.). the increases of both indexes were also observed six months after the end of radiotherapy ; the difference was significant for vegf - vi and mvd compared to those before irradiation (0.29 0.19 versus 0.17 0.15, p = 0.02 and 10.5 3.1 versus 7.3 3.2, p < 0.005, resp.). vegf - vi six months after the end of radiotherapy was significantly lower compared to index at the time of radiotherapy completion (0.29 0.19 versus 0.41 0.24, p < 0.05). the results are summarized in figure 3, while table 2 presented the sequential change of vegf and cd31 in an individual patient. at the completion of the radiotherapy, there was a trend, which did not reach significance, for correlation between vegf and cd31 (p = 0.087). the same, without statistical significance, trend was also observed after 6 months of radiotherapy completion (p = 0.099). radiotherapy has been established as the treatment of choice for patients with prostate cancer. the use of conformal radiotherapy succeeded in reducing irradiation to organs at risk such as rectum, enabling a higher dose to the target volume [15, 16 ]. even with this advanced technique, symptoms suggestive of postradiation rectum damage occur in up to 20% of patients depending on the dose and treatment method [1719 ]. acute symptoms observed early after external beam therapy of prostate cancer are thought to be mainly inflammatory in nature and settled spontaneously over few months after exposure in the majority of patients. however, in selected individuals postradiation reactions could be sustained for unclear reasons for months and even years after radiotherapy. this chronic form of radiation proctitis seems to be the result of submucosal inflammation, fibrosis, and angiogenesis. angiogenesis is a complex process mediated by multiple cells types and mediators, and besides its well - known role in cancer, it plays a critical role in hypoxic conditions and in several chronic inflammatory diseases. moreover, it potentiates the inflammatory response by increasing the influx of inflammatory cells as well as a chemotactic mediator [22, 23 ]. in our study, it was preceded by mucosal inflammation and concomitant vegf expression appearing as early changes shortly after irradiation, while neither acute nor chronic ischemic lesions were found. these consecutive findings provide indications of a pathogenetic link between inflammation and vascularization, taking into consideration the higher values of vegf and cd31 expression in patients with active colitis at the end of radiotherapy. the occurrence and/or persistence of newly formed microvessels after remission both of the inflammatory process and of the decrease of vegf expression suggest a later postradiation and postinflammatory manifestation. since now there are only few treatment options for patients with symptoms, such as bleeding due to radiation proctitis. endoscopic treatment with argon plasma coagulation (apc) is considered the preferred treatment modality for radiation proctitis. although apc successfully ameliorates symptoms associated with mild endoscopic radiation proctitis, it is less effective in severe cases of the disorder. in these cases, nevertheless an absolute toxic agent is a useful therapeutic strategy [14, 24, 25 ]. according to our results, angiogenesis constitutes a component of mucosal injury in radiation proctitis ; the clinical significance of new vessels formation following vgef expression relies on the putative higher risk of bleeding complications. thus, we could speculate on a possible effectiveness of antiangiogenetic drugs regarding the inhibition of excessive vascularization and the reduction of bleeding complications. however, the use of these compounds is restricted to cancer treatment and has been only experimentally investigated in colitis models and in ibd patients. our findings in the early postradiation period have demonstrated an association of increased vegf expression with radiation - induced inflammation probably related to oxidative stress. this observation favors a beneficial impact of anti - inflammatory and antioxidant medication early in the course of postirradiation proctitis by preventing the initiation of inflammatory process directly after irradiation. although someone could argue that there is no need to treat asymptomatic proctitis, it is well known to clinicians that asymptomatic radiation - induced proctitis is potentially a symptomatic one with or without rectal bleeding with an increasing time - related possibility. thus, radiation - proctitis should be treated in a prevention manner, and our results showing early involvement of vgef in the pathogenesis of this disease imply that the blockage of this factor could be a promising therapeutic option. under this view, a combination of vitamin e (400 iu tid) and vitamin c (500 mg tid) has been proved a successful and sustained treatment of chronic radiation proctitis. a limitation of our study is the fact that due to the relatively small study populations, we were not able to make any correlation among clinical symptoms, endoscopic findings, and microscopic features. as only a minority of our patients had symptoms (2 had bleeding that settled without specific intervention) or endoscopic finding of radiation proctitis (4 patients), further studies are needed in order to examine a putative relation between histological findings and clinical symptoms. moreover, the period that we choose to evaluate our patients could raise concerns, as late radiation - induced rectal injury might occur months or years after radiotherapy. we evaluated our patients with endoscopy 6 months after radiotherapy completion because our objective was to identify factors of prognostic significance regarding the course of the disease. early proctoscopy, even in asymptomatic but endoscopically confirmed rectal damage, has a significant role in predicting late radiation - induced proctitis [28, 29 ]. in conclusion, our study showed that in postradiation rectal biopsy specimens neoangiogenesis seems to be inflammation - related and constitutes a significant postradiation component of the tissue injury. the involvement of inflammation meditator vegf in the pathogenesis of radiation proctitis suggests that the blockage of the expression of this factor may represent a promising therapeutic option in patients with refractory to available therapies cases of the disorder. | background. inflammation mediators related to radiation proctitis are partially elucidated, and neovascularization is thought to play a key role. objectives. to investigate the expression of vascular endothelial growth factor (vegf) and cd31 as angiogenetic markers in postradiation rectal tissue. methods. rectal mucosa biopsies from 11 patients who underwent irradiation for prostate cancer were examined immunohistochemically for the expression of vegf and cd31 at three time settings before, at the completion of, and 6 months after radiotherapy. vegf expressing vascular endothelial cells and cd31 expressing microvessels were counted separately in 10 high - power fields (hpfs). vegf vascular index (vegf - vi) and microvascular density (mvd) were calculated as the mean number of vegf positive cells per vessel or the mean number of vessels per hpf, respectively. histological features were also evaluated. results. vegf - vi was significantly higher at the completion of radiotherapy (0.17 0.15 versus 0.41 0.24, p = 0.001) declining 6 months after. mvd increased significantly only 6 months after radiotherapy (7.3 3.2 versus 10.5 3.1, p < 0.005). the histopathological examination revealed inflammatory changes at the completion of radiotherapy regressing in the majority of cases 6 months after. conclusions. our results showed that in postradiation rectal biopsy specimens neoangiogenesis seems to be inflammation - related and constitutes a significant postradiation component of the tissue injury. |
cardiovascular disease (cvd) is known to be the leading cause of mortality worldwide resulting in 17.1 million deaths, with 13 million deaths attributed to coronary heart disease and stroke alone ; of these, more than 80% of deaths has occurred in low- to middle - income countries. it is projected that by the year 2030, cvd - related mortality will rise up to 25 million, mainly from heart disease and stroke. similarly, global statistics on diabetes are also alarming, as the disease is rapidly increasing worldwide and future projections of its burden are reported to rise particularly in pakistan and other developing countries [2, 3 ]. it is evident that diabetes is an independent risk factor for cvd, and people with diabetes are three to four times more likely to develop cvd [4, 5 ]. the development of cvd in diabetic patients is a cause of concern, as it is a major reason for hospitalization, premature morbidity, disability, and mortality [6, 7 ] which lead to an increased cost of care. it is reported that over 70% of the cost attributed to diabetes care is associated with its cardiovascular complications. lifestyle behaviors such as lack of exercise, psychosocial factors, and exposure to smoking further increase the risk of developing cvd [812 ] and are also highly prevalent in less developed countries [13, 14 ]. on the other hand, prevention and modification of these unhealthy behaviors can lead to reduction in cvd and resultant mortality [13, 15 ]. literature reveals that at least 80% of cvd (coronary heart disease and cerebrovascular diseases) could potentially be avoided by adopting healthy lifestyle [1, 15 ]. the clustering of such unhealthy lifestyle practices has very important implications for both public health practitioners as well as for clinicians. it is well known that the risk of developing cvd multiplies many folds when related lifestyle risk factors coexist as compared to their individual risk. numerous studies have identified the clustering pattern of cvd - related factors among various groups of population [16, 17 ]. a study from japan reported the clustering of cardiovascular risk factors, but the study mainly focused on biological risk factors such as glucose intolerance, dyslipidemia, and hyperuricemia. recently, khuwaja and kadir reported the clustering of lifestyle risk factors in pakistan, but the study participants did not include a high - risk population for cvd such as patients having diabetes. we therefore conducted this study among diabetic patients to assess the prevalence and clustering pattern of cvd - related lifestyle risk factors and their associations with cvd. this multicentre cross - sectional study was conducted in four outpatient clinics in karachi, the largest city and economic hub of pakistan with a population of over 16 million, which represent all ethnicities and socioeconomically diverse populations in the country. an attempt to capture a wide spectrum of clinical and socioeconomic factors was made by enrolling study participants from four different clinics including family medicine, internal medicine, specific diabetes care, and endocrinology clinics representing both public and private sectors. all patients having type 2 diabetes visiting their respective clinics for follow - up visits were consecutively recruited till the final sample size was achieved. we considered patients having type 2 diabetes who were labeled as type 2 diabetic patients by their treating physician and recorded in their medical files. however, patients suffering from type 1 diabetes or women with gestational diabetes were excluded. in this study, we were not expecting any adverse event to study participants ; even so, prior to enroll in the study, consent was obtained from all the study participants. participants were assured about the confidentiality and anonymity of their information, and all efforts were made to ensure privacy. after reviewing the study protocol and questionnaire, permission was granted from all the concerned clinics to conduct this study in their clinics. face - to - face interviews were conducted to get the required information, and each interview took about 20 minutes. pretested structured questionnaire was used to obtain information about sociodemographic (gender, age, and education level) and lifestyle risk factors (level of physical activity, psychosocial history, smoking status, and exposure to passive smoking). the questionnaire used to assess the presence of anxiety and depression was hospital anxiety and depression scale (hads). this tool is validated in national language of pakistan (urdu) and was used extensively to study anxiety and depression among various outpatient as well as inpatient settings. one of its main features is that the items, which could relegate to problems such as insomnia, unemployment, eating disorders, headache, and fatigue, have been excluded, in order to avoid false positive cases among persons with somatic diseases. the hads - d (depression) covers mostly anhedonia and loss of interest, which form the core of depression symptoms, whereas hads - a (anxiety) covers mainly the fields of tension and worry. the hads questionnaire consists of 14 items (sentences - questions) with answers in four grades on a likert scale. a score up to 8 indicates that the individual is free of symptoms, and a score beyond 8 defined that the symptomatology of anxiety or depression is present. the variables which included blood pressure, glycemic levels, lipid profile, height, and weight were noted / verified from patients ' medical records. body mass index (bmi) was calculated as weight in kilograms divided by height in meter squares. study participants were classified as obese if their bmi > 25 kg / m. hypercholesterolaemia was defined according to atp iii criteria (200 mg / dl). individuals were classified as hypertensive if they were previously diagnosed and currently on antihypertensive medication. however, participants in whom elevated levels of blood pressure were discovered for first time at the day of interview (indexed visit) were not included in hypertensive category, as it is recommended to have at least two elevated blood pressure readings at two different times. cardiovascular disease (coronary artery disease and/or stroke) was considered to exist if there was a history of coronary heart disease (angina, myocardial infarction) verified through medical records of a prior episode and confirmed by work - up including electrocardiography, echocardiography, and exercise treadmill test, while having stroke was solely labeled on the basis of patient 's history along with file note verification of treating physician. cvd - related lifestyle factors such as physical inactivity were defined as not doing moderate to vigorous activity for 30 minutes or more, at least 4 days in a week, and participants falling in this group were categorized as physically inactive. passive smoker for this study was defined as any person who has been exposed to second - hand smoke for at least 30 minutes in a day, for at least 5 days of the week either at home and or at work place, for last six months, and more. to analyze the defined objectives of this study, the initial required sample size was 895 study participants. however, we approached 1000 consecutively eligible type 2 diabetic patients from the four clinics to participate in the study. in total, 87 patients refused to participate in the study, while the required information was incomplete and missing for 26 patients. all the data was collected, cleaned, and validated by medical graduates specifically trained for this task. the data was analyzed using the statistical package for social sciences (spss) version 19. mean and standard deviations (sd) for continuous variables and percentages for categorical variables and lifestyle factors were calculated separately. clustering of lifestyle factors was studied as none, one, and two or three. in model i, multivariable analysis using multiple logistic regressions was carried out to evaluate the association of combined effect of lifestyle factors with cvd among patients with type 2 diabetes, while in model ii, the association of clustering pattern of lifestyle factors with cvd was assessed. age, sex, educational status, and body mass index are well known confounders for lifestyle factors and cvd [7, 13 ] ; we therefore adjusted these variables in both models to evaluate the independent association of cvd with lifestyle risk factors and their clustering pattern. cross - tabulation and chi - square test of significance was applied to identify the association of lifestyle factors and clustering pattern by gender, age, and educational status. all smokers in this study were men ; hence, we did not include it in the final model. baseline characteristics of the study participants are presented in table 1. in all, 43.6% of the study participants were up to the age of 50 years, and there was a preponderance of females (57.4%). about half of the patients reported family history (siblings, parents, and grandparents) of diabetes. in all, 41% of the diabetic patients were also concurrently diagnosed to have hypertension ; however, overall mean systolic and diastolic blood pressure levels of study participants were substantially high. there were also higher mean values of lipid profile (total cholesterol, low - density lipoproteins, and triglycerides) and body mass index. of the study participants were taking oral hypoglycemic agents, while one - third of the patients were also taking low - dose aspirin on regular basis. in table 2, proportion distribution and clustering pattern of lifestyle factors and their associations with cvd are described. amongst all, 30.3% (95% ci = 27.233.2) of the diabetic patients had cvd. over 65% of participants were physically inactive, 71.4% had anxiety and/or depression, and 40.1% were exposed to passive smoking. in the univariate analysis, all the three studied lifestyle factors and their clustering pattern were found to be significantly associated with cvd (physical inactivity : crude or = 1.7, 95% ci = 1.22.3 ; psychosocial factors : crude or = 2.2, 95% ci = 1.63.2 ; passive smoking exposure : crude or = 1.7, 95% ci = 1.32.3 ; clustering of any two or three lifestyle factors : crude or = 6.1, 95% ci = 2.713.7). however, the confounders (age, sex, educational status, and body mass index) reported in the literature were not fulfilling the criteria of being a confounding factor in this study except age which was confounded by the exposures of physical inactivity and clustering of lifestyle factors. in model i of the final multivariable analysis (table 2), the odds of having cvd were higher among those who were physically inactive (adjusted or = 1.6 ; 95% ci = 1.22.3) and had anxiety and/or depression (adjusted or = 1.9 ; 95% ci = 1.42.8), and among those exposed to passive smoking (adjusted or = 1.7 ; 95% ci = 1.22.3) while adjusted for age, sex, educational status, and body mass index. in another model, the odds of having cvd increased with the clustering of lifestyle factors : for having any one factor (adjusted or = 2.7 ; 95% ci = 1.26.2) and for clustering of two or three factors (adjusted or = 6.1 ; 95% ci = 2.713.7) after adjusting for the similar factors described in the first model. the association of sociodemographic characteristics with cvd - related lifestyle factors and their clustering pattern are presented in table 3. in comparison to males, similarly those with no / less education were more inactive compared to their counterparts having education of more than five years (77.7% versus 53.6% ; p < 0.001). significant majority of study participants having anxiety and/or depression were females (74.5%), elderly (77.0%), and having no / less education (75.6%) compared to their counterparts. clustering of two or three cvd - related lifestyle factors was significantly higher among females compared to males (69.9% versus 55.3% ; p < 0.001) and elderly compared to younger patients (68.1% versus 58.0% ; p = 0.004). clustering of these factors was also higher among study participants having no / less education compared to those with more education (71.8% versus 56.2% ; p < 0.001). it is well known that modifiable lifestyle factors such as physical inactivity, psychosocial stress, and smoking result in an increased risk of cvd, while control of the same substantially decreases the development of cvd [1, 15 ]. the results of our study are consistent with those of previous studies and highlight the importance of adequate control of these lifestyle factors, particularly among high - risk people like diabetics, to prevent the development and progression of cvd and its consequences. in a recently conducted study on healthy canadian adults, only 10% of the study population was found to be physically inactive, as opposed to 60% healthy adults in pakistan. the presence of such high levels of physical inactivity is particularly harmful among people with diabetes, as the presence of diabetes itself confers increased cardiovascular risk, and the coexistence of physical inactivity further amplifies this risk. the high prevalence of physical inactivity in an earlier study from pakistan and in our study may be attributed to the lack of awareness regarding the role and benefits of exercise in preventing cvd as highlighted from the earlier studies in pakistan. furthermore, watching television and playing computer games have considerably risen in this part of the world, along with unavailability of safe playgrounds and walking tracks rendering majority of the population physically inactive. furthermore, the burden of psychosocial factors which predispose to anxiety and depression is also reported to be more prevalent in developing countries. by using hads scale, our study showed that more than 70% of the study participants were suffering from anxiety and/or depression. however, results of a study conducted in the united kingdom using the same scale revealed substantially lesser proportion of these disorders among diabetic patients. this sharp difference in prevalence of mood disorders may be attributed to the high levels of poverty, poor socioeconomic conditions, and scarce health care facilities and resources in developing countries. it is evident that smoking is a strong risk factor for developing cvd in general and among diabetics in particular. it is also reported that passive smoking also increases the risk of chronic diseases including cvd [8, 10 ]. a community - based survey recently reported that about half of the study participants in pakistan were exposed to passive smoking. using the same definition of passive smoking in our study, over one - third of the diabetic population this high proportion of exposure reflects the lack of awareness about the hazards of passive smoking among the general population. in pakistan, in spite of laws and constitutions to restrict smoking at public places, people freely smoke in public transport, shopping malls, restaurants, and even many of the work places and offices. it is documented that, in pakistan, up to 34% adults smoke cigarettes. however, in our study, 13% of the study participants were reported as being current smokers and all of them were males. this lower prevalence can be attributed to the fact that in this study, interviews were conducted in the presence of patients ' family members / attendants, raising the possibility that majority of the participants did not admit that they smoked, as it is viewed as a socially unacceptable habit in this part of the world. another possible explanation for the lower prevalence of smoking may be due to the fact that patients might have given up smoking after developing diabetes and its complication. furthermore, previous work reported was done only in men, and it is well reported that when compared to women, smoking among men is more prevalent in both developed as well as in developing countries [13, 26 ]. recently, data collected from a multisite five asian countries survey revealed that a substantial proportion of study population had clustering of lifestyle risk factors, and similar findings were also reported in a community - based study from urban pakistan. in our study, a very small proportion of the participants were found to have none of cvd - related lifestyle factors, while one - fourth had one of these risks, and majority had clustering of two or three factors. this pattern of unhealthy lifestyle clustering reflects the possibility of poor awareness and harmful attitude and practices regarding healthy behaviors. results of this study also endorse the existing literature that physical inactivity, adverse psychosocial factors, and exposure to smoking are strongly associated with cvd [1, 15 ], and clustering of these factors enhances the risk further [13, 28 ]. with the increase in prevalence of cvd - related modifiable lifestyle factors among high - risk population like diabetics in developing countries, identification of specific target groups within such population is important in order to introduce comprehensive and integrated preventive strategies aimed to reduce cvd. though literature from the western world has identified females to have a lower risk of developing cvd, evidence from south asia reveals that both men and women bear an equal risk of developing these diseases. furthermore, a study from pakistan reports women to have a greater risk of developing cvd than men. the results of our study reveal that all the cvd - related lifestyle factors and their clustering are significantly higher among women. hence, the female population in our study was found to be at higher risk of developing cvd owing to increased prevalence of unhealthy lifestyle behaviors. the presence of increased cvd - related risk factors in women can be attributed to the fact that up to 50% males have been reported to smoke at home, thus exposing the females to passive smoking as well. furthermore, the social status of women in our patriarchal culture leads to increased prevalence of psychosocial risk factors among them. moreover, cultural restrictions limit females to going outside their homes without an accompanying male family member resulting in decreased likelihood for joining sport physical and exercise centers and gymnasiums. it is well known that increasing age is associated with increased cardiovascular risk due to acceleration of atherosclerosis and other cardiovascular risk factors. this study showed that up to 80% of the older population was found to have anxiety and/or depression. this increased psychosocial suffering may be attributed to the presence of more chronic illnesses and cvd as well as challenging life situations such as being more isolated and dependent. clustering of two or more lifestyle risk factors was also found to be present in up to 70% of the elderly patients, providing further explanation for increased cardiovascular risk in this age group. these results are in accordance with results of various studies conducted elsewhere [16, 27 ]. it has been reported that higher level of education has a protective role with regard to healthy lifestyle and behaviors [33, 34 ] as it leads to greater awareness and improved conscience regarding health. the results of our study also suggest low prevalence of cvd - related factors such as physical inactivity and anxiety and/or depression among people having more years of education. similarly, clustering of these risk factors was in lesser proportion among the educated participants, reinforcing the fact that people with less education have an increased risk of unhealthy lifestyle practices. the overall metabolic control (blood pressure levels, glycemic control, lipid levels, and body mass index) of our study participants was poor. it is well reported that the management and control of diabetes is a real challenge for health care providers as well as people having diabetes [7, 22 ]. many possible reasons and explanations exist for poor control of disease, like lack of knowledge about the disease among diabetic patients, poor quality of care provided by treating physicians, and excessive cost for the management of diabetes [6, 36 ] which many patients can not afford in resource - constrained countries. since this study employs a cross - sectional study design, temporal relation between cvd and its lifestyle factors could not be identified. coronary artery disease is often silent with regards to symptoms in diabetic subjects, and therefore noninvasive studies (such as myocardial scintigraphy and dobutamine stress echocardiography) should have been performed for a thorough evaluation of the cardiac status. however, due to cost and resource limits, we have not evaluated the cardiac status using these tests. similarly, hba1c, another comparatively costly test, is recommended to evaluate the overall glycemic control, but it was only reported in 285 patients. therefore, we can not comment about the overall glycemic control of study participants during the period of time. all the smokers in this study were male ; hence, this important factor was not included in the final analysis. we did not inquire about the dietary habits of study participants which is an imperative lifestyle factor for cvd. all the study centers were from one metropolitan city ; therefore, it may not be possible to generalize the findings to the rural population that might have different behaviors. furthermore, being a cross - sectional study, we can not assess the impact of successful medical treatment on the occurrence of cvd. age, sex, educational status, and body mass index are well known confounders for lifestyle factors with cvd [7, 13, 37 ] ; however, in this study except for the age, other established confounders were not found to be associated with cvd, lifestyle risk factors, and their clustering pattern. this multicenter study highlights very high prevalence and clustering of cvd - related lifestyle factors, particularly physical inactivity, anxiety, depression, and exposure to passive smoking. the presence of such a high burden of these factors among diabetic patients is a cause of concern and requires urgent interventions in order to prevent and control cvd. these interventions should be based on a comprehensive and integrated approach covering all of these lifestyle factors rather than any single factor to anticipate their cumulative effects. we recommend that health care providers should provide awareness and education regarding cvd risk factors and their prevention to patients and their families / caregivers. furthermore, safe walking tracks, playgrounds, and relaxation avenues should also be made available to allow more people to engage in physical activities and relaxation programs. further research is suggested to explore this very important avenue in more detail and to design and test interventions accordingly. | background. we evaluated the prevalence and clustering pattern of cardiovascular disease (cvd) related lifestyle factors and their association with cvd among patients with type 2 diabetes. we also examined the association of these factors with various socio - demographic characteristics. methods. a total of 1000 patients with type 2 diabetes were interviewed in a cross - sectional, multi - center study in out - patient clinics in karachi, pakistan. results. in this study 30.3% study participants had cvd. majority of the patients were physically inactive and had adverse psychosocial factors. forty percent of the study participants were exposed to passive smoking while 12.7% were current smokers. only 8.8% of study subjects had none of the studied lifestyle factor, 27.5% had one, while 63.7% had two or three factors. cvds were independently associated with physical inactivity, adverse psychosocial factors, passive smoking and clustering of two or three lifestyle factors. physical inactivity was more prevalent among females and patients with no / less education. proportion of adverse psychosocial factors were higher among females, elders and patients with no / less education. clustering of these lifestyle factors was significantly higher among females, elderly and no / less educated patients. conclusion. these results suggest the need of comprehensive and integrated interventions to reduce the prevalence of lifestyle factors. |
end stage renal disease (esrd), the stage 5 of chronic kidney disease, normally requires dialysis or transplantation for survival. the burden of esrd in children is lesser as compared with adults ; however, if esrd occurs in children, consequences can be catastrophic. it should be pointed out that children on dialysis have 30 to 150 times higher mortality rates compared with the general children population. children with esrd end up dying from variety of causes such as cardiovascular diseases, life threatening infections, and malignancy. since esrd patients are on long term dialysis, infections such as hepatitis b (hbv) and hepatitis c (hcv) are commonly reported. although vaccination has significantly reduced mortality rates, dialysis can shorten the duration of immunity against hbv by lowering the protective antibody levels in children who were vaccinated as infants [3, 4 ]. this was consistent with a study in which all patients who were anti - hcv positive had been on dialysis for a mean of 105 months. furthermore, a study also reported a steady rise of the hcv antibody titres in children during the period of dialysis treatment. this may be due to the number of blood transfusions at the time of haemodialysis which has been shown to be a significant risk of hcv infection. many studies have been conducted to determine the rate of hbv and hcv infections among the paediatric esrd population. for instance a study conducted in saudi arabia showed that the prevalence of anti - hcv in children with esrd was 45% compared with the prevalence of 1% among the controls. similarly, another study showed that the prevalence (11.2%) of anti - hcv was much higher in children with chronic renal disease. a study conducted back in 1985 on patients aged between 2 and 18 years with not much data is available on this subject from our part of the world due to nonexistence of a centralized registry. while the incidence of esrd in the united states is declining (a 5.8% decrease in 2012), it continues to be rising in pakistan, with an estimated annual incidence of > 100 new cases per million population [9, 10 ]. epidemiological data on hbv and hcv infection is therefore important for strategies to tackle the spread of the disease. moreover, it is imperative to reliably determine the burden of hbv and hcv disease, to determine the etiology of spread especially in children with esrd, to identify any areas with higher endemicity than the rest of the country and to understand the risk factors associated with its transmission. the primary objective of our study was to determine the frequency rate of hbsag and anti - hcv among children with esrd while the secondary objective was to determine the etiology, gender, and age groups that are predominantly infected. this was a retrospective study carried out at a government hospital during a 12-month period from january 2013 to december 2013. all subjects ' information was kept confidential and a written informed consent was obtained from each participant. all ethical responsibilities were met in accordance with helmshki law. since our government hospital is located in the center of the city where people come from all over the city, a good representative sample of the entire city was collected and analyzed. the sample population included all those children under the age of 18 years who were documented cases of esrd. esrd was defined as individuals with a glomerular filtration rate (gfr) of < 15 ml / min/1.73 m or with signs and symptoms of kidney failure. hbsag and anti - hcv were tested by in vitro immunochromatographic one step assay designed for qualitative determination. the data was collected using a predesigned pro forma to note the aetiology, gender, age, and hbsag and anti - hcv test result of each subject. data was collected by three investigators who were also coauthors of the study. after explaining the purpose of the study, each participant was asked to fill the consent form. two independent authors queried the data from the database to ensure no error was made. age was classified into 3 categories, namely, 19 years, 1014 years, and 1518 years. frequencies and percentages were calculated for presenting categorical variables such as demographic profile and clinical status of patients. age based stratified analysis was also performed to observe pattern of clinical profile among esrd children. 20% (n = 91) of the children were less than 10 years of age while 39% (n = 174) were in the age group 1518 (table 1). the reason for esrd was known for 33.8% (n = 150) patients only (figure 1). the most common known aetiology of esrd was kidney stones (n = 44, 29.3%), followed by small shrunken kidneys (n = 28, 19%) (table 2). hbv was positive in 11 children (2.5%) while hcv was positive in 13 (2.9%) (table 2). the proportion of hbv positivity was found to be 1.1% (n = 1) among children less than 10 years. this proportion was higher in children with the age groups 1014 and 1518 years with 2.8% (n = 5) and 2.9% (n = 5), respectively. on the other hand, hcv was positive in 2.2% (n = 2), 1.7% (n = 3), and 4.6% (n = 8) of the children aged 19 years, 1014 years, and 1518 years, respectively (table 3). table 3 shows age based stratified analysis for secondary outcome variables such as aetiology. children under the age of 10 years had the highest percentage of kidney stone being the reason for their kidney failure (n = 10, 11%) followed closely by the 1518 years age group (n = 18, 10.3%). the prevalence of hbv and hcv in our sample population is 2.5% and 2.9%, respectively. a major hurdle in recording the prevalence of hbv and hcv in the pakistani population is the lack of reporting to a national database. a study showed that the prevalence of hcv among the general population is 4.5%, while another study estimated that 17 million people in pakistan are affected compared with the global reported prevalence of less than 3%, 1.8% in europe, and 2.3% in usa. prevalence of hbv has been shown to be 2.5% in the general population. a few studies carried out in the paediatric population by khan, parker., and hyder. showed that the rates of hcv are 4.09%, 1.3%, and 0.58%, respectively, while a newer study determined the prevalence to be 3.3% in the age group 919 years, while a review showed the incidence of hbv as 1.93.6%. keeping the route of infection in mind, some reasons for the higher prevalence of these infections in our country can be deduced. majority of our population obtains their haircut and facial shaves from unhygienic barber shops, where the practice of using fresh blades for each individual is dubious at best. while this dangerous act used to be much more common, awareness regarding the hazards there still remains a lot of work to be done, as these practices have not been completely abolished and many people do not recognize the significance of needle - stick injuries, proper disposal of used sharp objects, sharing of toothbrushes, and unsafe blood donations, apart from the pervasive presence of intravenous drug abuse. it is possible that many of the children are infected either directly through these injuries or accidents or through vertical transmission from their mothers. hepatitis infections in esrd patients, especially children, represent a special subset of the population. the inflicted individuals have to undergo maintenance peritoneal dialysis, haemodialysis, or renal transplantation. all these are associated with risks of blood - borne infections being transmitted, among other complications. being on dialysis means repetitive exposure to potentially infected instruments and hence increased risk of infections. studies from different regions show varying trends of hbv and hcv infection in these patients. a senegalese study showed 5.6% prevalence of hcv in esrd patients, while in libya it was shown to be 31.1%, in germany 6.1%, in saudi arabia 50%, and in turkey 20.2%. on the other hand, the observed prevalence of hbv infection in esrd patients was 2.6% in libya, 4.1% in europe, 2.2% in japan, and 2.4% in usa. while these studies mostly state the frequencies among the adult populations suffering from esrd, some researchers have worked on the paediatric esrd patients too. from these, the prevalence in saudi population is 45% for hcv and 15% for hbv, in italian population 15% for hcv, and in the egyptian paediatric esrd population 5.9% for hbv and 94.1% for hcv. all these report a much higher incidence of the investigated diseases as compared to our study. as the risk of being infected by blood - borne viruses increases with exposure, patients who are on dialysis for longer periods are at higher risk than those being started on dialysis recently. this would lead to the expectation that children with esrd would be less likely to be infected as compared to adults with the same affliction since they have been enduring dialysis longer. we further found that the aetiology of esrd in our population was unknown in 66.2%. among the known causes, the most common in our sample was urolithiasis. diabetes and hypertension being common culprits in the latter. as far as the aetiology in children while congenital anomalies and hereditary nephropathies are reported from developed nations, infections and other acquired causes make up the majority in developing countries [25, 26 ]. the paediatric aetiology in our population remains mostly unknown, with a high incidence of urinary tract stones which is in contrast to that reported in western countries. a study conducted in karachi shows nephrolithiasis as the major factor in 16%, glomerulonephritis in 26%, and unknown in 50% compared with hereditary / congenital disorders (35.9%) and glomerular disease (21.5%) in usa. this is consistent with our findings which show stone formation as the leading known cause of esrd in children. pakistan, among other countries of the afro - asian belt, has one of the highest incidences of urolithiasis in the world. this entity is observed both in adults and in children and is often neglected which leads to patients presenting with late disease ; a challenge to treat. paediatric urolithiasis in western countries occurs mainly on the backdrop of metabolic abnormalities, anatomical anomalies, and infections while the preponderant etiological basis in developing nations is not clearly defined. it has been shown that there is a genetic component involved in increasing the risk of stone formation, and dietary and environmental components also contribute to the metabolic abnormalities leading to this phenomenon. the importance of urolithiasis as a cause of esrd is based on the fact that it is quite easily preventable and manageable, hence reducing the burden of patients developing renal failure. extrapolating on these evidences, one can make some intelligent guesses regarding the role of environment and diet on our results. in a subtropical region with the sun shining almost the whole year, high temperatures, and humidity, it is no surprise that people living in pakistan, especially the southern coastal areas, arid balochistan, and lower punjab, tend to be dehydrated. increased consumption of salt is common in our society and, with a significant portion of the population not able to afford meat, consumption of vegetables with the resultant load of oxalate provides additional risk factors. an increase in dietary calcium, associated with dairy consumption, reduces the formation of oxalate stones, which could be a possible contributory factor in those with poor feeding habits. these points can help formulating advice to high - risk patients and the population in general regarding the potential prevention of stone formation, leading to decreased morbidity and mortality associated with this pathology. prompt attention to the symptoms produced by urolithiasis is essential to achieve a reduction in incidence ; clinicians should be careful not to dismiss symptoms of abdominal pain, haematuria, or dysuria. another hurdle is neglect and delay in obtaining proper medical advice by the patients and their families ; some of this is due to silent stones, but a more important cause is the practice among people, especially from rural background, to consult hakims / quacks for their ailments. our study has an advantage over some studies cited above in having a much larger sample size. since this study was carried out at a dedicated center for kidney disease, the volume of patients is quite high. not many centers operate in our country providing state - of - the - art care completely free of cost ; this means that the catchment area is quite widespread in terms of geography and socioeconomic strata. it is evident from the literature review that not many studies are available regarding the epidemiology of specific diseases in special populations. our study focuses on a subset within a subset, namely, children ailing with esrd. while this sort of targeted researches may not be of interest to the casual investigator or practitioner, they are important for those intimately associated with these specialties as they provide important epidemiological data as well as guide important decisions on how to reduce the adverse events patients suffered from during their care. the foremost are the facts that this was a retrospective study done in the year 2013 ; hence, any cases before or after that year were not accounted for. although the center is located at the city center and would account for most of the cases reported, it still remains our limitation. hence, the majority of the children would represent people from a low socioeconomic background. this unfortunate affliction represents an additional comorbidity for our patients who are already fighting a life - threatening condition. there is a need for carrying out further work to confirm these findings and expand our recommendations, particularly the sensitive issue regarding proper blood screening. ngos and governmental institutions can play a pivotal role in bringing out the true picture as defined in earlier studies and awareness projects. further data regarding these infections should be collected on a national level, and appropriate measures should be taken by both the government and private setups to reduce the spread of hbv and hcv as they will have a big effect on the quality of life of patients as well as playing a role in reducing mortality. hence, focused efforts should be done to prevent the spread of hbv and hcv and thereby reduce the burden of related chronic liver disease in the country and region, as a whole, especially in a region dominated with child population. | background. end stage renal disease (esrd) normally requires dialysis or transplantation for survival. since esrd patients are on long term dialysis, infections such as hepatitis b (hbv) and hepatitis c (hcv) are commonly reported. methods. this was a retrospective study carried out at a government hospital during a 12-month period from january 2013 to december 2013. the data was collected using a predesigned pro forma to note the etiology, gender, age, and hbsag and anti - hcv test result of each patient. results. 444 children suffering from esrd were included in our analysis. the mean age of sample was 12.7 4.1 years. sixty percent (n = 262) of the children were boys. the most common etiology of esrd was kidney stones (n = 44, 29.3%). hbv was positive in 11 children (2.5%) while hcv was positive in 13 (2.9%). conclusion. this study asserts the need for carrying out further work to confirm these findings and expand our recommendations. it is imperative to reliably determine the burden of hbv and hcv disease and to determine the aetiology of their spread especially in children with esrd. |
adipose tissue dysfunction relies on many and heterogeneous factors, including impaired secretory function, insulin resistance, and lipolysis, which are believed to be caused by the activation of inflammatory mechanisms. in turn, inflammation is activated as a consequence of excessive lipid uptake, adipocyte hypertrophy, and hypoxia. besides the limited ability of oxygen to diffuse between hypertrophic adipocytes, hypoxia also results from microvascular dysfunction and decreased compensatory angiogenesis [14 ]. these mechanisms are thought to contribute to the development and progression of type 2 diabetes. recently, our group demonstrated that microvascular dysfunction and concomitant hypoxia may be caused by methylglyoxal - induced glycation, what may constitute a new factor for adipose tissue dysfunction during type 2 diabetes progression. thus, new strategies improving microvascular function of adipose tissue may strongly contribute to prevent these mechanisms. methylglyoxal (mg) is a highly reactive dicarbonyl compound, endogenously formed during lipid peroxidation and glycolysis. irreversible formation of advanced glycation end - products (age) from methylglyoxal is one of the pathways responsible for diabetes - associated complications, not only due to increased aminoacid crosslinks and protein misfolding, but also due to the rage activation (age receptor) [2, 3 ]. we showed that increased methylglyoxal - induced ages accumulation in adipose tissue of wistar rats leads to hypoadiponectinemia, increased plasma free fatty acids, fibrosis, decreased irrigation, hypoxia, higher levels of apoptotic markers (ratio bcl-2/bax and caspase 3), and macrophage recruitment. as well, other authors showed that mg - induced age accumulation leads to microvascular dysfunction in other models [58 ]. pyridoxamine is a vitamin b6 derivative, which belongs to the b vitamins family, a group of vitamins known as coenzymes of several metabolic cellular pathways. pyridoxamine is known to be an inhibitor of the maillard reaction and a blocker of age formation from amadori products, mainly because it acts as a dual scavenger of free radical and carbonyl species. pyridoxamine was observed to decrease age accumulation, in part due to increased glyoxalase - i expression and decreased oxidative stress and rage levels in several models of diabetic complications [6, 912 ]. this work was designed to assess the usefulness of age inhibition in the adipose microvasculature, after methylglyoxal - induced glycation. unless otherwise stated all reagents were purchased to merck darmstadt (germany), sigma - aldrich (eua) or pancreac qumica sa (spain). antibodies used were directed to actin (mab1501r, millipore, usa), cel (kh025, transgenic inc., japan), rage (ab3611, abcam, uk), tgf- (mab240, r&d systems inc.), bax, bcl-2 (sc 6236 and sc7382, santa cruz biotechnology, usa), and vwf (a0082, dako, usa). in this work we studied 6-month - old wistar rats, from our breeding colonies at the faculty of medicine, university of coimbra. a group of wistar rats was treated with methylglyoxal in the daily water (sigma, usa) during 8 weeks (75 mg / kg / day, diluted in the water). after this period, these rats were divided in two subgroups : one was treated with pyridoxamine (pyr) (sigma, usa) during the following 4 weeks (100 mg / kg / day diluted in the daily water) [13, 14 ], whereas the other did not have any kind of treatment (mg). the control group (c) did not have any treatment during the whole period of the experiment (n = 6 per group). mg administration was suspended at the moment of pyridoxamine treatment initiation, in order to avoid ex vivo interactions with pyridoxamine. animals were kept (2 per cage) under standard ventilation, temperature (2224c), humidity (5060%), and light (12 hours light/12 hours darkness) with free access to water and food (standard diet ao4, panlab, barcelona). in treated animals, the experimental protocol was approved by the local institutional animal care and use committee, and all the procedures were performed by licensed users (felasa). at the end of the treatment, glycemia, fasting (16 hours) and 2 hours after intraperitoneal glucose administration (1.8 g / kg), was measured in the tail vein through the glucose oxidase method, using a glucometer and reactive test stripes (elite - bayer sa, portugal). blood samples were obtained through cardiac puncture from anesthetized animals (ketamine chloride (75 mg / kg, i.m., parke - davis, ann arbor, usa) and chlorpromazine chloride (2.65 serum and plasma were collected using tubes bd vacutainer and bd vacutainer k3e, with 5.4 mg edta (uk), respectively. blood was centrifuged at 3500 g, 4c, 10 minutes and plasma and serum were aliquoted and stored at 80c. after blood collection, animals were sacrificed and epididymal adipose tissue was harvested, washed in 0.9% nacl, and immediately stored in 10% formalin or frozen at 80c. serum levels of cholesterol (total and hdl) and triglycerides were determined using commercial kits (olympus - diagnstica, portugal, produtos de diagnstico sa, portugal). serum concentration of adiponectin was determined by commercially available elisa kits (adiponectin immunoassay kit krp0041, invitrogen). plasma levels of free fatty acids were assessed spectrophotometrically using the half - micro test (11383175001 roche diagnostic, germany). tissue sections of 300 mg were homogenized in a buffer containing 25 mm tris, 150 mm nacl, 1% triton x-100, 1 mm edta, 1 mm egta, 10 mm pmsf, and 40 l / g tissue of proteases inhibitor cocktail (sigma, usa), ph = 7.7 and centrifuged at 14000 g, 20 minutes, 4c. supernatants were collected, centrifuged again, and protein concentration was determined using the bca method (pierce, usa). samples (50 g) were separated by sds - page in 10% acrylamide gels and transferred to pvdf membranes. membranes were blocked with tbst solution (25 mm tris - hcl, 150 mm nacl, 0.1% tween, ph = 7.6) supplemented with 5% bsa. membranes were then incubated overnight at 4c with the respective primary antibodies (cel, rage, tgf-, bcl-2 and bax, diluted 1 : 1000 in tbst solution supplemented with 1% bsa) and during 2 hours at room temperature with the secondary antibodies (anti - rabbit / mouse 1 : 10000 ; ge healthcare, uk). membranes were incubated with ecf and revealed using the typhoon system (ge healthcare life sciences, uk). membrane analysis was performed using the software image quant (molecular dynamics, usa). tissue sections (4 m) were stained with periodic acid schiff (pas ; carbohydrates and glycoconjugates) and masson trichrome (collagen / connective tissue), two slices per animal, three animals per group. immune staining was performed after paraffin removal, hydration, and blocking, following the recommendation of the manufacturer (dab150 immunoperoxidase secondary detection system jh1743622, millipore, usa). sections were incubated overnight at 4c with the primary antibody (tgf- and vwf, diluted 1 : 100 in pbs) and during 1 hour at room temperature with the secondary antibodies (alexa fluor 488 goat anti - rabbit igg and alexa fluor 568 goat anti - mouse igg, invitrogen, usa). finally, sections were mounted with mounting medium (dako, usa) and analyzed in a fluorescent microscope (leica dmire2, leica microsystems, germany). quantification ten images were captured randomly (images containing large vessels were excluded) from two slices per animal / three animals per group. mg administration during 8 weeks (mg group), as well as the treatment with pyridoxamine during 4 weeks (pyr group), did not result in significant alterations of body weight, glycemia, hba1c, triglycerides, and total cholesterol, compared to the control (c) group (table 1). however, mg group showed a significant decrease of hdl cholesterol levels, compared to the c group (p < 0.05), which was reverted by pyridoxamine treatment (pyr group) (p < 0.05) (table 1). regarding serum adiponectin levels,, mg administration led to increased circulating free fatty acids levels, when compared to c group (p < 0.05), suggesting adipocyte dysfunction. in turn, the treatment with pyridoxamine normalized plasma free fatty acids levels (p < 0.01) (figure 1(b)). mg treatment during 8 weeks resulted in increased n - epsilon-(carboxyethyl)lysine (cel) accumulation in adipose tissue, compared to the c group (p < 0.01) (figure 2(a)), but did not cause significant alterations of rage expression (figure 2(b)). pyridoxamine administration significantly reverted cel accumulation in adipose tissue (p < 0.01), leading to values similar to control rats (figure 2(a)). pas staining represents the accumulation of carbohydrates and nonspecific glycated materials. in accordance with cel levels, a substantial increase of pas material was observed in the adipose tissue of mg - treated rats, when compared to the c group. this accumulation was reverted by pyridoxamine treatment, leading to a phenotype similar to control rats (figure 3(a)). the administration of mg during 8 weeks resulted in more fibrotic components in the adipose tissue. once again, the treatment with pyridoxamine resulted in decreased fibrotic material, resulting in a phenotype similar to control rats (figure 3(b)). as well, the transforming growth factor- (tgf-) precursor was observed to be decreased after pyridoxamine treatment, when compared to the mg group (p < 0.05) (figure 4(a)). no significant differences were observed in the cleaved form of the tgf- (figure 4(b)). the histological staining of tgf- showed accumulation in the capillaries, as suggested by its colocalization with the von willebrand factor (figure 4(c)). the ratio between bcl-2 and bax can be used as an indicator of the predisposition for cellular death by apoptosis. the decrease of this ratio in the mg group, when compared to the c group (p < 0.01), indicates that mg - induced glycation leads to a cellular death predisposition. these effects were completely reverted by the treatment with pyridoxamine (p < 0.01) (figure 5(a)). quantification of vwf fluorescent staining was used as a marker of adipose tissue microvasculature, as it is a marker of endothelial cells and is present in the circulation. mg administration resulted in a significant decrease of adipose tissue vwf levels, when compared to control rats (p < 0.05). after pyridoxamine treatment a significant difference in relation to the c group was no longer observed, despite that no significant differences were observed between mg and pyr groups (figure 5(b)). this study investigates the scavenger properties and beneficial actions of pyridoxamine in methylglyoxal - induced microvascular damages in the adipose tissue. the significant alterations of hdl cholesterol, free fatty acids, cel, pas staining, tgf- precursor, masson trichrome staining, bcl-2/bax ratio, and partially vwf were reverted by pyridoxamine. in accordance with previous reports from our laboratory, mg administration during 8 weeks did not have significant alterations in body weight, glycemia, and hba1c [1, 7 ]. once no alterations were found in the glucose metabolism, the lesions observed after mg treatment are only due to direct mg effects. however, mg administration increased systemic free fatty acids levels, suggesting adipose tissue dysfunction, due to a higher rate of lipolysis. these results are also in accordance with our previous observations after mg treatment during 14 weeks. as demonstrated before in zucker diabetic rats (zdf) [13, 15 ], pyridoxamine effects led to lower systemic levels of free fatty acids. our previous and present results show that mg treatment leads to decreased serum adiponectin levels, but these effects may be acquired during the time, as they are significant only after 14 weeks of mg administration [1, 7 ]. mg treatment during 8 weeks may have a lower impact on adiponectin levels, or the effects may have been lost because the rats were kept with water during 4 weeks after mg treatment. previously, correlation between cel levels and mg administration was observed in the aorta of spontaneously hypertensive rats and in retina of glo1 transgenic rats. as expected, mg administration during 8 weeks led to increased cel levels and accumulation of pas - positive material in adipose tissue, in accordance to previous reports [1, 17 ]. however, 8 weeks of mg treatment were not sufficient to induce major alterations in rage levels in adipose tissue, what is in accordance with previous data from our laboratory (unpublished data). however, that kind of effect was observed in aorta after 14 weeks of mg administration. previous in vitro studies from onorato and colleagues showed that pyridoxamine inhibits ages formation as well as subsequent protein modifications, features commonly observed in type 2 diabetes. several authors described that pyridoxamine inhibits age formation through the reaction with and scavenging of dicarbonyl intermediates [11, 19 ]. the role of pyridoxamine in decreasing age formation in in vitro systems and in different animal models, including stz - induced diabetic rats and zdf rats, was also observed. in accordance, in our study the treatment with pyridoxamine during 4 weeks after mg administration caused a significant decrease of cel levels and pas - positive components in adipose tissue. in vivo studies using wistar rats showed an increase of tgf- in glomerular, tubular, interstitial, and endothelial cells of the kidney. in vitro, collagen glycation caused by mg stimulates the differentiation of human cardiac fibroblasts to myofibroblast, in a tgf--dependent manner. as well, we reported that mg administration during 14 weeks also led to increased tgf- expression, as well as increased masson trichrome staining. in the present study, we show that even after 8 weeks of mg treatment a higher accumulation of masson trichrome components occurred. in vitro studies with pyridoxamine revealed that it protects from mg - induced integrin binding and cell adhesion, a major event of vessel thickening. here, we show that the treatment with pyridoxamine decreased the expression of tgf- precursor and inhibited the accumulation of masson trichrome - positive material, suggesting a causal role between increased glycation markers and profibrotic responses. colocalization of tgf- and vwf suggests tgf- expression to occur mostly in blood vessels regions. this demonstrates the presence of fibrosis in the microvasculature of adipose tissue, what may be an important factor for local microvascular lesions. the ratio between bcl-2 and bax decreased after mg treatment, what is in accordance with several reports from our and other laboratories [1, 21, 22 ]. our group demonstrated that decreased bcl-2/bax ratio is associated with increased endothelial cell death and higher vessel dysfunction in the retina. furthermore, we demonstrated that this event is also related with decreased blood supply to adipose tissue, what may lead to hypoxia, a major contributor to adipocyte dysfunction. pyridoxamine was observed to prevent cell death by apoptosis in the human lens epithelial cell line hle - b3 and in the cataractous lenses of zdf rats, through the inhibition of argpyrimidine formation [5, 23 ]. in b6 db / db mice, a model of type 2 diabetes, pyridoxamine decreased the progression of established diabetic nephropathy. as mentioned, we previously reported that mg administration during 14 weeks causes a decrease of blood supply to the adipose tissue, mainly through increased endothelial cell death and impaired angiogenesis. in this study, we show that these effects were similar after 8 weeks, although more modest. despite pyridoxamine was effective in the reduction of most of the lesion markers, it was not able to significantly raise adipose vwf levels in relation to mg - treated rats. however, vwf levels were no longer decreased in relation to control rats, suggesting a partial effect. we show that reducing adipose tissue glycation and fibrosis using pyridoxamine may be a useful strategy to improve adipose tissue microvascular lesions. | background and aims. adipose tissue dysfunction results from many factors, including glycation - induced microvascular damages. we tested the usefulness of inhibiting methylglyoxal - induced glycation to adipose tissue microvasculature in this work, using the antioxidant and dicarbonyl scavenger drug pyridoxamine. methods. a group of wistar rats was treated daily with methylglyoxal (mg, 75 mg / kg / day, 8 weeks). half of this group was treated with pyridoxamine in the following 4 weeks (pyr) (100 mg / kg / day) and the other half did not have any further treatment (mg). a group of wistar rats without mg treatment was used as control (c). results. mg group showed decreased hdl cholesterol and increased plasma free fatty acids levels, what was reverted by pyridoxamine. mg also caused an increase of tissue cel levels (glycation marker), as well as increased staining of pas and masson trichrome - positive components. pyridoxamine led to cel and tgf- levels similar to those observed in control rats and inhibited the accumulation of pas and masson trichrome - positive components. mg caused a decrease of bcl-2/bax ratio (marker of apoptosis) and vwf staining (microvascular marker), what was partially reverted by the treatment with pyridoxamine. conclusions. preventing methylglyoxal - induced accumulation of glycated and fibrotic materials using pyridoxamine improves the microvascular lesions of the adipose tissue. |
audiology is a field of study dealing with assessment, diagnoses, treatment, rehabilitation, and prevention of hearing and balance disorders. it is generally accepted that one of the main purposes of audiology is to improve human communication by providing audiology services and establishing an effective multi - sector collaboration, as a major field of communication sciences and disorders (csd) with speech - language pathology. in recent years, the global audiology market is increasing due to a rapid population growth of age - related hearing loss. the use of standardized and consistent terms is integral in minimizing difficulties in comprehension and interpretation across stakeholders. although a number of csd terminology projects have been conducted over the last 40 years, challenging issues still remain unresolved. walsh described several factors contributing to the inconsistent terminology in csd, centering on speech - language - pathology. these include complexity of human communication, lack of models of disability, and multiple views among stakeholders. relevant to the walsh 's study, the international group on terminology framework for communication sciences and disorders (igotf - csd, 2006) undertook to improve the " appropriateness, accessibility, and consistency " of terminology issues in csd, considering both professional and public sectors. the project mainly emphasized establishing an international collaboration, initiating professional awareness, identifying terminology related issues for documentation, and developing terminology frameworks in csd. compared to most previous studies focusing on terminology issues in speech - language pathology of csd, consistent and appropriate terminology in audiology is very important to develop professional disciplines because the use of inconsistent terms in audiology disrupts communication with other professionals, diagnostic evaluation, and documentation. for these reasons, the establishment of standardized terms among professionals to improve communication represents an important challenge for audiologists and relevant professionals. the present report provides an overview of terminology studies in audiology including topics and study characteristics, as well as categorizing the main issues. the goals are to improve the understanding of the current issues for audiology terminology and to provide some basic information that will be useful to develop an international standard. phase 1 included a systematic electronic searches using medline (pubmed), excerpta medica database, cumulative index to nursing and allied health literature, and international organization for standardization. electronic databases were searched using keywords related to terminology of audiology : ' terminology of audiology, ' ' terminology of hearing loss, ' ' terminology of hearing impaired, ' and ' terminology of communication sciences and disorders. ' the studies were initially identified according to the titles of 2921 publications following careful abstract examination. of these, whole texts of 16 publications were retrieved. five papers met the inclusion criteria described below and were further investigated (table 1). in phase 2, a manual search was conducted to collect additional publications with keywords related to terminology project in audiology. a total of 16 papers were found (table 1). to investigate potential terminology issues in audiology, english - language publications including peer - reviewed journals, editorials, routine publication, resources, guidelines, or standards published between 1980 and 2015 were considered, as was terminology in audiology or csd as a major study topic or subject. qualitative analysis was performed to identify demographics, characteristics, and topics of the publications. table 2 displays a summary of the publications including overall study topics and essential terminology issues in audiology. twelve studies were review or discussion type publications and the other four included grounded theory, chart review and cross - sectional studies. among the 16 studies representing terminology related topics in csd, six papers directly focused on terminology issues in audiology. keywords of the publication also confirmed these five main issues of terminology in audiology (table 3). specific audiology terms and definitions discussed for improved practices were ' auditory processing disorders, ' ' hearing disorders, ' hearing loss, ' ' nonorganic hearing loss, ' and ' sensorineural hearing loss. ' in addition, three studies suggested the possible emergence of international classification of functioning, disability and health (icf) as a conceptual model of terminology in csd. the study topics of terminology in audiology comprised terms and definitions, terminology model / framework, and challenging terminology issues. five main terminology issues in audiology categorized were appropriateness, classification / framework, inconsistency of terminology, multilingual / international aspects, and service quality / delivery including communication and accessibility issues. the igotf - csd project launched terminology project in csd to improve the appropriateness, accessibility, and consistency of terminology. in a practical way, the eurotermbank project established extensive multilingual terminology networks including audiology category and emphasized the terminology management goals with " high quality of general terms, harmonization, exchangeability, and availability ". these projects addressed recurring terminology is sues including inconsistency and accessibility and five main issues in present study showed somewhat similar problems. however, compared to the recurring terminology issues in audiology, the present study indicated the lack of studies and standards directly related to terminology in audiology, and the lack of professional awareness and normalized terms in audiology. one term- and definition - based approach focused on the use or establishment of common standardized terms. the euro termbank project addressed the importance of standardized terminology, centering on consistency and appropriateness of terms. it also provided methodological information leading to national and international consolidation to resolve terminology issues and establish standardized terms. developing common standardized terms may depend on clarification, consensus, and harmonization of existing terms and underlies best practice and effective communication for both professional and public sectors. in other words, establishing appropriate terms with high quality and consensus supports the use of unambiguous and consistent terms and definitions, thereby improving diagnostic evaluation and minimizing communication difficulties. on the other hand, this approach provides systematic and conceptual structures of terminology and considers various possible uses, relations, and interactions among relevant stakeholders to improve overall underlying issues in terminology. walsh 's model advocating the igotf - csd project emphasized two primary stakeholder distinctions between profession - specific terminology and public terminology. profession - specific terminology considers diagnostic purposes, descriptive purposes, research purposes, tentative clinical labels, and discredited labels. public terminology focuses on service delivery purposes, lobbying and advocacy purposes, and political and legislative purposes. a biopsychosocial model of icf was suggested as a universal framework to establish consistent terms for appropriate assessments and documentations. the collective data indicate that the use of consistent terminology is an underlying factor to improve terminology issues in audiology. furthermore, improving service quality and delivery depends on the use of consistent terms, effective communication, easy accessibility, and positive impacts on ongoing interactions of multiple stakeholders including professionals, clinicians, patients, and administrators. for these reasons, achieving national and international consensus and harmonization will help resolve various terminology issues in audiology. in other words, establishment of standardized terminology in audiology may minimize current challenging terminology issues by improving appropriateness and consistency of terminology as well as communication among relevant stakeholders at national and international levels. | the present report provides an overview of terminology studies in audiology including topics and study characteristics, as well as categorizing the main issues. the goals are to improve the understanding of the current issues for terminology in audiology and to provide some basic information that will be useful to develop an international standard. search procedures were completed over two phases. phase 1 included a systematic electronic searches using medline (pubmed), excerpta medica database, cumulative index to nursing and allied health literature, and international organization for standardization with keywords related to terminology of audiology. the studies were initially identified according to the titles of 2921 publications following careful abstract examination. of these, whole texts of 16 publications were retrieved. five papers met the inclusion criteria were further investigated. in phase 2, a manual search was conducted to collect additional publications with keywords related to terminology project in audiology. a total of 16 papers were found. the essential terminology issues classified included ' appropriateness, ' ' classification / framework, ' ' inconsistency of terminology, ' ' multilingual and international aspects, ' and ' service quality / delivery including communication and accessibility. ' this was indicative of the paucity of terminology research in audiology, despite recurring terminology issues. establishment of standardized terminology in audiology may minimize current challenging terminology issues by improving appropriateness and consistency of terminology as well as communication among relevant stakeholders at national and international levels. |
the leachate has to be treated in a downstream waste water treatment plant, and it is necessary to identify toxicity causative chemicals for the effective treatment. accordingly, methods were developed to assist in identifying effluent toxicants, and these methods are well known as a toxicity identification evaluation, tie. tie methods have been proven to be effective tools for characterizing and identifying toxicants in samples of effluents and other complex mixtures. two types of tie, treatability - based tie and chemical - specific tie, have been studied so far. treatability - based tie is a general approach in tie to determine the effective water treatments and (if possible) thereby speculate the toxicity - controlling chemical(s). chemical - specific tie was developed to evaluate the toxicity - contributed chemicals more simply. the approach is to compare chemical analysis data with concentration of chemicals to express toxicity (e.g., lc50, ec50 (the lethal or effective concentration for 50% of test organisms), etc.). first, in the treatability - based tie, when the chemical which highly contributed to the toxicity was included in the sample, the toxicity of other chemical can not be detected by the tie based on a single toxicity test. second, in the chemical - specific tie, when concentration of many chemicals were higher than lc50 or ec50, toxicity causative chemicals for effective treatment can not be identified. ionized and un - ionized forms of the compounds such as heavy metals have different toxicity to the organisms. the ionizable compounds are commonly found in landfill leachate including ammonia and some organic compounds as well as heavy metals. in addition, ph affects metal toxicity through changes in solubility and speciation [3, 4 ]. contribution rate is one of the quantitative approaches to solve the above - mentioned problems. the contributions of each component were calculated as quotients of concentration, though contribution rate has not been used for identification of toxicity - causative chemicals. therefore, contribution rate approach for identification of toxicity causative chemicals can consider the effect of ph in landfill leachate toxicity for more effective treatment. this manuscript describes toxicity testing and tie studies conducted on industrial waste landfill leachate. through this case study, we describe the problems of tie testing used to characterize, identify, and confirm ammonia as the cause of acute toxicity to the daphnia magna. the objectives of this study are to perform contribution rate approach for identification of toxicity causative chemicals considering the effect of ammonia toxicity changing by ph, and to detect toxicity causative chemicals other than ammonia with the contribution rate approach. two effluents were collected from the same landfill site in japan in 2008 and 2009. the landfill site for final disposal of industrial wastes has already been closed since the 1990s. metal concentrations were determined with an icp - aes (sii sps7800) in landfill leachate in 2008, and an icp - ms (agilent 7500s, yokogawa) in landfill leachate in 2009. the ammonium ions and other ionic chemical parameters (f, cl, no2, br, so4, na, k, mg, and ca) concentrations were determined by using an ionic chromatograph (tosoh ic-2001). total organic carbon concentration (toc) was also analyzed by using a toc analyzer (toc-5000a, shimadzu). before these physico - chemical analysis, samples were filtered with a 0.45 m paper filter. in icp - aes, samples were acidified with twentyfold diluted 65 wt% nitric acid. acute tie studies began with a full phase i toxicity characterization as described by usepa. this procedure involves some different tests, which evaluate the effect of physical / chemical manipulations on effluent toxicity. comparing the toxicity of manipulated samples with that of unmanipulated effluent provides information on the physical / chemical properties of the specific toxicant(s). baseline effluent toxicity test was conducted at effluent dilutions of 100 vol%, 50 vol%, 25 vol%, 12.5 vol% and 6.25 vol%. ph adjustment was used throughout phase i to provide more information on nature of the toxicants. changes in ph can affect the solubility, polarity, volatility stability, and speciation of a compound, thereby affecting its bioavailability as well as its toxicity. one molar of naoh or 1.0 m hcl was added dropwise to the samples to control the ph near 11 or 3. the aeration test is designed to determine how much effluent toxicity can be attributed to volatile, sublatable, or oxidizable compounds. the ph of the acidic and basic effluent and dilution water aliquots should be checked every 5 min during the first 30 min of aeration and every 10 min thereafter. if the ph 3 or ph 11 solution drifts more than 0.2 ph units, it must be readjusted back to the nominal value. the graduated test ph test was also modified by performing the test at ph 6.5, 7.5, and 8.5. since ammonia toxicity significantly varies over this range of ph values, the relative difference in toxicity could still be examined. edta is a strong chelating agent, and its addition to water solution produces relatively nontoxic complexes with many metals. oxidant reduction test was designed to determine to what extent constitutes reduced by the addition of sodium thiosulfate are responsible for effluent toxicity. concentration of sodium thiosulfate equal to and lower than the thiosulfate lc50 for test species being used are added to several containers with effluent at the 100% concentration. in addition to the phase i manipulations described by usepa, other manipulations were conducted to further characterize the effluent toxicant(s). filtration manipulations tests were conducted (mf = microfiltration ; pore diameter 0.45 m, uf = ultrafiltration ; membrane area 0.40 m pressure 0.40 mpa (rf002040, advantec mfs, inc. tokyo, japan), ro = reverse osmosis ; membrane area 0.40 m pressure 0.40 mpa (rf000670, advantec mfs, inc. in aqueous solution, un - ionized ammonia (nh3 (aq)) exists in equilibrium with the ammonium ion (nh4) according to the dissociation equation : (1) nh4++h2okanh3(ap)+h3o+. the toxic effect of total ammonia increases with increasing ph, indicating that the un - ionized ammonia is the main toxic form. un - ionized ammonia concentration was calculated by using ion speciation analysis software mineql+ (environmental research software) and ammonium ion concentration measured in this study. to specify the ammonia toxicity, samples with pure ammonium chloride were adjusted in terms of ph at 7.0 and then the toxicity was tested with d. magna. d. magna acute test was performed according to oecd guideline 202, at adjustment of ph using diluted naoh or hcl solution. test organisms originated from a healthy d. magna clone which has been cultured in the laboratory under standardized conditions in the iso test solution (2.00 10 m cacl2, 5.00 10 m mgso47h2o, 7.70 10 m nahco3, and 7.71 10 m kcl). acute toxicity was assessed by noting the effects of the test compounds on the effective concentration of d. magna. d. magna were exposed to each landfill leachates, ammonia, and bisphenol a for 48 hour of exposure duration. the acute toxicity endpoint was determined as the lc50 of a chemical that causes 50% of reduction of d. magna survival. the toxicity of the target chemicals have been evaluated as the influence of matrix effects for the determination of lc50 values. the logistic dose response relationship is described as follows : (2)r=1001+(x / x50), where r = biological response as percentage of the mortality rate of d. magna, x was concentration of toxicant, and x50 was the concentration of poison that resulting 50% reduction of survival in d. magna, is the shape parameter of the dose response curve. a simple model to describe the toxicity of a protolyzing substance is based on its dissociation and the addition of each form in the dissociation : (3)1lc50, tot=1lc50,nh4+(1lc50,nh4+1lc50,nh4+(aq)) kaka+ch+. lc50,tot, lc50,nh3(aq), and lc50,nh4 were 50% effective concentration expressed as total ammonia, un - ionized ammonia and ammonium ion, respectively, ka was stability constant for nh3 and nh4, ch was concentration of hydrogen - ion. from a linear fit with data of the toxic effect as 1/lc50,tot against dissociation expressed as dissociation of ammonium, the toxicity of the un - ionized ammonia is obtained from the intercept, and the toxicity of the ammonium ion is obtained from the slope and the intercept. the toxic contribution of the specific toxicants in the landfill leachate was derived by calculations of contribution rate at the lc50 concentration of the leachate (% v / v). first, the concentrations of toxicity causative chemicals were measured in the landfill leachate (measured), then the concentrations of the the toxicity causative chemicals in the lc50 mixture (mixture) were calculated. then, for each toxicity causative chemicals, the mixture was compared with the specific lc50 of each toxicity causative chemicals : (4)landfill leachate lc50,nh4 + or nh3(aq)lc50,nh4 + or nh3(aq)100 = contribution on rate of nh4 + or nh3(aq) [vol% ]. table 1 shows physico - chemical analysis of industrial waste landfill leachate and lc50 values of each chemical components for d. magna. landfill leachates showed high ammonia concentration and elements of salinity concentration, such as potassium and sodium. additionally, heavy metal concentrations in both landfill leachate samples were lower than each lc50. physico - chemical analysis data with lc50 value in each components were compared for chemical - specific tie approach, then the results showed that heavy metals were not toxicity causative chemicals. unfortunately, many kinds of toxicity causative chemicals were derived by the chemical - specific tie approach. another trial on the chemical - specific tie performed by shoji. provided precious information on the toxicity - controlling chemicals in landfill leachates. twenty - five landfill leachate samples were examined by a toxicity test and chemical analyses. by comparing two important parameters describing dose - response relationship (the ec50 value and the slope) between landfill leachate sample and 255 kinds of chemicals, possible candidates of toxicity - controlling chemical were listed as bisphenol a and other phenols. subsequently performed chemical analyses successfully showed the presence of such chemicals, and the concentration of these chemicals partly explained the observed toxicity. in order to take an effective countermeasure for the waste landfill leachate, both chemical analyses and toxicity tests can provide important information to find the targeted and cost - effective water treatment. figure 1 shows results of acute phase i characterization testing with a d. magna immobilization test. the baseline lc50 for d. magna was approximately 20 vol% of the landfill leachate. toxicity of solid phase extraction - treated leachate and edta - addition leachate were not reduced compared to that of untreated leachate. the acutely toxic landfill leachate was submitted for chemical analysis shown in figure 1 ; ammonia was detected in the sample, and the concentration was 361 ppm considerably in excess of concentrations to be toxic to d. magna. toxicity of manipulated sample relevant to ph - change was reduced relative to untreated leachate, reinforcing our suspicion that the toxicant was ammonia. in another case of treatability - based tie, stronkhorst. indicated that tests using graduated ph manipulations showed significant increase in toxicity from low ph to high ph in a sediment samples in silty marine harbor dominated by ammonia or sulfide. in terms of the influence of ph conditions on the proportion of ammonium ions to total toxicity of ammonia, it was necessary to perform the toxicity tests with d. magna at defined ph in order to elucidate the toxicity of ammonia. examples of concentration / response curves obtained in terms of ammonium chloride at ph 7.0 and 8.0 are shown in figure 2. un - ionized ammonia constituted the major source of toxicity in these investigations, even though volume of un - ionized ammonia comprised a small fraction of total ammonia, in term of a mixture of two toxic components at different proportions assuming additive effects of the two forms. the specific toxicity of un - ionized ammonia and ammonium ion were calculated from a plot of the inverse of lc50 versus the degree of dissociation (ka / ka + ch) according to (3) as shown in figure 3. the toxicity of ammonia and ammonium ion mixture increased upon increasing ph. from a linear fit with data of the toxic effect as 1/lc50,tot against dissociation expressed as dissociation of ammonium, the correlation coefficient (r) between observed plots and the linear function expressed as (1) was 0.93. the toxicity of the un - ionized ammonia is obtained from the intercept, and the toxicity of the ammonium ions from the slope and the intercept. the un - ionised ammonia toxicity (lc50,nh3(aq)) was calculated as 3.3 ppm and the toxicity of ammonium ions (lc50,nh4) was calculated as 222 ppm, that is, almost a factor 50 difference between (lc50,nh3(aq)) and (lc50,nh4). joint toxicity with these components have been observed by an algae nephroselmis pyriformis, within almost a factor 100 difference between (lc50,nh3(aq)) and (lc50,nh4). ammonium ion is slightly toxic among different species of ammonia, but concentration of ammonium ion was much more larger than that of un - ionized ammonia around ph 7. the contribution of ammonium ions in the total ammonia toxicity was therefore not negligible. according to some previous studies on mixture toxicity of chemicals, the multiple toxicity caused by two or more chemicals can be classified into three types, additive, synergistic, and antagonistic effects. the multiple toxicity of ammonia and ammonium ion can be assumed as an additive effect. as discussed above, information on multiple toxicity are too limited to discuss more on interaction among other heavy metals on organic chemicals such as bisphenol a. the contribution of each component in the landfill leachate toxicity were calculated according to (3), (4), and specific ammonia toxicity, and the results are presented in table 2. table 2 also indicates that ammonia is a main toxic constituent in the landfill leachate. treatability - based tie led the fact that toxicity causative chemical is only ammonia. in landfill leachate in 2008, contribution rate of ammonia toxicity was calculated as 58.7 vol%. the toxicity contribution of chemicals other than ammonia was calculated as 41.3 vol%. in landfill leachate in 2009, the sum of contribution rate and the lack of correlation to concentration does not allow a precise evaluation, because other components may interfere with the toxic action of ammonia. previous papers suggest that ammonia toxicity to amphipod and fish was strongly dependent on the ionic composition of the medium (e.g., potassium and sodium ion) [1113 ]. as a toxicity causative chemical other than ammonia, bisphenol a (bpa) was suggested by chemical - specific tie based on the concentration shown in table 2. table 2 shows the contribution of bpa toxicity in the total toxicity of landfill leachate. contribution rate of bpa toxicity was calculated as 8.21 vol% in landfill leachate in the year of 2008, 29.0 vol% in landfill leachte in the year of 2009. although bpa was one of the toxicity causative chemicals in the landfill leachate, bpa toxicity was not determined by the spe manipulation tests of treatability - based tie, because toxicity of ammonia was relatively large so that the toxicity of bpa was shadowed. according to the previous studies on the toxicity of bpa, the acute toxicity data showed that bpa was moderately toxic to the invertebrates tests. shoji. tried to find toxicity - controlling chemicals in waste landfill leachate and waste samples such as various sludges. according to their findings, bpa was found as possible candidates for toxicity - controlling chemicals in landfill leachate and parts of waste sludge samples, respectively. in addition, the contribution of ammonia to landfill leachate toxicity was already examined in a previous study. un - ionized ammonia was a more toxic form of ammonia and seemed to be the major toxicant for most leachates from 16 landfill sites. a methodology to decide toxicity causative chemicals in landfill leachate based on the toxicity contribution rate and the effect of ammonia toxicity changing by ph was developed in this study. the contribution of ammonia toxicity in the landfill leachate toxicity was calculated as 58.7 vol% of the total toxicity of the landfill leachate. contribution rate of the toxicity causative chemicals masked by ammonia toxicity was 41.3 vol% of the total toxicity of the landfill leachate. bisphenol a was one of the toxicity causative chemicals other than ammonia in this study. tie based on contribution rate approach developed in this study enables us to detect toxicity causative chemicals masked by high contribution chemicals independently of ph of landfill leachate. | toxicity identification evaluation (tie) phase i manipulations and toxicity test with d. magna were conducted on leachates from an industrial waste landfill site in japan. physicochemical analysis detected heavy metals at concentrations insufficient to account for the observed acute toxicity. the graduated ph and aeration manipulations identified the prominent toxicity of ammonia. based on joint toxicity with additive effects of unionized ammonia and ammonium ions, the unionized ammonia toxicity (lc50,nh3(aq)) was calculated as 3.3 ppm, and the toxicity of ammonium ions (lc50,nh4 +) was calculated as 222 ppm. then, the contribution of ammonia toxicity in the landfill leachate toxicity was calculated as 58.7 vol% of the total toxicity in the landfill leachate. other specific toxicants masked by ammonia 's toxicity were detected. contribution rate of the toxicants other than by ammonia was 41.3 vol% of the total toxicity of the landfill leachate. |
the index hpai - h5n1 was confirmed in nigeria at a commercial poultry farm in kaduna state, and, by the end of the initial outbreak, over 46,000 poultry [1, 2 ] had been destroyed. this outbreak brought the asian strain of highly pathogenic avian influenza (hpai) h5n1 into africa for the first time in the beginning of january, 2006 [37 ] in nigeria. since its emergence in africa in 2006, avian influenza viruses of the h5n1 subtype have spread rapidly to poultry farms in several african countries. it has caused deaths of millions of birds in africa, as is the case in other affected parts of the world. highly pathogenic avian influenza (hpai) is caused by aivs that are extremely virulent, causing up to 100% mortality in domestic chickens. the h5n1 highly pathogenic avian influenza (hpai) virus has been a great concern not only for the poultry industry but also for human health since 1997. following the index hpai - h5n1 in nigeria, several efforts have been directed to increased surveillance and diagnosis of the disease. this has led to increased diagnostic capacity, reporting, and research into the diverse genotype of h5n1 isolates from nigeria. the commercial poultry production system in nigeria as categorized by the fao, which stems from the two major systems : rural poultry production and commercial poultry production, was affected by the hpai outbreaks. also, several attempts were made to determine the losses in terms of the number of poultry, monetary, and social values as a result of the disease burden in nigeria. these attempts have been at some point in the course of the disease or aimed at a particular region of the country due to some identified constraints. also no overall, detailed clinical and pathological record has been given on a case by case basis for all the outbreaks as seen from different states and regions of the countries which could highlight factors involved in the spread of the disease. 2006, in their letter to the veterinary record, mentioned a few lesions seen in the index case. 2006 described the clinicopathological and husbandry features associated with the maiden diagnosis of ai in nigeria. other reports were limited to cases seen in 2006 [14, 15 ] only. 2007 had earlier reported lesions which depict circulatory disturbances, respiratory, intestinal, and reproductive system pathology in selected cases. this study aimed at achieving the determination of the losses on a state by state basis and the total losses recorded during the entire course of the disease in nigeria and also aimed at highlighting the morbidity, mortality, and pathology in the commercial poultry production systems as practiced in nigeria. all the data including state, location, farm flock size, and morbidity and mortality records used in this study were supplied directly by clients who reported and submitted carcasses of layers, pullet, cockerels, and broilers for postmortem examination and avian influenza diagnosis at the national veterinary research institute (nvri), central diagnostic laboratory, vom. a total of three hundred and sixteen (316) carcasses from one hundred and fifty - three (153) farms from eighteen (18) states and the federal capital territory, abuja, were examined. these carcasses were submitted directly by clients for postmortem examination and avian influenza diagnosis and were selected based on laboratory confirmation of hpai h5n1 virus infection at the nvri laboratory. carcasses of the commercial birds that died after natural infection with hpai were submitted for pathological examination. following postmortem examination of the carcasses, sections of liver, heart, spleen, kidney, lung, trachea, proventriculus, gizzard, duodenum, ileum, cecum, and brain were removed and fixed in 10% buffered formalin. all tissue samples were then embedded in paraffin, sectioned at 5 m, mounted on clean glass slides, and stained with hematoxylin and eosin (h&e) stains for histopathologic examination using low and high powered field of carl zeiss or nikon binocular microscope. virus isolation. for virus isolation, samples of liver, heart, spleen, kidney, lung, trachea, duodenum, and caecum were removed and submitted for virological investigation, where the homogenates of the trachea, lung, liver, spleen, and kidney were inoculated via the allantoic cavity into 911-day - old embryonating chicken eggs obtained from specific antibody negative chickens. during the period under review (20062008), a total of eighteen (18) states (adamawa, bauchi, bornu, jigawa, kaduna, kano, katsina, sokoto, plateau, nasarawa, kwara, lagos, ogun, oyo, rivers, edo, anambra, and enugu) and the federal capital territory, abuja, had confirmed hpai h5n1 outbreaks in commercial layer, pullet, cockerel, and broiler (table 1). a total of one hundred and fourteen thousand, nine hundred and twenty - nine (114,929) commercial chickens died from a total flock size of nine hundred and sixty - five thousand, five hundred and eighty - three (965,583) before the rest of the flocks were stamped out. the north - western region recorded the highest number of mortalities in commercially raised chickens as a result of natural infection with hpai in nigeria. the figure (69,741) represents 60.68% of the total number (114,929) of commercially raised chickens that died as a result of hpai (table 1). while the total number of chicken losses as a result of hpai death and stamping out in this region (438,386) was second to the south - western region where commercial bird losses totaled 445,320 and the number that died as a result of hpai when the reporting was done was 26,878, being 23.38% of the total number of commercial chickens that died as a result of hpai. mortality rates were the highest in broilers flocks (73.92%) and the least in layers flocks (11.11%). a breakdown of the figures, which showed layer flocks, has been the most affected commercial chicken type with a total bird loss of 939,620, representing 97.31% of the commercially raised chickens. of the 939,620 layer population affected in 127 farms, 104,351 layers, representing 90.79% of 114,929, died as a result of direct hpai infection in layer flocks. eight hundred and fifty thousand, six hundred and fifty - four (850,654) birds, which represent the difference between the flock size and the number of the dead, were stamped out. broilers were the second most affected commercial chicken type of which 6,433, representing 0.66% of the total flock size (965,583) of commercially raised chickens, were affected by hpai. of the 6,433 broilers affected, 4,755 broilers, representing 4.14% of the total number of commercially raised chickens (114,929), died as a result of direct hpai infection, while the remaining broilers were stamped out. pullets were the next affected commercial chicken type of which 16,421 (11.70%) were affected and 4408 (3.84%) were reported to be dead. cockerel was the least affected commercial chicken type of which 3109 (0.32%) were affected and 1,415 (1.23%) were reported to be dead. main clinical and pathologic findings were observed in the nervous, circulatory, respiratory, integumentary, musculoskeletal, gastrointestinal, and reproductive systems and occasionally lesions are multisystemic. signs observed and reported are sudden death, high mortality, weakness, and recumbency. others ranged from nasal discharges, dyspnea, coughing, sneezing, diarrhea, shank hyperemia and haemorrhage, inability to stand, ataxia, and torticollis. in layers, egg structural abnormalities such as shell - less egg, white - colored eggs, and soft eggs were reported. lesions observed in the circulatory system included congestion (figures 1 and 2) and cyanosis of comb and wattle, comb and wattle edema, and facial and subcutaneous edema. within the respiratory system, there were airsacculitis and pneumonia. there was petechiation to ecchymoses of the proventricular (figure 3) and intestinal mucosa with resultant enteritis in the gastrointestinal system. integumentary system lesions are mainly cyanosis, edema, and ecchymotic hemorrhages while there were inflammatory, degenerative, and necrotic lesions in the musculoskeletal system. in adult birds, mainly layers reproductive lesions were observed and they were mainly ovarian follicular ecchymotic hemorrhages (figure 4). layers. most of the commercially raised layers (67%) exhibited lesions of the circulatory system, mainly cyanosis of comb and wattle with occasional facial edema. only 20% showed nervous signs and brain lesions of neuronal and purkinje cell necrosis of cerebrum and cerebellum, respectively. respiratory lesion of airsacculitis and pneumonia (figure 4) with vascular congestion (figure 5) was evident in 43.5% with more than half having pneumonia. of the 70 clinical reports of diarrhea, only 42 had enteritis and 18 were hemorrhagic. enteric petechiation and ecchymoses were observed in 45 of the carcasses while pancreatic necrosis was occasionally encountered (figures 6 and 7). splenic necrosis and loss of lymphoid cells were also seen in the carcasses (figure 8). a few carcasses (6.4%) showed integumentary system lesions ; these are mainly cyanosis, edema, and ecchymotic hemorrhages. reproductive lesions were only observed in these layers, and these were observed in 15.3% only. these were mainly ovarian follicular ecchymotic hemorrhages and structure abnormality. shank hyperemia (figure 9) and haemorrhage were also frequently seen. pullet. of the twenty - five (25) pullet carcasses examined, 60% had report of the circulatory system signs, mainly cyanosis of comb and wattle with occasional facial edema. only 4% showed nervous lesion in the brain such as neuronal and purkinje cell necrosis of cerebrum and cerebellum, respectively. respiratory lesions of nasal exudation, airsacculitis, and pneumonia were evident in 32%. enteric lesion was observed in 3 (12%) of the 25 carcasses examined. twenty - eight (28) percent had muscular and shank hemorrhages with necrosis, and/or myositis. twenty - four (24) percent of the pullets which died suddenly were from flocks with high mortality and also had multisystemic lesions. no lesion was observed in the integumentary and reproductive systems, respectively, in all carcasses examined. broiler. of the twenty - nine (29) broiler carcasses examined, 82.7% had lesions of the circulatory system, mainly cyanosis of comb and wattle with occasional facial edema. only 4 (13.7%) showed brain lesions of neuronal and purkinje cell necrosis of cerebrum and cerebellum, respectively. ten (34.4%) of the broilers which died suddenly were from flocks with high mortality and had multisystemic lesions. no lesion was observed in the integumentary and reproductive systems, respectively, in all carcasses examined. cockerel. of the fourteen (14) cockerel carcasses examined, 64% had lesions of the circulatory system, mainly cyanosis of comb and wattle with occasional facial edema. only 5 (35.7%) showed nervous lesions of neuronal and purkinje cell necrosis of cerebrum and cerebellum, respectively. five (35.7%) of the pullets which died suddenly were from flocks with high mortality and had multisystemic lesions. the north - western region recorded the highest number of mortalities in commercially raised chickens as a result of natural infection with hpai in nigeria. this represents 60.68% (69,741) of the total number of chickens which died as a direct result of hpai infection. the total number of chickens which died as a direct result of hpai infection and those that were stamped - out in this region was 438,386, only second to the total number of chickens which died as a direct result of hpai infection and those that were stamped out in the south - western region which stood at 445,320. indeed, south - western nigeria, particularly the states surrounding the city of lagos, holds much of nigeria 's poultry industry. it is estimated that over 65% of nigeria 's commercial poultry are located in the five southern states of lagos, ogun, oyo, osun, and ondo. a very high number of poultry deaths and losses were also reported in a north - western regional avian influenza investigation in the north - western region, apart from the fact that it was in this region where the first outbreak of hpai in nigeria was reported [4, 18 ] in a farm that had predominantly commercial birds [2, 14 ]. although the total poultry losses were higher in the southwest region, the total number of chickens which died as a direct result of hpai infection was 26,878 being 23.38% of the national total number of commercially raised chickens that died as a direct result of hpai infection, as compared with 60.68% (69,741) in the northwest. this difference may be as a result of the fact that the farms in the southwest are more organized and densely stocked as compared with those in the northwest which are not well organized and not as densely stocked. the finding of high mortality in the north - western states is consistent with earlier reports [2, 13 ]. in the north - western regional analysis which excluded bird losses in sokoto state, four hundred and eighty thousand, three hundred and seventy - eight (480,378) birds were reported as being lost as a result of hpai incursions and stamping out. the deviation of this finding from ours may be as a result of nonseparation between the various sectors of poultry production systems, as it includes backyard flocks and noncommercial and commercial flocks. the north - central states had a mortality of 6418 (5.58%) being the total number of commercial chickens that died as a result of hpai when the reporting was done, while the total number of chicken losses as a result of natural death and stamping out policy in this region was 31,189. the south - south region lost more birds to direct hpai infection (5309) as compared to the north - eastern region (4880) but more birds (29586) were destroyed in the northeast than in the south - south where 7,700 birds were destroyed. the southeast lost the least number of birds to hpai (1703) but had a high number of birds ' losses to hpai and stamping out (13402). under the commercial poultry production sector practiced in nigeria, the commercial layer - type chicken was the most hit by the highly pathogenic avian influenza outbreaks experienced by the nigerian poultry industry. with a total flock size of 939,620 lost in 127 farms having confirmed outbreaks, this is attributed to the large number of laying birds in individual flocks as compared to other chicken types under these sectors. this significantly affected the economy not only because a whooping sum of n631 million (us$5.43 million) was paid as compensations to farmers but also because laying hens contribute huge resources to the national poultry flock and this emphasizes the importance of commercial layer flocks for nigeria 's economy. it was also observed that the average mortality rate was the least in commercial layers (11.11%) and the highest in broilers (73.92). this may be as a result of the cage housing of commercial layers which restrict movement and contact between hpai infected ones and noninfected ones compared with broilers raised in deep litter and which also share water and feed sources. average mortality rate was higher in cockerels (males = 45.51%) than in pullets (females = 26.84%). the necropsy finding observed in the 316 carcasses examined of which 248 were commercial layer, 25 were pullet, 14 were cockerel, and 29 were broilers cut across more than one system and occurred more frequently and severely and in most of the carcasses examined irrespective of chicken type. in commercial layers, the systems affected included mainly circulatory, respiratory, and intestinal systems as observed by earlier investigators from the index case of hpai [2, 4 ] in nigeria. only 20% of the 248 layer carcasses had neurologic signs and lesions contrary to what was observed in the index case where only young stocks had nervous system signs. also, other investigators reported presence of nervous signs and lesion with no particular reference to age and with reference to adult birds. eighty - two percent (82.7%) of the broilers showed signs and lesions of circulatory disturbances followed by 67% in layers. this work was able to document the total hpai bird losses in commercially raised chickens in nigeria on a state by state cases and region by region cases, previously unreported. it also showed that mortality was the highest in broiler and males (cockerels) had more death than females (pullets). this study was able to document the losses in hpai infected commercial chickens in nigeria and the overall pathological findings of hpai infection in chickens in nigeria previously unreported. | commercial layer - type, pullet, cockerel, and broiler chicken flocks infected with highly pathogenic avian influenza (hpai) h5n1 in nigeria between 2006 and 2008 were investigated for morbidity, mortality, and pathology. of the one hundred and fifty - three (153) farms confirmed with hpai infection, one hundred and twenty - seven (127) were layer - type farms, nine (9) were pullet and broiler farms each, and eight (8) were cockerel rearing farms. this study revealed the morbidity and mortality of a total of 939,620 commercial layer chickens, 16,421 pullets, 3,109 cockerels, and 6,433 broilers. mortality rates were 11.11% in commercial layers, 26.84% in pullets, 45.51% in cockerels, and 73.92% in broilers in a total of eighteen (18) states and the federal capital territory, abuja. a total of 316 carcasses were examined of which 248 were commercial layer, 25 were pullet, 14 were cockerel, and 29 were broiler. main clinical and pathologic findings were observed in the nervous, circulatory, respiratory, integumentary, musculoskeletal, hemopoietic, gastrointestinal, and reproductive systems and, occasionally, lesions were generally nonspecific and multisystemic. lesions occurred more frequently, severely, and in most of the carcasses examined, irrespective of chicken type. |
although typically thought to occur in older individuals, a hooked acromion causing shoulder impingement symptoms in younger populations is less recognized. this report illustrates a case of type iii acromial impingement in a younger athlete and the importance of early imaging in refining diagnosis. a 31-year - old right - hand dominant cross - fit personal trainer presented to an outpatient clinic complaining of left shoulder pain worsening over a 2-year period. the pain had become intermittently worse over the last 6 weeks, and was particularly flared the day following handstand push - ups and kipping. pain was reportedly worsened by shoulder abduction beyond 90, bicep hammer curls and eccentric bench press. the patient perceived the left shoulder to be more elevated than the right at rest, and he had begun to note joint crepitus on circumduction. the pain was focal to the anterior aspect of the deltoid and upper biceps region with an occasional pulling sensation in the distolateral biceps. the patient was perplexed as to why the left shoulder was painful when he was right - handed. he described a 38/10 baseline daily pain, increasing to 10/10 with bicep curls and eccentric bench press. he pain with activities of daily living such as removing his shirt, lifting his 2-year - old child, and he was unable to sleep on his left side. despite the pain he took no medications, had no reported drug allergies or prior reactions to anesthesia. he was a non - smoker, and had been engaged in professional power lifting since 2008. cervical spine ranges of motion were pain free and the spurling 's test with extension was negative. a painful arc was present upon left shoulder abduction with hitching a reported pain at 90. there was, however, no palpable or audible crepitus on left shoulder circumduction. however, there was a focal area of tenderness upon palpation 3 cm proximal to the left lateral epicondyle. mill 's & cozen 's tests were negative, and resisted muscle testing of the common extensor origin and extensor carpi radialis brevis was unremarkable. the left proximal biceps tendon and medial aspect of the left acromial - clavicular joint (acj) was focally tender on palpation. the initial diagnostic impression was of chronic left shoulder impingement (query subacromial bursal effusion, early rotator cuff (rc) tear, down - sloped acromion), and mild acj osteoarthritis. although the physical examination was generally unremarkable, the history was indicative of some mild left extensor origin biceps tendonopathy. the patient was referred for a non - contrast magnetic resonance imaging (mri) of the left shoulder. the study reported high signal intensity within the belly of the supraspinatus muscle belly and tendon associated with a type iii downward - sloping acromion, which was interpreted to be causing a degree of impingement. there was also a small amount of fluid in the subacromial space raising the possibility of associated subacromial bursitis (fig. the report of imaging findings and prognostic discussion convinced the patient of the importance to alter the intensity of his upper body training activities. by simply avoiding repetitive overhead activities and modifying the intensity of his upper body exercise program, impingement symptoms abated considerably over a period of several weeks. as the patient was responding to conservative management and there was no evidence of rc tear on imaging, surgical referral was postponed. there are several functional and potentially reversible causes of shoulder impingement syndrome. however, identifying the presence of bony impingement of the subacromial space may aid in a better understanding of predispositions to rc pathology. the original bigliani acromial morphology classification of type 1-flat, type ii - curved and type iii - hooked has more recently in updated by vanarthos and monu, to include a type iv - convex morphology (fig. some studies have identified a significant association between type iii acromial morphology and full thickness rc tears. although type iii acromion (t3a) may be rare in asymptomatic young athletes, the incidence of in a general population of both young and older individuals is still not completely understood. typically, older patients are noted to have a high incidence of t2a and t3a (93% of those over 70) and both of full and partial - thickness rc tears were more commonly with these morphologies than type i. neer concluded that 95% of rc tears are caused by mechanical impingement, associating rc tears with extremely hooked (> 43) anterior acromial slope. other studies have looked at the lateral extension and angulation of the acromial slope also being important in diagnosing and managing impingement pathologies. although thought to be associated with older populations, t2 down - sloped and t3 hooked acromial impingement may occur in younger populations such as overhead athletes. impingement may be manifested by pain with overhead activities, shoulder weakness and decreased range of motion. early shoulder x - rays including the outlet y view to define acromial morphology, or mri imaging may help to refine diagnosis, prevent inappropriate therapies, understand prognosis and expedite more effective management strategies. appropriate surgical referrals are patients with subacromial impingement syndrome refractory to 36 months of appropriate conservative treatment. | down - sloped or hooked acromion morphologies may cause bony encroachment on the soft tissues of the subacromial space, predisposing to shoulder impingement syndrome. of the latter, a hooked or type iii acromion (t3a) has also been linked to rotator cuff (rc) pathology. however, as bony acromial impingement is typically thought to occur over the age of 40, its occurrence in younger shoulder athletes presenting with shoulder pain, impingement and rc pathology may be overlooked. this case serves to illustrate the occurrence of t3a in a younger shoulder athlete, and the importance of early imaging in achieving diagnostic accuracy. appropriate surgical referrals are patients with subacromial impingement syndrome refractory to 36 months of appropriate conservative treatment. surgery may be particularly beneficial in patients with a t3a. |
sexual dysfunctions (sds) frequently affect the elderly and can lead to dissatisfaction with interpersonal relationships and have an adverse impact on overall well - being and mood. sds include erectile dysfunction, orgasmic dysfunction, lack of sexual desire, dissatisfaction with intercourse, etc.. among these, the majority of patients of both sexes report a lack of sexual desire, and men, especially, report erectile dysfunction. epidemiological data have shown that about 40% 45% of elderly women and 20% 30% of elderly men may have sds. furthermore the prevalence of sds in men younger than 40 years of age has been reported to be 2% whereas that in men over 80 years of age has been reported to be 86%. therefore, many patients with sds tend to seek current medical intervention for management of their sds, especially erectile dysfunction (ed), such as medication, intraurethral suppositories or intracavernosal injeccasetions, implantation of a penile prosthesis, and hormonal therapy or psychotherapy. pharmacopuncture as a new and unique modality of treatment in korean medicine has had a promising effect on many kinds of diseases. however, until now, the focus of experiments and case reports has been musculoskeletal diseases, and to the best of our knowledge, no studies on the use of pharmacopuncture to treat sds exist. therefore, this study reports one case of sexual dysfunction (sd) treated with only sweet bee venom (sbv) pharmacopuncture. a 51-year - old man complaining of sd was administered udenafil (phosphodiesterase 5 inhibitor) for 15 days. he had low back pain since 2009, and his symptom, such as numbness in both leg and feet, which had been severe, deteriorated. he underwent a magnetic resonance imaging (mri) scan of the lower back, and the intervertebral disc space between l5 and s1 was found to be narrowed and a herniated disc was manifested. thus, he decided to undergo surgery to insert artificial cartilage between l5 and s1. after surgery, the numbness in both legs and feet and the lower back pain were decreasing. during his admission period from october 10 to october 30, he asked if sd could be treated with korean medicine. after receiving our response, he decided to undergo 20 days of treatments without any kinds of herbal medicines and western drugs for sd. he completed the international index for erectile dysfunction questionnaires (iief, appendix) before and after treatment. firstly, gwanwon (cv4) and hoeeum (cv1) were used at doses of 0.1 cc and 0.2 cc, respectively, as well as sinsu (bl23) and gihaesu (bl24) at a dose of 0.1 cc at each site bilaterally. the pharmacopuncture treatment using these 4 points was conducted for 10 days. after that procedure, cv4 and cv1 were selected to maintain the sexual function effect, and the sbv pharmacopuncture was administered at doses of 0.1 cc and 0.2 cc, respectively, every other day for 10 days (fig 1). to evaluate the sexual function, we had the patient complete the iief questionnaire before and after treatment. in this study, no medical diagnostic devices were used to measure erectile dysfunction. sexual dysfunction involves several factors concerning mental satisfaction, so although completing and interpreting the results of a questionnaire are easy, no absolute and discrete values exist for individuals with and without sd. in a study, the iief questionnaire was tested in 111 men with sexual dysfunction and 109 age - matched normal volunteers. therefore, mean scores for controls (normal volunteers) and patients could be obtained. in this study, those mean scores were adopted and the scores for this case, both pre - treatment and post - treatment, and the control s scores and the patient s scores are presented in (fig 2). firstly, gwanwon (cv4) and hoeeum (cv1) were used at doses of 0.1 cc and 0.2 cc, respectively, as well as sinsu (bl23) and gihaesu (bl24) at a dose of 0.1 cc at each site bilaterally. the pharmacopuncture treatment using these 4 points were selected to maintain the sexual function effect, and the sbv pharmacopuncture was administered at doses of 0.1 cc and 0.2 cc, respectively, every other day for 10 days (fig 1). to evaluate the sexual function, we had the patient complete the iief questionnaire before and after treatment. in this study, no medical diagnostic devices were used to measure erectile dysfunction. sexual dysfunction involves several factors concerning mental satisfaction, so although completing and interpreting the results of a questionnaire are easy, no absolute and discrete values exist for individuals with and without sd. in a study, the iief questionnaire was tested in 111 men with sexual dysfunction and 109 age - matched normal volunteers. therefore, mean scores for controls (normal volunteers) and patients could be obtained. in this study, those mean scores were adopted and the scores for this case, both pre - treatment and post - treatment, and the control s scores and the patient s scores are presented in (fig 2). in this study, four acupuncture points were used, cv4, cv1, bl23 and bl24. cv4 is the front collecting point (mu point) of the small intestine and represents the intersection of the interior branches of the three yin channels of the foot. it can explain the broad effect on gynecological syndromes and disorders of the urogenital tract. also, it can play an important role in tonifying in cases of emotional and physical exhaustion. in traditional chinese medicine (tcm), it can nourish blood and yin, warm the uterus and lower warmer, invigorate kidney, yang and original qi (yuan qi), and expel dampness and cold from the lower warmer. cv1 is the beginning point of the governing vessel, the penetrating vessel and the conception vessel. thus, its effect lies in difficult urination and defecation, enuresis and impotence, pain in the penis, sweating of genitals, etc. bl23 is the back shu point of the kidney, so its indication lies in strengthening the renal function and circulation, and its point is used for all chronic diseases including disorders of the urogenital tract bl24 is one of the back shu points, and its action strengthens the lower back, regulates menstruation, and invigorates blood ; especially, it is useful for lower backache and stiffness of the lower back. the iief questionnaire is composed of 15 questions, and it is a useful tool in a clinical setting. it is a validated, multidimensional, self - reporting questionnaire and can be used to evaluate erectile function and treatment outcomes. the 15 questions can be classified into 5 categories : erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction. for example question numbers 1, 2, 3, 4, 5 and 15 can be categorized as erectile function. the perfect score differs according to the category, being 30 for erectile function, 10 for orgasmic function, 10 for sexual desire, 15 for satisfaction with intercourse, and 10 for overall satisfaction. in this case study, the patient s scores in each category were similar to those of the control group, except for sexual desire, where the patient s scores were very low. after treatment, the results showed improved erectile function, sexual desire, satisfaction with intercourse, and overall satisfaction. based on the patient s subjective self - evaluation, he also showed improvements in the duration of erection, hardness (vascularity) of the penis, and shortening of recovery period (re - action), his lower back pain decreased, the flow of urine when urinating was not interrupted, and generally he felt more confident in his life. although such sign as eye contact, brightness of eyes, volume of his voice, etc. are subjective, in this circumstance, a personal problem, observing such features may be helpful. this study has limitations in that the result of 1 case can not be generalized because of loss of control and insufficient number of subjects. besides the iief questionnaire, no other signs of improvement, such as pulse diagnosis, digital thermal imaging test, etc. nevertheless, this study could be regarded as helpful to broaden the scope for using sbv pharmacopuncture to treat urogenital diseases. in the future, additional systematic research or randomized clinical trials in this area will be needed to find the ways to treat sexual problems using pharmacopuncture and korean medicine treatments. | sexual dysfunction (sd) is a health problem which occurs during any phase of the sexual response cycle that keeps the individual or couple from experiencing satisfaction from the sexual activity. sd covers a wide variety of symptoms like in men, erectile dysfunction and premature or delayed ejaculation, in women, spasms of the vagina and pain with sexual intercourse, in both sexes, sexual desire and response. and pharmacopuncture, i.e. injection of subclinical doses of drugs, mostly herb medicine, in acupoints, has been adopted with successful results. this case report showed the effect of bee venom on sd. a 51-year - old male patient with sd, who had a past history of taking western medication to treat his sd and who had previously undergone surgery on his lower back due to a herniated disc, received treatments using pharmacopuncture of sweet bee venom (sbv) at gwanwon (cv4), hoeeum (cv1), sinsu (bl23), and gihaesu (bl24) for 20 days. objectively, the patient showed improvement on most items on the international index for erectile dysfunction (iief) like 28 to 29 out of perfect score 30 for erectile function, 10 to 10 out of perfect score 10 for orgasmic function, 6 to 8 out of perfect score 10 for sexual desire, 10 to 13 out of perfect score 15 for satisfaction with intercourse, and 6 to 8 out of perfect score 10 for overall satisfaction ; subjectively, his words, the tone of his voice and the look of confidence in his eyes all indicated improvement. among the variety of effects of sbv pharmacopuncture, urogenital problems such as sd may be health problems that pharmacopuncture can treat effectively. |
abuse of anabolic - androgenic steroids (aas) by the members of fitness centers and others has reached alarming dimensions. today, it is estimated that one to three million people has abused aas in the united states (1 - 3). they induce the protein synthesis in cellular tissues, which results in the buildup of cellular generations, especially in muscles, and in return can increase the strength and body weight in the athletes (1, 4). elevation of blood pressure, depression of serum high - density lipoprotein (hdl)-cholesterol levels and altering fasting blood sugar following the consumption of aas drugs are reported to increase the risk of cardiovascular diseases (1, 5, 6). consumption of high doses of aas may also cause liver damage by steroids metabolites (1, 7). reduced sexual function and temporary infertility can occur in males as well (8, 9). in addition, it is reported that skin diseases like acne vulgaris and folliculitis are more common in aas users (1 - 3, 10). these aas increase the activation of sebaceous glands and consequently cholesterol and free fatty acids of the skin surface lipids which in turn may provide a better condition for colonization of some lipophilic bacteria such as propionibacterium acnes and staphylococcus aureus (10 - 12). moreover, secretion of lipase by these bacteria, known to be resistant to antimicrobial activities of the fatty acids, provides a suitable environment for colonization in sebaceous follicles which in turn may present as sebaceous follicles comedones and inflamed lesions such as papules, pustules, and cysts (13). the effect of these supplements on the skin microbial flora is not clearly determined. the current study aimed to investigate the colonization of some bacterial flora among the male bodybuilders both in aas and non - aas users. male bodybuilders aas non - users and 46 non - athlete students, with similar gender and age range, were selected as the control group. the average and median ages of the bodybuilders were 24.7 and 24 years, respectively. all the participants completed a questionnaire including bathing habits, using aas and other supplements, administration of antimicrobial drugs for at least four weeks, and general medical conditions. all the participants willingly provided written informed consent approved by the ethics committee of shiraz university of medical sciences. specimens were obtained from the skin surface by swabbing 1 cm of the back and chest areas by two wet swabs. those received systemic or topical antibiotic drugs during the month before sampling were excluded from the study. the swab was directly spread on tryptone soy agar (merck, germany) supplemented with 5% v / v defibrinated sheep blood under an anaerobic condition at 37c to isolate p. acnes and under aerobic condition for s. aureus species. the isolated strains of s. aureus were identified by standard methods including colony morphology, gram stain, catalase test, mannitol fermentation and coagulase test on aerobic overnight cultured samples. to isolate p. acnes, following seven days of anaerobic incubation, the plates were examined to detect bacterial colonies that were not present in the aerobic conditions. p. acnes were identified by lack of growth in aero tolerance plate, colony morphology, gram stain, and indole test (s+) (14). the number of isolated bacteria from each swab was counted and recorded for each bacterium per anaerobic and aerobic plates. the quantity of both isolated p. acnes and s. aureus from each sample site was clustered into four groups (0, 1 - 9, 10 - 49, > 50) based on the corresponding colony forming unit / cm2 (cfu / cm2). the 2 test was used to examine the bacterial colonization at the examined sites between the aas users and the others. it is mean (average) and median which are 24.75.1 and 24 years, respectively. lesional skins were higher in the athletes than in the non - athlete controls and this difference was statistically significant (p 0.05). of the aas - user athletes, 40 (56.3%) reported to take bath 2 - 5 times per week and the rest (n = 31, 43.7%) took bath daily or more. similarly, 12 (52.2%) and 11 (47.8%) of aas non - user athletes took bath 2 - 5 times per week and on daily basis, respectively. no significant difference in the number of taking bath per week was found between the above mentioned groups of athletes (aas - user vs. aas non - user athletes). the anaerobic cultures of 24.2% of the athletes were positive ; among them 94.1% were from the aas users whereas the aerobic cultures of the skin yielded positive results in 92.6% of the athletes among whom 75.9% were aas users. actual data based on colony counts and in the athletes and control groups are shown in table 3. there were statistically significant differences regarding bacterial flora including s. aureus and p. acnes between athletic (aas - user and aas non - user) and non - athletic groups. in addition, there was a significant difference in distribution of p. acnes was found between bodybuilders who used aas and those who did not (p 0.05). abbreviations : aas (+) : anabolic - androgenic steroids consumer, athl : athletes, aas(-) : anabolic - androgenic steroids non - users, non - athl : non- athletes, n : number, % : percent. abbreviations : aas (+) : anabolic - androgenic steroids consumer, athl : athletes, aas (-) : anabolic - androgenic steroids non - users, non - athl : non - athletics, n : number, % : percent. between aas (+) athl and non - athl. aas (+) : anabolic - androgenic steroids consumer, athl : athletes, aas (-) : anabolic - androgenic steroids non - users, non - athl : non- athletes, n : number, % : percent. utilizing performance enhancing drugs has dramatically increased among the young athletes to rebuild body mass and strength, increase delivery of oxygen to muscles and treat pain without any concern about their serious side effects. on the other hand, all adverse effects of these drugs are not clearly investigated (1, 2, 15). the occurrence of the cutaneous striae, oily skin, alopecia and male patter hair loss is commonly reported as a result of aas abuse in athletes (10, 16). in addition, the frequency of acnes in aas users was 40%-54% (2, 17, 18). the current study reported statistically significant higher skin lesions in aas abusers compared to the others. previously, it was indicated that methyl testosterone and its metabolites may enhance the bacterial proliferation and their enzymatic activities (19). in another study, kiraly showed that mild acne induced following eight weeks of self - administration of high dose testosterone and anabolic steroids (16). kiraly also found that high doses of testosterone and aas may increase the skin surface lipids which in turn may provide a suitable condition for the growth of p. acnes (16). on the other hand, supra - physiologic doses of aas may or can affect the immune system (20, 21). several common aas alter the immune reaction by adversely influencing lymphocyte differentiation and proliferation, antibody production, natural killer cytotoxic activity and the production of certain cytokines, and thereby enhancing bacterial proliferation (20, 21). in the present study, skin cultures yielded positive results for p. acnes in 45% of the aas - user bodybuilders which was about four times as much as those of non - aas user bodybuilders and 18 times as much as the controls. these results were in agreement with those of the study by kiraly who showed that the population of p. acnes increased significantly in the self - administrated aas young individuals following eight weeks of using aas (16). in addition, the current study also found more frequent positive cultures (odds ratio = 3.8) in the non - aas user bodybuilders in comparison with those of the non - athletic control group ; this might be caused by higher rates of bacterial transmission among athletes through direct skin contact with exercise instruments in the gym. staphylococcus aureus is the most common cause of primary and secondary human skin infections (22, 23), though it is not considered as an inhabitant normal flora of the skin. it is commonly found on the skin of the normal population with frequency of 18%-40% (24, 25). the present study found a higher rate of s. aureus positive cultures in the athletes compared to the controls. however, there was no statistically significant difference in the culture results between the two studied athletic groups ; it may suggest that using aas has no role in s. aureus colonization. it was previously shown that environmental sources such as shared equipment and towels may play a role in community acquired s. aureus in the athletes (26, 27). the higher colonization of s. aureus in the athletes in comparison with the controls may be caused by the bacterial transient skin flora passing through the exposure of bare skin to the exercise instruments. a significant association was previously reported by singh. between high colonization of s. aureus and the possibility of the skin infection (28). therefore, as shown previously (28, 29), the high number of colonies (> 50) isolated in about one third of the bodybuilders may predispose them to skin infections. to investigate the side effect of aas further, studies should include other sports and both sexes. in addition, expanding the investigation to a larger cohort could provide more valuable information about the impact of aas on the bacterial skin colonization. | background : anabolic - androgenic steroids (aas) abuse by the athletes has dramatically increased during the recent decades. these substances might increase the skin lipids and enhance the cutaneous microbial proliferation.objectives:the current study aimed to investigate the potential side effects of aas on the bacterial microflora colonization of the bodybuilders ` skin.patients and methods : the skin samples of 94 male bodybuilders (71 aas users, 23 non - aas users) and 46 subjects of the control group, with similar gender and age, were cultured and incubated in both aerobic condition to isolate staphylococcus aureus and anaerobic condition for propionibacterium acnes. the isolated bacteria were identified by standard microbiological techniques.results:the skin lesions were more frequent in the body builders than the controls. moreover, statistically significant differences were also observed in skin lesions among the aas users and the non - aas user athletes. the prevalence of s. aureus and p. acnes in the athletes was higher than that of the control group. in addition, there was a significant difference in distribution of p. acnes between the bodybuilders who used aas and those who did not.conclusions:a higher number of bacterial flora was found in the bodybuilders particularly those using aas in comparison to the controls, which might be due to the influence of these aas on the skin microflora and transmission of the bacteria through the direct contact of the naked skin with the exercise instruments. |
his planned chemotherapy for myelodysplastic syndrome had been stopped a month before due to fungal infection of the orbit. the initial absolute neutrophil count was only 130/mm, and antibiotic therapy was initiated under the possibility of pneumonia or aggravation of orbital infection. even after 7 days of antibiotic therapy, the fever persisted and no evidence of infection was found. we performed transthoracic echocardiography under suspicion of infective endocarditis ; a 13 mm echogenic mass was found on the atrial side of the tricuspid valve (fig. based on the clinical symptoms and the echocardiographic findings, the patient was highly suspected of having infective endocarditis of the tricuspid valve. he was scheduled for emergency surgical removal due to the possibility of fungal endocarditis and the poor clinical course of infective endocarditis in immunocompromised patients. with a cardiopulmonary bypass, the right atrium was opened after aortic cross - clamping and cardioplegic arrest. on the exploration, a solitary polypoid gelatinous mass 1316 mm in size infiltrating the septal leaflet of the tricuspid valve 2). although the tumor had a stalk, simple resection without making a defect in the septal leaflet appeared to be impossible, because the leaflet was too thin. therefore, the mass was excised with part of the septal leaflet of the tricuspid valve using the quadrangular resection technique, followed by reconstruction with autologous pericardium. after successful weaning from the cardiopulmonary bypass, intraoperative transesophageal echocardiography was performed, showing no residual tumors. papillary fibroelastoma was pathologically confirmed, and no evidence of infective endocarditis was found (fig. follow - up transthoracic echocardiography showed no residual or recurrent tumor, with uneventful postoperative recovery. primary cardiac tumor is very rare, and its frequency is approximately 0.02% according to the data from 22 autopsy cases. cardiac papillary fibroelastoma is the third most common benign primary cardiac neoplasm and the most common cardiac valvular tumor. grossly, cardiac papillary fibroelastoma is a gelatinous mass with multiple narrow papillary fronds, and it attaches to the endocardium via a short pedicle. when the tumor is put in saline immediately after excision, it typically has a sea anemone - like appearance. the microscopic appearance is an avascular finger - like process with a core of elastin surrounded by collagen, which is covered by a single layer of endothelium. the size of a cardiac papillary fibroelastoma varies from 2 to 70 mm, but the majority of tumors are approximately 10 mm in diameter. the tumor is usually solitary, but rare cases of multiple cardiac papillary fibroelastoma have been reported. most of the tumors are located on the valvular surface, especially near or on the aortic valve (44%) and mitral valve (35%). less frequently, the tumor infiltrates the pulmonary valve (8%) or the leaflets of the tricuspid valve (15%). the clinical presentation of a cardiac papillary fibroelastoma varies from no symptoms to severe thromboembolic complications, including transient ischemic attack, stroke, and myocardial infarction. other complications include pulmonary embolism, congestive heart failure, near syncope, and sudden death. cardiac papillary fibroelastoma occasionally manifests with fever, which abates after removal of the tumor. our patient with cardiac papillary fibroelastoma had a fever, which did not subside even after several days of antibiotic therapy. however, after surgical removal of the tumor, the fever disappeared during the hospital stay. occasionally, a small cardiac papillary fibroelastoma may not be detected with transthoracic echocardiography ; therefore, transesophageal echocardiography is required to further assess such a small tumor. computed tomography and magnetic resonance imaging are also helpful in detecting cardiac papillary fibroelastoma, but their diagnostic accuracy is relatively low. the mobility and location of the papillary fibroelastoma that has developed on the valvular surface can be misdiagnosed as infective vegetation. in comparison with cardiac papillary fibroelastoma, infective vegetation is usually associated with clinical signs of endocarditis and valvular destruction, and may resolve or change over a short period after treatment. it is obvious that surgical excision is necessary in symptomatic patients with intracardiac tumors proven by echocardiography, regardless of the type and the location of tumors. however, when the tumor is a left - sided lesion, surgical excision is recommended due to high - risk thromboembolic events. controversially, right - sided lesions are observed and surgically removed only in case they become symptomatic. the risk of cardiac surgery in patients with hematologic malignancies remains to be established. fecher. demonstrated, in a study of 24 patients with hematologic malignancies undergoing cardiac surgery, that there was 1 in - hospital patient death (4.1%), 12 patients (50%) with a minor or major complication, and 7 patients requiring reoperations within 30 days due to bleeding, infection, and other clinical conditions. chan. reported, in a study of 26 patients with hematologic malignancies, that although there was no significant difference in mortality between patients with and without hematologic malignancies, there were significantly higher rates of transfusion, pneumonia, and sepsis in patients with hematologic malignancies than in patients without. the patient in this study improved after removal of the cardiac papillary fibroelastoma without any complications, and he is still alive at the 6-month follow - up. | we report a 72-year - old male with known myelodysplastic syndrome who presented to the emergency department with a 7-day history of fever and dyspnea. echocardiography revealed a round echogenic mass 1316 mm in size attached to the atrial side of the tricuspid valve. considering the high risk of infective endocarditis in the patient with a low absolute neutrophil count (130/mm3), emergency surgery was performed. intraoperatively, a single gelatinous neoplasm was resected, and subsequent reconstruction of the involved leaflet was accomplished using autologous pericardium. the tumor was pathologically confirmed as papillary fibroelastoma with no evidence of infective endocarditis. papillary fibroelastoma is a rare cardiac neoplasm that occurs in either the mitral or aortic valves. interestingly, a few cases of tricuspid valve papillary fibroelastoma have been reported so far. similar echocardiographic findings between vegetation and tricuspid valve neoplasm make it difficult to distinguish these two disease entities. |
a stroke is often accompanied by secondary complications such as nutritional and metabolic disorders, endocrine dysfunction, mental problems, and cardiopulmonary disorders owing to neurological system and musculoskeletal system deficits associated with brain damage1. among these complications, pulmonary disorders are more closely related to life and cause problems with the ability to adjust respiration, swallowing, as well as, language2. non - use of the paretic side muscles, and difficulty with movement, accompanied by direct restrictive pulmonary impairments, trigger a secondary reduction in cardiopulmonary function, and the asymmetric trunk induces inefficient energy use related to gait, resulting in a decrease in exercise endurance3. patients with hemiplegia caused by stroke undergo abnormal movement of the trunk and, in particular, abnormal movement in posture and motor control. in addition, damage to the abdominal area and chest wall, directly and indirectly decrease mobility of the respiratory muscles, and weakens their strength and endurance, affecting the respiratory cycle4, 5. during aerobic exercise, which demands endurance, when such patients return to their local community, they may have difficulty with activities of daily living, as well as, gait7. general rehabilitation programs for stroke patients, that only aim towards functional recovery of the body, are not sufficient to enhance cardiopulmonary system function8. as such, rehabilitation programs that integrate interventions related to respiration could be more effective in stroke patients for improving functional activities such as gait9. chest resistance exercises promote the alignment of respiratory muscles with respiratory rhythms by providing resistance to the sternal and costal areas to resolve the respiratory problem itself10. conversely, a chest expansion exercise is a full - body exercise technique that combines deep breathing with active movements of the trunk and limbs. this exercise is an intervention method more specific to the musculoskeletal system as it moderates inspiration and expiration rates, improves mobility of the intercostal space, relaxes the stiff connective tissue, and relaxes soft tissues such as the pectoralis major, intercostal, and quadratus lumborum muscles11. a previous study in stroke patients12 noted that chest resistance exercises and diaphragmatic resistance exercises, by way of the proprioceptive neuromuscular facilitation (pnf) method, improved the subjects pulmonary function, leading to expansion of the pulmonary tissue, improvements in thorax movement, strengthening of the respiratory muscles, and an enhancement in endurance. britto.4 applied inspiratory muscle training to chronic stroke patients and reported strengthening of the inspiratory muscles, as well as, an improvement in endurance within a short time period. in another study by leelarungrayub.13, in which chronic obstructive pulmonary disease patients conducted chest expansion exercises, there was significant improvement in pulmonary function, dyspnea, and the degree of chest expansion. moreover, when stroke patients performed chest resistance exercises based on the pnf method, there was significant improvement in their gait ability, degree of chest expansion, and forced expiratory volume in 1 second (fev1)14. indeed, various previous studies in healthy individuals, as well as patients with obstructive pulmonary disease, spinal cord injuries, cerebral palsy, and neuromuscular disease have been performed ; however, studies evaluating respiratory function in stroke patients following chest resistance and chest expansion exercises, and examining the relation of trunk control ability with respiratory function, are lacking. accordingly, this study aims to examine the efficiency of chest resistance and chest expansion exercises for improving respiratory function and trunk control ability in patients with hemiplegia caused by a stroke, and to compare the effects of these interventions. study subjects was stroke patients who had suffered a stroke and were hospitalized and treated at the n hospital located in daegu city, korea. all subject was randomly allocated to a chest resistance exercise group (creg, n = 20) or chest expansion exercise group (ceeg, n = 20). the criteria for study subject selection included those who were chronic stroke patients whereby the onset of stroke occurred at least six months prior ; those whose korea mini mental state examination score was 24 points or higher ; those who had no special pulmonary disease before the onset of stroke ; those who had no innate deformation of the thorax or rib fracture ; and those who were able to sit independently. this study was approved by the daegu university institutional review board and all study - related procedures were conducted in accordance with the ethical standards of the declaration of helsinki. all subjects understood the purpose of the study and written informed consent was received from all subjects prior to their participation. the patients assumed a supine and side - lying position while undergoing chest resistance exercise patterns and the diaphragmatic palpation technique of the pnf on the costal area. briefly, the therapist places both hands on the costa of the patient, with the fingers placed diagonally along the costal line. pressure is then applied from the costal area, in a caudal and medial direction, in line with the patient s respiratory rhythm so that the patient can sufficiently breathe out during expiration, while in supine position. the therapist diagonally applies pressure in a caudal and medial direction along the costal line, drawing an arc in line with the patient s respiratory rhythm on side - lying position. the diaphragm is then palpated by pushing it superiorly and laterally with the thumb or other finger from below the thorax. the therapist gives resistance to the inferior movement of the contracting diaphragm. in order to provide indirect palpation, the therapist places both hands on the abdominal area and has the patient inhale while pushing diaphragm superiorly with smooth pressure on supine position. in this interventional method, the therapist pushes the patient s shoulder area in an anterior - inferior direction and pulls the pelvic area in a posterior - superior direction, in line with the patient s respiratory cycle. during inspiration, the therapist pulls the shoulder area in a posterior - superior direction and pushes the pelvic area in an anterior - inferior direction so that the thorax can be sufficiently expanded during inspiration while in the side - lying position., the patient s trunk is rotated and flexed in the direction of the non - paretic side and the paretic side elbow is pushed in an anterior - inferior direction toward the non - paretic side knee. during inspiration, the trunk is maximally rotated in the paretic side direction such that the elbow is in a posterior - superior direction to sufficiently expand the paretic side thorax while the patients is in a seated position. the chest stretching exercise was also conducted with the patient in a seated position. during expiration, the therapist pushes together the bilateral elbows anteriorly and flexes the upper part of the patient s trunk. during inspiration, the patient spreads the bilateral elbows externally and extends the trunk to expand the thorax. all subjects who participated in the study conducted an ex - ante evaluation before initiating the exercise program, and were re - evaluated eight weeks later. the subjects respiratory function was assessed based on forced volume vital capacity (fvc), and fev1, and their trunk control ability was measured using the trunk impairment scale (tis). a paired t - test was carried out to examine group differences, before and after the experiment, and an independent t - test was conducted to evaluate differences between the two groups. in this interventional method, the therapist pushes the patient s shoulder area in an anterior - inferior direction and pulls the pelvic area in a posterior - superior direction, in line with the patient s respiratory cycle. during inspiration, the therapist pulls the shoulder area in a posterior - superior direction and pushes the pelvic area in an anterior - inferior direction so that the thorax can be sufficiently expanded during inspiration while in the side - lying position. the patient s also underwent trunk rotation exercises. during expiration, the patient s trunk is rotated and flexed in the direction of the non - paretic side and the paretic side elbow is pushed in an anterior - inferior direction toward the non - paretic side knee. during inspiration, the trunk is maximally rotated in the paretic side direction such that the elbow is in a posterior - superior direction to sufficiently expand the paretic side thorax while the patients is in a seated position. the chest stretching exercise was also conducted with the patient in a seated position. during expiration, the therapist pushes together the bilateral elbows anteriorly and flexes the upper part of the patient s trunk. during inspiration, the patient spreads the bilateral elbows externally and extends the trunk to expand the thorax. all subjects who participated in the study conducted an ex - ante evaluation before initiating the exercise program, and were re - evaluated eight weeks later. the subjects respiratory function was assessed based on forced volume vital capacity (fvc), and fev1, and their trunk control ability was measured using the trunk impairment scale (tis). statistical processing of the data was conducted using spss ver. 12.0, and descriptive statistics was used to analyze the subjects general characteristics. a paired t - test was carried out to examine group differences, before and after the experiment, and an independent t - test was conducted to evaluate differences between the two groups. table 1table 1.general characteristics (mean sd)cregceeggender (male / female)12 / 811 / 9paretic side (right / left)9 / 119 / 11diagnosis (infarction / hemorrhage)11 / 99 / 11age55.50 11.4358.30 11.10time since stroke4.70 1.693.95 1.63mmse - k28.25 1.8327.35 1.81creg : chest resistance exercise group, ceeg : chest expansion exercise group, mmse - k : mini mental status examination - korea version, p > 0.05. shows the general characteristics of the study subjects. there were no significant differences in any of the characteristics between the creg and ceeg groups (p > 0.05). creg : chest resistance exercise group, ceeg : chest expansion exercise group, mmse - k : mini mental status examination - korea version, p > 0.05. table 2table 2.comparison of creg and ceeg respiratory function and trunk control ability (mean sd)cregceegpretestposttestpretestposttestfvc (l)2.13 0.902.68 1.21 1.89 1.002.62 10.93fev1 (l)1.65 0.702.03 0.83 1.52 0.732.18 0.69fev1/fvc (%) 82.52 22.1381.42 18.7282.19 16.4386.88 10.68tis11.56 0.8814.13 0.92 11.49 1.1412.17 1.17significant difference from the pretest at 0.05, table 2). fev1 : forced expiratory volume at one second, tis : trunk impairment scale between - group comparisons, before and after the intervention, showed no significant differences between the two groups in fvc, fev1, and fev1/fvc (p > 0.05). however, tis was more significantly improved in the creg compared to the ceeg after the intervention (p < 0.05, table 2). this study compared chest resistance exercises and chest expansion exercises applied to patients with stroke - related hemiplegia by closely examining the efficiency of the interventions in improving respiratory function and trunk control ability. to examine respiratory function of the subjects, this study measured fvc, fev1, and fev1/fvc. according to the results of this study, both the creg and the ceeg groups showed significant improvements in respiratory function and trunk control ability. in a previous study, sutbeyaz.15 classified stroke patients in a sub - acute state into an inspiratory muscle training group, a respiratory retraining group, and a control group, and applied interventions six times per week for six weeks to compare pulmonary function between groups. the results showed that fvc and fev1 of the inspiratory muscle training group significantly increased. similarly, kim jae - hyeon12 applied chest mobility exercises, chest resistance exercises using the pnf method, and respiration exercises using diaphragmatic respiration exercise in stroke patients for four weeks, and their vital capacity, fvc, fev1, and maximal voluntary ventilation significantly changed. in another study by mueller.16, respiration exercises in spinal cord injury patients resulted in a significant increase in fev1/fvc and fev1. jeong ju - hyeon and kim nan - su17 reported that following breathing exercises for six weeks using resistive inspiratory muscle training, the subjects fev1 and maximal expiratory pressure significantly improved but fvc and fev1/fvc did not significantly increase. britto.4 applied respiration exercises, using a respiratory resistance instrument in stroke patients, and reported that there were significant changes in the maximal inspiratory pressure and inspiratory muscle endurance. in line with the results of the previous studies mentioned above, the subjects fvc and fev1, in the present study, significantly improved after undergoing chest resistance exercises for eight weeks. this finding is not surprising given that the provision of resistance would be expected to ameliorate the strength and endurance of the respiratory muscles, with effective improvements in the subjects respiratory functions. kim sang - hoe18 reported that a combination of lumbar stabilization exercises and trunk stretching significantly improved fvc. lima.19 applied a neck and trunk muscle mobilization technique in healthy subjects and found that the fev1 and peak expiratory flow rate were significantly improved. seo gyo - cheol.14 applied chest expansion exercises and resistance exercises to subjects for four weeks and reported that there were significant changes in fvc, fev1, and maximal expiratory flow, but not in fev1/fvc. similarly, in the present study, the subjects fvc and fev1 significantly improved after the chest expansion exercises. this result supports burianova s opinion20 that chest expansion exercises achieve appropriate contraction of the respiratory muscles and enhance ventilation by promoting muscle activity. jandt.21 compared the association between trunk control, respiratory muscle strength, and pulmonary function in stroke patients and noted that a consistent and statistically significant correlation was found between tis and peak expiratory flow and between tis and maximum expiratory pressure. in a study by kim min - hwan22 where stroke patients received expiratory muscle training five times per week for six weeks, the experimental group showed significant improvements in trunk control ability compared to the control group. gu tae - wu23 observed that a combination of thoracic mobilization and respiration exercises resulted in significant enhancements in the subjects trunk control ability. in the present study, which examined the subjects trunk control ability after the application of chest resistance and chest expansion exercises, the tis significantly improved in both groups with more significant improvements in the creg than in the ceeg. this is likely due to improvements in respiratory muscle function following the application of each exercise program which could affect trunk control ability. more significant improvements observed in the creg group could be attributed to enhancements in respiratory muscle strength and endurance with chest resistance exercises, which more greatly affect trunk stability in comparison to chest expansion exercises. a limitation of the present study is that it is difficult to generalize the current observations, as the number of subjects is small. as such, further long - term studies on a larger subset of stroke patients, and with regular follow - up intervals to ascertain nevertheless, the results of the present study show that both chest resistance exercises and chest expansion exercises were effective in improving respiratory function and trunk control ability in hemiplegic stroke patients, however chest resistance exercises were more effective than chest expansion exercises. thus, chest resistance exercises and chest expansion exercises may be suitable and effective therapeutic intervention methods to improve respiratory function and trunk control ability in stroke patients. | [purpose ] the purpose of this study was to examine the efficiency of chest resistance and chest expansion exercises for improving respiratory function and trunk control ability in patients with stroke. [subjects ] forty patients with stroke were randomly allocated into a chest resistance exercise group (creg, n = 20) and a chest expansion exercise group (ceeg, n = 20). [methods ] creg patients underwent chest resistance exercises, and diaphragmatic resistance exercises by way of the proprioceptive neuromuscular facilitation. ceeg patients underwent respiratory exercises with chest expansion in various positions. both groups received 30 minutes of training per day, five times per week, for eight weeks. [results ] both the cerg and ceeg groups showed significant changes in fvc, fev1, and tis after the intervention. tis was significantly increased in the creg compared to the ceeg after the intervention. [conclusion ] both chest resistance and chest expansion exercises were effective for improving respiratory function and trunk control ability in stroke patients ; however, chest resistance exercise is more efficient for increasing trunk control ability. |
congenital anomalies of the urachal remnant range from a diverticulum to a sinus or a patent urachal remnant extended from the bladder up to the umbilical fossa. the latter anomaly often induces inflammation along the tract and/or urine leakage from the umbilicus. the principal treatment of an urachal remnant is the complete resection of the whole tract. this requires a long midline skin incision in the lower abdomen, which inevitably causes a major cosmetic disadvantage of a conspicuous scar formation. to alleviate this drawback, laparoscopic excision of the urachal remnant was first demonstrated in 1992 by neufung., and since then several trials of laparoscopic surgery to correct the urachal anomaly have been reported,,,,,,,,. however, the techniques, including port placement arrangements and division and suture of the bladder, have not yet been standardized. furthermore, the method of closing the bladder opening after resection of the remnant tract is still controversial. some authors maintain the usefulness of a stapler under laparoscopic view to close the bladder apex, a technique which contradicts the opinion of urologists who argue that absorbable sutures should be used to minimize the risk of urolithiasis. here, we review our experience of excising the urachal remnant using the abdominal wall - lift laparoscopy. this method provides for the relatively free use of conventional instruments and techniques and eliminates pneumoperitoneum- or co2-related complications. for optimal incision and closure of the bladder apex a 21-year - old previously healthy woman was referred to our hospital with complaints of periumbilical discharge and pain on urination. she had a lean physique with body mass index of 17 [42.6 kg/(1.58 m) ]. a physical examination found purulent discharge from the bottom of the umbilicus and a reddish tinge to the surrounding skin. abdominal computed tomography(ct) and magnetic resonance imaging(mri) revealed an abscess in the umbilical region that was connected to the bladder via a long band, in part via a long tube - like structure(fig. after treatment with antibiotics and anti - inflammatory drugs, an elective laparoscopic surgery was performed. under general anesthesia, the patient was placed in a leg - open position and a transurethral foley catheter was inserted. the surgeon and camera surgeon stood on the left side of the patient with the monitor in a caudal position relative to the patient. through a 15 mm infra - umbilical incision, the subcutaneous tissue and the anterior layer of the rectus fascia were dissected in a t - shape. the urachal remnant was then continuously dissected distally as far as possible in the preperitoneal space. a small - sized lapprotector (hakko, nagano, tokyo) was inserted through the umbilical incision into the preperitoneal space. for the abdominal wall - lift, two wires were placed subcutaneously and pulled upward, 2 cm below the umbilicus and halfway between the umbilicus and the pubis, respectively (fig. 2). a rigid, straight - viewing laparoscope was inserted via the lapprotector. the urachal remnant was dissected toward the bladder mainly with a bipolar sealing device (ligasure)(covidien, mn). the dissection was mostly performed in the preperitoneal space and sometimes in the abdominal cavity. a 6 cm pfannenstiel incision was added 2 cm above the pubis to get access to the conjunction of the urachal remnant to the bladder. after the bladder was filled with 300 ml of saline through the foley catheter, a bladder cuff including the urachal insertion was excised along with the whole urachal sinus. the opening at the bladder apex was closed with absorbable sutures (4 - 0 vicryl)(johnson & johnson, nj) under direct vision. the peritoneal defects were closed with several running sutures under a laparoscopic view from the umbilical incision (fig. 3). seprafilm (kaken pharmaceutical, tokyo, japan) was placed under the sutured peritoneum to prevent adhesion. the patient had no complaints of symptoms 18 months postoperatively and was satisfied with the cosmetic results. the umbilical - incision scar was hardly visible and the pfannenstiel incision was concealed by regrowth of pubic hair. under general anesthesia, the patient was placed in a leg - open position and a transurethral foley catheter was inserted. the surgeon and camera surgeon stood on the left side of the patient with the monitor in a caudal position relative to the patient. through a 15 mm infra - umbilical incision, the subcutaneous tissue and the anterior layer of the rectus fascia were dissected in a t - shape. the urachal remnant was then continuously dissected distally as far as possible in the preperitoneal space. a small - sized lapprotector (hakko, nagano, tokyo) was inserted through the umbilical incision into the preperitoneal space. for the abdominal wall - lift, two wires were placed subcutaneously and pulled upward, 2 cm below the umbilicus and halfway between the umbilicus and the pubis, respectively (fig. 2). a rigid, straight - viewing laparoscope was inserted via the lapprotector. the urachal remnant was dissected toward the bladder mainly with a bipolar sealing device (ligasure)(covidien, mn). the dissection was mostly performed in the preperitoneal space and sometimes in the abdominal cavity. a 6 cm pfannenstiel incision was added 2 cm above the pubis to get access to the conjunction of the urachal remnant to the bladder. after the bladder was filled with 300 ml of saline through the foley catheter, a bladder cuff including the urachal insertion was excised along with the whole urachal sinus. the opening at the bladder apex was closed with absorbable sutures (4 - 0 vicryl)(johnson & johnson, nj) under direct vision. the peritoneal defects were closed with several running sutures under a laparoscopic view from the umbilical incision (fig. 3). seprafilm (kaken pharmaceutical, tokyo, japan) was placed under the sutured peritoneum to prevent adhesion. the patient had no complaints of symptoms 18 months postoperatively and was satisfied with the cosmetic results. the umbilical - incision scar was hardly visible and the pfannenstiel incision was concealed by regrowth of pubic hair. the lumen near the umbilicus was covered with stratified squamous cells. inflammatory cell infiltration was mild and no abscess formation was found. the patient had no complaints of symptoms 18 months postoperatively and was satisfied with the cosmetic results. the umbilical - incision scar was hardly visible and the pfannenstiel incision was concealed by regrowth of pubic hair. the urachal remnant is a rare congenital anomaly with an incidence of 1:300,000 in infants and 1:5000 in adults. infection can occur as a common complication of the urachal remnant, and urachal carcinomas have also been reported,. until recently, excision of the urachal remnant was performed by a laparotomy with a long skin incision from the umbilicus to the suprapubic area,. after the description of a laparoscopic resection of the urachal remnant by neufang. in 1992, several more reports on laparoscopic techniques have been published,,,,,,,,. a laparoscopic resection of the urachal remnant has been suggested to be technically feasible and minimally invasive. it has also been suggested that a laparoscopic procedure provides better cosmesis, thus contributing to the quality of life of young female patients in particular. according to earlier reports, laparoscopic management of the urachal remnant seems to be safe and relatively easy, but attention should be made to the following points. first, various port placement arrangements have been proposed. before the advent of single - port laparoscopic surgery, a camera port and other trocars were placed away from the umbilicus, and a 30 oblique laparoscope was used to observe the lesion in the anterior abdominal wall. in the current case, we used the abdominal wall - lift laparoscopy to get a good view of the preperitoneal space with a camera port at the umbilicus. in this way we could insert a straight - viewing laparoscope and some additional manipulating instruments without the need for additional trocars. second, an incomplete resection of the remnant may lead to recurrent infections. in this sense, complete excision is essential although the edge of the bladder has an ill - defined border. furthermore, the technique chosen to close the bladder opening after resection of the remnant tract (stapler or absorbable sutures) is also important and has consequences for possible urolithiasis. for precise detection and division of the bladder junction followed by meticulous suturing of the bladder opening, we suggest that surgeons make an additional incision above the pubis, as described in the present case. the pfannenstiel incision that we used provides a good view of the operative field as well as an excellent cosmetic outcome. third, peritoneal defects can occur during excision of the urachal remnant even with a preperitoneal approach. but the direct sutures from the umbilical incision are easily done under a laparoscopic view with an abdominal wall - lift. the combined use of a bio - absorptive adhesion - preventive film may be of some help to prevent intestinal obstruction after surgery. in conclusion, we propose that the abdominal wall - lift technique is a promising surgical option for patients with a symptomatic urachal remnant, in terms of optimal procedures and satisfactory cosmetic results. written informed consent was obtained from the patient for publication of this case and any accompanying images. | highlightsabdominal wall - lift technique is a promising surgical option for patients with a symptomatic urachal remnant.the pfannenstiel incision provides a good view of the operative field as well as an excellent cosmetic outcome.urachal sinus excision using the abdominal wall - lift laparoscopy seems to surpass the previously reported methods in term of safety, cosmetics, and adequacy of surgical procedures. |
a harmony between the soft and hard tissues of the chin is necessary for an attracttive lower one - third and overall facial beauty. contemporary orthodontics aims to restore facial esthetics ; which is influenced by the facial hard and soft tissues. it has been reported that soft tissue profile is related to the underlying skeletal and dental structures., it has been stated that the underlying hard tissue does not necessarily influence the entire facial soft tissue. orthodontic treatment may be performed in the form of extraction or non - extraction treatment. patients with dental crowding or bimaxillary dentoalveolar protrusion usually undergo extraction of the first or second premolars for retraction and alignment of teeth. in patients with mild problems or those requiring correction of the angulation of teeth, the treatment aims to correct the dentoalveolar problems and subsequently the soft tissue profile to create a more desirable appearance. bishara, and young and smith stated that extraction of premolars had no deleterious effects on the facial profile. verma, stated that in patients with class ii division i malocclusion, the soft - tissue facial profiles of the non - extraction and extraction cases were the same except for a more retruded lower lip and a more pronounced lower labial sulcus in the latter. there are few studies on the effects of extraction and non - extraction orthodontic treatments on the soft tissue of the mandible and chin. bowman and johnston and paquette, compared extraction and non - extraction patients and reported that after treatment, extraction patients had a straighter profile than non - extraction patients. numerous studies have evaluated upper lip and lower lip changes after extraction of premolar teeth and retraction of incisors but limited studies have evaluated hard and soft tissue changes of the mandible and chin in patients after different orthodontic treatments. the aim of this study was to assess the changes in hard and soft tissue of the mandible after treatment with extraction or non - extraction orthodontic protocols. this inception cohort study with two arms was conducted on 36 class i adult patients out of which, 18 were diagnosed with class i bimaxillary protrusion based on clinical examination and cephalometric analyses ; their treatment plan consisted of extraction of all four first premolars and retraction of incisors. the remaining 18 patients comprised the non - extraction group and their treatment plan included correction of the position of incisor teeth without extraction of premolars. the patients were selected among those presenting to a private office and orthodontic department of tehran university of medical sciences. the mean age at the onset of treatment was 16.380.4 years and the mean duration of treatment was 246 months. the inclusion criteria were as follows : - female patients with class i malocclusion based on clinical and paraclinical examinations- complete health in terms of absence of craniofacial disorders- no history of trauma to the jaws- patient cooperation throughout the treatment course- patients treated with fixed straight wire appliances (0.022-inch ; mbt prescription, 3 m unitek, monrovia, ca, usa) - female patients with class i malocclusion based on clinical and paraclinical examinations - complete health in terms of absence of craniofacial disorders - no history of trauma to the jaws - patient cooperation throughout the treatment course - patients treated with fixed straight wire appliances (0.022-inch ; mbt prescription, 3 m unitek, monrovia, ca, usa) the before and after treatment cephalograms of patients with acceptable quality were manually traced. for the assessment of intra - observer reliability, all cephalograms were traced twice in the morning and in the evening with an intraclass correlation coefficient (icc) of 0.97. the inter - observer reliability was calculated and confirmed by an expert orthodontist with an icc of 0.96. the lateral cephalograms were taken in standard centers, and their magnification was taken into account. the measured cephalometric parameters are summarized in table 1, including angular measurements, the reference planes (fig. 1) and symphysis measurements (fig. cephalometric angular measurements and reference planes (1) sna (2) snpog (3) snb (4) snpog (5) impa (6) interincisal angle (7) y - axis (8) gonial angle (9) articular angle (10) saddle angle (11) angle of convexity (12) soft tissue angle of convexity symphysis measurements (1) hard tissue height of symphysis (2) hard tissue depth of symphysis (3) soft tissue height of symphysis (4) soft tissue depth of symphysis some cephalometric landmarks and parameters used in the present study repeated measures anova was used for the comparison of the two groups of extraction and non - extraction patients. the relationship between soft and hard tissue variables was studied using the pearson s correlation coefficient. the comparisons of pretreatment and post - treatment cephalometric observations of extraction and non - extraction cases are demonstrated in tables 2 and 3, respectively. the mean angular changes in b point indicated by the snb angle were relatively the same (p=0.693) in both groups of extraction (0.761.33) and non - extraction (1.012.31), and the difference between pre and post - treatment results was statistically significant (p=0.008). comparison of the pre - treatment and post - treatment values of patients with extraction treatment = significant differences (p<0.05) comparisons of the pre - treatment and post - treatment values of non - extraction patients = significant differences (p<0.05) the mean changes in the pogonion (pog) indicated by sn - pog were approximately similar (p=0.285) in the two groups of extraction (0.421.34) and non - extraction (1.172.61), and the difference between pre and post - treatment results was statistically significant (p=0.028).the mean changes in angle of convexity of soft tissue (napog) were not significantly different between extraction (1.131.40) and non - extraction (0.761.95) groups (p=0.528), and the difference after treatment was statistically significant (p=0.002). the mean symphysis depth of the soft tissue changed significantly after treatment (p=0.008) but the mean changes were not different in the extraction (0.431.22) and non - extraction (0.711.23) groups (p=0.496). the mean changes in symphysis depth in the hard tissue were statistically significant and different in the two groups (p=0.021). the mean symphysis depth in the hard tissue did not significantly change in the non - extraction group based on paired t - test (p=0.056) but slightly decreased in the extraction group (p=0.204). other measurements were the same in the two groups and based on repeated measures anova, the changes in the two groups were not significant. a significant degree of correlation existed between horizontal linear movements of b point (b - np) and b point (b-np) (p<0.001, r=0.779). similarly, horizontal linear movements of pog point (pog - np) and pog point (pog-np) correlated significantly (p<0.001, r=0.937). correlation between soft and hard tissue vertical linear movements of b point indicated by distance from b to constructed frankfurt horizontal plane or fh (sn 7) correlated significantly with b point indicated by b-sn (p<0.001, r=0.842). the same was true for vertical linear movements of pog by pog - sn7 and pog by pog-sn7 (p<0.001, r=0.806). there was a significant degree of correlation between rotational movements of b point with snb and b point with snb (p=0.001) and also between rotational movements of pog (snpog) and pog (snpog) (p=0.001). this study evaluated the hard and soft tissue profiles of patients before and after orthodontic treatment. standard cephalometry was performed for assessment of facial hard and soft tissue changes in the mandible and chin area between the two groups of patients treated with and without tooth extraction. the results showed no significant differences in horizontal or vertical changes in b point and pog in hard tissue or their corresponding points of b and pog in the soft tissue between the two treatment groups. angular changes in b point and pog in the hard tissue were the same in the two groups (as reduction in snb and sn pog angles). similar increasing changes in y - axis angle in both extraction and non - extraction patients and reduction of snb and snpog in the two groups indicate that the rotational changes of the chin are directly related to orthodontic treatment and not to extraction of premolar teeth. in terms of alterations in the chin area, changes in depth before and after treatment were observed in both groups. considering the similar soft tissue changes of the symphysis depth in the two groups and increased symphysis depth in the hard tissue of patients in the non - extraction group, we may conclude that soft tissue retraction in this area causes a slight increase in thickness of the underlying hard tissue during treatment ; whereas, in extraction patients, the muscles of this area are relaxed and may remove the pressure from the area leading to no increase in the symphysis depth. in a study by sharma on changes of a and b points in the hard tissue and a and b points in the soft tissue following extraction of the four first premolars and retraction of incisors, it was found that pre- and post - treatment changes in these patients were significant in both b and b points. point b and point b were retracted by 2.1 mm and 1.2 mm, respectively. in the current study, the trend of changes in b and b was the same in the two groups and these points were retracted. however, these changes in our study were not statistically significant (tables 2 and 3). in another study by al - abdwani, on changes in a and b points in the hard tissue of patients treated with retraction of incisors, changes in b point (before and after treatment) were significant. in response to 10 retraction of mandibular incisors, backward changes in the horizontal dimension were seen, but no significant change was noted in the vertical dimension. in our study, b point in the two groups had a backward movement in the horizontal dimension ; while, in terms of vertical dimension, extraction patients showed a downward and non - extraction patients demonstrated an upward movement. kachiwala, evaluated the facial soft tissue changes in female patients undergoing extraction and correction of the protrusion of anterior teeth in both jaws and reported that b point had no significant changes after treatment compared to baseline. no significant change was noted in b in the two treatment groups. in the current study, we found no significant differences in symphysis height in the two groups but symphysis depth slightly increased. in a study by singh, changes in the soft tissue contour of the chin area before and after treatment and also five years after completion of treatment were evaluated in extraction orthodontic patients. he reported that the overall soft tissue thickness from b point to menton increased. in our study, changes in the soft tissue thickness (measured from the most anterior point of the soft tissue symphysis to the most anterior point of the hard tissue symphysis) were similar in the two groups and showed a significant reduction in the soft tissue thickness. several studies have investigated the changes in upper and lower lips following the retraction of anterior teeth, and a consensus has reached : by the retraction of anterior teeth, the lips are retracted as well. however, fewer studies addressed symphyseal changes after such treatments. based on our results, changes in b point and pog in both extraction and considering the correlation of the above points with their overlying soft tissue, a significant correlation was observed between the hard tissue and soft tissue changes in both study groups. evaluating the vertical skeletal growth changes in our patients by the sum of bjork parameter indicated no significant changes in extraction and non - extraction groups. in addition, a significant increase in y - axis angle in both groups revealed that contrary to the opinion of some clinicians that extraction of first premolars decreases the vertical facial parameters, such vertical changes could not be attributed to extraction in our study. controversy between different studies may be attributed to various systems and methods applied for orthodontic treatment. in the current study, pre - adjusted 0.022-inch slot brackets with mbt technique was applied, which has been advocated by several authors. in both groups, treated with extraction of the four first premolar teeth and non - extraction, b point and pog had backward movement after orthodontic treatment. changes in b and pog were also directly influenced by the changes in the corresponding points in the underlying hard tissue in moving backward. the mean soft tissue thickness of the chin (measured from the most anterior point of the soft tissue symphysis to the most anterior point of the hard tissue symphysis) was similar in the two groups. orthodontic treatments with and without extraction of premolars caused no reduction in vertical facial dimension. | objectives : this study was designed to assess the changes of the mandible of patients who underwent orthodontic treatment with or without extraction of four premolars.materials and methods : eighteen class i bimaxillary protrusion patients treated with extraction of four first premolars and retraction of anterior teeth and 18 class i non - extraction patients with a mean age of 16.380.4 years were selected. cephalometric analysis was performed before and after treatment. twenty - four variables for analyzing the hard and soft tissues of the mandible were compared between the two groups. repeated measures anova was used for the comparison of the two groups fallowed by paired t - test. the relationship between the soft and hard tissue variables was studied using the pearson s correlation coefficient.results:in both groups, the mean value of angular measurements related to b point and pogonion (pog) decreased with treatment (p<0.05). similarly, the symphysis depth of soft tissue decreased (p=0.008). the mean angular value of y - axis increased in both groups after treatment (p=0.007). the mean changes in hard tissue symphysis depth after treatment were different in the two groups (p=0.021). vertical, horizontal and rotational changes in soft tissue b point (b) and pogonion (pog) followed their underlying hard tissue changes (p<0.05).conclusions : points b and pog showed backward movement after orthodontic treatments in both extraction and non - extraction patients. changes in b and pog were directly influenced by the changes in the corresponding points of the underlying hard tissue. orthodontic treatments with and without extraction of premolars produced insignificant changes in vertical facial dimension. |
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