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malnutrition is present in 1855% of hospitalized patients (sorensen., 2008 ; imoberdorf., studies show that nutritional support to undernourished patients and those at nutritional risk is advantageous (stratton and elia, 2007). european guidelines state that provision of tailored food should be an integral part of patient care (council of europe, 2002 ; kondrup., 2003a, 2003b ; norwegian directorate of health, 2009). however, nutrition is often not given priority in clinical practice (mowe. insufficient knowledge and low commitment among nurses and physicians result in an insufficient focus on nutritional aspects of care (kondrup., 2002 ; bavelaar., 2008 ; dietary parameters are seldom monitored during hospital stays ; neither are they described in patients ' medical records or discharge summaries (bavelaar., 2008 ; meijers., 2009 it is a great challenge to implement nutritional guidelines in hospitals (llido, 2006 ; mowe., 2006, 2008 ; bavelaar., 2008 ; the goals were to increase professional awareness of the importance of nutritional care and to provide proper nutritional care to patients with such needs. to achieve these goals, it was considered necessary to develop guidelines, tools and skills, and to educate nurses and physicians in basic clinical nutrition. responsibilities were defined and a professional framework was established (figure 1) to implement these aspects of nutritional care. an important factor was to increase the flexibility of the food services, leading to the provision of more tempting and nourishing food according to patient needs. the aim of the present study was, by using repeated point prevalence surveys, to evaluate whether the implementation of a new strategy had positive effects on nutritional care in the hospital. we performed a prospective quality improvement program implementing nutritional guidelines through the dedicated nutritional network (figure 1). repeated point prevalence surveys over 2 years made it possible to assess whether practice changed over time the seven further surveys were conducted in 51 departments between june 2008 and november 2009. patients were excluded if they were admitted for bariatric surgery, day - surgery or other day - care procedure. the barriers to proper nutritional care identified by the council of europe (council of europe, 2002) were taken into account when the nutritional campaign was carried out. health care professionals, kitchen staff, patients ' representatives and the hospital management were involved in workshops or the network. the nutritional network included 130 physicians, nurses and nurse assistants, and were organized in three levels (figure 1). they were educated for 2 days in basic clinical nutrition and were then responsible for introducing the guidelines to their units. other amenities included interactive tools like website, e - course in clinical nutrition and dedicated forms in electronic patient journal system. at 0800 hours on the day of registration, administrative patient 's data (name, date of birth, sex and hospital ward) the patients were first included (supplementary information sheet 1, appendix 1), then screened according to the nutrition risk screening 2002 (nrs 2002) (supplementary information sheet 2, appendix 1). if total score was 3, additional questions about nutritional support were answered (supplementary information sheet 3, appendix 1). this was measured as the proportion of patients screened, proportion of patients at nutritional risk with a nutritional plan, that is, who were either under treatment or for whom treatment was planned, and the proportion of patients seen by a dietician. we used the proportion of patients coded with the diagnoses for under nutrition according to the international statistical classification of diseases and related health problems (icd-10) e44 or e46 (world health organization, 2010) to assess the participation by physicians. statistical evaluation included a descriptive analysis, and estimations of prevalence of undernutrition at each survey and the proportion of patients who underwent nutritional treatment. version 9.1 and spss version 17.0 (spss inc., chicago, il, usa). this study was part of a quality improvement project and was exempted from review by regional committee for medical and health research ethics. the patients were not asked to give informed consent, as they were not subject to any experimental interventions. the barriers to proper nutritional care identified by the council of europe (council of europe, 2002) were taken into account when the nutritional campaign was carried out. health care professionals, kitchen staff, patients ' representatives and the hospital management were involved in workshops or the network. the nutritional network included 130 physicians, nurses and nurse assistants, and were organized in three levels (figure 1). they were educated for 2 days in basic clinical nutrition and were then responsible for introducing the guidelines to their units. other amenities included interactive tools like website, e - course in clinical nutrition and dedicated forms in electronic patient journal system. at 0800 hours on the day of registration, administrative patient 's data (name, date of birth, sex and hospital ward) were transferred to a dedicated database. the patients were first included (supplementary information sheet 1, appendix 1), then screened according to the nutrition risk screening 2002 (nrs 2002) (supplementary information sheet 2, appendix 1). if total score was 3, additional questions about nutritional support were answered (supplementary information sheet 3, appendix 1). this was measured as the proportion of patients screened, proportion of patients at nutritional risk with a nutritional plan, that is, who were either under treatment or for whom treatment was planned, and the proportion of patients seen by a dietician. we used the proportion of patients coded with the diagnoses for under nutrition according to the international statistical classification of diseases and related health problems (icd-10) e44 or e46 (world health organization, 2010) to assess the participation by physicians. statistical evaluation included a descriptive analysis, and estimations of prevalence of undernutrition at each survey and the proportion of patients who underwent nutritional treatment. data analysis was performed using the statistical software of sas institute inc., version 9.1 and spss version 17.0 (spss inc., this study was part of a quality improvement project and was exempted from review by regional committee for medical and health research ethics. the patients were not asked to give informed consent, as they were not subject to any experimental interventions. of the total number of 5849 inpatients on the eight occasions, 666 (11%) did not meet the inclusion criteria, and for 1579 patients (27%), the screening was not completed. the proportion of patients screened increased significantly from the first to the last survey, with a range from 5477% (figure 3, p=0.012). the prevalence of nutritional risk was 56% at the first point prevalence survey (january 2008) and varied between 3036% at the subsequent surveys (table 1). in total 1230 patients were identified to be at nutritional risk during the eight surveys. of these, 743 (60%), had a nutritional treatment plan. in 649 cases (53%), the nutritional intervention was started and in 94 cases (7%) nutritional treatment was pending (figure 2). the proportion of patients receiving a nutritional treatment plan varied between 54 and 68%, and did not increase during the eight surveys (p=0.66). those who already received nutritional treatment varied between 47 and 59% over time, and patients at risk whose nutritional treatment was planned but had not yet commenced varied between 5 and 11% during the surveys. only 62 (5%) of the patients at nutritional risk were evaluated and followed up by a dietician. during 2008 and 2009, 1.3% of all adult, somatic inpatients at the hospital were diagnosed with malnutrition diagnoses (e44 or e46). in this study, 649 patients (14.3%) of the eligible patients (n=5183) were qualified for this (at nutritional risk and have got nutritional treatment), and 487 (9.3%) more were in need for such treatment (at nutritional risk and did not get nutritional treatment)., 2180 were identified by the four initial questions (figure 2), while the other 194 were considered not at risk according to the remaining nrs 2002 questions, giving a specificity of 92% to identify not - at - risk patients, with the first four questions. one in three screened patients were at nutritional risk, but only half of the people at risk received nutritional treatment, with no improvement during the study period. the strengths of this study include a large sample of patients and almost complete coverage of relevant wards and patient categories. we used a validated screening tool and the screening data were reported by a standardised electronic form designed for this purpose. an important limitation is that the point prevalence surveys were initiated more than 1 year after the start of the nutritional campaign, and initial changes in nutritional practice could then be undetected. a possible limitation is that the point prevalence surveys themselves must be considered to be, at the same time, both interventions and measurements of the results of these interventions, because, as screening is supposed to improve nutritional practice, it is also a reminder of better nutritional practice. this is supported by the fact that results from repeated point prevalence surveys of hospital infections have demonstrated improved clinical practice (scheel and stormark, 1999 ; sartor., 2005). although screening performance improved, the most important outcome, namely the proportion of patients at nutritional risk who received a nutritional treatment plan did not increase. it could be a problem that information about patients at nutritional risk were not communicated from the nurses who did the screening to the nurses and physicians who were responsible for giving nutritional treatment. another factor is a limited dietician service in the hospital the number of dieticians / clinical nutritionists in norwegian hospitals is among the lowest in western countries (norwegian health directorate, 2007), implying that the physicians and nurses mainly are responsible for the patients nutritional care. nutrition has low priority in the education of medical students in norway (norwegian directorate of health, 2007) and norwegian physicians and nurses reported to have less knowledge and interest for clinical nutrition than their danish and swedish colleagues (mowe., 2008). the interest in nutritional matters is lower in wards not regularly visited by dieticians (thoresen., 2008). based on the experience from this study and other recent publications (mowe., 2008), we suggest that there is a scarcity of nutritional knowledge and of dieticians available. we propose that a greater focus on nutritional education of physicians, both undergraduate and postgraduate, and an increased number of dieticians are important to improve nutritional practice. in norway, central health authorities have developed clinical guidelines for nutritional care in hospitals and nursing homes. performing audits of the implementation of these guidelines and economic incentives, such as diagnosis related groups reimbursement for diagnosing malnutrition, may also help improve practice., 2003a, 2003b ; norwegian directorate of health, 2009 and the hospitals local guidelines) as the first step to individualized nutritional treatment. nutritional screening is one of several time - consuming procedures in a busy hospital and may be easy to neglect. by using the four opening questions in nrs 2002 we identified 92% of the patients not at nutritional risk. as all at - risk patients are screened positive on these first four questions of nrs 2002, there will be no patients at risk who are not detected. the proportion of patients classified to be at nutritional risk, would increase from 34 to 40% when using only the four initial questions. the prevalence of patients at nutritional risk is similar to previous european studies (rasmussen., 2006 ; sorensen., 2008 ; lucchin, 2009) but lower than the 44%, shown by a previous norwegian study (oppedal., 2010). the difference can be due to a bias in our study because 1579 patients (27%) eligible for screening were not screened. the healthiest patients may have a higher likelihood of being screened, because it can be difficult to weight bedridden patients and patients in wheelchairs. it is also a challenge to obtain reliable information about previous weight and food intake from certain patients, for example, with delirium and dementia. it has been reported that patients without anthropometric information in the medical records have higher morbidity, mortality and length of stay (stratton. this study was not designed to assess patient outcomes or improvements in food provided to the patients, but there might have been some general improvement in nutrition in the hospital owing to better and more flexible food services. the point prevalence surveys were easy to perform owing to previous experience with similar surveys on infections. it is a suitable method to draw attention to a common and serious problem in health care and it should be considered as a national quality indicator in clinical nutrition. implementation of nutritional guidelines in this university hospital improved the screening performance, which is an important element in better nutritional care, but did not increase the proportion of patients who received nutritional treatment. one of the three patients was at nutritional risk, but only half of them got nutritional treatment. in order to improve practice, we suggest using only the four initial screening questions in nrs 2002 to identify patients not at risk. we also suggest better education in nutritional care for physicians and nurses, and more dieticians employed to achieve more knowledge about nutrition audits of implementation of guidelines performed by health authorities, better accordance between the screening tool and the icd-10 criteria and specific reimbursement for diagnosing malnutrition may also improve practice. we propose repeated point prevalence surveys to become a national quality indicator in clinical nutrition. | background / objectives : malnutrition is present in 2050% of hospitalized patients, and nutritional care is a challenge. the aim was to evaluate whether the implementation of a nutritional strategy would influence nutritional care performance in a university hospital.subjects/methods:this was a prospective quality improvement program implementing guidelines for nutritional care, with the aim of improving nutritional practice. the nutrition risk screening (nrs) 2002 was used. point prevalence surveys over 2 years to determine whether nutritional practice had improved.results:in total, 3604 (70%) of 5183 eligible patients were screened and 1230 (34%) were at nutritional risk. only 53% of the at - risk patients got nutritional treatment and 5% were seen by a dietician. the proportion of patients screened increased from the first to the eighth point prevalence survey (p=0.012), but not the proportion of patients treated (p=0.66). the four initial screening questions in nrs 2002 identified 92% of the patients not at nutritional risk.conclusions:implementation of nutritional guidelines improved the screening performance, but did not increase the proportion of patients who received nutritional treatment. point prevalence surveys were useful to evaluate nutritional practice in this university hospital. in order to improve practice, we suggest using only the four initial screening questions in nrs 2002 to identify patients not at risk, better education in nutritional care for physicians and nurses, and more dieticians employed. audit of implementation of guidelines, performed by health authorities, and specific reimbursement for managing nutrition may also improve practice. |
eosinophilic enteritis is an uncommon disease of unknown etiology, which can affect any area of the gastrointestinal tract, from the esophagus to the rectum, although the stomach and small bowel are most commonly involved1). it usually presents as colicky abdominal pain, and rarely as an acute intestinal obstruction2, 3) or perforation4 - 6), making the initial diagnosis very difficult. eosinophilic enteritis should be considered in the differential diagnosis of unexplained gastrointestinal symptoms, since most patients with eosinophilic enteritis can be treated successfully with corticosteroid therapy, if the correct diagnosis is made7). development of a new capsule video endoscope, which is small enough to be swallowed and has no external wires, fiber - optic bundles, or cables, has made it possible to acquire images of the whole of the small bowel. it has been proven to be very useful in the diagnosis of small bowel disease in the case of negative gastroscopy and colonoscopy8), suggesting it can contribute to the localization of lesions for laparoscopic biopsy, and thus lead to conclusive diagnoses of eosinophilic enteritis. we present the case of a patient who underwent an emergency laparotomy for acute intestinal obstruction due to ileal eosinophilic enteritis, followed by hematochezia due to mid - to - distal jejunal bleeding, which was visualized by capsule endoscopy. the hematochezia was rapidly controlled by high - dosage steroid injection therapy, which suggests that it was a manifestation of eosinophilic enteritis. a 62-year - old man visited the emergency room complaining of epigastric and periumbilical pain, which had developed 3 hours prior to his admission. the nature of his complaint was colicky pain, but he had experienced neither nausea nor vomiting. the patient 's leukocyte count was 10,420/mm (2.9% eosinophils, normal range [nr ], 0~5%). abdominal computed tomography (ct) examination showed segmental wall thickening of the small bowel and proximal dilatation, mesenteric edema, and focal fluid collection in the adjacent peritoneal cavity (figure 1). however, there was no abrupt transition in the luminal diameter at either end of the pathologic bowel loop, suggesting a radiological abnormality, other than the strangulation normally observed in a case of intestinal obstruction. the radiological differential diagnosis included segmental enteritis of unclear cause, and focal mesenteric ischemia by a certain kind of systemic vasculitis, or post- strangulation state following the relief of obstruction. twelve hours after his admission to the emergency room, the abdominal pain progressed, rebound tenderness developed, and finally, an exploratory laparotomy was performed. exploration revealed edema, congestion, and bluish discoloration of the distal ileum, 50 cm from the ileocecal valve. only a 15 cm segment was involved, and the remaining bowel was seen to be normal. the involved ileal segment was resected, and end - to - end anastomosis was performed. gross examination showed an ill - defined mass - like wall thickening with multifocal erosion of the overlying mucosa, 7 centimeters in length, and the surrounding small intestinal mucosa was moderately edematous. histologically, extensive eosinophilic infiltration was found in the mass - like lesion, which was found from submucosa to subserosa (figure 2). in the surrounding mucosa, there was found to be no evidence of parasites, granulomas, malignancy, vasculitis, or embolism in the surgical specimen, either in the bowel wall or in the mesenteric vessels. two days after the operation, the patient 's leukocyte count decreased to 8,070/mm (8.7% eosinophils). 12 days after the operation, the patient 's total ige was 1,310 u / ml above the normal range (0~100 u / ml), but skin prick test was normal, suggesting no specific allergic etiology. seventeen days after the operation, similar characteristic abdominal pain developed again in the patient 's periumbilical area, but to a milder degree than before the operation. the patient was advised to undergo gastroenterological testing in order to evaluate the abdominal pain, but he refused. instead he (60 kg - weight) received 40 mg intramuscular injections of methylprednisolone acetate for two days, and simultaneously took 10 mg prednisolone three times per day, resulting in improvement of abdominal pain. two weeks after this abdominal pain attack, hematochezia occurred for 4 days, in spite of continuous 30 mg prednisolone per day. the patient experienced dizziness, and his hemoglobin decreased from 13.6 g / dl (nr, 13 - 17 g / dl) to 9.5 g / dl. emergency colonoscopy showed no evidence of bleeding after bowel preparation with colyte, nor did it reveal any definite mucosal abnormality up to the ileocecal valve. although there was no definite intrinsic mucosal lesion, six pieces of blind biopsy were taken from the hepatic flexure and 40 cm above the anal verge, but the pathologic results indicated only nonspecific change. in addition, gastroduodenoscopy up to the 3 portion of duodenum revealed no abnormalities, and there was no evidence of bleeding. on the next day, the initial negative tc - tagged red blood cell scan showed a small amount of bleeding from the right iliac artery 2 hours and 30 minutes after injection of tc - tagged red blood cells, and migration of blood into the right ileal lumen after 4 hours and 30 minutes. however, ct angiography and arteriography, which were taken successively, showed no focus of bleeding, indicating that the bleeding had already stopped, or that the bleeding speed was slower than 0.5 ml / min. on the next day, m2a capsule endoscopy was performed. it showed that multiple hemorrhagic spots were scattered throughout the proximal jejunum (figure 3a). after the normal jejunal segment, abrupt spurting of fresh arterial bleeding was detected in the mid - to - distal jejunum, but no ulcer, mass or vascular abnormalities were detected (figure 3b). the ileum was normal, and the anastomotic site at the ileum was not noticed, suggesting no definite lesion around the previous operation site. just 8 hours after the capsule endoscopy examination, a large amount of hematochezia, dizziness, and diaphoresis occurred, along with a decrease in hemoglobin level, from 9.7 g / dl to 6.9 g / dl. the patient did not take oral prednisolone during the 2 days of examination due to the unavailability of an oral intake state. immediately after the detection of massive hematochezia, intravascular injections of 125 mg methylprednisolone sodium succinate per every 8 hours were started, and an emergency operation was prepared. surprisingly, the hemoglobin increased to 10.7 g / dl with 3 packs of rbc transfusion, suggesting termination of the bleeding. five days later, the methylprednisolone sodium succinate injections were replaced with oral prednisolone treatment, 60 mg per day for 2 days, which was to taper down over a two - week period. the etiology of eosinophilic gastroenteritis is unknown, and a definitive pathologic mechanism has not been elucidated. instead, it is likely that eosinophilic gastroenteritis is not a single entity, but rather a heterogenous collection of disorders -- with varied causes, but with similar clinicopathologic features9). allergic phenomena, particularly food sensitivity, have been proposed, but the evidence for this is limited. although food hypersensitivity (usually to milk) may be found in children with eosinophilic gastroenteritis, the response to dietary elimination is usually disappointing. however, eosinophilic ileitis with perforation can be caused by angiostrongylus (parastrongylus) costaricensis5), and eosinophilic ileocolitis by enterobius vermicularis10), suggesting an allergic pathogenesis. eosinophilic gastroenteritis is generally considered to be a chronic benign disease, but there have been several reports of fatal outcomes11, 12). eosinophilic gastroenteritis is categorized according to three distinct forms (mucosal, mural, and serosal) based on its dominant location in the gut wall13). in the mucosal type, the condition behaves like other forms of inflammatory bowel disease, with diarrhea, cramping, postprandial nausea, vomiting, and periumbilical pain. the mural type is characterized by the localization of tissue injury and inflammatory reaction with abundant eosinophils in the submucosa and muscularis propria. in this case, the clinical presentation consists of intestinal obstruction, with nausea, vomiting, abdominal pain, and distension. the serosal type, which is the rarest form, is characterized by diffuse eosinophilic infilatrates of the gut serosa, and may be associated with eosinophilic ascites. if the eosinophilic infiltration is extensive, there may also be malabsorption, weight loss, enteropathy with protein loss, blood loss, and anemia14). in our case, the initial relevant site was the submucosa and muscle layer in the distal ileum, which is consistent with mural type, and explaining both the obstruction symptoms, and the ct finding of segmental small bowel wall thickening. however, the abdominal pain, reoccurring 17 days after the operation, subsided following moderate doses of steroids, suggests another eosinophilic enteritis - related small bowel involvement. furthermore, the capsule endoscopy showed multiple hemorrhagic spots throughout the proximal jejunum, and spurting of fresh arterial bleeding in the mid - to distal jejunum, far from the anastomotic site. there was no definite ulcer, mass, or vascular abnormality, and this bleeding was rapidly controlled by high - dose injections of steroid, indicating that it was a manifestation of jejunal eosinophilic enteritis, the first bleeding case visualized by capsule endoscopy so far. this spurting of fresh arterial bleeding suggests that eosinophilic enteritis can be fatal if it is not rapidly controlled, as it was in our case. the diagnosis of eosinophilic enteritis is a rather difficult one, especially when it presents as abrupt obstruction, perforation, or bleeding, especially in the small bowel. most diagnoses are made retrospectively and histopathologically, as in our case. if there is a high degree of suspicion of eosinophilic enteritis for a patient with ill - defined abdominal pain, coupled with nonspecific laboratory results and inconclusive radiologic findings, laparoscopy, instead of laparotomy, can be tried for a full - thickness biopsy of the intestine15 - 17). recently, wireless capsule endoscopy has been shown to be useful in the diagnosis of small bowel disease, which is beyond the reach of standard upper endoscopy and colonoscopy. maybe the combined approach of capsule endoscopy for localization of lesion, and laparoscopy for the biopsy can facilitate the early diagnosis of eosinophilic enteritis, hence early steroidal treatment. we report a case of eosinophilic enteritis, presenting as a small bowel obstruction, followed by severe jejunal bleeding, which was visualized by capsule endoscopy. this case suggests that if there are symptoms of eosinophilic enteritis, such as abdominal pain, a period of high - dosage steroid therapy is mandatory, in order to prevent further occurrences of complications such as fatal bleeding. | eosinophilic enteritis is a rare disease characterized by tissue eosinophilia, which can affect different layers of bowel wall. normally, the disease presents as colicky abdominal pain, and rarely as an acute intestinal obstruction or perforation. in this paper, we report a case of eosinophilic enteritis, hitherto unreported, presenting as an ileal obstruction, and followed by jejunal bleeding, which was visualized by capsule endoscopy. a 62-year - old man received a 15 cm single segmental ileal resection at a point 50 cm from the ic valve due to symptoms of obstruction, which were diagnosed as eosinophilic enteritis. seventeen days after operation, intermittent abdominal pain occurred again, and subsided upon 30 mg per day treatment with prednisolone. fourteen days after this pain attack, the patient exhibited hematochezia, in spite of continuous prednisolone treatment. capsule endoscopy showed fresh blood spurting from the mid - to - distal jejunum, in the absence of any mass or ulcer. this hematochezia rapidly disappeared following a high - dose steroid injection, suggesting it was a manifestation of jejunal eosinophilic enteritis. |
a total of 850 specimens collected from 306 patients who had encephalitis included 306 csf specimens, 304 blood samples, 120 throat swabs, and 120 rectal swabs. all samples were stored at 20c before being transported for analysis and thereafter were stored at 70c at the national institute of virology in pune, india. laboratory tests conducted by state government health services of uttar pradesh were negative for bacteria and malaria. according to standard protocol (2), virus isolation was attempted in human rhabdosarcoma (rd) and in baby hamster kidney (bhk) cell lines. separate aliquots were processed in 2 laboratories to maintain quality control and monitor possible contamination during pcr processing. viral nucleic acids were extracted by using viral rna mini kits (qiaamp, qiagen, hilden, germany). rt - pcr was performed for ev by using 5 noncoding region (ncr)specific primers, as has been described (5,6). genotyping was conducted by using rt - pcr of virion protein (vp) 1/2a and vp1 regions and sequencing (7,8). table 1 describes the locations and sequences of the primers used in the assays. ncr, noncoding region of viral genome ; vp, virion protein ; na, not applicable. pcr products were purified by using a gel extraction kit (qiaquick, qiagen). both strands were sequenced by using bigdye terminator cycle sequencing ready reaction kit (applied biosystems, carlsbad, ca, usa) in abi prism 3130 xl genetic analyser (applied biosystems). mega 3.1 software generated the phylogenetic tree by using the neighbor - joining algorithm and kimura 2parameter distance model and applying a bootstrap test that used 1,000 bootstrap replications (9). clinical histories available for 253 of the 306 patients showed fever and altered sensorium in 100.0%, hepatomegaly in 70 (27.8%), splenomegaly in 49 (19.4%), and meningeal signs in 35 (13.9%) of the 253 patients. specimens that were adequate for isolation included 85 of 306 csf specimens, 18 of 304 serum samples, 19 of 120 rectal swabs, and 19 of 120 throat swabs. cytopathic effect was observed in cell cultures inoculated with 4 csf specimens, 2 rectal swabs, 2 throat swabs, and 1 serum sample. electron microscopic examination of cultures infected with 2 csf samples showed picornavirus - like particles 2527 nm in diameter. attempts to detect ev rna in the isolates and clinical specimens used nested rt - pcr in 5 ncr. sequences of amplicons from 3 csf specimens and 2 rectal swabs showed 97.2%98.9% homology with ev-89 (i.e., the strain named banoo-10359, genbank accession no. ay697459) and 95.7%96.9% homology with ev-76 (fra91 - 10369, genbank accession no. sequences from 1 isolate from a csf specimen and 1 isolate from a rectal swab showed 100.0% homology with coxsackie virus b3 (cv - b3) strain 20. one isolate from serum showed 98.3% homology with coxsackie virus b1 (cv - b1) strain samp2.17. sixty - six (21.5%) of 306 csf specimens, 7 (6.4%) of 110 rectal swabs, 4 (3.7%) of 110 throat swabs, and 1 (5.5%) of 18 serum samples showed amplification in 5 ncr of the ev genome. sequences of 64 of 78 (82.0%) pcr products (59 from csf specimens, 4 from rectal swabs, and 1 from a throat swab) showed 97.2%98.9% and 95.7%96.9% homology with ev-89 and ev-76, respectively. ten (12.8%) products (7 from csf, 2 from rectal swabs, and 1 from serum) showed 99.3%100.0% homology with cv - b3 (figure 1). three pcr products, each derived from a throat swab, showed 93.3%96.6% homology with coxsackie virus a (cv - a), echovirus 11, and echovirus 30, respectively. phylogenetic tree based on partial 5 noncoding region sequences of enterovirus (ev) genome detected in cerebrospinal fluid samples from encephalitis patients. specimens are identified by repository serial numbers obtained from the national institute of virology (niv), pune, india. ev, enterovirus ; csf, cerebrospinal fluid ; cv - a, coxsackie virus a ; cv - b, coxsackie virus b ; hev, human enterovirus. isolates from 2 of 5 cell cultures, 2 of 59 csf specimens, and 1 of 4 rectal swabs contained ev-76. two of 4 rectal swabs were characterized as ev-89 on the basis of partial vp1/2a (29173374) or vp1 (26022977) gene sequences. ay697463, ay697464, ay697471, ay697469, ay697462, and ay697468) and 93.6%94.5% homology with ev-89 strain (genbank accession no. ay697459) (figure 2). within ev-76 and ev-89 strains of the study, attempts to amplify vp1/2a or vp1 regions of ev rna detected in most clinical specimens failed despite the use of sensitive primer pairs that have been discussed recently (10). phylogenetic tree based on partial virion protein 1 (vp1) sequences (26022977) detected in enterovirus (ev) isolates and clinical specimens from encephalitis patients. ev, enterovirus ; cv - a, coxsackie virus a ; cv - b, coxsackie virus b ; hev, human enterovirus ; niv, national institute of virology, pune, india. table 2 describes details of clinical findings in the subsets of ev - positive and ev - negative specimens of the patients for whom clinical histories were available. further, hepatomegaly and splenomegaly appeared to be proportionately higher in patients with enteroviral infections than in patients whose specimens were negative for ev and je virus. the viral rna detected in csf samples from patients hospitalized with encephalitis in uttar pradesh showed close identity with the ev-89 and ev-76 that recently were reported as an unusual group classified genetically as group a ev (ev - a) (10). presence of the virus was also confirmed by its isolation and typing. human ev-76 was detected in isolates in 1 rectal swab and 2 csf specimens, and human ev-89 was detected in 2 rectal swabs by using amplification of vp1/2a or vp1 regions. sequence analysis showed nt homology of 92.7%97.7% with bangladesh ev-76 and ev-89 strains recovered from patients with acute flaccid paralysis (afp). the failure of amplification of typing regions in most specimens may be due to a low viral load. evs are known to cause severe neurologic diseases ranging from afp to encephalitis (11). in recent years, southeast asian countries have reported outbreaks of encephalitis caused by ev-71 (12,13). during afp surveillance activities, afp patients infected with echoviruses and coxsackie b viruses also have been detected in india (15). isolation of ev from clinical specimens collected from children with encephalitis in the present study indicates viable virus. detection of ev-89/76 rna in the csf of 20% of the patients suggests the association of these viruses with encephalitis. also, in 10 (3.3%) of 306 patients, co - infections of je virus and ev were detected. further studies are needed to understand the relative contributions of these viruses in causing sporadic and outbreak infections of encephalitis. accumulation of water in a saucer - shaped landscape (terai) and extensive rice cultivation in eastern uttar pradesh and adjoining regions favor the growth of vector mosquito populations and waterborne pathogens. though the source of infection in the present study is unclear, the data warrant active surveillance of encephalitis cases. inadequate hygiene and the unsanitary conditions that prevail in the study region may encourage the spread of ev infections in the community. studies conducted on environmental samples may provide clues related to the dynamics of ev infections in humans. | an outbreak of viral encephalitis occurred in northern india in 2006. attempts to identify an etiologic agent in cerebrospinal fluid by using reverse transcription pcr showed positivity to enterovirus (ev) in 66 (21.6%) of 306 patients. sequencing and phylogenetic analyses of pcr products from 59 (89.3%) of 66 specimens showed similarity with ev-89 and ev-76 sequences. |
obstructive sleep apnea syndrome (osas) is a condition of sleep - disordered breathing, which is characterized by the repetitive complete or partial collapses of the pharyngeal airway during sleep. it has been known to frequently involve middle - aged people and to be found in 2% of women and 4% of men (1). patients with osas usually present excessive daytime sleepiness, unrefreshing sleep, fatigue, and even depression, and these symptoms may lead them to serious work or car accidents (2, 3). it has been reported that osas has numerous comorbidities, such as obesity, diabetes mellitus, coronary heart disease, stroke, congestive heart failure, cardiac arrhythmia, and gastroesophageal reflux (4 - 7). in addition, it is also an independent risk factor for hypertension (6, 8) and has a close relationship with atherosclerotic cardiovascular disease (7). although the exact pathophysiological mechanisms are not yet fully understood, repetitive reduction of blood oxygen saturation, increased efforts to breathe, increased sympathetic tone and subsequent rennin - angiotension - aldosterone system are considered to be involved in the development of cardiovascular diseases (7). therefore, the assessment of cardiac functions in osas patients is an essential step in clinical settings. heart rate variability (hrv) analysis has been widely used to non - invasively evaluate cardiac autonomic functions. investigators have demonstrated that abnormal hrv is associated with increased mortality or adverse cardiac events and that the analysis of hrv can be a way of predicting sudden arrhythmic death, myocardial infarction, angina pectoris, stroke mortality, and even rapid progression of atherosclerosis in animals (9 - 12). changes of hrv parameters were also reported in osas patients (13 - 15), and hrv analysis has been proposed as a screening tool for osas (16). however, there are numerous indices or variables in time or frequency domain analysis of hrv, and researchers have reported slightly different findings in their studies. if there is a good index which correlates well with the severity of osas symptoms and also reflects increased cardiac risk, it helps us better understand the pathophysiology of increased cardiovascular morbidity in osas, and can be a useful tool for clinicians. we examined the nocturnal hrv of osas patients to find what parameter in time or frequency domain analysis is the best to reflect the severity of symptoms. fifty - nine untreated male osas patients were recruited from two university hospitals in seoul, and their meansd age was 45.411.7 yr. all subjects met the following inclusion criteria : 1) male, 2) less than 61 yr old, 3) normal electrocardiogram at wakefulness, and 4) apnea - hypopnea index (ahi) greater than 15. the patients who were on the antihypertensive treatment or had a diagnosis of hypertension were excluded. other exclusion criteria were previous or current cardiovascular diseases, pulmonary disorders, diabetes mellitus, substance abuse, history of taking alcohol or other drugs within 7 days before polysomnographic study, diagnosis of periodic limb movements during sleep (plms), disorders of autonomic nervous system or endocrine system that can change blood pressure, and history of operations or cpap treatment for osas. the subjects were categorized into two groups, moderate osas group (n=22) and severe osas group (n=37). the former was defined as the subjects with the ahi greater than 15 but less than 30, and the later with the ahi equal to or greater than 30. polysomnographic recordings were done with embla n7000 system (medcare - embla, reykjavik, iceland) using somnologica version 3.3.1 software (medcare - embla, reykjavik, iceland) during the time when the subjects were in bed from light - off to light - on. electroencephalography was monitored using c3/a2 and c4/a1 leads pairs, and o1/a2 and o2/a1 leads were also used to easily detect alpha waves that are useful to see onset of sleep and arousal. the respiratory movements were monitored using the respiratory inductive plethysmographic belts around chest and abdomen. oxygen saturation was measured by a pulse oximeter sensor which was put on the left second finger. the oxygen desaturation event index (odi) was defined as the number of events per hour in which oxygen saturation decreases by 4% or more. hypopnea was defined as a reduction of airflow by 50 - 80% for at least 10 sec associated with either oxygen desaturation of at least 4% or arousals. apnea was defined as an air flow reduction 80% or more for at least 10 sec (17). ahi was calculated by dividing the total number of apneas and hypopneas by the number of hours of sleep. the evaluation of sleep stages was based on rechtschaffen and kales ' study, and episodes of arousals were assessed according to the guidelines in the previous studies (18). electrocardiographic signals acquired by the polysomnographic machine were digitalized with the sampling rate of 250 hz. time domain variables were mean rr, sdnn, sdnn index, rmssd, nn50 count, nn50 of total hr (%), sdann, and hrv triangular index. rmssd is the square root of the mean of the sum of the squares of differences between adjacent rr intervals. sdann is the standard deviation of the averages of rr intervals in all 5-min segments. the sdnn index is the mean of the standard deviation of all rr intervals for all 5-min segments. nn50 count means the number of pairs of adjacent rr intervals differing by more than 50 ms in the entire analysis interval. nn50 of total hr (%) is the nn50 count divided by the total number of all rr intervals. the hrv triangular index means the total number of rr intervals divided by maximum height of the histogram excluding boundaries. in frequency domain analysis, the power was calculated for very low frequency (vlf, 0.0033 - 0.04 hz), low frequency (lf, 0.04 - 0.15 hz), and high frequency bands (hf, 0.15 - 0.40 hz). the lf / hf ratio was also included in the statistics. comparisons between the two groups, moderate and severe osas groups, were made for demographic data, sleep parameters and events, and hrv indices by independent t - test. sleep events in the analysis were ahi, odi, average o2 saturation, arousal index, limb movement and snoring time. partial correlations controlling age and body mass index (bmi) were evaluated for ahi versus hrv indices. fifty - nine untreated male osas patients were recruited from two university hospitals in seoul, and their meansd age was 45.411.7 yr. all subjects met the following inclusion criteria : 1) male, 2) less than 61 yr old, 3) normal electrocardiogram at wakefulness, and 4) apnea - hypopnea index (ahi) greater than 15. the patients who were on the antihypertensive treatment or had a diagnosis of hypertension were excluded. other exclusion criteria were previous or current cardiovascular diseases, pulmonary disorders, diabetes mellitus, substance abuse, history of taking alcohol or other drugs within 7 days before polysomnographic study, diagnosis of periodic limb movements during sleep (plms), disorders of autonomic nervous system or endocrine system that can change blood pressure, and history of operations or cpap treatment for osas. the subjects were categorized into two groups, moderate osas group (n=22) and severe osas group (n=37). the former was defined as the subjects with the ahi greater than 15 but less than 30, and the later with the ahi equal to or greater than 30. polysomnographic recordings were done with embla n7000 system (medcare - embla, reykjavik, iceland) using somnologica version 3.3.1 software (medcare - embla, reykjavik, iceland) during the time when the subjects were in bed from light - off to light - on. electroencephalography was monitored using c3/a2 and c4/a1 leads pairs, and o1/a2 and o2/a1 leads were also used to easily detect alpha waves that are useful to see onset of sleep and arousal. the respiratory movements were monitored using the respiratory inductive plethysmographic belts around chest and abdomen. oxygen saturation was measured by a pulse oximeter sensor which was put on the left second finger. the oxygen desaturation event index (odi) was defined as the number of events per hour in which oxygen saturation decreases by 4% or more. hypopnea was defined as a reduction of airflow by 50 - 80% for at least 10 sec associated with either oxygen desaturation of at least 4% or arousals. apnea was defined as an air flow reduction 80% or more for at least 10 sec (17). ahi was calculated by dividing the total number of apneas and hypopneas by the number of hours of sleep. the evaluation of sleep stages was based on rechtschaffen and kales ' study, and episodes of arousals were assessed according to the guidelines in the previous studies (18). electrocardiographic signals acquired by the polysomnographic machine were digitalized with the sampling rate of 250 hz. time domain variables were mean rr, sdnn, sdnn index, rmssd, nn50 count, nn50 of total hr (%), sdann, and hrv triangular index. rmssd is the square root of the mean of the sum of the squares of differences between adjacent rr intervals. sdann is the standard deviation of the averages of rr intervals in all 5-min segments. the sdnn index is the mean of the standard deviation of all rr intervals for all 5-min segments. nn50 count means the number of pairs of adjacent rr intervals differing by more than 50 ms in the entire analysis interval. nn50 of total hr (%) is the nn50 count divided by the total number of all rr intervals. the hrv triangular index means the total number of rr intervals divided by maximum height of the histogram excluding boundaries. in frequency domain analysis, the power was calculated for very low frequency (vlf, 0.0033 - 0.04 hz), low frequency (lf, 0.04 - 0.15 hz), and high frequency bands (hf, 0.15 - 0.40 hz). the lf / hf ratio was also included in the statistics. comparisons between the two groups, moderate and severe osas groups, were made for demographic data, sleep parameters and events, and hrv indices by independent t - test. sleep events in the analysis were ahi, odi, average o2 saturation, arousal index, limb movement and snoring time. partial correlations controlling age and body mass index (bmi) were evaluated for ahi versus hrv indices. the differences of mean age (47.19.4 vs. 44.512.9 yr) and bmi (26.13.9 vs. 27.83.8 kg / m) were not significant between the moderate and the severe osas groups. the sleep profiles and sleep event data of the subjects were shown in table 1. the proportion of stage 1 sleep was greater in the severe osas group than in the moderate osas group (p=0.003). the mean ahi for the moderate osas group was 21.24.7, and 56.419.8 for the severe osas group. the severe osas group showed a significantly higher odi (p<0.001), lower average spo2 (p<0.001), and higher total number of episodic limb movements (p=0.010) than the moderate osas group. the severe osas group showed higher respiratory (p<0.001) and total arousal indices (p<0.001) with no difference of spontaneous arousal index as compared to the moderate osas group. time domain variables did not demonstrate any differences between the groups except for hrv triangular index (table 2). the hrv triangular index of the moderate osas group was significantly lower than the severe osas group (17.44.7 and 21.67.8 respectively, p=0.026). in frequency domain analysis, total power (p=0.012), vlf power (p=0.038), lf power (p=0.002), and lf / hf ratio (p=0.005) were greater in the severe osas group than in the moderate osas group with no difference of hf power (table 2). in the correlation analysis between ahi and hrv indices controlling age and bmi (table 3), ahi showed positive correlations with total power (rp=0.313, p=0.018), vlf power (rp=0.286, p=0.031), lf power (rp=0.395, p=0.002) and lf / hf ratio (rp=0.610, p<0.0001), but a negative correlation with rr interval (rp=-0.370, p=0.005). the most significantly positive relationship with ahi it is quite proper that the severe osas group had greater oxygen desaturation, arousal indices and lower spo2 than the moderate symptom group because the mean ahi was completely different from each other according to the definition of the groups. the increased ventilatory effort that results from obstructed breathings in apneic or hypopneic episodes causes frequent arousals (7). more frequent arousals in the patients with severe symptoms might prevent them from falling into deep sleep, and it can also explain increased limb movements in this group. in time domain analysis, most parameters failed to make significance in the statistical comparison between the groups. the hrv triangular index can be calculated by the integral of the density distribution divided by the maximum of the density distribution of normal - to- normal (nn) interval. it also reflects the overall amount of variability and has known to be affected by both sympathetic and parasympathetic activity but more influenced by lower bands than higher bands (19). the significant difference of the hrv triangular index in this study can be interpreted to have been affected by the influence of lower frequency component, because hf did not show the difference. although the lf component has been regarded as a parameter reflecting sympathetic activity, it is far from conclusive whether this result about the hrv triangular index means increased sympathetic tone, because not only lf but also vlf power contributed to the significance of total power. in spite of a few previous studies that reported increases of vlf component in osas patients (20, 21) and synchronized vlf behavior with hypoxemia (22), one of the possible explanations for the reason why most time domain variables were not better than frequency domain variables in differentiating the two groups in this study is that frequency domain techniques may be better than time domain analysis in the precise evaluation of changes of sympathovagal balance (19). in the frequency study, all variables but hf power were found to be significantly greater in the patients with severe symptoms. the difference between the groups depended on the power of very low and low frequency bands. it can account for the greater total power in the patients with severe symptoms because hf power revealed no difference. parasympathetic control for heart rate has a very short latency enabling a beat - to - beat basis change, but synaptic norepinephrine mediating sympathetic influence is metabolized relatively slowly (19). in different way from respiratory sinus arrhythmia that occurs at a high frequency, baroreceptor - mediated heart rate variation has a lower frequency variation about 0.10 hz and can be significantly diminished by sympathetic blockade (19, 23). the hf component has been known to be associated with parasympathetic activity, and lf power was proposed as an index that is affected by the activity of sympathetic nervous system. however, there has been no complete agreement about the meaning of the lf component. mostly sympathetic activity or both sympathetic and parasympathetic activities are thought to contribute to the lf component of hrv. the lf finding without a hf change in this study can be thought to implicate increased sympathetic tone in the severe patients compared with the moderate symptoms group. the lf / hf ratio was found to have a better statistical significance for differentiating the two study groups and to have better correlation with osas severity than other variables in frequency analysis. one possible reason for this is that the lf / hf ratio with less contribution of parasympathetic activity would reflect sympathetic activity better than the lf component itself. another possible reason that can explain why the lf / hf ratio demonstrated a better significance than lf power is that the lf / hf ratio is a normalized parameter without an effect of total power that can be variable with experimental conditions. there were some previous studies in which investigators tried to find a relationship between osas severity and hrv parameters. narkiewicz and colleagues found a increased lf / hf ratio, hf power, and normalized lf power in patients with moderate - to - severe osas patients compared to normal controls, and a greater lf / hf ratio compared to mild osas patients (24). gula and colleagues reported that the lf / hf ratio was higher among patients with moderate osa compared to normals and interestingly those with severe osa (25). aydin and colleagues reported that total power, vlf, lf, and lf / hf ratio were higher in patients than those in controls, and that lf and lf / hf ratio were increased in severe osas group compared with mild osas group (21), but yang and colleagues ' study did not find any difference of time or frequency variables between mild - to - moderate and moderate - to - severe osas patients (26). because their methods were different in the criteria for patients classification, length of time series, hours for getting signals, and ways of analysis, direct comparisons of the results can not be justified. however, the increased lf power and lf / hf ratio in osas patients are relatively consistent findings. the temporary reduction of the oxyhemoglobin level in apnea or hypopnea episodes is known to result in the activation of sympathetic nervous system and subsequent stimulation of the rennin - angiotension - aldosterone system. the relationship of osas and systemic hypertension can be attributed to these physiological mechanisms (27). because lf power and lf / hf ratio have been regarded as indices indicating sympathetic tone or sympathovagal balance, it is plausible to assume that the greater ahi, the greater lf or lf / hf ratio. this study suggests that the lf / hf ratio can be an appropriate index estimating the severity of osas symptoms and that it can be a good candidate for a screening tool with an oximetry for apnea - hypopnea syndrome. regardless of its usefulness, there have been continuous efforts to find appropriate screening methods for osas (28 - 30). the reduction of the arterial oxygen level is a direct consequence of apnea and hypopnea, but a screening only with oximetry does not have a good sensitivity (29). the lf / hf ratio may be useful because this study showed that it has a linear correlation with ahi. frequency analysis has been done usually for short - term hrv data because there is a stationary problem in the long - term data, and it often makes the meaning of the data obscure. however, this result found that the lf / hf ratio still has a meaningful relationship with the severity of the symptoms in the long - term hrv. a limitation is that there was not a normal control group in this study, but there seemed to be no disagreement about the increased lf / hf ratio in the patients through previous studies. | the risk of cardiovascular disease is known to be increased in obstructive sleep apnea syndrome (osas). its mechanism can be explained by the observation that the sympathetic tone increases due to repetitive apneas accompanied by hypoxias and arousals during sleep. heart rate variability (hrv) representing cardiac autonomic function is mediated by respiratory sinus arrhythmia, baroreflex - related fluctuation, and thermoregulation - related fluctuation. we evaluated the heart rate variability of osas patients during night to assess their relationship with the severity of the symptoms. we studied overnight polysomnographies of 59 male untreated osas patients with moderate to severe symptoms (mean age 45.4 11.7 yr, apnea - hypopnea index [ahi]=43.223.4 events per hour, and ahi > 15). moderate (mean age 47.19.4 yr, ahi=15 - 30, n=22) and severe (mean age 44.512.9 yr, ahi > 30, n=37) osas patients were compared for the indices derived from time and frequency domain analysis of hrv, ahi, oxygen desaturation event index (odi), arousal index (ari), and sleep parameters. as a result, the severe osas group showed higher mean powers of total frequency (tf) (p=0.012), very low frequency (vlf) (p= 0.038), and low frequency (lf) (p=0.002) than the moderate osas group. the lf / hf ratio (p=0.005) was higher in the severe group compared to that of the moderate group. on the time domain analysis, the hrv triangular index (p=0.026) of severe osas group was significantly higher. ahi was correlated best with the lf / hf ratio (rp=0.610, p<0.001) of all the hrv indices. according to the results, the frequency domain indices tended to reveal the difference between the groups better than time domain indices. especially the lf / hf ratio was thought to be the most useful parameter to estimate the degree of ahi in osas patients. |
relying on previous spatial analysis of bu incidence in akonolinga district, we analyzed a series of cases that occurred in the highest bu - risk area of the district, located along the nyong river upstream of akonolinga (3). we analyzed 562 new cases of bu that originated in this area from january 2002 through may 2012, after aggregation by month of diagnosis. biological confirmation was obtained from the national reference centre for mycobacteria for 354 (63%) cases. the bu incidence rate remained stable over the 10-year period at 2.2 cases/1,000 person - years. median bu incidence peaked in march, and a second peak occurred in september (technical appendix figure 2), but monthly medians did not differ significantly (kruskal - wallis test, p = 0.149). given the specificities (nonstationarity) of the bu case series, wavelet analysis was the appropriate method for analysis (technical appendix). a 1-year periodic signal was identified in the bu - case time series from 2005 to 2011, and this periodicity was statistically significant from mid-2005 to the beginning of 2009 (figure 1). wavelet analysis of buruli ulcer (bu) case series and nyong river flow, january 2002december 2010. a, b) the color gradient indicates how well the wavelet of a given period adjusted with the series (power). the detection of periodic signals was performed within a confidence cone, which excluded the beginning and the end of the series where edge effects would be too likely (black solid line). statistically significant zones are circled with dashed lines, indicating detection of significant periodic signals during the corresponding years. a) wavelet power spectrum for the time series of bu cases : a seasonal signal with a 1-year period was detected from 2005 to 2011 (green to black), and this period was statistically significant from mid-2005 to the beginning of 2009 (dashed contour lines). b) wavelet power spectrum for the nyong river flow : the nyong river flow series exhibits a statistically significant 1-year periodic signal during the whole period. the dashed lines indicate statistically significant association, and the black line the confidence cone. d) phase analysis for the 1-year period (expressed in multiples of) ; bu cases are represented in blue and nyong river flow variables in red. next, we analyzed the links between bu and seasonal changes by using wavelet association and phase analyses between bu case incidence and total monthly rainfall (in mm) or mean nyong river flow (in cubic meters per second). strong seasonality was found in the series of monthly total rainfall and of monthly mean nyong river flow ; a 1-year period and a weaker 6-month period corresponded to the 2 rainy seasons separated by a period of lesser rainfall (the small dry season, mid - july to mid - august) (figure 1 ; technical appendix figure 3). because of its shape, the wavelet detected yearly rainfall oscillations between a minimum in december (dry season) and a maximum in july (the middle of the rainy period) instead of the maximal rainfall months of october and november (technical appendix figure 3). we assessed the association of the incident case signal with environmental variables (technical appendix). the 1-year periodic signal of the bu case series was associated with nyong river flow from the end of 2005 to the end of 2009 (figure 1) and with rainfall from the end of 2005 to the beginning of 2011 (technical appendix figure 3). under the assumption that changes in the environment preceded changes in bu incidence, phase analysis indicated that cases lagged 6 months behind nyong river flow oscillations (figure 1). when the 2 signals were associated, a 9-month lag behind rainfall oscillations was observed (technical appendix figure 3). in the bu - endemic focus of akonolinga, cameroon, significant 1-year seasonal variations in bu incidence occur. the incubation period for bu has been estimated to be 4.5 months when data from australia are used (10) and 3 months when data from uganda are used (7). the median delay between symptom onset and health care seeking was reported to be 5 weeks in akonolinga (interquartile range 312 weeks), yielding a delay between infection and diagnosis of 56 months. given this delay and a finding of bu diagnosis peaks during march april, the number of infections would therefore be highest from august through october (figure 2). such a pattern was observed in the 1970s in uganda (6,7) and cameroon (11) and more recently in cte divoire (5). in low bu - endemicity french guiana, an overseas territory located near brazil at the same latitude as cameroon, periodic peaks after the 2 rainy seasons have been reported (12). schematic representation of the seasonal changes and possible links between the environment, mycobacterium ulcerans presence, human exposure, and buruli ulcer (bu) incidence in the akonolinga district and the nyong river valley, cameroon, 20022012. for better visualization of delays, b) m. ulcerans prevalencein the aquatic environment (percentage of m. ulcerans positive samples) (14). c) estimated abundance of m. ulcerans positive hemipterans (expressed as % of maximum abundance) (14). d) monthly median number of bu cases detected in the akonolinga district, 20022012 (this study). e) selected activities involving contacts with environments in which risk for bu is high (t. giles - vernick, pers. variations in bu incidence result from variations in population exposure (13) combined with variations in environmental presence of m. ulcerans (14). we hypothesize that one of the main drivers of these variations is the seasonal flooding of the nyong river, which rises 35 m from april through november, creating temporary bodies of water and swamps on a vast surface, deeply affecting the ecosystem. although m. ulcerans was identified year - round in specific environments such as permanent swamps, its presence and abundance were maximal during the rainy months, july october (14) (figure 2). prevalence of m. ulcerans in rivers was high at the beginning of the rainy season and was high in flooded areas during the following small dry season and high rainy season (14). human activity patterns follow these seasonal changes, resulting in seasonal variations in exposure to m. ulcerans. in uganda, the contribution of permanent swamps to bu risk and the increased risk associated with temporary swamps during the rainy season have been documented (8). according to residence, age, and/or sex, the inhabitants of the akonolinga district face varying exposures to aquatic environments ; during the period identified as high risk, populations frequent seasonally flooded environments for water collection, fishing, and harvest of dry season cultures (figure 2) (15). during the study period, the intensity of the association between bu incidence and rainfall or nyong river flow varied. the seasonal signal was detected over 5 consecutive years and was strongest when yearly variations in the nyong river flow were lower (2005, 2006, 2008), which could indicate transient forcing of bu incidence by seasonal phenomena. assessment of the effects of lower frequency climatic events, such as el nio southern oscillation, is needed. in french guiana, where bu endemicity is low, such events were shown to affect bu incidence dynamics (12). we showed that bu incidence in this region varies significantly by season and linked these variations to the fluctuations of m. ulcerans occurrence in the environment, which are probably driven by the dynamics of freshwater ecosystems of the nyong river. in akonolinga, during the high rainy season when risk for m. ulcerans transmission seems to be highest, populations should increase their protective behaviors, and case detection efforts should be intensified in subsequent months to ensure early diagnosis and access to care. technical appendix. additional materials, methods, and results for analysis of seasonal patterns of buruli ulcer incidence, central africa, 20022012. | to determine when risk for buruli ulcer is highest, we examined seasonal patterns in a highly disease - endemic area of cameroon during 20022012. cases peaked in march, suggesting that risk is highest during the high rainy season. during and after this season, populations should increase protective behaviors, and case detection efforts should be intensified. |
molybdenum participates in several enzyme reactions including xanthine oxidase, aldehyde oxidase and sulfite oxidase. the molybdenum cofactor (moco) is essential for the activity of these enzymes and is associated with amidoxime reductase in mitochondria. moco deficiency (mocd) causes a severe progressive metabolic encephalopathy with neonatal convulsions, spasticity, opisthotonus, brain atrophy, altered facial morphology and severe developmental disability, spherophakia and dislocated lenses in survivors, associated with deficiency of both xanthine oxidase and sulfite oxidase. histopathology of the brain shows severe loss of neocortical neurons, gliosis and areas of cystic necrosis in white matter, also seen in sulfite oxidase deficiency, suggesting that deficiency of sulfite oxidase causes much of the cerebral pathology. the mocs1a and mocs1b genes encode an enzyme complex that forms cyclic pyranopterin monophosphate (cpmp) from gtp. the mocs2a and mocs2b gene product, in association with a protein encoded by mocs3, convert cpmp to molybdopterin (mpt). cpmp is deficient or absent when there are mutations in the mocs1 gene, while its oxidation product, compound z, is detectable in urine when there are mocs2 mutations (fig. 1). the gephyrin gene product adenylates mpt and adds molybdenum to form moco. when urine amino acids are screened on suspicion of a metabolic disease, an elevated s - sulfo - l - cysteine level suggests either sulfite oxidase deficiency or mocd. an elevation of urine xanthine and low blood uric acid indicate an additional deficiency of xanthine oxidase due to mocd. patients with mocs1a or mocs1b deficiency have been treated with a stable injectable form of cpmp (hitzert., 2012, veldman., 2010), but with mocs2 mutations supplementation with cpmp is ineffective. pyridoxal-5-phosphate is sequestered by elevated levels of the cyclic form of alpha - amino adipic semialdehyde (piperideine-6-carboxylate) in mocd, so seizures in mocd might respond to pyridoxine supplementation (struys., 2012). a 3.2 kg full term newborn girl with apgar scores 9 at 1 min and 5 min appeared well until day 2 when refractory seizures, opisthotonus, startle reflexes and vomiting developed. the pregnancy and family history were unremarkable ; the parents were of samoan and caucasian origin. despite treatment with intravenous glucose - saline, phenobarbitone and phenytoin, cranial ultrasound mri showed a thin anterior corpus callosum and mri showed severe hypoplasia of its body and splenium ; there was a slight parallel appearance of the lateral ventricles with mild prominence of the trigone and temporal horns. there was subtle loss of gray / white matter differentiation and cerebral edema with attenuation of surface csf spaces. the deep cerebral veins, the vein of galen and the internal cerebral veins were dilated. a dilated serpiginious vein connected the superior sagittal sinus and vein of galen instead of the usual straight sinus and could indicate a persistent embryonic vein. the weights and measurements were in keeping with the gestational age at autopsy, which confirmed normal external morphology and thinning of the corpus callosum, cerebral edema and congested tortuous meningeal vessels. uric acid, s - sulfo - l - cysteine and xanthine in urine were measured by direct - injection electrospray tandem mass spectrography (veldman., 2010). urine sulfite was measured by a semi - quantitative dipstick test (merckoquant test sulfite, merck chemicals, darmstadt, germany). mutations in mocs2b were identified by pcr amplification of exons and neighboring intronic sequences of leukocyte genomic dna from the patient and her parents and sanger sequencing. mocs2a and mocs2b wild - type (wt) proteins and the mocs2b - s140f variant were recombinantly expressed in escherichia coli and purified to homogeneity. the small subunit of mpt synthase, mocs2a, was expressed and purified as intein - fusion protein with a chitin - domain for subsequent affinity purification and eluted with ammonium sulfide, resulting in the release of activated mocs2a protein with a thiocarboxylated c - terminal tail (gutzke., 2001). mocs2b wildtype and the mocs2b - s140f variant were cloned into pet15b, expressed in e. coli bl21 and purified by ammonium sulfate precipitation and subsequent gelfiltration using superdex 200 size exclusion column. changes in three - dimensional structure of the mutant protein were analyzed by circular dichroism spectroscopy (rudolph., 2001). complex formation of mpt synthase was analyzed by isothermal titration calorimetry using mocs2a and either wt mocs2b or the mocs2b - s140f variant. in vitro mpt synthesis rates were quantified as a function of the concentration of small mpt synthase subunit mocs2a (llamas., 2004). uric acid levels in urine were low during life and at autopsy, and urine xanthine was elevated, while the level of compound z which is normally undetectable in urine was found to be elevated (data not shown). urine s - sulfocysteine (44 mol / l) and s - sulfocysteine : creatinine ratio (231 mol / mmol creatinine) were markedly elevated. two novel mutations of the mocs2 gene in dna from blood of the patient were predicted to impair mrna synthesis or enzyme activity. > t (p.s140f) encoded a substitution of phenylalanine for serine and the other, c.501 + 2delt is predicted to disrupt a splice site. in silico analysis using the crystal structure of bacterial mpt synthase predicted the location of s140 at the end of -stand 6, which is part of a highly conserved sequence motif forming the active site within the mocs2b (e. coli moae) and being involved in binding the c - terminal end of mocs2a (e. coli moad). the exchange of the polar serine residue to the much larger, hydrophobic phenylalanine presumably influences the stability of the central -sheet of mocs2b and the overall assembly of the heterotetrameric mpt synthase complex. following expression and purification, the total yield of mocs2b - s140f was much lower than that for wt mocs2b (fig. consistently, circular dichroism spectroscopy revealed an alteration in the protein folding, given that between 210 and 220 nm a more negative signal was recorded, which suggests changes in the content of helical structures in mocs2b - s140f (fig. these might influence either the oligomerization between two mocs2b protomers or the interaction with the small subunit (mocs2a). therefore, we analyzed the complex formation of mpt synthase by isothermal titration calorimetry using mocs2a and either wt mocs2b or the mocs2b - s140f variant. while in the presence of wt mocs2a an effective complex formation associated with a saturation of heat release was observed (fig. 2c), only minor heat release peaks were seen with mocs2b - s140f (fig. 2d) suggesting a severely affected interaction between both subunits, which could not be quantified. note that wt mocs2b binds mocs2a with a kd = 0.36 0.047 m (fig. this finding identifies a defective association of both mpt synthase subunits as a major disease - causing mechanism. finally, we determined in vitro mpt synthesis rates as a function of the concentration of small mpt synthase subunit mocs2a. while wt mocs2b showed an effective mpt synthesis (determined by the oxidation product forma, fig. 2e), mocs2b - s140f was only able to produce low levels of mpt at high concentrations of mocs2a. the differential diagnosis of mocd includes deficiency of sulfite oxidase and pyridoxine - dependent epilepsy (struys., 2012). mocd can be associated with a number of morphological abnormalities of the brain and face. it is important to emphasize that some of the reported changes can be similar to those seen in neonates with hypoxic ischemic encephalopathy, so metabolic investigations should not be neglected in cases of presumed intrapartum hypoxia (topcu., 2001). investigations should include screening of amino acids in urine, which would identify high levels of s - sulfo - l - cysteine in mocd, associated with high urinary xanthine and low levels of plasma uric acid. the detection in urine of compound z confirms the diagnosis of mocs2 deficiency, and facilitates decisions about treatment. exogenous cpmp only works in cases with mocs1 deficiency who can not synthesize cpmp, and could potentially slow or stop the progression of disease (veldman., 2010), although seizures and cramped synchronized general movements have been observed on day 1 in a baby diagnosed prenatally with a mocs1 mutation (hitzert., 2012), so it is possible that irreversible brain damage occurs prenatally. in this case, protein expression experiments confirmed that the s140f mutation severely reduces complex formation of mpt synthase. as some residual activity is detectable in vitro, a milder presentation with low levels of enzyme activity might be considered in this case. in vitro analysis of expression of the allele containing the splice site mutation was not possible for this patient, although the wild type human sequence at both c.419 and c.501 + 2 is conserved in several species (table 1) (anonymous, 2014). biochemical testing for recurrence in a future pregnancy could include measurement of s - sulfo - l - cysteine level or sulfite oxidase activity in chorion villus cells, or of s - sulfo - l - cysteine in amniotic fluid. mutation analysis reassured the parents that treatment with exogenous cpmp was not indicated, as it has only been shown to help babies with mocs1 mutations. the child died before the potential benefit of pyridoxine supplementation was published (struys., 2012). | backgroundmolybdenum cofactor deficiency (mocd) is a severe autosomal recessive neonatal metabolic disease that causes seizures and death or severe brain damage. symptoms, signs and cerebral images can resemble those attributed to intrapartum hypoxia. in humans, molybdenum cofactor (moco) has been found to participate in four metabolic reactions : aldehyde dehydrogenase (or oxidase), xanthine oxidoreductase (or oxidase) and sulfite oxidase, and some of the components of molybdenum cofactor synthesis participate in amidoxime reductase. a newborn girl developed refractory seizures, opisthotonus, exaggerated startle reflexes and vomiting on the second day of life. treatment included intravenous fluid, glucose supplementation, empiric antibiotic therapy and anticonvulsant medication. her encephalopathy progressed, and she was given palliative care and died aged 1 week. there were no dysmorphic features, including ectopia lentis but ultrasonography revealed a thin corpus callosum.objectivesthe aim of this study is to provide etiology, prognosis and genetic counseling.methodsbiochemical analysis of urine, blood, sanger sequencing of leukocyte dna, and analysis of the effect of the mutation on protein expression.resultsuric acid level was low in blood, and s - sulfo - l - cysteine and xanthine were elevated in urine. compound z was detected in urine. two mocs2 gene mutations were identified : c.501 + 2delt, which disrupts a conserved splice site sequence, and c.419c > t (ps140f). protein expression studies confirmed that the p.s140f substitution was pathogenic. the parents were shown to be heterozygous carriers.conclusionsmutation analysis confirmed that the mocd in this family could not be treated with cpmp infusion, and enabled prenatal diagnosis and termination of a subsequent affected pregnancy. |
many authors have discussed the importance of measuring cardiac output and then titrating therapy according to these measurements in patients in the operating theatre and intensive care environments. indeed, in some circumstances these measurements have led to changes in therapy that, in themselves, have been associated with improvements in outcomes. the ' art ' or ' science ' of measuring this variable is therefore rightly given significant airplay in the ongoing literature of our specialty. these include methodologies based on indicator dilution or thermodilution, doppler principles, the fick technique and also pulse pressure analysis. the pulse pressure analysis techniques have become increasingly popular due to the rising number of companies now marketing these devices. it is incumbent on us as practicing clinicians to understand the similarities and differences between these devices so that we can ensure that we use techniques that we can rely upon to be accurate and precise in the clinical environment and also then integrate with therapies that are beneficial to our patients. if we step back and look carefully at how these tools are used, then we would purport that there are two different scenarios that could be discussed. this needs an accurate and precise measurement in order to provide useful information [5 - 7 ]. the second scenario is where clinical interventions are titrated against changes in cardiac output - for instance, with a passive leg raise or volume challenge. in this scenario it is less relevant that we have an accurate and precise measurement, although it is more important that we can track the changes in the underlying signal reliably. on the whole, the pulse pressure analysis techniques for estimating cardiac output are better placed at helping us with this second scenario than the first. in order to have an accurate and precise measurement, the relationship between arterial pressure and central impedance needs to be clarified and this usually means having to make an independent measurement as impedance is notoriously difficult to measure. most companies therefore market these devices combined with another method of measuring cardiac output to calibrate the pulse pressure algorithm at baseline for this problem - commonly with either transpulmonary thermodilution or lithium (indicator) dilution techniques. on a beat to beat basis pulse pressure provides a very good surrogate of changes in stroke volume. as the time interval lengthens, however, this relationship becomes less robust as the vascular tone will change, thereby adversely influencing this signal. the same holds true for the measurement of changes in stroke volume and/or cardiac output from pulse pressure tracking techniques. over time many of the competing influences on the systemic vasculature will alter - level of preload, compliance, arterial resistance, and so on this makes the assumption that changes in the arterial pressure signal directly relate to changes in flow less robust. on a beat unfortunately, these tools are rarely used over a beat to beat basis and are more commonly used over a period of time that may be 30 minutes or perhaps over an hour. if we look at the variety of methodologies used for giving a fluid challenge we can see this all too vividly. after 60 minutes it is quite possible that the vascular tone has changed significantly, thereby raising the question as to whether the change in flow estimated from the pressure signal is real or artefactual. in order to understand this problem a number of authors have investigated these techniques under changing circulatory conditions. in an elegant study, marquez and colleagues demonstrated that the lidcoplus algorithm, when compared against aortic flow probes, was able to track changes in stroke volume in response to a venous occlusion, although there tended to be an underestimation at higher values. yamashita and colleagues assessed how the precision of the algorithms was maintained under therapeutic vasodilatation with prostaglandin e1 during cardiac surgery. they tested the lidco plus and the pulse contour method of the piccoplus versus the intermittent thermodilution of the pulmonary artery catheter. these studies suggested that after significant haemodynamic change (vasodilatation), the algorithms may underestimate the cardiac output and therefore not give a reliable estimate in the change of the signal. more recently, monnet and colleagues assessed how the piccoplus and the vigileo (v1.10) handle vasoconstriction induced by infusion of norepinephrine. they concluded that the vigileo algorithm was less able to track the changes in cardiac index during these situations. a further important consideration from all of these studies is that each algorithm, or algorithm update, will behave differently and will require independent validation. this can be seen in the meta - analysis published by mayer and colleagues looking at the new and older versions of the vigileo algorithms where dramatically differing levels of accuracy and precision were seen. it seems clear that if these devices are to be used to be able to track changes in cardiac output induced by changes in preload, then much care must be taken to ensure that in addition there are no major influences from altered vascular tone. the only way of ensuring this is to make the time interval between measurements short - perhaps minutes rather than hours. if we want to assess the circulation over longer time intervals, then a measurement independent of pulse pressure analysis needs to be included to compensate for these changes in vascular tone. when designing methodologies for assessing the response to a passive leg raise, an end expiratory occlusion, a valsava manoeuvre or a fluid challenge this message needs to be understood. perform the intervention quickly and the monitor should be able to track the change reliably and the correct interpretation should be made. | pulse pressure analysis algorithms are commonly used to measure cardiac output and to allow for the rational titration of therapy in critically ill patients. the ability of these algorithms to accurately track changes in stroke volume (and cardiac output) is thus very important. most of the currently available algorithms can provide robust data so long as there is no fundamental change in the vasomotor tone (arterial compliance or impedance). if the tone changes significantly, for instance with vasodilatation or vasoconstriction, then the data become less robust. for this reason, unless there is a mechanism for compensating for changes in vasomotor tone, these algorithms are best used only over short time periods in order to get the most accurate and precise data on changes in cardiac output. |
social value orientation characterizes individual differences in anchoring attitudes towards the division of resources. here, by contrasting people with prosocial and individualistic orientations using functional magnetic resonance imaging, we demonstrate that degree of inequity aversion in prosocials is predictable from amygdala activity and unaffected by cognitive load. this result suggests that automatic emotional processing in the amygdala lies at the core of prosocial value orientation. |
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viral hepatitis due to hepatitis b virus (hbv) is a major worldwide public health concern leading to acute and chronic liver disease including cirrhosis and hepatocellular carcinoma (hcc) (14). it is currently estimated that over 2.5 billion people are exposed and over 350 million people are chronically infected with the virus and that 1.2 million people die annually from hbv - related disease (57). the prevalence of hbv is known to be higher through asia and the middle east, africa, south america and the mediterranean countries. in these regions, transmission occurs mainly through vertical and horizontal routes. in north america and northern europe, where hbv prevalence is lower, sexual and intravenous drug use are the major modes of transmission (8,9). there are few reliable predicators for the risk of developing serious consequences of hbv infection such as host - related factors (gender, age at infection, degree of liver damage at presentation and immune competence), environmental factors (alcohol consumption, co - infection with other viruses such as hiv and hcv and drug therapy) and hbv - related factors (serological markers, viral load and persistence of viral replication). hbv is currently classified into eight genotypes (a h) based on sequence divergence over the entire genome exceeding 8% at the nucleotide level (1012). additional variability in the genome has been shown to arise as a result of the natural emergence of strains which may have a selective advantage during the course of chronic hbv infection in a patient, e.g. precore mutants, deletions in the core gene, pres1 and pres2 regions [for a review see (15) ]. it is speculated that these variants are driven by the immune system but it currently remains unknown which, if any are clinically significant. sequence evolution driven by external pressures such as the introduction of immunization programmes and more recently antiviral treatment has also given rise to a number of mutations within the viral polymerase and envelope regions [for a review see (16) ]. although in vitro studies have provided significant information into understanding the clinical significance of sequence changes, these data remain limited to a few specific mutations (17,18). the development of databases containing detailed genetic sequences of human pathogens provides a new point of departure for the investigation of host parasite relationships. using bioinformatics techniques it is possible to assess pathogen relatedness and likely evolutionary pathways, and to examine the pathways of sequence evolution of an agent in response to a particular selection pressure such as antiviral treatment. furthermore, building a repository for such data allows for the monitoring of the distribution and variability of hbv strains at regional, national and global levels, which is of importance in an increasingly mobile population. furthermore, such data provide a powerful tool in the public health setting when investigating hbv transmission events and outbreaks. owing to these considerations there is an urgent need to develop trusted databases to store reliable and curated data on the public health aspects of hbv infections and to develop appropriate methods and tools to extract and analyse the stored data and report the information. we present here hepseq (), a freely accessible web resource on the public health aspects of hbv infection with specific focus on epidemiological, virological, clinical, nucleotide sequence and mutational aspects of hbv infection. hepseq is able to summarise and link large volumes of data and present those in a visually intuitive format. moreover hepseq provides a resource to support detection of variants in patients from different parts of the world, to help monitor the dynamic of hbv variants during therapy and potentially to contribute to re - design of diagnostic assays. a front - end apache web server serves content to the client browsers. a middle dynamic content processing and generation layer consists of php, cgi and perl scripts and specialized programs written in c (e.g. for sequence alignment). finally a backend database has both datasets and relational database management system (rdbms). during the design and development of hepseq, initially all the necessary requirements for a comprehensive public health database on epidemiological, clinical and molecular markers were identified through many discussions with the stakeholders (clinicians and lab scientists) and then data modelling was undertaken. after reviewing and improving the resultant model several times, a data schema capable of catering to diverse sources and formats of data was evolved and implemented as a relational database using postgresql open source database management system on a linux operating system server. this schema consists of patient, sample, gene and mutant tables, which have one to many relationships between them. this schema enables multiple mutations to be associated with a nucleotide sequence, multiple nucleotide sequences to be associated with a sample and multiple samples to be associated with a patient. the epidemiological, virological, clinical and nucleotide sequence data were mainly collated from the participating centres and manually checked before insertion to the database. caldicott standards are recommended by the department of health, england and govern the use and transfer of patient - identifiable information from national health service (nhs) organizations to other nhs and non - nhs organizations (the caldicott report is available online at and confidentiality : nhs code of practice is available at). ambiguities in data were raised with the contributors and only stored in the database once these were resolved. the first of these sections contains the information pages accessed through the top navigational bar. these pages display a summary of the current contents in the repository, an overview of the hepseq system, and contact information. to facilitate the dissemination of news, events of interest to the public health community and latest publications on hepatitis, really simple syndication (rss) feeds from different sources are compiled and displayed on the news and events page. updates relating to hepseq are also rendered as rss feeds and are available for download and display with a rss newsreader from the overview page. information pages on clinical, epidemiological and sequence display real - time data from the current database records as pie and bar charts (figure 1). sequence matcher (c) matches a user input sequence and produces a tabular format results page (d), from which detailed individual patient record (e) or the sequence record (f) can be obtained. users can either access all the records in a tabular form or access any detailed individual record by specifying a patient, sample, gene or mutant identifier. the search page provides all the fields available in the database and distinct entries of those. through this page any combination of the specific fields in the database can be searched by user - created unique queries and from the resultant tabular data, individual detailed records can be viewed. researchers interested in submitting data to hepseq can contact the curators by email detailing the nature, type and amount of data they wish to submit. after individually determining the best possible mechanism to submit data, the data will be bulk loaded into a temporary table and manually curated. after reconciling any inconsistencies in the data with the submitter the third section of the web interface provides graphical tools to dynamically generate pie and bar charts from any specified field or a pair of fields. this tool can easily find the associations between different factors (e.g. outbreak and genotype) and display those in a meaningful manner. another tool in this section integrates the google map api with the database and a specific parameter relating to the geographical area can be viewed. the sequence matcher tool allows a user to input a dna sequence and search it against all the sequences deposited in the hepseq. protocols for identical matching as well as for matching near - identical strain sequences are available. the identical matching is implemented through the string match functions of the programming language and is very fast. near - identical matching allows the user to pick a pairwise sequence matching algorithm from three available methods : smith waterman (19), needleman the tabular format of the result is linked to individual records as well as alignments. the benefit of this tool is that a user - input sequence can be linked to related sequences and to potentially related cases. wunsch (20) algorithm against all the reference sequences and highly scoring matches (> 98% sequence similarity) with statistical significance are reported. if the input sequence is not a recombinant sequence then an unambiguous genotype can be predicted to the given sequence. in this tool genotyping the reference sequences were assembled from the sequences downloaded from genbank and the sequences in the hepseq system and validated using phylogenetic analysis. the mutation marker tool allows sequences grouped by different parameters (e.g. genotype) to be displayed as multiple alignments, allowing sequence differences and gaps to be visualized. this also annotates the alignment with clinically important specific mutations related to vaccine escape or antiviral resistance. the current release of hepseq is dedicated to be a comprehensive online resource for public health aspects of hbv infection and offers a platform for further multi - factorial analysis of hbv infection. in this current format the database system is useful as an extensive library of hbv sequences well annotated with clinical and epidemiological data. the first priority in future hepseq development is to increase the number of data contributors and users and trying to reach and receive data from almost all the centres and laboratories involved in hbv infection studies. this will make hepseq a truly global repository of hbv infection data and a public health portal for hbv infection studies. as the quality and consistency of the data availability is the best indicator of any database system, in future, increased focus will be towards data quality. in addition to the manual curation currently automatic scripts also report on the quality of the data. we would want to extend this to include the quality of the nucleotide sequences deposited in the system and to report on the sequencing errors that might have occurred. this has implications in assigning correct genotype to a sequence and also in the subsequent multi - factorial analysis of data. to achieve this although automated, web - based approaches can be used to a certain extent, manual curation remains the gold standard until the acceptable parameters for automated analysis are generally agreed. there is a need to explore approaches other than simple percentage sequence identities between strains for genotype assignment as these can be unreliable where partial (rather than complete) genomic sequences are available. approaches such as integrating position sensitive scoring matrices (pssms), recently applied to hbv (22) with the current pairwise sequence comparisons will be explored. there is also a need to present the sequence analytical tools (genotyping and sequence alignment tools) as a webservice, so that other web - based systems could utilize these services without duplicating effort. | hepseq is a repository for an extensive library of public health and molecular data relating to hepatitis b virus (hbv) infection collected from international sources. it is hosted by the centre for infections, health protection agency (hpa), england, united kingdom. this repository has been developed as a web - enabled, quality - controlled database to act as a tool for surveillance, hbv case management and for research. the web front - end for the database system can be accessed from. the format of the database system allows for comprehensive molecular, clinical and epidemiological data to be deposited into a functional database, to search and manipulate the stored data and to extract and visualize the information on epidemiological, virological, clinical, nucleotide sequence and mutational aspects of hbv infection through web front - end. specific tools, built into the database, can be utilized to analyse deposited data and provide information on hbv genotype, identify mutations with known clinical significance (e.g. vaccine escape, precore and antiviral - resistant mutations) and carry out sequence homology searches against other deposited strains. further mechanisms are also in place to allow specific tailored searches of the database to be undertaken. |
stress is described as any combination of environmental conditions (such as temperature, relative humidity, immobility, and solar radiation) that will cause the temperature of the environment to be higher than the temperature range of the animal s temperature zone / thermal neutral zone. temperatures above the thermal neutral zone initiate physiological, anatomical, and behavioral responses the aim of which are to increase heat loss and decrease heat production in trying to maintain the body s temperature within its normal range. episodes of restraint stress for two hours caused great loss of willingness in rats to eat (3). there is evidence that shows decreased weight gain in broiler chicks that were raised under heat stress conditions (4). immobility stress has been shown to have negative effects on some blood parameters in mice (5). peppermint (mentha piperita) is a medicinal plant of the labiatae family, and it possibly originated in eastern asia. peppermint has been used extensively in herbal medicines, and it s believed that peppermint is efficient in the immune system and in fighting secondary infections (6). peppermint has biological activities, such as anti - bacterial, anti - fungal, and anti - oxidant properties (6). it has been reported that mint genera have adverse effects on induction of oxidative stress (7). the dietary inclusion of peppermint oil had benefical effects on some blood biochemical parameters of mice under immobility stress (5, 8). thus, the current study was conducted to determine the effect of different levels of peppermint extract on body weight and the blood s biochemical parameters in adult male wistar rats. to prepare the peppermint extract, we collected fresh leaves of peppermint in jiroft city, kerman, iran. the plants were kept by the department of pharmacy at shiraz university of medical sciences. the peppermint was dried at 45 c for five days, and, then, it was ground into tiny particles of powder and homogenized in 96% ethanol at a ratio of 1 part peppermint plant to 10 parts of ethanol. the mixture was left to saturate for four days at 25 c by occasional shaking and stirring. then, the mixture was filtered through filter paper, and the filtrate was intensified at low pressure and 45 c to prepare a dark, gummy, green extract. then, we dissolved the extract in tween 20 (10%, w / v). this study was performed at islamic azad university, arsanjan branch, located in shiraz province, following the preparation of the peppermint extract, 50 adult, healthy, male wistar rats (aged in 2.53 months, weighing 190210 g) were obtained from the animal house unit for this experiment. the wistar rats were raised in wire - bottom cages at 22 2 c and 5565% relative humidity. we initiated a 12-hr light - dark cycle at least a week before the study began, and the rats were maintained under standard housing conditions with free access to a standard diet and water ad libitum. we recorded their body weights at the beginning and end of the study to determine the changes in body weight that occurred during the tests. the animals were allocated randomly into five groups : t1 (control group, received 0.3 ml distilled water), t2, t3, t4 and t5 received peppermint extract 75, 150, 300 and 600 mg / kg respectively. blood samples were collected and centrifuged (at 2000 g for 10 min) ; serum was obtained for the measurement of glucose, cholesterol, triglycerides, hdl, ldl, albumin, globulin, and total protein by spectrophotometer (shimadzu uv-1700) using a pars azmoon commercial kit package (pars azmoon, co., tehran, iran). we used standard commercial kits for analysis as recommended by the manufacturer of these kits. statistical analyses of the data were done with sas software (version sas 9.1.3.). the data were statistically analyzed with one - way analysis of variance (anova) done through dennett s multiple comparison post - test. the results were presented as mean standard error mean. a value of p 0.05). the serum contents of cholesterol, triglycerides, ldl, and glucose were significantly lower in the rats in groups t3, the peppermint extract at high levels had increased effects on the blood parameters (t4 and t5 vs. t3). as the results indicated, the peppermint extract increased the body weight gain in wistar rats during exposure to high temperature. as mentioned before, stress had negative impacts on appetite and reduced appetite may decrease gains in body weight (3). unfortunately, we could find no study in the literature that showed the effect of peppermint extract on body weight in rats reared under heat stress condition. in similar study, akbari and torki showed that adding peppermint oil had no significant effects on body weight gain in broiler chicks reared under heat stress condition (8). parallel to our findings, they reported that supplementing their diets with peppermint powder at levels of 4 gm / kg increased body weight gain in broiler chicks (9). there is evidence that shows that adding herbal plants stimulates appetite, the secretion of gastrointestinal fluids, and improves digestion and absorption, thereby producing gains in body weight (10). there is evidence that shows that high temperature can break the homeostasis of cecal microflora and cause damage to the intestinal mucosa and immune function in animals ; however, extracts also reduce potentially pathogenic bacteria and cause a shift in the composition of the gut s microflora towards more beneficial bacteria, making it possible to increase body weight (11). this increase may be due partly to the menthol activity of peppermint, because menthol is an appetite - enhancing substance. in this study, peppermint extract did not have a significant impact on the serum content of hdl, total protein, globulin, or albumin. the peppermint supplements had no significant effect on the serum content of hdl in broiler chicks (9). peppermint essential oil and chromium picolinate improved the serum content of albumin in heat - stressed broiler chicks (8). the absence of concurrence among these studies may be a result of the levels at which the extract was administered. in addition, other variables, such as differences in background of the selected animals, the types of animals or genera and age, and the severity of the stress may have affected the efficacy of extract usage, and therefore it was difficult to directly assess different studies that used extracts. in this study, administering the peppermint extract at high levels decreased the serum content of ldl, triglycerides, and cholesterol in wistar rats that were kept at high temperature. it seemed that peppermint had anti - lipidemic benefits, but it can not show this benefit at low levels.. showed that peppermint extract decreased the serum contents of ldl, cholesterol, and triglycerides in wistar rats compared with the control group (12). in one human study, peppermint decreased the contents of serum ldl, cholesterol, and triglycerides in university students (13). the decrease of total cholesterol, ldl cholesterol, and total triglycerides of the treatment group might have been related to the involvement of the proposed components in the antioxidant and excess cholesterol protection mechanisms. heat stress can induce the synthesis of free radicals, which can damage cell membranes by lipid peroxidation of polyunsaturated fatty acids in the cell membrane, thereby destroying the integrity of the membrane (14). the idea was confirmed by young. who showed that herbs and spices, along with vitamins c and e (anti - oxidant vitamins) were even more effective at preventing lipid peroxidation in the tissues of birds (15). there was a positive correlation between the total phenol concentration of herbal plants and human low - density lipoprotein oxidation in vitro (16). also, marjani. reported a decrease in the serum content of malondialdehyde (end product of lipid oxidation) in mice reared under immobility stress when fed a diet supplemented by peppermint oil (from 0.90 to 60 mg / kg) (5). we believe that the decrease in the serum content of cholesterol may be a result of inhibition of hmg - coa reductive activity, which is a key regulatory enzyme in cholesterol synthesis. in this study, rats supplemented with peppermint at high levels produced lower serum concentrations of glucose. peppermint reduced the serum concentration of glucose in wistar albino rats compared with control group (17). peppermint and chromium picolinate decreased serum glucose in heat - stressed broiler chicks (8). the antioxidant roles found in peppermint tea may be responsible for hypoglycemic effects (18). there is a significant correlation between the serum content of glucose and the levels of lipids. we believe peppermint extract may influence the insulin - sensitive cell receptors or binding activity. it is well - known that insulin reduces lipolysis in adipocytes and prevents gluconeogenesis, thereby decreasing the serum contents of triglycerides and glucose. this idea was confirmed by xie. who showed that cinnamaldehyde (the active component of cinnamon essential oil) increased the release of insulin (19). supplementation with peppermint extract was effective in improving body weight gain compared with the control group. treatment by peppermint extract did not improve the serum content of hdl, total protein, globulin, or albumin. the results also suggested that supplementation with peppermint extract can reduce the serum concentrations of cholesterol, triglycerides, ldl and glucose triglycerides, and glucose. this study showed, for the first time, that peppermint extract is able to reduce the serum lipids or glucose and increase the body weight of wistar rats kept at high temperatures, thereby helping to protect the rats against the deleterious consequences of lipoperoxidation and potentially ensuring antioxidant potential. | introductionpeppermint is an efficient medicinal plant for the treatment of diseases, and it also can be used to produce raw materials in the pharmaceutical industry. the purpose of the current study was to evaluate the effects of various levels of peppermint alcoholic extract on body - weight gain and blood biochemical parameters in adult male wistar rats.methodsthis experiment was conducted using a completely randomized design (crd). fifty adult, healthy, male wistar rats (ages of 2.53 months ; weights of 190210 g) were allocated randomly into five groups. t1 was the control group in which the rats received 0.3 ml of distilled water). groups t2, t3, t4, and t5 received 75, 150, 300, and 600 mg / kg of peppermint extract, respectively. the rats received daily pretreatment by oral gavages for 21 days. we recorded body weights at the beginning and at the end of the study to determine the changes in the body weights. blood samples were collected for the measurement of glucose, cholesterol, triglycerides, hdl, ldl, albumin, globulin, and total protein. statistical analysis of the data was done by sas software. the data statistically analyzed using one - way analysis of variance (anova), which was conducted through dennett s multiple comparison post-test.resultsthe results indicated that the rats treated with peppermint gained more weight (p < 0.05) and also decreased the serum concentrations of triglycerides, total cholesterol, ldl, and glucose in t3, t4 and t5 than the other groups (p < 0.05).conclusionpeppermint extract had a positive effect on body - weight gain and some blood parameters in adult male wistar rats. the findings showed that peppermint is a crucial substance at high temperature, and future research should be focused on determining the details of the mechanisms involved in producing the observed effects of peppermint extract. |
the major clinical symptoms of migraine include moderate - to - severe pulsatile headaches, often accompanied by nausea and vomiting. optical and acoustic stimuli, as well as some daily activities, are known to exacerbate migraine headaches, whereas a quiet environment and plenty of rest can relieve the headaches. valproate is a broad - spectrum antiepileptic drug that is used to over one - third of epileptic patients. valproate has also been approved by the fda for the treatment of neuralgia and bipolar disorders. valproate can exert a neuroprotective effect and modulates neuronal differentiation and survival, as well as long - term neuroplasticity. in addition, valproate can protect the cortical neurons from spontaneous cell death and improve the behavioral outcomes. valproate is effective in relieving headaches and is proposed to be a potential anti - migraine drug [69 ]. valproate can also be used in the treatment of headaches from medication overuse and as a prophylaxis of episodic migraine. mitochondria are important sites of energy metabolism, especially in the high energy - consuming organs. it has been reported that mitochondrial function is often impaired in patients with migraine, and mitochondrial dysfunction is thus implicated in the pathophysiology of migraine. valproate can be used to prevent and mitigate migraine, but the underlying mechanism remains unclear. in the present study, we explored the effect of valproate on migraine and the underlying mechanism in a rat model of nitroglycerin - induced trigeminovascular activation. valproate was found to attenuate nitroglycerin - induced trigeminovascular activation in rats by preserving the mitochondrial function. male sprague - dawley rats (8 weeks old, weighing around 200 g) were obtained from liaoning changsheng biotechnology co., ltd. (benxi, china) and housed in a controlled environment (232c, 505% relative humidity, and 12 h : 12 h light : dark cycles). forty rats were randomly divided into 4 groups (control, model, model+vp - l, and model+vp - h). rats in the model+vp - l group and model+vp - h group received a low dose of valproate (100 mg / kg in saline) (dalian meilun biotech co., ltd., dalian, china) or a high dose of valproate (200 mg / kg in saline) every day by intraperitoneal injection for 5 days. rats in the control and model groups received an equal volume of saline. on the sixth day, rats in the model, model+vp - l, and model+vp - h groups received an intraperitoneal injection of nitroglycerin (10 mg / kg in saline) (beijing yimin pharmaceutical co., ltd., beijing, china), and rats in the control group received an equal volume of saline. four hours after nitroglycerin injection, the peripheral blood was collected and the levels of 5-hydroxytryptamine (5-ht) and nitric oxide (no) were measured using a 5-ht elisa kit (uscn, wuhan, china) and a total no assay kit (beyotime, haimen, china) respectively. the rats were then sacrificed, and the spinal trigeminal nucleus was obtained for subsequent experiments. the care and treatment of the animals was approved by the animal ethics committee of the first affiliated hospital of harbin medical university. dna was extracted from rat spinal trigeminal nucleus using a dna extraction kit (tiangen, beijing, china) according to the manufacturer s instructions. the mtdna copy number was measured by quantitative real - time pcr according to the methods described previously [1417 ], with the following primers : dn1 forward primer : 5-ttatcctcttatccgtcctc-3 ; dn1 reverse primer : 5-tgttaagtcgaagggagc-3 ; -actin forward primer : 5-agggaaatcgtgcgtgac-3 ; -actin reverse primer : 5-aggaaggaaggctggaag-3. the relative mtdna copy number was calculated using the 2 method. proteins in the spinal trigeminal nucleus were extracted using a total protein extraction kit (wanleibio, shenyang, china). after measurement of the protein concentration with a bca protein assay kit (wanleibio), an equal amount of proteins from each group was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis. subsequently, the separated proteins were transferred onto polyvinylidene fluoride membranes (millipore, bedford, ma), followed by blocking with 5% skim milk. after washing with tbst, the membranes were incubated overnight at 4c with primary antibodies against peroxisome proliferator - activated receptor- (pparg) (1:400, bioss, beijing, china), peroxisome proliferator - activated receptor- coactivator-1 (pgc-1) (1:1000, abcam, cambridge, uk), mitochondrial transcription factor a (tfam) (1:2000, abcam), b - cell lymphoma-2 (bcl-2), bcl-2-associated x protein (bax) (1:400, boster, wuhan, china), and -actin (1:1000, santa cruz, dallas, tx). thereafter, the membranes were washed with tbst and then incubated with the corresponding horseradish peroxidase - labeled secondary antibody (1:5000, wanleibio) at 37c for 45 min. the membranes were washed with tbst again and the signals were detected with an ecl detection system (wanleibio). the gray intensity of the target proteins was analyzed with gel - pro - analyzer software, and the relative protein level was calculated using -actin as the internal reference. the spinal trigeminal nucleus was homogenized in 9 volumes of pbs. after freezing and thawing 3 times, the protein concentration in the supernatant was measured with a bca protein assay kit, and the atp level was determined with an atp assay kit (jianchengbio, nanjing, china) according to the manufacturer s protocol. the protein concentration in the supernatant of spinal trigeminal nucleus homogenate was determined, and the activity of cytochrome c oxidase in the supernatant was detected with a rat cytochrome c oxidase assay kit (whb, shanghai, china) according to the manufacturer s instructions. after measurement of protein concentration, the supernatant of tissue homogenate was used for determining the ros level using an ros assay kit (jianchengbio) according to the protocol. the mitochondrial membrane potential was assessed by staining with the jc-1 probe, followed by fluorescence microscopy or flow cytometry. the cells were incubated with the jc-1 working solution from the jc-1 kit (keygen, nanjing, china) at 37c for 20 min. the cell images were captured under a fluorescence microscope (olympus, tokyo, japan), and the fluorescence signals were quantitated by flow cytometry (bd, franklin lakes, nj). the differences between the control group and the model group were analyzed using student s t test, and differences between the model group, model+vp - l group, and model+vp - h group were analyzed using one - way analysis of variance followed by bonferroni s multiple comparison test. male sprague - dawley rats (8 weeks old, weighing around 200 g) were obtained from liaoning changsheng biotechnology co., ltd. (benxi, china) and housed in a controlled environment (232c, 505% relative humidity, and 12 h : 12 h light : dark cycles). forty rats were randomly divided into 4 groups (control, model, model+vp - l, and model+vp - h). rats in the model+vp - l group and model+vp - h group received a low dose of valproate (100 mg / kg in saline) (dalian meilun biotech co., ltd., dalian, china) or a high dose of valproate (200 mg / kg in saline) every day by intraperitoneal injection for 5 days. rats in the control and model groups received an equal volume of saline. on the sixth day, rats in the model, model+vp - l, and model+vp - h groups received an intraperitoneal injection of nitroglycerin (10 mg / kg in saline) (beijing yimin pharmaceutical co., ltd., beijing, china), and rats in the control group received an equal volume of saline. four hours after nitroglycerin injection, the peripheral blood was collected and the levels of 5-hydroxytryptamine (5-ht) and nitric oxide (no) were measured using a 5-ht elisa kit (uscn, wuhan, china) and a total no assay kit (beyotime, haimen, china) respectively. the rats were then sacrificed, and the spinal trigeminal nucleus was obtained for subsequent experiments. the care and treatment of the animals was approved by the animal ethics committee of the first affiliated hospital of harbin medical university. dna was extracted from rat spinal trigeminal nucleus using a dna extraction kit (tiangen, beijing, china) according to the manufacturer s instructions. the mtdna copy number was measured by quantitative real - time pcr according to the methods described previously [1417 ], with the following primers : dn1 forward primer : 5-ttatcctcttatccgtcctc-3 ; dn1 reverse primer : 5-tgttaagtcgaagggagc-3 ; -actin forward primer : 5-agggaaatcgtgcgtgac-3 ; -actin reverse primer : 5-aggaaggaaggctggaag-3. the relative mtdna copy number was calculated using the 2 method. proteins in the spinal trigeminal nucleus were extracted using a total protein extraction kit (wanleibio, shenyang, china). after measurement of the protein concentration with a bca protein assay kit (wanleibio), an equal amount of proteins from each group was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis. subsequently, the separated proteins were transferred onto polyvinylidene fluoride membranes (millipore, bedford, ma), followed by blocking with 5% skim milk. after washing with tbst, the membranes were incubated overnight at 4c with primary antibodies against peroxisome proliferator - activated receptor- (pparg) (1:400, bioss, beijing, china), peroxisome proliferator - activated receptor- coactivator-1 (pgc-1) (1:1000, abcam, cambridge, uk), mitochondrial transcription factor a (tfam) (1:2000, abcam), b - cell lymphoma-2 (bcl-2), bcl-2-associated x protein (bax) (1:400, boster, wuhan, china), and -actin (1:1000, santa cruz, dallas, tx). thereafter, the membranes were washed with tbst and then incubated with the corresponding horseradish peroxidase - labeled secondary antibody (1:5000, wanleibio) at 37c for 45 min. the membranes were washed with tbst again and the signals were detected with an ecl detection system (wanleibio). the gray intensity of the target proteins was analyzed with gel - pro - analyzer software, and the relative protein level was calculated using -actin as the internal reference. the spinal trigeminal nucleus was homogenized in 9 volumes of pbs. after freezing and thawing 3 times, the protein concentration in the supernatant was measured with a bca protein assay kit, and the atp level was determined with an atp assay kit (jianchengbio, nanjing, china) according to the manufacturer s protocol. the protein concentration in the supernatant of spinal trigeminal nucleus homogenate was determined, and the activity of cytochrome c oxidase in the supernatant was detected with a rat cytochrome c oxidase assay kit (whb, shanghai, china) according to the manufacturer s instructions. after measurement of protein concentration, the supernatant of tissue homogenate was used for determining the ros level using an ros assay kit (jianchengbio) according to the protocol. the mitochondrial membrane potential was assessed by staining with the jc-1 probe, followed by fluorescence microscopy or flow cytometry. the cells were incubated with the jc-1 working solution from the jc-1 kit (keygen, nanjing, china) at 37c for 20 min. the cell images were captured under a fluorescence microscope (olympus, tokyo, japan), and the fluorescence signals were quantitated by flow cytometry (bd, franklin lakes, nj). the differences between the control group and the model group were analyzed using student s t test, and differences between the model group, model+vp - l group, and model+vp - h group were analyzed using one - way analysis of variance followed by bonferroni s multiple comparison test. after induction of trigeminovascular activation with nitroglycerin, the number of scratching behaviors was recorded. as shown in figure 1a, the number of scratching behaviors in the model group was significantly higher than that in the control group. compared with the model group, the number of scratching behaviors was decreased in the model group rats with valproate pre - treatment. consistent with the number of scratching behaviors, the 5-ht level was decreased and the no level was increased in the model group compared with the control group, and the nitroglycerin - induced changes were minimized by valproate (figure 1b, 1c). these results demonstrate that treatment with valproate attenuates nitroglycerin - induced trigeminovascular activation in rats. the mtdna copy number was measured in the rat model with or without valproate treatment. compared with the control group, the mtdna copy number in the model group was decreased (figure 2a). a low dose of valproate significantly attenuated nitroglycerin - induced reduction of mtdna copy number, and a high dose of valproate preserved the mtdna copy number to nearly normal level (figure 2a). to investigate the effect of valproate on the biogenesis of mitochondria, the protein levels of pgc-1, tfam, and pparg were detected by western blot analysis. as shown in figure 2, the protein levels of pgc-1, tfam, and pparg were lower in the model group in comparison with the control group (figure 2b2d), but nitroglycerin - induced reduction in the expression of pgc-1, tfam, and pparg was inhibited by valproate. the level of atp in the spinal trigeminal nucleus was measured in the nitroglycerin - induced trigeminovascular activation rat models with or without valproate treatment. the atp level was lowered in the model group, indicating the dysfunction of mitochondrial energy metabolism. compared with the model group, a low dose of valproate elevated the atp level, which was further increased by a high dose of valproate (figure 3a). these results suggest that nitroglycerin - induced dysfunction of mitochondrial energy metabolism in the spinal trigeminal nucleus is alleviated by valproate. the mitochondrial membrane potential is crucial for energy metabolism in the mitochondria. in this study, as shown in figure 3b, almost all the jc-1 probes in the control group showed red fluorescence, which indicated a high mitochondrial membrane potential. in contrast, the jc-1 probes in the model group showed green fluorescence, indicating a low mitochondrial membrane potential in the nitroglycerin - induced trigeminovascular activation rat model. after treatment with a low dose of valproate, the jc-1 probes showed more red fluorescence and less green fluorescence, while the jc-1 probes in the model+vp - h group showed almost full red fluorescence (figure 3b). these results indicate that valproate treatment maintains the mitochondrial membrane potential in nitroglycerin - induced trigeminovascular activation. consistent with the observations by fluorescence microscopy, the mitochondrial membrane potential in the model group was significantly decreased compared with the control group. however, treatment with valproate prevented nitroglycerin - induced reduction of mitochondrial membrane potential (figure 3c, 3d). these results demonstrate that valproate preserves the mitochondrial membrane potential in the spinal trigeminal nucleus during nitroglycerin - induced trigeminovascular activation. bax and bcl-2 have close relationships with the opening of the mitochondrial permeability transition pore. here, the protein levels of bax and bcl-2 were detected by western blot. in the model group, the protein level of bax was higher than that in the control group (figure 4a), and the protein level of bcl-2 was lower than that in the control group (figure 4b). in contrast, treatment with valproate decreased the level of bax and increased the level of bcl-2 in the nitroglycerin - treated rats (figure 4a, 4b). these results provide molecular evidence for the hypothesis that valproate modulates the mitochondria energy metabolism in subjects with migraine. the activity of cytochrome c oxidase was also examined in our study. as shown in figure 4c, the cytochrome c oxidase activity in the model group was decreased significantly as compared with the control group. compared with the model group, valproate dose - dependently increased the activity of cytochrome c oxidase in the nitroglycerin - treated rats (figure 4c). consistent with the disrupted mitochondrial energy metabolism in nitroglycerin - treated rats, a significantly increased ros level was observed in the model group (figure 4d). treatment with valproate significantly attenuated nitroglycerin - induced ros elevation in the spinal trigeminal nucleus. after induction of trigeminovascular activation with nitroglycerin, the number of scratching behaviors was recorded. as shown in figure 1a, the number of scratching behaviors in the model group was significantly higher than that in the control group. compared with the model group, the number of scratching behaviors was decreased in the model group rats with valproate pre - treatment. consistent with the number of scratching behaviors, the 5-ht level was decreased and the no level was increased in the model group compared with the control group, and the nitroglycerin - induced changes were minimized by valproate (figure 1b, 1c). these results demonstrate that treatment with valproate attenuates nitroglycerin - induced trigeminovascular activation in rats. the mtdna copy number was measured in the rat model with or without valproate treatment. compared with the control group, the mtdna copy number in the model group was decreased (figure 2a). a low dose of valproate significantly attenuated nitroglycerin - induced reduction of mtdna copy number, and a high dose of valproate preserved the mtdna copy number to nearly normal level (figure 2a). to investigate the effect of valproate on the biogenesis of mitochondria, the protein levels of pgc-1, tfam, and pparg were detected by western blot analysis. as shown in figure 2, the protein levels of pgc-1, tfam, and pparg were lower in the model group in comparison with the control group (figure 2b2d), but nitroglycerin - induced reduction in the expression of pgc-1, tfam, and pparg was inhibited by valproate. the level of atp in the spinal trigeminal nucleus was measured in the nitroglycerin - induced trigeminovascular activation rat models with or without valproate treatment. the atp level was lowered in the model group, indicating the dysfunction of mitochondrial energy metabolism. compared with the model group, a low dose of valproate elevated the atp level, which was further increased by a high dose of valproate (figure 3a). these results suggest that nitroglycerin - induced dysfunction of mitochondrial energy metabolism in the spinal trigeminal nucleus is alleviated by valproate. the mitochondrial membrane potential is crucial for energy metabolism in the mitochondria. in this study, as shown in figure 3b, almost all the jc-1 probes in the control group showed red fluorescence, which indicated a high mitochondrial membrane potential. in contrast, the jc-1 probes in the model group showed green fluorescence, indicating a low mitochondrial membrane potential in the nitroglycerin - induced trigeminovascular activation rat model. after treatment with a low dose of valproate, the jc-1 probes showed more red fluorescence and less green fluorescence, while the jc-1 probes in the model+vp - h group showed almost full red fluorescence (figure 3b). these results indicate that valproate treatment maintains the mitochondrial membrane potential in nitroglycerin - induced trigeminovascular activation. consistent with the observations by fluorescence microscopy, the mitochondrial membrane potential in the model group was significantly decreased compared with the control group. however, treatment with valproate prevented nitroglycerin - induced reduction of mitochondrial membrane potential (figure 3c, 3d). these results demonstrate that valproate preserves the mitochondrial membrane potential in the spinal trigeminal nucleus during nitroglycerin - induced trigeminovascular activation. bax and bcl-2 have close relationships with the opening of the mitochondrial permeability transition pore. here, the protein levels of bax and bcl-2 were detected by western blot. in the model group, the protein level of bax was higher than that in the control group (figure 4a), and the protein level of bcl-2 was lower than that in the control group (figure 4b). in contrast, treatment with valproate decreased the level of bax and increased the level of bcl-2 in the nitroglycerin - treated rats (figure 4a, 4b). these results provide molecular evidence for the hypothesis that valproate modulates the mitochondria energy metabolism in subjects with migraine. as shown in figure 4c, the cytochrome c oxidase activity in the model group was decreased significantly as compared with the control group. compared with the model group, valproate dose - dependently increased the activity of cytochrome c oxidase in the nitroglycerin - treated rats (figure 4c). consistent with the disrupted mitochondrial energy metabolism in nitroglycerin - treated rats, a significantly increased ros level was observed in the model group (figure 4d). treatment with valproate significantly attenuated nitroglycerin - induced ros elevation in the spinal trigeminal nucleus. in the present study, we evaluated the effect of valproate on migraine in a rat model of nitroglycerin - induced trigeminovascular activation, and further investigated the underlying mechanism. valproate decreased the number of scratching behaviors and reduced the changes in 5-ht and no levels in our rat model of nitroglycerin - induced trigeminovascular activation. moreover, the mitochondrial biogenesis and energy metabolism, which was disrupted in nitroglycerin - treated rats, was stabilized by valproate. these results prompted us to hypothesize that valproate may attenuate migraine by preserving mitochondrial function. consistently, valproate has been reported to show a remission effect on migraine, and intravenous injection with valproate can rapidly abort headaches. similarly, other antiepileptic drugs, such as topiramate and divalproex, have also been demonstrated to be effective prophylactic treatments of migraine. mitochondria are crucial to mammalian cells because they are the major sites of atp production, and are also related to apoptosis regulation and ca homeostasis. dysfunction of mitochondria can lead to a variety of disorders, especially in organs consuming large amounts of energy. n - acetylaspartate (naa), which is produced exclusively in neuronal mitochondria, is reported to be reduced in migraine patients. recent reports also show that abnormal mitochondrial function leads to intracellular ca penetration, excessive ros production, and oxidative phosphorylation deficiency, which may ultimately cause energy failure in cells, and trigger migraine. in the present study, we showed that the mitochondrial biogenesis and the mitochondrial energy metabolism were impaired in a rat model of nitroglycerin - induced trigeminovascular activation. our results supportive the hypothesis that mitochondrial dysfunction is associated with the pathophysiology of migraine. in our study, the mtdna copy number was decreased in the nitroglycerin - induced trigeminovascular activation model, whereas treatment with valproate preserved the mtdna copy number in the spinal trigeminal nucleus. the protein levels of pgc-1, tfam, and pparg, which are closely associated with the biogenesis of mitochondria, were reduced in the rat model of nitroglycerin - induced trigeminovascular activation and were maintained by valproate. the changes in these 3 proteins provide additional evidence for our hypothesis that valproate prevents dysregulation of mitochondrial biogenesis. showed that valproate had positive effects on the maintenance of mtdna and mitochondrial biogenesis in polg - deficient fibroblasts. moreover, valproate also plays an anti - oxidative role and alleviates neuronal damages caused by migraine attacks through nf-b. the mitochondrial energy metabolism was disrupted in a rat model of nitroglycerin - induced trigeminovascular activation, and was rescued by valproate. these results suggest that the effect of valproate on migraine may be associated with its action on mitochondrial function.. showed that long - term treatment with valproate enhances mitochondrial function and protects against methamphetamine - induced mitochondrial damage. however, komulainen. reported that treatment with valproate inhibits mitochondrial respiration and leads to mitochondrial dysfunction, oxidative stress, and increased cell death of hepg2 cells, which was assumed to be attributed to the hepatotoxicity of valproate. interestingly, bachmann. also showed that a low dose of valproate enhances cellular respiration, whereas a high dose of valproate inhibits the respiration rate. thus, the contradictory results from bachmann s and komulainen s work may be due to the different doses used. therefore, further investigations are needed to address whether valproate has hepatotoxicity during the treatment of migraine, as well as to determine the optimal dosage of valproate for the treatment of migraine. the ratio of bax and bcl-2 is very important to the opening of the mitochondrial permeability transition pore, which also leads to the release of cytochrome c and the generation of ros. migraine attack triggers oxidative stress, resulting in increased production of ros. in our study, nitroglycerin - induced mitochondrial dysfunction was associated with abnormal levels of bax, bcl-2, cytochrome c oxidase, and ros, and these changes were diminished by valproate treatment. as bax, bcl-2, and ros are closely related to cell apoptosis, the abnormal levels of bax, bcl-2, and ros in our study suggest that migraine may also have a relationship with apoptosis of neurocytes, but this hypothesis needs to be verified in future studies. the protective effect of valproate against nitroglycerin - induced trigeminovascular activation was associated with valproate - mediated protection of mitochondrial biogenesis and function. our study suggests that valproate may attenuate migraine through the maintenance of mitochondrial function, and provides a possible mechanism underlying the effect of valproate on migraine. | backgroundmigraine is a chronic disease that interferes with life quality and work productivity. valproate shows protective effects against migraine, yet the underlying mechanisms are unclear. this study aimed to evaluate the potential effect of valproate on migraine using a rat model of nitroglycerin - induced trigeminovascular activation, as well as to explore the underlying mechanism.material/methodsintraperitoneal injection of nitroglycerin was conducted to induce trigeminovascular activation in rats. to explore the protective effect of valproate, a low dose (100 mg / kg) or a high dose (200 mg / kg) of valproate was intraperitoneally injected into rats, and then the levels of 5-hydroxytryptamine and nitric oxide in the peripheral blood were examined. the mtdna copy number and the protein levels of peroxisome proliferator - activated receptor- coactivator 1, mitochondrial transcription factor a, and peroxisome proliferator - activated receptor- in the spinal trigeminal nucleus were detected to evaluate the biogenesis of mitochondria. the mitochondrial energy metabolism was determined by the mitochondrial membrane potential and the levels of adenosine triphosphate, cytochrome c oxidase, and reactive oxygen species.resultsvalproate attenuated nitroglycerin - induced trigeminovascular activation in rats, with reduced scratching behavior and restored 5-hydroxytryptamine and nitric oxide levels. moreover, the mitochondrial energy metabolism and the biogenesis of mitochondria were preserved by valproate in nitroglycerin - treated rats.conclusionsthe protective effect of valproate against migraine may be achieved through the modulation of mitochondrial biogenesis and function. our study provides evidence for the potential use of valproate in the treatment of migraine. |
as korea also experiences the graying of society, awareness of prostate cancer has increased, and with the introduction of prostate - specific antigen (psa), prostate cancer can be detected and treated early. the sensitivity of psa to detect prostate cancer has been reported to be high. recently, as its measurement has become standardized, the number of patients undergoing prostate biopsy is rising rapidly. in the past recently, however, owing to the development of prostate ultrasonography, transrectal ultrasound - guided prostate biopsy has become the standard procedure. transrectal ultrasound - guided prostate biopsy is essential for the definite diagnosis of prostate cancer ; nonetheless, it induces pain in many cases. it has been reported that the pain is severe in approximately 19% to 25% of patients undergoing prostate biopsy [1 - 3 ]. in addition, many patients present with not only pain felt during the prostate biopsy but also pain felt during the insertion of the transrectal ultrasound probe. furthermore, it has been reported that approximately 20% of the patients do not wish to undergo prostate biopsy again unless the pain is reduced. therefore, numerous methods have been suggested to reduce the pain during transrectal ultrasound - guided prostate biopsy [4 - 17 ]. presently, to reduce the pain before prostate biopsy, the most widely applied method is the periprostatic nerve block method with 1% lidocaine. tramadol is used for the reduction of pain in many fields, and acetaminophen has been reported to augment the analgesic effects of tramadol. eutectic mixture of local anesthetics (emla) cream (2.5% lidocaine, 2.5% prilocaine) is a topical anesthetic agent that is frequently used in the dermatologic and obstetric fields. in this study, we compared with pain - relieving effect of acetaminophen and emla in addition to intravenous injection of tramadol with that of the conventional periprostatic nerve block method. this was a prospective, single - blinded randomized study performed in a tertiary urology center. the study subjects were selected from patients who visited the department of urology at our hospital during approximately 14 months from may 2009 to june 2010. the subjects were 430 patients who underwent transrectal ultrasound - guided prostate biopsy, and all biopsies were performed by a single urologist. at the time of selection of the subjects, patients with prostatitis, chronic pelvic pain, or anal diseases such as hemorrhoids, anal fissure, and anal fistula, the subjects were divided into the periprostatic nerve block group, in whom 1% lidocaine was injected (group 1) ; the oral acetaminophen 650 mg group (group 2) ; and the emla cream group (group 3). thirty minutes before prostate biopsy, 50 mg tramadol was injected intravenously in all groups of patients, and 5 g of emla cream was applied 30 minutes before prostate biopsy to the peri - anal area and rectum in group 3. emla cream is known to allow dermal anesthesia and is specially applied to prevent pain associated with superficial surgical procedures. emla can be used under occlusive dressing. in our case, however, because the affected areas were the peri - anal area and rectum, occlusive dressing could not be applied. regarding the number of prostate biopsy samples, 10 cores or 12 cores the transrectal ultrasound examinations were performed by using the general electric logiq400md ultrasound machine and a 6 mhz transducer. three hours after prostate biopsy, by a single - blind method, a third person evaluated the pain that was felt during the insertion of the transrectal ultrasound probe by using a visual analogue scale (vas) (fig. a score of 0 was defined as no pain, and 10 points was defined as the most severe intolerable pain. in addition, we surveyed whether the patients were willing to undergo another prostate biopsy in the future if required. after 3 days, the pain that developed during the biopsy and the presence of complications were assessed again in telephone interviews. for the statistical program, spss ver. 12.0 statistical analysis was performed with anova and pearson chi - square test, and p - values less than 0.05 were considered to be statistically significant. the mean age of the 430 patients was 66.2%9.7 years, the average psa was 10.4%13.8 ng / ml, the average prostate size was 42.9%21.0 ml, and the average number of biopsy cores was 10.4%0.8. the average pain score at the time of insertion of the ultrasound probe and the pain score at the time of biopsy were 4.12%2.20 and 3.90%1.78, respectively, and the percentage of patients who indicated that they would be willing to undergo rebiopsy if needed was 65.3% (281 of 430 patients). the pain scores at the time of insertion of the ultrasound probe and at the time of biopsy were similar for group 2 and group 3. however, they were significantly lower than the pain scores of group 1 (p<0.05) (table 2). similarly, the percentages of patients willing to undergo rebiopsy in group 2 and group 3 were 67.6% (107/158) and 71.4% (105/147), respectively, which was significantly higher than in group 1 (55.2% ; 69/125) (p<0.05). regarding side effects that developed after prostate biopsy, there was 1 case of acute prostatitis, 1 of vasovagal, and 5 of rectal bleeding (table 3). the patient who developed acute prostatitis in group 3 was discharged after intravenous injection of antibiotics for 2 days. the patient who developed vasovagal syncope in group 2 was stabilized by bed rest and hydration without any other special treatment. regarding the 5 cases of rectal bleeding, 1 patient was from group 1, 2 patients were from group 2, and 2 patients were from group 3. the bleeding in all cases was stopped within 30 minutes and no additional hospitalization or outpatient visits were required. similarly, in the telephone interview conducted 3 days after biopsy, it was found that no additional pain or other complications had developed. with the prolongation of the average life span, the incidence of prostate cancer has rapidly increased worldwide in recent years. in 2005, in america, the number of patients who experienced prostate biopsy increased such that more than 770,000 cases of transrectal ultrasound - guided prostate biopsy were performed. recent statistics indicate that, even if cancer is not detected at the initial biopsy, it is detected at rebiopsy in 21% to 29% cases [20 - 22 ], and thus the importance of rebiopsy has been emphasized. the greatest factor contributing to patients??refusal to undergo rebiopsy may be the pain felt at the time of the initial biopsy. redelmeier reported that when colonoscopy is performed repeatedly on patients who have experienced colonoscopy once, their pain score is higher than that of patients undergoing colonoscopy for the first time. therefore, from the aspect of reducing the discomfort of patients, pain reduction is important and it is thought to play a role in the willingness to undergo rebiopsy if needed. in our study, not only the pain at the time of the prostate biopsy but also the willingness regarding rebiopsy were studied. in addition, similar to colonoscopy, pain scores may be increased due to previous experiences ; thus, in our study, patients who experienced prostate biopsy in the past were excluded. transrectal ultrasonography was first applied to examine the prostate in 1963 by takahashi and ouchi. in 1989, hodge performed transrectal ultrasound - guided 6-core prostate biopsy. afterward, this method was used as the standard method for the diagnosis of prostate cancer. to raise the rate of diagnosis, recently, efforts have been made to reduce the pain of patients, and bleeding, infection, and other complications caused by biopsy have been considered. although numerous studies on the methods used to reduce pain have been conducted in korea as well as in other countries, to date, standard procedures have not been established. currently, the most widely used method for pain reduction is the nerve block method using 1% lidocaine before biopsy. additional methods are the application of lidocaine gel to the rectum and the periprostate area [5 - 10 ], injection of diclofenac or ketorolac, midazolam administration, inhalation anesthesia using n2o, and intravenous anesthesia using propofol. from the aspect of convenience and effectiveness, however, whether to consider these as standard procedures is controversial. irani have reported that the application of lidocaine gel to the rectum and the peri - prostate area was effective ; however, a control group was not included in that study. desgrandchamps compared a group in which 2% lidocaine was applied to the rectum with a control group in which ultrasound gel was applied and reported that the application of lidocaine to the rectum did not improve the patients??pain at the time of biopsy. in korea, song showed that the pain level of a group in whom lidocaine was applied to the rectum was not significantly different from that of a control group in whom saline was injected into the periprostatic area. although numerous studies have been performed on the application of lidocaine gel to the rectum and the periprostatic area, concurrent effects have not been reported [5 - 8,10 ]. the anesthetic effect of the injection of diclofenac or ketorolac alone is relatively insufficient, and thus cases without sufficient reduction of pain are frequently seen. sedatives such as midazolam may induce severe side effects such as delirium, confusion, amnesia, and respiratory failure, and elderly males are more vulnerable to the development of these complications. because many people have an aversion to general anesthesia, inhalation anesthesia with n2o and intravenous anesthesia with propofol are difficult to perform in reality, and these methods are also cost - ineffective. the purpose of this study was to assess the effect of the oral administration of 650 mg acetaminophen and emla cream in addition to intravenous injection of tramadol and to compare their effects with the conventional method used to reduce pain. the vas, a method that is used in many fields to assess pain, was used for the comparison. the vas can be used regardless of age, language, and race, and because it is numerically assessed, it is a good method for comparing pain statistically. the results of our study showed that in comparison with the conventional periprostatic nerve block method, the pain - relieving effect of the oral administration of 650 mg acetaminophen and the application of emla cream was excellent, and no side effects induced by the drugs were detected. in particular, the advantage of the oral administration of 650 mg acetaminophen and the topical application of emla cream is that the pain caused by use of the needle for injection of the 1% lidocaine does not occur. when the periprostatic nerve block procedure is performed, the number of needle injections is increased in addition to conventional biopsy by more than two, which may be associated with complications such as prostatitis and bleeding. however, in our study, the complication rate of group 1, in which nerve block was performed, was not significantly different from that of groups 2 and 3, in which nerve block was not performed. these findings agree with the study reported by obek. in the evaluation of vas pain scores, scores of 1 to 3 are considered mild, 4 to 6 moderate, and 7 severe. in this study, the ratios of the patients presenting with severe pain (7) at the time of probe insertion were 36% (group1), 12.0% (group 2), and 6.1% (group 3). the ratios at the time of biopsy were 19.2% (group 1), 3.8% (group 2), and 1.7% (group 3). the anxiety and pain caused by prostate biopsy are associated with the anal pain induced by the ultrasonography probe insertion and the pain induced by the needles at the time of biopsy. however, the anal pain during probe insertion is known to cause more pain than the biopsy itself. in our study, similarly, comparable results were observed, and in comparison with group 1, the anal pain that developed at the time of the insertion of the ultrasonography probe in groups 2 and 3 was statistically significantly reduced. the advantages of our study were that the biopsies were performed by a single urologist, and thus our study is superior to other studies in which biopsies were performed by several urologists. in addition, the oral administration of acetaminophen before prostate biopsy or the use of emla cream are simple, side effects were rare, the pain that developed at the time the ultrasonography probes passed through the anus and the pain that developed at the time of biopsy could be reduced, and willingness to undergo rebiopsy was increased. regarding selecting a preferable method, patients ' kidney and liver functions as well as their perirectal skin condition should be taken under consideration, because acetaminophen can cause hepatitis or renal insufficiency, although very rarely, and emla should not be used with open wounds. a potential imitation of our study is that the vas is a very subjective index. the absence of a control group with tramadol is also a limitation, because tramadol may have achieved significant relief of pain. according to the results of our study, oral administration of 650 mg acetaminophen and topical application of emla cream, in addition of intravenous tramadol, reduce pain and are both technically easy, noninvasive, and safe. moreover, these methods were more effective for pain relief than was the conventional periprostatic nerve block method. therefore, they are thought to be useful methods of relieving pain during prostate biopsy. | purposetransrectal ultrasound - guided prostate biopsy is the procedure of choice for diagnosing prostate cancer. we compared with pain - relieving effect of acetaminophen, a known drug for enhancing the pain - relieving effect of tramadol, and eutectic mixture of local anesthetics (emla), a local anesthetic agent, with that of the conventional periprostatic nerve block method.materials and methodsthis was a prospective, randomized, single - blinded study. a total of 430 patients were randomly assigned to three groups. group 1 received a periprostatic nerve block with 1% lidocaine, group 2 received acetaminophen 650 mg, and group 3 received emla cream for pain control. all patients were given 50 mg of tramadol intravenously 30 minutes before the procedure. at 3 hours after completion of the procedure, the patients were asked to grade their pain on a horizontal visual analogue scale (vas). the patients were also asked whether they were willing to undergo future biopsy if required.resultsthere were no significant differences between the three groups in terms of age, prostate - specific antigen, prostate size, or numbers of biopsy cores. the pain scores for groups 2 and group 3, which were 3.471.92 and 3.501.36, respectively, were similar and were significantly lower than that of group 1, which was 5.242.07.conclusionsacetaminophen and emla cream with intravenous injection of tramadol are safe, easy, and effective methods of controlling pain during the procedure. these methods were more effective for pain relief than was the conventional periprostatic nerve block method. |
approved study included consecutive patients who underwent ventral hernia repair with components separation with padm reinforcement performed by the author at the university of pittsburgh medical center (pittsburgh, pennsylvania) and butler memorial hospital (butler, pennsylvania). surgeries were performed between august 2008 and january 2012, with follow - up data available through february 2013. information on patient demographics, comorbidities, relevant medical and surgical history, presence of previously placed mesh, and length of surgical incision were recorded. prior to surgery, smokers were advised regarding smoking cessation, and all patients received prophylactic antibiotics. ventral hernia repair, including components separation with bilateral dissection of the external oblique to the inferior portion of the pectoralis major muscle (fig. 1), removal (if possible) of any previously placed mesh, and placement of padm was performed in all patients according to the author 's usual technique. for midline closure, 1 prolene monofilament nonabsorbable (ethicon, inc, somerville, new jersey), or no. 1 surgipro monofilament nonabsorbable (covidien, mansfield, massachusetts) sutures were used. padm was overlaid in a medial position across the anterior side of the rectus abdominis and sutured into place with interrupted maxon no. two size-19 french blake drains (ethicon) were placed in all patients and remained in place until drainage was 30 kg / m, 60% ], and most (64%) were classified as having vhwg grade 2 or grade 3 risk for postoperative complications at the surgical site. other comorbidities that were present in 5% of the study population included diabetes (n = 14, 30%), history of cancer (n = 6, 13%), chronic obstructive pulmonary disease (n = 4, 9%), and history of deep - vein thrombosis (n = 3, 6%). patient demographics and characteristics twenty - three patients (49%) had undergone previous ventral herniorrhaphy. the number of previous herniorrhaphies in the total study sample ranged from 0 to 11 (median, 0) ; the majority of patients (79%) had 1 previous repair. the mean (sd) length of surgical incision was 26 (9) cm. primary fascial closure was achieved, and padm was successfully placed in all 47 patients. herniorrhaphy was performed in the setting of infected previously placed mesh in 5 patients (11%), and the infected mesh was removed during surgery in all of these patients. the mean (sd) length of hospital stay was 8 (6) days (median, 6 days ; range, 229 days). patients were followed for a mean (sd) duration 31 (12) months (median, 34 months ; range, 1354 months). overall, 12 patients experienced a total of 14 postoperative complications (3 hernia recurrences and 11 other complications ; table 2). of the 3 patients (6%) who experienced hernia recurrence during the follow - up period, 2 had recurrences at 18 months postsurgery and 1 had recurrence at 7 months postsurgery. the patient with recurrence at 7 months was an 85-year - old, nonobese (bmi, 25 kg / m) man who had 2 previous herniorrhaphies. he had no other relevant comorbidities and was classified as having vhwg grade 1 risk at the time of the most recent surgery. one patient who had a hernia recurrence at 18 months postsurgery was a 50-year - old, morbidly obese (bmi, 46 he had vhwg grade 2 risk for postsurgical complications and no other relevant comorbidities at the time of surgery. the other patient who experienced hernia recurrence at 18 months after surgery was a 75-year - old obese (bmi, 36 kg / m) woman who had a history of 11 previous ventral hernia repair procedures. she had a previously placed infected mesh removed during her most recent surgery (vhwg grade 4 risk). summary of postoperative complications nine of the 47 (19%) patients experienced 11 other postoperative complications, including deep - vein thrombosis (n = 4), seroma (n = 3), wound infection (n = 2), and bleeding (n = 2). in this cohort of patients, ventral hernia repair with use of components separation and non cross - linked padm resulted in low rates of postsurgical complications. overall, 75% of patients did not experience any postsurgical complications, and only 3 experienced a recurrent hernia during a mean follow - up of approximately 2.5 years. these observations are particularly encouraging given that about half of the patients included in the study had undergone one or more previous ventral hernia repairs. prior abdominal surgery is a known risk factor for hernia recurrence, and this risk increases with each subsequent repair. the risk of postsurgical complications after awr with prosthetic mesh placement can be impacted by numerous factors, including patient comorbidities, the complexity of the patient 's condition at the time of surgery, the surgeon 's techniques for prosthetic mesh placement, the specific physical and/or chemical properties of the individual matrix or mesh, and the time elapsing since hernia repair. reported rates of recurrence across studies of synthetic mesh in awr range from 4% to 32%, with a mean of approximately 19% across studies. reported recurrence rates following placement of biologic tissue matrix range between 0% and 44%, with a mean of approximately 12% across studies, compared with the recurrence rate of 6% observed in the current study. there have been several previous reports of results from prospective and retrospective studies of padm use in complex awr. it is not surprising that incidences of postsurgical complications observed in the current study were lower than complication rates in previous studies involving populations that largely comprised patients with potentially contaminated (vhwg grade 3) or infected (vhwg grade 4) surgical sites. one previous study included a population largely comprising patients with vhwg grade 2 risk for postsurgical complications, as in the current study. patel and colleagues retrospectively assessed postsurgical outcomes following awr with components separation and padm in a cohort of 41 patients ; of whom, 33 (81%) were classified as having vhwg grade 2 risk for postsurgical complications. the authors observed incidences of seroma, wound infection, and hernia recurrence of 7%, 2%, and 0%, respectively, at a mean follow - up of 16 months. in the current study, the incidences of seroma, wound infection, and hernia recurrence were 6%, 4%, and 6%, respectively, in a population that had 62% of patients classified as vhwg grade 2 risk followed for a mean of 31 months. the high incidence of postoperative deep - vein thrombosis (9%) in the current study may be explained by patient histories. of the 4 patients who experienced deep - vein thrombosis, 1 was a cancer patient who was also a smoker with chronic obstructive pulmonary disease, and he had a previously placed infected mesh removed during the current surgery (i.e., classified as vhwg grade 4 risk). the other 3 patients with deep - vein thrombosis were classified as having grade 2 risk, though all 3 were smokers and 2 were obese. interpretation of the results of this study is limited by its retrospective design ; the fact that the study included a heterogeneous group of patients undergoing surgery at one health system by a single surgeon ; the lack of a control group or comparator ; and its limited duration of follow - up. it will be important to continue follow - up on these patients to evaluate long - term outcomes. the use of non cross - linked padm for reinforcement following components separation in complex ventral hernia repair resulted in low rates of postoperative complications and hernia recurrence in this patient cohort. continued follow - up of these patients will be key for evaluating the long - term success of this approach for ventral hernia repair. | repair of complex ventral hernias frequently results in postoperative complications. this study assessed postoperative outcomes in a consecutive cohort of patients with ventral hernias who underwent herniorrhaphy using components separation techniques and reinforcement with non cross - linked intact porcine - derived acellular dermal matrix (padm) performed by a single surgeon between 2008 and 2012. postoperative outcomes of interest included incidence of seroma, wound infection, deep - vein thrombosis, bleeding, and hernia recurrence determined via clinical examination. of the 47 patients included in the study, 25% were classified as having ventral hernia working group grade 1 risk, 62% as grade 2, 2% as grade 3, and 11% as grade 4 ; 49% had undergone previous ventral hernia repair. during a mean follow - up of 31 months, 3 patients experienced hernia recurrence, and 9 experienced other postoperative complications : 4 (9%) experienced deep - vein thrombosis ; 3 (6%), seroma ; 2 (4%), wound infection ; and 2 (4%), bleeding. the use of padm reinforcement following components separation resulted in low rates of postoperative complications and hernia recurrence in this cohort of patients undergoing ventral hernia repair. |
alzheimer s disease (ad) is the most common cause of senile dementia.1 it was first described by alois alzheimer in 1906.2 in 2012, there were 36 million people worldwide with ad. it is predicted to affect more than 115 million people globally by 2050.3 it is a progressive, neurodegenerative disorder that is usually diagnosed in people over 65 years of age.4 donepezil is a reversible acetylcholinesterase inhibitor that has been approved for use for ad. it is believed to inhibit the breakdown of the neurotransmitter acetylcholine and compensate for the deficiency of acetylcholine in brain.5,6 in previous clinical trials, it has been shown to improve cognitive function in patients for a wide range of ad severity, from very mild to moderate - to - severe.711 the most common adverse events (aes) with donepezil, as well as with other cholinesterase inhibitors, are nausea, vomiting, diarrhea, and dizziness, all of which are symptoms linked to cholinergic hyperstimulation.12,13 these effects are dose - related and largely depend on the plasma fluctuations.14 when donepezil is orally administered, it is well absorbed and reaches peak plasma concentrations (cmax) in 34 hours.15 the plasma concentration of donepezil then decreases until the next dose is administered.16 by reducing cmax and slowing the time that it takes to reach cmax (tmax), the potential for these aes may be attenuated. the advantages of transdermal drug delivery for ad have already been reported : reduced dosing frequency, improved bioavailability, reduced side effects, and improved patient compliance due to simple application.1719 for this reason, rivastigmine, one of the acetylcholinesterase inhibitors, has already been developed as a transdermal patch.16,20,21 the transdermal donepezil patch was also developed for the advantage of providing smooth and steady delivery of donepezil through the skin ; a transdermal patch would decrease cmax and lengthen tmax while maintaining drug exposure.17 according to in vivo studies, when transdermal donepezil (40 mg / kg, 2.14 cm) was applied to the abdominal skin of male sprague - dawley rats, the cmax at steady state (52.2 ng / ml) was maintained for 48 hours with the donepezil formulation using oleic acid.22 the company icure pharmaceutical lncorporated (anseong, gyeonggi - do, republic of korea), which manufactures the donepezil patch that was used in this study, also conducted in vivo studies to evaluate pharmacokinetics. when a single dose of 5 mg / kg oral solution was administered to hairless wistar yagi rats, the cmax was 41.4 ng / ml with a tmax of 1 hour. when 8.75 mg/2.5 cm, 17.5 mg/5 cm, and 35 mg/10 cm donepezil patches were applied to hairless wistar yagi rats, the cmax values were dose - proportional (36.5 ng / ml, 64.4 ng / ml, and 129.1 ng / ml, respectively) with tmax values of 2436 hours.23 the aim of this randomized, single - blind, placebo - controlled, single - dose, dose - escalation study was to investigate the tolerability and the pharmacokinetics of the novel donepezil patch in healthy male subjects. each healthy male volunteer who was 2045 years of age and had a body mass index (bmi) of 2026 kg / m was eligible for this study. volunteers were considered to be in good health on the basis of these criteria, which were assessed within the 4 weeks prior to the first administration of the study drug : medical history ; physical examinations ; vital sign measurements (blood pressure, heart rate, and body temperature) ; 12-lead electrocardiograms (ecgs) ; clinical laboratory tests (hematology, blood chemistry, and urinalysis) ; serology (hepatitis b surface antigen, hepatitis c virus antibody, and hiv antigen / antibody) ; and urine drug screening (amphetamine, methamphetamine, barbiturate, cocaine, opiate, benzodiazepine, cannabinoid, and methadone). each subject with a known allergy or hypersensitivity to donepezil or with a history of drug abuse the study protocol was approved by the ministry of food and drug safety (mfds) and the institutional review board of the asan medical center (amc), seoul, republic of korea. the study was conducted at the clinical trial center of the amc from may 2013 to september 2013. all subjects provided written informed consent before screening tests, and this study was conducted in accordance with the declaration of helsinki and international conference of harmonization (ich) guidelines for good clinical practice. this study was designed as a randomized, single - blind, placebo controlled, dose - escalation study. in this study, a 3.5 mg / cm donepezil patch was applied as a single dose of 43.75 mg/12.5 cm, 87.5 mg/25 cm, or 175 mg/50 cm. there were 12 subjects per group, nine of whom were given active patches and three of whom were given placebos. the subjects were admitted to the hospital on the day before drug administration. on the morning of day 1, each subject received a single application to the upper back with a patch - on period of 72 hours. all subjects were discharged on day 5 (24 hours after patch removal), and they revisited the hospital on days 6, 7, 8, 10, 12, and 14 to assess the tolerability and the pharmacokinetics of donepezil. follow - up visits were performed 1822 days after the patch application. for pharmacokinetic analysis, sequential blood samples were collected prior to and at 4, 8, 12, 24, 48, 70, 72, 74, 76, 80, 96, 120, 144, 168, 216, 264, and 312 hours after patch administration. all blood samples for the determination of donepezil concentrations were drawn into heparinized tubes and separated by centrifugation at 1,800 g for 8 minutes at 4c and stored at 70c until analysis. the adhesive properties of each patch were evaluated every 12 hours (within approximately 30 minutes) from time 0 (the time of adhesion) through 72 hours (before patch removal) after the application of donepezil patch. the adhesiveness of patch was graded according to the criteria in table 1.24 tolerability was assessed throughout the study by using vital sign measurements ; ecgs ; clinical laboratory tests (hematology, blood chemistry, and urinalysis) ; physical examinations ; and monitoring of aes. aes were recorded in terms of symptoms and signs, duration, intensity, relationship to the study drug, action taken, outcome, and seriousness. assessment of skin irritation was performed immediately after the removal of the patch (72 hours) as well as 1, 12, and 24 hours after patch removal (at 73, 84, and 96 hours after patch application, respectively) by using a skin irritation scoring system (table 1).24 after the subject was discharged, the skin irritation score was assessed at every outpatient visit until that subject experienced an irritation score of 0. plasma concentrations of donepezil were determined by using validated high performance liquid chromatography (hplc) coupled with tandem mass spectrometry. the sample extracts were analyzed by using hplc (nonospace si-2 3133 ; shiseido, tokyo, japan) and an unison uk - c18 column (3.0 m, 50 mm 2.0 mm ; imtakt, kyoto, japan) with a mobile phase consisting of ammonium formate with 0.1% formic acid and acetonitrile with 0.1% formic acid (40:60, v / v). the ms system (api-4000 ; ab sciex, framingham, ma, usa) was operated in positive ion electrospray mode with multiple reaction monitoring. for donepezil and the internal standard, the precursor - to - production reactions that were monitored were mass - to - charge ratios (m / z), 380.391.1 and 256.2167.1, respectively. calibration curves covered the concentration range of 0.180 ng / ml (r>0.99). by using this assay, interday accuracy ranged from 96.27% to 105.98%, and interday precision, expressed as percent coefficient of variation (% cv), ranged from 0.7% to 4.3%. in addition, intraday accuracy and precision (% cv) ranged from 97.23% to 104.92% and from 1.4% to 5.3%, respectively. time profiles of donepezil in the subjects were analyzed by using a noncompartmental method and winnonlin 6.1 (pharsight corporation, princeton, nj, usa). the terminal elimination rate constant (z) was estimated by linear regression of the terminal log - linear portion of the plasma concentration time curves. concentration curve (auc) from time 0 to the last measurable time (auclast) was calculated by the trapezoidal rule, and the auc extrapolated to infinity (aucinf) was obtained as follows : aucinf = auclast+clast/z(1)for which clast is the last quantifiable concentration. the t1/2 was calculated for each participant as follows : t1/2=ln(2)/z(2) all statistical analyses were performed by using sas 9.3 (sas korea, seoul, republic of korea) and phoenix winnonlin 6.1 (pharsight corporation). each healthy male volunteer who was 2045 years of age and had a body mass index (bmi) of 2026 kg / m was eligible for this study. volunteers were considered to be in good health on the basis of these criteria, which were assessed within the 4 weeks prior to the first administration of the study drug : medical history ; physical examinations ; vital sign measurements (blood pressure, heart rate, and body temperature) ; 12-lead electrocardiograms (ecgs) ; clinical laboratory tests (hematology, blood chemistry, and urinalysis) ; serology (hepatitis b surface antigen, hepatitis c virus antibody, and hiv antigen / antibody) ; and urine drug screening (amphetamine, methamphetamine, barbiturate, cocaine, opiate, benzodiazepine, cannabinoid, and methadone). each subject with a known allergy or hypersensitivity to donepezil or with a history of drug abuse the study protocol was approved by the ministry of food and drug safety (mfds) and the institutional review board of the asan medical center (amc), seoul, republic of korea. the study was conducted at the clinical trial center of the amc from may 2013 to september 2013. all subjects provided written informed consent before screening tests, and this study was conducted in accordance with the declaration of helsinki and international conference of harmonization (ich) guidelines for good clinical practice. this study was designed as a randomized, single - blind, placebo controlled, dose - escalation study. in this study, a 3.5 mg / cm donepezil patch was applied as a single dose of 43.75 mg/12.5 cm, 87.5 mg/25 cm, or 175 mg/50 cm. there were 12 subjects per group, nine of whom were given active patches and three of whom were given placebos. the subjects were admitted to the hospital on the day before drug administration. on the morning of day 1, each subject received a single application to the upper back with a patch - on period of 72 hours. all subjects were discharged on day 5 (24 hours after patch removal), and they revisited the hospital on days 6, 7, 8, 10, 12, and 14 to assess the tolerability and the pharmacokinetics of donepezil. follow - up visits were performed 1822 days after the patch application. for pharmacokinetic analysis, sequential blood samples were collected prior to and at 4, 8, 12, 24, 48, 70, 72, 74, 76, 80, 96, 120, 144, 168, 216, 264, and 312 hours after patch administration. all blood samples for the determination of donepezil concentrations were drawn into heparinized tubes and separated by centrifugation at 1,800 g for 8 minutes at 4c and stored at 70c until analysis. the adhesive properties of each patch were evaluated every 12 hours (within approximately 30 minutes) from time 0 (the time of adhesion) through 72 hours (before patch removal) after the application of donepezil patch. tolerability was assessed throughout the study by using vital sign measurements ; ecgs ; clinical laboratory tests (hematology, blood chemistry, and urinalysis) ; physical examinations ; and monitoring of aes. aes were recorded in terms of symptoms and signs, duration, intensity, relationship to the study drug, action taken, outcome, and seriousness. assessment of skin irritation was performed immediately after the removal of the patch (72 hours) as well as 1, 12, and 24 hours after patch removal (at 73, 84, and 96 hours after patch application, respectively) by using a skin irritation scoring system (table 1).24 after the subject was discharged, the skin irritation score was assessed at every outpatient visit until that subject experienced an irritation score of 0. plasma concentrations of donepezil were determined by using validated high performance liquid chromatography (hplc) coupled with tandem mass spectrometry. the sample extracts were analyzed by using hplc (nonospace si-2 3133 ; shiseido, tokyo, japan) and an unison uk - c18 column (3.0 m, 50 mm 2.0 mm ; imtakt, kyoto, japan) with a mobile phase consisting of ammonium formate with 0.1% formic acid and acetonitrile with 0.1% formic acid (40:60, v / v). the ms system (api-4000 ; ab sciex, framingham, ma, usa) was operated in positive ion electrospray mode with multiple reaction monitoring. for donepezil and the internal standard, the precursor - to - production reactions that were monitored were mass - to - charge ratios (m / z), 380.391.1 and 256.2167.1, respectively. calibration curves covered the concentration range of 0.180 ng / ml (r>0.99). by using this assay, interday accuracy ranged from 96.27% to 105.98%, and interday precision, expressed as percent coefficient of variation (% cv), ranged from 0.7% to 4.3%. in addition, intraday accuracy and precision (% cv) ranged from 97.23% to 104.92% and from 1.4% to 5.3%, respectively. the plasma concentration time profiles of donepezil in the subjects were analyzed by using a noncompartmental method and winnonlin 6.1 (pharsight corporation, princeton, nj, usa). the terminal elimination rate constant (z) was estimated by linear regression of the terminal log - linear portion of the plasma concentration time curves. concentration curve (auc) from time 0 to the last measurable time (auclast) was calculated by the trapezoidal rule, and the auc extrapolated to infinity (aucinf) was obtained as follows : aucinf = auclast+clast/z(1)for which clast is the last quantifiable concentration. the t1/2 was calculated for each participant as follows : t1/2=ln(2)/z(2) all statistical analyses were performed by using sas 9.3 (sas korea, seoul, republic of korea) and phoenix winnonlin 6.1 (pharsight corporation). a total of 36 healthy korean volunteers were enrolled, and 36 subjects were administered the study drugs and completed the study. expressed as mean standard deviation, the mean characteristics of the study participants were as follows : the mean age was 27.654.54 years ; the mean weight was 67.067.76 kg ; and the mean height was 173.794.87 cm. the mean plasma concentration after the application of the donepezil patch, serum donepezil concentration increased slowly and peaked between ~7476 hours (~24 hours after patch removal) and declined with a t1/2 of ~63.7794.07 hours (table 2). in this study, the dose - normalized cmax and aucinf values were not statistically significant (p=0.5986 and p=0.3392, respectively). after patch application, the cmax and aucinf increased in a dose - proportional manner (figure 2). only one subject reported that the patch detached ; this happened more than 61 hours after patch application (table 3). the values for average donepezil residue (residual dose / loading dose 100 [% ]) in the patch 72 hours after application were as follows : 81.1%3.2% for the 43.75 mg/12.5 cm group, 80.4%4.4% for the 87.5 mg/25 cm group, and 78.4%2.5% for the 175 mg/50 cm group. included in the tolerability analysis were 36 subjects, all of whom applied donepezil patch. eleven subjects experienced a total of 14 aes, among which ten events in seven subjects were considered possibly related to the study drug (table 4). all aes were mild except for one case of hypertriglyceridemia in the 43.75 mg/12.5 cm group. an increase in triglycerides (1,318 mg / dl) without any symptoms was observed at the follow - up visit, and the decreased level was checked on subsequent visit. two application - site aes included skin discoloration and papules ; both were resolved without sequelae. likewise, there were no clinically significant abnormalities in vital signs, physical examinations, or electrocardiograms. the distributions of individual skin irritation scores after patch removal are shown in figure 3. immediately after patch removal (72 hours after application), most of the subjects experienced irritation scores of 1 (minimal erythema). all subjects experienced irritation scores of 0 (no evidence of irritation) by the day 12 outpatient visit (approximately 264 hours after patch application). irritation scores of 4, 5, 6, or 7 were not observed during the entire study. a total of 36 healthy korean volunteers were enrolled, and 36 subjects were administered the study drugs and completed the study. expressed as mean standard deviation, the mean characteristics of the study participants were as follows : the mean age was 27.654.54 years ; the mean weight was 67.067.76 kg ; and the mean height was 173.794.87 cm. the mean plasma concentration time profiles of donepezil are shown in figure 1. after the application of the donepezil patch, serum donepezil concentration increased slowly and peaked between ~7476 hours (~24 hours after patch removal) and declined with a t1/2 of ~63.7794.07 hours (table 2). in this study, the dose - normalized cmax and aucinf values were not statistically significant (p=0.5986 and p=0.3392, respectively). after patch application, the cmax and aucinf increased in a dose - proportional manner (figure 2). only one subject reported that the patch detached ; this happened more than 61 hours after patch application (table 3). the values for average donepezil residue (residual dose / loading dose 100 [% ]) in the patch 72 hours after application were as follows : 81.1%3.2% for the 43.75 mg/12.5 cm group, 80.4%4.4% for the 87.5 mg/25 cm group, and 78.4%2.5% for the 175 mg/50 cm group. included in the tolerability analysis were 36 subjects, all of whom applied donepezil patch. eleven subjects experienced a total of 14 aes, among which ten events in seven subjects were considered all aes were mild except for one case of hypertriglyceridemia in the 43.75 mg/12.5 cm group. an increase in triglycerides (1,318 mg / dl) without any symptoms was observed at the follow - up visit, and the decreased level was checked on subsequent visit. two application - site aes included skin discoloration and papules ; both were resolved without sequelae. likewise, there were no clinically significant abnormalities in vital signs, physical examinations, or electrocardiograms. the distributions of individual skin irritation scores after patch removal are shown in figure 3. immediately after patch removal (72 hours after application), all subjects experienced irritation scores of 0 (no evidence of irritation) by the day 12 outpatient visit (approximately 264 hours after patch application). irritation scores of 4, 5, 6, or 7 were not observed during the entire study. to our knowledge, this is the first published study to investigate the tolerability and pharmacokinetics of the donepezil patch in healthy subjects. after application, the donepezil patch provided a smooth and sustained plasma concentration time profile over the entire patch - on period of 72 hours. for the highest dose of donepezil (175 mg/50 cm) administered in this study, about 20% of the dose (approximately 35 mg) was released from the patch over the 72-hour application. as per the clinical pharmacology and biopharmaceutics review, the pharmacokinetic profile of 10 mg single - dose oral donepezil was reported to produce an aucinf of 885.30249.10 ng / ml and a cmax of 20.905.00 ng / ml.25 systemic exposure (aucinf) after a 72-hour application of 175 mg/50 cm was about three times higher than after the single dose of a 10 mg oral tablet, while the cmax with the patch was similar to the cmax with a 10 mg dose of oral donepezil. thus, this transdermal dose (about 35 mg/72 hours) is expected to produce exposure (auc) similar to 3 days of 10 mg oral donepezil but with a lower cmax. in the 43.75 mg/12.5 cm group, the % cv of aucinf was larger than in the other treatment groups (58.6% in the 43.75 mg/12.5 cm group, 24.5% in the 87.5 mg/25 cm group, and 32.2% in the 175 mg/50 cm group). of the nine subjects in the group, two showed lower clearances (28.1 and 28.7 l / hour) than average (72.3 l / hour), so the aucinf of each of these subjects was higher (1556.5 ngh / ml and 1526.8 ngh / ml, respectively) than average aucinf (808.5 ngh / ml). although we did not evaluate the different genotypes, the difference between cyp2d6 could have been one of the reasons for the large interindividual variability. in a recent population pharmacokinetic study in which donepezil clearance was evaluated in cyp2d6 genotypes, cyp2d6-poor metabolizers demonstrated a 32% lower clearance than did cyp2d6-extensive metabolizers.26 the disadvantages of transdermal delivery include skin irritation and imperfect adhesion to the skin.19 in this study, the results for skin irritation indicate that the skin reactions to the study drug were mild. the highest score was 3 (erythema and papules) ; this was seen in two subjects, and the condition was resolved to 0 (no evidence of irritation) within 8 days. except for one subject, the individual adhesion scores ranged between 0 (90% adherence) and 2 (adherence of 50% to < 75%) for 72 hours. first, these results were obtained from healthy male subjects ; the tolerability and pharmacokinetics of donepezil patch may differ in female or elderly ad patients. second, donepezil accumulated in plasma by four to seven - fold until the steady state ; further evaluation and comparison of the steady - state pharmacokinetics of the donepezil patch is needed.27 on the basis of the findings of this study, the investigation of multiple doses in healthy volunteers or elderly ad patients may be helpful to evaluate steady - state pharmacokinetics and to prove the optimal way to treat ad with donepezil. this study represents the first assessment of a single - dose donepezil patch in human subjects. | backgrounddonepezil is an acetylcholinesterase inhibitor indicated for alzheimer s disease. the aim of this randomized, single - blind, placebo - controlled, single - dose, dose - escalation study was to investigate the safety, tolerability, and pharmacokinetics of the donepezil patch in healthy male subjects.methodseach healthy male subject received a single transdermal donepezil patch (72 hours patch - on periods) of 43.75 mg/12.5 cm2, 87.5 mg/25 cm2, or 175 mg/50 cm2. serial blood samples were collected up to 312 hours after patch application. the plasma concentrations of donepezil were determined by using a validated liquid chromatography tandem mass spectrometry method. pharmacokinetic parameters were obtained by noncompartmental analysis. tolerability of the patches and performance of the patches (adhesion, skin irritation, residual donepezil content in the patch) were assessed throughout the study.resultsthe study was completed by 36 healthy subjects. after patch application, the maximal plasma donepezil concentration (cmax) and the area under the curve (auc) increased in a dose - proportional manner. median time to cmax was ~7476 hours (~24 hours after patch removal), and mean t1/2 was ~63.7793.07 hours. the average donepezil residue in the patch after 72 hours was ~73.9%86.7% of the loading dose. there were neither serious adverse events nor adverse events that lead to discontinuation. skin adhesion of the patch was good in 97.2% of the subjects. all skin irritations after patch removal were mild and were resolved during the study period.conclusionthe donepezil patch appeared to be generally well tolerated and adhesive. pharmacokinetic analysis of the donepezil patch demonstrated linear kinetics. |
dendritic cells (dc) are a subpopulation of leukocytes specialized in the capture and process of antigens and its presentation to t lymphocytes. in their immature state, they are located in peripheral tissues acting as sentinels. tissue residing dc form a close network, optimally positioned to sense invading pathogens. the antigens taken up by dc in the periphery are efficiently transported to t cell areas of local lymph nodes. upon stimulation, dc undergo maturation characterized by the expression of high levels of mhc ii and costimulatory molecules, leading to robust t cell activation. human blood dc are broadly defined as hla - dr positive leukocytes lacking expression of specific markers for t cell, b cell, nk cell, monocyte, and granulocyte lineages. they can be subdivided into the cd11c plasmacytoid dc population, which also express cd123, cd303 (bdca2), and cd304 (bdca4) ; and cd11c cd1c (bdca1) myeloid dc subset. it is well known that dc are critical regulators of the immune response and clues in the maintenance of peripheral and central tolerance. tolerogenic properties of dc depend on their maturation state, exposure to anti - inflammatory and immunosuppressive agents, the nature of the microbial stimuli, and environmental cues from the tissue microenvironment, as well as receptors expressed on their cell surface [4, 5 ]. in this regard, several reports demonstrate that the expressions of the inhibitory molecules ido, pdl, and icosl and receptors of the ilt family (ig - like transcripts) play a central role in conferring a tolerogenic state on dc [68 ]. ig - like transcripts (ilts), also called lymphocyte inhibitory receptors or leukocyte immunoglobulin- (ig-) like receptors (lir / lilrs) that correspond to cd85, are a group of membrane receptors coded by more than 10 genes located in the 19q13.4 chromosome. inhibitory lilrs transmit signals through their long cytoplasmic tails, which contain between two and four immunoreceptor tyrosine - based inhibitory domains (itims) that, upon phosphorylation, recruit shp-1 and shp-2 phosphatases, which are involved in the inhibition of different intracellular signal pathways. the best - characterized inhibitory receptors are ilt2 (lilrb1), ilt3 (lilrb4), and ilt4 (lirb2). ilt4 ligands are class i hla molecules. like the other inhibitory members of the ilt family, ilt4 recruits shp-1 protein tyrosine phosphatases and mediates a negative signal that inhibits early signaling events. ilt4 modulates several antigen - presenting functions mediated by myelomonocytic cells, such as cytokine production and costimulatory function, and it can also inhibit the activating signal triggered by fc receptors. it is also known that the continuous ligation of ilt2 and ilt4 inhibits dc differentiation and maturation [12, 13 ]. emerging data demonstrate that immunosuppressive factors, like il-10 and vitamin d, as well as t suppressor lymphocytes, induce the upregulation of ilt4 [12, 14 ]. dc expressing high levels of ilt3 and ilt4 cocultured with tetramers of soluble hla - g showed an impaired upregulation of the costimulatory proteins cd80 and cd86. thus, hla - g - ilt interaction leads to the development of tolerogenic dc with the consequent induction of anergic and immunosuppressive t cells. furthermore, dc expressing higher levels of ilt4 are able to induce regulatory t cells. inhibitory receptors, such as ilt2 and ilt4, are involved in the tolerogenic effect of dc and previous studies have indicated the important role of these receptors in the pathogenesis of autoimmune diseases [1820 ]. previous studies have shown that ilt2 may have a role in the pathogenesis of sle [2123 ]. we have demonstrated that peripheral blood mononuclear cells (pbmcs) isolated from patients with sle exhibit an impaired ilt2 function, whereas b cells express low levels of this receptor. regarding dc, it has been proposed that pdc play a pivotal role in the development of sle. the impaired clearance of apoptotic cells observed in sle and the opsonization of cellular apoptotic debris by autoantibodies enhances its uptake by pdc. moreover, these apoptotic particles are able to induce the synthesis of ifn-, which in turn favors the maturation of mdc and triggers isotype switching and autoantibody production by autoreactive b cells [2426 ]. however, the role of ilt4 in the pathophysiology of this autoimmune disease has not been elucidated. the aim of this work was to study the expression of ilt4 in peripheral blood dc and to study the inhibitory function of this receptor in monocyte - derived dendritic cells from sle and healthy patients. thirty - four patients (32 female and 2 male) with diagnosis of sle were included. diagnosis was made according to the classification criteria of the american college of rheumatology. mean age was 35.2 years, and mean duration of disease was 4.47 years at the time of the study. disease activity was scored according to the sledai index and the arithmetic mean of sledai was 5.96. the drugs included prednisone, hydroxychloroquine, azathioprine, mycophenolate mofetil, and cyclosporine, alone or in combination. thirty - four healthy individuals with similar age and same sex compared to patients were included as controls. in all cases, an informed written consent was obtained, and the local ethics committee (ethics and research committee of the hospital central dr. this work was carried out in accordance with the code of ethics of the world medical association (declaration of helsinki) for experiments involving humans. peripheral blood mononuclear cells (pbmcs) pbmcs were incubated with anti - cd14 mab coated microbeads followed by positive selection using macs single - use separation columns from miltenyi biotec (bergisch gladbach, germany). the purity of monocytes was assessed by flow cytometry analysis on the basis of cd14 expression and was always higher than 90%. for the in vitro generation of dc (modc), purified monocytes at a final concentration of 1 10 cells / ml were incubated in rpmi-1640 culture medium (gibco, grand island, ny) supplemented with 15% heat inactivated fetal bovine serum (fbs), 2 mm glutamine, 100 u / ml penicillin and 100 mg / ml streptomycin, nonessential amino acids and sodium pyruvate, gm - csf (50 ng / ml), and il-4 (15 ng / ml) for 6 days. culture medium and cytokines were replaced every 2 days. in order to evaluate the inhibitory function of ilt4 and its possible synergy with ilt2, dc were cultured for two additional days with lps (100 ng / ml) to induce maturation at three different conditions : in the presence or absence of the agonist anti - ilt4 purified antibody (10 g / ml) or in the presence of the agonist anti - ilt4 at the same concentration, plus the agonist anti - ilt2 purified antibody (20 g / ml) (biolegend, san diego, ca). cells were harvested at days 6 and 9, washed, labeled, and analyzed for the expression of the indicated maturation markers. the following monoclonal antibodies (mabs) were used : anti - cd83 labeled with apc, anti - cd80-fitc, anti - cd40-pe, anti - cd86 coupled to percp - cy5, anti - lin - fitc, anti - hla - dr - apc - cy7, anti - cd11c - percp - cy5.5 (bd biosciences, san jose, ca), anti - bdca1 and anti - bdca4 (miltenyi biotech) tagged with apc, and anti - ilt4 labeled with pe (biolegend, san diego, ca). for functional studies, purified anti - human ilt4 and purified anti - human ilt2 mabs were employed (biolegend, san diego, ca). pbmcs were labeled with 5 l of a fitc anti - human lineage antibody cocktail (anti - lin), 7 l of apc - cy7 tagged anti - hla - dr, 5 l of percp - cy5.5 labeled anti - cd11c, 7 l of apc labeled anti - bdca1 or anti - bdca4, and 5 l of anti - ilt4 pe, for 20 min at 4c. then, cells were washed, fixed with 1% pfa, and analyzed in a facsaria ii cytometer (bd biosciences), using the facsdiva and flowjo software (bd biosciences). dc derived from monocytes and in vitro generated were harvested at days 6 and 9 and labeled with 3 l of fitc anti - cd80, percp - cy5 anti - cd86, and pe anti - cd40. in all assays, fcr receptors were previously blocked with 10% human ab serum. in order to set gates, we used the fmo (fluorescence minus one) strategy. in brief, fmo controls leave out one reagent at a time (the opposite of single stain controls). in fmo, a control is defined as changing one condition at a time (figure 1). cytokines levels were determined in culture supernatants using the cytokine bead array (cba) kit for inflammatory cytokines (bd biosciences). in brief, supernatants from modc cultures and modc - t cells cocultures were collected and cytokine levels were quantified according to manufacturer instructions and then analyzed in facs canto ii (bd biosciences). briefly, mature modc were incubated in three different conditions, medium only, anti - ilt4 (10 g / ml), or anti - ilt4 (10 g / ml) + anti - ilt2 (20 g / ml), and then cocultured with allogenic lymphocytes of one healthy donor, in flat - bottomed 96-well plates precoated with a mixture of the anti - cd3 t3b mab (kindly provided by dr. sanchez madrid, hospital de la princesa, spain) and an anti - cd28 mab (10 g / ml). allogenic lymphocytes were previously loaded with 5.0 m carboxyfluorescein diacetate - succinimidyl - ester (cfda - se, molecular probes, eugene, or), according to manufacturer 's instructions. after five days of culture under standard conditions (with 5% co2 at 37c and 100% humidity), cells were harvested and analyzed by flow cytometry. cell proliferation was assessed by measuring the corresponding decrease in cell fluorescence by flow cytometry and the percentage of cell proliferation was normalized with the following formula : % cell proliferation = 100 ((% cells in nonstimulated culture/% cells in stimulated culture) 100). flow cytometry data were evaluated by using the mann - whitney u test. when indicated, kruskal - wallis test was also performed. the analysis of correlations between variables was based on spearman 's rank test ; p 0.05 for all cases, data not shown). in the first place, we assessed the phenotype of dc differentiated from monocytes of sle and healthy subjects by addressing the expression of cd11c, hla - dr, and cd83. we observed that dc from sle patients express the same levels of these differentiation markers, and we could not find significant differences between the expression of cd83 on dc from sle or healthy controls (figure 2(a)). modc from sle patients have been reported to display abnormal responses to different activation stimuli (lps, tnf-, pge2, or anti - cd40) compared to dc differentiated from healthy monocytes. consistent with these reports, we observed an abnormal response of modc to lps, characterized by a low induction of the costimulatory molecule cd40, analyzed as percentage of cd40 positive cells (figure 2(b)(a)) as well as by mfi (data not shown). we also detected a diminished expression of cd80 (figure 2(b)(b)) in response to lps in sle modc compared with healthy controls. cd86 expression in response to the activating stimulus lps was abnormal too ; modc from sle subjects showed diminished levels of surface expression of this costimulatory molecule in comparison to control modc (figure 2(b)(c)). disease activity worsened the response to lps in sle modc ; modc isolated from patients with a higher sledai index (8) showed lower expression levels of costimulatory molecules (cd80 and cd40) (figure 2(c)). it has been described that ilt2 ligation inhibits dc maturation ; however, a previous study performed in our laboratory showed that ilt2 poorly regulates modc maturation. thus, in order to evaluate the possible participation of ilt4 receptor and its synergy with ilt2, we induced modc maturation in the presence or absence of the anti - ilt4 and/or anti - ilt2 agonist mab. unexpectedly we did not find an apparent influence of ilt4 in the maturation of modc in healthy controls (figure 3(a)). cd40, cd83, cd80, and cd86 expression on healthy modc, measured as either percentage of positive cells or mfi, was not affected by continuous ligation of ilt4 or ilt2/ilt4 (figure 3(b)). interestingly, in sle patients ilt2 in synergy with ilt4 seemed to have a slight but evident effect on modc maturation. the percentage of cd40 and cd80 positive modc, as well as surface expression level of cd86 and cd83, tends to diminish in the presence of the continuous ligation of ilt2/ilt4 (figure 3(c)). in order to evaluate the possible effect of ilt4 and/or ilt2 signaling in the regulation of cytokine production by differentiated modc in vitro dc were generated in vitro as described in section 2 and maturated for 48 h with lps in the presence or absence of anti - ilt4 and/or anti - ilt2 agonistic mabs. tnf-, il-6, il-4, and il-10 concentrations were determined in culture supernatants (tables 2 and 3). continuous ligation of ilt4 and/or ilt2 did not affect il-6 production by modc from controls. in contrast, ilt4 plus ilt2 ligation induced a slight decrease in il-6 production by modc from sle patients (figure 4(a)). interestingly, in these patients, il-10 levels tended to be higher in response to ilt2 and ilt4 engagement (figure 4(b)). finally, in order to assess the role of ilt4 and/or ilt2 in the regulation of immunogenic ability of modc, we performed cocultures of modc maturated in the presence or absence of ilt4 and/or ilt2 agonistic mabs with allogenic pbmc. as mentioned before, ilt4 ligation has been described to confer a lower immunogenic capability on dc. we found that, in sle patients, ilt4 ligation (alone or in combination with anti - ilt2 mab) conferred the ability to inhibit pbmc proliferation on modc, which was not observed in healthy controls (figure 5). dc are professional antigen - presenting cells and initiators of the immune response ; however, now it is clear that they have a fundamental role in the maintenance of immune tolerance. it had been postulated that immature dc promote tolerogenic responses, whereas mature dc promote immunogenic responses. recent studies have shown that, under certain circumstances, mature dc can exert a tolerogenic effect. in this regard, it has been reported that the expressions of regulatory receptors belonging to the ilt family, mainly ilt2, ilt3, and ilt4, are associated with a tolerogenic phenotype, inhibiting the expression of costimulatory molecules and triggering il-10 production [31, 32 ]. autoimmune diseases are a consequence of a loss of immune tolerance ; it has been described in different animal models that the absence of regulatory receptors that possess inhibitory motifs (itims), including ilt molecules, is associated with autoimmune diseases. our group has previously reported that t lymphocytes from sle patients show an abnormal expression and a defective function of the inhibitory receptor ilt2 ; even more, we showed that sle patients have a lower expression of ilt2 on peripheral mdc and pdc compared to healthy controls ; however, when we assessed ilt2 function on modc from sle patients, we observed that this receptor does not have a critical role in regulating dc maturation. the latter suggests that another receptor may be implicated in this response. in order to assess this possibility, we analyzed the expression and function of another inhibitory receptor of ilt family, ilt4. we found that sle patients showed lower levels of ilt4 positive circulating pdc and mdc. this diminished expression of ilt4 may contribute to a higher immunogenic phenotype of dc in sle. similar to ilt2 expression, we did not find an association of ilt4 expression with disease activity measured by sledai or any current medication, which may suggest an intrinsic alteration in dc rather than a result of the inflammatory milieu observed in sle patients. it has also been described that monocytes from psoriatic arthritis patients showed a diminished expression of ilt4, which indicates that an alteration of these inhibitory receptors may not be exclusive of sle patients but a common feature with other autoimmune diseases. we observed that modc from sle patients display aberrant responses to a maturation stimulus. in agreement with previous studies, the expression of cd80, cd86, and cd40 after culture with lps was diminished in modc from lupus patients compared with healthy controls [29, 33, 34 ]. ding. in 2006 demonstrated that the expressions of maturation and differentiation markers (cd80, cd86, and hla - dr) were significantly higher in modc from sle patients than in healthy controls in the absence of exogenous maturation stimuli (lps). they also report that, compared with healthy controls, the upregulation of maturation markers in response to maturation stimuli was blunted in the lupus group. reported increased levels of cd80 and cd86 expression in peripheral blood dc from patients with sle, and they demonstrated an impaired response to lps in modc from these patients. it is possible that the defective response to lps of lupus modc may be due to a preactivation state that makes them refractory to further activation signals. modc from sle patients with a sledai index 8 expressed significant lower levels of cd40 and cd80. it is clear from these results that the inflammatory microenvironment may contribute to this abnormal response observed in sle patients. it has been described that ilt receptor inhibits dc maturation ; however, our previous results showed that ilt2 does not have great impact on inhibiting the modc upregulation of costimulatory molecules following a maturation stimulus like lps. when we assessed ilt4 role in modc maturation, we observed that interestingly in healthy controls ilt4 does not inhibit modc maturation alone nor in combination with ilt2. nevertheless, in sle patients, ilt2 and ilt4 showed a slight effect on modc, inducing a discrete reduction in the expression of costimulatory molecules. we hypothesize that this apparently contradictory result is due to the effect of other inhibitory receptors ; thus, in healthy individuals the inhibitory receptors ilt2 and ilt4 could play a secondary role in the generation of tolerance of dc, while other molecules, like pdl-1, ox-40l, and icosl, may play a crucial role in inducing that regulatory phenotype ; conversely, in sle patients, the existence of a function impairment of the receptors mentioned above may highlight the inhibitory effect of ilt2 and ilt4 not observed in healthy controls. in this regard, carvalheiro. have found a lower expression of icosl mrna in monocytes and pdc from sle patients with active disease. another report shows that monocytes and mdc from sle patients have lower levels of the inhibitory receptor pdl-1. it is worth mentioning that in this study we have not assessed the contribution of other ilt family members, such as ilt1, which with their interaction with mhc class i molecules, expressed in dc, may counteract ilt2 and ilt4 function. in previous reports, the authors showed that the simultaneous ligation of ilt4 and ilt2 induces an arrest of maturation of dc ; however, these results may be due to the protocol used for the differentiation of monocytes into dc since they added tgf- to the differentiation culture ; it is known that tgf- increases the levels of ilt receptors and thus an increased level of ilt expression may allow the appreciation of a greater effect after the ligation of these receptors. in regard to modc function, it has been demonstrated that modc from sle patients induce higher activation and proliferation of allogenic pbmcs than modc from healthy controls. jin. found that circulating pdc from sle had an increased ability to stimulate t cells when compared with control pdc. the continuous ligation of ilt2 and ilt4 has been associated with a lower immunogenic capability of modc [12, 38 ]. silencing of inhibitory ilt expression in apc has been found to increase t cell proliferation and synthesis of proinflammatory cytokines. we observed that either ilt2 or ilt4 signaling does not modify the immunogenic ability of dc from healthy controls ; we could only appreciate a slight effect in the inhibition of alloproliferation of lymphocytes from this group. liang. showed that the inhibitory signal through ilt receptors depends on the specific ligand present in the culture. in this study, liang. they observed that hla - g5 dimer and hla - g1 tetrameric complexes have a high capacity to induce an inhibitory signal and modulation of dc activation and maturation, while hla - g5 monomer did not trigger an inhibitory signal in dc, concluding that the role of different isoforms of hla - g depends on their concentration and conformation, the latter affecting binding to a specific receptor. on this basis, under our experimental conditions, ilt4 signaling does not seem to impact dc function but the real impact of this receptor in vivo may be difficult to elucidate since the different ligands present in the microenvironment may change easily. however, dc from sle patients showed a decrement on its immunogenic capability upon ligation with ilt2 and ilt4, which supports the hypothesis that in healthy subjects the control of dc activity may rely on other inhibitory receptors ; in contrast, in sle patients the function of these inhibitory receptors may be impaired, and then ilt4 function is more evident. dc from sle patients showed an impaired production of cytokines, mainly il-10 and il-6. there is also evidence that levels of il-10 decreased after corticosteroid and chloroquine treatment. in this respect, it is important to point out that several of the studied patients were under therapy with chloroquine (table 1), and we can not exclude the treatment effect on the cytokine levels detected. in conclusion, we found that in nonpathological conditions ilt4, alone or in synergy with ilt2, does not have a crucial role in regulating maturation and immunogenic function of dc, and these characteristics may possibly rely on other inhibitory receptors, such as pdl-1, ox-40l, or icosl. it is feasible that, in sle patients, defects on these receptors highlight ilt2 and ilt4 function ; however, even when the function of ilt4 is preserved in dc from sle patients, the diminished percentages of ilt4 circulating dc may have a role in sle pathogenesis. | dendritic cells (dc) play an important role in the development and maintenance of immune tolerance. although the inhibitory receptor ilt4/lilrb2 has been related with the tolerogenic phenotype of dc, the possible role of this receptor in the breakdown of dc tolerogenic function in systemic lupus erythematosus (sle) has not been elucidated. in this study, we analyzed the expression and function of the inhibitory receptor ilt4 in dc from sle patients. we found that the percentage of ilt4 positive plasmacytoid dc and myeloid dc is significantly diminished in sle patients. interestingly, ligation of ilt4 did not affect the maturation or immunogenic capability of dc in healthy controls. in contrast, in sle patients we observed an inhibitory effect of ilt4 on the immunogenic capability of dc. ilt4 was shown not to have a crucial role in regulating the maturation and function of dc from healthy controls but is partially involved in the maturation process and immunogenic capability of dc from sle patients, suggesting that other inhibitory receptors, involved in the regulation of dc tolerogenic function, may be impaired in this autoimmune disease. |
the oral anticoagulant therapy (oat), used to prevent thrombosis, is associated with substantial avoidable hospitalization. identify the associations between chronic care management and the quality of oat as suggested by the chronic care model (ccm) of wagner. regression analysis with data of 61 thrombosis clinics and inductive analysis with 63 interviews with health care professionals of 23 thrombosis clinics. results show substantial differences between regions in the quality of thrombosis care and the ccm activities. however, the variation in quality of care was not associated with the differences in ccm activities. several preferred ccm activities (e.g., multidisciplinary protocol) as well as the barriers to implement these activities (e.g., conflicting interests) were put forward by the health care professionals. it can be concluded that there is variation in quality of thrombosis care between regions. | introductionthe oral anticoagulant therapy (oat), used to prevent thrombosis, is associated with substantial avoidable hospitalization.aimidentify the associations between chronic care management and the quality of oat as suggested by the chronic care model (ccm) of wagner.methodsregression analysis with data of 61 thrombosis clinics and inductive analysis with 63 interviews with health care professionals of 23 thrombosis clinics.resultsresults show substantial differences between regions in the quality of thrombosis care and the ccm activities. however, the variation in quality of care was not associated with the differences in ccm activities. the inductive analysis indicates that there are problems in the cooperation between caregivers. several preferred ccm activities (e.g., multidisciplinary protocol) as well as the barriers to implement these activities (e.g., conflicting interests) were put forward by the health care professionals.conclusionit can be concluded that there is variation in quality of thrombosis care between regions. this variation could not be explained by the observed differences in ccm activities. however, fragmentation is a major source of inefficiency according to health care professionals. the paper concludes with suggestions to improve chronic care management for thrombosis. |
a recent genome - wide association study (gwas) found a sequence variant in dab2ip (rs7025486[a ]) to be strongly associated with the presence of abdominal aortic aneurysm (aaa) with a per - allele odds ratio (or) of 1.21 (p= 4.6 10). the authors also found an association with early - onset myocardial infarction (mi) (or 1.18, p= 3.1 10), mi at all ages (or= 1.08, p= 0.0012), peripheral arterial disease (pad) (or= 1.14, p= 3.9 10), venous thrombo - embolism (vte, or 1.12, p= 0.0079), and pulmonary embolism (or= 1.20, p= 0.00030) but not intracranial aneurysm or ischaemic stroke. this variant did not appear to act through classical intermediate phenotypes such as smoking, lipids, obesity, type 2 diabetes (t2 dm), and hypertension. dab2ip, located on chromosome 9q33, is a gtpase - activating protein thought to play an important role in prostate cancer metastasis. a single - nucleotide polymorphism (snp) in this gene has been associated with aggressive prostate cancer, whereas in vitro functional studies have demonstrated that loss of the protein leads to enhanced cell proliferation and reduced apoptosis, via the pi3-akt pathway. it is possible therefore, that this snp exerts its effect by regulating cell senescence and proliferation. in 2007, three groups reported that another locus on the short arm of chromosome 9 at p21.3, tagged by the snp rs10757278, was strongly associated with coronary heart disease (chd). this snp was also subsequently found to be associated with the risk of aaa and pad but does not appear to act through classical intermediate phenotypes. there is mounting evidence to suggest that this snp affects expression of the large non - coding rna anril, which in turn may affect expression of nearby genes such as the cdkn2a / b cluster which also play a role in cellular proliferation and senescence. in addition, associations with circulating biomarkers of cardiovascular disease (cvd), including lipids, inflammatory markers, and haemostatic markers, were investigated. since shorter leucocyte telomere length (ltl) has been consistently shown to be associated with increased risk of chd in both population - based case control studies and patients with familial hypercholesterolaemia (fh), a monogenic form of premature chd, we examined the relationship between this snp and telomere length. finally, whether or not this variant, in combination with the 9p21 locus and the framingham risk score (frs), could improve the prediction of chd over and above the frs alone in the northwick park heart study ii (nphs - ii) prospective study of uk men was investigated. nphs - ii is a prospective study of healthy middle - aged men (5064 years) recruited from nine uk general practices. in the 2742 caucasian men with genotype data, by december 2009, there had been 272 chd events comprising 175 acute chd events (42 fatal), 74 coronary artery revascularization procedures, and 23 silent mi. the hifmech study compares male survivors of a first mi aged 7.5 mmol / l) with 127 definite chd events as defined in neil. the udacs consists of 1014 consecutive subjects recruited from the diabetes clinic at university college london hospitals nhs trust (uclh) 200102 (629 men ; 600 caucasians with t2 dm). all patients had diabetes according to the who criteria and analysis was restricted to the caucasian subjects with t2 dm to remove possible heterogeneity within the sample. the coronary artery bypass graft (cabg) patients were drawn from the coronary artery surgery inflammation study and are described elsewhere. briefly, all patients undergoing elective first - time cabg at the middlesex hospital, london, uk, between october 1999 and september 2000 were invited to participate. subjects undergoing additional surgical procedures (such as valvular surgery or aneurysmectomy), subjects with evidence of a pre - existing inflammatory state or unstable coronary artery disease, and subjects who suffered potentially confounding infective post - operative complications or circulatory failure requiring inotropic support were excluded. the cabg group includes 439 people (20% women) having different ethnic origin (83% caucasians, 8% asians, 2% afro - caribbean, 2% of other ethnicity, and 5% of unknown origin). table 1baseline characteristics of studies udacsnphs - iisimon broomehifmechcabgchd, n= 358chd+, n = 135p - valuechd, n= 2406chd+, n= 274p - valuechd, n= 214chd+, n= 127p - valuechd, n= 554chd+, n= 518p - valuechd, n= 332age (years)66.2 (10.9)69.5 (9.9)0.00356.0 (3.4)56.6 (3.5)0.0144.6 (13.8)56.5 (10.4) 7.5 mmol / l) with 127 definite chd events as defined in neil. the udacs consists of 1014 consecutive subjects recruited from the diabetes clinic at university college london hospitals nhs trust (uclh) 200102 (629 men ; 600 caucasians with t2 dm). all patients had diabetes according to the who criteria and analysis was restricted to the caucasian subjects with t2 dm to remove possible heterogeneity within the sample. the coronary artery bypass graft (cabg) patients were drawn from the coronary artery surgery inflammation study and are described elsewhere. briefly, all patients undergoing elective first - time cabg at the middlesex hospital, london, uk, between october 1999 and september 2000 were invited to participate. subjects undergoing additional surgical procedures (such as valvular surgery or aneurysmectomy), subjects with evidence of a pre - existing inflammatory state or unstable coronary artery disease, and subjects who suffered potentially confounding infective post - operative complications or circulatory failure requiring inotropic support were excluded. the cabg group includes 439 people (20% women) having different ethnic origin (83% caucasians, 8% asians, 2% afro - caribbean, 2% of other ethnicity, and 5% of unknown origin). table 1baseline characteristics of studies udacsnphs - iisimon broomehifmechcabgchd, n= 358chd+, n = 135p - valuechd, n= 2406chd+, n= 274p - valuechd, n= 214chd+, n= 127p - valuechd, n= 554chd+, n= 518p - valuechd, n= 332age (years)66.2 (10.9)69.5 (9.9)0.00356.0 (3.4)56.6 (3.5)0.0144.6 (13.8)56.5 (10.4) 20%. in the nphs - ii at recruitment, adopting this policy would result in just 35 (1.6%) of men being offered treatment, in part because men with prevalent chd or being treated with preventative medications were excluded. we found that addition of the two - snp gene score to the frs improved risk stratification as measured by the nri of 11.1% (p= 0.007, 95% ci 2.919.4). if a policy was adapted whereby people with an frs > 20% or an frs + gs > 20% in the nphs - ii cohort were offered treatment, then the number of men who would qualify increases three - fold in the group who went on to develop chd. it has been observed that the frs tends to over - predict cvd in high - risk groups but under - predict cvd in low - risk groups. compared with the general population, the participants in nphs - ii are a healthy cohort which is one reason why the frs performs poorly as measured by the aroc. we have shown that in this group of patients, the addition of genotypes to the prediction model improved performance as measured by the aroc and the more clinically relevant nri. further research is required to assess whether or not these results are applicable on a population level. this study has confirmed the effects of a common variant in dab2ip (rs7025486) on the development of chd. prediction models which include crfs and genotypes, which act through pathways independent of the crfs, are likely to improve their performance. even the small increment in aroc seen in this study has potential clinical utility when thresholds used for treatment in the uk are considered. understanding the mechanism by which this variant exerts its effect should be the focus of ongoing research. s.c.h. is supported by the bhf as a chair scholar, and s.e.h., reecha sofat is supported by a british heart foundation (schillingford) clinical training fellowship (fs/07/011). the nphs - ii study was supported by the medical research council, the us national institutes of health (nih 33014), and du pont pharma. the hifmech study was supported by the european commission (bmh4-ct960272), the swedish medical research council, the swedish heart lung foundation, inserm, universit de la mditerrane (inserm u626), foundation pour la recherche mdicale (frm), and programme hospitalier de recherche clinique (phrc 1996). hifmech co - investigators are a.h., s.e.h., irne juhan - vague, maurizio margaglione, giovanni di minno, john yudkin, and elena tremoli. we would like to thank the members of the simon broome bhf study for access to patients samples : dr rossi naoumova, prof. the wellcome trust case control consortium was funded by the wellcome trust (076113/b/04/z). funding to pay the open access publication charges for this article was provided by the british heart foundation. | aimsa sequence variant, rs7025486[a ], in dab2ip on chromosome 9q33 has recently been associated with coronary heart disease (chd). we sought to replicate this finding and to investigate associations with a panel of inflammatory and haemostatic biomarkers. we also sought to examine whether this variant, in combination with a chromosome 9p21 chd variant (rs10757278) and the framingham risk score (frs), could improve the prediction of events compared with the frs alone.methods and resultsrs7025486 was genotyped in 1386 chd cases and 3532 controls and was associated with chd [odds ratio (or) of 1.16, 95% confidence interval (ci) 1.051.29, p= 0.003 ]. meta - analysis, using data from the original report and from genome - wide association studies in both the wellcome trust case control consortium and the cardiovascular health study, comprising 9968 cases and 20 048 controls, confirmed the association (or of 1.10, 95% ci 1.061.14, p= 3.2 106). there was no association with a panel of chd biomarkers, including any lipid, inflammation, or coagulation trait, nor with telomere length. addition to the frs of this variant plus rs10757278 on chromosome 9p21 improved the area under the receiver - operating characteristic curve (aroc) from 0.61 to 0.64 (p= 0.03) as well as improving the reclassification (net reclassification index = 11.1%, p= 0.007).conclusionthis study replicates a previous association of a variant in dab2ip with chd. addition of multiple variants improves the performance of predictive models based upon classical cardiovascular risk factors. |
ferromagnetic nanostructures are an important part in basic research but also in nanotechnological applications like magneto - optical devices, high density data storage, and also in biomedicine such structures at the nanoscale are promising candidates for example in drug delivery, imaging or targeting of special cells. large area fabrication of periodically arranged nanostructures by self - organization has been carried out in using anodized porous alumina as template for depositing ferromagnetic nanowire arrays. the use of porous templates for embedding ferromagnetic materials increases the coercivity and squareness of hysteresis loops compared to thin metal films. magnetic materials in the nanometre scale exhibit changed properties compared to bulk material and therefore offer great potential for nanotechnological applications. the nanoscopic systems consist of either particles or wires with magnetic properties due to their geometry and arrangement. in general, for applicability of the system, the magnetic nanostructures need to be ferromagnetic at room temperature. in some cases, a high anisotropy between the two magnetization directions, perpendicular and parallel to the surface, is of interest, and thus needle - like structures are favourable due to their high demagnetizing field. furthermore, the interaction among the nanowires, which is mainly caused by dipolar coupling, is investigated. one method to achieve low - dimensional structures is the deposition of metal nanostructures on patterned surfaces or into porous membranes with channels perpendicular to the surface, and therefore the arrangement of the metal structures exhibit a high spatial density with respect to the sample surface. templates like porous alumina or polycarbonate foils are usually electrochemically fabricated and afterwards filled with a magnetic material by electrochemical deposition. in commercial microelectronics, most devices are based on silicon technology and thus for compatibility a silicon substrate is a precondition for applicability. therefore, the employment of silicon as base material is of interest. semiconducting / ferromagnetic composite systems that operate at room temperature are required. the presented nanocomposite, consisting of a porosified silicon matrix and embedded ferromagnetic nanostructures can be tuned in their magnetic behaviour by controlling the electrochemical deposition parameters. as template for the incorporation of ferromagnetic nanostructures, porous silicon (ps) offering morphologies in the meso / macro porous regime is used. for the preparation of single - sided as well as for double - sided porous silicon, a double - tank electrolytic cell is utilized with hf - solution on both sides. the electrolyte also acts to contact the anodic side of the sample. in the first case, a constant current density between 50 and 100 ma / cm is employed, whereas the double - sided specimens are fabricated with an alternating current. the frequency is typically 0.1 hz. under these conditions, pore - diameters of 40 nm up to 80 nm can be achieved dependent on the applied current density. for the presented investigations, ps - matrices with an average pore - diameter of 80 nm and an interpore - spacing of about 40 nm are used. the incorporation of the nanostructures is performed by electrochemical deposition of a metal from a metal salt solution. the metal deposition is carried out by pulsed deposition technique with frequencies between 0.025 and 0.1 hz. the applied current density has been varied between 10 and 25 ma / cm. the electrolyte is composed of nicl and niso4 for ni - deposition and of coso4 for co - deposition. to obtain a nico alloy, the ni- and co - salt solutions are mixed in the ratio 2:1. to achieve an extension of the nanosystem leading to novel magnetic behaviour, silicon wafers have been etched on both sides resulting in two porous layers of about 30 m each. these double sided matrices, offering the same morphology on both sides are filled with either the same metal on both sides or with two different metals. to reduce the thickness of the remaining silicon bulk material in between the porous layers, the wafer has first been thinned down to about 45 m and then been anodized on both sides (fig. 1). both layers offer a thickness of about 10 m each, thus the remaining bulk silicon is 25 m. the aim is to achieve samples with very thin layers of remaining bulk silicon (around ten nanometres) to investigate the magnetic interaction between the two layers. thinned silicon wafer with an entire thickness of about 45 m porosified on both sides. the two porous silicon layers have a thickness of about 10 m each the morphology and structure of the nanocomposite material is characterized by scanning electron microscopy. magnetization measurements are performed by squid - magnetometry, whereas the sample with an area of 12 mm is placed as usual within a straw, which is mounted on the sample holder. the magnetic field is applied either perpendicular or parallel to the sample surface that means in case of the investigated samples in easy axis or hard axis direction (parallel or perpendicular to the pores). considering magnetization measurements of a porous silicon / metal nanocomposite, one sees that the magnetic behaviour is composed of two terms. a first one is observed at magnetic fields below the saturation magnetization of the incorporated metal. this behaviour is due to the ferromagnetic behaviour of the metal structures and strongly depends on the geometry of the precipitations. samples containing mainly metal particles offer a higher coercivity but the magnetic anisotropy is less than for specimens containing more needle - like structures. comparing ni and co - filled samples, one can see that in both cases, the dependence on the geometry is similar. in case of particles deposited within the pores, having a similar spatial distribution for both materials, the anisotropy between the two magnetization directions is about 50%, whereas in case of co particles of similar size and density of the spatial distribution, the anisotropy is in the range of only 10%. this indicates that the ni particles strongly interact along the pores in contrast to the co particles, which seem more or less uncoupled. figure 2 shows a scanning electron micrograph, gained from back scattered electrons, of a double - sided porous silicon sample. one side is filled with ni, the other one with co. the hysteresis loop of this sample exhibits two different slopes caused by the different saturation magnetization of the two deposited metals. first, up to a field of 500 oe, the ferromagnetic behaviour of ni is dominant, and above the saturation of the ni - structures, the behaviour of the co structures, which are saturated at higher fields, becomes more distinctive (fig. sem - image gained from the back scattered electrons shows the cross section of the two porous layers of a double - sided sample. one side is filled with ni, the other one with co. the remaining bulk silicon layer between the two layers is about 450 m, which is not shown in the picture magnetization measurements performed on a double sided etched porous silicon sample, whereas the two porous layers are filled with two different metals, namely ni and co. due to the distinct saturation magnetization of the two deposited metals, the hysteresis loop shows two different slopes a further magnetic term is observed at magnetic fields greater than the saturation magnetization of the incorporated metal. in this high field region up to an available field of 7 t, the samples show an enhancement of the magnetization with increasing magnetic field without saturation. this non - saturating magnetization term is observed independent of the shape of the embedded metal - structures. above the saturation magnetization of the incorporated metal, the temperature dependence of the high field term shows a paramagnetic - like behaviour and follows exactly the curie the non - saturating increase in the magnetization with the applied magnetic field is independent on the geometry of the deposited metal structures but strongly depends on the kind of deposited metal and is much less for co than for ni. considering samples with a porous silicon layer on each side and both of them filled with a different metal (ni, co), one can also observe this non - saturating term at high magnetic fields, which is a mixture of the contributions of both materials. in fig. for all investigated samples, ni-, co- and ni / co - filled, this unexpected non - saturating high - field term exhibits an enhancement with increasing magnetic field, which is nearly linear, measured at temperatures above 80 k. the occurrence of this additional high - field contribution is still not completely understood but there are hints to be caused by orbital currents in the silicon skeleton. non - saturating term occurring at high magnetic fields above the saturation magnetization of the deposited metal measured on a double - sided sample with two different metals deposited (ni, co). the measurements are performed between 4.2 and 310 k with an applied magnetic field perpendicular to the sample surface. a temperature dependence is observed showing a decrease in the magnetization with increasing temperature a new kind of magnetism is also observed by some groups in usually diamagnetic systems as thiol capped gold - nanoparticles or thin gold layers caused by a strong spin an enhancement of the orbital moment and the magnetic anisotropy by a tetragonal distortion of the lattice of feco - alloy films is demonstrated by. recently, a unique kind of giant magnetic behaviour observed in organic monolayers is explained by bose condensation of the electrons into a single low angular momentum quantum state caused by triplet pairing. considering the ps / metal composite, the occurrence of the non - saturating paramagnetic term could be explained by an interface magnetism caused by triplet - pairing of carriers injected into the si - skeleton. the presented nanocomposite is fabricated during a low - cost two - step electrochemical process. porous silicon, tunable in its morphology, acts as template for the incorporation of ferromagnetic nanostructures. the silicon wafers are either anodized on a singe side or on both sides and subsequently filled with ni, co or both materials, one on each side. a sophisticated extension of this preparation technique is the etching and filling of double - sided porous silicon specimens in using ultrathin silicon wafers with an entire thickness of about 45 m. the scope of preparing such samples is the investigation of the mutual magnetic influence of the two metal - filled porous layers. for this purpose, the remaining bulk silicon in between the two porous layers has to be in the range of 10 nm that could not have reached so far. furthermore, the investigated semiconductor / metal nanocomposites exhibit two characteristic magnetic terms, a first one at magnetic fields below the saturation magnetization of the incorporated metal, which is due to the ferromagnetism of the metal structures and a second one at higher fields, above the saturation magnetization. this additional occurring magnetic high field term is paramagnetic - like and shows a temperature dependence following the curie this unexpected property is observed for single - sided samples as well as for double - sided specimens filled with one metal or with two different metals. in case of double - sided samples, the magnetic behaviour is a mixture of both, caused by the deposited ni - structures and the co precipitates. because the metal deposition can be strongly influenced by the process parameters, samples with desired ferromagnetic properties as magnetic anisotropy, remanence and coercivity can be fabricated. in this low field region, the magnetic behaviour is strongly correlated with the structural and morphological features of the specimens and depends on the size, shape and spatial distribution of the deposited metal structures. in contrast, the unexpected term at high magnetic fields is independent of the geometry of the metal precipitations. the enhancement of the magnetization with the applied field is less in case of co compared to ni and is more or less linear above 80 k. the authors would like to thank sanja simic from the institute of electron microscopy at the university of technology graz for her efforts in making scanning electron micrographs, dr. armando loni from intrinsiq materials, malvern, uk for thinning the wafers and also prof. | a magnetic semiconductor / metal nanocomposite with a nanostructured silicon wafer as base material and incorporated metallic nanostructures (ni, co, nico) is fabricated in two electrochemical steps. first, the silicon template is anodized in an hf - electrolyte to obtain a porous structure with oriented pores grown perpendicular to the surface. this etching procedure is carried out either in forming a sample with a single porous layer on one side or in producing a double - sided specimen with a porous layer on each side. second, this matrix is used for deposition of transition metals as ni, co or an alloy of these. the achieved hybrid material with incorporated ni- and co - nanostructures within one sample is investigated magnetically. the obtained results are compared with the ones gained from samples containing a single metal. |
gastroesophageal reflux disease (gerd) broadly includes the whole spectrum of reflux disease, from intermittent symptoms like heartburn or acid regurgitation to endoscopic reflux esophagitis and barrett 's esophagus.1 it usually gives a considerable impact on the quality of the patient 's life not only by the symptoms, but also by the following consultation procedures and medical cares. while gerd is a common disease and also the major upper gastrointestinal problem in western countries, its prevalence amongst asian has been reported to be relatively low.2 - 4 during the recent decade, several studies about prevalence of symptom - based gerd and endoscopic reflux esophagitis have revealed generally higher number of patients compared to other previous asian studies. time trend studies have also shown the increase of prevalence both in symptom based - gerd and endoscopic reflux esophagitis.5 heartburn and acid regurgitation are the characteristic symptoms of gerd. heartburn is defined as a burning sensation at the retrosternal area. however, different criteria of gerd have been published from all over the world including asia, with the frequency of its symptoms differing from once a week to even once a year. furthermore, it also has been attributed to the lack of the exact word for heartburn in some asian languages, such as chinese or korean.6 in addition, there has not been any consensus distinguishing gerd from dyspepsia. in asia, endoscopic reflux esophagitis is quite commonly diagnosed because the cost of endoscopic examination is relatively inexpensive. actually, a lot of asymptomatic people get the upper endoscopic examinations for gastric cancer screening and comprehensive medical check - up. the major limitation of studies with individuals in screening program is that it might not represent the general population. however, such studies have advantages of their large sample size and consistent diagnostic manners. this paper was aimed to review the epidemiologic aspect of gerd and its related disease manifestations, such as endoscopic reflux esophagitis, barrett 's esophagus and extra - esophageal syndrome, according to various definitions, study settings, publication years and geographical regions in asia. a systematic pubmed search was performed to identify all of the reports written about the prevalence of gerd, published from january 1995 to october 2010, using combinations of the following index terms : " gastroesophageal reflux disease, " " reflux, " " gastroesophageal reflux " or " esophagitis " and " prevalence " or " epidemiology. " included studies had to of these 3 following criteria : (1) including epidemiologic studies performed with at least 200 subjects gathered by population - based or medical check - up settings ; (2) having detailed description of gerd definition or its related manifestations and (3) subjecting any sample type, including subjects from tertiary hospitals, to collect data about extra - esophageal symptoms or barrett 's esophagus. following information was abstracted from each study included : the year of publication, study periods, country of subjects, sample types (the population - based type, subjects who underwent the medical check - up or those from referral hospitals), study design (derived from case - control, cohort or other cross - sectional studies), sample size and prevalence of gerd, reflux esophagitis, barrett 's esophagus or extra - esophageal syndromes of gerd. all studies were sub - grouped by each geographical region, based on globocan 2008, the project of the international agency for research on cancer which provides contemporary estimates of the incidence, prevalence and mortality from major types of cancers for all countries over the world.7 the asian geographic area includes these 4 regions of eastern (china, japan, korea and taiwan), southeastern (malaysia, singapore and thailand), south central (india, iran and pakistan) and western (israel and turkey) asia. among a total of 3,440 papers searched by those key words, 1,696 papers were excluded from this study because they were not written by english or their subjects were not adults or human. a systematic pubmed search was performed to identify all of the reports written about the prevalence of gerd, published from january 1995 to october 2010, using combinations of the following index terms : " gastroesophageal reflux disease, " " reflux, " " gastroesophageal reflux " or " esophagitis " and " prevalence " or " epidemiology. " included studies had to of these 3 following criteria : (1) including epidemiologic studies performed with at least 200 subjects gathered by population - based or medical check - up settings ; (2) having detailed description of gerd definition or its related manifestations and (3) subjecting any sample type, including subjects from tertiary hospitals, to collect data about extra - esophageal symptoms or barrett 's esophagus. following information was abstracted from each study included : the year of publication, study periods, country of subjects, sample types (the population - based type, subjects who underwent the medical check - up or those from referral hospitals), study design (derived from case - control, cohort or other cross - sectional studies), sample size and prevalence of gerd, reflux esophagitis, barrett 's esophagus or extra - esophageal syndromes of gerd. all studies were sub - grouped by each geographical region, based on globocan 2008, the project of the international agency for research on cancer which provides contemporary estimates of the incidence, prevalence and mortality from major types of cancers for all countries over the world.7 the asian geographic area includes these 4 regions of eastern (china, japan, korea and taiwan), southeastern (malaysia, singapore and thailand), south central (india, iran and pakistan) and western (israel and turkey) asia. among a total of 3,440 papers searched by those key words, 1,696 papers were excluded from this study because they were not written by english or their subjects were not adults or human. details of published studies satisfying the inclusion criteria on the symptom - based gerd (ie, symptoms of heartburn or acid regurgitation occurring at least once a week), in the population - based studies are listed in table 1. they generally used methods of face - to - face or telephone interviews or the postal questionnaires. the largest sample group was consisted of eastern asia studies, followed by those from south central asia (figure). the prevalence of symptom - based gerd in eastern asia was 5.2%-8.5%8 - 13 from 2005 to 2010, while it was 2.5%-4.8%14 - 16 before 2005. the prevalence of gerd in iran was 6.3%-18.3%17 - 20 from 2005 to 2010, which seemed more prevalent than in eastern asia. before 2005, 2 population - based studies from this country with different definitions of gerd also showed similar results.21,22 on the other hand, the time trend of gerd prevalence showed drastic change between 2 cross - sectional surveys of the general population in singapore in southeastern asia. the first survey which was held in 1994 showed the prevalence of gerd by at least monthly symptoms to be around 5.5% 1.5%, while it has increased to 10.5% 2.0% after 5 years (or, 2.2 ; 95% ci, 1.0 - 5.2 ; p = 0.05).23 however, the sample size of this study was relatively small and this increased result might also have been attributed to the increased awareness. the prevalence in western asia was found to be the highest among the whole asian region as represented by 20% in turkey. one population - based study performed in israel (2007) also reported the high prevalence of gerd symptoms, including 6.5% of retrosternal burning, 5.2% of retrosternal pain, 10.4% of acid taste in the mouth and 7.9% of the reflux of gastric contents.24 the list of studies published regarding the prevalence of endoscopic reflux esophagitis is summarized in tables 2 and 3. most endoscopy - based studies were conducted with medical check - up participants or patients having upper gastrointestinal symptoms who visited the referral hospitals. most of the gerd endoscopic studies were consisted of eastern asian studies including japan, china and korea. the prevalence of endoscopic reflux esophagitis in eastern asia was 3.4%-5.0%25,26 before 2000, with these 2 studies using the definition of reflux esophagitis by savary - miller classification, while other 9 studies showed results of 6.6%-15.0%27 - 31 from 2000 to 2005 and 4.3%-15.7%32 - 35 after 2005, with the definition by la classification. however, it is quite uncertain why such a wide range of prevalence has been found for endoscopic reflux esophagitis. furthermore, several studies were conducted in retrospective manner and might have under- or over - estimated the exact prevalence of endoscopic reflux esophagitis. the intensity and frequency of reflux induced symptoms are poor predictors for finding the presence or the severity of endoscopic mucosal breaks (erosion or ulcer). in the medical check - up studies, the prevalence of gerd based on symptoms like heartburn or acid regurgitations at least once a week was 5.0%-8.2%,31,34,36 which were similar with those of population - based studies. asymptomatic reflux esophagitis was reported in 33.6%-84.0% among the subjects with reflux esophagitis.32,34 this finding might be a true reflection of community or caused by the possible over - diagnosis of endoscopic reflux esophagitis by including mild reflux esophagitis or minimal changes. non - erosive reflux disease (nerd) has been commonly defined as the presence of classic gerd symptoms in the absence of esophageal mucosal injury which has been detected during the upper endoscopy.37 nerd is considered as the major subcategory of gerd, which has been assumed with an increasingly important role. the prevalence of nerd in medical check - up studies was reported from 3.1% to 4.0%, comprising about 70%-80% of gerd.34,35 most studies using questionnaires might have over - estimated the prevalence of nerd because their questions might have failed to distinguish the functional heartburn.38 more precise data regarding the epidemiology of nerd are needed. in referral hospital settings, the prevalence of gerd showed wide range results as followings : 12.4%-31.7% of symptom - based gerd, 2.3%-14.7% of nerd and 7.1%-20.8% of endoscopic reflux esophagitis. in a time trend study in chinese tertiary hospitals from 2000 to 2007, the prevalence of endoscopic reflux esophagitis increased from 20.7% to 51.0% with the increased numbers of undergoing endoscopy secondary to gerd from 4.9% in 2000 to 14.1% in 2007. however, the prevalence of concomitant gerd symptoms did not significantly change (range, 13.0%-15.1%) in screening endoscopic studies with no significant interval change in the prevalence of nerd.39 therefore, those authors have suggested that the actual increase in the prevalence of endoscopic reflux esophagitis might be the result of the increased demand for endoscopic investigation of gerd symptoms in some populations, or the better recognition of reflux esophagitis by endoscopists. although typical manifestations of gerd are heartburn or acid regurgitation, atypical or extra - esophageal symptoms might also be presented including respiratory symptoms, such as chronic cough, asthma or laryngitis, dental erosions, non - cardiac chest pain (nccp), sleep disturbance and so on.40 these syndromes are usually considered to be multifactorial with gerd as one of the several potential aggravating cofactors.1 extra - esophageal syndromes rarely occur with concomitant manifestations of the typical esophageal syndrome. upper endoscopy and ambulatory ph monitoring were used to diagnose reflux in patients with atypical gastroesophageal reflux symptoms, however, these studies have been proved to have poor diagnostic yield. these data showed a wide range of prevalence or proportion because of the different definition of disease and different conditions of each study. two population - based studies in asia have demonstrated the association between extra - esophageal syndrome and gerd.41,42 the proportion of gerd was significantly higher in subjects with atypical symptoms than in controls (41.6% vs 8.7%, p < 0.05).41 symptoms as chest pain, dysphagia, globus, asthma, bronchitis, chronic cough and hoarseness were more frequently associated with gerd than controls.42 both asthma and gerd are common conditions and they often coexist. however, several western epidemiologic studies have revealed that asthma had been found more frequently in subjects with gerd than the general population.1 the prevalence of gerd was higher in the asthma group compared with controls in one large scale study (n = 1,135), performed in turkey (25.4% vs 19.4%, p < 0.05).43 the proportion of endoscopic reflux esophagitis in patients with asthma was also higher than controls.44 there have been several studies demonstrating the association between sleep disturbance and gerd. the proportion of sleep dysfunction was 52.5%-56.6% among the patients with gerd, and gerd increased the or of sleep disturbance to about twice than controls.2,45,46 dental erosion is an acid - induced loss of dental hard tissue without the involvement of bacteria. direct contact of regurgitated gastric acid is considered to be the main mechanism of dental erosion in patients with gerd.47 in tertiary hospitals, dental erosions were found in 64.5% among patients with frequent reflux symptoms (3 - 5 times / wk), 44.4% among subjects with occasional symptoms (1 - 2 times / wk) and 36.7% among controls (p < 0.05).47 nccp is a heterogeneous and complex disorder with many potential causes including gerd. nccp has been common in asia48 and gerd has also been frequently detected in nccp, even though the proportions were different according to the diagnostic modalities.48,49 barrett 's esophagus is histologically confirmed by specialized intestinal metaplasia.50,51 it is considered to be one of the most important complications of gerd due to its strong association with adenocarcinoma. however, epidemiologic studies have consistently reported that the prevalence of barrett 's esophagus - associated adenocarcinoma is very rare in asia.52,53 the prevalence of barrett 's esophagus was reported as 0.06%-0.84%29,54 in medical check - up and 0.31%-2.00%39,55 - 60 in the referral hospital settings (table 5). the proportion of barrett 's esophagus was 7.3%61 in patients with gerd and 2.4%62 in those with heartburn symptoms. importantly, esophageal adenocarcinoma is often found even without any medical history of reflux symptoms.63 although gerd symptoms is considered to be one of the most important risk factors of barrett 's esophagus,54 - 56 only 60.1% of subjects who had received the medical check - up were found to have gerd symptoms.57 in the western world, esophageal adenocarcinoma has become one of the increasing cancers, in parallel with the increased prevalence of gerd and its major determinant, obesity.64,65 such increase in the occurrence of barrett 's esophagus has not yet been observed in asia. epidemiologic changes of gerd in asia seem to be correlated with economic or environmental effects, helicobacter pylori infections, nutritional changes, and also the geographic and ethnic differences.53,66 the general low - fat diet of asian, their smaller body mass and also their higher prevalence of helicobacter pylori might be related with the lower prevalence of gerd compared to western peoples.53 however, their rapid economic growth, changes of eating habits and also the growing number of obesity in people would induce many changes in the epidemiology of barrett 's esophagus and esophageal adenocarcinoma in the future. in conclusion, many robust studies about gerd in asia have been published during recent decades. population - based studies showed that the prevalence of gerd has been increased in eastern asia, but still lower than those of the western population. the prevalence of gerd in southeast and western asia was higher than in eastern asia. the prevalence of endoscopic reflux esophagitis in eastern asia seemed to increase in participants who have received the medical check - up. in asia, only few and limited studies have been reported regarding the proportion of extra - esophageal syndromes such as asthma, sleep disturbance, non - cardiac chest pain and dental erosion, which was found to be significantly higher in the gerd patient group than controls. on the other hand, based on the distinct genetic characteristics compared from the western people, and rapid changes of socio - economic environments, this kind of study observing and investigating the epidemiologic changes of gerd in asia would be a good model to understand the underlying pathogenesis of gerd. | ethnic and geographical differences are important factors in studying disease frequencies, because they may highlight the environmental or genetic influences in the etiology. we retrieved the studies which have been published regarding the epidemiologic features of gastroesophageal reflux disease (gerd) in asia, based on the definitions of gerd, study settings, publication years and geographical regions. from the population - based studies, the prevalence of symptom - based gerd in eastern asia was found to be 2.5%-4.8% before 2005 and 5.2%-8.5% from 2005 to 2010. in southeast and western asia, it was 6.3%-18.3% after 2005, which was much higher than those in eastern asia. there were robust epidemiologic data of endoscopic reflux esophagitis in medical check - up participants. the prevalence of endoscopic reflux esophagitis in eastern asia increased from 3.4%-5.0% before 2000, to 4.3%-15.7% after 2005. although there were only limited studies, the prevalence of extra - esophageal syndromes in asia was higher in gerd group than in controls. the prevalence of barrett 's esophagus was 0.06%-0.84% in the health check - up participants, whereas it was 0.31%-2.00% in the referral hospital settings. in summary, the prevalence of symptom - based gerd and endoscopic reflux esophagitis has increased in asian countries. however, the prevalence of barrett 's esophagus in asia has not changed and also still rare. |
adverse drug reaction (adr) is defined as a response to a medicine, which is noxious, unwanted or harmful, and unintended, and which occurs at doses normally used in human for the prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function.1 incidences of adverse reactions to drugs are widespread across populations and globally, vaccines and antibiotics are among the leading causes of these reactions.2345 in addition to antibiotics, herbal medicines and antimalarial drugs have contributed significantly to adrs in nigeria.2 although developed countries have established monitoring systems that readily identify, report, and rapidly respond to adr, it is not so in some developing countries like nigeria, where data on the prevalence of adverse reactions to drugs in the population still is scanty.67 studies have established the occurrence of sulphonamide - induced hypersensitivity reactions when used,8910 and among antibiotics, sulphonamides have been reported to have a higher prevalence of adverse reactions.1112 these sulphonamide hypersensitivity reactions are majorly dermatological in expressions such as pruritus, fixed drug eruptions, maculopapular rash, and the life - threatening steven johnson syndrome.1314 acquisition of epidemiologic data can supply information concerning the prevalence of drug hypersensitivity. being a female, presence of concomitant infections (hiv, herpes), self - medications, and concurrent illnesses (systemic lupus erythematosus) have been identified as significant risk factors 1415 in some populations. in resource - poor economies, such factors could include economic status of the individual, educational exposure, and drug purchasing outlets.7 studies on identification and documentation of adrs have majorly been carried out either in hospitalized patients, among medical health professionals, students undergoing one form of medical training or within university communities.271316 very little information exists on adrs identification and/or reporting among semiurban and/or rural communities, and among individuals who are relatively educationally disadvantaged (illiterates).17 this study which was carried out in study sites across urban, semi - urban, and rural lifestyles was with the objective of determining the prevalence of sulphonamide hypersensitivity and associated sociodemographic factors within a subpopulation in nigeria ; a country where the practice of self - medication is still high and where control over prescription medicines (such as sulphonamides) is still slack.1618 the study (protocol number ui / ec/10/0021) was approved by the university of ibadan / university college hospital institutional review board. confidentially of data was ensured as interviews were conducted privately and only participants who gave informed consents were interviewed. participants signed a written consent to participate in the study, accompanied with an introductory letter that was in accordance with the declaration of helsinki. the study design was cross - sectional with participants selected from three residential categories : urban, semiurban, and rural settlements within ido local government area in ibadan metropolis. participants for this study were adult residents drawn from different communities, educational levels, and works of life. for effective community entry, the services of a trained community mobilizer from the department of public health, college of medicine, ui, was employed. in the urban areas, mobilization of eligible participants for the study was via the landlord associations of the selected residential areas while at the semi - urban and rural areas, mobilization was through the local chiefs and their governing council. a structured questionnaire was designed and pretested in two separate groups of 20 persons each tested twice within a space of 2 weeks apart. the questionnaire consisted of questions on observed sulphonamide hypersensitivity reactions (such as itching, skin rash or hives [urticaria ], scaling and/or peeling of the skin, joint pain, changes in vision, difficulty in movement, redness of skin or lips, fever, difficulty in breathing, or sore throat, following drug intake without any other reason), the name of the culprit drug, and time and duration of the reaction. it also included questions on knowledge of the respondent 's familiarity with drugs and their usage, drug purchasing sources, and mode of obtaining prescriptions. response to history of previous reaction to sulphonamides was based on participants self - report. the period of recall of ingestion of sulphonamides was limited to 2 months prior to the study period. the questionnaires also contained demographic information as well as additional data on the educational status, monthly income, and current employment status. the questionnaire was administered by trained interviewers and every interview was conducted on a one - on - one basis to ensure confidentiality. moreover, samples of the drugs (both branded and generics) were shown to respondents to ease recognition. for respondents who could not communicate effectively in english language, responses were coded, entered into a computer, and doubled checked to ensure completeness and consistency. some questionnaire items containing too many responses were re - coded into meaningful groups appropriate for the type of analysis performed. chi - square test was used to assess the association of sulphonamide hypersensitivity with sociodemographic characteristics of the participants, participant 's knowledge of drugs, and sources of drugs. variables found to be significantly associated with adrs were further investigated using multiple logistic regressions analysis. all analyses were performed at 95% level of significance using the statistical package for social science (spss) version 20. majority of the respondents (62.9%) were females while 37.1% of them were males [table 1 ]. although < 6% of the study population were teenagers, majority of them (57.3%) were < 40 years old. more than 80% of the respondents had at least primary education while < 20% of them reported that they had no formal education. sociodemographic characteristics of respondents ignorance of drug knowledge was high with more than half (63.3%) of the respondents acknowledging that they had little information on proper drug usage and administration [table 2 ]. given a memory recall time frame of not more than 2 months prior to the study time, it was observed that use of antibiotics (40.1%) and antimalarial drugs (45.7%) were common among participants. common classes of antibiotics used included sulphonamides, penicillins, and fluoroquinolones while the antimalarials having the artemisinin combinations therapies ranked highest. knowledge of drugs, sources, and side effects furthermore, although most (43.3%) of the respondents reported that they obtained their drugs from hospitals / clinics, many (23.4%) still confessed to have purchased their drugs from the open market / patent medicine store. overall, 15.5% of the participants reported to have experienced adrs to sulphonamide drugs. in figure 1, skin reactions were the predominant adrs experienced by most participants irrespective of the type of antibiotics used. however, most of those who used sulphonamides were respondents who admitted to be ignorant of drugs and drug use while the majority of those who used penicillins and fluoroquinolones were respondents who claimed to be very knowledgeable about drugs [figure 2 ]. adverse drug reactions among participants using different antibiotics participants ' level of drug knowledge and use of antibiotics in table 3, the proportion of the study participants reporting adrs was significantly higher among respondents with tertiary education (23.1%) than any other level of education (p = 0.008). in addition, the proportion of the study participants reporting adrs was significantly higher among those who claimed to be knowledgeable about drugs (27%, p < 0.001). investigating factors associated with drugs side effect using chi - square test for the adjusted logistic regression [table 4 ], the odds of reporting adrs to sulphonamides was lower among respondents who had primary (odds ratio [or ] : 0.42 ; 95% confidence interval [ci ] : 0.200.88) and secondary (or : 0.43 ; 95% ci : 0240.78) education compared to respondents with tertiary education. on the other hand, the odds of reporting adrs to sulphonamides were higher among individuals who were very knowledgeable about drug use (or : 2.07 ; 95% ci : 1.153.73), and persons who got drugs from hospitals (or : 2.00 ; 95% ci : 1.103.65) compared to those who were ignorant about drugs and those who purchased drugs from open markets, respectively [table 4 ]. evaluating the likelihood of experiencing drug side effects among participants this study investigated the prevalence of self - reported sulphonamide hypersensitivity in respondent residents across urban, semiurban, and rural communities in ido local government area, ibadan, nigeria. although most adrs studies are clinic / hospital based, this community - based study contributes unique information on the prevalence of sulphonamide hypersensitivity in the studied populations. important in our study is the high prevalence of sulphonamide hypersensitivity which is over 5 times what is reported for healthy caucasian populations19 and a quarter of what obtains in hiv / aids patients.20 this reveals a marked difference between our african (nigerian) population and caucasians, possibly serving as a pointer for evidence - based treatment of concurrent diseases in the studied populations. it was observed that despite increased bacterial resistance to sulphonamides and availability of effective alternatives which over time have narrowed the use of sulphonamides as first - line treatments for infections, the drugs are still highly used in nigeria. likely factors encouraging the increased use of sulphonamides within the nigerian healthcare system could be the use of outdated treatment guidelines, high cost of pharmaceutical alternatives to sulphonamides, and restricted access to these alternatives. accessibility to alternative drugs is restricted because they are mostly available in registered pharmacies and can not be purchased without a valid prescription.2021 this relatively high incidence of sulphonamide hypersensitivity, possibly calls for a need to review our current drug policies so that drugs that are potential candidates for adrs are either discontinued for better options or banned from use.22 sulphonamides are employed as anti - infectives, and although they are meant to be prescription - only - medications (pom), they can readily be purchased as an over - the - counter medication in nigeria. this makes them prime targets for drug misuse and/or abuse.21 patronage of open drug markets or patent medicine stores for pom is undoubtedly high as attested to from the results obtained in this study. the attendant danger with this is increased opportunities for circulation of counterfeit / fake / substandard drugs which are candidates for drug toxicities in vivo, leading to adrs in unsuspecting individuals.23 unfortunately, drug handlers at the level of patent medicine stores and/or open drug markets lack the professional expertise required for proper identification, distribution, storage, and dispensing of medications. the drug regulatory authority in the nation - national agency for food drug, administration and control (nafdac)- continues to invest much into public enlightenment on safe use of drugs which has helped to reduce the circulation of counterfeit drugs by over80% from what it was in 2001.21 however, much still needs to be done to safeguard the populace from patronising unregistered drug sources, most especially for poms. we found that education (level of literacy) informs people 's cognisance of incidences of adrs in their drug usage. in particular, we observed that participants who had no formal education, only primary education, and those who had secondary education were less likely to report the incidence of adrs than those who have tertiary education. most tertiary institutions in nigeria run a general studies program that encompasses topics across all disciplines such that graduates have basic information in all spheres of life. one of such topics is on drugs and its use in mankind, which gives a general overview necessary to raise awareness in individuals about adrs.24 such level of awareness / education could be responsible for the majority of the reported cases of adrs among individuals with tertiary education. underreporting of adrs in health institutions in nigeria is still an issue 252627 probably because poor knowledge of drugs and their uses may account for individuals not being pharmacovigilant enough to recognize an undesired effect as a drug - induced adverse effect and so may not report it.19 it is advantageous for individuals to recognize drugs they respond adversely to and so avoid them, but the possibility of re - exposure to the same drugs without relating the adverse effects suffered is very high.19 to this end, the national pharmacovigilance centre was instituted by nafdac to educate stakeholders on drug safety issues, promote rational use of drugs, and to promote spontaneous reporting of adrs to appropriate health authorities. unfortunately, data on the efficiency of these activities in the general population is unavailable. in our study, it is surprising to note that a significant proportion of those who suffered an adrs after taking a sulphonamide still repeated the intake of the drug at some later time. being economically buoyant guarantees increase in purchasing strength, especially if the desired product is available and affordable. these properties (availability and affordability) of sulphonamides, coupled with their efficacy in the treatment of infectious diseases possibly accounts for the strong association between employment status and sulphonamide hypersensitivity. ahigher percentage of the study population is employed and (most sulphonamide drugs sell for < $ 2) so can afford the drug and are therefore more exposed to experiencing adr. a major limitation of this study is the fact that adrs was self - reported. although we admit that physician - reported adrs information may provide professional data, many adrs occurring at the community level in these settings often go unreported due to both unawareness and lack of access to well - structured health reporting systems. astudy in locations with fairly uniform ethnic distributions would have provided clearer ethnic / cultural dimensions to adr. some unpredictable selection or recall biases might have also affected the generalizability of our findings ; respondents possibly might have thought of some symptoms as being insignificant or irrelevant to the study objectives. although we limited recall period to not more than 2 months before the study time and also took along many sample packs of the culprit drugs, reports in cross - sectional studies are known to largely depend on the accuracy of the respondents. notwithstanding, adequate efforts were made to present accurate and comprehensive reports in this study sufficient as a scientific evidence to inform policy and further study directions on the subject. a major limitation of this study is the fact that adrs was self - reported. although we admit that physician - reported adrs information may provide professional data, many adrs occurring at the community level in these settings often go unreported due to both unawareness and lack of access to well - structured health reporting systems. astudy in locations with fairly uniform ethnic distributions would have provided clearer ethnic / cultural dimensions to adr. some unpredictable selection or recall biases might have also affected the generalizability of our findings ; respondents possibly might have thought of some symptoms as being insignificant or irrelevant to the study objectives. although we limited recall period to not more than 2 months before the study time and also took along many sample packs of the culprit drugs, reports in cross - sectional studies are known to largely depend on the accuracy of the respondents. notwithstanding, adequate efforts were made to present accurate and comprehensive reports in this study sufficient as a scientific evidence to inform policy and further study directions on the subject. purchasing of drugs from the open market, level of literacy, ethnicity, and knowledge of drug use are factors associated with adrs to sulphonamides in the studied area. in obtaining a complete adrs information, | background : documentation of adverse drug reactions (adrs) is critical to a safe health delivery system. the aim of our study was to explore the prevalence of self - reported sulphonamide hypersensitivity reactions in a community - based sample of the general population in ibadan, nigeria. we also examined sociodemographic factors associated with adrs in the sample.patients and methods : the study was cross - sectional in design with study sites in urban, semiurban, and rural settlement areas. pretested questionnaires were administered on a one - on - one basis by trained interviewers. frequency tables and percentages were computed for various levels of the variables. chi - square test was used to assess the relationship between sulphonamide hypersensitivity and variables such as sociodemographic characteristics of respondents, respondents ' knowledge of drugs, as well as drug sources. variables found to be significantly associated with sulphonamide hypersensitivity were further investigated using multiple logistic regressions analysis.results:out of the 1062 respondents, 15.5% reported hypersensitivity to sulphonamides with skin reactions being the most prevalent. the proportion reporting adrs was significantly higher among respondents with tertiary education (23.1%) than any other level of education (p = 0.008). in addition, individuals who were very knowledgeable about drug use (odds ratio[or ] : 2.07 ; 95% confidence interval [ci ] : 1.153.73) and persons who got drugs from hospitals (or : 2.00 ; 95% ci : 1.103.65) were more likely to report adrs than those who were ignorant about drugs and those who purchased drugs from open markets, respectively.conclusion:prevalence of sulphonamide hypersensitivity is high among respondents, and adrs is likely to be reported by people who are knowledgeable about drug use. |
bacterial pathogens predominantly respond to environmental changes, such as entry into a host, by adapting their physiology through altered gene expression. the gene products that give a pathogen an enhanced chance of survival within the host are termed virulence factors. pathogens use a variety of different mechanisms to regulate virulence gene expression. besides transcriptional control, several post - transcriptional mechanisms have been well documented in the literature [1, 2 ]. in the recent years, messenger rna (mrna) stability emerges as a major player controlling the expression levels of proteins that allow pathogenic bacteria to thrive within the host. the stability of mrna is dictated by the activity of ribonucleases (rnases) that act either alone or in the presence of small regulatory rnas (srnas) and/or with ancillary proteins. the stability of mrna also depends on growth stage, environmental cues, or stresses (such as the presence of nutrients, metabolites) as well as cell - density, a phenomenon known as quorum sensing [3, 4 ]. the cell can directly control global rna decay by adjusting the levels of rnases [4, 5 ]. studies using escherichia coli and bacillus subtilis have given a detailed knowledge about the mechanisms of rna decay and maturation for gram - negative and gram - positive bacteria [6, 7 ]. for instance, posttranscriptional control mediated by srnas and rnases is particularly important as it provides the cell with a means to adapt rapidly to sudden environmental changes and stresses. moreover, it is energetically less costly as it bypasses the need for new protein synthesis. additionally, fast removal of the srna regulator when the stress is over allows the cell to recover and return to its previous genetic program. the advent of new technologies such as deep - sequencing and tiling arrays revealed a plethora of srnas and antisense rnas (asrnas) encoded in the bacterial genomes [811 ]. although their functions and the conditions under which they are expressed are only now starting to be understood, we expect a lot of exciting discoveries in the field of rna regulation. in this paper, we will primarily focus on rnase - mediated regulation of virulence gene expression in medically relevant gram - positive bacteria. different mechanisms will be presented showing that rnases can either activate or repress gene expression. the involvement of rnases in bacterial antiviral defense, transfer of mobile genetic elements and persistence will be presented. we discuss the genomic context within which rnases are embedded and how the conservation of patterns amongst several genomes can give us insight into their expression. perspectives on the design of new generation antibiotics targeting several components of the rna degrading machinery will be underscored. decades of research have resulted in the identification / characterization of several rnases within b. subtilis. an exhaustive overview of these is beyond the scope of this paper and we refer readers to some high - quality review articles that cover this topic [5, 7 ]. instead, with an emphasis on the most recent discoveries, we will present the works done in b. subtilis for specific rnases where homologues in pathogens have been associated with virulence. rnases are broadly divided into two groups : (1) exoribonucleases, which degrade rna substrates from either the 5 or 3end and (2) endoribonucleases that cleave internally within an rna molecule. the orchestration of mrna decay in gram - positive bacteria by the concerted action of several rnases is illustrated schematically in figure 1. recently, an essential gene within b. subtilis (ymda) was determined to be involved with rna processing and was renamed rnase y [12, 13 ]. rnase y cleaves unpaired regions of rna and subsequent work demonstrated that rnase y is the functional equivalent to rnase e in e. coli, the major single - strand specific endoribonuclease which initiates rna processing and degradation. interestingly, changes in expression levels of rnase y within b. subtilis resulted in altered stability of polycistronic mrnas required for biofilm formation, but this phenotype may be attributed to a polar effect on expression of the downstream gene, ymdb, which has been shown to be required for biofilm formation. rnase y was reported to be involved in riboswitch turnover, as well as to affect global mrna decay [12, 15 ]. recent data from distant bacteria show that rnases such as e. coli rnase e and b. subtilis rnase y are not evenly distributed in the cytoplasm but that a fraction is localized at the membrane [17, 18 ]. although it is not known whether the localization is a regulated process, the transmembrane domain of rnase y is essential for the activity of the enzyme in vivo. therefore, these data suggest that rna turnover is somehow compartmentalized in the cell and that the spatial organization of rnases in bacteria is an additional layer of regulation. rnases j1 and j2 were first identified and characterized in b. subtilis as the component that endonucleolytically cleaved the thrs leader mrna. size exclusion chromatography reveals that recombinant rnase j1 from b. subtilis elutes as both a homodimer and a tetramer. rnases j1/j2 are bifunctional and possess both endoribonuclease and 53 exoribonuclease activities [19, 22 ]. additionally, these two proteins can form a heterodimeric complex that has unique cleavage site specificities and efficiency. the exoribonuclease activity of rnase j2 has been shown to be significantly less efficient compared to rnase j1. the 53 exonuclease activity, previously not identified in bacteria, appears to be the major function in vivo. it has been demonstrated that rnase j1 is involved with global rna turnover and with processing of 16s and 23s rrnas [24, 25 ]. the 5 triphosphate of primary transcripts and/or the presence of a hairpin structure at the 5 end protect rna from degradation by the exoribonuclease activity of rnase j1 [22, 26 ]. rnases j1/j2 have been found associated with the gram - positive degradosome complex [13, 27 ] (discussed below). the protein consists of three domains, a core -lactamase domain, a -casp domain, that is specific to members of the -lactamase superfamily of enzymes acting on nucleic acids, and a unique c - terminal domain, that is joined by a flexible linker to the -lactamase domain. two catalytic zinc (zn) ions were found in a cleft between the -lactamase and -casp domains. however, this structure, bound to a ump substrate, appeared to be in a closed conformation that could not explain the 5 monophosphate substrate preference nor did it reveal the mechanism for the dual - enzyme activities. the structure of a catalytically inactive mutant form of rnase j1 associated with a 4 nt rna sequence has recently provided new insights for the mechanisms of the dual enzymatic activities and rna binding. the binding of the rna induces a change in the relative position of the three domains with respect to each other as well as specific alterations in conformation of the specific -casp and -lactamase domains. these movements result in a widening of the narrow catalytic cleft between the domains creating a channel that is wide enough for a single - stranded rna to enter. the cleaved nucleotide is discharged from the other side through a negatively charged exit tunnel. the binding of rna causes major rearrangements within the -casp domain where specific loop regions are displaced by up to 12 to accommodate the substrate. the rna binding pocket consists of positively charged residues that extend beyond the cleavage site, giving a rationale for the binding of longer rna transcripts and the endoribonucleolytic activity. the recently solved structure and modeling of b. subtilis rnase j1 has revealed a similar pattern of conformational changes upon substrate binding. in b. subtilis, the nonessential multifunctional pnpase (77 kda) is the major exonucleolytic rnase, that forms a trimer to catalyze the 3 to 5 phosphorolytic degradation of rna [2931 ]. additionally, under certain conditions, pnpase is able to add nucleotides to the 3 end of rna. the 3 binding and processivity of pnpase appear to be blocked by strong hairpin secondary structures such as rho - independent terminators, which are often found at the ends of b. subtilis transcripts and the processivity was inhibited by the not i sequence (gcggccgc). thus, it is believed that pnpase plays the secondary step in rna decay and that the degradation of nucleotides only occurs after the 3 end becomes exposed due to an endonucleolytic cleavage by another rnase (rnase iii, rnase y, or rnase j1/j2). it is interesting to mention some of the remarkable new functions discovered involving this versatile protein. recently, pnpase was found to copurify with b. subtilis recn and this complex was able to degrade single - stranded dna (ssdna) in vitro. the exonucleolytic activity of pnpase on ssdna was characterized and a functional role for pnpase in homologous dna recombination in b. subtilis was identified. extending from this work the same group was able to show that b. subtilis pnpase catalyzes template - independent polymerization of dndps onto 3 ends of ssdna. this work has led to the establishment of a molecular model for the role of pnpase in dna repair. bacterial rnase iii belongs to the class i rnase iii family of enzymes, while classes ii and iii include the eukaryotic drosha and dicer, respectively, which are involved in biogenesis of sirna / mirna in higher organisms (reviewed in [3, 36, 37 ]). the bacterial rnase iii is the smallest of rnase iii family members consisting of a catalytic and a dsrna binding domain., a fourth class of rnase iii enzymes was found with the discovery of the endoribonuclease mini iii, which is involved with the final steps of maturation of 23s rrna. this enzyme lacks three out of four dsrna binding domains and consists of only the catalytic domain. the structures of bacterial as well as eukaryotic rnase iii enzymes have helped in understanding their functions (reviewed in). rnase iii is a mg - dependent double - strand - specific endoribonuclease capable of cleaving dsrna. it recognizes a variety of structures such as imperfect duplexes, helices interrupted by bulged residues, kissing loops, and stacked helices [4144 ]. cleavage by rnase iii produces the characteristic type of dsrna with a 5 phosphate and a 3 hydroxyl group and a 2 nt 3-overhang (reviewed in [57 ]). rnase iii is involved in the maturation of large ribosomal rnas in e. coli and b. subtilis as well as in the regulation of single and polycistronic mrnas [57, 46 ]. moreover, it is involved in the maturation of other housekeeping rnas such as the small cytoplasmic rna (scrna) precursor in b. subtilis [4749 ]. no consensus sequence motif has been defined for this enzyme but antideterminants have been proposed to prevent the recognition of rna molecules by e. coli rnase iii. rnase p is a ribonucleoprotein particle that contains at least one protein subunit and a single - ribozyme subunit. in b. subtilis, rnase p has been shown to cleave precursor trnas and tmrna forming the mature 5 end and to cleave the adenine riboswitch which stabilizes the downstream mrna transcript [52, 53 ]. crystal structures of rnase p either alone or bound to trna reveal that the rna - rna recognition occurs through shape complementarity and conserved intermolecular contacts. the active site structure and the conserved rnase p - trna contacts suggest a universal mechanism for catalysis. since biochemical and structural mechanisms for recognition and cleavage of rna substrates by rnase p have been characterized in - depth by several groups, we refer the readers to an excellent recent review for a comprehensive summary of this work. in e. coli, rna pyrophosphohydrolase (rpph) removes a pyrophosphate from the 5 end of rna, converting the triphosphate into a monophosphate, a reaction that occurs before rna degradation by rnase e. the finding that a 5 triphosphate on rna is a poor substrate for rnase j1/2 in b. subtilis inspired richards. to search for the functional rpph homologues in b. subtilis. bioinformatic searches identified six putative homologues with canonical nudix hydrolase motifs. to identify the functional rpph, they identified an rpph - dependent b. subtilis transcript by constructing a rrph strain and screening for mrnas with altered half - lives. detailed study of the processing of a polycistronic mrna reveals that rpph converts the 5 triphosphate to a monophosphate mrna prior to degradation by rnase j1. even though the rpph has not yet been implicated in virulence, this discovery reveals an additional stage in the elegant orchestration of rna decay. while screening for in vivo interaction partners of glycolytic enzymes within b. subtilis, several proteins known to be involved with rna processing and degradation were identified. the primary protein - protein interactions were further evaluated using the bacterial two - hybrid approach. the gram - positive degradosome consists of three rnases (rnase j1/j2, rnase y), polynucleotide phosphorylase (pnpa) and two glycolytic enzymes (phosphofructokinase and enolase). further characterization identified a dead box rna helicase (csha) that interacts with rnase y and pnpa. this helicase was predicted to be localized at the membrane since the protein carries a n - terminal transmembrane domain similar to the sequence present on rnase y. recently, the degradosome from s. aureus has been characterized and evaluated using the bacterial two - hybrid approach. although this work confirmed the conservation of the b. subtilis multienzymatic complex, different partner interactions were described and additionally, the association of the protein subunit of ribonuclease p (rnpa) with csha was demonstrated. the importance of genomic organization and operon structure for gene expression has been well documented. often genes with similar function or associated to the same biosynthetic pathway tend to be found within the same operon or in close proximity on the chromosome. combining genomic information from several public databases (ncbi, genolist, and biocyc.org), we analyzed the conservation of genetic organization across four families of pathogenic gram - positive bacteria additionally including b. subtilis. using the multigenome alignment tool (http://www.biocyc.org/), the genomic context was aligned for several gram - positive organisms (see figures 18 in supplementary material available online at doi : 10.1155/2012/592196). several of the genes (pnpa, rnjb, rny) for the proteins involved in the degradosome are located in a relative close proximity to each other on the chromosome and genetic arrangements appear to have evolved in gram - positive species (figure 3). however, a loose conservation of pnpa - rnjb - rny gene cluster is observed among the genomes. interestingly, the presence of rpso upstream of pnpa is found in all genomes and in e. coli as well, suggesting that pnpa and rpso are ancient genes of a common origin. in b. subtilis, pnpa is part of a polycistronic operon located 8 kb upstream of rnjb, and the rnjb operon is sandwiched between two chromosomal regions that contain several sporulation genes. in s. aureus, pnpa and rnjb are located directly next to each other (figure 3). in clostridia species, no rnase j2 homologue was found, but a large genomic rearrangement has brought pnpa relatively close to rny. in listeria species, a very different genomic context is observed, where large genomic insertions separate the genes of this cluster. the proximity of pnpa - rnjb - rny locus within several gram - positive organisms may have functional consequences. for instance, located within the same locus are certain genes that have been identified to cross - regulate expression and activity. the enzymatic activity of pnpase on single - stranded dna is in part modulated by reca, a gene located upstream of rny. decay of the highly conserved rpso mrna is initiated by rnase y followed by pnpase. recently, in streptomyces coelicolor, it has been shown that transcripts originating at the rpso promoter read - through into pnpa and become processed by rnase iii. the clustering of rnase genes, along with several genes for sporulation, cell wall peptidoglycan biosynthesis, motility, and cell division are also noteworthy. in e. faecalis, cotranscribed with rnjb are two genes involved with cell wall biosynthesis and rnjb has been shown to regulate pili formation at the posttranscriptional level. in b. subtilis, rnase y (rny / ymda) is the first gene of a bicistronic operon including ymdb which was recently shown to play a critical role in the bistable expression of genes involved in flagella and biofilm formation. moreover, the genes located upstream of rny, pgsa (cell wall biosynthesis), cina (competence - damage inducible regulator), and reca (member of sos regulon) are relatively conserved among gram - positive bacteria. the gene encoding csha, the rna helicase of the degradosome in b. subtilis, is also part of an operon including two genes encoding proteins involved in peptidoglycan biosynthesis. the genomic context of this operon is conserved in other species (see supplementary figure 8). rnase iii (rnc) is transcribed as the first of a three - gene operon in b. subtilis, also encoding the essential smc (chromosome condensation and segregation atpase) and ftsy (signal recognition particle). this organization is also highly conserved in all gram - positive species (see supplementary figure 2). transcriptomic array data for s. aureus [74, 75 ] reveal that all rnases are expressed in vegetative growth. at the transition to stationary phase, the levels either (i) drop dramatically and remain low thereafter for rnase j2, rnase y, and rnase p or (ii) reduce slightly only to catch back later into stationary phase for rnase j1, pnpase, and rnase iii. the reduced transcript levels of several s. aureus rnases in stationary phase [74, 75 ] appear to correlate with the demand for peptidoglycan / ribosome biosynthesis. the role of several rnases in virulence has been recently studied in two major pathogenic bacteria, streptococcus pyogenes and staphylococcus aureus. s. pyogenes (group a streptococci, gas) and s. aureus cause mild to systemic and life threatening diseases. the emergence of methicillin resistant s. aureus strains acquired both in hospitals and, in the community, has resulted in more deaths annually than hiv in the united states in recent years [76, 77 ]. gas transcripts have been recently classified into two classes, i and ii, depending on their stability during stationary phase of growth. class i transcripts appear very labile during stationary phase, while class ii transcripts encoding several virulence factors such as saga (streptolysin s), sda (dnase), and arc (arginine deiminase) have prolonged half - lives. it has been shown that the 35 exonucleolytic activity of pnpase is responsible for degrading substrates of class ii after an elongated lag phase where mrnas are stable. the initial endoribonucleolytic cleavage of classes i and ii transcripts is mediated by rnases j1 and j2, which are essential in gas [78, 80 ]. it was proposed that class i transcripts are better substrates for rnases j1 and j2 and only after their depletion, degradation of class ii transcripts is initiated. the amounts of rnases j1, j2, and pnpase as well as putative signals they respond to, might be critical for such growth phase - dependent regulation. rnase y, encoded by cvfa in streptococcus and staphylococcus, has been shown to affect virulence in both pathogenic bacteria in silkworm and murine models [8183 ]. in s. pyogenes, a cvfa deletion affected expression of several virulence factors. moreover, microarray analysis revealed differential expression of 29% of genes indicative of the importance of rnase y in the initiation of mrna decay. these data suggested that rnase y mediated downregulation of metabolism and upregulation of certain virulence factors facilitates the acquisition of cellular components from the host. the effect of rnase y on virulence gene expression occurred mainly in stationary phase in agreement with data showing that virulence factor expression in s. pyogenes is strictly dependent on growth phase. rnase y - mediated regulation was shown to be dependent on the nutritional status of the cells implying that the enzyme is involved is sensing the nutrient availability (directly or indirectly). however, its deletion did not affect the ppgpp levels, therefore the observed effects were not linked to stringent response. s. pyogenes rnase y interacts with the glycolytic enzyme enolase which might provide a link between nutritional status and rnase y - mediated gene expression. rnase y has been reported to affect production of virulence factors in s. aureus either through expression of the accessory gene regulatory locus, agr or independently. biochemical analyses revealed that the predicted phosphohydrolase domain (hd domain) of rnase y possesses a phosphodiesterase activity against 2, 3-cyclic nucleotide and this activity is required for virulence. rnase y was predicted to contain a transmembrane domain in s. pyogenes and s. aureus [82, 83 ], similar to the b. subtilis enzyme. studies have indicated that the capacity of s. aureus to differentially express subsets of virulence factors according to stress and growth phase is largely attributed to mrna stability. in particular, it was shown that mrna stabilization occurs in stationary phase as well as under cold-, heat-, acid-, and alkaline - shock and the stringent response [85, 86 ]. the authors showed that pnpase affected bulk mrna decay and was shown to be essential for cold - growth as is the case for e. coli, salmonella enteric, and several yersinia species (reviewed in). in addition, rnase p was also described as a major rnase involved in bulk mrna degradation that has direct consequences on the expression of virulence factors at the stationary phase of growth. the activation of an s. pyogenes mrna encoding a virulence factor (ska, streptokinase) depends on the presence of a srna, fasx. fasx binds to ska mrna 30 nts upstream of the aug and forms a 7 nts - long helix. this double - stranded structure leads to an increased stability of the mrna (figure 2(a)). notably, a c - rich sequence motif present on fasx is employed for the interaction, similarly to what has been described for s. aureus rnaiii and other srnas [71, 88 ]. deletion of either rnase y or pnpase did not result in stabilization of ska mrna indicating that fasx - dependent stabilization is due to a limited access of rnases at the 5-end. whether the 5-3 exoribonucleolytic property of rnases j1 and j2 is responsible for ska mrna degradation, remains to be tested. within clostridium perfringens, the virr / virs two - component system regulates several virulence genes including transcription of the 386 nts srna, vr - rna. recent work by obana. has shed light onto the vr - rna - dependent regulation of the toxin collagenase (cola). base pairing of vr - rna with the 5utr of cola mrna induces cleavage by an unknown rnase immediately downstream of the cola - vr - rna duplex. this processing in turn leads to the formation of a shorter hairpin and increased mrna stability in vivo. mutational analysis of the rbs indicates that ribosome binding to the processed mrna additionally stabilizes the cola mrna. hence, the secondary structure of mrna has an important role in controlling transcript stability as highlighted by the two examples for ska and cola mrnas [70, 90 ]. interestingly we have shown that in s. aureus, rnase iii mediates transcript stabilization of cspa mrna, encoding a cold - shock protein, through processing of a long hairpin structure in the 5utr. this processing leads to the formation of a short but stable hairpin that enhances the stability of the mrna and its translation (lioliou., recently, gao. showed that the e. faecalis rnjb, encoding rnase j2, is involved in the regulation of pilus gene expression and biofilm formation. the mechanism of action by which rnase j2 stabilizes the mrna and whether this regulation takes place in other gram - positive bacteria producing pili remains to be shown. the effect of rnase iii in virulence in s. aureus has been well documented. specifically, in stationary phase, rnase iii acts together with the agr encoded regulatory rnaiii to repress the expression of several adhesin factors and the repressor of toxins, rot [44, 71, 72 ]. rnaiii is a multifunctional rna that encodes a virulence factor, hemolysin delta. through its 3 utr, rnaiii interacts with mrnas either by forming imperfect duplexes or by promoting the formation of loop - loop interactions. in cases where translational rnaiii - mrna complexes in turn constitute targets for rnase iii cleavage to render regulation irreversible (figure 2(b)). translational repression of rot indirectly results in the activation of toxins and in the repression of adherence factors. as more functions of regulatory rnas are unveiled [8, 88, 9496 ], it is predicted that other srnas, such as the group i toxin - antitoxin systems, might act coordinately with rnase iii to regulate gene expression. in a recent report, it was shown that a rnc strain was attenuated in a murine infection model, and that rnase iii is involved in the regulation of extracellular protein secretion, such as the extracellular fibrinogen binding protein efb in s. aureus. this was achieved through regulation of the levels of secy2 mrna encoding a protein of the accessory secretory system. in gram - negative bacteria, hfq has been shown to be a critical component of srna - mediated regulation. evidence of a similar role for hfq in gram - positive bacteria has remained elusive until recently.. showed that within listeria monocytogenes, translational regulation of lmo0850 mrna mediated by the binding of lhra srna is dependent on hfq. the specific rnases involved in the degradation of the lmo0850 transcript still remain to be determined. additionally, a lhra deletion within l. monocytogenes altered the expression levels of approximately 300 genes, including chia, a known virulence factor that encodes a chitinase. recently, the role of rnase iii in bacterial immunity against phages and plasmids has been demonstrated. crispr / cas (clustered, regularly interspaced short palindromic repeats / crisp - associated proteins) systems mediate bacterial immunity against foreign invading dna, such as plasmid and phages. the crispr genetic loci encode for spacer - repeat sequences as well as their associated cas endoribonucleases. the repeat sequence is usually identical and can be found between 2249 times within a locus. the spacer sequences are unique and originate from phage or plasmid sequences that have been integrated in the genome and which subsequently confer immunity against the specific phage or against plasmid conjugation [103107 ]. the crispr loci are transcribed as a long pre - crrna, which is then matured into small rnas (crrna) consisting of a single spacer - repeat unit, which effectively attacks foreign dna. however, some cas homologues are absent from certain subtypes of crispr systems as in s. pyogenes, which lacks three cas proteins, cse3 (case), cas6, and csy4. in these cases, the host - encoded rnase iii mediates maturation of the pre - crrna acting in concert with a trans - encoded rna (trans - activating crispr rna, tracrrna) and the endoribonuclease csn1. particularly, it has been reported that tracrrna interacts with almost perfect complementarity with the repeat units in the pre - crrna. in a first processing event, rnase iii cleaves specifically the duplexes and subsequently, a second cleavage occurs in the spacer sequence. the exact mechanism underlying the second processing event and whether it is carried out by csn1 remains to be elucidated. this type of regulation was found conserved in other bacteria such as listeria innocua, neisseria meningitides, streptococcus mutans, and streptococcus thermophilus. based on examination of several bacterial genomes, it was suggested that tracrrna possibly co - evolved with the repeat sequences of crrna. riboswitches are cis - acting regulatory rna sequences that control expression of downstream genes by binding metabolites that induce structural changes to the transcript. an interesting study recently highlighted the regulatory importance of cyclic - di - gmp. in this study, a new class of c - di - gmp riboswitch was identified that is linked in tandem to an allosteric self - splicing ribozyme upstream of a putative virulence gene within the genome of clostridium difficile. binding of c - di - gmp to this rna structural motif induces folding changes at the splice site causing a different splicing pattern. the binding of c - di - gmp results in the inclusion of a perfect rbs directly upstream of a nonconventional uug translational start codon. without the second messenger signal, c - di - gmp the discovery of the mechanism for transcript destabilization induced by the glms ribozyme has demonstrated how the cell can sense nutritional status and modulate gene expression accordingly using catalytic rna cleavage followed by rnase - mediated decay. in b. subtilis, glucosamine-6-phosphate binds to the glms ribozyme stimulating site - specific rna self - cleavage in vivo. this cleavage results in transcripts that contain a 2-3 cyclic phosphate at the 3 end and a hydroxyl group at the 5 end. it was shown that targeting of glms rna for degradation was due to the 5 hydroxyl end which was a substrate for the 53 exoribonuclease activity of rnase j1. this work demonstrates that metabolite - sensing ribozymes enable the cell an efficient means to respond to their environment. their involvement in phage resistance, plasmid maintenance, stress responses, and bacterial persistence is well documented (for reviews, see [112118 ]). the antitoxin is a noncoding rna (ncrna), which is antisense to the mrna encoding the toxin. for type ii, type iii (toxin) was recently discovered and employs an antitoxic srna, which binds and inhibits a protein toxin. for type ii and iii systems, the toxin and the antitoxin are cotranscribed as part of an operon, whereas for type i systems the two genes are encoded on the opposite strands overlapping in their 5- or 3-ends. in all cases the antitoxin, rna or protein, is labile and subject to degradation, while the toxin is stable. upon conditions that favor elimination of the antitoxin, the ta complex is disrupted, and the toxin is released (or translated) to exert its toxic effect. type i toxins usually consist of small hydrophobic peptides, the translation of which is turned off by antisense rnas (asrnas). in the case of e. coli hok / sok and tisab / istr systems, rnase iii is the key enzyme which degrades the mrna - asrna complex. toxins of type ii act usually as endoribonucleases (mazf and rele) or inhibit dna gyrase (ccdb) [112114 ]. the e. coli mazf is an endoribonuclease cleaving mrnas at a defined aca consensus sequence independently of the ribosome, while rele is a ribosome - dependent endoribonuclease that cleaves mrnas positioned at the ribosomal a - site (reviewed in [112, 114 ]). the unique type iii toxin, toxn, was demonstrated to have endoribonuclease activity in vitro and was capable of cleaving its inhibitory antitoxic srna [119, 120 ]. these data suggest that toxn possibly acts as an rnase to inhibit translation and slow down bacterial growth. the only type ii ta system identified in b. subtilis so far is ndoai / ndoa where ndoa encodes the toxin (endoa, mazf homologue), which cleaves at unpaired uacau sequences, and ndoai encodes the antitoxin [121, 122 ]. depending of the nature of the stress, the ta module in b. subtilis can be protective or lethal. the authors hypothesized that this behavior would allow the cell a way to determine if the stress was mild enough to be repaired or so severe as to activate the cell death pathway. interestingly, a type i ta system encoded in the chromosome of b. subtilis was identified. pairing between txpa - rata leads to degradation of the mrna by an unknown rnase (figure 2(c)). given its specificity for dsrna, rnase iii could be a good candidate to mediate the degradation. as the number of asrnas found in bacterial genomes constantly increases [811 ], rnase iii might prove to be an important player in this type of regulation. the pemk was shown to be an endoribonuclease toxin that shares 96% similarity to the endoa (mazf homologue) toxin from b. subtilis. biochemical characterization of the ta module confirmed that pemi inhibits pemk - mediated endoribonuclease activity. the catalytic residues in pemk were defined in vitro, and surprisingly, the catalytic mutants retained the capacity to bind pemi efficiently. the pemik interaction was characterized in vitro giving clues to the conformational changes that take place following complex formation. synthetic peptides were designed to disrupt the pemi - pemk interaction and to inhibit the endoribonuclease activity of pemk, demonstrating that ta modules can be potential antimicrobial targets. the identification of mazef and to a smaller extent axe - txe, relbe, and -homologues in plasmids of vancomycin resistance enterococci (vre) isolated from patients demonstrates their clinical importance. the authors showed that the mazef system was transcribed and endowed enterococci with plasmid stability. moreover, the mazef genes were located on the same plasmid with the vancomycin resistance gene cluster, vana. recently, the axe - txe system was identified in a plasmid from enterococcus faecium, which also encoded multiple drug resistances. the system was expressed in clinical isolates and txe was shown to have endoribonucleolytic activity in vivo. the presence of these systems in enterococcal plasmids might imply a role in the transfer of antibiotic resistance genes to other species such as mrsa linking ta systems to development of virulence. mazef was also identified in s. aureus and the unpaired uacau recognition sequence for endoribonucleolytic cleavage was established [128, 129 ]. induction of mazef leads to destabilization of srap mrna which contains the consensus cleavage motif. the occurrence of the consensus sequence within coding sequences of other virulence factors was also demonstrated. the induction of the mazef had an effect on the expression of spa and hla mrnas. as mazef and sigb are transcriptionally linked, sigb expression is partially dependent on factors affecting transcription of mazef such as heat - shock and antibiotic stresses. sigb was also shown to downregulate expression of mazef, therefore creating a feedback inhibitory loop that possibly affects its own expression. these findings have significant implications in mediation of stress responses and virulence as sigb is a major regulator of these biological processes in s. aureus. recently, the expression of a chromosomally encoded mazef system in clinical isolates of mrsa strains was reported. therefore, this ta module is an important player in regulation of pathogenicity and might constitute a novel target for antibiotics. interestingly, it was recently shown that e. coli mazf cleaves preferentially aca sequences in mrnas located close by to the aug codon thus generating leaderless mrnas. in addition, the enzyme also cleaves 16s rrna within the 30s subunit and removes its last 43 nucleotides including the anti - shine and dalgarno sequence. this in turn creates a subpopulation of ribosomes that are able to translate the leaderless mrnas. whether the formation of such specialized ribosomes produced under stress conditions can be generalized to all bacteria remains to be addressed. mycobacterium tuberculosis is a major worldwide health problem and in 2009 approximately 1.7 million people were estimated to have died from tuberculosis (who, global tuberculosis control report 2011, who / htm / tb/2011.16). bioinformatic analyses revealed that m. tuberculosis encodes 88 putative ta systems, 30 of which were shown to be functional. remarkably, most of the ta systems were conserved within the m. tuberculosis complex (mtbc) while they were absent from closely related species. this implies that they were acquired after the speciation event and that they probably play a significant role in pathogenicity. the vapbc is the most abundant ta module in m. tuberculosis represented by 47 members. subsets of vapbc modules were shown to be toxic when expressed and conversely this toxicity was counteracted by coexpression of the cognate vapb antitoxin [135, 136 ]. vapc functions as an rnase in vitro and this may account for the inhibition of translation observed in vivo which profoundly affects gene expression in response to different environments and stresses [135, 136 ]. certain sets of ta systems were found upregulated under hypoxia and during infection of macrophages. previously, it was shown that the recognition sequences of mazf - mtb were less frequently present in proteins associated with pathogenicity (reviewed in). hence, certain ta modules can direct degradation of specific mrnas in response to stress rather than inhibit bulk translation. interestingly, winther and gerdes have shown that enteric vapc encodes a trnase that cleaves initiator trna between the anticodon stem and loop. cellular depletion of trna had a bacteriostatic effect on cultures and production of vapb allowed cells to resume growth. the depletion of trna by vapc not only inhibited cell growth but was additionally found to activate initiation of translation at correctly positioned elongator codons. the authors further speculated that this mechanism has the potential to translate reading frames that were normally silent. this work in enteric bacteria has significant implications for virulence in gram - positive organisms, particularly m. tuberculosis where vapbc modules are highly represented [135, 136 ]. the oxidative burst within macrophages generates superoxide anion (o2) and singlet oxygen, which can be lethal to cells. a mechanism to globally reduce translation, such as cleavage of trna, would reduce the occurrence of toxic events and enhance survivability of the organism. bacterial persistence is a phenotype where part of the cell population enters a dormant nongrowing state which in turn confers resistance to antibiotics and other stresses. the involvement of ta systems in development of persistence in e. coli was recently reported. the authors showed that overexpression of the toxin led to the persister phenotype and that successive deletion of all ta systems in e. coli resulted in a dramatic decrease in formation of persisters. consistent with involvement of ta systems in the persistence phenotype, the transcriptome of persister m. tuberculosis revealed overexpression of ta systems. abortive infection (abi) is mediated by the type iii toxin systems and constitutes another mechanism by which bacteria defend against phages. during abi, a phage - infected bacterium altruistically commits suicide to prevent the spread of phage within the population. toxin systems were identified in the gram - negative phytopathogen erwinia carotovora but homologues are found in the genomes of several gram - positive and gram - negative pathogenic bacteria. the hok / sok (type i), mazef (type ii) systems have also been shown to confer phage resistance to their hosts (reviewed in [112, 118 ]). this type of antiviral immune system could be critical for limiting horizontal transfer of phage encoded virulence factors between pathogenic species. interaction with a srna can lead to occlusion of the ribosome binding to repress translation. often an rnase is recruited to the site of interaction to degrade the mrna making the regulation irreversible. it has also been proposed that in the absence of ribosome binding, the mrna becomes more exposed to the action of rnases so that repression of translation can lead to rapid degradation [3, 5 ]. most of our knowledge on srna stability comes from gram - negative bacteria. in those cases examined, rnase iii, pnpase, and rnase e are involved in the degradation of the srna, which can be coupled or uncoupled to that of the mrna target [143146 ]. unexpectedly, srnas were recently shown to be destabilized in e. coli pnpa mutant cells in exponential phase of growth. while s. aureus rnase iii has been shown to initiate the decay of mrnas repressed by the quorum sensing dependent rnaiii, little is known on the roles of rnases associated with the srna - dependent regulation in gram - positive bacteria. in the cases described so far where regulation of mrna stability occurs through the combined action of a srna and a ribonuclease, the initial cleavage site is located within the mrna - srna duplex as it is the case for rnase iii or proximal to the base - pairing region as exemplified for rnase e [1, 6 ]. a novel mode of action for e. coli rnase e was recently reported where the enzyme acts at a distance cleaving further into the coding sequence. rnase e was found tethered to the rbs of sodb mrna through association with hfq and the srna ryhb which in turn occluded ribosome loading onto the rbs. when the mrna was stripped of translating ribosomes, rnase e cleavage sites present within the coding sequence were exposed to the endonucleolytic activity of rnase e. whether a similar mechanism exists in gram - positive bacteria, remains to be elucidated. hfq, although a major player in srna - mediated degradation in gram - negative bacteria, does not seem to have such an important role in rna decay in gram - positive bacteria with one exception reported so far (see earlier). interestingly, a conserved protein was found in sinorhizobium meliloti, smc01113/ybey, which shares structural similarities with the mid domain of the argonaute (ago) proteins. this protein is conserved in gram - positive bacteria although its function has not yet been studied in these organisms. in b. subtilis, three small basic proteins were proposed to act as rna chaperones acting in concert with the srna fsra, to promote degradation of transcripts encoding iron - using proteins under conditions of iron deprivation. hence, these examples illustrate the important role of rnases in mrna turnover and gene regulation and show that repression of translation mediated by srna (also by translational repressor proteins) is often subsequently followed by mrna degradation. however, one can not exclude that rnases might also regulate gene expression solely through their rna binding activity. notably, the dsrna binding activity of rnase iii has been reported to promote translation of lambda phage ciii rna. the first evidence of a modified degradosome came during a screen for suppressors of a cold - sensitive phenotype in a csda mutant. it was demonstrated that the rna helicase, csda, becomes incorporated in the rna degradosome complex in e. coli after cold shock and it can functionally replace rhlb, the typical rna helicase within the degradosome. it was proposed that the cold shock - induced csda associates with the degradosome to facilitate the unwinding of structured rnas at cold temperatures. furthermore, recent evidence revealed the association of the degradosome with components of central metabolism suggesting that these modified complexes may be part of a feedback network that allows the cell to coordinate rna decay with metabolic conditions. in caulobacter crescentus, the krebs cycle enzyme aconitase was found associated with the degradosome as opposed to the glycolytic enzyme enolase that is found in e. coli. binding of aconitase to the complex occurred through interaction with rnase e and levels of rnase e varied during the cell cycle. the connection between rna decay and central metabolism was further illustrated by the fact that citrate, a metabolite of the krebs cycle, has an inhibitory effect on the activity of pnpase in e. coli. it was recently pinpointed that an oxygen sensing system is able to adjust the level of c - di - gmp available to pnpase within a large ribonucleoprotein complex in e. coli and that this enhances pnpase activity. within this complex, pnpase, enolase, rnase e, rna terminator protein rho, several chaperone proteins (dnaj, dnak, groel), and oxygen - sensing proteins (dosc and dosp) were identified in addition to an rna moiety. altogether these different studies have identified variations to the degradosome complex that confer to the cell the capacity to sense and adapt to environmental changes. it is expected that future work characterizing modifications of the degradosome complex and their impact on rna decay will uncover connections between rna regulation and global metabolism. moreover, several examples have been highlighted where the activity of rnases can be cross - regulated. for instance, e. coli pnpase synthesis is autoregulated at the posttranscriptional level by an rnase iii - dependent mechanism. in fact, many of the rnases also appear to be regulated by a feedback mechanism and due to the fact that they are involved in rrna processing, their expression is thus coordinated with ribosome synthesis [156158 ]. as underscored above, the genomic context of the rnases might offer valuable cues towards understanding regulation of their expression. stage of growth and different stresses emerge as common themes in regulation of rnases activity [4, 78 ]. this paper highlights the importance of rnases in gene expression in several gram - positive pathogenic bacteria. furthermore, we have illustrated by several examples the roles of specific rnases in the regulation of the expression of mrna targets involved in virulence. however, the full repertoire of targets for rnases, and the roles of accessory proteins (rna helicases, rna - binding proteins) in gene regulation still need to be assessed, especially in gram - positive bacteria. without doubt our knowledge will greatly advance from current methodologies such as deep sequencing and tiling arrays where the full rnome of a bacterium can be evaluated in wild - type and mutant backgrounds. moreover, high - throughput sequencing combined with crosslinking immunoprecipitation (hits - clip) has proven valuable for identifying rna - protein interactions [160, 161 ]. this method could also lead to identification of the set of target rnas of an rnase. these new possibilities are expected to offer valuable insights into the function of these enzymes. the emergence of antibiotic resistances amongst pathogenic bacteria urgently necessitates the discovery of novel drugs. several possibilities of targeting components of the rna decay machinery in the design of novel drugs have been reported. recently, an inhibitory compound of rnpa was identified that proved to be effective against several strains of mrsa, biofilm associated s. aureus and against other gram - positive pathogens. despite the fact that the identified molecule exhibited cytotoxicity against a human cell line and can not be further exploited, it nevertheless sets the foundation for novel antimicrobial strategies targeting the rna degrading machinery. efforts have been focused on designing ligands nonmetabolizable by the cell that can specifically target riboswitches and repress growth [162, 163 ]. two modes of action have been envisioned for newly designed drugs aiming at activation of the toxin. the first approach involves turning down production of the antitoxin either at the transcriptional or the translational level whereas the second one aims at the disruption of the toxin - antitoxin interaction. in both cases, the result is degradation of the labile antitoxin and release of the toxin which ultimately results in self - inflicted cell death. the emergence of antibiotic resistances often relies on the presence of resistance genes residing on mobile genetic elements like plasmids which can be transferred to different species. since ta modules are responsible for stabilization of these elements, a strategy for targeting ta systems seems to hold promise for the design of novel antibiotics. a recent study by lasa. revealed an rna quality control function of s. aureus rnase iii. | it is widely acknowledged that rna stability plays critical roles in bacterial adaptation and survival in different environments like those encountered when bacteria infect a host. bacterial ribonucleases acting alone or in concert with regulatory rnas or rna binding proteins are the mediators of the regulatory outcome on rna stability. we will give a current update of what is known about ribonucleases in the model gram - positive organism bacillus subtilis and will describe their established roles in virulence in several gram - positive pathogenic bacteria that are imposing major health concerns worldwide. implications on bacterial evolution through stabilization / transfer of genetic material (phage or plasmid dna) as a result of ribonucleases ' functions will be covered. the role of ribonucleases in emergence of antibiotic resistance and new concepts in drug design will additionally be discussed. |
in china, maize (zea mays l.) is the most important cereal crop, and the production of this crop is affected by soil salinity. thus, many salinity - tolerant crops, such as maize and rice, have been developed using transgenic technology. researchers have found that the microbial communities in the rhizosphere are influenced by the plant. questions have been raised about whether antibiotic resistance genes, as selective markers, can transfer from genetically modified gm plants to indigenous microbes in the soil rhizospheres. another question is whether certain gm plants differentially affect soil microbial communities compared to non - gm plants [2, 3 ]. previous studies have shown that gm plants, including gm maize, potato, soybean, rice, and triticale, are equivalent to non - gm crops in terms of nutrition and are safe as food or feed. the effects of bacillus thuringiensis (bt) transgenic cotton (mech 162) and non - bt plants of the same cultivar on the ecology of many organisms in the soil were evaluated over three years in a subtropical environment. the authors concluded that the bt cotton mech 162 did not have any negative effects on the organisms or biochemical characteristics of the soil. the bacterial communities in the rhizosphere were studied using gm and non - gm maize in another study. plant growth can promote rhizobacterial multiplication associated with both gm and non - gm plants, which indicates the mutually beneficial relationship between rhizobacteria and maize. no significant differences in the isolated rhizospheres were found during plant growth in gm or non - gm plants. using transgenic, salinity - tolerant suv3 and pdh45 rice, the communication between rhizobacteria and rice was studied, and no significant effect was found [3, 7 ]. however, there have been few reports of the influence of gm and non - gm maize on rhizosphere soils. the bcwrky1 gene was cloned from boea crassifolia hemsl, and it encodes a 444-amino acid wrky - like protein containing two conserved domains : wrkygqk and c2h2 motifs. the full - length bcwrky1 cdna was 1,803 bp, and its expression could be induced by abiotic stresses, including soil salinity, low temperature, and drought. in addition, bcwrky1 transcription was accompanied by changes in plant hormones, including abscisic acid (aba), salicylic acid (sa), and jasmonic acid (ja). then, the boea crassifolia dna helicase of bcwrky1 was overexpressed under salt stress in maize. the nacl stress - tolerant phenotype appeared even when plants were irrigated continuously with 150200 mm nacl, with no effect on their yield. furthermore, other salt - induced genes, including gmwrky54, tawrky2, and hvwrky38, in arabidopsis thaliana also promoted strong nacl stress - tolerant phenotypes [1012 ]. in this study, gm maize (wl-73) plants overexpressing the bcwrky1 gene and control non - gm maize lh1037 were used to evaluate the effects of wl-73 growth on the microbial populations in saline or nonsaline soils in harbin, china. bcwrky1-transgenic maize, which carries a kanamycin resistance gene, was compared to non - gm lh1037 maize to determine its effects on rhizosphere soil in terms of enzyme activities (including dehydrogenase, alkaline phosphatase, urease, and sucrase activities), physicochemical properties, and microbial populations. the line wl-73 was derived from the maize inbred line lh1037 transformed with the vector pcambia 3300-ubi - wrky1 (figure 1). seeds were obtained from t0 antisaline transgenic maize selected by saline stress and self - crossed to t6 ; wl-73 plants overexpressing bcwrky1 were able to survive under 300 mm nacl stress. the seeds of wl-73 and its receptor line lh1037 (wt) were grown in a three - row field with simulated saline - alkaline soil derived from a natural saline - alkaline field in heilongjiang province, china. the saline soil contained 29.42 gkg organic matter, 0.31 gkg total n, 127.27 mgkg available n (an), 23.54 mgkg available p (ap), and 178.91 mgkg available k (k2o) (ak) and had a ph of 8.65. the nonsaline control soil contained 58.02 gkg organic matter, 0.31 gkg total n, 119.26 mgkg an, 26.01 mgkg ap, and 267.14 mgkg ak and had a ph of 7.67. the seeds were salt and mock treated following di 's method with modifications. wt and wl-73 seeds were germinated in sterilized vermiculite in a greenhouse with a humidity of 4050% at 22c and a light cycle of 16 h light/8 h darkness. in addition, 0.5x hoagland 's nutrient solution with 300 mmol nacl was applied to the salt treatment plants daily for 7 days, while the same solution without nacl was applied to the control plants at the same frequency. both the salt - treated and control plants in the experiment were then watered with 0.5x hoagland 's nutrient solution every 3 days to prevent excessive nacl accumulation in the vermiculite. leaves of the salt - treated seedlings were collected, and dna and rna were isolated. the ctab method was used to isolate genomic dna from the two youngest leaves of each plant. total rna was isolated using trizol following the manufacturer 's protocol (tiangen biotech, beijing, china) under the requirement of 100 mg of young seeding leaves per ml of trizol. in addition, the membrane integrity parameters of the plants were determined by detecting superoxide dismutase (sod) and peroxidase (pod) activity, proline (pro) and malondialdehyde (mda) content, relative electrical conductivity (rec), and chlorophyll content in leaves following the methods of arnon and bates.. wl-73 and wt maize plants were grown in saline or conventional soil in triplicate from 2012 to 2014 at the transgenic experiment station of northeast agricultural university, harbin, heilongjiang, china (longitude 12673, latitude 4575). soil samples were isolated from the rhizosphere of wl-73 and wt at the v3 (the three lowest leaves have a visible collar), v9 (nine leaves have collars present), r1 (silking), and r6 (physiological maturity) stages. after removing the surface leaves, three soil samples from each plot the soil volumes between 0 and 20 cm in depth were extracted using a soil auger with a 4 cm diameter, and the bulk soil on the root was shaken off. the soil from the root was stripped using a sterilizing brush and constituted the rhizosphere soil samples. we mixed three rhizosphere soil samples from each plot into one sample and then divided this sample into two. another sample was air - dried at room temperature, homogenized by sieving through a 2 mm mesh, and stored at 4c until analysis. soil sucrase activity was measured using the 3,5-dinitrosalicylic acid method [21, 22 ]. the physicochemical characteristics of soil and nutrient constituents, including soil type, ph, electrical conductivity (ec) (mscm), organic carbon (oc) (%), an (kgha), ap (kgha), and ak (kgha), were determined. a 50 g soil sample was suspended in 100 ml of distilled, deionized water and stirred for 1 h at 100 rpm on a rotary shaker. the ec was recorded using a conductivity meter against 0.01 n kcl, and the ph was measured. the available carbon, nitrogen, phosphorus, and potassium contents in the soils were determined following standard methods [2427 ]. the calcium (ca), sodium (na), and magnesium (mg) ion concentrations were determined using an atomic absorption method to determine the sodium adsorption ratio (sar). the sar was then calculated using the following formula : (1)sar = na+1/2ca2++mg2 +. to obtain isolated colonies, serial dilutions (10 dilution) prepared from 1 g soil samples colonies were then selected, diluted, and spread onto plates containing beef extract peptone agar to detect bacteria, gause 's agar to detect actinomycetes, and rose bengal agar to detect fungi. three replicates of the inoculated agar plates were incubated at 30c, 28c, or 28c for 3 d for bacteria, 3 d for actinomycetes, and 5 d for fungi, after which the number of various types of colonies was recorded. the total populations of bacteria, actinomycetes, and fungi in each petri dish were counted as colony forming units (cfu)g dry soil. the block treatments were the four growth stages (v3, v9, r1, and r6), the two maize materials (wl-73 and wt), and the two soil types (saline and nonsaline). all of the experiments were performed with three biological replicates over three years from 2012 to 2014. an analysis of variance (anova) was performed on treatment means using a generalized linear mixed model (glmm), including treatment and sample time, in sas 9.1 (copyright 2008, sas institute, cary, nc). the bcwrky1 gene was cloned from boea crassifolia, which has the ability to tolerate salt stress. wl-73 transgenic plants overexpressing the bcwrky1 gene were successfully generated by agrobacterium - mediated transformation with the binary vector pcambia3300-ubi - bcwrky1 (figure 1) introduced into the inbred line lh1037. the 1308-bp bcwrky1 pcr product was amplified from wl-73 transgenic plants with bcwrky1 gene - specific primers (figure 2(a)). the transcription of the bcwrky1 gene in plant leaves was detected by rt - pcr (table 1, figure 2(b)). as expected, pcr and rt - pcr bands characteristic of bcwrky1 were detected in wl-73 but not in wt plants. when we treated maize plants with 300 mm nacl solution for 7 days, the wl-73 plants were 5.3 cm taller and 60% heavier (fresh weight) than wt plants (table 2). wt seedlings became almost entirely yellow on the 7th day after salt stress (figure 3). the membrane integrity of the plants was measured in terms of parameters such as sod, pod, pro, mda content, rec, and chlorophyll content following salt stress (figure 4). the sod, pod, pro, mda, and rec of wl-73 plants were significantly lower than those of wt plants (p 0.05) in the two soil environments (saline or nonsaline) or at any of the four growth stages (v3, v9, r1, and r6). the anova results showed that the dehydrogenase and alkaline phosphatase activities in the rhizosphere soil of wl-73 and wt maize were similar, with values ranging from 34.84 to 39.04 g pnp gh in saline soil and from 40.74 to 57.44 g pnp gh in control soil for wl-73 and from 34.74 to 41.85 g pnp gh in saline soil and from 40.62 to 59.26 g pnp gh in control soil for wt maize (tables 3 and 4 ; figures 5(a)5(d)). however, the activities of these four soil enzymes were significantly different between wl-73 and wt plants in some soil environments, years, and growth stages. for example, there were significant differences in alkaline phosphatase activity in saline soil at r6 in 2013 (p = 0.03) ; in urease activity in control soil at r1 in 2012 and in saline soil at v9 in 2013 (p 0.05) at four maize growth periods (r1, r9, v1, and v6) in saline and control soil environments from 2012 to 2014 (table 5). however, there were significant differences between wl-73 and wt plants (p 0.05). however, we did not find a significant effect on enzyme activities, physicochemical properties, or populations of soil microbes due to the long - term cultivation of wl-73 compared to wt. our results are consistent with previous studies showing that the long - term cultivation of salt - tolerant gm plants has no effect on soil microbial populations. the effects that we observed were due to particular individual plants, techniques, exogenously expressed proteins, or environmental conditions. in the present study, the minor significant differences in the rhizosphere soil between transgenic and nontransgenic maize plants were not as large as the effects associated with plant growth stages. these results indicated that the effects of bcwrky1 maize wl-73 on rhizosphere soil ecology are within the variation expected in conventional agriculture. the long - term planting (3 years) of wl-73 plants had no detectable effects on the enzymatic activities, physicochemical properties, or microbial populations of the rhizosphere soil compared with the wt at any of four maize growth stages (v3, v9, r1, and r6). | maize (zea mays l.) is the most important cereal crop in the world. however, soil salinity has become a major problem affecting plant productivity due to arable field degradation. thus, transgenic maize transformed with a salinity tolerance gene has been developed to further evaluate its salt tolerance and effects on agronomic traits. it is necessary to analyze the potential environmental risk of transgenic maize before further commercialization. enzyme activities, physicochemical properties, and microbial populations were evaluated in saline and nonsaline rhizosphere soils from a transgenic maize line (wl-73) overexpressing bcwrky1 and from wild - type (wt) maize lh1037. measurements were taken at four growth stages (v3, v9, r1, and r6) and repeated in three consecutive years (20122014). there was no change in the rhizosphere soils of either wl-73 or wt plants in the four soil enzyme activities, seven soil physicochemical properties, and the populations of three soil organisms. the results of this study suggested that salinity tolerant transgenic maize had no adverse impact on soil properties in soil rhizosphere during three consecutive years at two different locations and provided a theoretical basis for environmental impact monitoring of salinity tolerant transgenic maize. |
a 28-year - old male patient came to our hospital outpatient department with complaints of short hair (5 - 8 mm in length) coming out from the left upper eyelid since childhood as reported by his parents. on close examination by the dermatologist and the physician, the ectopia cilia was located 7 mm superior - lateral to the left upper lid margin. the patient 's maternal grandfather (since deceased) had similar ectopia cilia on left upper eyelid as was reported by patient 's mother [figure 2 ]. ectopia cilia with eleven hair lash bundles pedigree chart of ectopia cilia an out - patient surgical excision procedure under local anesthesia was done. an incision parallel to the lid margin was given and root of the tuft dissected. histological findings were suggestive of eccrine sweat glands with no features of apocrine glands and dermoid cyst seen as reported by the pathologist. after 3 month 's follow - up, no recurrence was detected. the presentations in published works falls in two distinct categories : cilia protruding from the anterior surface and cilia protruding from posterior surface of the tarsal plate. the anteriorly placed cilia are uniformly located on the lateral quarter of the upper eyelid and associated with the presence of apocrine sweat glands and are congenital in origin. dalgleish presented two cases - one of them had large apocrine sweat glands attached to the follicle. baghestani and banihashemi reported first case of ectopia cilia with pedigree analysis in a 14-year - old iranian boy with a positive history of the same anomaly in his paternal grandfather demonstrating evidence of an inherited genetic disorder. reported that only nine cases of ectopia cilia have been reported so far till 1991. the differential diagnosis of ectopia cilia includes several eyelash abnormalities such as cilia incarnata, a condition in which an extra eyelash grows from a normal origin through the eyelid to the inner aspect of the tarsal conjunctiva or outward to the skin. wang. presented an unusual case of a dermoid cyst presenting with black hairs emerging from a sinus tract on the upper eyelid and mimicking the appearance of ectopic cilia. distichiasis and trichiasis are other conditions which also need to be differentiated from ectopia cilia. trichiasis is a condition in which cilia originates from a normal position on the eyelid turn inward due to entropion. the nearness of tuft to the tarsal plate, the texture and the direction of the cilia suggest that the origin of the ectopia cilia may probably be related to the eyelashes in our patient. | we present a case of ectopia cilia in a 28-year - old male patient. ectopia cilia was were seen in the outer third of left upper eyelid. the patient 's maternal grandfather also had ectopia cilia of the left upper eyelid as reported by the patient 's mother. ectopia cilia is a rare condition seen in humans. only 12 cases of ectopic cilia in humans have been reported so far in the world. the present case of ectopia cilia is the second case report in the world with pedigree analysis. |
the different forms of acute myeloid leukemias (amls) are characterized by the arrest of cell differentiation, the induction of cell proliferation, and the repression of normal hematopoiesis. these malignancies are often associated with recurrent chromosomal translocations, most of which encode fusion proteins derived from transcription factors (1). functional analyses of several of these fusion proteins have shown that they behave like potent transcriptional repressors (2). repression is often achieved through the modification of chromatin structure by histone desacetylases which blocks the expression of unidentified genes that control myeloid differentiation. the inhibition of desacetylases by a variety of compounds has been fairly effective in cell culture (3) and in animal models of leukemia (4), but as yet, there only is slight evidence of its beneficial effects in clinical settings (5). to date, the only real clinical success of transcription / differentiation therapy has been in acute promyelocytic leukemia (apl), for which two drugs, retinoic acid (ra) and arsenic trioxide (as2o3) induce remissions (6, 7). the action of these drugs is remarkable because they both target the oncogenic promyelocytic leukemia (pml)retinoic acid receptor (rara) fusion protein and reverse pml / rara mediated repression (8). cyclic adenosine monophosphate (camp) also differentiates many aml cell line and strongly synergizes with other differentiating agents (references 9 and 10 ; for a review, see reference 11). moreover, in apl cells, camp can decrease the concentrations of ra required for differentiation to almost physiological ones (12). however, a number of acute toxic reactions have precluded or severely limited trials using camp derivatives (13). here, we used an animal model of apl derived from pml / rara transgenic mice (14) to study the effects of camp in vivo. we showed that camp induces major cell growth arrest together with differentiation and synergizes with both as2o3 and ra to clear ra - sensitive or ra - resistant apl. in an apl patient who had become resistant to ra and as2o3 therapy, addition of theophylline, an inhibitor of camp intracellular degradation, induced a clinical remission. that activation of camp signaling is beneficial in apl, independently of its sensitivity to ra, raises hopes for the successful treatment of therapy - resistant forms of aml. morphology and differentiation of the apl cell line nb4 were evaluated on may - grnwald giemsa 8-chloro - adenosine 3 - 5 cyclic monophosphate (8-cl - camp) and 8-(4-chlorophenylthio)adenosine 3 - 5 cyclic monophosphate (8-cpt - camp ; reference 15) were respectively obtained from the biology life research institute and sigma - aldrich. 8-cpt - camp was used at a concentration of 2.10 m. spleen - derived leukemic blasts (10) were serially passaged in syngeneic fvb / n mice 6 wk old, weighing 20 g, as described previously (14). both ra - sensitive leukemias (strain 935) or ra - resistant leukemias (strain 4048 ; reference 16) were used. all experiments involving mice were repeated between two and eight times, usually with two mice in each treatment arm. 0.5 l / h alzet pumps were loaded with 20 mg / ml 8-cl - camp and implanted subcutaneously on the back of treated mice. aminophylline, a stabilized precursor of theophylline, was injected intraperitoneally (100 l / day of a 25 mg / ml solution). ra and as2o3 treatments, autopsies, and cell or tissue analyses were performed as described previously (14). for western blot analysis, plasma 8-cl - camp was measured by hplc using a c18 column (chromosep inertil 5 ods3) with a 15% methanol/50 mm phosphate buffer, ph 5.85, as a mobile phase and uv detection at 254 nm. the patient studied gave informed consent to the use of theophylline to enhance ra / as2o3 differentiation. the patient 's daily treatment consisted of 45 mg / m ra per os, 10 mg as2o3 intravenously, and 250 mg theophylline per os. it is well known that camp greatly enhances the ra - induced differentiation of many cell lines derived from embryonal carcinoma or myeloid leukemias, including apl (10). as low concentrations of as2o3 were found to induce only incomplete differentiation in an apl cell line (7), we tested the hypothesis that camp would also enhance as2o3-induced differentiation. even very low doses of as2o3 combined with 8-cpt - camp (a low toxicity camp analog) induced nbt reduction in 40% of the nb4 cells, whereas camp or as2o3 alone did not have significant effects (unpublished data, see fig. similarly, only combined as2o3 and 8-cpt - camp induced morphologic differentiation of nb4 cells into myelocyte - like cells (unpublished data), as reported recently (17). to assess the possible in vivo efficiency of camp, we used transplantation apl model (14) derived from ra - sensitive pml / rara transgenic mice (18). we developed a similar transplantation model for ra - resistant apl, using leukemic cells from pml / rara transgenic mice in which a point mutation in the transgene impairs the binding of ra to pml / rara (16). in vivo growth of this leukemia is much slower than in the ra - sensitive model, liver, or spleen invasion is not as pronounced and either ra or as2o3 have mild antiproliferative effects in the absence of significant differentiation (see fig. mice bearing established leukemias were treated with 8-cl - camp, as2o3, ra, or combinations of these drugs and killed 17 d after treatment. continuous 8-cl - camp infusions allowed significant plasma concentrations to be reached (1 m on an average at day 3). despite its toxicity, 8-cl - camp induced major antileukemic effects in both ra - sensitive and ra - resistant apls, as assessed by spleen weight (fig. myeloid cells undergoing differentiation were always observed in the marrow of ra - resistant apl after 7 d of treatment, and were often found upon treatment of ra - sensitive apl (fig. 1). in leukemic cells infiltrating the liver, a sharp reduction in the number of mitoses was observed after 8-cl - camp treatment (3% post- versus 28% pretreatment) and a few condensed nuclei were seen (unpublished data). these results show that in these ra - sensitive or ra - resistant mouse models of apl, camp triggers a combination of cell growth arrest, differentiation, and apoptosis, leading to dramatic regressions of the leukemia. 8-cl - camp induces growth arrest in ra - sensitive (ra, a) or ra - resistant (ra, b) apl in mice. (top) spleen weight after 7 d of 8-cl - camp treatment or no therapy (). (bottom) liver from the same mice. since camp greatly increased as2o3-triggered differentiation ex vivo in the nb4 cell line (fig. 2 a), we combined 8-cl - camp and as2o3 treatments in vivo. with this combination, the spleen, liver, and bone marrow of mice with ra - sensitive apl became free of leukemia between days 1 and 3, whereas mice treated with as2o3 or camp alone retained a significant tumor burden consisting of differentiating leukemic cells (fig. 2, b, e, and f). note that erythroblasts and megakaryocytes were extremely numerous in a cell - rich marrow (fig. 2 e), in agreement with the idea that camp promotes the regrowth of these cells. in keeping with our ex vivo results, camp synergized with as2o3 to trigger differentiation, as shown by cd11b expression on bone marrow blasts at day 1 (fig. 2 c), strongly suggesting that enhanced differentiation of the leukemic blasts contributes to these accelerated remissions. the level of the cdk inhibitor p21, a known camp target implicated in growth arrest, differentiation, and apoptosis, rose strikingly in bone marrow apl blasts upon treatment in vivo (fig. synergy was also noted between 8-cl - camp and ra with respect to both spleen weight and marrow cell differentiation, although this synergy was dimmed by the stronger differentiating effect of ra (fig. 3). arsenic and camp synergize to induce tumor regression and differentiation in ra - sensitive apl. (a) 8-cpt - camp potentiates as2o3-induced nbt reduction at 4 d in the apl cell line nb4. (b) in a mouse model of apl, continuous infusion of 8-cl - camp for 3 d greatly reduces spleen weight and synergizes with as2o3 (as) to induce tumor reduction (one representative experiment). (c) cd11b expression on bone marrow cells after 24 h of in vivo treatments, as indicated. (d) 8-cl - camp induces p21 expression in leukemic bone marrow after 24 h of in vivo treatment. cross - reactive protein. 3 d of combined treatment restores normal hematopoiesis in the bone marrow (e) and induces tumor clearance from the liver (f). (g) theophylline (t) therapy (3 d) induces blast differentiation. (a) spleen weight after 7 d of treatment or untreated (). 8-cl - camp induced even more dramatic regressions in ra - resistant apl, with some morphologically complete clearances (figs. 1 and 4). unexpectedly, major enhancements of leukemia clearance and differentiation were always observed when ra was combined with 8-cl - camp (fig. although as2o3 alone triggered a slight antiproliferative effect in the absence of significant differentiation, the ra / as2o3 combination triggered minor, but reproducible, differentiation (fig. 4 b). the stable camp derivative used here induces massive diuresis, precluding any long - term use, and may be further metabolized into potentially cytotoxic nucleotide analogs (15). to ensure that the antileukemic effect indeed resulted from the activation of camp signaling, we used theophylline, a phosphodiesterase inhibitor which stabilized pools of endogenous intracellular camp. like 8-cl - camp, the - ophylline blocked growth in ra - sensitive apl and induced some apoptosis, accompanied by non - terminal differentiation (fig. as expected, the enhancement of differentiation was more pronounced with as2o3 than with ra (fig. however, there was no obvious boost in normal hematopoiesis, possibly reflecting low production of endogenous camp in normal cells. on the basis of these promising results in mouse apl, an ra / as2o3-resistant apl patient was offered an experimental course of combined ra / as2o3/theophylline therapy. previously, a month of the ra / as2o3 combination had led to a slow decrease in bone marrow blasts, a peak of differentiating myeloid cells in the blood (fig. 5), but normal hematopoiesis was not restored and the leukemia had reappeared 5 wk later (fig. 5, a and b). however, with combined ra / as2o3/theophylline treatment, leukemic cells underwent differentiation and normal erythroblasts appeared rapidly (fig. 5, a and c). the patient no longer required red cell or platelet transfusions and white blood cells and hemoglobin reached levels close to the normal ones. the patient remained leukemia free for 4 mo, but then the leukemic clone reappeared. paradoxically, with ongoing ra / as2o3/theophylline therapy and despite the leukemia relapse, normal hematopoiesis has been maintained to date (5 mo since relapse), an extremely unusual situation in apl, in which cytopenia is the first sign of relapse. theophylline synergizes with ra / as2o3 therapy in a multirelapsed patient with ra / as2o3-resistant apl. (a) schematic representation of clinical events. (b and c) representative images of bone marrow samples taken at days 0, 14, and 28 of the initial ra / as2o3 course (b) or the following ra / as2o3/theophylline course (c). note the rapid differentiation in (c) with the reappearance of normal erythroblasts at day 14, as well as the maintenance of normal hematopoiesis despite leukemia relapse. it is well known that camp greatly enhances the ra - induced differentiation of many cell lines derived from embryonal carcinoma or myeloid leukemias, including apl (10). as low concentrations of as2o3 were found to induce only incomplete differentiation in an apl cell line (7), we tested the hypothesis that camp would also enhance as2o3-induced differentiation. even very low doses of as2o3 combined with 8-cpt - camp (a low toxicity camp analog) induced nbt reduction in 40% of the nb4 cells, whereas camp or as2o3 alone did not have significant effects (unpublished data, see fig. similarly, only combined as2o3 and 8-cpt - camp induced morphologic differentiation of nb4 cells into myelocyte - like cells (unpublished data), as reported recently (17). to assess the possible in vivo efficiency of camp, we used transplantation apl model (14) derived from ra - sensitive pml / rara transgenic mice (18). we developed a similar transplantation model for ra - resistant apl, using leukemic cells from pml / rara transgenic mice in which a point mutation in the transgene impairs the binding of ra to pml / rara (16). in vivo growth of this leukemia is much slower than in the ra - sensitive model, liver, or spleen invasion is not as pronounced and either ra or as2o3 have mild antiproliferative effects in the absence of significant differentiation (see fig. mice bearing established leukemias were treated with 8-cl - camp, as2o3, ra, or combinations of these drugs and killed 17 d after treatment. continuous 8-cl - camp infusions allowed significant plasma concentrations to be reached (1 m on an average at day 3). despite its toxicity, 8-cl - camp induced major antileukemic effects in both ra - sensitive and ra - resistant apls, as assessed by spleen weight (fig. myeloid cells undergoing differentiation were always observed in the marrow of ra - resistant apl after 7 d of treatment, and were often found upon treatment of ra - sensitive apl (fig. 1). in leukemic cells infiltrating the liver, a sharp reduction in the number of mitoses was observed after 8-cl - camp treatment (3% post- versus 28% pretreatment) and a few condensed nuclei were seen (unpublished data). these results show that in these ra - sensitive or ra - resistant mouse models of apl, camp triggers a combination of cell growth arrest, differentiation, and apoptosis, leading to dramatic regressions of the leukemia. 8-cl - camp induces growth arrest in ra - sensitive (ra, a) or ra - resistant (ra, b) apl in mice. (top) spleen weight after 7 d of 8-cl - camp treatment or no therapy (). (bottom) liver from the same mice. since camp greatly increased as2o3-triggered differentiation ex vivo in the nb4 cell line (fig. 2 a), we combined 8-cl - camp and as2o3 treatments in vivo. with this combination, the spleen, liver, and bone marrow of mice with ra - sensitive apl became free of leukemia between days 1 and 3, whereas mice treated with as2o3 or camp alone retained a significant tumor burden consisting of differentiating leukemic cells (fig. note that erythroblasts and megakaryocytes were extremely numerous in a cell - rich marrow (fig. 2 e), in agreement with the idea that camp promotes the regrowth of these cells. in keeping with our ex vivo results, camp synergized with as2o3 to trigger differentiation, as shown by cd11b expression on bone marrow blasts at day 1 (fig. 2 c), strongly suggesting that enhanced differentiation of the leukemic blasts contributes to these accelerated remissions. the level of the cdk inhibitor p21, a known camp target implicated in growth arrest, differentiation, and apoptosis, rose strikingly in bone marrow apl blasts upon treatment in vivo (fig. synergy was also noted between 8-cl - camp and ra with respect to both spleen weight and marrow cell differentiation, although this synergy was dimmed by the stronger differentiating effect of ra (fig. 3). arsenic and camp synergize to induce tumor regression and differentiation in ra - sensitive apl. (a) 8-cpt - camp potentiates as2o3-induced nbt reduction at 4 d in the apl cell line nb4. (b) in a mouse model of apl, continuous infusion of 8-cl - camp for 3 d greatly reduces spleen weight and synergizes with as2o3 (as) to induce tumor reduction (one representative experiment). (c) cd11b expression on bone marrow cells after 24 h of in vivo treatments, as indicated. (d) 8-cl - camp induces p21 expression in leukemic bone marrow after 24 h of in vivo treatment. 3 d of combined treatment restores normal hematopoiesis in the bone marrow (e) and induces tumor clearance from the liver (f). (g) theophylline (t) therapy (3 d) induces blast differentiation. (a) spleen weight after 7 d of treatment or untreated (). 8-cl - camp induced even more dramatic regressions in ra - resistant apl, with some morphologically complete clearances (figs. 1 and 4). unexpectedly, major enhancements of leukemia clearance and differentiation were always observed when ra was combined with 8-cl - camp (fig. although as2o3 alone triggered a slight antiproliferative effect in the absence of significant differentiation, the ra / as2o3 combination triggered minor, but reproducible, differentiation (fig. the stable camp derivative used here induces massive diuresis, precluding any long - term use, and may be further metabolized into potentially cytotoxic nucleotide analogs (15). to ensure that the antileukemic effect indeed resulted from the activation of camp signaling, we used theophylline, a phosphodiesterase inhibitor which stabilized pools of endogenous intracellular camp. like 8-cl - camp, the - ophylline blocked growth in ra - sensitive apl and induced some apoptosis, accompanied by non - terminal differentiation (fig. as expected, the enhancement of differentiation was more pronounced with as2o3 than with ra (fig. however, there was no obvious boost in normal hematopoiesis, possibly reflecting low production of endogenous camp in normal cells. on the basis of these promising results in mouse apl, an ra / as2o3-resistant apl patient was offered an experimental course of combined ra / as2o3/theophylline therapy. previously, a month of the ra / as2o3 combination had led to a slow decrease in bone marrow blasts, a peak of differentiating myeloid cells in the blood (fig. 5), but normal hematopoiesis was not restored and the leukemia had reappeared 5 wk later (fig. 5, a and b). however, with combined ra / as2o3/theophylline treatment, leukemic cells underwent differentiation and normal erythroblasts appeared rapidly (fig. 5, a and c). the patient no longer required red cell or platelet transfusions and white blood cells and hemoglobin reached levels close to the normal ones. the patient remained leukemia free for 4 mo, but then the leukemic clone reappeared. paradoxically, with ongoing ra / as2o3/theophylline therapy and despite the leukemia relapse, normal hematopoiesis has been maintained to date (5 mo since relapse), an extremely unusual situation in apl, in which cytopenia is the first sign of relapse. theophylline synergizes with ra / as2o3 therapy in a multirelapsed patient with ra / as2o3-resistant apl. (a) schematic representation of clinical events. (b and c) representative images of bone marrow samples taken at days 0, 14, and 28 of the initial ra / as2o3 course (b) or the following ra / as2o3/theophylline course (c). note the rapid differentiation in (c) with the reappearance of normal erythroblasts at day 14, as well as the maintenance of normal hematopoiesis despite leukemia relapse. our data demonstrate that in vivo activation of camp signaling was beneficial in two distinct mouse models of apl, as well as in an ra / as2o3-resistant apl patient. the relative balance between growth arrest, apoptosis, and differentiation presumably depends on the dose of 8-cl - camp, the microenvironment of the apl blasts (marrow versus liver metastasis, for example) and their nature (ra - sensitive or ra - resistant cells). camp - triggered growth arrest may result from induction of the cdk inhibitor p21, which was previously found to be involved in ra - induced apl cell differentiation (19). enhancement of ra-, as2o3-, or rexinoid - triggered differentiation by camp may also result from induction of g - csf expression (20). in f9 embryonal carcinoma cells, camp was shown to modulate ra - triggered differentiation directly through rara phosphorylation (21). since rara plays a critical role in myeloid differentiation, including in its regulation by il-3 and gm - csf (22), the camp triggered myeloid differentiation may similarly be caused by modulation of rara signaling. at present, we can not explain the greater sensitivity to 8-cl - camp of ra - resistant apl cells, but it might be due to their slower growth rate. in european trials, therapy - resistant patients only exceptionally exhibit mutations in pml / rara, which does not favor a direct parallel between the case of this patient and ra - resistant apl mice. indeed, a cell line (nb4-lr2) that harbors a mutation in pml / rara very similar to the one present in the ra - resistant apl cells used here, failed to differentiate upon combined ra/8-cl - camp treatment, but only matured upon combined camp / rexinoid exposure (20). therefore, our observations might reflect an in vivo metabolism of ra to rexinoids and activation of this parallel pathway. absence of major synergy between camp and as2o3 in ra - resistant apl, compared to ra - sensitive disease, may reflect the low potency of as2o3 and the striking efficacy of 8-cl - camp in this setting. as2o3 was initially believed to trigger apoptosis, but recent observations have suggested that differentiation was the dominant mechanism (for a review, see reference 23). the dramatic enhancement of as2o3-triggered differentiation by 8-cl - camp both ex vivo and in vivo (fig. 2 and reference 17), greatly strengthens this idea. in the patient, as in the apl mice, camp induced rapid regrowth of normal erythroblasts and megakaryocytes. this might have resulted from a direct positive effect on the normal progenitors, as reported ex vivo (24). alternatively, apl cells might secrete inhibitors of normal hematopoiesis (25, 26) whose synthesis or downstream signaling, may be blocked by camp. in the clinical setting, such an in vivo stimulatory effect on normal hematopoiesis could be as important as leukemia inhibition. the low toxicity of theophylline, its ability to accelerate ra- or as2o3triggered remissions and the observation that the rapid induction of ex vivo differentiation is predictive of outcome in apl (27), could favor the use of theophylline for de novo apl patients. in addition, unlike ra and as2o3, camp does not obviously target pml / rara and might therefore be beneficial in malignancies other that apl. indeed, patients with chronic lymphocytic leukemia experienced faster clinical remissions when theophylline was combined with low - dose chemotherapy (28). similarly, a patient on viagra, another phosphodiesterase inhibitor, exhibited regression of b cell chronic lymphocytic leukemia (29). many aml - derived cell lines are very sensitive to camp - triggered differentiation, particularly in the presence of other differentiation inducers. like histone desacetylase inhibitors, which unravel ra - induced differentiation (3, 30), the - ophylline | differentiation therapy for acute myeloid leukemia uses transcriptional modulators to reprogram cancer cells. the most relevant clinical example is acute promyelocytic leukemia (apl), which responds dramatically to either retinoic acid (ra) or arsenic trioxide (as2o3). in many myeloid leukemia cell lines, cyclic adenosine monophosphate (camp) triggers growth arrest, cell death, or differentiation, often in synergy with ra. nevertheless, the toxicity of camp derivatives and lack of suitable models has hampered trials designed to assess the in vivo relevance of theses observations. we show that, in an apl cell line, camp analogs blocked cell growth and unraveled as2o3-triggered differentiation. similarly, in ra - sensitive or ra - resistant mouse models of apl, continuous infusions of 8-chloro - cyclic adenosine monophosphate (8-cl - camp) triggered major growth arrest, greatly enhanced both spontaneous and ra- or as2o3-induced differentiation and accelerated the restoration of normal hematopoiesis. theophylline, a well - tolerated phosphodiesterase inhibitor which stabilizes endogenous camp, also impaired apl growth and enhanced spontaneous or as2o3-triggered cell differentiation in vivo. accordingly, in an apl patient resistant to combined ra as2o3 therapy, theophylline induced blast clearance and restored normal hematopoiesis. taken together, these results demonstrate that in vivo activation of camp signaling contributes to apl clearance, independently of its ra - sensitivity, thus raising hopes that other myeloid leukemias may benefit from this therapeutic approach. |
transrectal ultrasound guided prostate biopsy (trus - bx) is a standard procedure used for prostate cancer detection. however, it has recently been reported that most of the patients that undergo trus - bx tolerated the associated discomfort, and 20% of these patients experienced severe pain [1 - 3 ]. therefore, researchers have tried to reduce the pain associated with the trus - bx. if the procedure - associated pain could be reduced, this may improve patient compliance. the two main causes of the pain during the biopsy are the transducer inserted into the rectum, and the biopsy needle that advances through the prostate capsule. to decrease the associated pain, several anesthetic methods including analgesics, topical applications, and nerve blocks have been used. among these methods, however, this does not control the pain associated with the transducer being inserted into the anus. therefore, in an effort to decrease the pain from the insertion, several studies have shown the efficacy of applying lidocaine - prilocaine cream or lidocaine jelly along with ppnb. however, no prior study on the application of lidocaine - prilocaine cream with ppnb has been carried out in korea. therefore, the effects on pain control of perianal - intrarectal lidocaine - prilocaine (pilp) cream applied to the anus and rectum in addition to ppnb were evaluated in this study. from october 2007 to august 2009, a prospective, randomized, placebo - controlled study was performed. patients that satisfied the inclusion criteria were enrolled including patients with any of the following : 1) increased prostate - specific antigen (psa) with or without an abnormal digital rectal examination (dre) ; 2) lesions suspicious for a malignancy on the trus with or without an abnormal dre ; or 3) an abnormal dre finding. patients were excluded if they had a history of a previous prostate biopsy, had chronic prostatalgia, anal diseases such as an anal fissure, hemorrhoids, anal surgery, chronic prostatitis / pelvic pain syndrome, concomitant analgesic medication, any other medical condition that could potentially interfere with pain assessment, a history of warfarin treatment or a bleeding tendency, or impaired intellectual ability. a total of 74 men who met the criteria and agreed to participate in the study were enrolled after providing written consent. they were then randomized by a coin toss to undergo trus - bx with combined anesthesia (pilp cream and ppnb) (group 1), or ppnb only (lubricant jelly and ppnb) (group 2). a urologist administered the pilp cream (5 ml, 5 g) or inert lubricant gel intrarectally with a syringe and massaged it into the anterior rectal wall anal canal and perianal skin. patients were informed that they had received a dose of a topical substance but they were blinded to the randomization results. thirty minutes after the application the prostate trus - bx was performed. for the nerve block technique, the patients received 10 cc of 1% lidocaine local injections into both sides of the prostate 's lateral posterior area guided by a transrectal ultrasound. a philips iu-22 transducer (philips, bothell, wa, usa) with a 9.5 mhz rectal probe was used for images in the transaxial and sagittal planes. in most patients, 12 core prostate biopsies were performed, including six parasagittal and six laterally targeted biopsies covering the base, mid zones, and apexes, using a spring - loaded biopsy gun and an 18 gauge acecut biopsy needle (tsk laboratory, tochigi, japan). three hours after the biopsy, another urologist who had no information about the two groups asked the patients about the pain during the trus - bx. the scale was a linear, 10-point visual analog scale of 0 to 10 cm with pain / discomfort, scored as 0 : no pain, 1 to 3 : mild, 4 to 6 : moderate, 7 to 9 : severe and 10 : unbearable pain. all patients were discharged the next day after observation for complications such as gross hematuria, rectal bleeding, voiding difficulty, or fever. a week after discharge, the patients were assessed for the results of the biopsy and other possible side effects. differences in the age, psa levels, volume of the prostate, vas scores, and complications were compared between the two treatment and control groups. the difference in pain between the two groups and other variables were analyzed by the student 's t - test. in addition, pearson 's chi - square test was used to compare frequency and complications. among the 74 patients, 36 in group 1 and 38 in group 2, 12 core prostate biopsies were obtained, and they were enrolled in the study for data analysis. the mean patient age, serum psa, and total prostate volume were similar in the two groups (table 1). twenty six patients (35%) were diagnosed with prostate cancer ; 13 patients were assigned to group 1 (36%), and 13 to group 2 (34%). the mean vas score in patients with pilp cream application prior to the ppnb was lower than that of the patients that did not receive the cream application prior to the ppnb (2.2 vs. 3.0, p=0.001). in addition, there was a difference in the number of patients that had a pain score of three or more : 44% in group 1 and 65% in group 2 (fig. 1, 2). there were only minor complications, such as mild hematuria, mild hematochezia and hemospermia. thirty - three patients had gross hematuria, three patients had hematochezia, and one patient had acute urinary retention. all patients recovered with conservative management ; no patient required hospitalization due to complications including sepsis. although the trus - bx is a standard procedure for prostate cancer detection, turs - bx related pain or discomfort has been reported during the procedure associated with the anorectal probe and puncture of the prostate capsule. evaluated the impact of a prostate biopsy on 211 men and reported that immediate pain or discomfort was reported in 96% and 89% of their patients, respectively. pain during the trus - bx can be attributed to two main factors : anal discomfort due to the ultrasound probe passed into the rectum and the insertion of needles through the prostate gland. mostly, the prostate biopsy - related pain is caused by the needle penetrating the prostate capsule. this method has been clinically applied since 1996 when it was first reported by nash, who suggested that bilateral injections at the junction of the base of the prostate and seminal vesicles provided good pain control. now, periprostatic nerve block with 1% lidocaine is considered the gold standard for analgesic anesthesia before performing an office - based prostate biopsy. the rectum is innervated below the dentate line by the inferior rectal branches of the pudendal nerve. therefore, there are many studies on the efficacy of local anesthetic agents such as lidocaine cream or jelly application. kandirali reported that only perianal anesthesia with lidocaine - prilocaine cream was sufficient to decrease the pain during a trus - bx. stirling reported that the postprocedural pain scores were significantly lower in the group that received 10 ml of 2% lidocaine gel intrarectally compared to the group that received no anesthetic ; in addition, the postprocedural scores for probe insertion were significantly lower in the topical group than in the control group. however, other studies did not confirm the efficacy of intrarectal lidocaine, and in some studies inferior results were obtained compared to the ppnb [11 - 16 ]. now lidocaine gel or cream is used in combination with ppnb rather than either method alone. giannarini reported that the combination of pilp cream and periprostatic nerve block provides better pain control than the cream or the ppnb alone. in korea, one study has investigated the efficacy of a combination of intrarectal lidocaine gel with ppnb. this study showed that the combination of intrarectal lidocaine gel and periprostatic nerve block was effective in reducing pain during repeat prostate biopsies and the pain felt during transrectal probe insertion. a combination of pilp cream and periprostatic nerve block showed less pain than the periprostatic nerve block alone (2.220.89 vs. 3.021.15). the results of this study suggest that the combination of pilp cream and periprostatic nerve block was an effective and useful technique and well tolerated by patients. pilp cream was chosen as the topical anesthesia because, in addition to its established efficacy and rapid absorption, it has been shown to have no side effects in prior studies. in this study, there were no side effects associated with the pilp cream and patient compliance was good. rectal bleeding, hematuria, and hemospermia were self - limited and did not result in hospitalization or the need for additional treatment. lidocaine - prilocaine cream is available at most trus - bx centers, and its use for prostate biopsy procedures is safe and easy. except for the rare patient with allergies to local anesthesia, pilp cream prior to ppnb the study had a small number of patients and there was little difference among the pain scores. after the findings showed less pain in the combination group, pilp cream was applied in all patients undergoing trus - bx. however, to our knowledge, this is the first domestic report on the combined effect of lidocaine - prilocaine cream with ppnb on pain control during trus - bx. a difference was also found in the number of patients with three or more on the pain score, 44% in group 1, and 65% in group 2. a combination of lidocaine - prilocaine cream and a periprostatic nerve block was safe and effective for pain control in patients undergoing turs - bx. a periprostatic nerve block plus lidocaine - prilocaine cream can be considered for patients undergoing turs - bx. | purposeprostate biopsy for diagnosing cancer can be painful. the efficacy and safety of combination perianal - intrarectal lidocaine - prilocaine (pilp) cream and periprostatic nerve block were compared with nerve block alone during transrectal ultrasound guided prostate biopsy (trus - bx).materials and methodsfrom october 2007 to august 2009, 74 men undergoing a transrectal prostate biopsy were randomized into two groups. in group 1, 36 patients received a combination of pilp cream and a periprostatic nerve block ; and in group 2, 38 patients received lubricant jelly and a periprostatic nerve block. thirty minutes later, the trus - bx was performed. pain was evaluated by a 10-point visual analogue scale (vas) after the biopsy.resultspatients in group 1 showed a significantly lower vas score than patients in group 2 (mean score 2.220.89 vs. 3.021.15, p<0.001). in addition, there was a difference in the number of patients that had a pain score of three or more, 44% in group 1, and 65% in group 2. the overall complication rate was similar in both groups (p=0.45).conclusionsa combination of pilp cream and periprostatic nerve block reduced pain compared to the periprostatic nerve block alone. this safe, simple technique can be considered prior to trus - bx to reduce patient discomfort. |
renal cell carcinoma (rcc) is the seventh and eighth most common cancer in men and women respectively. although prevalent utilization of cross - sectional imaging allowed early detection of asymptomatic renal tumors, a significant number of patients present with large and metastatic rcc. the prognosis of metastatic rcc is poor, and most patients die within a year of being diagnosed with metastatic disease. cytoreductive nephrectomy (crn) in patients with advanced rcc is well - recognized for its benefits in palliation and prolonging survival. over the years, various techniques have been described for extirpating tumors of increased size or extensive involvement [3, 4 ]. in addition, complete metastasectomy has been shown to offer a chance of cure to some patients and even incomplete metastasectomy improves survival in others [5, 6 ]. only an autologous renal tumor cell vaccine has proven to be beneficial in a randomized phase iii trial. many studies have been conducted using immunotherapy agents, but most fail to show a benefit in overall survival or disease free survival, however new immunotherapy and chemotherapy agents are currently being investigated. by combining nephrectomy, metastasectomy, and some forms of adjuvant therapy, we may be able to offer patients an approach that can prolong survival with a reasonable quality of life, as evidenced by our case report. we report the case of a 48-year - old hispanic male with a 30 pack - year history of smoking. the patient, who had no prior surgical or medical morbidities, presented with a right upper quadrant abdominal mass and hematuria. computerized tomography (ct) of the abdomen revealed a 14 x 14 cm mass arising from the inferior pole of the right kidney compressing and possibly invading the renal vein and inferior vena cava. metastatic investigations were negative except for multiple 2 - 3 mm calcified nodules in the right lower lobe of the lung. the patient elected to undergo radical nephrectomy using a liver mobilization technique based on orthotopic liver transplantation procedures. liver mobilization minimizes the risk of massive hemorrhage by providing maximal exposure of the right upper quadrant and enabling safe vascular control [9, 10 ]. the renal mass was noted invading the second part of the duodenum, which was also resected. the pathological exam showed grade iii 12 cm rcc with granular and clear cell features with necrosis. the patient subsequently underwent immunotherapy with thalidomide and was subjected to close monitoring of the pulmonary nodules. the basal right lung nodules continued to grow in size and, as a result, the patient underwent a right thoracotomy and lower lobe wedge resection 18 months following crn. the pathology was consistent with clear cell rcc. from 2003 to 2006, the patient was receiving daily chemotherapy in the form of thalidomide. in 2006, the patient was noted to have increased lymphadenopathy in the right lung and was placed on sorafenib. in october of 2008, the patient noted the presence of an enlarging mass in his right cheek. on examination, the patient had a 2 x 2 cm pedunculated mass on the right buccal mucosa. an incisional biopsy identified this mass a rcc and it was subsequently excised. as such simultaneously, a ct scan had shown a lytic lesion of the right posterolateral second rib. repeat pet scan showed foci of hypermetabolic activity in the oropharynx, base of the right lung, several areas of the liver, and the right second rib. in september of 2009, ct revealed that the lytic lesion was enlarging. the temsirolimus therapy was discontinued secondary to a foot infection. in august of 2010, the tumor had reached a size of 81 x 38 mm with no lung involvement. at this point, the patient underwent tumor debulking with right - sided chest wall resection of the second and third ribs. in november, the patient began chemotherapy with pazopanib given the diffuse spread of the tumor. in december of 2010, the patient presented with increasing upper back pain over the previous 6 weeks. magnetic resonance imaging (mri) of the thoracic spine revealed bony metastatic disease involving the t3, t4, and t5 thoracic vertebral bodies with pathological fracture of the t4 vertebra and epidural extension causing cord compression and abnormal signal within the spinal cord spanning the t2 through t4 levels. as a result surgical pathology revealed the tumor to be a metastatic, poorly differentiated carcinoma with spindle cell features in dense fibroconnective tissue with the tumor cells being positive for cd1 and ema, and negative for ck7 and rca, an immunophenotype most consistent with a metastatic renal cell carcinoma. the patient is currently able to work fulltime and is followed by the oncology service on an outpatient basis. it is believed that 30% of patients present with metastasis at the time of diagnosis. of patients presenting with only localized disease, another 20 - 40% of them will present with metastasis after partial or radical nephrectomy. as with all cancers, the presence of metastasis confers a poor prognosis, with a 5-year survival of metastatic rcc of less than 10%. treatment of metastatic rcc is challenging because of resistance to currently available chemotherapy regimens. only complete surgical resection of metastases offers any possibility of definitive therapy in patients. currently, the 5-year survival rate of these patients after metastasectomy is between 30 and 45% [13, 14, 15 ]. also, the risk of death is reduced by more than half with complete resection of all metastases. most of our information comes from patients who have had a solitary metastasis or metastases to the lung ; however, patients who present with multiple metastases, synchronously or metachronously, can also benefit from metastasectomy [5, 13, 14, 15, 16 ]. alt. showed that patients with complete metastasectomy were associated with a significant prolongation of median cancer specific survival (css) (4.8 years vs. 1.3 years ; p < 0.001). the 5-year css was also increased in patients with multiple, nonlung - only metastases who had undergone complete metastasectomy, 32.5% versus 12.4%. even patients who had metachronous multiple metastases had improved 5-year css with complete resection. a case has been documented in the literature of a rcc patient living 11 years after multiple metastasectomy. | we describe the case of a patient with a large renal cell carcinoma (rcc) who underwent cytoreductive nephrectomy utilizing liver mobilization techniques similar to those used in transplantation. despite recurrent metastases, our patient continues to survive eight years later with several metastasectomies and adjuvant chemotherapy.we report the case of a 48-year - old hispanic american man who presented with a 4-month history of an enlarging right upper quadrant abdominal mass and hematuria. computerized tomography revealed a 13 x 14 x 14 centimeter mass suspicious of rcc with possible metastasis to the lungs. the patient subsequently underwent radical nephrectomy. pathological analysis confirmed the mass as rcc. over the following eight years, the patient developed metastases to the pulmonary lobes, buccal mucosa, thoracic spine, and second rib, which were all treated with metastasectomy. the patient continues to survive today with a reasonable quality of life.palliative measures in patients with large rcc tumors with distant metastases require persistent, aggressive therapeutic modalities. |
end stage renal disease (esrd) is a serious health problem among children, especially among children aged < 2 years. it has particular features in terms of etiology and therapeutic modalities. the management of infants with esrd aims, on the one hand, at increasing patients longevity and, on the other hand, at improving growth and life - quality. esrd incidence among children is estimated at 5.5 new cases per million inhabitants per year in europe, 10.6 in canada, and 4 in japan. in developed countries, prognosis of pediatric esrd has improved ; most children can have access to chronic peritoneal dialysis (pd), hemodialysis, or kidney transplantation. conversely, in developing countries, esrd is a serious cause of morbidity and mortality. managing esrd is particularly challenging due to patients late presentation, poor socioeconomic conditions, and inadequate health care infrastructure support. some data found in nigerian series report an incidence of 4 cases / million inhabitants per year. in tunisia, a single epidemiological study, in 1993, examined the esrd epidemiological aspects, since then no data about ersd among infants has ever been collected. the aim of our study was to describe esrd etiologies and outcomes among tunisian infants. this retrospective study included all infants with the esrd diagnosis who presented to the department of pediatric nephrology at charles nicolle hospital in tunis from january 1998 to december 2013. esrd patients were defined as those who needed renal replacement therapy (rrt) to sustain life. we excluded foreign - born patients, those whose death occurred within a short time. individual patient data included date of birth, gender, primary renal disease, starting rrt date, treatment modality at start of rrt, and important events such as death. we studied 157 children with esrd who were treated in the pediatric department at charles nicolle hospital. 24 children (15.2%) were infants ; the sex ratio was equal to 2. the mean age of infants with esrd at presentation was 8 months (range, 121 months). laboratory findings were as follows : mean serum creatinine : 5.6 (3.19) mg / dl, mean blood urea nitrogen : 95 (18243) mg / dl, and hemoglobin : 6 (3.512) g / dl. hypocalcemia was noticed in 13 infants and hyperphosphatemia in 20 infants [table 1 ]. patient 's characteristics at presentation the main causes were congenital anomalies of the kidneys and urinary tract (cakut) (9 infants), inherited renal disease (9 infants), hemolytic and uremic syndrome (3 cases), and unknown origin (3 cases). all patients were treated by pd, all infants had double - cuff straight tenckhoff catheter, 20 infants were treated with continuous ambulatory pd and 4 infants with automated pd ; 17 infants had peritonitis. this study presents esrd etiology and outcome among tunisian infants. to the best of our knowledge, none of the studies have so far focused exclusively on infants with esrd and, therefore, our study adds new insights to esrd etiologies and outcome among tunisian infants. it has particular characteristics in terms of etiology and therapeutic modalities. over the last few years the rising incidence of rrt was attributed to the increase of dialysis provision to younger children by virtue of improvements in techniques for nutritional and dialysis support. the male predominance noted in this study is similar to observations in many other reports. as in the other studies, male predominance is due to the higher proportion of males among patients with cakut. in our series, growth retardation was noticed in 14 patients, but only 9 patients received growth hormone. reports from europe, australia, japan, kuwait, turkey, and the united states show that cakut are the leading causes of esrd and are responsible for between 34% and 52% of esrd cases among children ; esrd in younger children is mostly due to cakut. the high prevalence of inherited renal disease among infants in our study is attributed to the high proportion of consanguinity (58%). environmental, ethnic, and other differences might explain the different occurrences of primary renal diseases in europe and in other parts of the world as compared with our findings. access to chronic rrt has improved the esrd outcome in developed countries. a tunisian research dated 1997 found that the therapeutic abstention rate attained 19%. in our study, all infants received rrt. a korean study reported a frequency equal to 21.7% of peritonitis among infants undergoing pd. a british study published in 2010 reported that the peritonitis incidence was estimated at 66.66%. long - term survival rate for children with chronic rrt in developed countries is 79% at 10 years and 66% at 20 years. major death causes identified in this study were infections, followed by cardiovascular causes as is reported in the literature. in tunisia, management of children with esrd has known progress in recent years ; yet, mortality rate in infants with esrd is high. the current high rate of mortality can be improved by earlier referral, better nutrition, family support, and enhanced access to treatment modalities. | end stage renal disease (esrd) in infants has particular features in terms of etiologies and therapeutic modalities. the aim of our study is to describe the etiologies and the esrd outcomes among tunisian infants. this retrospective study was conducted over 15 years (from january 1998 to december 31, 2013) in the pediatric department at charles nicolle hospital. in total, 157 pediatric patients had esrd. the mean incidence was 4.25 million children. the study involved 24 infants ; the sex ratio was equal to 2. the mean age at diagnosis of esrd was 8 months (range, 121 months). growth retardation was noticed in 14 patients. the main causes were congenital anomalies of the kidneys and urinary tract (9 infants) and hereditary renal disease (9 infants). all patients were treated with peritoneal dialysis ; 16 infants presented peritonitis. mortality rate was about 28%. the leading causes of death were cardiovascular diseases and infections. |
the ebola haemorrhagic fever (ebola hf) also known as ebola virus disease (evd), is an acute viral haemorrhagic illness caused by filoviridae family.1 ebola viral fever, a highly contagious haemorrhagic disease has today become a major public health concern in the developing countries worldwide. since 1976, there have been 885,343 suspected and laboratory confirmed cases of ebola hf in west africa. this part of the world is persistently confronted with this fatal disease which has an incubation period of 2 - 21 days (average 3 - 13days).2 symptoms range from, firstly, fever and fatigue before descending into headaches, vomiting, violent diarrhoea, then multiple organ failure and massive internal bleeding.3 ebola typically begins in remote places and can be distributed via hospitals / health care centers or within the community as it takes several infections before the disease is ascertained. the prevalence, morbidity and case fatality of chronological ebola hf outbreaks showed the persistent resurgence in different regions in sub - saharan africa.2 ebola hf outbreaks have a case fatality rate of 50 - 90%, yet no specific drug or vaccine is available for people and/or animals hosts.4 as of september 6 2014, the cumulative number of cases attributed to ebola hf in the five west african countries stands at 4293.5 new cases are still occurring as there is no standard treatment for ebola hf.6 first time in the history of world a disease has been so dreaded that it has threatened the existence of any nation, as told by liberian defense minister to the united nations security council in liberia where, more than 1000 person have died of ebola hf including more than 80 health workers.7 health care workers are at a greater risk of contacting such diseases and may also promote their transmission by occupational exposures.8 transmission in health care settings has been associated frequently with ebola hf outbreaks in africa. if cases of the disease do appear, care must be taken to avoid the spread of the disease within health - care facilities. patients must be isolated from contact with any unprotected people and hospital workers must wear protective clothing, such as masks, gloves, gowns and goggles.9 being a highly contagious disease ebola hf can spread to other parts of the world because of continuous movement of people in different parts of the world so it becomes necessary for the clinicians who come in contact with patients to be, aware of this highly fatal disease. india being a developing country with high population density and various lifestyle among the folks make india prone towards any type of epidemics so also to ebola hf. the practice of dentistry exposes dentists to a variety of microorganisms that are transmittable via blood, oral or respiratory secretions.10 hence, dentists should have sound knowledge on the prevalent infectious diseases, their symptoms, modes of spread and methods of prevention. the purpose of this study was to assess the knowledge of dental practitioners towards ebola hf in tricity, india. this cross - sectional survey was conducted in the months of july and august 2014 in tricity. the study protocol was approved by the institutional ethical and review committee of swami devi dyal hospital and dental college (dated : 2014, june 2). list of private dental practitioners was obtained from the respective indian dental association branches across chandigarh, panchkula and mohali. from the list, a total of 500 private dental practitioners were randomly approached to participate in the survey. a written informed consent was obtained after explaining about the aims and the objectives of the study. a self - structured, closed ended questionnaire was administered to each participant in person, which took approximately 5 minutes to complete both sections. survey reports were kept anonymous and participants confidentiality was assured. the original version of the questionnaire was pilot tested in order to determine the test - retest reliability of the survey questions, fifteen private dental practitioners who completed the survey during the initial administration, completed the survey two weeks later. the respondents were also asked for feedback on clarity of the questions and whether there were difficulty in answering the question or ambiguity as to what sort of answer was required. the subjects who participated in the pilot study were not included in the final sample. few modifications were done to improve the understanding of the questionnaire based on the responses. final questionnaire consisted of two parts : section - a, consisted of questions assessing demographic and professional characteristics like age, gender, location, qualification and years of clinical practice while section - b included questions about knowledge of ebola hf. knowledge section (17 questions) included questions regarding communicability ; symptomatology and diagnostics ; at - risk individuals ; prevention and treatment ; and, virus characteristics of ebola hf. the responses to these questions were of multiple - choice type having one correct answer, including an option of do n't know in some of questions. multivariable linear regression analysis was carried out to assess the association of participants 's demographic and professional characteristics with the knowledge scores. all significance tests were two tailed and p - value of less than 0.05 was considered to be statistically significant. all analysis were done using the statistical package of social sciences 17.0 software (spss inc., multivariable linear regression analysis was carried out to assess the association of participants 's demographic and professional characteristics with the knowledge scores. all significance tests were two tailed and p - value of less than 0.05 was considered to be statistically significant. all analysis were done using the statistical package of social sciences 17.0 software (spss inc., out of the 500 dentists who were approached to participate in the survey, 436 agreed and completed the questionnaire. majority of the subjects belonged to the age - group of 25 - 35 years (48.2%), were females (68.9%) with less than 5 years of clinical practice (53.2%), had a bachelor 's degree in dentistry (74%) and belonged to urban areas (89.1%). demographic and professional characteristics of the participants of the study the mean (also the median) knowledge score of the respondents was 23.84 5.12. knowledge among study participants regarding ebola hf ebola hf as a disease of viral origin was known to 80.9% of the participants, however, only 35.4% of the subjects were conscious of the fact that the infected person spread virus to others within 7 weeks after recovery from illness. very few (37.1%) majority (77.1%) were having knowledge that its outbreaks occur primarily in central and west africa. seventy eight percent were aware of fever, intense weakness, muscle pain and internal and external bleeding as the symptoms of ebola hf. availability of diagnostic tests during an outbreak that is pcr and elisa were known to only 37.9%. multivariable linear regression analysis was carried out to find out the determinants of knowledge among the study participants. of the five demographic and professional characteristics (age, gender, location, qualification and years of clinical practice) incorporated into the model, only location and qualification of the participant contributed significantly to the knowledge score indicating that participants, who are from urban areas and with a higher qualification had better knowledge (p < 0.05) [table 3 table 4 ]. responses to the knowledge questions regarding ebola hf by the participants of the study association between the demographic and professional characteristics of the participants with the knowledge scores using multivariate linear regression analysis television and newspaper were the main sources of information followed by the professional colleagues, relatives / family members, friends and radio [table 5 ]. the public health significance of the disease, ebola hf, lies not only in its potential to cause significant mortality and morbidity at community level, especially during outbreaks, but also its potential for nosocomial spread. maintaining a high index of suspicion should only be based on adequate knowledge of the disease among the care providers. also effective patient counselling and community campaigns can only be held out by health workers who are themselves adequately informed about the disease. it is thus important that health workers be conversant with the disease manifestations, management, prevention and also cross infection as well, that can be from a patient to dentist, from dentist to patient or from patient to patient as well.1112 thus this survey was carried out to provide a coherent description of dentists knowledge and position in this territory in regard to the ebola hf and such an agreement is important to evaluate their effectiveness in the prevention of such infectious diseases.13 according to centers for disease control and prevention (cdc), the period of infectivity of ebola virus begins the day before the onset of illness and can persist for up to 2 - 21 days after exposure to ebola virus though 8 - 10 days is most common. it is of concern that in our study dentists lacked sufficient knowledge about the period of infectivity and duration of viability of the virus (35.4%).3 the results of the knowledge level test among the respondents to our questionnaire, (which had questions pertaining to the communicability ; symptoms and diagnostics ; prevention and treatment ; and, virus characteristics of ebola hf), suggest that knowledge among the dentists was fairly good (25 percentile value exceeded 55% of the highest knowledge score). however, there were some noteworthy yet disturbing gaps in knowledge at some places like for example knowledge regarding virus characteristics, infectivity period, diagnostic techniques available and virus elimination. although who has provided documentation regarding ebola hf investigation and control but only nearly half of the respondents that is 52.2% were aware of this, so dentists should need to regularly update their knowledge regarding epidemics and such diseases which will inculcate positive attitude and healthy practices in them. in the present study the post graduate dental practitioners were found to have better knowledge scores than their graduate counterparts. this could be the reflection of regular upgradation of knowledge through scientific journals and other available electronic data which the postgraduate practitioners are well versed with since their post graduation times. it was also found that the dentists practicing in urban areas were found to have significantly higher knowledge scores than those who were practicing in peri urban areas. as more number of dental education programmes and conferences are held in urban areas, this gives advantage to urban practitioners to regularly update their knowledge about various fields including the prevention and spread of any infectious disease. in nellore, india.4 when comparison was made based on the gender, similar knowledge scores were found between the males and females which is in contradiction with the studies conducted by kamate., and leili.1415 this shows that females in this region are equally interactive and as social as males and also they are equally concerned about increasing their knowledge banks. audio - visual aids were the most important source of information for ebola hf followed by visual aids, family members and fellow colleagues. this could be because of increase in the number of news channels, daily broadcasting of the events pertaining to public health significance and special discussion programmes with the experts about the spread and prevention of this disease. this finding was similar to with the study conducted by and apichaya, where television was the most important source of information for the public.6 the participants of this study constituted the convenient sampling so the sample may not be a representative one, however, to remove this limitation we do tried to incorporate as many as possible practitioners. another thing to be mentioned is that only the knowledge scores have been considered here because it 's a too early stage to assess the attitudes and practices in relation to ebola hf, when very less is known about this disease. nevertheless this study do opens new vistas for future researchers around the world, as this is one of its kind studies in dental and medical literature assessing the knowledge regarding ebola hf. how exactly people are infected with ebola hf and also there are very few established primary prevention measures. when the cases appear, there is increased risk of transmission within medical and dental health care settings. therefore, health care providers should be able to identify a case of ebola hf and be ready to employ precautions or practical barrier nursing techniques. they should further be capable of requesting diagnostic tests or prepare samples for shipping and testing elsewhere.3 through this study it was found that dentists knowledge regarding ebola hf was fairly good. participants from urban areas with higher qualification had better knowledge yet there were notable deficiencies regarding the virus characteristics, diagnostics, elimination and treatment. emphasis should be given to create a perception towards public health significance of diseases as well as more number of continued dental education programmes should be carried out to disseminate the knowledge effectively regarding ebola hf and other such highly infectious and fatal diseases. | background : ebola viral fever, a highly contagious haemorrhagic disease has today become a major public health concern in the developing countries worldwide.aim:the purpose of this study was to assess knowledge among dental practitioners regarding ebola haemorrhagic fever (ebola hf) in tricity, (chandigarh, panchkula and mohali).materials and methods : a total of 500 private dental practitioners were randomly approached to participate in this cross - sectional survey. a self - structured, closed ended questionnaire was administered to each participant to record demographic and professional characteristics followed by their knowledge regarding ebola hf. knowledge section included questions related to communicability ; symptomatology and diagnostics ; at - risk individuals ; prevention and treatment ; and, virus characteristics of ebola hf.results:the results were expressed in percentages. multivariable linear regression analysis was carried out to assess the association of participants 's demographic and professional characteristics with the knowledge scores. statistically significant difference was seen when mean knowledge scores were compared based on the locality and qualification of the participants (p < 0.05).conclusion : dental practitioners from urban areas with higher qualification had better knowledge yet there were notable deficiencies regarding the virus characteristics, diagnostics, elimination and treatment. |
diabetic ketoacidosis (dka) is an acute complication of diabetes mellitus and is characterized by excessive production of betahydroxybutyric and acetoacetic acids leading to low blood ph. an arterial ph of less than 7.3 is required in order to diagnose dka. rarely, because of other complicating factors, blood ph may be in the alkalemic range and the term diabetic ketoalkalosis has been coined to describe this condition. currently, less than 30 such cases have been reported in the literature. a 34-year - old woman was admitted to the emergency department of nemazee hospital, shiraz university of medical sciences, because of polyuria and polydipsia. one year prior to admission she had underwent pancreas transplantation with pancreatoduodenal anastomosis because of repeated episodes of hypoglycemia, diabetic ketoacidosis, and poor diabetic control. after transplantation, she was on immunosuppressant drugs such as mycophenolate mofetil (cellcept) and tacrolimus (prograf) and had normal blood sugar. she discontinued her immunosuppressant drugs from 2 weeks prior to admission and gradually developed polyuria and polydipsia. at the time of admission to the emergency room her laboratory data were as follows : blood sugar : 385 mg / dl, blood ph : 7.41, bicarbonate : 22 meq / l, bun : 28 mg / dl, creatinine : 1.1 ng / ml, k : 3.9 meq / l, na : 138 meq / l, negative urine ketone, and 3 + glucosuria. her immunosuppressant drugs were restarted and she received one pulse of 1000 mg methylprednisolone. during the next 72 hours she received an intravenous infusion of 4 units regular insulin per hour. however, her blood sugar remained high and she had repeated episodes of vomiting and had diffuse abdominal pain and extremity weakness. because of her deteriorating condition, she was transferred to the intensive care unit (icu). at the time of her icu admission, her vital signs were as follows : temp : 36.5c orally, blood pressure : 100/70 mmhg, pr : 110/min, and rr : 34/min. her initial laboratory data showed : hb:13.5 g / dl, wbc : 18500/ml, 80% pmn, blood sugar : 385 mg / dl, bun : 32 mg / dl, creatinine : 1.3 ng / ml, na : 144 meq / l, k : 2.5 meq / l, blood ph : 7.50, paco2 : 32 mmhg, bicarbonate : 25 meq / l, chloride : 92 meq / l, serum albumin : 4.2 g / dl, globulin : 2.1 gd / l, calcium : 9.2mg / dl, and magnesium : 1.6mg / dl. the patient was diagnosed as having dka and mixed metabolic acidosis and metabolic and respiratory alkalosis. because of her hypokalemia, she received 40 meq potassium chloride and normal saline during the first hour of treatment. the routine treatment of dka was started with 10 units of regular insulin per hour. during the first 4 hours of treatment, her alkalosis progressed to a ph of 7.64. her nausea, vomiting, and abdominal pain subsided after 5 hours of treatment and her serum ketone became negative after 8 hours. she was able to eat after 14 hrs and 2 days later she was discharged on insulin (twice daily). because of her undetectable c - peptide level, she was diagnosed as a case of pancreas transplant failure and her immunosuppressant drugs were discontinued. our patient had strongly positive serum ketone, but at the same time her blood ph was in the alkalemic range of 7.5. this alkalemic ph in our patient can be explained by the presence of mixed acid - base disturbance. if the patient had pure metabolic acidosis, the serum bicarbonate was expected to drop to 11 meq / l. the serum bicarbonate in our patient had failed to decrease which signifies the presence of concomitant metabolic alkalosis. in our patients, repeated vomiting and the effect of a high dose of methylprednisolone were two causes for metabolic alkalosis. moreover, the expected arterial paco2 is 40 mmhg, but our patient had an arterial paco2 of 32 mmhg, reflecting the presence of respiratory alkalosis. pain and anxiety can be the causes of respiratory alkalosis in this patient. as expected, treatment of dka led to the progression of alkalosis, but with therepletion of water and electrolytes, plasma ph gradually returned normal. in most previously reported cases the main causes of dka were hypovlemia because of vomiting and use of diuretics, and alcohol ingestion. use of diuretics and repeated vomiting result in electrolyte depletion and hypovolemia, leading to bicarbonate reabsorption and alkalosis. two cases of endogenous cushing s syndrome because of adrenal adenoma and ectopic adrenocorticotropin (acth) production with dka have also been reported. excess endogenous or exogenous glucocorticoids can promote h excretion from the kidneys by their effect on mineralocorticoid receptor and contribute to alkalosis. respiratory alkalosis, as in our patient, has also been implicated as a contributing factor. vomiting and hypercortisolemia caused by steroid pulse therapy were the causes of dka in our patient. we conclude that a normal or even alkalemic blood ph does not rule out the presence of dka. in order to prevent delayed diagnosis and treat this potentially fatal condition, attention should be paid to the changes in plasma anion gap and bicarbonate and the presence of ketonemia. | diabetic ketoacidosis (dka) is characterized by excessive production of organic acids leading to a low blood ph. rarely, because of other complicating factors blood ph may be in the alkalemic range and the term diabetic ketoalkalosis has been coined to describe this condition. so far, less than 30 such cases have been reported in the literature. we report a 34-year - old woman who received methylprednisolone pulse therapy for the treatment of pancreas transplant rejection. thereafter, she developed vomiting and abdominal pain. her laboratory data showed high blood sugar, hypokalemia, alkalemic ph, elevated plasma anion gap, and significant ketonemia. she responded well to the treatment of dka. it was concluded that an alkalemic ph does not rule out the presence of ongoing dka. in suspected cases, changes in plasma anion gap and bicarbonate and the presence of ketonemia should be noted. |
although the development of efficient antiretroviral treatment options has changed the face of the aids epidemic in industrialized countries, opportunistic infections like toxoplasmic encephalitis or pneumocystis pneumonia still present a considerable challenge [1 - 3 ]. especially in patients in a late stage of hiv infection, symptoms of aids - defining diseases are a common reason for first hospital admission [4 - 6 ]. while detailed treatment guidelines exist for most opportunistic infections, the situation regarding toxoplasmosis is more difficult. especially the question when to initiate antiretroviral treatment in order to avoid immune reconstitution problems, and when to stop the anti - infective therapy remains open in most guideline reviews. one reason for this may be the significantly lower incidence of toxoplasmic encephalitis in the usa compared with european countries [8 - 10 ]. only scarce data about immunological and virological response to highly active antiretroviral therapy initiated in patients treated for toxoplasmosis observation of such patients in the clinical setting led to the hypothesis of an impaired cd4lymphocyte response to art. to further investigate this hypothesis we used the database of the " clinsurv hiv " cohort, a multicentre cohort of 17 german hiv clinics led by the robert koch institute in berlin. the data reported biannually includes clinical and laboratory parameters, patient demographics, transmission route, date of hiv - diagnosis, clinical stage, aids related or aids defining diseases, antiretroviral treatment and date of death. we retrospectively searched this database for patients who matched the following criteria : diagnosis of either toxoplasmic encephalitis or pneumocystis pneumonia in the period between january 1999 and december 2005 ; art - nave ; initiation of art in the 2 months following the oi - diagnosis ; sufficient documentation of art - regimen, viral load and cd4t - cell count (defined by at least three measurements of each laboratory parameter) in the 12 months following art - initiation ; and a cd4lymphocyte count below 200/l at baseline. pcp - cases were chosen as a control group due to the hypothesis that this group would provide a sufficient number of patients with a comparably impaired immunologic status. diagnosis of pcp was established by detection of pneumocystis jiroveci in the broncho - alveolar lavage. toxoplasmosis was diagnosed by brain imaging, clinical signs, serology and response to anti - toxoplasma treatment according to the european aids case definition and the cdc " 1993 revised classification system for hiv infection and expanded surveillance case definition for aids among adolescents and adults ". the two groups were compared regarding their demographic characteristics, baseline viral load and cd4/cd8t - cell count, as well as virological and immunological response in the first 12 months of art. every laboratory test performed in this period was assigned to a one - month - window (m1, m2, m3... and m12) and in a second step, because of the high amount of missing values, to a three - month - window (quarter q1, q2, q3 and q4) starting from the date of art - initiation. for windows containing more than one value an arithmetic mean was calculated. if a window contained viral - load values both below detection limit (< 50 copies / ml) and above, only the latter were taken into account. virological response to art was compared using cross tables and chi - squared test for percentage of patients with a vl below the limit of detection after 6 and 12 months of art and performing kaplan - meier survival analysis for time to viral load suppression (defined by two consecutive vl - measurements < 50 cop / ml). mean values of absolute cd4lymphocyte count, total lymphocytes and deltacd4 (increase in cd4t - cells in comparison to baseline) were compared by t - test. in order to look at a more clinically relevant parameter for a positive antiretroviral treatment outcome, immunological response was defined as reaching a cd4lymphocyte count of 200/l or higher and compared performing a kaplan - meier analysis regarding time to this event. a uni - and multivariate analysis of factors with possible influence on the probability of immunological response in q2 was performed. therefore the odds ratios as estimators of the relative risk to reach immunological response were calculated using cross tables (univariate) and logistic regression analysis (multivariate). the multivariate analysis adjusted for age and sex and included all factors with a p < 0.2 in the univariate analysis. a total of 257 patients within the clinsurv data set of 17,521 patients enrolled in the cohort at time of data collection met the selection criteria : 61 with diagnosis of toxoplasmosis, and 196 with diagnosis of pneumocystis pneumonia (see table 1 for details). no significant differences were shown for age, proportion of patients with migration background, date of art - initiation, baseline cd8-cell - count and total lymphocyte count. overview of baseline characteristics in the compared groups ; sd = standard deviation, msm = men who have sex with men, hpc = patients from countries of high hiv prevalence, art = antiretroviral therapy, iqr = interquartile range, nnrti = antiretroviral regimen based on nnrti, pi = antiretroviral regimen based on pi, nrti or nnrti / pi = antiretroviral regimen either consisting of nrti only or including nnrti and pi ; p - values calculated by t - test, chi - squared or mann - whitney - u test the percentage of female patients in the te - group was significantly higher than in the pcp - group. the distribution of patients over the different hiv transmission risk categories also diverged significantly, especially with regards to the proportion of men who have sex with men (msm) and patients from countries of high hiv - prevalence (hpc). in both groups, art - regimens based on a boosted protease inhibitor (pi) were chosen as first line antiretroviral treatment in more than 60% of the cases, followed in frequency by non - nucleoside reverse transcriptase inhibitor (nnrti) based regimens. an unusually high amount of pcp - patients was initially treated with a combination including both pi and nnrti. almost 50% of the te - patients started antiretroviral treatment within a month after oi - diagnosis, while in over 60% of the pcp - group art - initiation was delayed until the 1month after diagnosis. the te - patients in this analysis showed a higher absolute and relative cd4-cell count at baseline compared to the pcp - group. at the same time the baseline viral load was significantly lower in the te - group. virologic response to art was comparable in both groups ; not only regarding the percentage of patients with viral load below detection limit after 6 (68.4% vs. 77.5%, p = 0.279) and 12 months (87.5% vs. 77.5%, p = 0.369), but also comparing both groups in regards to " time to the second consecutive hiv - pcr with a result of < 50 cop / ml ". the kaplan - meier analysis showed a median time to this event of 8 months in both groups (p = 0.919, log - rank test). absolute cd4lymphocyte count, delta - cd4, and total lymphocyte count were numerically lower in the te - group in all 4 quarters. in q1, te - patients showed a significantly lower absolute cd4lymphocyte count (129.1/l vs. 163.6/l, p = 0.043) as well as a reduced cd4t - cell increase (+ 74.4/l vs. + 120.3/l, p = 0.006) and less total lymphocytes (1,205.3/l vs. 1,669.4/l, p < 0.001). in the 2and 4quarter, only delta - cd4 and total lymphocyte count remained significantly impaired in the te - group (see figure 1). course of mean absolute cd4-cell count, delta - cd4 and total lymphocytes through the four quarters of the observation period ; te patients show reduced values in all three parameters. = p < 0.05. the percentage of te - patients reaching an average cd4lymphocyte count of at least 200/l was well below that of pcp - patients in q1 and q2, while in the second half of the observation period this difference seems to disappear (see figure 2). a kaplan - meier analysis comparing time to the event " first absolute cd4lymphocyte count 200/l " showed a non - significant advantage for the pcp - group with a median time to event of 8 months (vs. 10 months in the te - group, p = 0.269, log - rank test). lower proportion of te patients with immunologic response, defined as average cd4-cell count 200/l, in q1 (19.3% vs. 29.3%, p = 0.135) and q2 (20.3% vs. 34.1%, p = 0.047, calculated by chi - squared test). to identify other factors possibly related with reduced immunological response, uni- and besides te (vs. pcp) they included the factors age, gender, msm, hpc, pi- and nnrti - based first - line art - regimen, date of art - initiation, baseline viral load and baseline cd4t - cell count. of all these factors only diagnosis of toxoplasmosis and a baseline cd4lymphocyte count below 50 cells/l were associated with a significantly lower probability of reaching the defined cd4goal of 200/l in q2. this effect remained also significant in the multivariate analysis adjusting for age, sex and date of art - initiation (as the only factor with a p < 0.2 in the univariate analysis) (see table 2). uni - and multivariate analysis showing significant influence on immunologic response, here defined as average cd4cell count 200/l in q2, only for the factors te and baseline cd4 < 50/l a total of 257 patients within the clinsurv data set of 17,521 patients enrolled in the cohort at time of data collection met the selection criteria : 61 with diagnosis of toxoplasmosis, and 196 with diagnosis of pneumocystis pneumonia (see table 1 for details). no significant differences were shown for age, proportion of patients with migration background, date of art - initiation, baseline cd8-cell - count and total lymphocyte count. overview of baseline characteristics in the compared groups ; sd = standard deviation, msm = men who have sex with men, hpc = patients from countries of high hiv prevalence, art = antiretroviral therapy, iqr = interquartile range, nnrti = antiretroviral regimen based on nnrti, pi = antiretroviral regimen based on pi, nrti or nnrti / pi = antiretroviral regimen either consisting of nrti only or including nnrti and pi ; p - values calculated by t - test, chi - squared or mann - whitney - u test the percentage of female patients in the te - group was significantly higher than in the pcp - group. the distribution of patients over the different hiv transmission risk categories also diverged significantly, especially with regards to the proportion of men who have sex with men (msm) and patients from countries of high hiv - prevalence (hpc). in both groups, art - regimens based on a boosted protease inhibitor (pi) were chosen as first line antiretroviral treatment in more than 60% of the cases, followed in frequency by non - nucleoside reverse transcriptase inhibitor (nnrti) based regimens. an unusually high amount of pcp - patients was initially treated with a combination including both pi and nnrti. almost 50% of the te - patients started antiretroviral treatment within a month after oi - diagnosis, while in over 60% of the pcp - group art - initiation was delayed until the 1month after diagnosis. the te - patients in this analysis showed a higher absolute and relative cd4-cell count at baseline compared to the pcp - group. at the same time the baseline viral load was significantly lower in the te - group. virologic response to art was comparable in both groups ; not only regarding the percentage of patients with viral load below detection limit after 6 (68.4% vs. 77.5%, p = 0.279) and 12 months (87.5% vs. 77.5%, p = 0.369), but also comparing both groups in regards to " time to the second consecutive hiv - pcr with a result of < 50 cop / ml ". the kaplan - meier analysis showed a median time to this event of 8 months in both groups (p = 0.919, log - rank test). absolute cd4lymphocyte count, delta - cd4, and total lymphocyte count were numerically lower in the te - group in all 4 quarters. in q1, te - patients showed a significantly lower absolute cd4lymphocyte count (129.1/l vs. 163.6/l, p = 0.043) as well as a reduced cd4t - cell increase (+ 74.4/l vs. + 120.3/l, p = 0.006) and less total lymphocytes (1,205.3/l vs. 1,669.4/l, p < 0.001). in the 2and 4quarter, only delta - cd4 and total lymphocyte count remained significantly impaired in the te - group (see figure 1). course of mean absolute cd4-cell count, delta - cd4 and total lymphocytes through the four quarters of the observation period ; te patients show reduced values in all three parameters. = p < 0.05. the percentage of te - patients reaching an average cd4lymphocyte count of at least 200/l was well below that of pcp - patients in q1 and q2, while in the second half of the observation period this difference seems to disappear (see figure 2). a kaplan - meier analysis comparing time to the event " first absolute cd4lymphocyte count 200/l " showed a non - significant advantage for the pcp - group with a median time to event of 8 months (vs. 10 months in the te - group, p = 0.269, log - rank test). lower proportion of te patients with immunologic response, defined as average cd4-cell count 200/l, in q1 (19.3% vs. 29.3%, p = 0.135) and q2 (20.3% vs. 34.1%, p = 0.047, calculated by chi - squared test). to identify other factors possibly related with reduced immunological response, uni- and besides te (vs. pcp) they included the factors age, gender, msm, hpc, pi- and nnrti - based first - line art - regimen, date of art - initiation, baseline viral load and baseline cd4t - cell count. of all these factors only diagnosis of toxoplasmosis and a baseline cd4lymphocyte count below 50 cells/l were associated with a significantly lower probability of reaching the defined cd4goal of 200/l in q2. this effect remained also significant in the multivariate analysis adjusting for age, sex and date of art - initiation (as the only factor with a p < 0.2 in the univariate analysis) (see table 2). uni - and multivariate analysis showing significant influence on immunologic response, here defined as average cd4cell count 200/l in q2, only for the factors te and baseline cd4 < 50/l our analysis shows that immunological response to art initiated in patients with diagnosis of toxoplasmosis is impaired when compared to patients with pcp. this difference comprises lower absolute cd4lymphocyte counts and delta - cd4, as well as a significantly reduced probability of reaching 200 cd4tcells/l in the second quarter of the observed first year under art. this negative effect gets weaker (and disappears) in the second half - year period following the start of art. the observed lower cd4lymphocyte count seems to derive mainly from a reduced total lymphocyte count in the te - group. a plausible explanation could be the known myelosuppressive side effects of anti - infective agents used as recommended standard treatment for toxoplasmosis (pyrimethamine) [13 - 15 ]. the substitution of folic acid routinely provided during te - therapy with pyrimethamine only partially prevents this side effect. the standard pcp treatment with cotrimoxazole can impair the bone marrow as well, but it has a smaller myelosuppressive potency than pyrimethamine, furthermore the suggested duration of pcp - therapy is shorter than for te. if this conclusion will prove correct in further studies, guidelines suggesting a solely cd4-cell guided duration of maintenance therapy would have to be reviewed, in order to avoid a sort of " vicious circle " : low cd4t - cell count leads to ongoing pyrimethamine - treatment leads to low cd4t - cell count etc. have already showed that with sustained viral load suppression the termination of secondary pcp - prophylaxis should be possible also for patients with a cd4-cell count below 200/l. another consequence should be an intensified search for alternative anti - toxoplasmosis drugs with less hematotoxic side effects [18 - 21 ], as well as strategies to directly enhance cd4lymphocyte increase, always considering the possibility of multiple drug interactions in this setting of extensive treatment. a less probable reason for the observed difference would be a direct interaction of the opportunistic infection with the immune system, for example by suppressing myelopoiesis, as it has been shown for generalized infection with mycobacterium avium complex (mac) [25 - 27 ]. a similar myelosuppressive effect caused by toxoplasma has been demonstrated in the acute infection in mice. finally, the use of corticosteroids in initial pcp - therapy could be proposed as a reason for higher cd4-cell counts. there have been reports from small hiv - patient populations showing an increase in cd4-cells when patients were treated with prednisolone. as exact data about steroid use in both groups due to the retrospective nature of the clinsurv cohort, the authors could not confirm each diagnosis of te / pcp by assessing the diagnostic procedures that were applied. diagnosis was performed by the clinicians at the treatment centers who were asked to report only cases of confirmed te / pcp diagnosis, established according to the above mentioned guidelines. especially for te a bias due to incorrectly diagnosed oi can not be ruled out. as mentioned above the compared groups significantly diverged along the following baseline characteristics : gender, hiv - transmission group, first line art - regimen, time from oi diagnosis to art - initiation, baseline cd4lymphocyte count and viral load. these differences are difficult to explain and may mainly result from the low number of cases or from a bias due to incorrectly diagnosed oi. a reason for the higher percentage of patients from hpc in the te - group could be a higher seroprevalence of toxoplasma gondii in hot and humid regions and countries with lower hygiene standards. an explanation for the uncommon choice of first - line art in the pcp group (18.9% pi / nnrti containing regimen) may be a higher baseline viral load and lower baseline cd4lymphocyte count in that treatment - group (log10vl 5.21 vs. 4.82 cop / ml, p = 0.007, cd436.9 vs. 50.8/l, p = 0.075, compared to all patients with different first - line art) as rationale for a more intense art - regimen. the different time to art - initiation may have its cause in the treatment guidelines : waiting until the initial anti - infective treatment shows clinical response is suggested for several oi including pcp, while for toxoplasmosis clear indications for the ideal time to start with art are missing in the guidelines. in a sensitivity analysis adjusting for all these factors, the above mentioned influence of a low cd4t - cell count (< 50/l) on the probability of reaching 200 cd4/l proved highly significant, " te " only marginally missed significance - level in this analysis (p = 0.059). regarding the differences in baseline vl and cd4cell count, there is some evidence that a lower viral load and/or a lower cd4-cell count before starting art is associated with a higher risk of discordant immunologic and virologic response to treatment. this leaves us with the dilemma that, on the one hand, the lower baseline viral load in the te group could have led to the impaired cd4-cell increase in this group, while on the other hand the higher baseline cd4-cell count in the te patients should have had the opposite effect. data collection for the clinsurv cohort consists of a preselected catalogue of parameters. this catalogue does not necessarily take into account all information which could have been of interest for some of the questions this retrospective analysis brought up. not recorded were data like the kind and duration of anti - infective treatment or art adherence. further, as clinsurv is an observational cohort, data collection is not connected to predefined follow - up time points. therefore laboratory parameters like cd4lymphocyte count or viral load are measured in very divergent intervals. the only inclusion criteria regarding quantity of laboratory data for this analysis were a minimum of three cd4t - cell count and viral load measurements performed during the observation period. consequently some of the patients contribute information to the analysis only for part of the year observed. furthermore calculating averages for quarters with more than one lab value could have led to a bias by overrating single values. excluding patients with missing values for one or more of the four quarters the minimum quantity of measurements could have led to a selection bias towards patients with favorable courses of their diseases, taking into account that none of the selected patients died during the one - year follow - up period. due to the retrospective nature of the clinsurv cohort, the authors could not confirm each diagnosis of te / pcp by assessing the diagnostic procedures that were applied. diagnosis was performed by the clinicians at the treatment centers who were asked to report only cases of confirmed te / pcp diagnosis, established according to the above mentioned guidelines. especially for te a bias due to incorrectly diagnosed oi can not be ruled out. as mentioned above the compared groups significantly diverged along the following baseline characteristics : gender, hiv - transmission group, first line art - regimen, time from oi diagnosis to art - initiation, baseline cd4lymphocyte count and viral load. these differences are difficult to explain and may mainly result from the low number of cases or from a bias due to incorrectly diagnosed oi. a reason for the higher percentage of patients from hpc in the te - group could be a higher seroprevalence of toxoplasma gondii in hot and humid regions and countries with lower hygiene standards. an explanation for the uncommon choice of first - line art in the pcp group (18.9% pi / nnrti containing regimen) may be a higher baseline viral load and lower baseline cd4lymphocyte count in that treatment - group (log10vl 5.21 vs. 4.82 cop / ml, p = 0.007, cd436.9 vs. 50.8/l, p = 0.075, compared to all patients with different first - line art) as rationale for a more intense art - regimen. the different time to art - initiation may have its cause in the treatment guidelines : waiting until the initial anti - infective treatment shows clinical response is suggested for several oi including pcp, while for toxoplasmosis clear indications for the ideal time to start with art are missing in the guidelines. in a sensitivity analysis adjusting for all these factors, the above mentioned influence of a low cd4t - cell count (< 50/l) on the probability of reaching 200 cd4/l proved highly significant, " te " only marginally missed significance - level in this analysis (p = 0.059). therefore, the risk of a bias caused by these differences should be negligible. regarding the differences in baseline vl and cd4cell count, there is some evidence that a lower viral load and/or a lower cd4-cell count before starting art is associated with a higher risk of discordant immunologic and virologic response to treatment. this leaves us with the dilemma that, on the one hand, the lower baseline viral load in the te group could have led to the impaired cd4-cell increase in this group, while on the other hand the higher baseline cd4-cell count in the te patients should have had the opposite effect. this catalogue does not necessarily take into account all information which could have been of interest for some of the questions this retrospective analysis brought up. not recorded were data like the kind and duration of anti - infective treatment or art adherence. further, as clinsurv is an observational cohort, data collection is not connected to predefined follow - up time points. therefore laboratory parameters like cd4lymphocyte count or viral load are measured in very divergent intervals. the only inclusion criteria regarding quantity of laboratory data for this analysis were a minimum of three cd4t - cell count and viral load measurements performed during the observation period. consequently some of the patients contribute information to the analysis only for part of the year observed. furthermore calculating averages for quarters with more than one lab value could have led to a bias by overrating single values. excluding patients with missing values for one or more of the four quarters would have led to a substantial loss of information. on the other hand the minimum quantity of measurements could have led to a selection bias towards patients with favorable courses of their diseases, taking into account that none of the selected patients died during the one - year follow - up period. toxoplasma encephalitis seems to be associated with an impaired immunological response to art compared to patients with pneumocystis pneumonia. this regards mainly the first months after art - initiation and may be caused by the myelosuppressive side effects of anti - toxoplasmosis drugs. further investigations about this effect including direct biological influence of toxoplasmosis on immune restoration and drug interactions between art and anti - infective treatment are of great interest. the search for new drugs against toxoplasma gondii should be intensified as well. with respect to clinical management, guidelines regarding time of initiation and duration of anti - toxoplasmosis treatment should be critically reviewed, especially to avoid the " vicious circle " of decisions guided solely by cd4-cell count. aids : acquired immune deficiency syndrome ; art : antiretroviral therapy ; hpc : patients from countries of high hiv - prevalence ; m1 ; m2... : month 1 ; month 2... ; msm : men who have sex with men ; oi : opportunistic infection ; pcp : pneumocystis pneumonia ; q1 ; q2... : quarter 1 ; quarter 2... ; te : toxoplasmic encephalitis ; vl : viral load berlin : pd dr. k. arasth, s. kowol : auguste - viktoria - klinikum ; dr. f. bergmann, m. warncke : charit campus virchow ; bochum : prof. j. wasmuth : universittsklinikum bonn ; dsseldorf : dr. m. oette, c. blondin : universittsklinik dsseldorf ; essen : dr. g. ftkenheuer, t. kmmerle, d. gillor : universittsklinik kln ; mnchen : prof. c. fritzsche ; universittsklinik rostock cohort manager : a. kuehne, robert koch institute, berlin, germany the clinsurv study is primarily funded by the robert koch - institute and was partly funded by a grant from the german federal ministry of education and research (2003 - 2005), and the german federal ministry of health (1999). berlin : pd dr. k. arasth, s. kowol : auguste - viktoria - klinikum ; dr. f. bergmann, m. warncke : charit campus virchow ; bochum : prof. j. wasmuth : universittsklinikum bonn ; dsseldorf : dr. m. oette, c. blondin : universittsklinik dsseldorf ; essen : dr. g. ftkenheuer, t. kmmerle, d. gillor : universittsklinik kln ; mnchen : prof. c. fritzsche ; universittsklinik rostock cohort manager : a. kuehne, robert koch institute, berlin, germany the clinsurv study is primarily funded by the robert koch - institute and was partly funded by a grant from the german federal ministry of education and research (2003 - 2005), and the german federal ministry of health (1999). | objectivesthere is only little data on immune reconstitution in antiretroviral nave aids - patients with toxoplasmosis. the observation of several cases with reduced increase of cd4-cells upon start of antiretroviral treatment (art) prompted us to investigate the topic using the clinsurv cohort.methods17 german hiv treatment centers contribute to clinsurv, a multicentre observational cohort under the auspices of the robert koch institute. we retrospectively selected all antiretroviral - nave patients with toxoplasmic encephalitis (te) and -as comparator group -with pneumocystosis (pcp) between january 1999 and december 2005.resultsa total of 257 patients were included in the analysis, 61 with te and 196 with pcp. demographic baseline data showed differences with regard to gender, transmission group, and baseline cd4 + counts (60.9 vs. 44.7/l, p = 0.022). after art - initiation the increase in cd4 + lymphocytes was lower in the te - versus the pcp - group in the first, second and fourth three - month - period (74.4 vs. 120.3/l, p = 0.006 ; 96.6 vs. 136.2/l, p = 0.021 ; 156.5 vs. 211.5/l, p = 0.013). viral load (vl) was higher in the pcp - group at baseline (4.46 log10cop / ml vs. 5.00 log10cop / ml, p = 0.008), while virological success of art was equal.conclusionsour data show for the first time that the average cd4 + t - cell increase of patients with toxoplasmosis is impaired compared to pcp - patients. most clinicians would not be prepared to discontinue follow - up te - therapy unless cd4 + counts of 200/l are reached. explanation for our finding might be the myelosuppressive side effect of pyrimethamine, possible interactions of toxoplasmosis therapy with art, or an unknown direct biological influence of toxoplasmosis on immune restoration. |
the cardia study is a multicenter, longitudinal investigation of the evolution of ischemic heart disease risk starting in young adulthood (17). the study began in 19851986 with 5,115 black and white adults 1830 years of age from four metropolitan areas (birmingham, al ; chicago, il ; minneapolis, mn ; and oakland, ca). study participants were sampled to obtain roughly equal numbers of blacks (51.5%) and whites (48.5%), men (45.5%) and women (54.5%), 1824 years of age (44.9%) and 2530 years of age (55.1%), and with a high school education or less (39.7%) and with more than a high school education (60.3%). participants were contacted by telephone every year and examined in person at baseline and 2, 5, 7, 10, 15, 20, and 25 years after baseline. a majority of the group was examined at each of the follow - up examinations (91, 86, 81, 79, 74, 72, and 72% of survivors, respectively). at each clinical examination, participants were asked to present fasting in the morning. tobacco use, strenuous physical activity, and intake of caffeine, food, and alcohol were proscribed. the examinations followed standardized protocols harmonized over time and included measurements of blood pressure (bp), anthropometrics, and phlebotomy and structured questionnaires on sociodemographics, medical and family history, psychosocial characteristics, and diet, among others. the cardia study was approved by the institutional review board of each participating institution, and signed informed consent was obtained at each examination. during each clinic exam, blood was drawn from an antecubital vein, and after serum separation, aliquots were stored at 70c until shipped on dry ice to a central laboratory. procedures followed in the collection and storage of plasma samples, laboratory quality - control procedures, and methodology for analysis of plasma triglycerides, hdl cholesterol, ldl cholesterol, and total cholesterol are described elsewhere (18). serum glucose was measured at year 0 using the hexokinase ultraviolet method by american bio - science laboratories (van nuys, ca) and at subsequent examinations using hexokinase coupled to glucose-6-phosphate dehydrogenase by linco research (st. bp was measured three times at 1-min intervals. at the baseline through year 15 follow - up exams, bp was measured using the hawksley (lancing, sussex, u.k.) random - zero sphygmomanometer ; the first and fifth phase korotkoff sounds were recorded (17). at the year 20 and 25 exams, bp was measured with an automated sphygmomanometer (omron hem907xl oscillometer ; omron, schaumburg, il). the protocol specified the appropriate cuff size (small, medium, large, or extra - large) based on the upper arm circumference, which was measured by the bp technician at the midpoint between the acromion and the olecranon. omron values were recalibrated to corresponding random zero values based on a study of both measurement techniques in 903 participants at year 20, as estimated random zero systolic value = 3.74 + 0.96 omron systolic value, and estimated random zero diastolic value = 1.30 + 0.97 omron diastolic value (19). anthropometry (height, weight, and waist circumference) was measured at each exam. body weight was measured to the nearest 0.2 kg using a calibrated balance beam scale in participants wearing light clothing. height (without shoes) was measured to the nearest 0.5 cm using a vertical ruler and waist circumference to the nearest 0.5 cm at the minimal abdominal girth (20). diet was assessed at years 0, 7, and 20 by using an interviewer - administered cardia diet history questionnaire (21). interviewers asked open - ended questions about dietary consumption in the past month within 100 food categories that referenced 1,609 separate food items. additionally, visits per week to fast food restaurants were queried at each examination, and frequency of breakfast, lunch, dinner, and morning, afternoon, and evening snacks (days / week) was queried at years 7 and 20. an a priori dietary quality score based on overall dietary intake was included as a covariate (16). in brief, 46 food groups considered beneficial or adverse with respect to health effects were categorized by increasing consumption level with scores of 04 (for 20 food groups considered beneficial), 40 (for 13 food groups considered adverse), or 0 (for 13 food groups considered neutral). the a priori dietary quality score was the sum of category scores, with a theoretical maximum of 132. based on prior findings, it was assumed that a higher a priori dietary pattern score indicated better diet quality (2224). nutrient and energy estimates had larger variability among blacks than among whites (21,25). for other covariates, sex, race, date of birth, education, and cigarette smoking were ascertained by a structured interview or self - administered questionnaire at each examination. a physical activity score was derived from the cardia physical activity history, which is a simplified version of the minnesota leisure time physical activity questionnaire (26). obesity was defined as bmi 30 kg / m and abdominal obesity as waist circumference > 88 cm for women or > 102 cm for men. hypertension was defined as systolic bp 140 mmhg, diastolic bp 90 mmhg, or self - reported use of antihypertensive medication. the metabolic syndrome was defined using the national cholesterol education program (ncep) adult treatment panel (atp) iii criteria (27) as the presence of three or more of the following five conditions : 1) abdominal obesity, 2) fasting triglycerides 150 mg / dl, 3) hdl cholesterol 88 cm for women or > 102 cm for men. hypertension was defined as systolic bp 140 mmhg, diastolic bp 90 mmhg, or self - reported use of antihypertensive medication. the metabolic syndrome was defined using the national cholesterol education program (ncep) adult treatment panel (atp) iii criteria (27) as the presence of three or more of the following five conditions : 1) abdominal obesity, 2) fasting triglycerides 150 mg / dl, 3) hdl cholesterol < 40 mg / dl in men and < 50 mg / dl in women, 4) bp 130 mmhg systolic or 85 mmhg diastolic or use of antihypertensive medications, and 5) fasting glucose 100 mg / dl or use of diabetes medications. incidence of type 2 diabetes was defined as use of diabetes medication (assessed at every visit), a fasting blood glucose level of 6.99 mmol / l (126 mg / dl) (measured at years 1025), 2 h postchallenge glucose 11.1 mmol / l (200 mg / dl) (performed at the year 10, 20, and 25 exams), and/or an hba1c 6.5% (48 mmol / mol) (assessed at the year 20 and 25 visits). from the total sample of 5,115, we excluded 1,029 who did not participate in the year 7 clinical exam, a further 171 who did not participate in any clinical exam in years 1025, 60 with diabetes at year 7, 215 without dietary data or with reported energy intakes not in the range of 8008,000 kcal / day for men and 6006,000 kcal / day for women, and 42 missing other data (alcohol, smoking, or physical activity) for an analytic sample of 3,598. for analyses on outcomes other than type 2 diabetes, participants prevalent with the condition at year 7 were also excluded and total n is provided in tables. breakfast intake frequency categories were created that allowed for logical cut points with a sufficient number of subjects. baseline (year 7) characteristics were calculated across breakfast intake frequency categories reported at this exam. multivariable least squares adjusted means from general linear models (sas proc glm) were used to estimate weight gain in kilograms and increase in waist circumference in centimeters by breakfast intake frequency categories. the models adjust for age, study center, race, sex, education (years), cigarette smoking (current, former, or never), physical activity (units / week), alcohol consumption (ml / day), fast food restaurant use (visits / week), overall dietary quality score, frequency of lunch / dinner and morning / afternoon / evening snacks (days / week), total energy intake (kcal), and weight or waist circumference and height at year 7, respectively. all participants were free of diabetes at each time point in the analysis of weight and waist circumference changes. proportional hazards (cox) regression (sas proc phreg) was used to examine the association between breakfast intake frequency categories and incidence of metabolic conditions. time to event was calculated from the date of the baseline examination (year 7) to the date of the first follow - up examination meeting the criteria for the incident outcome (cases) or to the date of the last cardia examination for each participant without the incident outcome (censored). the main model included age (years), study center, race, sex, education (years), cigarette smoking (current, former, or never), physical activity (units / week), alcohol consumption (ml / day), fast food restaurant use (visits / week), dietary quality score, frequency of lunch / dinner and morning / afternoon / evening snacks (days / week), and total energy intake (kcal). depending on the outcome, either waist circumference (cm) or bmi (kg / m) from year 7 was included in a second model, and, for hypertension, a third model further adjusted for systolic bp at year 7 in analyses examining potential mediators. there was no evidence that proportional hazards assumptions were violated for any of the outcomes as indicated by the lack of significant interaction between the breakfast intake frequency variable and time in the models. tests for trend were performed by assigning the median value of intake frequency to the category and entering this as a continuous ordinal variable into the models. effect modification of the associations was considered by level of the dietary quality index, bmi, race, and sex. all analyses were conducted with sas statistical software version 9.2 (sas institute, cary, nc). based upon the year 7 data, 43.2% of participants reported infrequent breakfast intake (03 days / week), 21.7% reported eating breakfast frequently (46 days / week), and 35.1% of participants reported eating breakfast daily (7 days / week) (table 1). with higher levels of breakfast intake, a greater proportion of participants were white and female and were on average more educated, consumed less alcohol, did not currently smoke, were more physically active, had a lower bmi, visited fast food restaurants less frequently, and had a higher dietary quality score. participant characteristics according to breakfast frequency (days per week) : cardia year 7, 19921993 over 18 years of follow - up, there was a significant mean weight gain in all participants free of diabetes throughout the study ; yet, frequent (46 days / week) and daily breakfast consumers gained less weight relative to non- or infrequent breakfast consumers (supplementary fig. specifically, participants reporting daily breakfast intake gained 1.91 kg less than those reporting infrequent intake (03 days / week) (p = 0.001) over 18 years after full adjustment for demographic, lifestyle, dietary habits, and baseline weight., there was a stepwise decrease in crude incidence rate, and the incidence rate was nearly halved in daily breakfast consumers relative to those who were infrequent breakfast consumers (03 days / week) (table 2). these graded associations were evident in the main cox regression model adjusting for demographics, lifestyle covariates, and dietary habits. relative to infrequent intake of breakfast, frequent breakfast intake (46 days / week) and daily breakfast intake were each significantly associated with a decreased risk of abdominal obesity, obesity, metabolic syndrome, hypertension, and type 2 diabetes in a ranked manner. after adjustment for baseline measures of adiposity (waist circumference [cm ] or bmi [kg / m ]), the associations were attenuated but a significant inverse association persisted between daily breakfast intake and abdominal obesity, obesity, metabolic syndrome, and hypertension. hr and 95% ci of metabolic outcomes according to breakfast frequency : cardia years 725 (19921993 to 20102011) the estimates for incident type 2 diabetes were mediated upon adjustment for bmi in the whole - population hr and 95% ci for frequent breakfast intake (hr 0.82 [95% ci 0.631.07 ]) and daily intake (0.81 [0.631.05 ]). however, there was evidence that the results for type 2 diabetes differed in black women from those for the rest of the study sample (table 3). in black women, breakfast intake frequency was not associated with incident type 2 diabetes, whereas the results were consistent and strongly inversely associated in black men and white men and women even after adjustment for bmi. black women had the highest rate of incident diabetes in the cohort and greatest mean level of bmi in year 7 (29.0 kg / m) relative to the rest of the study population (black men, 27.0 kg / m ; white men, 26.0 kg / m ; white women, 24.9 kg / m). adjustment for hypertensive status and medication did not materially alter the results for incident type 2 diabetes. hr and 95% ci of type 2 diabetes according to breakfast frequency, stratified results : cardia years 725 (19921993 to 20102011) there was no evidence that the results varied for any of the other outcomes by race, sex, or bmi at baseline. there was no evidence that adjustment for family history of type 2 diabetes or hypertension materially altered any of the results. the frequency of lunch, dinner, or snacks was not associated with any of the outcomes. of note, we also examined the association between breakfast intake frequency and future dyslipidemia (low hdl cholesterol and elevated triglycerides per atp iii criteria). there was an inverse, but nonsignificant, association with greater breakfast intake (data not presented). we hypothesized that the association between breakfast intake frequency and metabolic risk may vary by the quality of the overall dietary pattern, i.e., any association may be limited to those with higher relative diet quality. however, we found no evidence in formal tests for interaction or stratified analyses that the relationship between breakfast intake frequency and metabolic risk was differential by overall dietary quality. we present results from the analysis with metabolic syndrome (table 4) as they are typical of findings for the outcomes examined. we ranked the dietary quality score into quartiles, with the lowest representing the poorest overall quality and the highest representing a theorized best overall dietary pattern. across quartiles of dietary quality, there was a stepwise decrease in incidence rate of metabolic syndrome with greater breakfast intake frequency. the highest incident rates of metabolic syndrome were observed in infrequent breakfast consumers (03 days / week) in the bottom half of overall dietary quality, whereas the lowest incident rates of metabolic syndrome were observed in the daily breakfast eaters in the top half of overall dietary quality. in the main stratified cox regression model (model 1), there was a graded inverse association with incident metabolic syndrome with more frequent breakfast intake across overall dietary quality ; however, the results were only suggestively significant in the lowest quartile of diet quality. hr and 95% ci of metabolic syndrome according to breakfast frequency by overall dietary quality : cardia years 725 (19921993 to 20102011) we also performed a sensitivity analysis with metabolic syndrome as the outcome exploring the statistical effect of adjustment for common breakfast foods in the study (timing of consumption was not asked). the whole grain breakfast cereal food group was the only breakfast - oriented food to materially alter the point estimates in model 2 with metabolic syndrome as the outcome (hr 0.86 [95% ci 0.721.02 ]) for daily breakfast relative to infrequent breakfast. the refined grain cereals, eggs, sausage / processed meats, fried potatoes, and donuts / pastries / cakes food groups did not materially alter the point estimates. of note, breakfast frequency at year 7 displayed an r = 0.46 (p < 0.0001) correlation with breakfast frequency at year 20. accounting for the year 20 breakfast data significantly depleted the analytic sample (4260% of sample depending on outcome) since any prospective examination between year 20 and 25 exams required data from year 7 and 20, no history of the respective metabolic condition at year 20, and attendance at the year 25 exam. in the sensitivity analyses accounting for the average breakfast intake over time in this subgroup (years 7 and 20), the results did not materially differ from the results presented using the year 7 data. in black and white young adult men and women, frequent (46 days / week) and daily (7 days / week) breakfast consumption was associated with a decreased risk of developing abdominal obesity, obesity, metabolic syndrome, hypertension, and type 2 diabetes over 18 years of follow - up relative to their peers with infrequent breakfast consumption (03 days / week). these findings remained significant for daily breakfast intake for all outcomes except type 2 diabetes after accounting for baseline measures of adiposity. however, the inverse relationship between greater breakfast frequency and type 2 diabetes risk remained independent of bmi in black men and white men and women, whereas in black women, there was no association between breakfast intake and type 2 diabetes incidence. of note, counter to our hypothesis, the results were not explained by the overall quality of the dietary pattern. prospective research examining a range of breakfast intake frequencies with metabolic outcomes is limited. in the only other study to examine a range of breakfast intakes, there was a gradient of bmi change in adolescents across categories of breakfast frequency, with never eaters experiencing the greatest increase and daily eaters experiencing the smallest increase (8). in the health professionals study, breakfast consumers (yes vs. no) had a lower risk of a 5-kg weight gain over 10 years (9). in a tangentially related study, greater intake frequency of both refined and whole grain ready - to - eat cereals was associated in a dose - dependent manner with lower mean weight gain and lower risk of becoming overweight (bmi 25 kg / m) (10). in a similar examination of physicians health study data, there was an inverse association between greater intake of cereal and risk of developing hypertension, although with greater limits in the interpretation due to the dietary assessment (12). in a study of australian children who were followed up as young adults, those who reported yes at both childhood and young adulthood at a dichotomous assessment of breakfast consumption (yes vs. no) had lower levels of clinical cardiometabolic risk factors relative to those who skipped at different life - course points (14). two different studies have examined aspects related to breakfast in relation to type 2 diabetes. in the health professionals study, men who did not eat breakfast (yes vs. no) were at an increased risk of developing type 2 diabetes, and those who had a high western dietary pattern score and did not eat breakfast experienced an even greater risk of incident type 2 diabetes (13). the physicians health study also found that more frequent intake of ready - to - eat cereal, especially whole grain cereal, was inversely associated with risk of incident type 2 diabetes (11). two other studies have linked aspects of breakfast intake with reduced risk of mortality during their follow - up periods (28,29). in summary, our study and these other studies all suggest that breakfast intake, or frequent consumption of foods associated with breakfast intake, is important for metabolic health. cardia provides a unique and thorough look at the topic with data on the spectrum of possible breakfast intake frequencies as a dietary behavior. this ability to examine the range of breakfast intake uniquely distinguishes it from previous research on the topic and better aligns the data with real - world behavior (8,15,16). furthermore, the quality of the overall dietary pattern is important for health (16), but this did not explain our results, suggesting that the act of breaking the fast may have important metabolic health implications beyond the quality of the overall dietary pattern. there are a number of plausible mechanisms whereby eating breakfast may improve acute and long - term factors salient for metabolic risk. as summarized by timlin and pereira (6), a spectrum of research provides evidence that the act of eating breakfast, as well as the content, plays important roles in factors related to appetite and hormone, glucose, insulin, and lipid metabolism. indeed, the time of day and frequency of eating, as well as content, have important independent effects on energy intake, dietary content, and hormonal response that are central to energy balance and thus adiposity (30,31). greater breakfast intake frequency was strongly and inversely associated with long - term risk of obesity in this study. this appears to be a mechanism by which breakfast intake may reduce risk for metabolic syndrome, type 2 diabetes, and hypertension. since these estimates were not completely mediated by adiposity in our statistical models, this suggests that breakfast intake impacts other avenues, likely hormonal glucose, insulin, and lipid metabolism factors central to these conditions (32). a few studies with experimental designs examined the effects of eating breakfast or a larger portion of daily energy intake in the morning on weight loss with some suggestion of benefit, but with mixed results possibly due to study design and sample size (33,34). other small experimental studies have found that omitting breakfast and the composition of breakfast have effects on appetite and metabolic parameters that could impact long - term metabolic risk (3537). further trials have demonstrated that the content of breakfast is likely important for lower metabolic risk as breakfast meals emphasizing low - glycemic whole grains had beneficial effects on appetite and metabolic parameters throughout the day (36,3840). the sensitivity analysis we performed examining different breakfast - type foods aligns with this point. overall, the small base of prospective and experimental research on breakfast intake suggests that it may have an independent beneficial role in metabolic health. prospective population studies examining breakfast habits and larger and longer experimental studies examining specific mechanisms addressing both the act of eating breakfast and the content would provide a more definitive level of evidence on breakfast intake and metabolic health. they would also inform the level of emphasis that should be given to this dietary habit in relevant dietary interventions and overall dietary recommendations. our study has a number of strengths : long - term, prospective study design, with high rates of follow - up ; standardized, valid, and reliable measurements of dietary practices ; extensive clinical measures and data on covariates with which to explore confounders and mediators of the associations under investigation ; and the demographics of the cohort, young adult black and white men and women from four u.s. metropolitan areas who have been examined during a period of life when substantial weight gain occurs and metabolic complications develop. limitations include some level of measurement error with the dietary assessment, although this would most likely result in nondifferential misclassification with respect to any of the outcomes and likely underestimation of risk. although a working scientific definition of breakfast has been proposed in the time since cardia began (6), there was no explicit definition of what constituted a breakfast meal in the cardia study. the self - report of other lifestyle - related data may also result in some misclassification and residual confounding in our models. because of this, it is possible that the association between daily breakfast intake and significantly reduced metabolic risk is a proxy for an overall better diet and lifestyle. in conclusion, young adults who reported eating breakfast everyday had a significantly lower risk of an array of metabolic outcomes relative to their peers who infrequently or never ate breakfast, independent of adiposity and the overall quality of the dietary pattern. our study and other burgeoning evidence (814) suggest that the science is catching up to the early nutritional beliefs related to the topic and eating a daily breakfast meal is a dietary habit that may be highly relevant for metabolic health. | objectivethe relation of breakfast intake frequency to metabolic health is not well studied. the aim of this study was to examine breakfast intake frequency with incidence of metabolic conditions.research design and methodswe performed an analysis of 3,598 participants from the community - based coronary artery risk development in young adults (cardia) study who were free of diabetes in the year 7 examination when breakfast and dietary habits were assessed (19921993) and participated in at least one of the five subsequent follow - up examinations over 18 years.resultsrelative to those with infrequent breakfast consumption (03 days / week), participants who reported eating breakfast daily gained 1.9 kg less weight over 18 years (p = 0.001). in a cox regression analysis, there was a stepwise decrease in risk across conditions in frequent breakfast consumers (46 days / week) and daily consumers. the results for incidence of abdominal obesity, obesity, metabolic syndrome, and hypertension remained significant after adjustment for baseline measures of adiposity (waist circumference or bmi) in daily breakfast consumers. hazard ratios (hrs) and 95% cis for daily breakfast consumption were as follows : abdominal obesity hr 0.78 (95% ci 0.660.91), obesity 0.80 (0.670.96), metabolic syndrome 0.82 (0.690.98), and hypertension 0.84 (0.720.99). for type 2 diabetes, the corresponding estimate was 0.81 (0.631.05), with a significant stepwise inverse association in black men and white men and women but no association in black women. there was no evidence of differential results for high versus low overall dietary quality.conclusionsdaily breakfast intake is strongly associated with reduced risk of a spectrum of metabolic conditions. |
qt was received as gifted by torrent pharmaceuticals pvt. ltd., polyox n 10, polyox n 80, polyox n 750 and polyox n 205 were gifted by dow chemicals pvt preliminary trials were carried out for selection of appropriate grades of polyox from different grades mentioned above. concentration of polymer and plasticizers were optimized by central composite design. in this design 2 factors the amount of polyox n750 (x1) and peg 400 (x2) were selected as independent variables. the tensile strength, folding endurance, % drug released at 10 min (y10) and disintegration time were selected as dependent variables. preliminary trials were carried out for selection of appropriate grades of polyox from different grades mentioned above. concentration of polymer and plasticizers were optimized by central composite design. in this design 2 factors the amount of polyox n750 (x1) and peg 400 (x2) were selected as independent variables. the tensile strength, folding endurance, % drug released at 10 min (y10) and disintegration time were selected as dependent variables. different grades of polyox were used for film formation like n10, n80, n750 and n205. initially, preliminary trials were carried out to select ideal grade of polymer used for film formation and then used for optimization of other parameters of film. different mentioned grades were tried between 1 - 4% concentrations. from the result, it was observed that by increasing the concentration of polymer up to 2%, thickness and strength of film was improved. but by increasing concentration more than 2%, folding endurance of film was improved but increase in disintegration time more than limit. thus, 2% concentration of polymer was used for further optimization of plasticiser and sweeteners. plasticizer tried were glycerin, peg 400, and propylene glycol in 15% concentration each. glycerin and propylene glycol showed more sticky film which was unable to detach from surface. polyox n750 was selected for further optimization of film property due to its excellent film forming nature with optimum viscosity for rapid dissolving film. comparison of % elongation of design batches comparison of film thickness of design batches optimization of concentration of polyox n750 and % of peg as plasticisers was optimized systematically using with central composite design (ccd). it was observed that disintegration time of all the batches ranges between 6 - 30 sec, tensile strength between 0.106 0.760 kg / cm, folding endurance between 10 - 89 and drug release profile with in 10 min 80%-99%. all the batches showed more than 80% drug release profile in initial 10 min. from all evaluation parameter, r10 batch with 2% polyox 750 and 15% of peg 400 was considered as promising batch with all satisfactory parameters. for validation of optimum formulation, check point r14 was prepared and evaluated for all the response. observed value was found close to the predicted value, which indicated good correlation of results. optimized film was analyzed by dsc spectra and compared with dsc spectra of pure drug. spectra showed presence of drug peak at same energy of enthalpy as that of pure qt. formulation was stored at 65% relative humidity and 37c temperature in the humidity oven. after 3 months film some predictable changes were observed in film property like decrease in disintegration time and more softness of film due to higher amount of moisture. film texture was evaluated after 3 months of storage which indicates increase in stickiness of film at higher relative humidity. the results of central composite design revealed that the entire factor significantly influences the dependent variable. thus, it can be concluded that by adopting a systematic formulation approaches, an optimum point can be reached in the shortest time with minimum effort. thus, developed film can be useful for curing the emergency condition like schizophrenia which gives rapid relief within short time. stability study data shows need of proper storage condition for film to protect from effect of moisture. | quick dissolving film prepared by various grades of polyox like polyox n10, n80, n750 and n205. polyox having excellent film forming capacity with rapid hydration power which leads to rapid disintegration of film upon contact with saliva. film is optimized for concentration of polymer and plasticizer using ccd design. the tensile strength, folding endurance, % drug released at 10 min (y10) and disintegration time were selected as dependent variables. the data revealed that 2% of polyox n 750 and 15% of peg 400 showed excellent film forming property with rapid drug release profile. |
duplication of the alimentary tract is an important surgical condition, which includes a wide variety of mass lesions. we encountered a patient who presented with perforation of the duplication, which was associated with malrotation with midgut volvulus. being an extremely uncommon surgical emergency, it is being presented with a brief review of the relevant literature. a 4-year - old male child was referred to us for complaint of pain in abdomen. however, there was occasional history of abdominal pain, which was relieved by medication. on examination, his abdomen was distended, but it was non - tender. a computerized tomography (ct) scan of abdomen was advised for confirmation of the diagnosis. on next day, just after ct abdomen, the patient suddenly developed severe abdominal pain. after initial stabilization, the patient was explored under general anesthesia. on exploration, we noticed malrotation of the gut, which was associated with two turns of midgut volvulus. ladd 's bands were also present. the peritoneal cavity was grossly contaminated with fecal fluid. the perforation was at the mesenteric side, and it was associated with a soft mesenteric mass communicating with the normal bowel. the perforation was just at the junction of the mesenteric mass and the normal bowel [figure 1 ]. the other thumb forceps is in the perforated duplication after performing the ladd 's procedure, attention was placed towards the perforation. on attempting to resect the mesenteric mass, we noticed two lumens in the bowel distal to the perforation site and single lumen proximal to that [figures 2 and 3 ]. when an attempt to ascertain the length of the duplication was made by inserting two ryle 's tube through the lumens, it was reaching up to ileocecal region. as the general condition of the patient was poor, complete resection of the bowel was not done, and a double barrel (triple barrel, to be more precise) was fashioned. (a) duplication cyst, (b) junction of duplication and normal bowel, and it was the site of perforation, (c) normal ileum, (d) duplicated ileum reaching up to cecum, and (e) cecum and probable site of duplication termination in the postoperative period, there was wound infection with superficial wound dehiscence. the patient was discharged after 3 weeks with proper follow - up advise. during the follow - up these abnormalities include developmental obstructive defects of the small intestine, anomalies of rotation and fixation, intestinal duplications, etc. duplications of the alimentary tract are rare congenital malformations and may occur anywhere in the intestinal tract. the initial suspicion, on the basis of usg, was of some cystic mass lesion compressing the upper small bowel. the ct plates, reviewed later on, also showed twisting of mesenteric vessels suggestive of malrotation. probably the perforation of the duplication was not spontaneous ; it may be because of the volvulus and resultant ischemia of the wall. as malrotation with midgut volvulus is always a surgical emergency, and perforated duplication is also a surgical emergency, a combination of the two entities is definitely a surgical emergency, which needs immediate intervention. the ideal treatment would have been a ladd 's procedure, along with resection of the complete duplication. this was, however, not possible due to the poor general condition of the patient and large length of the duplication, which may had led to extensive resection of the bowel. the association of duplication of small bowel and malrotation, though described in the literature, is a rare one.. to conclude, this being one of a very rare combination of two pediatric surgical emergencies ; needs proper surgical and postoperative management. the exact preoperative diagnosis may be difficult, but a high degree of suspicion is warranted. | duplication of the alimentary tract is an important surgical condition. it may occur anywhere in the gastrointestinal tract. an important complication of this entity is perforation of the normal or abnormal gut. malrotation with midgut volvulus can be a surgical emergency. we present a patient, who presented as malrotation with midgut volvulus associated with perforated ileal duplication. the patient was successfully managed. |
the nmr structure of budding yeast chaperone chz1 complexed with histones h2a.z - h2b has been determined. chz1 forms a long irregular chain capped by two short -helices, and uses both positively and negatively charged residues to stabilize the histone dimer. a molecular model that docks chz1 onto the nucleosome has implications for its potential functions. |
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historically the problem of visual stability has been simplified to address only a fixed visual world with a fixed head. until a few decades ago the dominant theory evoked a signal emanating from motor areas of the brain to inform the visual system about eye movements. at the time of an eye movement this signal would be subtracted from the resulting retinal image shift, achieving space constancy. because the idea requires that visual centers receive a copy of the neural efference to the eye muscles, von holst and mittelstaedt (1950) named it efference copy. formal descriptions originated with bell (1823) and purkinje (1825), who described it independently. helmholtz (1866) expanded the empirical base for efference copy with observations of neurological patients who had eye muscle damage. another extraretinal signal, proprioception from the eye muscles, was later proposed as a source of information that could contribute to space constancy (sherrington 1918). not all theorists have accepted this position ; j j gibson asserted that motion of the entire visual field would always result in a perception of self - motion. asking whether the world should appear to move when the visual field sweeps by, he answered, why should it move ? the retina is proprioceptive (gibson 1966 p 256). simply pressing on one eye while closing the other disproves this assertion, for then the whole world appears to move. von holst and mittelstaedt (1950) inverted the head of the blowfly eristalis, holding it with a piece of wax. the fly would circle either clockwise or counterclockwise at random. in darkness, though, the fly 's locomotion seemed normal. the conclusion was that the fly compared the output of its locomotor system with the retinal flow field (since the fly 's eye is fixed to its head, and in the experiment is also fixed to the body, the locomotor system is also the oculomotor system). the efferenzkopie would subtract from the retinal signal to stabilize locomotion (figure 1). inverting the head converted the negative feedback to positive feedback correct in the same direction, resulting in a further deviation in the same direction. independently, sperry (1950) made similar observations in a fish with a surgically inverted eye, naming the signal corollary discharge. use of efference copy to stabilize a perceived visual world, redrawn to american engineering conventions. efference copy is subtracted () from the visual input, afference (+), at a comparator to present a stable representation to the brain. first, efference copy informs the brain of where the eyes should be rather than where they are. as such it can not be exact it should drift with time, and inaccuracies can not be corrected. yet perceptual space constancy is perfect the world does not appear to jump in the slightest when the eyes move. further, quantitative measures of saccadic suppression of displacement showed that, at the optimal timing of image displacement and saccade, the perceptual threshold was nearly 1/3 as large as the saccade (bridgeman 1975). any orientation mechanism with an error this large had no idea where the world was, and could support neither space constancy nor visual - motor calibration. experiments exploiting alternating eye movements, either from rapidly repeated eye presses (ilg 1989) or from rapidly alternating saccadic eye movements (nagle 1980 ; grsser 1987), demonstrated that both motor and sensory compensation were effective at low temporal frequencies but failed at higher frequencies. thus any efference - copy - based system fails at rates well within the temporal range of normal perception. the eyepress has been misunderstood since purkinje 's 1825 assumption that it elicits a passive eye movement ; the real situation is exactly the reverse. the reader can easily verify this pick a fixation target, then close one eye while slowly pressing on the other through the lid. you will be able to hold your gaze on your fixation target while the visual world, target and all, appears to move. thus the retina is not moving with respect to the visual world. rather than revealing the effect of passive eye movement, the eyepress shows the effect of active compensation for oculomotor disturbance. efference copy alone can drive motion perception (bridgeman and stark 1991). pressing on the viewing eye changes efference without changing gaze position, but pressing on the covered eye the covered eye when pressed should rotate under the eyelid, because the press does not result in any corrective signal from visual error feedback. the situation in pressing the viewing eye is now more complicated, because efference copy and proprioception work in opposite directions. proprioception will come from the deviated, covered eye, and altered efference copy will be driven by the active compensation for the press of the viewing eye (suggested by wenshun li of columbia university). presses on the viewing or the covered eye could be used to recover the internal proprioception and efference copy signals by algebraic reconstruction of the measured signals (bridgeman and stark 1991). the resulting gains were 0.61 for efference copy and 0.26 for proprioception ; even with perfect summation of the gains at 0.87, the brain would underestimate how far the eye really moved. in fact it accounts for previously unexplained data on the perceived deviation of an eccentric target from the midline ; targets are perceived as more eccentric if their position is judged in peripheral vision, with the eyes straight ahead, than if they are fixated (morgan 1978). the gain from morgan s data is 0.13, precisely the efference copy, proprioception, and illusion gains sum to 1.00, closing the circle on the signals used to register gaze position and consequent perceptions. two centuries of work had led to the conclusion that efference copy dominates ; we can now see that the reason for the domination is that its gain is about 2.4 times greater than the proprioceptive gain. thus efference copy explains a wide range of results and clinical observations better than proprioception. efference copy clearly can not support space constancy, but for years no alternative was available. o'regan (1992) asserted that there need be no memory for the content of previous fixations, because the information remains in the world and can be reacquired whenever an observer wants it. we knew by then that no brain area contained a panoramic, high - acuity representation that corresponds to our spatially stable perception. calibration solution : spatiotopic positions are calculated anew from proprioception, efference copy, and retinal sources for each fixation. previous fixation positions are not taken into account ; the world appears to be in the same place because nothing tells the brain that it is not. an elaboration of this idea was motivated by data showing that a saccadic target object that is present continuously appears to be stabilized, while objects that are interrupted near the time of a saccade appear to jump, even if it is the continuous target that really jumps (deubel 2004). to explain this, deubel conclude that, before a saccade is executed, attention shifts to a reference object whose location and attributes are stored in a transsaccadic memory. information from the previous fixation is discarded or ignored, and localization proceeds using currently available information. other objects are then localized relative to the reference object. only if the object is not found. evidence for this position comes from a number of sources, including change blindness, the difficulty of identifying changes in naturalistic scenes if they are masked by a brief blank (simons 1996 ; rensink 1997). the importance of change blindness is that inattention to previous images prevents their interfering with present perception. little is carried over from one fixation to the next ; we do not build a visual world by pasting together samples calibrated with efference copy, but simply perceive what is currently available, plus a gist and a few previously attended objects. the stable, rich visual world of our perception is more promise than physiological reality. | space constancy, the appearance of a stable visual world despite shifts of all visual input with each eye movement, has been explained historically with a compensatory signal (efference copy or corollary discharge) that subtracts the eye movement signal from the retinal image shift accompanying each eye movement. quantitative measures have shown the signal to be too small and too slow to mediate space constancy unaided. newer theories discard the compensation idea, instead calibrating vision to each saccadic target. |
endovascular embolization has become a method of choice for the treatment of intracranial aneurysms in many centers. however, an important disadvantage of aneurysm coiling is the observed significant rate of recanalization that occurs on average in 20% of patients. therefore, follow - up imaging of coiled aneurysms is recommended to prevent aneurysm recurrence and possible subsequent subarachnoid hemorrhage [57 ]. the role of intra - arterial digital subtraction angiography (dsa) as a standard follow - up method for embolized aneurysms has been questioned because of its invasiveness, need for hospitalization and relatively high cost. instead, magnetic resonance angiography (mra) has been proposed for this purpose as being less invasive and presenting very good accuracy in detecting residual flow in aneurysms [810 ]. the question of whether time - of - flight mra (tof - mra) or contrast - enhanced mra (ce - mra) is a better method for aneurysm follow - up remains unresolved. despite a higher signal intensity and a higher signal - to - noise ratio of ce - mra, both techniques present similar specificity and sensitivity in detecting residual flow in aneurysms. these drawbacks may be overcome by using time - resolved ce - mra, which enables imaging of cerebral vessels in several consecutive phases of contrast medium inflow. this study was a prospective comparison of the diagnostic value of tof - mra and time - resolved ce - mra at follow - up of embolized intracranial aneurysms regarding the determination of aneurysm occlusion. the study was approved by the university institutional review board and was performed in accordance with the declaration of helsinki. the study was based on a population of patients that participated in a prospective single - center study comparing the diagnostic value of dsa and mra in the follow - up of ruptured intracranial aneurysms (serafin z.. patients treated for subarachnoid hemorrhage due to aneurysm rupture, who presented for the first follow - up imaging at 3 months after the procedure, were included in the study. the exclusion criteria were : (a) age under 18 years ; (b) contraindications to mr imaging, including severe claustrophobia, ferromagnetic foreign bodies or electronic implants ; (c) the presence of neurosurgical clips ; and (d) estimated glomerular filtration rate (egfr) < 60 ml / min/1.73 m. embolizations were performed using platinum coils (gdc detachable coils, boston scientific, natick, usa ; axium and nexus, ev3 corporate, plymouth, usa ; microplex, microvention, inc., tustin, usa) and hydrogel coils (hydrocoil and hydrosoft, microvention, inc., tustin, usa). in 8 patients with broad - neck aneurysms, intracranial stents (neuroform3, boston scientific, natick, usa) were implanted prior to the coiling to achieve a better packing density and to prevent coil prolapse to the parent artery. after the embolization, the baseline status of the aneurysm was documented by dsa, including both 2-dimensional (2d) and 3-dimensional (3d) acquisitions. follow - up dsa was performed using a monoplane angiographic unit (axiom artis dta, siemens medical systems, erlangen, germany) by means of transfemoral catheterization. the examination included 4-vessel 2-d dsa and 3-d dsa of an artery with an embolized aneurysm. the contrast agent (iopromide, ultravist 300 mg - i / ml, bayer schering pharma ag, berlin, germany) was administered with a power injector through a 5-f catheter. images were analyzed on a dedicated workstation (syngo xvp va72b, siemens ag, berlin, germany) using inspace 3-d software. mr angiography was performed with a 1.5 t signa hdx unit, using an 8-channel hd brain coil (ge medical systems, waukesha, wi, usa) within 24 hours after dsa. the examination consisted of 2 sequences : tof - mra and time - resolved imaging of contrast kinetics (tricks). tof - mra was performed with a 3-d tof asset multislab technique in an axial plane (te 2.7 ms, tr 30 ms, flip angle 20, bandwidth 31.25 khz, section thickness 1.2 mm, matrix 320224). tricks acquisition consisted of 6 3-d phases in a coronal plane (te 1.5 ms, tr 3.5 ms, flip angle 25, bandwidth 83.33 khz, section thickness 2.2 mm, matrix 288192, temporal resolution 3 s). contrast medium (gadobenate dimeglumine, gd - bopta, multihance, 0.5 mmol / ml, bracco imaging deutschland gmbh, konstanz, germany) was administered by a power injection in a dose of 0.1 mmol / kg b.w. at 2 the final analysis was based on a phase that presented optimal delineation of arteries without significant contamination by venous enhancement (figure 1). angiograms were evaluated with advantage workstation 4.4 and volume share 8.4.3 software (ge medical systems, waukesha, wi, usa). the analysis included non - reconstructed images, as well as mpr, mip and vr reconstructions. the examinations were independently assessed by 2 interventional neuroradiologists (z.s, p.s.) with 10 years of experience in the field. the observers evaluated blinded data, and were unaware of the other imaging results of the patient. images were evaluated for the detection of residual flow in the aneurysm, quantification of the flow (ie, classification of the degree of aneurysm occlusion (class 13 according to roy.), and possibility of retreatment. the reference result was established retrospectively when results of index tests were set in all the study participants. the reference test was dsa, which constituted a simultaneous analysis of 2-d dsa images, 3-d dsa vr reconstructions, and source rotational dsa images. the quality of visualization was graded using a subjective semiquantitative scoring method that was proposed by gibbs.. the tof - mra and tricks examinations were evaluated for overall quality of parent artery delineation, distal vessel identification, vascular signal intensity, and motion artifacts. each examination was given a score on a 5-point scale : 5 signified excellent quality ; 4, more than adequate quality for diagnosis ; 3, adequate quality for diagnosis ; 2, less than adequate quality for diagnosis ; and 1, non - diagnostic. the wilcoxon signed - rank test was used to determine any statistically significant difference in image quality. the quantitative assessment of image quality was based on calculation of contrast - to - noise ratio (cnr) and signal - to - noise ratio (snr). arterial signal intensity (sia) of the mid - segments of basilar arteries was measured on non - reconstructed images in regions of interest (roi) of 23 mm, depending of the artery diameter. background signal intensity (sib) was measured in the brain stem in rois of 20 mm on average. the image noise was measured as the sd of air signal intensity (sdn) outside the skull in rois of 20 mm on average. snr and cnr for each examination were calculated as follows : snr = sia / sdn ; cnr=(siasib)/sdn. test characteristics of tof - mra and tricks vs. dsa as a reference were calculated with corresponding 95% ci and expressed the ability of index tests to properly detect residual flow in the aneurysm. the test characteristics included sensitivity, specificity, positive predictive value (ppv), negative predictive value (npv), positive likelihood ratio (lr+), negative likelihood ratio (lr), and diagnostic accuracy. the areas under the receiver operating characteristic curves (aucs) with their 95% cis were also calculated. significance of the auc values and significance of differences between them was tested with the z - test. the ability of tof - mra and tricks to properly classify the degree of aneurysm occlusion (class 13) was assessed with concordance correlation coefficient (ccc) with its 95% ci and weighted cohen s kappa (). intraobserver agreement and interobserver agreement were measured with cohen s with its 95% ci. a p - value of < 0.05 was considered significant. statistical analyses were performed using medcalc 11.6.0 (medcalc software, mariakerke, belgium) and statistica 9 (statsoft inc., tulsa, usa). the study was approved by the university institutional review board and was performed in accordance with the declaration of helsinki. the study was based on a population of patients that participated in a prospective single - center study comparing the diagnostic value of dsa and mra in the follow - up of ruptured intracranial aneurysms (serafin z.. patients treated for subarachnoid hemorrhage due to aneurysm rupture, who presented for the first follow - up imaging at 3 months after the procedure, were included in the study. the exclusion criteria were : (a) age under 18 years ; (b) contraindications to mr imaging, including severe claustrophobia, ferromagnetic foreign bodies or electronic implants ; (c) the presence of neurosurgical clips ; and (d) estimated glomerular filtration rate (egfr) < 60 ml / min/1.73 m. embolizations were performed using platinum coils (gdc detachable coils, boston scientific, natick, usa ; axium and nexus, ev3 corporate, plymouth, usa ; microplex, microvention, inc., tustin, usa) and hydrogel coils (hydrocoil and hydrosoft, microvention, inc., tustin, usa). in 8 patients with broad - neck aneurysms, intracranial stents (neuroform3, boston scientific, natick, usa) were implanted prior to the coiling to achieve a better packing density and to prevent coil prolapse to the parent artery. after the embolization, the baseline status of the aneurysm was documented by dsa, including both 2-dimensional (2d) and 3-dimensional (3d) acquisitions. follow - up dsa was performed using a monoplane angiographic unit (axiom artis dta, siemens medical systems, erlangen, germany) by means of transfemoral catheterization. the examination included 4-vessel 2-d dsa and 3-d dsa of an artery with an embolized aneurysm. the contrast agent (iopromide, ultravist 300 mg - i / ml, bayer schering pharma ag, berlin, germany) was administered with a power injector through a 5-f catheter. images were analyzed on a dedicated workstation (syngo xvp va72b, siemens ag, berlin, germany) using inspace 3-d software. mr angiography was performed with a 1.5 t signa hdx unit, using an 8-channel hd brain coil (ge medical systems, waukesha, wi, usa) within 24 hours after dsa. the examination consisted of 2 sequences : tof - mra and time - resolved imaging of contrast kinetics (tricks). tof - mra was performed with a 3-d tof asset multislab technique in an axial plane (te 2.7 ms, tr 30 ms, flip angle 20, bandwidth 31.25 khz, section thickness 1.2 mm, matrix 320224). tricks acquisition consisted of 6 3-d phases in a coronal plane (te 1.5 ms, tr 3.5 ms, flip angle 25, bandwidth 83.33 khz, section thickness 2.2 mm, matrix 288192, temporal resolution 3 s). contrast medium (gadobenate dimeglumine, gd - bopta, multihance, 0.5 mmol / ml, bracco imaging deutschland gmbh, konstanz, germany) was administered by a power injection in a dose of 0.1 mmol / kg b.w. at 2 the final analysis was based on a phase that presented optimal delineation of arteries without significant contamination by venous enhancement (figure 1). angiograms were evaluated with advantage workstation 4.4 and volume share 8.4.3 software (ge medical systems, waukesha, wi, usa). the analysis included non - reconstructed images, as well as mpr, mip and vr reconstructions. the examinations were independently assessed by 2 interventional neuroradiologists (z.s, p.s.) with 10 years of experience in the field. the observers evaluated blinded data, and were unaware of the other imaging results of the patient. images were evaluated for the detection of residual flow in the aneurysm, quantification of the flow (ie, classification of the degree of aneurysm occlusion (class 13 according to roy.), and possibility of retreatment. the reference result was established retrospectively when results of index tests were set in all the study participants. the reference test was dsa, which constituted a simultaneous analysis of 2-d dsa images, 3-d dsa vr reconstructions, and source rotational dsa images. parametric variables were expressed as mean values standard deviation (sd). the quality of visualization was graded using a subjective semiquantitative scoring method that was proposed by gibbs.. the tof - mra and tricks examinations were evaluated for overall quality of parent artery delineation, distal vessel identification, vascular signal intensity, and motion artifacts. each examination was given a score on a 5-point scale : 5 signified excellent quality ; 4, more than adequate quality for diagnosis ; 3, adequate quality for diagnosis ; 2, less than adequate quality for diagnosis ; and 1, non - diagnostic. the wilcoxon signed - rank test was used to determine any statistically significant difference in image quality. the quantitative assessment of image quality was based on calculation of contrast - to - noise ratio (cnr) and signal - to - noise ratio (snr). arterial signal intensity (sia) of the mid - segments of basilar arteries was measured on non - reconstructed images in regions of interest (roi) of 23 mm, depending of the artery diameter. background signal intensity (sib) was measured in the brain stem in rois of 20 mm on average. the image noise was measured as the sd of air signal intensity (sdn) outside the skull in rois of 20 mm on average. snr and cnr for each examination were calculated as follows : snr = sia / sdn ; cnr=(siasib)/sdn. test characteristics of tof - mra and tricks vs. dsa as a reference were calculated with corresponding 95% ci and expressed the ability of index tests to properly detect residual flow in the aneurysm. the test characteristics included sensitivity, specificity, positive predictive value (ppv), negative predictive value (npv), positive likelihood ratio (lr+), negative likelihood ratio (lr), and diagnostic accuracy. the areas under the receiver operating characteristic curves (aucs) with their 95% cis were also calculated. significance of the auc values and significance of differences between them was tested with the z - test. the ability of tof - mra and tricks to properly classify the degree of aneurysm occlusion (class 13) was assessed with concordance correlation coefficient (ccc) with its 95% ci and weighted cohen s kappa (). intraobserver agreement and interobserver agreement were measured with cohen s with its 95% ci. a p - value of < 0.05 was considered significant. statistical analyses were performed using medcalc 11.6.0 (medcalc software, mariakerke, belgium) and statistica 9 (statsoft inc., between november 2009 and march 2011, 74 patients with 74 aneurysms were included in this prospective study. thus, 72 patients (mean age 51.512.4 years), including 24 men and 48 women, were finally analyzed (table 1). there were no adverse reactions to contrast media during follow - up and there were no adverse events specifically related to dsa. the reference test revealed residual flow in 26 aneurysms (36.1%) (figure 2). the flow area was classified as class 2 (residual neck) in 8 cases (11.1%) and as class 3 (residual aneurysm) in 18 cases (25.0%). the mean quality score for tof - mra and tricks images was 4.080.64 and 3.880.67, respectively (p<0.03). on the other hand, both snr and cnr of tricks images were significantly higher than those of tof - mra 140.545.8 and 84.628.8 compared to 200.2146.3 and 182.0124.3, respectively (p<0.002). the tof - mra correctly diagnosed complete occlusion in 42 patients and residual flow in 22 patients, while 4 diagnoses were false - positive and 4 were false - negative (figure 3). however, in all cases treated with stent - assisted coiling, the signal intensity was slightly decreased within the stent lumen. the decrease of the signal intensity was less pronounced on tricks images than on tof - mra images and did not influence the evaluation of aneurysms. detection of the residual flow in tricks was true - positive in 23 cases, false - positive in 4 cases, false - negative in 3 cases, and true - negative in 42 patients. the quantification of the occlusion status of an aneurysm was more accurate with tricks (=0.83 ; ccc=0.86 ; 95% ci : 0.790.91) than with tof - mra (=0.76 ; ccc=0.80 ; 95% ci : 0.700.87), while auc values were not significantly different between the 2 methods (0.90, 95% ci : 0.810.96 and 0.88, 95% ci : 0.780.94, respectively). both tof - mra and tricks presented good or very good reproducibility for detecting the residual flow. intraobserver agreement was 0.86 (95% ci : 0.740.98) for tof - mra and 0.89 (95% ci : 0.780.99) for tricks. interobserver agreement was 0.74 (95% ci : 0.590.90) for tof - mra and 0.80 (95% ci : 0.670.94) for tricks. despite the fact that for many years dsa has been a standard diagnostic method for follow - up of embolized aneurysms, mr examination has become an accepted comprehensive alternative to invasive imaging, especially in outpatient practice. however, the most advantageous mra technique for follow - up remains the subject of debate. a meta - analysis by kwee and kwee, which included 16 primary studies, revealed no statistically significant differences in pooled sensitivity and specificity between tof - mra and ce - mra in detecting residual flow in the aneurysm. similarly, in the largest recently published prospective study with 311 patients by schaafsma., the areas under the receiver operating characteristic curves of the 2 methods were not statistically different. on the other hand, kaufmann recommend performing both ce - mra and tof - mra to increase the accuracy of the examination. the main disadvantage of tof - mra is its low sensitivity to slow and turbulent blood flow because of intravoxel dephasing and spin saturation. therefore, the slow residual flow within the coil mesh and tortuous remnants may not be detected due to signal loss, resulting in false - negative results. ce - mra better depicts areas of slow and turbulent flow and results in fewer flow - related artifacts. on the other hand, the use of contrast medium may cause an enhancement of the vasa vasorum and an organized thrombus, which is likely to produce false - positive results. finally, if a single long ce - mra acquisition is performed without well - timed contrast triggering, venous enhancement can significantly reduce image quality. in both tof - mra and ce - mra, a subacute thrombus, which has a high signal on t1-weighted images, may simulate the residual flow. theoretically, the use of the 4-dimensional tricks technique may help to overcome some shortcomings of the conventional static first - pass ce - mra in the follow - up of embolized aneurysms. since tricks offers dynamic images of blood flow, it may be more sensitive to areas of residual filling within the coil mesh. moreover, image contamination by venous enhancement may be avoided by selecting a proper inflow phase through comparison of consecutive phases. similarly, enhancement of the vasa vasorum and organized thrombus should be more clearly distinguished from aneurysm remnants. in our study tricks we noted a decrease of signal intensity in stented segments of parent arteries, which was related to susceptibility artifacts. similar artifacts have already been observed by several authors and the intensity of such artifacts seems to depend on the type of stent used for embolization. the application of time - resolved contrast - enhanced mra has been reported in the investigation of extracerebral aneurysms, arteriovenous malformations and dural arteriovenous fistulas, and as a cerebral venography technique [2023 ]. it was also tested as a method for imaging guidance in experimental aneurysm embolizations under mr control. to our knowledge, the diagnostic value of tricks and tof - mra in the follow - up of embolized intracranial aneurysms has not been previously compared. we found that although tricks images had significantly higher snr and cnr than tof - mra, which was a result of contrast medium administration, their quality scored lower. more importantly, tricks was only slightly more accurate in detecting the residual flow and in quantifying the status of aneurysm occlusion with auc values not statistically different. the received values of sensitivity and specificity of tricks (88.5%, 95% ci : 69.897.4% and 91.3%, 95% ci : 79.297.5%) are comparable to those of the conventional static ce - mra reported in the literature [812 ]. firstly, the sample size appears to be insufficient to demonstrate the significance of the difference between the diagnostic value of tricks and tof - mra. it still may be hypothesized that the demonstrated small difference in auc might appear significant in a larger population. secondly, there was a possibility to increase spatial resolution of tricks examinations ; however, this would result in a decrease of temporal resolution. since both parameters were considered important to our study, the applied settings present, in our opinion, a reasonable compromise. our results indicate that the use of time - resolved imaging of contrast kinetics does not improve the diagnostic value of mra in the follow - up of embolized intracranial aneurysms. because tof - mra has a similar diagnostic performance and does not expose patients to contrast media, it should be considered a first - line alternative to dsa in routine outpatient follow - up. | summarybackgroundthe use of contrast media and the time - resolved imaging of contrast kinetics (tricks) technique have some theoretical advantages over time - of - flight magnetic resonance angiography (tof - mra) in the follow - up of intracranial aneurysms after endovascular treatment. we prospectively compared the diagnostic performance of tricks and tof - mra with digital subtracted angiography (dsa) in the assessment of occlusion of embolized aneurysms.material/methodsseventy-two consecutive patients with 72 aneurysms were examined 3 months after embolization. test characteristics of tof - mra and tricks were calculated for the detection of residual flow. the results of quantification of flow were compared with weighted kappa. intraobserver and interobserver reproducibility was determined.resultsthe sensitivity of tof - mra was 85% (95% ci, 6596%) and of tricks, 89% (95% ci, 7097%). the specificity of both methods was 91% (95% ci, 7998%). the accuracy of the flow quantification ranged from 0.76 (tof - mra) to 0.83 (tricks). there was no significant difference between the methods in the area under the roc curve regarding both the detection and the quantification of flow. intraobserver reproducibility was very good with both techniques (kappa, 0.860.89). the interobserver reproducibility was moderate for tof - mra and very good for tricks (kappa, 0.740.80).conclusionsin this study, tof - mra and tricks presented similar diagnostic performance ; therefore, the use of time - resolved contrast - enhanced mra is not justified in the follow - up of embolized aneurysms. |
facial onset sensory and motor neuronopathy (fosmn) is a slowly progressive disorder characterised by facial sensory deficits which may spread to affect the neck, the upper trunk and the limbs, with the development later in the course of the disease of bulbar symptoms such as dysarthria and dysphagia, muscle weakness, cramps and fasciculation. because of these latter features, parallels between fosmn and motor neurone disease (mnd) have been drawn, although sensory features are not a feature of mnd and the onset and progression of fosmn appear to be slower than those of mnd. based on the limited currently available clinical and investigative evidence [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 ] and the lack of therapeutic response to immunosuppressive agents in most (but not all) cases, an underlying neurodegenerative process has been suggested in fosmn, although cases with neuropathological examinations are very few [2, 6, 9 ]. we report 3 further cases of fosmn, one with a post - mortem examination, suggesting that at least some of these cases fall within the spectrum of the transactive response dna binding protein 43 (tdp-43) proteinopathies. a 62-year - old man presented with a 3-year history of perioral numbness and paraesthesia progressing to involve all divisions of the trigeminal nerve bilaterally. over a similar interval twelve months prior to presentation, he described progressive slurring of speech, dysphagia and weight loss of 7 kg as well as complete loss of taste and smell. a neurological examination showed a decreased sensation to pinprick and light touch in all divisions of the trigeminal nerve bilaterally. there was wasting of the periscapular muscles bilaterally, with widespread fasciculation in the upper limbs and occasional fasciculation in the quadriceps bilaterally. reflexes were globally brisk with bilateral flexor plantar responses. normal or negative investigations included an autoantibody screen, anti - ganglioside antibodies, serum immunoglobulins, cerebrospinal fluid (csf) analysis (opening pressure, cell count, protein, glucose), and mri of the brain and the cervical spine. needle electromyography and nerve conduction studies (emg / ncs) showed widespread neurogenic changes without evidence of a neuropathy. the patient died at the age of 64, approximately 6 years after symptom onset. a neuropathological examination exhibited that the number of cervical, thoracic, and lumbar spinal motor neurones was reduced by approximately 40%. some of the remaining spinal cord motor neurones displayed characteristic intracytoplasmic extranuclear inclusions that stained positive for tdp-43 (fig. 1b) ; tdp-43 inclusions were also seen in hypoglossal nucleus motor neurones (fig. in addition, p62 and tdp-43-positive inclusions could be detected in neurones of the trigeminal nuclei (not shown). a 38-year - old woman presented with a 3-month history of right lower facial and oral cavity numbness. over the next 3 years, she developed sensory loss involving the upper and lower limbs as well as a wasting of the small muscles of the hand. she described decreased upper limb strength, and it progressed to a point when she was unable to wash her hair or dress without help. there was a progressive spread of sensory loss to her arms, neck and trunk. over the next 8 years, she developed lower limb weakness, more prominent distally than proximally ; she mobilised with a frame. there was fasciculation, global muscle wasting and flaccid weakness with finger drop of the ring finger and little finger on the right. in the lower limbs, there was a reduced pinprick and temperature sensation to the knees and elbows and over the trunk, with preserved joint position and vibration sensation. normal or negative investigations included autoantibody screen, anti - neuronal and anti - gm1 antibodies, serum protein electrophoresis, lysosomal storage enzymes, hiv and syphilis serology, csf examination, mri of the brain, and neurogenetic tests (pmp-22, p0, cmt - x, mitofusin, sca 1, 2, 3, 6, 7, 17, and frataxin). an mri of the spinal cord showed an atrophy of the cervical and thoracic cord with no evidence of a syrinx. a muscle biopsy (left quadriceps) showed denervation changes only, with no evidence of cox negative or abnormal nadh staining and no polyglucosan bodies. there was no clinical response to 3 monthly intravenous immunoglobulin (ivig) infusions given over 12 months. a 69-year - old man presented with a 4-month history of numbness affecting his left cheek, gradually progressing to involve the right cheek, tongue, jaw, and forehead, associated with difficulty swallowing. a neurological examination showed a reduced sensation to pinprick and light touch throughout the distribution of the trigeminal nerve bilaterally, and also over the tongue. an initial examination was otherwise normal, but over the following year, he developed wasting and fasciculation of the tongue and widespread wasting of the upper limbs. his dysphagia deteriorated over the same interval, causing a weight loss of 19 kg, requiring a percutaneous endoscopic gastrostomy insertion for nutritional support. normal or negative investigations included autoantibody screen, thyroid autoantibodies, onconeural and anti - glutamic acid decarboxylase antibodies, serum electrophoresis, serum angiotensin - converting enzyme, complement, hiv and lyme serology, brain mri, ct of the chest / abdomen / pelvis, bronchoscopy, and csf analysis. emg / ncs showed no neurogenic changes 1 year after symptom onset ; further electrophysiological examination after onset of the tongue and upper limb fasciculation was declined. there was no response to treatment with steroids and ivig ; treatment with riluzole was subsequently commenced. we have presented 3 cases with clinical and investigation features consistent with the syndrome of fosmn first described by vucic. in 2006, namely trigeminal sensory symptoms followed by a lower motor neurone disorder with bulbar onset (table 1). the characteristic features in the limited number of cases reported to date [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 ] are those of a sensory and motor neurone disorder, with sensory loss in the trigeminal nerve distribution, with subsequent peripheral facial weakness which may spread to affect other bulbar muscles, neck, upper and lower limbs. the disease is, with exceptions, usually slowly progressive (but with exceptions). neurophysiological findings in fosmn syndrome include diminished sensory nerve action potential amplitudes in the upper limbs. blink reflexes have also been noted to be abnormal in the majority of patients identified with fosmn (not examined in our cases). a selective loss of myelinated trigeminal nerve fibres with sparing of unmyelinated fibres has been reported. sensory impairment is detected in some patients with familial mnd associated with sod1 gene mutations [13, 14 ]. a case with the clinical and neurophysiological features of fosmn with a heterozygous d90a - sod1 mutation one case reported in the abstract by bosch. had neuronal loss and gliosis with tdp-43-positive cytoplasmic neuronal and glial inclusions in the hypoglossal nucleus and cervical motor neurones, as well as incidental changes of lewy body disease. the case presented by sonoda. showed a severe degeneration of the nuclei of the right trigeminal nerve and the right facial nerve as well as widespread tdp-43-positive glial inclusions in the brainstem tegmentum. neurones in the hypoglossal nerve nuclei were also shrunken and lost, with tdp-43-positive neuronal inclusions. neuronal loss and gliosis were prominent in the anterior horns, predominantly in the cervical cord, with tdp-43-positive skein - like inclusions. however, in contrast, vucic. found a widespread degeneration of sensory and motor neurones in 5 cases, but with no evidence of intraneuronal inclusions such as tdp-43, bunina bodies or ubiquitin inclusions, nor inflammation or amyloid deposition, and felt that novel mechanisms, unrelated to mnd, were involved. the neuropathological findings in our case 1 are similar to those reported by sonoda., with a widespread loss of spinal motor neurones and characteristic tdp-43 inclusions in some motor neurones, which also stained positive for p62 antibodies. in addition, tdp-43-and p62-positive inclusions could be detected in some neurones of the trigeminal nuclei. these data suggest that at least some fosmn cases fall within the spectrum of the tdp-43 proteinopathies, which encompasses mnd and some forms of frontotemporal dementia with or without mnd. fosmn may therefore represent a focal form of mnd (progressive course, affecting contiguous regions, fasciculation and denervation), but with slow onset and progression and a relatively good prognosis with the appropriate supportive care. to pursue this potential nosology, it might be of interest to examine cognitive function in fosmn cases, specifically looking for subtle subclinical signs of frontal dysfunction as found in some mnd cases. however, since fosmn has rightly been described as a syndrome, this does not exclude the possibility that other examples of fosmn may have a different pathogenesis, including possibly inflammatory disorders which may on occasion respond to immunotherapy. anti - ganglioside antibodies were checked in 2 of our patients (cases 1 and 2) and were negative. nevertheless, an assay of anti - ganglioside antibodies, especially those associated with facial and bulbar weakness (gd1a and gt1a respectively), might be reasonable in fosmn cases, although unlike fosmn, the associated clinical syndromes are not chronic progressive disorders. further neuropathological studies are critical to clarify disease mechanisms. we suggest that this might be facilitated by identifying possible cases of fosmn, for example cases currently being followed up with a diagnostic label of atypical or the possibility of identifying a subpopulation of patients with a better prognosis mandates searching mnd clinic databases for such patients as well as a careful review of the history for sensory symptoms in each new bulbar mnd case. | three patients with the clinical and investigation features of facial onset sensory and motor neuronopathy (fosmn) syndrome are presented, one of whom came to a post - mortem examination. this showed tdp-43-positive inclusions in the bulbar and spinal motor neurones as well as in the trigeminal nerve nuclei, consistent with a neurodegenerative pathogenesis. these data support the idea that at least some fosmn cases fall within the spectrum of the tdp-43 proteinopathies, and represent a focal form of this pathology. |
a 49-year - old man with a history of sick sinus syndrome presented with quadriplegia and ophthalmoplegia. brain magnetic resonance imaging (mri) and an angiography examination, which were performed a day after quadriplegia, revealed acute brain infarction in the bilateral midbrain, right median thalamus, and superior cerebellum associated with the distal basilar artery occlusion. it is also unclear whether the mechanism of symptomatic bruxism is identical with that of idiopathic sleep bruxism. it has been shown that rhythmic jaw movement is generated by a neuronal activation in the brainstem of animals.7 rhythmic firing of interneurons in the pontine reticular formation (prf) and a connection between the oral motor nuclei and the prf have been observed.7 - 10 rodents move their jaws continuously and cows ruminate throughout the day. however, the activity of the generator is so weak that the release from high cortical inhibition during normal sleep may not be sufficient to cause bruxism. thus, the release phenomenon due to sleep and other factors such as dental problems, smoking, alcohol, and the coma state6 may cause bruxism. in our case, bilateral midbrain infarction may have caused the interruption of higher cortical inhibition and damaged the dentato - rubro - olivary pathway. although higher cortical inhibition is interrupted, the brainstem generator may not be sufficient to cause bruxism. additional damage to the dentato - rubro - olivary pathway may cause bilateral olivary hypertrophy, which can stimulate the prf. because no connection between the oral motor nuclei and the inferior olivary nuclei has been observed in animal study, we do not think that the hypertrophied olivary nucleus directly stimulates the motor nucleus in the brainstem.8 instead, hyperactive bilateral prfs may cause bruxism. pollack and cwik have reported bruxism after cerebellar hemorrhage,5 which may also be related to the damage to the dentato - rubro - olivary pathway. unlike palatal myoclonus, bruxism requires bilateral harmonic rhythmic contraction and relaxation of involved muscles. since the neurons in the prf project to both the trigeminal motor nuclei,8 the prf may induce the contraction of one side and relaxation of the opposite side. on the other hand, the normal side can influence both we suspect that this is a reason why bruxism is very rare in patients with brainstem infraction. in conclusion, furthermore, we suggest that the human bruxism generator may be located in the prf. large bilateral midbrain lesions that interrupt cortical inhibition seem to produce bilateral olivary hypertrophy, resulting in bruxism in the presence of the intact pontine generator. | delayed - onset continuous bruxism due to brain stem infarction has not yet been reported. a 49-year old man presented with quadriplegia and ophthalmoplegia. brain mri showed acute infarction in the bilateral midbrain, right thalamus and the superior cerebellum. one month later, the patient developed bruxism which persisted during sleep. a palatal myoclonus was not observed. follow up mri taken 4 months later showed bilateral olivary hypertrophy. we suggest that the patient 's bruxism may be related to the olivary hypertrophy. the bruxism generator may be located in the pontine - reticular - formation (prf). bilateral large midbrain lesions interrupting the cortical inhibition may have produced bilateral olivary hypertrophy, which could stimulate the prf, producing continuous bruxism. |
although surgery is recommended for ptc, there is no consensus on the therapy when a thyroidectomy is contraindicated because of systemic disease such as heart failure or chronic obstructive pulmonary disease. hypertrophic cardiomyopathy is a common genetic cardiovascular disease with a high risk of sudden death and disability (1). given the potential devastating perioperative cardiac complications, hypertrophic cardiomyopathy is generally a contraindication for anesthesia and surgery (2). radiofrequency ablation (rfa) has been used widely in the treatment of solid cancers (3). herein, we presented a case of ptc in a patient with hypertrophic cardiomyopathy treated with rfa. neck ultrasound performed for a 52-year - old female revealed a predominantly solid nodule (0.9 0.7 0.5 cm) with marked hypoechogenicty, microcalcification, moderate vascularity, and spiculated margin in the right thyroid gland. total thyroxine (tt4) and total triiodothyronine (tt3) were 109.60 nmol / l (55.47161.25 nmol / l) and 1.16 nmol / l (1.022.96 nmol / l) ; free thyroxine (ft4) and free triiodothyronine (ft3) were 14.63 pmol / l (10.4524.38 pmol / l) and 4.36 pmol / l (2.776.31 pmol / l), respectively. thyroid - stimulating hormone (tsh) and thyroid peroxidase antibody (tpo - ab) were 1.58 miu / l (0.3804.340 miu / l) and 852.0 iu / ml (0100 iu / ml), respectively. seven years earlier, the patient had been diagnosed with hypertrophic cardiomyopathy and a ddd cardiac pacemaker was implanted. a cardiac ultrasound showed diffuse thickening of the ventricular walls and the left ventricular ejection fraction was 60%. the n - terminal pro - brain natriuretic peptide was 1048 pg / ml (0100 pg / ml). core needle biopsy (18 g needle) confirmed the diagnosis of ptc (fig. the patient was considered unable to tolerate a thyroidectomy, so instead rfa was performed. we used valleylab cool - tip rfa system (boulder, co, usa), including monopolar electrode, radiofrequency generator and cool - tip pump. after sterilization and local anesthesia with 2% lidocaine, the ablation electrode was inserted into the nodule under ultrasound guidance. the ablation was started with 5 w and increased to 28 w gradually in a 1 cm active tip. it was terminated when the rfa - induced transient hyperechoic zone covered the entire carcinoma and the needle passage was also ablated when the ablation electrode was retracted. regular follow - up neck ultrasound showed no signs of recurrence or metastases after 1, 3, 15, and 41 months ; and the patient had no complications of rfa (fig. the size of ablated lesion was reduced and the echogenicity was decreased ; in addition, the tt4 and tt3 were 73.20 nmol / l (55.47161.25 nmol / l), respectively ; ft4 and ft3 were 14.02 pmol / l (10.4524.38 pmol / l) and 3.76 pmol / l (2.776.31 tsh and tpo - ab were 0.97 miu / l (0.3804.340 miu / l) and 670.70 iu / ml (0100 iu / ml) ; respectively. ptc is the most common subtype of thyroid cancer, comprising > 80% malignant thyroid neoplasms. although the prognosis is excellent, the guidelines of the national comprehensive cancer network for thyroid carcinoma and the european thyroid association (eta) both recommend a total thyroidectomy or lobectomy plus isthmusectomy as the standard treatment for ptc (56). a non - surgical or minimally invasive treatment is required in thyroid cancer patients who can not undergo surgery due to severe disease, such as hypertrophic cardiomyopathy. as minimally invasive therapy, rfa induces irreversible damage to tumor tissue with heat generated by high - frequency alternating electric current (7). rfa is an established substitute for surgery for solid cancers such as hepatic cancer (3). rfa is also used to treat benign thyroid nodules and metastatic or recurrent well - differentiated thyroid cancer with difficult reoperations (89). the residual volume after rfa is reduced significantly in benign thyroid nodules and metastatic well - differentiated thyroid carcinoma (89). however, whether rfa is a promising therapeutic option for papillary thyroid microcarcinoma (ptmc), which defined as thyroid cancer 10 mm in diameter, is unclear. (10) proposed the moving shot technique (mst) for ablation of thyroid nodules by moving the electrode during the procedure. compared with fet, mst is more suitable for thyroid gland since it can minimize the risk of heat damage to surrounding critical structures such as recurrent laryngeal nerve, blood vessels and esophagus (11). however, at the time, mst was not in use for thyroid nodules in our hospital, and may have been more suitable for this patient. eta and the american association of clinical endocrinologists recommend partial thyroidectomy and lobectomy plus isthmusectomy for ptmc without neck lymph nodes involvement respectively (512). in our case, a calcified 0.9 0.7 0.5 cm nodule without enlarged lymph nodes was detected and core needle biopsy confirmed papillary thyroid cancer, so surgery was necessary for the patient. although surgery is the main therapy for ptmc, our case demonstrates that rfa can be a substitute in patients who can not tolerate surgery. however, neck lymph nodes metastases are quite common for thyroid cancer and central node involvement reportedly exist in 64% of ptmc cases (13). therefore, for operable thyroid cancer, rfa should be avoided because of undetectable lymph node metastases and patients undergoing rfa as an alternative to surgery should be followed closely. signs of recurrence or metastases have not been observed on periodical follow - up neck ultrasound in our patient. however, further observation and clinical trials are needed to compare the value of rfa with surgery. rfa may be a reliable therapeutic candidate even for low - risk ptc patients without contraindication of surgery. in conclusion, to our knowledge, this is the first reported case of ptc with hypertrophic cardiomyopathy treated with rfa. despite thyroidectomy as prior therapy in our case, rfa is an alternative when surgery is not feasible. however, further long - term observation is needed to confirm the value of rfa in the treatment of thyroid cancer. | standard therapy has not been established for thyroid cancer when a thyroidectomy is contraindicated due to systemic disease. herein, we reported a patient who had hypertrophic cardiomyopathy and papillary thyroid carcinoma treated by radiofrequency ablation because of inability to tolerate a thyroidectomy. radiofrequency ablation can be used to treat thyroid cancer when surgery is not feasible, although the long - term outcome needs further observation. |
non - gestational choriocarcinomas are rarely seen outside the gonads, with the mediastinum being the main site for these non - gestational extragonadal choriocarcinomas. there is no consensus regarding the use of systemic chemotherapy [1, 2 ]. studies undertaken on treatment for the metastatic disease indicate that chemotherapies based on cisplatin, methotrexate or 5-fu are not efficient [1, 2 ]. there is no metastatic gastric choriocarcinoma case in the literature that showed a complete response to chemotherapy. herein, we present a human epidermal growth factor receptor-2 (her2)-positive gastric adenocarcinoma case which has a choriocarcinomatous component and showed a complete response to trastuzumab chemotherapy. a 57-year - old female patient was admitted for weakness, lack of appetite, weight loss and abdominal pain. the patient did not have a disease history and had not been under any medical treatment. on physical examination the mucosa was pale and no abdominal mass was detected. laboratory analysis revealed hypochromic, microcytic anemia (hb : 9 g / dl). upper endoscopic examination revealed a mass in the gastric antrum, which was reported to be adenocarcinoma by biopsy. postoperative pathological analysis revealed the presence of adenocarcinoma associated with choriocarcinoma ; histologically, intestinal type adenocarcinoma composed of columnar gland - forming cells interspersed with cytotrophoblast and syncytiotrophoblast cells staining positive for beta - human chorionic gonadotropin (-hcg) on immunohistochemistry (fig. 1, fig. 2). the patient 's serum -hcg level, which was measured in light of these pathological findings, was 22.823 iu / ml. multiple liver metastases and a metastasis in the right iliac bone were detected on pet - ct imaging for tumor staging. the patient was given two cycles of dcf (docetaxel, cisplatin, 5-fu) as treatment. however, the patient did not tolerate the treatment due to the development of grade 3 diarrhea and mucositis. therefore, the dcf treatment was replaced with a combination of docetaxel, carboplatin and trastuzumab. -hcg level had decreased to 6 iu / ml, and pet - ct scans showed a complete response (fig. the patient is currently on the 24th month of the treatment and the complete response is still ongoing. the most widely accepted theory holds that the trophoblastic cells in gastric choriocarcinoma develop from dedifferentiation of a poorly differentiated adenocarcinoma. in fact, cytogenetic studies show that gastric choriocarcinoma genetically possesses characteristics of both adenocarcinoma and choriocarcinoma. in our patient choriocarcinoma accompanied adenocarcinoma and therefore, pathological analysis of the biopsy sample by an experienced pathologist increases the chance of establishing a diagnosis. consecutive measurements of serum -hcg levels in the postoperative or post - chemotherapy periods are valuable for the assessment of treatment response or recurrence of the disease. the most common metastasis sites are lymph nodes (87%), followed by liver (45%), peritoneum (23%) and lungs (8%). gastric choriocarcinomas are highly malignant and most patients die within a year of diagnosis. although more than 140 gastric choriocarcinoma cases have been reported in the literature until now, there is no consensus concerning the treatment strategy for the disease. in addition to surgery and radiotherapy, various cytotoxic drugs have been used for the treatment. however, contrary to gestational choriocarcinomas, all chemotherapy regimens were found to be ineffective in metastatic gastric choriocarcinoma. a choriocarcinoma case who received trastuzumab therapy was not found in the literature. in gastric cancers however, her2-positive gastric cancer patients benefit significantly from trastuzumab therapy. when compared with normal placenta or her2 expression furthermore, choriocarcinoma components showed significantly higher her2/neu expression compared to other histological subtypes in testicular germ cell tumors (p = 0.0095). these data suggest that cerbb2 oncoprotein may be important in the pathogenesis of choriocarcinoma, but there is no information concerning the use of trastuzumab for the treatment. overexpression was present in our case and complete response was obtained after adding trastuzumab to the treatment. in order to establish a preoperative diagnosis for gastric choriocarcinoma, it is important to bear this tumor in mind and adopt a skeptical approach. most patients have metastases at the time of establishing a diagnosis and the tumor has a significantly poor prognosis. determining her2 expression in every patient and using trastuzumab treatment in positive cases may lead to positive therapeutic outcomes, as in our case. | gastric choriocarcinoma is a rare neoplasm and usually accompanies gastric adenocarcinoma. the prognosis is poor due to the aggressive course of the disease. a 57-year - old female patient with weight loss and abdominal pain was examined. the patient was operated following the examination, and pathological analysis revealed the presence of a gastric adenocarcinoma associated with choriocarcinoma. immunohistochemical analysis showed a positive reaction with antibodies to beta - human chorionic gonadotropin and overexpression of the cerbb2 proto - oncogene. staging revealed multiple metastases in the liver. a complete response was obtained with a combination of trastuzumab and chemotherapy. the diagnosis of gastric choriocarcinomas without pathological examination is difficult due to their rare occurrence. a complete response can be obtained with trastuzumab in the treatment of cases with overexpression of the cerbb2 protein. |
nonalcoholic fatty liver disease (nafld) is the terminology used for a wide spectrum of disorders ranging from simple steatosis to progressive nonalcoholic steatohepatitis (nash), hepatic fibrosis and cirrhosis and its diagnosis in clinics is based on ultrasonography (1, 2). although, the actual prevalence of nafld remains unknown (3), the prevalence of nafld ranges from about 20% - 35% in the western population and about 19% - 32% in asian population (4), with the prevalence being higher (70% - 90%) in obese individuals (5). one study reported that the prevalence of nash in iranian males is twice than females (6). nonalcoholic fatty liver disease is characterized by elevated liver enzymes including alanine amino transferase (alt) and aspartate amino transferase (ast) and also, build - up of fat within liver cells (7). obesity, sedentary lifestyle and insulin resistance are well - established risk factors for nafld ; however, the pathogenesis of nafld is incompletely understood and factors that determine disease severity remain unclear (8). although, the severity of fatty liver was positively related to anthropometric measurements including body mass index (bmi), waist and hip circumference, subcutaneous adipose tissue thickness and hypertriglyceridaemia (3, 9) currently, there is no specific drug therapy approved for the treatment of nafld and management focus on treatment of the metabolic syndrome rather than nafld as an individual entity (10). lifestyle change and physical activities are currently the main recommendation for people with nafld. lifestyle interventions in the form of calorie restriction and increasing the physical activity level with an aim to reduce weight remain the cornerstone of treatment for patients with nafld (11). exercise training (et) is a major component of treatment for nafld (8) as recommended by the american gastroenterological association (12). however, the role of et in the treatment of this condition has not been thoroughly investigated and only few studies have investigated the effect of et on nafld, usually in combination with diet and weight loss (4, 13 - 18). exercise training has been shown to reduce the risk of insulin resistance, aminotransferase levels, dyslipidemia, and impaired fasting glucose and can be beneficial for glucose - lipid metabolism (8, 19). aerobic and resistance exercise can be therapeutic in reducing liver fat deposition by increasing energy expenditure, improvement in skeletal lipid oxidation, reduction in total and abdominal adiposity, reduction in subcutaneous fat and free fatty acid flux to liver (4, 14, 19 - 21). overall, there is very limited data on the effectiveness of aerobic and resistance exercise on hepatic function in nafld. (17) demonstrated a significant reduction in aminotransferase levels and liver fat in patients with nash who adhered to an aerobic exercise program. the results of one study demonstrated that, short - term exercise can target hepatic lipid composition, which may reduce the risk of nafld progression (16). (15) present that the long - term exercise therapy along with aerobic and resistance therapy was significantly effective in improving noninvasive biomarkers of nafld. in another study, damor. (4) present that moderate intensity progress resistance training is associated with significant improvement in hepatic fat, subcutaneous fat and insulin sensitivity in patients with nafld. (14) evaluated the effects of aerobic exercise on liver enzymes and hepatic fat in subjects with nafld. they reported that after eight weeks, aminotransferase levels and hepatic fat were significantly reduced in the aerobic group. so far, to the best of our knowledge, there are no data on the effect of aerobic and resistance exercise on liver aminotransferase levels and hepatic fat among the iranian men with nafld ; therefore, this study was undertaken. the present study was conducted to examine the effect of aerobic and resistance exercise training on liver enzymes and hepatic fat in men with nafld in iran. in this randomized clinical trial study, subjects were randomly selected from the liver clinic in the department of gastroenterology / hepatology at baqiyatallah hospital in tehran city, iran. sample size estimation was performed through single proportion formula with 95% confidence interval and the calculated sample size was 30. inclusion criteria including men with hepatic steatosis, which was confirmed by ultrasonography with acceptable sensitivity and specificity and was based on a hepatic triglyceride content greater than 5% (22). exclusion criteria were identified as genetic, metabolic or endocrine diseases (15), alcohol consumption 30 g / day (13), heart and pulmonary disease, patients with chronic hepatitis b and c, autoimmune hepatitis, drug abuse, and patients with diabetic mellitus and fasting hyperglycemia. the study protocol was approved by the human research ethics committees of the baqiyatallah university of medical sciences (january 5, 2014 with code no : 34). an informed consent was obtained from all patients, including agreement of the patients to participate as volunteers. the patients were then divided into three equal groups, aerobic, resistance and control groups (n = 10 in each group). during the 8 week intervention period, an aerobic training (at) program including a 45 minute session three times a week (135 min / week) under the supervision of an exercise physiologist and sport medicine. aerobic exercise consists of three phases : warm - up, training and cool down. at the beginning of exercise session, subjects had a ten minute warm - up. the warm - up protocol was consisted of stretching movements and slowly running on treadmill. then, the warm - up phase was followed by the training phase. at baseline, the training phase commenced with two 15 minute running on treadmill at 60% of their maximal heart rate (mhr) in the first week and increased to two 15 minute running on treadmill at 75% mhr per week by the final week of training (23). to assure that the desired heart rate (exercise intensity) was achieved and maintained for 30 minute, during the aerobic sessions, each participant underwent heart - rate monitoring with polar (model : ft1) heart rate monitor (24). maximum heart rate was calculated using the formula (25) : resistance training was performed during 8-weeks with thrice weekly sessions on nonconsecutive days. the program consisted of seven exercises : triceps press, biceps curl, calf raise, leg press, leg extension, lat pull down and sit - ups (21). each session lasted approximately 45 minute and consisted of a 5 minute warm - up with stretching followed by resistance exercise done as a circuit, ending with 5 minute cool down. the 1 repetition maximum (1rm) was measured at baseline and following the intervention (26). initially, participants did two circuits using 50% of their 1rm and repeated them 10 times for the first and second weeks, progressing to two circuits, using 60% of their 1rm and repeated 10 times for the third and fourth weeks. in fifth and sixth weeks, participants did three circuits using 60% of their 1rm and repeated 10 times. in the last two weeks, patients did three circuits using 70% of their 1rm and repeated 10 times (27). a 90-second rest was allowed between sets of exercises. at three preliminary sessions then, anthropometric components and body composition elements of any patient were determined in the start and the end of the study. waist circumference and hip circumference were measured to the nearest 0.5 cm with a nonelastic tape measure. to calculate the subcutaneous fat, the pectoral, abdominal and thigh skin fold were measured using the slim guide skin fold caliper (model : ac-6575) on the dominant side of the body (28). also, fat mass of whole body, bmi and weight of any patient were determined using the body composition analyzer (model : tanita, bc-418). subjects did not perform any exercise 48 hour before testing and were on 12 hours fasting prior to testing. blood samples were taken from the antecubital vein and collected in heparinized tubes and analyzed for liver enzymes (alt and ast) or frozen and stored at -70c for subsequent analysis of plasma glucose and insulin. the alt and ast enzymes levels were measured by biosystem kits (biosystem s.a., sonography was used to measure liver fat and performed by one radiologist in all subjects with the same equipment at baqiyatallah hospital. fatty liver was diagnosed via abdominal ultrasonography (us) using standardized criteria (30). grade 0 (no steatosis), grade one (mild) slightly increased echogenicity, grade two (moderate) moderately increased echogenicity and grade three (severe) markedly increased echogenicity (31). following the 8-week exercise training intervention, subjects repeated the same tests in the same manner and order. to prevent the acute effects of exercise training altering posttraining test results, moreover, the fasting insulin level was measured using a chemiluminescent immunoassay (liaison insulin assay, diasorin, saluggia, italy), and samples were analyzed on the liaison analyzer (diasorin). the homeostasis model assessment of insulin resistance (homa - ir), a measure of insulin resistance, was determined according to the following equation (33) : the control group had no exercise training program during the 8-week period of the study. when significance occurred, a tukey s honestly significant difference (hsd) post - hoc test was used to determine the source of the difference. in this randomized clinical trial study, subjects were randomly selected from the liver clinic in the department of gastroenterology / hepatology at baqiyatallah hospital in tehran city, iran. sample size estimation was performed through single proportion formula with 95% confidence interval and the calculated sample size was 30. inclusion criteria including men with hepatic steatosis, which was confirmed by ultrasonography with acceptable sensitivity and specificity and was based on a hepatic triglyceride content greater than 5% (22). exclusion criteria were identified as genetic, metabolic or endocrine diseases (15), alcohol consumption 30 g / day (13), heart and pulmonary disease, patients with chronic hepatitis b and c, autoimmune hepatitis, drug abuse, and patients with diabetic mellitus and fasting hyperglycemia. the study protocol was approved by the human research ethics committees of the baqiyatallah university of medical sciences (january 5, 2014 with code no : 34). an informed consent was obtained from all patients, including agreement of the patients to participate as volunteers. the patients were then divided into three equal groups, aerobic, resistance and control groups (n = 10 in each group). during the 8 week intervention period, an aerobic training (at) program including a 45 minute session three times a week (135 min / week) under the supervision of an exercise physiologist and sport medicine. aerobic exercise consists of three phases : warm - up, training and cool down. at the beginning of exercise session, subjects had a ten minute warm - up. the warm - up protocol was consisted of stretching movements and slowly running on treadmill. then, the warm - up phase was followed by the training phase. at baseline, the training phase commenced with two 15 minute running on treadmill at 60% of their maximal heart rate (mhr) in the first week and increased to two 15 minute running on treadmill at 75% mhr per week by the final week of training (23). to assure that the desired heart rate (exercise intensity) was achieved and maintained for 30 minute, during the aerobic sessions, each participant underwent heart - rate monitoring with polar (model : ft1) heart rate monitor (24). resistance training was performed during 8-weeks with thrice weekly sessions on nonconsecutive days. the program consisted of seven exercises : triceps press, biceps curl, calf raise, leg press, leg extension, lat pull down and sit - ups (21). each session lasted approximately 45 minute and consisted of a 5 minute warm - up with stretching followed by resistance exercise done as a circuit, ending with 5 minute cool down. the 1 repetition maximum (1rm) was measured at baseline and following the intervention (26). initially, participants did two circuits using 50% of their 1rm and repeated them 10 times for the first and second weeks, progressing to two circuits, using 60% of their 1rm and repeated 10 times for the third and fourth weeks. in fifth and sixth weeks, participants did three circuits using 60% of their 1rm and repeated 10 times. in the last two weeks, patients did three circuits using 70% of their 1rm and repeated 10 times (27). a 90-second rest was allowed between sets of exercises. at three preliminary sessions, subjects came to the laboratory to familiarize with the training equipment and procedure. then, anthropometric components and body composition elements of any patient were determined in the start and the end of the study. waist circumference and hip circumference were measured to the nearest 0.5 cm with a nonelastic tape measure. to calculate the subcutaneous fat, the pectoral, abdominal and thigh skin fold were measured using the slim guide skin fold caliper (model : ac-6575) on the dominant side of the body (28). also, fat mass of whole body, bmi and weight of any patient were determined using the body composition analyzer (model : tanita, bc-418). subjects did not perform any exercise 48 hour before testing and were on 12 hours fasting prior to testing. blood samples were taken from the antecubital vein and collected in heparinized tubes and analyzed for liver enzymes (alt and ast) or frozen and stored at -70c for subsequent analysis of plasma glucose and insulin. the alt and ast enzymes levels were measured by biosystem kits (biosystem s.a., barcelona, spain) and through the spectrophotometry method (29). sonography was used to measure liver fat and performed by one radiologist in all subjects with the same equipment at baqiyatallah hospital. fatty liver was diagnosed via abdominal ultrasonography (us) using standardized criteria (30). grade 0 (no steatosis), grade one (mild) slightly increased echogenicity, grade two (moderate) moderately increased echogenicity and grade three (severe) markedly increased echogenicity (31). following the 8-week exercise training intervention, subjects repeated the same tests in the same manner and order. to prevent the acute effects of exercise training altering posttraining test results, barcelona, spain), which is an enzyme colorometric test without deproteinization. moreover, the fasting insulin level was measured using a chemiluminescent immunoassay (liaison insulin assay, diasorin, saluggia, italy), and samples were analyzed on the liaison analyzer (diasorin). the homeostasis model assessment of insulin resistance (homa - ir), a measure of insulin resistance, was determined according to the following equation (33) : the control group had no exercise training program during the 8-week period of the study. when significance occurred, a tukey s honestly significant difference (hsd) post - hoc test was used to determine the source of the difference. an informed consent was obtained from 30 patients and they were enrolled in the study. table 1 shows anthropometric and body composition data of subjects with nafld before and after interventions. however, weight (kg) and bmi (kg / m) were improved significantly only in the resistance exercise group. repeated measure anova analyses showed a significant difference regarding mean alt, ast changes between the groups (table 2). post - hoc analyses showed significant differences in alt, ast and hepatic fat between the control and aerobic groups, and the control and resistance groups (table 3). basal fatty liver that was diagnosed by sonography, after intervention, was significantly decreased in the aerobic and resistance exercise groups. however, in the control group, the liver fat content was slightly increased after 8weeks (figure 1). moreover, after training intervention, the aerobic group only presented significantly lower values of homa - ir compared to the control group (figure 2). abbreviations :, is differences between post and baseline (mean of changes) ; alt, alanine transaminase ; alp, alkaline phosphatase ; ast, aspartate transaminase. for some time we have been interested in how much exercise training, what types (modes) of exercise and what exercise intensity are most beneficial for peoples with nafld. although, it is a fact that not any one amount or type of exercise is likely to be best for patients with nafld (34). in this study, we compare the effects of aerobic and resistance exercise on hepatic fat and liver enzymes in peoples with nafld. because, it is important for the clinician to understand whether resistance or aerobic training is superior in inducing changes in hepatic fat liver enzymes and body composition in individuals with nafld. an 8-week aerobic and resistance exercise program brought about a significantly reduction in liver fat and improving in fasting insulin resistance (homa). this was accompanied by a significantly increase in insulin sensitivity, and decreased alt and ast levels after aerobic exercise in the absence of any change in body weight. although in the resistance group, these changes were associated with a significant reduction in body weight and bmi. our findings are consistent with previous studies that observed a decrease in hepatic fat following aerobic exercise in people with nafld. (14) demonstrated that hepatic fat and the serum ast and alt levels were reduced after 8 weeks aerobic exercise. (35) demonstrated that a 12-week aerobic exercise program without weight loss or change in bmi, results in reduced visceral and hepatic fat content, and decreased insulin resistance in obese adolescents. chen. (36) in their study showed that insulin resistance and hepatic fat were significantly decreased after a 10-week aerobic exercise. haus. (16) reported aerobic exercise can target hepatic fat, which may reduce the risk of nafld progression. they have suggested that the improvement in hepatic lipid composition may be driven by adiponectin, fat oxidation and increase on insulin sensitivity. (21) expressed that the mechanisms underlying the change in hepatic fat following exercise training are likely to reflect changes in insulin sensitivity, circulatory lipids and energy balance. our findings would support other reports that exercise training increases body glucose disposal at least partly due to increases expression of glut4 in skeletal muscles, insulin receptor and glycogen storage (37). also, moderate to vigorous exercise training increases fatty acid oxidation from adipose, intramyocellular, and possibly hepatic sources (38). (21) reported that an 8-week resistance exercise program improves nafld (reduction in liver lipid and homa - ir) independent of any change in body weight. in this study, we found significant reductions in alt and ast levels, independent of weight loss, after 8weeks of aerobic exercise in men with nafld. although in resistance training, reduction in alt and ast were dependent to weight loss and decrease in bmi. similar findings have been reported previously about the relation between aerobic exercise training with alt and ast (17) and also physical activity and alt in nafld (32). although limited number of studies have explored the role of aerobic and resistance exercises on alt and ast levels in patients with nafld. de piano. (15) compared the effectiveness of resistance and aerobic (at + rt) with aerobic exercise in obese adolescents with nafld. in those who underwent resistance and aerobic exercise, presented lower alt after intervention compared with aerobic training. (19) also, reported that moderate intensity aerobic exercise helps in normalizing alt levels in patients with nafld. comparisons between aerobic and resistance training groups in the current study suggest that resistance training decreases both body weight and bmi significantly more than aerobic training. the lack of body mass loss observed with aerobic training in this study supports the findings of others and is likely driven by an increase in lean body mass (39 - 41). finally, this study demonstrated that 8 weeks of exercise training favorably decreases abdominal obesity (as measured by waist circumference), body fat and fat mass and greatly improves hip circumference and abdominal subcutaneous fat in aerobic and resistance groups. surprisingly, however, other markers of adiposity, such as pectoral and thigh subcutaneous fat were unaltered at the end of the study. in one study, bell. reported that an 8-week combined aerobic and resistance exercise program without weight loss resulted in decreased insulin resistance and reduced waist circumference in sedentary obese individuals (42). also, with regard to body composition, gutin and owens observed that a 12-week aerobic exercise program attenuated growth - related increase in abdominal subcutaneous fat and visceral fat accumulation compared to the control group (43). in another study, gutin. (44) demonstrated that an 8-month program of physical activity combined with lifestyle education decreased abdominal subcutaneous fat and visceral fat content. our results indicate that aerobic exercise without weight loss results in decreased abdominal subcutaneous fat and visceral fat content but not pectoral and thigh subcutaneous fat. we postulate that this is due to the fact that abdominal subcutaneous and visceral fat is more metabolically active (35, 45). first, the small size of patients can be considered as a limitation of study. undoubtedly, study of broader spectrum of nafld patients is necessary to increase the external validity of our findings. second, in the present study, nafld was not diagnosed based on histology ; so, the fat content was not measured bybiopsy. third, an important limitation of this study is that hepatic fat measures obtained from us, similar to other reports (46, 47), while highly correlated to liver fat measures from magnetic resonance spectroscopy (mrs) and liver biopsy studies (48, 49) are not direct measures of liver fat. however, the changes in hepatic fat are very similar to the patterns of change across the two exercise groups in alt, ast, waist and hip circumference, abdominal subcutaneous fat and homa - ir. in conclusion, the results of this randomized controlled trial demonstrate that 8 weeks of aerobic training and resistance training are equally effective in reducing hepatic fat content and liver enzymes levels (alt and ast) in patients with nafld. interestingly, in the aerobic group, these changes are independent of weight loss and decrease of bmi. our data indicate that exercise training (aerobic and resistance) can provide benefit for the management of nafld. | background : nonalcoholic fatty liver disease (nafld) has different prevalence rates in various parts of the world and is a risk factor for diabetes and cardiovascular disease that could progress to nonalcoholic steatohepatitis, cirrhosis, and liver failure.objectives:the current study aimed to investigate the effect of aerobic training (at) and resistance training (rt) on hepatic fat content and liver enzyme levels in iranian men.patients and methods : in a randomized clinical trial study, 30 men with clinically defined nafld were allocated into three groups (aerobic, resistance and control). an aerobic group program consisted of 45 minutes of aerobic exercise at 60% - 75% maximum heart rate intensity, a resistance group performed seven resistance exercises at intensity of 50% - 70% of 1 repetition maximum (1rm) and the control group had no exercise training program during the study. before and after training, anthropometry, insulin sensitivity, liver enzymes and hepatic fat were elevated.results:after training, hepatic fat content was markedly reduced, to a similar extent, in both the aerobic and resistance exercise training groups (p 0.05). in the two exercise training groups, alanine amino transferase and aspartate amino transferase serum levels were significantly decreased compared to the control group (p = 0.002) and (p = 0.02), respectively. moreover, body fat (%), fat mass (kg), homeostasis model assessment insulin resistance (homi - ir) were all improved in the at and rt. these changes in the at group were independent of weight loss.conclusions:this study demonstrated that rt and at are equally effective in reducing hepatic fat content and liver enzyme levels among patients with nafld. however, aerobic exercise specifically improves nafld independent of any change in body weight. |
a previously healthy 19-year - old woman from alberta, canada, returned from australia with increasing fatigue, fever, lethargy, and confusion. she had spent 6 months in new zealand as part of an agricultural exchange, in which her activities included hay bundling, heavy machinery operation, and manure management but no direct zoonotic contacts. before returning to canada she flew to darwin, in the tropical region (top end) of northern territory, and then left on a 3-day tour of kakadu, mary river, and litchfield national parks. she then took a bus to alice springs, where she spent another 3 days touring local sites, after which she flew from alice springs to calgary, alberta, canada, through sydney, australia ; auckland, new zealand ; and los angeles, california, usa. symptoms of excessive fatigue developed the day of her return to canada (day 1) and were initially attributed to jet lag. the next day the patient was admitted to a rural community hospital where empiric high - dose intravenous ceftriaxone, vancomycin, and acyclovir were administered. because of progressive neurologic deterioration, the patient was airlifted to foothills medical centre in calgary. on arrival (day 3), she was febrile (temperature 39.7c) and lethargic and showed worsening confusion, incomprehensible speech, inappropriate verbal responses, and a fluctuating level of consciousness. at examination, she had mild tachypnea. results of computed tomography (ct) of the brain were within reference ranges (figure 1, panel a). gadolinium - enhanced magnetic resonance imaging showed areas of restricted diffusion in the splenium of the corpus callosum and t2 flipped attenuation inversion recovery sequence hyperintensity in the posterior aspects of both thalami (figure 1, panel b). high - dose intravenous meropenem was given because of possible melioidosis encephalomyelitis, which has been reported in the top end of northern territory (2). neuroimaging during course of illness for a patient with a fatal infection of murray valley encephalitis virus imported from australia to canada, 2011. each image corresponds to an axial cross - section through the thalamus and basal ganglia. b) magnetic resonance imaging (t2 flipped attenuation inversion recovery sequence) at day 3 showing abnormalities in the posterior thalami and splenium of the corpus callosum. c) ct when a fixed, dilated, right pupil (day 8) developed in the patient showing marked thalamic hypo - density and obstructive hydrocephalus. d) ct before death (day 10) showing necrosis of both thalami and a dilated left lateral ventricle. the patient became increasingly agitated and had worsening hypoxemia, which required transfer to the intensive care unit for tracheal intubation and mechanical ventilation. results of repeat chest radiography were consistent with development of the acute respiratory distress syndrome. on day 4, she began to show decerebrate posturing with increased deep tendon reflexes, diffuse rigidity, unresponsiveness, and a downward gaze preference. repeat ct of the brain showed evolving hypodensity of both thalami with extension into the brainstem. on day 5, a presumptive diagnosis of mve was made on the basis of results obtained for csf by reverse transcription pcr. primers specific for flavivirus nonstructural protein 5 coding region (3) yielded a 770-nt sequence obtained from a 863-bp amplicon, which showed 98% identity with that of murray valley encephalitis virus (mvev) strain 151 (genbank accession no. serum samples collected on day 4 and tested by using an elisa were positive for mvev igm but negative for igg and neutralizing antibodies (table 2). csf abnormalities were most pronounced on day 5 (table 1), after which time csf cell counts decreased rapidly. all cultures of blood, urine, csf, and respiratory secretions were negative for mvev. a broad investigation into possible etiologies was conducted for blood, saliva, csf, brain tissue, and respiratory samples (table 2). bal, bronchoalveolar lavage ; lul, left upper lobe ; mvev, murray valley encephalitis virus ; nd, not determined : rml, right middle lobe ; rt - pcr, reverse transcription pcr. mvev igm elisa positive, mvev igg elisa negative, and mvev plaque - reduction neutralization test negative (centers for disease control and prevention, fort collins, co, usa)., toronto, ontario, canada), which tests for respiratory syncytial virus ; human coronaviruses hku1, oc43, nl63, and 229e ; parainfluenza viruses 1, 2, 3, and 4 ; enteroviruses / rhinoviruses ; human metapneumovirus ; adenovirus ; and influenza viruses a and b. # pan - flavivirus rt - pcr and sequencing of amplicon (3). mvev was isolated on vero cells from fresh homogenates of biopsy specimens prepared at the time of autopsy on day of clinical illness. during the ensuing 2 days, decerebrate posturing worsened, rigidity increased, and the patient became deeply comatose. continuous electroencephalography monitoring showed onset of progressively worsening seizure activity refractory to phenytoin and levetiracetam. infusions of intravenous diprivan and midazolam were required to produce burst - suppression (technical appendix figure 1). on day 8, a ct scan of the brain showed marked thalamic hypodensity with sulcal effacement, acute obstructive hydrocephalus, and cerebellar tonsillar herniation (figure 1, panel c). an emergent external ventricular drain was placed, and standard measures were taken to treat intracranial hypertension. despite intervention, refractory intracranial hypertension developed (intracerebral pressure > 70 mm h2o). a decompressive craniectomy was considered but the patient died on day 10 of worsening obstructive hydrocephalus (figure 1, panel d) and cerebellar tonsillar herniation. postmortem brain biopsy specimens from the corpus callosum, upper spinal cord, and thalamus were positive for mvev by reverse transcription pcr (technical appendix figure 2) with amplicon sequences identical to those obtained from csf. mvev was readily isolated on vero cells from fresh homogenates prepared from each of the 3 biopsy specimens. additional autopsy findings included lymphocytic myocarditis, pulmonary edema, and acute tubular necrosis of the kidney. hematoxylin and eosin stained autopsy specimens from a patient with a fatal infection of murray valley encephalitis virus imported from australia to canada, 2011. b) thalamus showing extensive inflammation (arrows) surrounding an area of rarefaction caused by necrosis (arrowheads) and neuronal loss (original magnification 10) ; inset shows a microglial nodule (original magnification 20). c) pyramidal cell layer of the hippocampus showing extensive acute neuronal death (arrows) (original magnification 4). d) cerebellum showing severe depletion of purkinje neurons and acute neuronal death (arrows and inset [original magnification 40 ]) with relative sparing of the internal granule cell layer (arrowheads) and inflammation (short arrows) (original magnification 10). e) substantia nigra showing extensive inflammation, acute neuronal death (arrows), neuronophagia (arrowhead), and gliosis (original magnification 10). historically, epidemics of mve were recognized on the eastern coast of australia ; 6 known outbreaks were documented in the early twentieth century. since the late 1970s, mvev has largely been maintained in enzootic cycles involving mosquitoes and water fowl in the northern regions of central and western australia ; there have been multiple reported epidemics (4). before the outbreak in 2011, heavy rains across australia created ideal conditions for culex annulirostris mosquitoes, the vector of mvev, thus intensifying transmission to humans throughout the country (5). a shift in the demographic pattern of mve cases toward non - aboriginal, adult workers and tourists engaged in high - risk activities for mosquito exposure was observed (1). australian states and territories routinely use mvev surveillance methods (mosquito monitoring, virus isolation from mosquitoes, sentinel chicken flocks, and climate surveillance) (6). each state and territory has its own public health response and communications strategy (1), which target tourists to various degrees. human infection with mvev is generally asymptomatic or mild with nonspecific symptoms, including headache, myalgia and, less commonly, rash. mve is estimated to occur in < 0.1% of infected persons but has a mortality rate of 15%30% and produces long - term neurologic sequelae in < 50% of survivors (79). several distinct clinical patterns of mve have been observed : encephalitis with complete recovery ; cranial nerve / brainstem involvement with tremor ; spinal cord involvement (poliomyelitis - like) ; and relentless progression to death, as seen in the patient we report (8). the presence of widespread magnetic resonance imaging abnormalities of the thalamus, midbrain, spinal cord, and cerebellum during acute illness predicted a devastating neurologic outcome (10). a novel feature of this case was the postmortem finding of viral myocarditis, which could account for early and unexpected respiratory decompensation of the patient. despite increased awareness of mve, imported cases in europe, asia, and this case serves as a cautionary reminder of other viral etiologies of encephalitis that should be considered for returning travelers, although many of these etiologies might be outside the diagnostic capability of many clinical laboratories. additional information on a fatal infection with murray valley encephalitis virus imported from australia to canada, 2011. | murray valley encephalitis virus (mvev), a flavivirus belonging to the japanese encephalitis serogroup, can cause severe clinical manifestations in humans. we report a fatal case of mvev infection in a young woman who returned from australia to canada. the differential diagnosis for travel - associated encephalitis should include mvev, particularly during outbreak years. |
glaucoma is an optic neuropathy usually associated with increased intraocular pressure (iop) that causes progressive visual field loss. this disease is one of the main causes of blindness worldwide.1 although several risk factors are associated with glaucoma onset and progression, the presence of high levels of iop is the most important risk factor and the only one that can be changed.2 reduction of iop is the most efficient and clinically accepted therapy to avoid deterioration of optic disc and progression of visual loss.3 fortunately, topical medications for lowering iop have shown good efficacy and safety in glaucoma and ocular hypertension patients.4 there are five categories of topically administered medications available for the treatment of glaucoma, ie, cholinergic agents, adrenergic agonists, carbonic anhydrase inhibitors, -adrenoceptor antagonists, and prostaglandin analogs (pgas).6,7 pgas and -adrenoceptor antagonists are the most frequently used topical medications for reducing iop in patients with glaucoma.8 moreover, pgas are the most effective drugs to reduce iop, with fewer systemic side effects, and requiring only a single drop daily. currently, the pgas have been found to be more effective than -blockers in the reduction of iop in patients with glaucoma and ocular hypertension.9,10 travoprost acid, the biologically active form of travoprost, is a prostaglandin f2a analog and a fully selective agonist to the prostaglandin f receptor.1114 this receptor is abundant in the longitudinal ciliary muscle and iris sphincter of the human eye.11,13 pgas reduce iop by increasing the outflow of aqueous humor through the uveoscleral pathway.15,16 however, if treatment with monotherapy fails to reduce or maintain iop under control, a fixed combination can be an alternative to keep daily single - drop therapy.4 combining drugs that have different modes of action should provide an additional iop lowering effect.11,16 it is known that inadequate compliance with glaucoma therapy is a risk factor for progression of the disease and blindness. several guidelines indicate that adequate glaucoma therapy requires a high level of compliance and this can be better achieved with lower frequency of use of ocular medications. 7 the ocular hypertension treatment study found that, after five years of therapy, about 40% of patients required two or more medications to control iop from baseline of 20% and a final iop of < 24 mmhg. a number of studies have found poor compliance in more than one - third of patients with glaucoma (depending on the therapy used),2 and compliance is further compromised by increasing age.4 rossi used an electronic device, ie, the travatan dosing aid, in a six - month cohort study to assess adherence in glaucoma patients under travoprost or travoprost - timolol therapy. even with single - drop therapy, only 30.3% of patients had perfect adherence. the major causes of noncompliance were advancing age and duration of therapy.5 in this scenario, a fixed combination administered once daily may offer better and more convenient treatment for patients with glaucoma or ocular hypertension than the concomitant administration of two medications.4,16 usually, medical therapy is the first - choice procedure to treat primary open - angle glaucoma and some patients with ocular hypertension.17 however, when medical therapy with topical agents fails to lower iop, laser and more invasive surgical procedures are needed to reduce the risk of progressive visual field loss in patients with initial or advanced primary open - angle glaucoma and the development of a defect in patients with ocular hypertension.2,3,18 travoprost has been compared with several drugs, especially timolol and fixed combinations of timolol. this kind of comparison has an important clinical impact because of the widespread use of timolol and timolol fixed combinations worldwide. goldberg randomized 573 patients with open - angle glaucoma or ocular hypertension to treatment with two different concentrations of travoprost, ie, 0.0015% and 0.004% once daily or to treatment with timolol maleate 0.5%. the enrolled subjects had untreated iop of at least 24 mmhg, with a mean iop among all subjects of approximately 26 mmhg. after nine months of treatment, mean iop averaged across six study visits was lower with travoprost 0.004% than with timolol 0.5% at all time points. mean iop reductions ranged from 8.0 to 8.9 mmhg with travoprost 0.004% versus 6.3 to mmhg with timolol 0.5%.10 figueiredo compared iop reduction and the effect on ocular blood flow between travoprost, latanoprost, bimatoprost, and unoprostone in 92 patients with open - angle glaucoma or ocular hypertension without previous treatment. after three months, travoprost and bimatoprost showed a similar 7.2 mmhg iop reduction, whereas latanoprost and unoprostone showed 6.9 mmhg and 1.6 mmhg reductions, respectively. it was shown that travoprost could also increase pulsatile ocular blood flow.19 parrish compared three pgas head - to - head in a randomized, 12-week prospective trial including 410 subjects. this group reported no differences in mean iop reduction between travoprost (8.0 mmhg), latanoprost (8.7 mmhg), and bimatoprost (8.6 mmhg, p = 0.128).20 in another study, cantor compared the efficiency of travoprost and bimatoprost treatment in 157 patients over six months at different time points. the mean iop reductions with travoprost and bimatoprost were, respectively, 5.7 versus 7.1 mmhg at 9 am (p = 0.014), 5.2 versus 5.9 mmhg at 1 pm (p = 0.213), and 4.5 versus 5.3 mmhg at 4 pm (p = 0.207). iop reductions 20% and 30% were achieved by statistically similar proportions of patients as revealed by responder analysis, and both groups presented statistically equivalent investigator - determined clinical success which was based on drug tolerability and achievement of target iop.21 franks studied the iop - lowering response of patients with open - angle glaucoma or ocular hypertension treated with travoprost and a fixed combination of latanoprost 0.005% and timolol 0.5%. in this study, 110 subjects were randomized to receive either travoprost once daily in the evening or latanoprosttimolol once daily in the morning and, depending on randomization, masking was achieved by use of a placebo in the morning. iop reduction between the two groups showed no statistically significant difference at any time point in the study. travoprost lowered iop by 7.0 mmhg and latanoprosttimolol by 6.4 mmhg in the morning and, at the end of the day, iop reductions were 6.8 and 6.1 mmhg, respectively.11 suzuki jr compared travoprost and the fixed combination of dorzolamide 2% and timolol 0.5% on relative iop reduction. in a study that was masked to investigators but not to subjects, 56 patients with open - angle glaucoma or ocular hypertension were randomized to receive either travoprost once daily in the evening or dorzolamide - timolol twice daily. a statistically significant lower mean iop was observed with travoprost than with dorzolamide - timolol (p < 0.01) across all visits and time points. the mean iop with travoprost ranged from 7.1 to 7.5 mmhg, compared with 4.5 to 4.8 mmhg with dorzolamide - timolol at three and six weeks. in addition, more complaints were reported by patients in the dorzolamide - timolol group.22 in conclusion, the most relevant studies comparing travoprost with other drugs showed similar iop reductions with travoprost and with latanoprost or bimatoprost. moreover, travoprost showed similar or superior results when compared with fixed combinations of timolol with either latanoprost or dorzolamide. because circadian iop variability has emerged as an independent risk factor for the progression of glaucoma, the circadian iop - lowering profiles of medications have become a relevant measure of their clinical efficacy.23,24 considering this, the endurance of travoprost s iop effect periods ranging from 24 to 84 hours postdose have been evaluated by several studies.16,17 orzalesi compared the 24-hour iop - lowering profiles of travoprost, latanoprost, and bimatoprost in a crossover study. sequential treatment with each of the three drugs for one month (with a one - month washout between each treatment) was given to 44 subjects with primary open - angle glaucoma or ocular hypertension. the patients had 24-hour iop assessments at baseline and at the end of each month - long treatment session. the mean circadian iop (measured in the sitting position using goldmann applanation tonometry) between the three drugs showed no statistically significant difference. mean circadian iop reduction of travoprost was 7.1 mmhg, compared with 6.7 mmhg for latanoprost and 7.9 mmhg for bimatoprost (p = 0.08). knowing that supine iop is generally higher than sitting iop, another relevant aspect of a drug s iop - lowering profile is the ability to lower iop in the supine position, ie, while asleep at night). in order to measure supine iop they also used an electronic tonometer, and no differences in circadian iop reduction between the three drugs were observed.25 garcia - feijoo undertook a prospective, randomized, double - masked trial to compare the duration of action of travoprost and latanoprost in 62 patients with primary open - angle glaucoma or ocular hypertension. during 14 days, the patients received once - daily treatment at 8 pm, and then sitting and supine iop assessments using perkins tonometry were made every four hours out to 48 hours after drug administration. in the first and second 24-hour periods after the last dose, the mean iops produced by travoprost in the sitting position were lower than for latanoprost, but this was not statistically significant. on the other hand, iop was significantly lower in the travoprost group at every iop measurement for 12, 16, 20, 24, 36, 40, and 48 hours after the last dose in the supine position. mean travoprost iops from the periods 024, 2448, and 048 hours postdosing were lower than for latanoprost in the supine position (p < 0.05).26 taking these studies together, it becomes clear that the duration of action of travoprost exceeds its 24-hour dosing period, and that reductions from baseline are seen up to 63 hours after the last dose. at the end of each dosing period, travoprost, which is labeled for dosing once daily in the evening, has been shown to provide better iop control when compared with latanoprost.16,25,26 almost one half of glaucoma patients on topical treatment require more than one drug to control iop, and patient compliance with glaucoma treatment is clearly affected when multiple drops are needed. fixed combinations can be an alternative to maintain adequate iop control and improve compliance.16,22 schuman in a prospective, randomized, double - masked, multicenter trial compared a fixed combination once daily in the morning with concomitant therapy using travoprost once daily in the evening and timolol twice daily in 403 subjects with open - angle glaucoma or ocular hypertension during three months. the results showed that at every visit and time point, the iop - lowering from baseline was greater with the fixed combination than with timolol monotherapy. on the other hand, significantly better iop reduction from baseline at two of nine time points was observed with concomitant dosing of the separate components, while equivalent reductions were observed at the remaining seven time points. iop reductions for the fixed combination, travoprost and timolol concomitant therapy, and timolol from baseline measured across the visits and time points were 6.88.6 mmhg, 7.38.4 mmhg and 4.67.0 mmhg, respectively.27 in another prospective, randomized, multicenter, double - masked trial, hughes also compared the fixed combination dose once daily in the morning with the concomitant administration of travoprost once daily in the evening and timolol once daily in the morning in 316 subjects with open - angle glaucoma or ocular hypertension over three months. they found that at most time points the fixed combination was not inferior to concomitant dosing, inasmuch as at seven of nine time points, the upper 95% confidence limit for the difference in mean iop between the two treatment groups was within 1.5 mmhg. the two time points that were an exception to this both occurred in the morning and on separate visits. the fixed - combination iop reductions from baseline were 7.49.4 mmhg and for travoprost and timolol concomitant therapy were 8.49.4 mmhg.28 it can be concluded from these studies that there is better efficiency with concomitant therapy rather than with the combination at several time points. the different dosing protocols, in which the prostaglandin is given in the morning in the fixed combination group and in the evening in the concomitant group, might influence this finding because evening dosing of prostaglandins rather than morning dosing is generally recommended. therefore, the occasional transient conjunctival hyperemia that follows topical dosing tends to have lesser clinical significance. in contrast, because of the natural reduction of aqueous humor production at night, beta - blockers are more effective for lowering iop with morning dosing rather than with evening dosing. therefore, the fixed combination with timolol could have better performance as a result of the morning dosing.16,29,30 in order to understand better the efficacy of the travoprost - timolol fixed combination when dosed in the morning versus evening, denis evaluated 92 subjects with open - angle glaucoma or ocular hypertension in a prospective, randomized, double - masked trial. the fixed combination either in the morning or in the evening was given to patients for six weeks. the results were similar in the morning group and in the evening group, and their iop reductions ranged from 16.5 to 16.7 mmhg and from 16.1 to 17.2 mmhg, respectively. the 810 mmhg (32%38%) iop reductions from baseline of were statistically significant and clinically relevant in both groups.31 pfeiffer assessed the safety and efficacy of changing to the travoprost - timolol fixed combination from other monotherapies or adjunctive therapies in 472 patients with uncontrolled or below - target glaucoma therapy. after three months, the travoprost - timolol fixed combination reduced iop from the level prior to treatment by 5.6 (2.6) mmhg. ocular hyperemia was the most frequent adverse effect (n = 21, 4%). both patients and physicians the effects of adding topical carbonic anhydrase inhibitors or topical alpha - agonists to pgas remains little explored.33 it has been shown that dorzolamide is more effective than timolol or brimonidine 0.2% as adjunctive therapy for lowering iop in eyes already on latanoprost.34 in another double - masked crossover trial, konstas could not find any difference in 24-hour iop measurements between adjunctive dorzolamide twice daily and brimonidine 0.15% twice daily in combination with latanoprost after six weeks of adjunctive therapy. four weeks later, the mean iop of the 78 patients under treatment with a combination of travoprost and brinzolamide was 18.5 (1224) mmhg. finally, 12 weeks later, the mean iop for 71 evaluable patients was 18.2 (1027) mmhg. at all time points, iop was significantly reduced when compared with baseline values (p < 0.0001). the average iop had decreased by 3.9 mmhg (17.4%) after four (n = 78) and by 4.2 mmhg (18.4%) after 12 (n = 71) weeks of combined travoprost and brinzolamide therapy when compared with the monotherapy baseline of travoprost ophthalmic solution 0.004%. after four weeks of adjunctive treatment, 56% of patients (n = 78) and 63% of patients after 12 weeks (n = 71) had at least an additional 15% reduction in iop.35 reis randomized 52 eyes with open - angle glaucoma or ocular hypertension to receive adjunctive therapy of timolol 0.5%, brinzolamide 1%, or brimonidine tartrate 0.2% in conjunction with travoprost. brinzolamide 1% and timolol maleate 0.5% showed greater iop reduction compared with brimonidine 0.2%.36 the advantages of simpler dosing for topical glaucoma therapy can be better noticed in a regular daily - life environment than in clinical studies. this might be due to the fact that single - drop therapy is simple and flexible for patients, as well as the absence of the washout effect present with multiple - drop therapies. moreover, maintenance of short - and long - term adherence to glaucoma medication regimens is better with a once - daily travoprost - timolol combination rather than with multiple - drop therapy. as reported by covert, 30.2% of patients treated with latanoprost 0.005% and 23.2% treated with bimatoprost 0.03% required adjunctive treatment. travoprost accounted for 22.5% of the adjunctive therapy.37 netland reported that only 8% of patients treated with travoprost 0.004% needed adjunctive treatment.9 in studies to evaluate the relative incidence of hyperemia between prostaglandins, netland found that the incidence of hyperemia caused by latanoprost was 27.6%, while travoprost had a rate of 49.5%, and cantor observed hyperemia in 21.1% of eyes treated with bimatoprost and in 14.8% in eyes treated with travoprost.9,21 the use of travoprost 0.004% induced a conjunctival hyperemia incidence of 32.5%49.5%, whereas timolol maleate 0.5% treatment had an incidence of 7%14%.16 hyperemia is usually mild and unlikely to interrupt clinical studies. in fact, improvement of hyperemia during continued dosing has been reported.10 parrish found a higher incidence of hyperemia for bimatoprost, ie, 68.6%. travoprost and latanoprost had a hyperemia incidence of 58% and 47.1%, respectively.20 it must be taken in consideration that the use of different methods for evaluation of hyperemia might be the cause of the significant variation of reported rates for conjunctival hyperemia, even for individual drugs. these methods have included patient complaints, tiered scoring systems used for subjective investigator grading of hyperemia, as well as photographic evaluation. apart from the aesthetic adverse effects, pgas can also induce darkening of the iris, and its incidence in the literature varies according to the different methods used in its evaluation. netland reported that iris hyperpigmentation was observed in 5.2% of eyes treated with latanoprost and in 3.1% in eyes treated with travoprost. another study by cantor in 157 subjects compared the effects of travoprost and bimatoprost, and iris hyperpigmentation developed in a single bimatoprost - treated eye.9,21 because of the fact that green and mixed hazel eyes are most affected by iris hyperpigmentation, the baseline eye color might influence the risk of developing this adverse effect. it was shown in a five - year study by alm that over 75% of green - brown or yellow - brown eyes suffered iris hyperpigmentation after latanoprost treatment, while brown or blue / grey eyes were not affected.38 overall, the incidence of iris hyperpigmentation caused by one year of daily treatment with travoprost 0.004% is low (less than 5%), and is considered to be a cosmetic issue rather than a harmful adverse effect with regard to either vision or health.16,38 the eyelashes can suffer some changes during treatment with travoprost and other pgas. these drugs can induce eyelashes to increase in number and can cause alteration in their length, thickness, and darkness.16 a new preservative for travoprost, sofzia (alcon laboratories, fort worth, tx, usa), seems to offer better tolerability than benzalkonium chloride (bak) for patients with ocular surface complaints. bak - free travoprost was compared with latanoprost containing bak preservative in patients with superficial punctate keratopathy. after replacing latanoprost containing bak with travoprost containing sofzia, the score for superficial punctate keratopathy decreased significantly three months later.39,40 the integrity of the blood - aqueous barrier after prostaglandin treatment has been evaluated by cellini. cell and flare values of the anterior chamber were measured in 60 glaucoma patients who were randomly assigned to receive travoprost, latanoprost, or bimatoprost. a flare meter was used to quantify both cell and flare at baseline and after three and six months of therapy. the results showed significant increases in cell and flare from baseline at three and six months, and slight diminution of cell flare between three and six months of therapy for all three drugs, whereas significantly more cell and flare were induced by latanoprost at three and six months. after three months of therapy, travoprost induced more cell and flare than bimatoprost, and no significant difference between these two drugs was observed at six months.41 similarly, in a crossover design, arcieri studied the effect of these drugs in 34 phakic individuals. the patients received travoprost, latanoprost, and bimatoprost for four weeks, with a four - week washout between each drug. the drugs did not increase anterior chamber flare, nor did they induce differences in flare levels in a drug - dependent manner.42 the use of all three pgas has been associated with macular edema, even though other risk factors for macular edema were already present, and usually prior to both complicated and uncomplicated cataract surgery. its incidence is higher in pseudophakic eyes, and in eyes with other risk factors for macular edema, while probably no risk of macular edema can be implicated in phakic eyes without risk factors. macular edema, as well as impaired visual acuity, can be resolved with interruption of pga treatment.4346 notably, the cardiovascular and pulmonary systems, and blood and urine are not considerably affected by travoprost treatment.16 iop reduction is efficiently achieved by the pgas. among them, travoprost can lower iop levels to 6.59.0 mmhg, being as effective as products combining timolol with latanoprost or dorzolamide. other benefits of travoprost include probable increased efficacy in black patients, eyes with pseudoexfoliation, eyes with chronic angle - closure glaucoma, and following cataract surgery. even though the recommended dosing is once daily, travoprost can lower iop up to 63 hours after the last dose, demonstrating greater iop control at the end of each dose compared with latanoprost. despite the development of minor adverse effects, such as conjunctival hyperemia, iris and eyelid hyperpigmentation, eyelash changes, and other rare cases of iritis and macular edema, which are common to pga therapy, the efficiency and safety of travoprost have been extensively demonstrated. moreover, convenient once - daily dosing has made travoprost a first - line therapy for glaucoma treatment and, in fixed combination with timolol, an option to enhance iop control when monotherapy fails. | travoprost is a prostaglandin analog used in the management of glaucoma and ocular hypertension for reducing intraocular pressure (iop). the iop - lowering efficacy of travoprost has been shown to be similar to that of other prostaglandins, including latanoprost and bimatoprost. when compared with fixed combinations of timolol and either latanoprost or dorzolamide, travoprost alone can reduce mean iop in a similar or superior manner. concomitant therapy of travoprost and timolol can reach even greater iop reductions than fixed combinations at some time points, but with no difference in the early morning, when iop is usually higher. in addition, the long duration of action of travoprost can also provide better control of iop fluctuation, probably due to its stronger prostaglandin f receptor mechanism. the side effects of travoprost do not represent a risk to the vision or health of the patient. the proven efficacy and safety combined with convenient once - daily dosing for travoprost increases patient compliance with treatment for glaucoma. |
a venous ulcer is a break in the continuity of the skin resulting from venous hypertension (figure 1). this is the most common cause of leg ulceration in the united kingdom with a prevalence of 1.53 per 1000, increasing to 20 per 1000 in patients over 80 years old. this presents significant disease burden to the united kingdom national health service with an estimated cost of 300 million / year. therefore, both therapeutic efficacy and cost - effectiveness should be taken into account when creating evidence - based management plans. incompetent valves in either the superficial venous system or the perforator veins result in chronic venous hypertension followed by ulceration. fibrin cuff hypothesis proposed that venous hypertension causes fibrinogen to leak out and build up around the vessel preventing oxygen and nutrients from reaching the cells. this was followed by the leucocyte trapping theory, which attributes tissue damage to trapped white cells releasing proteolytic enzymes and oxygen free radicals. the latest theory suggests chronic inflammation due to repetitive ischaemia - reperfusion as the primary mechanism of cellular damage and wound formation. regardless of the exact pathogenesis, treatment involves reversing the venous hypertension causing the ulcer. venous disease of the lower legs can be classified using clinical severity, aetiology, anatomy, and pathophysiology (ceaf classification system). the role of doppler ultrasound in evaluating venous disease according to the ceaf classification has demonstrated very low intraobserver variability and a high sensitivity and specificity. patients with an open venous ulcer are already classified as having the most clinically severe form of venous disease (c6 classification). conservative management of venous ulcers involves elevating the legs and wearing graduated compression stockings to reduce venous stasis and oedema. a 40 mmhg compression at the ankle has been found to be most effective. four layered bandages increase the chance of healing by 30% compared to short stretch bandages. dressings for venous ulcers are chosen on the basis of ability to absorb fluid and odour, adhesiveness, antibacterial and haemostatic properties, potential to cause sensitivity reactions, ease of handling, tendency to shed fibres, and interval required between dressing changes. silver, iodine, or honey based dressings have increased antimicrobial activity and hydrocolloids increase the moisture content of the wound. whether these dressings actually do promote faster wound healing by the above mechanisms is up for debate. a trial of this nature has not been done at university hospital of south manchester leg ulcer clinic. a retrospective comparison was made to assess differences in efficacy and cost - effectiveness between simple nonadhesive ultra dressings (e.g., na ultra) and modern dressings. there is no significant difference in leg ulcer healing rates when comparing simple nonadherent ultra dressings with modern dressings such as inadine, iodoflex, medihoney, aquacel ag, and atrauman ag. patients with an ankle brachial pressure index (abpi) < 0.8 or a history of deep vein thrombosis, diabetes mellitus, inability to move, or mental health problems were excluded. records that did not satisfy the inclusion criteria were eliminated leaving a total of 24 patients. twelve were treated with simple nonadherent ultra dressings and the rest were treated with an array of different dressings including silver based dressings such as atrauman ag and aquacel ag, iodine based dressings such as iodoflex and inadine, and the honey based medihoney dressing. according to medical records all venous ulcer patients underwent a complete history and examination. the wound was assessed for slough, granulation, epithelialisation, and level of exudate. the surrounding skin was assessed for dryness, eczema, and haemosiderin pigmentation. the calf and ankle circumference were measured and appropriate compression therapy started. the ulcer area was calculated every week by tracing the ulcer on graph paper and counting the squares. pictures were taken to keep a visual record of the healing process and the percentage of granulation tissue was noted. the time taken to complete healing, defined as 100% epithelialisation of the wound, for some patients data was lacking and the time to complete healing could not be determined. in these patients the time period between two measured ulcer areas was taken and the healing rate was calculated as change in area / time taken for that change in cm / week. the unpaired student 's t - test was applied to determine significance assuming an equal variance between both groups. the cost of dressings for treatment was also measured by multiplying the total area of dressing used for the treatment period by the cost of dressing per unit area. the nhs supply line prices were estimated to be 50% of the market price based on knowledge of the price of inadine in both the market and nhs supply line. the market price was standardised as the price at http://dressingsonline.com/. the area of dressing used was calculated by multiplying the initial ulcer area with the number of dressings changed until the ulcer healed. the average cost of dressings during the treatment period and the standard deviation were calculated for both groups. the unpaired student 's t - test was applied to determine significance assuming an equal variance in both groups. cohen 's d and the effect size r were also calculated to evaluate the strength of difference. the average cost of dressings per patient was used to calculate the annual cost of dressings of both types. there were 6 males and 6 females in the simple nonadherent ultra group compared to 2 males and 10 females in the other group. the average age was 68.67 years for the simple nonadherent group compared with an average age of 71.5 years in the other group seven were from the simple nonadherent ultra dressing group and 11 were from the group containing other dressing types. the data available was not sufficient to determine if the remaining 6 patients ' ulcers completely healed. the healing rate was usually less than 1 cm per week and more than 0.1 cm per week independent of the type of dressing used. there are anomalies in both groups where ulcer healing rate exceeds 1 cm per week. in the simple nonadhesive ultra dressing group there is an anomalous decreased value for the healing rate equal to 0.02 cm per week. it is possible that these anomalies resulted from factors other than the type of dressing used such as the duration of the ulcer, the type of compression therapy, or patient compliance. the mean healing rate for simple nonadherent ultra dressings is 0.353 cm per week with a standard deviation of 0.3185 (table 1). this is less than the mean healing rate for other dressing types calculated to be 0.415 cm per week with a standard deviation of 0.383 (table 2). the unpaired student 's t - test was applied to determine the significance of this difference with 22 degrees of freedom. this resulted in a one - tailed p value of 0.336 and a two - tailed p value of 0.672, indicating that the difference in ulcer healing between the two groups is not statistically significant (table 3). a multiple regression analysis was also performed to validate the data (table 4). this gave a significance f value of 0.8134 with the coefficient of determination r = 0.0058. this supports the findings of student 's t - test suggesting no significant difference in venous ulcer healing rates. total costs of simple nonadherent ultra dressings range from 0.009 to 3.82, while modern dressings range from less than 0.2 to more than 8, increasing with initial ulcer area and duration of treatment. the mean cost of dressing using nonadherent ultra is 0.702 with a standard deviation of 1.08 (table 1) compared with a mean cost of 4.78 and a standard deviation of 4.816 using other dressings (table 2). this gives a one - tailed p value of 0.0045 on application of student 's t - test (table 3). cohen 's d is 1.17 and the effect size r is calculated to be 0.5 which is conventionally classed as medium. an estimated 100000 per year can be saved by treating 25000 patients with simple nonadherent dressings instead of other more expensive dressings (table 5). many prospective randomised controlled trials have compared modern dressings with simple nonadhesive dressings, for example, na ultra. a meta - analysis published in wound repair and regeneration evaluated 31 studies comparing polyurethane, activated charcoal, alginates, hydrocolloids, and collagen dressings with conventional dressings and found no significant differences in wound healing. another meta - analysis published in bmj evaluated 42 randomised trials to determine the efficacy of hydrocolloids, hydrogels, alginates, and foams. there was no significant difference in healing when hydrocolloids and simple dressings were compared, but there was not enough data to draw strong conclusions for other dressing types. another systematic review found that semiocclusive dressings such as foam, film, cellulose, alginate, and hyaluronic acid derived dressings were not more effective than simple low adherent dressings in improving healing rates in venous ulcer patients. it also found no statistical differences in the proportion of ulcers healed with silver based dressings compared to dressings not containing silver. this study supplements these trials by providing a comparison of ulcer healing rates with different dressings in the greater manchester patient population. ulcer healing is a complex and dynamic process that includes clotting, inflammation, granulation tissue formation, epithelialisation, neovascularisation, collagen synthesis, and wound contraction. the ideal environment for wound healing is adequately oxygenated, warm, and moist and is free from infection or necrotic tissue. the results indicate that leg ulcer healing rates do not significantly vary depending on the type of dressing used while significant savings in cost can be made by the increased use of simple nonadherent ultra dressings. in the current economic climate this requires healthcare practitioners to identify where cuts can be made without affecting patient care. the use of modern dressings is one such area as all available evidence suggests that the cheaper simple nonadhesive dressings work just as well. this is supported by the vulcan randomised controlled trial which found that silver impregnated dressings have an incremental cost of 97.85 compared to simple dressings without significantly improving healing rates. cost of dressing shows wide variation. however, estimated yearly savings of more than 200000 can be made if 50000 leg ulcer patients per year are treated with na ultra dressings instead of modern expensive dressings (table 5). small changes in the price of dressings can cause large differences in the total cost as it is dependent on duration of treatment and ulcer size as well. of note, the ulcer area is generally greater in the modern dressings group resulting in greater mean cost. it is assumed that the same area of dressing is used at each follow - up visit. in reality, the area of dressing used is likely to be less each week as some ulcer healing would have taken place. this is countered by the assumption that all of the dressing area was used to cover the ulcer without any waste. this likely overcompensates for the initial assumption resulting in an underestimate of the dressing costs and yearly savings. this was done for the sake of simplicity as consistent application of the same formula would not affect the comparison in costs between both groups most major factors affecting wound healing (table 6) were controlled through the exclusion criteria. however, important confounding factors that were not controlled include bmi, ulcer duration, type of compression therapy, patient compliance, smoking and alcohol intake, and wound infection. nonetheless, the two groups are still comparable given that these factors are likely evenly distributed amongst both groups. since this is a retrospective study, ulcer area calculation and management were not biased by the motives of the research decreasing the likelihood of confounding due to different treatments. however, the retrospective nature of the study does open itself to bias in data selection and misclassification. to minimize this, selection of patient records was randomized by asking an individual not involved in the research to hand over the patient records once the exclusion criteria had been satisfied. the use of different comparators for the modern dressings group may also make the comparison unfair. it is possible that one of the many modern dressings is significantly better than simple dressings while another is significantly worse making the cumulative effect negligible. however, given that all the modern dressings are antimicrobial in nature we can reasonably treat them as a single group and compare them collectively. the lack of patients treated with a particular type of dressing makes individual comparison difficult even though such a comparison would be ideal. the small sample size (n = 24) is a limitation shared by previous studies on this subject. this is difficult to overcome unless a similar study is repeated with a much larger patient population covering many different clinical sites. most venous ulcer patients have multiple comorbid conditions and thus need to be excluded from studies to avoid confounding factors. this is the most clinically severe form of venous disease (c6 classification) which would give the largest scope for improvement. however, if effect size is indeed small then it would not be cost - effective to use very expensive dressings for potentially little benefit. based on these results it is not altogether clear if a large scale randomised controlled trial to determine efficacy and cost - effectiveness of dressings is warranted. all studies undertaken so far have been consistent in concluding that healing rates do not depend on type of dressing there is also a tendency to intuitively think antimicrobial dressings or moisture enhancing dressings would improve healing rates given that infection and dryness impair healing. this is coupled with anecdotal evidence and individual claims that modern dressings work and simple dressings do not. a cost - benefit analysis is suggested for a large scale prospective study comparing specific dressings in uncomplicated venous ulcer patients.. the cost of dressing should be the primary factor influencing dressing selection unless the patient prefers a particular dressing. patients should be informed that there is no conclusive evidence that modern dressings provide superior wound healing. | objective. to compare the efficacy and cost - effectiveness of simple nonadherent dressings with other more expensive dressing types in the treatment of venous leg ulcers. study design. retrospective cohort study. location. the leg ulcer clinic at the university hospital of south manchester. subjects and methods. the healing rates of twelve leg ulcer patients treated with simple nonadherent dressings (e.g., na ultra) were compared with an equal number of patients treated with modern dressings to determine differences in healing rates and cost. main outcome measures. rate of healing as determined by reduction in ulcer area over a specified period of time and total cost of dressing per patient. results. simple nonadherent dressings had a mean healing rate of 0.353 cm2/week (standard deviation 0.319) compared with a mean of 0.415 cm2/week (standard deviation 0.383) for more expensive dressings. this resulted in a one - tailed p value of 0.251 and a two - tailed p value of 0.508. multiple regression analysis gave a significance f of 0.8134. conclusion. the results indicate that the difference in healing rate between simple and modern dressings is not statistically significant. therefore, the cost of dressing type should be an important factor influencing dressing selection. |
the primary goal of periodontal treatment is the maintenance of the natural dentition in health and comfortable function. when periodontal disease has caused a loss of the attachment apparatus, optimal care seeks to regenerate the periodontium to its predisease state. complete and predictable restoration of the periodontium following trauma or infection remains a critical objective in periodontics and bone replacement grafts remain among the most widely used therapeutic strategies for the correction of periodontal osseous defects. to preserve the interdental soft tissue for maximum soft tissue coverage following surgical intervention involving the treatment of proximal osseous defects, takei. later cortellini. gave modifications of the flap design modified papilla preservation flap and simplified papilla preservation flap to be used in combination with regenerative procedures. the whale 's tail technique, which was designed for the treatment of wide intrabony defects in the esthetic zone. this technique involved the elevation of a large flap from the buccal to the palatal side to facilitate access and visualization of the intrabony defect and was created, especially to perform regeneration while maintaining interdental tissue over grafting material. the aim of our study is to assess the clinical efficacy of this new surgical technique three systemically healthy subjects with probing depths 67 mm and radiographic evidence of bone loss in relation to the maxillary anterior teeth were included in the study. probing depths and attachment loss were recorded, and complete scaling and root planing were done for all the subjects. preoperative probing depth incision points were marked [figure 2 ], and two vertical full - thickness incisions were traced from the mucogingival line to the distal margin of the tooth neighboring the defect on the buccal surface. a horizontal incision whale 's tail - shaped incision joined the apical margins of the first two incisions, and the coronal margins of the vertical incision were continued intrasulcularly in the buccal, interproximal, and palatal aspects of the defect - associated tooth [figure 3 ]. a full thickness mucoperiosteal flap was reflected from the buccal to the palatal side following which complete removal of granulation tissue and scaling and root planing was done [figure 4 ]. bone graft (perioglas) was placed in the intrabony defect, [figure 5 ] following which flap was repositioned from the palatal to buccal [figure 6 ]. 4 - 0 ethicon, nonresorbable, perimeter sutures were placed, without tension, away from the margins [figure 7 ]. postoperative instructions were given, and the patient was asked to use 0.2% chlorhexidine mouth rinse 48 h after the procedure for a period of 2 weeks. the subjects were recalled after 2 weeks for suture removal and were recalled after the duration of 3 months and 6 months [figure 9 ]. subjects 2 and 3 were treated similarly and per - operative and post - operative probing depths were recorded [figures 1015 ]. whale 's tail incision placed flap reflected from buccal to palatal aspect with intrabony defect with relation to 11 debridement done and bone graft placed perimeter sutures placed away from incision lines six months postoperatively preoperative probing depth = 7 mm (subject 2) postoperative probing depth = 3 mm (subject 2) preoperative probing depth = 7 mm (subject 3) postoperative probing depth = 3 mm with recession (subject 3) three systemically healthy subjects with probing depths 67 mm and radiographic evidence of bone loss in relation to the maxillary anterior teeth were included in the study. probing depths and attachment loss were recorded, and complete scaling and root planing were done for all the subjects. incision points were marked [figure 2 ], and two vertical full - thickness incisions were traced from the mucogingival line to the distal margin of the tooth neighboring the defect on the buccal surface. a horizontal incision whale 's tail - shaped incision joined the apical margins of the first two incisions, and the coronal margins of the vertical incision were continued intrasulcularly in the buccal, interproximal, and palatal aspects of the defect - associated tooth [figure 3 ]. a full thickness mucoperiosteal flap was reflected from the buccal to the palatal side following which complete removal of granulation tissue and scaling and root planing was done [figure 4 ]. bone graft (perioglas) was placed in the intrabony defect, [figure 5 ] following which flap was repositioned from the palatal to buccal [figure 6 ]. 4 - 0 ethicon, nonresorbable, perimeter sutures were placed, without tension, away from the margins [figure 7 ]. postoperative instructions were given, and the patient was asked to use 0.2% chlorhexidine mouth rinse 48 h after the procedure for a period of 2 weeks. the subjects were recalled after 2 weeks for suture removal and were recalled after the duration of 3 months and 6 months [figure 9 ]. subjects 2 and 3 were treated similarly and per - operative and post - operative probing depths were recorded [figures 1015 ]. whale 's tail incision placed flap reflected from buccal to palatal aspect with intrabony defect with relation to 11 debridement done and bone graft placed perimeter sutures placed away from incision lines six months postoperatively preoperative probing depth = 7 mm (subject 2) postoperative probing depth = 3 mm (subject 2) preoperative probing depth = 7 mm (subject 3) postoperative probing depth = 3 mm with recession (subject 3) following the treatment, 6 months postoperatively, patient 1 had a probing depth reduction of 3 mm and a gain in clinical attachment of 3 mm ; patient 2 had a probing depth reduction of 4 mm and a gain in attachment of 4 mm ; and patient 3 had a probing depth reduction of 4 mm and a gain in attachment of 1 mm but an increase in recession by 3 mm. the surgical technique, we used in this case series, allows regeneration of wide intrabony defects involving the maxillary anterior teeth with notable interdental diastemas, maintaining interproximal tissue to recreate a functional attachment with esthetic results. it was possible to elevate a large flap from buccal to palatal, which allowed the preservation of a large amount of soft tissue and resulted in good primary closure. besides, positioning of incisions away from the defect area and placement of sutures distant from the regenerated defects decreased the chances of bacterial colonization of the biomaterials, which is often responsible for regenerative failures. bianchi and bassetti used this technique and showed a mean probing attachment level gain of 4.9 1.8 mm and a probing pocket depth reduction of 5.8 2.5 mm. our cases showed similar results with a mean probing depth reduction of 4 mm and a mean gain in the clinical attachment of 3 mm. furthermore, the systematic use of incisions distant from the defects and biomaterial margins drastically reduced the percentage of flap dehiscence. primary closure of the interdental space after surgery and during the follow - up period was achieved in 100% of treated sites. another case report by damante. showed recession in the maxillary right central incisor. esthetic considerations always pose therapeutic dilemmas in the selection of the appropriate surgical technique in the maxillary anterior region to prevent or minimize esthetic problems such as loss of interdental papilla or increased tooth length without compromising the main goal of periodontal surgery. to overcome the disadvantage of conventional papilla preservation technique (takei.,) cortellini modified the technique by reflecting the flap from buccal to the palatal aspect (modified papilla preservation technique). a study done by retzepi., to compare the gingival blood flow during healing of simplified papilla preservation flap and modified widman flap, showed when the gingival blood flow during healing was compared between the two, the simplified papilla preservation technique may be associated with faster recovery of the gingival blood flow postoperatively. a higher gingival blood flow to different parts of the periodontium can have a positive effect on the speed and on the quality of the healing process. furthermore, an improved healing process would be of paramount importance for the final outcome of various regenerative procedures. one of the limitations of this case series is the occurrence of recession associated with subject 3 which increased postsurgically. this could be attributed to the relatively thin gingival biotype, handling of the tissue, and placement of the incision. however, the main advantages of the technique include good access to the defect area and placement of margins away from the regenerative material, which will prevent the inflammatory response near the regenerative material, thereby increasing the chances of graft uptake. furthermore, the handling of the interdental papilla is easier and more convenient than the conventional papilla preservation technique. the indications of this technique include therapies aimed at regeneration of periodontal defects such as bone grafts, membrane, or combination of these materials, surgical treatment of anterior tooth region with diastema present. | the whale 's tail technique performed to obtain maximum interdental papilla fill in the anterior region after placement of bone grafts. this study aims to assess the clinical efficacy of this new technique. this report describes a series of three cases with a probing depth of 67 mm in the maxillary anterior teeth and their treatment with whale 's tail technique to obtain regeneration and maximum papilla preservation. the cases in this report showed a pocket depth reduction of 3 - 4 mm and a clinical attachment gain of 3 - 4 mm. the application of the whale 's tail flap leads to clinically significant improvement of hard and soft tissue conditions and allows regeneration of wide intrabony defects involving the maxillary anterior teeth with notable interdental diastemas, maintaining interproximal tissue to recreate a functional attachment with esthetic results. |
ship ballast (water) is a well - recognized conveyer of nonindigenous species [15 ]. in an effort to control movements and introductions of nonindigenous species via ballast, the regulation d2 requirement to treat or decontaminate ballast water was developed from international legislation developed by the international maritime organization (imo), the international convention for the control and management of ships ballast water and sediments. regulation d2 specifies that ships constructed during and after 2009 with under 5000 m ballast water capacity are required to have treatment capability to meet the d2 standards. ballast water treatment systems must be approved within relevant imo guidelines and achieve treatment standards of : 50 m ; 99.99% reduction). the technologies to treat ballast water are typically derived from proven municipal and other industrial applications. for example, increased ph from the incorporation of lime, has been used for many years at water treatment plants as a very effective agent for the elimination of coliform bacteria from effluent waters [17,4446 ]. van arnum provided a report on the use of lime at the youngstown, oh (usa) water treatment facility to cleanse waters with a presumptive coliform bacteria index of 1.00 10 cfu/100 ml. following treatment with lime dosages that yielded approximately 10 ppm causticity (i.e., excess lime treatment ; ph not given), it was often shown that no gas - forming bacteria (e.g. coliforms) were detected after a 3.5 h detention. in another study, wattie and chambers evaluated lime as a bactericidal agent to selected enteric bacterial pathogens common in untreated water, including e. coli. pure cell suspensions of viable bacteria were added to ph - adjusted, sterilized water to initial (0 h) cell densities of approximately 1.50 10 cfu / ml. at ph 10.0110.5, 8.67 h was necessary to obtain a 100% kill at 2025 c ; whereas, 3.5 h was required at ph 11.0111.5. this temperature range that the e. coli cultures were tested, which was lower than the temperature used in the present study, would be anticipated to increase the duration of high ph exposure to achieve complete bactericidal effect. in the present study, e. coli cultures were tested at 35 c, with 100% bactericidal effect demonstrated in under 4 h with three of four isolates at ph 10.0, and for all isolates at ph 11.0. a bacterial growth medium having the ph adjusted with sodium hydroxide to ph 10.012.0 proved to be an inhospitable environment for a variety of gram - negative and gram - positive bacteria. all of the bacteria tested were affected to some extent even at the lowest ph (10.0) evaluated as shown by the reduction in viable cell counts ; ph 12.0 for 72 h was bactericidal for all isolates examined. | ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. there is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. the present study employed laboratory methods to evaluate the bactericidal efficacy of increased ph (ph 10.012.0) for exposure durations of up to 72 h to kill a variety of gram - negative and gram - positive bacteria including fish pathogens (aeromonas spp., yersinia ruckeri, edwardsiella ictaluri, serratia liquefaciens, carnobacterium sp.), other common aquatic - inhabitant bacteria (serratia marcescens, pseudomonas fluorescens, staphylococcus sp., bacillus sp.) and indicators listed in international maritime organization d2 standards ; namely, vibrio cholera (an environmental isolate from fish), escherichia coli and enterococcus faecalis. volumes of 5 n naoh were added to tryptic soy broth to obtain desired ph adjustments. viable cells were determined after 0, 4, 12, 24, 48, and 72 h. initial (0 h) cell numbers ranged from 3.40 104 cfu / ml for bacillus sp. to 2.44 107 cfu / ml for e. faecalis. the effective endpoints of ph and treatment duration necessary to realize 100% bactericidal effect varied ; however, all bacteria tested were killed within 72 h at ph 12.0 or lower. the lowest parameters examined, 4 h at ph 10.0, were bactericidal to v. cholera, e. ictaluri, three of four isolates of e. coli, and (three of four) aeromonas salmonicida subsp. salmonicida. bactericidal effect was attained at ph 10.0 within 12 h for the other a. salmonicida subsp. salmonicida, and within 24 h for p. fluorescens, and the remaining e. coli. |
mature cystic teratoma, the most common type of ovarian teratoma, is also the most common ovarian germ cell - derived neoplasm and it account for 20% of all ovarian tumors 1. endometriosis coexisting with mature cystic teratoma in the same ovary is extremely rare, although both benign conditions are said to be common in women in the reproductive age group. we report a rare case of coexistence of endometriosis and mature cystic teratoma in the same ovary combined with fimbrial ectopic pregnancy. a 28-year - old (g1p0) woman was referred to our center with a history of vaginal bleeding of 2 days duration and mild abdominal discomfort. transvaginal ultrasonography showed an enlarged uterus containing an amorphous thickened endometrium and absence of fetal parts. ultrasound revealed bilateral ovarian masses of 6 cm, respectively, and a moderate amount of intraperitoneal fluid. further evaluation with magnetic resonance imaging (mri) revealed bilateral mature cystic teratomas and irregular nodular thickened endometrium (fig.1). fibrinous material and clot adherent to the fimbrial end of the left fallopian tube were noted. after careful evacuation of fibrinous material and clot, the bleeding focus was identified in the fimbrial end of the left fallopian tube. as the bilateral tubes appeared to be unaffected by the ectopic pregnancy except for bleeding site of the left fimbrial end, the bleeding site was sutured. the removed fibrinous material and clot were sent for pathological examination and the final histology confirmed the presence of the chorionic villi, consistent with ectopic pregnancy. in addition, on histologic analysis of the bilateral ovarian masses, the diagnosis of bilateral ovarian mature cystic teratomas was confirmed and the simultaneous presence of ovarian endometriosis and mature teratoma in the left ovary was also noted (fig.2). to reduce the risk of persistent ectopic pregnancy, systemic administration of methotrexate (50 three weeks postoperatively, postoperative course was uneventful and the -hcg decreased to 32.83 miu / ml. axial t2-weighted image without fat suppresion (a) shows high signal intensity mass in both ovaries with well - defined margin. axial t1-weighted (b) images show distended endometrial cavity filled with high signal intensity fluid. on axial gadolinium - enhanced fat saturated t1-weighted image. (c) homogeneous enhancement of the uterus with some enhancing endometrial nodularity in seen. (a) tissue types present in this slide include skin, skin appendages, and adipose tissue. mature cystic teratoma is a benign, cystic lesion containing tissue from all three embryonic layers ; endoderm, mesoderm and ectoderm. mature cystic teratomas tend to occur at relatively young age in the reproductive years 2. mature cystic teratomas of the ovary are often discovered by routine physical examination, during radiographic examinations, or during abdominal surgery performed for other indications. when complications such as torsion, rupture, infection, and malignant transformation occur, these mature cystic teratomas present with discomfort, or pain 3. endometriosis is a chronic and recurrent disease characterized by the abnormal growth of the functional endometrial glands and stroma outside the uterine cavity, which occurs in 10% of women of reproductive age 4. although the most common symptoms of endometriosis are dysmenorrhea, dyspareunia, and chronic pelvic pain, many of its symptoms are of non - specific nature. there are some important aspects to consider when dealing with endometriosis and mature cystic teratoma of the ovary. although endometriosis is one of the most frequent causes of secondary infertility in young women, the association of teratoma with infertility is considered rare. microscopically, endometriosis is associated with stromal implants and reduced follicular number and activity, whereas residual ovarian cortex containing several germinal follicles is frequently found even if teratoma is bilateral and very large in size 5. in addition, the management of ovarian tumors can be challenging because of the risk of a possible malignancy. the frequency of endometriosis in malignant tumors was 11.2% and endometriosis may be closely related to ovarian tumors such as endometrioid adenocarcinoma, while mature cystic teratomas had a low risk of malignancy (0.173%) 2,6. therefore, conservative ovarian surgery in patients who desire to preserve fertility should be carefully selected based on preoperative evaluation. our literature review identifies only two of these cases, and the primary reports for one of these cases could not be retrieved from the available english literature. this one case is known only through its inclusion in a subsequent literature review and is not included in our table 1. table1 summarizes the cases of coexisting endometriosis and teratoma in a single ovary reported, including the present case. ferrario 7 decribed the first case report of this coexistence of mature teratomas and endometriosis in a single ovary, which was a coincidental finding in a 23-year - old woman who underwent a bilateral salpingo - oophorectomy for a pelvic mass. caruso and pirrelli 8 confirmed histologically the separate endometrial and teratomatous lesions in the left ovary. also, they stated that this coexistence of teratoma and endometriosis had clinical relevance because an endometriotic pathology could reveal a silent teratoma with bilateral localization 1,8. 1 decribed a case of a large ovarian tumor composed of both endometriosis and mature cystic teratoma in a 30-year - old woman. in the patients with coexistence of varied pathology in a single organ, they mentioned that emphasis must be placed on accurate clinical assessment and decisive histologic verification. summary of cases of simultaneous occurrence of endometriosis and teratoma in a single ovary reported, including the present case the presented case showed co - occurrence of two types of problems : the site of implantation of the ectopic pregnancy in the tubal fimbria and endometriosis coexisting with mature cystic teratoma of the same ovary. ectopic pregnancies are mostly located in the fallopian tubes, accounting for 98.3% of all cases. incidence of implantation in the ampulla, isthmus, fimbrial end, and interstitial (corneal) region is 79.6%, 12.3%, 6.2%, and 1.9%, respectively. also, ectopic pregnancy outside the fallopian tube ; only 1.4% of ectopic pregnancies are abdominal pregnancies, 0.15% ovary or 0.15% cervical 9. early detection of fimbrial ectopic pregnancy is often difficult because of the rarity and the asymptomatic nature before intra - abdominal hemorrhage from the fimbria occurs. however, unusual types of ectopic pregnancy such as fimbrial ectopic pregnancy are difficult to ascertain, especially with the presence of ovarian cysts as in this case. the laparoscopic approach is preferred as a safe and feasible surgery offers a short hospital stay, little or no postoperative care, and allows a swifter recovery time and the majority of ectopic pregnancies can be managed this way. the management for fimbrial ectopic pregnancy must be individualized, according to the state of the affected fallopian tube and desire for future fertility. our patient was thought that the tubal damage of fimbrial ectopic pregnancy was minimal and not significant enough to be resulted in loss of tubal function. therefore, laparoscopic suturing after removal of an ectopic pregnancy rather than salpingectomy was performed. the incidence of persistent ectopic pregnancy can be significantly reduced after a single prophylactic dose of systemic methotrexate administered postoperatively 11. in conclusion, this is the unique case, given the non - specific nature of symptoms, found to have a fimbrial ectopic pregnancy as well as a coexistence of endometriosis and mature cystic teratoma of the same ovary. because endometriosis is a chronic disease with high recurrence rates, the management of this rare case documented the simultaneous presence of endometriosis and mature cystic teratoma in the same ovary is faced by unresolved questions such as whether intervention is surgery alone or in combination with medical therapy. coexistence of varied pathology in a single organ makes it even more complex to justify one approach over another, especially for further follow - up. close follow - up of this patient is imperative, given the risk of persistent ectopic pregnancy and the risk of future recurrence of endometriosis. | key clinical messagea coexistence of endometriosis and mature cystic teratoma in the same ovary is a rare occurrence although such tumors of ovaries are said to be common in the reproductive age group. we report a case of fimbrial ectopic pregnancy combined with simultaneous ipsilateral ovarian presentation of endometriosis and mature teratoma. |
denmark s national health service provides free and equal access to health care for the entire population. health services related events are recorded in national databases, including the danish hospital register and the danish prescription database. information from both registries can be linked to each other by the use of the unique 10-digit central population registry number applied to all residents in denmark. parkinson s disease cases were ascertained from the computerized danish hospital register, with all hospitalizations with parkinson s disease diagnoses registered since 1977 and all clinic visits, including outpatient clinics, since 1995. individual information on the date of death, disappearance, or emigration was obtained from the central population registry. we identified 82,140 subjects (13,695 patients with parkinson s disease and 68,445 individuals without parkinson s disease) in the danish hospital register in the period 19862006 who 1) had a valid central population registry number, 2) were aged > 35 years at the time of diagnosis, and 3) had not emigrated from denmark. however, to allow for long enough lag times between diabetes and parkinson s disease, only individuals who were registered for the first time with a primary diagnosis of parkinson s disease (icd-10 code g20) between january 2001 and december 2006 (or had no previous hospitalization) were considered for inclusion as case subjects in our analyses. earliest date of a parkinson s disease diagnosis, we dated the primary parkinson s disease diagnoses back to either the first hospital or outpatient record that ever mentioned parkinson s disease or the first prescription of parkinson s disease medications (anatomical therapeutic chemical [atc ] code n04b) since inception of the danish prescription database (1995), whichever came first. patients with parkinson s disease whose backdated diagnosis date fell into the period prior to 2001 were excluded, leaving 2,188 patients with parkinson s disease. of these, we further excluded patients with parkinson s disease who had never received a parkinson s disease drug prescription (257 case subjects). to more efficiently control for confounding by the two most important risk factors for parkinson s disease, we then individually matched five randomly selected control subjects (i.e., individuals without parkinson s disease at the index date) from the central population registry by sex and year of birth to each case subject, using incidence - density sampling (17). the date of parkinson s disease diagnosis served as the index date for control selection. this left a total of 1,931 case subjects with parkinson s disease and 9,651 control subjects for our primary analyses. in secondary analyses, to further examine the potential for disease misclassification, we excluded parkinson s disease case subjects diagnosed with any type of dementia (both alzheimer s type and unspecified for icd-8 codes 2900929011, 2901829019, and 29309 and for icd-10 codes f00.x, f03, and g30) or cerebrovascular disease (icd-8 codes 430438 and icd-10 codes i60i69 and g45g46) in the 2 years preceding their parkinson s disease diagnosis (135 case subjects) and case subjects who used neuroleptics (atc codes n05aa, n05ab, n05ac, n05ad, n05af, and n05ag) in the 6 months preceding parkinson s disease diagnosis (194 case subjects). finally, we obtained a full history of hospitalization backdating to 1977 for all case and control subjects and calculated the charlson comorbidity score, a weighted index of 19 medical conditions (18), with a lag - time of 5 years prior to index date as an indicator of baseline morbidity. 2002 - 41 - 2112) and the university of california los angeles human subject review board. information on whether parkinson s disease case and control subjects had a diabetes diagnosis prior to the index date was extracted by use of the central population registry number from the national danish hospital register using the icd codes for diabetes (249 and 250.x for icd-8 and e10e14 for icd-10). because icd misclassification of insulin - dependent diabetes (also known as type 1 diabetes, icd-8 code 249 and icd-10 code e10) and non insulin - dependent diabetes (also known as type 2 diabetes, icd-8 code 250 and icd-10 codes e11e14) is prevalent (19,20), and because of inconsistencies in diabetes codes between icd-8 and icd-10, we chose not to present stratified analyses by subtype of diabetes. since 1 january 1995, the danish prescription database has received data on all dispensed prescriptions from pharmacies in denmark, including the individual s central population registry number, drug type by atc code, and prescription dispensing date. use of antidiabetes drugs by study subjects prior to the index date was extracted from this database, including atc groups a10a (insulins and analogs), a10b (oral blood glucose lowering drugs, including sulfonylureas [e.g., gliclazide ] and biguanides [e.g., metformin ]), and a10x (other drugs used in diabetes). we defined antidiabetes drug use as any filling of one or more prescriptions during the relevant period prior to the index date ; nonusers never filled a single prescription. we also categorized study participants into insulin users versus oral diabetes medication users according to atc code. we used unconditional logistic regression to calculate odds ratios (ors) and 95% cis for diabetes, while adjusting for age (continuous), sex, and chronic obstructive pulmonary disease (copd ; as a proxy for heavy smoking) diagnosis (icd-8 codes 490.00, 491.00, 491.01, and 491.03 and icd-10 code j44) identified in the danish hospital register. comorbidities registered before the index date (using the charlson index) were based on icd codes for 19 chronic disease categories recorded in the hospital records, including diabetes (18). parameter estimates changed by 60 years) and sex. in sensitivity analyses aimed at reducing parkinson s disease misclassification, we excluded case subjects (and their matched control subjects) and all control subjects diagnosed with dementia or cerebrovascular disease 2 years prior to parkinson s disease diagnosis of the index case. information on whether parkinson s disease case and control subjects had a diabetes diagnosis prior to the index date was extracted by use of the central population registry number from the national danish hospital register using the icd codes for diabetes (249 and 250.x for icd-8 and e10e14 for icd-10). because icd misclassification of insulin - dependent diabetes (also known as type 1 diabetes, icd-8 code 249 and icd-10 code e10) and non insulin - dependent diabetes (also known as type 2 diabetes, icd-8 code 250 and icd-10 codes e11e14) is prevalent (19,20), and because of inconsistencies in diabetes codes between icd-8 and icd-10, we chose not to present stratified analyses by subtype of diabetes. since 1 january 1995, the danish prescription database has received data on all dispensed prescriptions from pharmacies in denmark, including the individual s central population registry number, drug type by atc code, and prescription dispensing date. use of antidiabetes drugs by study subjects prior to the index date was extracted from this database, including atc groups a10a (insulins and analogs), a10b (oral blood glucose lowering drugs, including sulfonylureas [e.g., gliclazide ] and biguanides [e.g., metformin ]), and a10x (other drugs used in diabetes). we defined antidiabetes drug use as any filling of one or more prescriptions during the relevant period prior to the index date ; nonusers never filled a single prescription. we also categorized study participants into insulin users versus oral diabetes medication users according to atc code. we used unconditional logistic regression to calculate odds ratios (ors) and 95% cis for diabetes, while adjusting for age (continuous), sex, and chronic obstructive pulmonary disease (copd ; as a proxy for heavy smoking) diagnosis (icd-8 codes 490.00, 491.00, 491.01, and 491.03 and icd-10 code j44) identified in the danish hospital register. comorbidities registered before the index date (using the charlson index) were based on icd codes for 19 chronic disease categories recorded in the hospital records, including diabetes (18). parameter estimates changed by 60 years) and sex. in sensitivity analyses aimed at reducing parkinson s disease misclassification, we excluded case subjects (and their matched control subjects) and all control subjects diagnosed with dementia or cerebrovascular disease 2 years prior to parkinson s disease diagnosis of the index case. case subjects and their control subjects combined were on average 72.2 years of age (sd 10.2) at the index date. five years prior to the index date, case subjects had less copd than control subjects, although this difference was not statistically significant (table 1). at the index date, 6.4% of our study population had received a prescription for any type of oral antidiabetes medication or insulin ; antidiabetes drug prescriptions included oral blood glucose lowering drugs, including sulfonylureas (e.g., gliclazide [43.4% ]) and biguanides (e.g., metformin [25.3% ]) as well as insulin (26.6%), and 53% of subjects had received more than one type of antidiabetes prescription. the median length of time for receiving prescriptions for oral antidiabetes medication since 1995 and prior to the index date was 5.5 years for case subjects and 5.2 years for control subjects and for insulin was 6.0 years among the case subjects versus 4.9 years in the control subjects. characteristics of the danish study population, 20012006 data are n (%) or means sd. five - year lag : variables are ascertained 5 years prior to the index date or date of parkinson s disease diagnosis ; copd is a proxy for heavy smoking ; charlson comorbidity score is a weighted index of 19 medical conditions. in our main logistic regression analyses using a 2-year lag and relying on diabetes diagnoses based on icd codes, we estimated an overall 36% increase in the risk of developing parkinson s disease (95% ci 1.081.71) among those with diabetes (data not shown). in stratified analyses (with a 2-year lag), associations were slightly stronger in women (or 1.50 [95% ci 1.022.22 ]) than in men (1.29 [0.971.72 ]) and mainly seen in all patients with early - onset parkinson s disease (i.e., aged 2 years prior to parkinson s disease onset (or 1.35 [95% ci 1.101.65 ]) (table 2). in analyses based on 0-year and 5-year lags instead, our risk estimates were comparable in size (0-year lag : 1.21 [1.001.47 ] ; 5-year lag : 1.35 [1.071.72 ]). overall, these associations were somewhat stronger for users of oral diabetes medication than for insulin users (or 1.37 vs. 1.22) (see table 2). association between diabetes (2-year lag, i.e., diabetes was present at least 2 years prior to the index date) and parkinson s disease data are n or or (95% ci). model 1 : adjusted for age and sex ; model 2 : adjusted for age, sex, and copd (lagged 5 years). diagnosis of diabetes based on any prescription of antidiabetes drugs (atc codes). in stratified analyses (with a 2-year lag), risk estimates differed for men and women and also for those younger (aged < 60 years) or older (aged 60 years) at diagnosis / index date, whereas the risk of developing parkinson s disease associated with the use of any type of antidiabetes drug was very similar for men and women (men : or 1.33 [95% ci 1.031.72 ] ; women : 1.38 [0.991.92 ]) ; among those using oral diabetes medication, only women were at higher risk of developing parkinson s disease (men : 0.74 [0.371.50 ] ; women : 2.92 [1.346.36 ]). by contrast, men with diabetes who use insulin experienced a 48% higher risk of developing parkinson s disease (1.48 [1.131.95 ]), whereas the risk was slightly lower in women (1.20 [0.831.74 ]). similar to our icd code based results, when stratifying by age at onset of parkinson s disease (aged < 60 years vs. 60 years at onset), the risk of parkinson s disease was much higher among patients with diabetes using antidiabetes drugs in early onset (3.07 [1.655.70 ]) than in late - onset parkinson s disease (1.24 [0.991.53 ]). on closer examination, this difference tended to be largely attributed to insulin use, as opposed to the use of oral antidiabetes medications : for early - onset parkinson s disease (albeit based on two cases only), the risk associated with insulin use was 3.74 (1.897.38) and 1.32 (0.286.26) for use of oral antidiabetes medication, whereas these risks were 1.24 (0.981.57) and 1.21 (0.712.06), respectively, for late - onset parkinson s disease. generally, these associations tended to be attenuated in 0-lag analyses and slightly stronger in the 5-year lag analyses (data not shown). when we further stratified by sex, albeit based on small case numbers, we found these associations particularly for oral antidiabetes medications (we did not have enough power to examine this for insulin use), again stronger for early - onset parkinson s disease, regardless of sex. in sensitivity analyses, we excluded parkinson s disease patients and control subjects diagnosed with dementia or cerebrovascular diseases 2 years prior to the index date, but the risk estimates changed only minimally (data not shown). similarly, excluding case subjects with neuroleptic use within 6 months prior to parkinson s disease diagnoses did not alter our findings substantially (or for any use of antidiabetic drugs 1.26 [95% ci 1.011.56 ]). we identified all case subjects with a primary diagnosis of parkinson s disease in denmark from hospital and outpatient clinic records between 2001 and 2006. in our analyses, both icd code based hospital and outpatient clinic reports of diagnoses of diabetes (which does not allow us to distinguish between type 1 and type 2 diabetes), as well as the use of antidiabetes drugs (which, to some degree, allows us to distinguish between type 1 and type 2 diabetes, as individuals using oral diabetes medications only are likely to have type 2 diabetes), these associations became stronger with longer lag times and showed differences in subgroup analyses (i.e., the associations were markedly stronger for early - onset parkinson s disease, particularly for insulin use, vs. the risk for early - onset diabetes and was more modest when oral antidiabetes drugs were used to treat diabetes). among female subjects, oral antidiabetes drugs were more strongly associated with overall risk of parkinson s disease than among men, and oral antidiabetes drugs also appeared to drive the association with early - onset diabetes in men. observational studies that previously examined associations between diabetes and parkinson s disease have produced mixed results. although most of the published epidemiologic studies reported a positive association between diabetes and parkinson s disease (2,9,10,13) or parkinsonian signs (5) and drug - induced parkinsonism (4), some studies reported no association (6,11) and others even inverse associations (7,12). a cross - sectional study of 791 patients with parkinsonism that had linked u.s. national survey data of 24,831 elderly to 1.9 million medicare claims found that those with parkinsonism had a 50% (men) to 70% (women) higher risk of concurrent diabetes (13). in a selected group of 1,030 u.s. elderly subjects without a diagnosis of parkinson s disease, diabetes was found to be associated with a more severe score of global parkinsonian signs, which was used to determine the degree of motor dysfunction (5). similar to our results, these researchers also found the association of diabetes with parkinsonian signs to be similar among men and women but stronger in younger compared with older patients (5). by contrast, in a case - control study of 490 parkinson s disease patients derived from a neurologist s private - practice database, the prevalence of diabetes was found to be similar in those with and without parkinson s disease (12.9 vs. 12.1%) (11). three small case - control studies of 352 (12), 318 (7), and 178 (14) newly diagnosed patients with parkinson s disease reported inverse associations with diabetes prior to parkinson s disease (or 0.52 for men with diabetes vs. or 0.80 for women with diabetes in the first, or 0.40 in the second, and or 0.30 in the third study). moreover, a study based on the u.k. general practice research database reported the diabetes prevalence to be similar in patients with and without parkinson s disease and the risk of developing diabetes to be lower in parkinson s disease patients (6). in the most recent retrospective study, a hospital - based case - control study conducted in japan (16) and comprising 250 new - onset parkinson s disease (within 6 years of diagnosis), a decreased risk of parkinson s disease was observed among individuals with a history of diabetes (or 0.38 [95% ci 0.170.79 ]). this risk did not vary by sex ; however, neither was age at onset of parkinson s disease nor type of medication used taken into account in this retrospective analysis. the few prospective studies that evaluated associations between diabetes and parkinson s disease published to date tended to report positive associations between the two conditions. in a prospective study of 51,552 finnish men and women, a diabetes diagnosis at baseline was associated with an 85% increased risk of developing parkinson s disease (9). based on data from two large prospective cohorts, the nurses health study cohort and the health professionals follow - up study (15), the relative risk for developing parkinson s disease was 1.12 (95% ci 0.691.81) among those with a baseline history of diabetes. (8), who used data from a large male prospective cohort, the physicians health study. the authors describe an overall increased risk of parkinson s disease associated with diabetes (1.34 [1.011.77 ]), a relative risk strikingly similar in magnitude to our own findings. however, in contrast to our own results, they reported that most of the excess diabetes risk occurred in the year prior to and the year of parkinson s disease diagnosis and speculated that this positive association may therefore either be driven by surveillance bias or by a common underlying biologic mechanism causing both diseases and yet to be determined. in our study, we excluded both first diabetes diagnoses based on icd codes as well as antidiabetes drug use by up to 5 years prior to index date and found that associations tended to become stronger with such lagging, especially when using antidiabetes medications to identify diabetic case subjects. in a previous publication based on the same danish dataset, we explored associations between autoimmune diseases, including insulin - dependent diabetes defined by icd-8 code 249 and parkinson s disease risk during a longer period of observation (19862006) (21). on the basis of icd codes alone, we observed a higher risk of parkinson s disease (or 1.6 [95% ci 1.022.5 ]) only in women, whereas no association was apparent among men using insulin (0.8 [0.51.2 ]) when lagging the diabetes diagnoses by 5 years. differences in the present results are likely attributed to the different types of diabetes included in the studies (only insulin - dependent diabetes in the previous study and both insulin and non insulin dependent diabetes in this study) and possibly also our use of a more refined parkinson s disease definition based on a combination of parkinson s disease icd codes and parkinson s disease drug prescriptions in the current study. insulin has been implicated in alzheimer s disease risk. whether this is primarily a result of vessel damage caused by long - term elevated blood glucose levels as the primary mechanism behind these associations is currently unknown. however, given that parkinson s disease is not primarily a vascular disease, we speculate that an association between diabetes and parkinson s disease, as found in our study, could suggest a different pathway, especially because the associations seemed to be stronger in younger - onset parkinson s disease (i.e., patients less likely to be affected by cerebrovascular disease). one such pathway might be related to vitamin d levels, which have been implicated in both diseases (i.e., it has been suggested that vitamin d lowers both the risk of parkinson s disease and type 2 diabetes) (2224). we found substantial differences in estimated effect size between diabetes and parkinson s disease by age at onset of parkinson s disease, although this difference is based on small numbers of patients with early onset. only one previous study, examining the association between diabetes and parkinsonian signs, was able to address this, and they too report the association between diabetes with parkinsonian signs to be stronger in younger compared with older patients (5). although there also were differences for insulin users versus oral diabetes medication users in relation to parkinson s disease by sex and age at onset, statistical power issues limited our ability to explore these substrata in greater detail. overall, the stronger associations with early - onset parkinson s disease are suggestive of a common genetic origin and might serve as an explanation as to why previous studies were contradictory, as they were not able to stratify according to early- or late - onset parkinson s disease. recently, an intriguing hypothesis emerged that may link parkinson s disease and diabetes via the mitochondrial dysfunction pathway. neurons in the substantia nigra (parkinson s disease) as well as pancreatic islet -cells (affected in diabetes) have been described as cells with low respiratory capacity / low mitochondrial capacity and therefore have a greater sensitivity to defects or impairments in mitochondrial respiratory chain enzymes than other cells with higher respiratory capacity. thus, both cell types (substantia nigra and islet -cells) are more vulnerable to defects or toxins that further diminish the capacity to generate atp when the mitochondrial genome accumulates genetic lesions during aging. in a study comparing 64 japanese centenarians to 61 patients with parkinson s disease (25), tanaka (25) found a by - far - greater frequency of deleterious mitochondrial variants and a much greater variety of amino acid replacements among parkinson s disease patients ; in contrast, such variations were absent in centenarians. given the above - mentioned bioenergetic similarity of substantia nigra and pancreatic islet -cells in terms of their ability to respond to mitochondrial impairment, this could provide a pathogenetic link between parkinson s disease and diabetes. strengths of our study are that control subjects were selected at random from a population registry and did not have to volunteer information for our study, thus avoiding bias attributed to selective nonparticipation. we required that all parkinson s disease case subjects had been admitted at least once with a primary diagnosis of parkinson s disease, and, whenever possible, we dated diagnoses back to the likely earliest diagnosis (e.g., a first prescription of parkinson s disease medications). limitations include some disease misclassification because primary parkinson s disease diagnoses were identified from hospital records that may have included some cases of nonidiopathic parkinsonism. sensitivity analyses in which we excluded parkinson s disease case subjects with prior diagnoses of dementia and cerebrovascular diseases in the 2 years before parkinson s disease diagnosis, and parkinson s disease case subjects with neuroleptic use in the 6 months preceding diagnosis suggested the bias to be minimal. we might have selected less healthy parkinson s disease case subjects more likely to be hospitalized than danish parkinson s disease patients seen exclusively by private practitioners without ever attending a specialty clinic before 2007. the slightly higher charlson index and greater number of cardiovascular disease drug prescriptions among our study s parkinson s disease patients compared with control subjects 2 years prior to and at the index date (data not shown) supports, albeit only modestly, the possibility for such a selection bias. however, differences in general health status were not evident 5 years prior to parkinson s disease diagnosis / index date. the universal coverage of most health care expenses in denmark, including partial reimbursement of costs for prescribed drugs, makes it less likely that antidiabetes drug prescriptions or parkinson s disease diagnoses were influenced by factors determining access to care. in addition, we may have missed diabetes case subjects who never took any antidiabetes drugs ; however, results from icd - based diabetes diagnoses were very similar to those based on antidiabetes drug use. we were unable to fully control for smoking, known for its strong negative association with parkinson s disease, although our adjustment for copd as a proxy for heavy smoking may have, at least partly, controlled for smoking. in summary, evidence is accruing for an association between diabetes and parkinson s disease. whether this association is causal or a result of a common pathophysiologic pathway still needs to be determined, although a common biologic pathway appears to be the most plausible explanation at this point. future studies of the association between diabetes and parkinson s disease should take age at onset of parkinson s disease into account. | objectiveinsulin contributes to normal brain function. previous studies have suggested associations between midlife diabetes and neurodegenerative diseases, including parkinson s disease. using danish population registers, we investigated whether a history of diabetes or the use of antidiabetes drugs was associated with parkinson s disease.research design and methodsfrom the nationwide danish hospital register hospital records, we identified 1,931 patients with a first - time diagnosis of parkinson s disease between 2001 and 2006. we randomly selected 9,651 population control subjects from the central population registry and density matched them by birth year and sex. pharmacy records comprising all antidiabetes and anti - parkinson drug prescriptions in denmark were available. odds ratios (ors) were estimated by logistic regression models.resultshaving diabetes, as defined by one or more hospitalizations and/or outpatient visits for the condition, was associated with a 36% increased risk of developing parkinson s disease (or 1.36 [95% ci 1.081.71 ]). similarly, diabetes defined by the use of any antidiabetes medications was associated with a 35% increased parkinson s disease risk (1.35 [1.101.65 ]). when diabetes was defined as the use of oral antidiabetes medications, effect estimates were stronger in women (2.92 [1.346.36 ]), whereas when diabetes was defined as any antidiabetes drug prescription, patients with early - onset parkinson s disease were at highest risk (i.e., parkinson s disease diagnosed before the age of 60 years ; 3.07 [1.655.70]).conclusionswe found that a diagnosis of, or treatment received for, diabetes was significantly associated with an increased risk of developing parkinson s disease, especially younger - onset parkinson s disease. our results suggest a common pathophysiologic pathway between the two diseases. future studies should take age at parkinson s disease onset into account. |
due to environmental changes, the global incidence of tick - borne disease is increasing worldwide, thus tick - borne diseases have been listed alongside diseases with high emergence risk. several tick - borne pathogens have already emerged in certain geographical regions, such as tick - borne encephalitis virus and crimean congo haemorrhagic fever virus, and novel tick - borne pathogens are continually being discovered. a proportion of these viruses are zoonotic (severe fever with thrombocytopenia syndrome virus in china, the heartland virus and the bourbon virus in the usa) but the pathogenicity of many others is poorly documented. consequently, it is extremely important to determine the pathogenicity of these viruses, and their potential involvement in undiagnosed animal or human febrile illness or encephalitis. ticks are widespread throughout europe and are the primary arthropod vector of both human and domestic animal disease agents. in terms of public health, the most important european tick is ixodes ricinus, the vector of the lyme borreliosis bacteria,. ixodes ricinus can transmit many varieties of pathogens, including bacteria, parasites and viruses, due to specific biological adaptations and its capacity to feed on numerous different animal species. the most prevalent tick - borne disease transmitted by i. ricinus is lyme borreliosis, with over 85 000 new european cases annually,. however, patients bitten by ticks can also be infected by many other zoonotic pathogens, including parasites, viruses and other bacteria,. some of these pathogens were initially identified in ticks decades before their association with human disease (such as borrelia miyamotoi), whereas others have only been discovered very recently (such as the bourbon virus). the global incidence of tick - borne disease is increasing worldwide as the result of environmental changes, so tick - borne diseases are now highlighted as having significant emergence risk,,,. several tick - borne pathogens have already emerged in specific geographical regions, such as the tick - borne encephalitis virus (tbev), louping ill virus, powassan virus, deer tick virus, severe fever with thrombocytopenia syndrome virus and crimean congo haemorrhagic fever virus,,,,, whereas novel tick - borne pathogens are continually being discovered,,,. these factors highlight the importance of studying viral epidemiology in tick populations. although ticks have the potential to transmit many different viruses, most studies surveying tick - borne pathogens in europe have focused on bacterial and/or parasitic pathogens. numerous reports detailing parasitic or bacterial prevalence in either european ticks or animal reservoirs are published every year,,,,. for viruses for instance, even though several tick - borne encephalitis cases have been reported in france,, recent data on tbev prevalence in i. ricinus or animal reservoirs in france do not exist. moreover, no data are available regarding the prevalence of other tick - borne viruses in europe. this lack of knowledge and relevant data within ticks is surprising, but may be explained by the fact that it is far easier to detect bacterial and parasitic dna, because they possess the conserved rrna genes that are most often targeted by broad - range molecular testing. subsequently, many laboratories, including ours, have focused their research on bacteria and parasites rather than viruses. in this study, we aimed to describe the global picture of viruses carried by french i. ricinus, using rna deep sequencing to identify and better characterize both dna and rna viruses that replicate in ticks. the vast majority of hits mapped to families known to include arboviruses, and the greatest number of contigs probably designated a novel nairovirus and a new phlebovirus. the only known virus identified in the ticks was the eyach virus, first isolated in europe in the 1980s, and which has since been forgotten. here, we demonstrated its capacity to multiply and persist in the blood of of1 mice, and its ability to colonize murine brains. questing i. ricinus female ticks (268 in ardennes), male ticks (228 in ardennes) and nymphs (285 and 1455 in ardennes and alsace, respectively) were collected by flagging from northeastern france (ardennes in 2012 49.574177, 4.802835 ; alsace in 2010 47.918066, 7.146111). all collected ticks were washed as previously described, nymphs were pooled into groups of 15 individuals (116 pools in total) and adults were individually treated. before rna extraction, tick samples were crushed in 300 l dulbecco 's modified eagle 's medium supplemented with 10% fetal calf serum. a pathogen - free colony was obtained as follows ; females from the field were engorged on rabbits and allowed to lay eggs. dna and rna samples were extracted from female ticks and pcrs were performed to test for the presence of borrelia spp., bartonella spp., anaplasma spp., rickettsia spp., francisella spp. and coxiella spp. only larvae from pathogen - free female ticks were conserved and maintained in our colony before use in high throughput sequencing (hts) experiments. newborn (72 h old) type i interferon receptor knock - out mice (ifnar, genetic background : a129svevbrd)) kindly provided by dr damien vitour (virology unit, animal health laboratory, anses) were used for viral isolation from tick extracts. females (45 weeks old) and newborn of1 mice (72 h old) (charles river company, wilmington, ma, usa) were used for studying the course of the eyach virus infection. animal experiments were carried out in strict accordance with appropriate animal care practices as recommended by european guidelines. protocols were approved by the anses - enva - upec ethics committee for animal experimentation (agreement number : 13 - 021). crushed ticks (individual adults or pooled nymphs) one half was directly frozen at 80c for subsequent viral isolation, the other half was used for total rna extraction using the nucleospin rna ii kit (macherey - nagel, duren, germany) following the manufacturer 's instructions. rna samples were pooled relating to their geographical area (one ardennes pool and one alsace pool). the pooled rna samples were retro - transcribed to cdna, and randomly amplified using the multiple displacement amplification (mda) protocol with phi29 polymerase and random hexamers as described previously. library preparations and sequencing with an illumina hiseq2000 sequencer were outsourced to dnavision (charleroi, belgium). wild and pathogen - free samples were sequenced to a depth of 200 10 (alsace sample), 131 10 (ardennes sample) and 62 10 (pathogen - free sample) paired - end reads of 101 bp. raw sequence reads were trimmed according to their quality score. at the time of analysis, there was no publicly available reference genome for i. ricinus, so tick sequences were removed from the analysis by subtracting sequences identical to those derived from a pathogen - free reference sample using the soap2 aligner tool. finally, de novo assembly was performed on all remaining reads (5.2 10 and 7.8 10 for the ardennes and alsace tick samples, respectively) using clc assemblycell software (version 4.0), producing 16 094 and 174 841 contigs in the ardennes and alsace tick samples, respectively. taxonomic assignation of these contigs was achieved by successive sequence alignment using nucleotide and protein databases and the blast algorithm. contigs were assigned the closest known taxonomy according to their identity percentage, and distant alignments were not considered. for all viruses, primers and probes eyach virus rna was detected in ticks by quantitative rt - pcr targeted to the vp2 gene (primer f : 5-tggctgacaacatgacggata-3 ; primer r : 5-ggcctcacgatactttcgatt-3) ; probe (5-fam - acgggctcggtacttcggttgagat - bhq1 - 3). the quantitative rt - pcrs were performed in a final volume of 20 l using lightcycler 480 rna master hydrolysis probes (roche applied science, penzberg, germany), with primers at 0.5 m, the probe at 0.25 m and 2 l of rna (quantity range from 200 to 400 ng). thermal cycling conditions were 63c for 3 min, 95c for 30 sec, 45 cycles at 95c for 10 sec, and 60c for 30 sec and one final cooling cycle at 40c for 30 sec. each rna sample was run in duplicate. to detect the novel nairovirus and phlebovirus rna, the cdna synthesis step was performed with random hexamers (superscript iii rt ; invitrogen inc., amplification of l, m and s segments from each new nairovirus and phlebovirus was performed using 22 specific primer pairs (table 1) designed from hts - contigs. all pcr amplifications were performed by using the taq core kit (mpbio, illkirch, france) following the manufacturer 's instructions. newborn ifnar mice (48 to 72 h old) were directly inoculated with 20 l of tick extracts positive for either the novel nairovirus or eyach virus (pool of ticks numeros e48 and e134). mice were observed daily, and if paralysis occurred, mice were euthanized, and their brains were harvested and homogenized in medium. rna was extracted using the nucleospin rna ii macherey - nagel kit following the manufacturer 's instructions, viral rna was detected by quantitative rt - pcr as described above. purified rna from mouse brains infected with eyach - positive tick extracts was amplified as previously described for tick rna and sequenced on a life technologies proton sequencer using a single chip (around 80 10 reads). genome sequences were derived from de novo assembled contigs. for phylogenetic analysis, hts - contig sequences of eyach virus strains from the rna - dependent rna polymerase gene (segment 1) from french ticks (deposited in genbank, accession numbers ku133666ku133676, ku133678, ku133679) were compared to seven available genbank sequences of eyach virus using maximum likelihood trees (genbank reference sequences af343052, eu789374eu789377, af282467 and af343053). the colorado tick fever virus was selected as an outgroup (genbank reference sequence nc_004181). eyach virus inoculum obtained from the brain homogenates of infected newborn ifnar mice (2.4 10 copy/l) was intraperitoneally injected into of1 mice : five females (100 l) and nine newborn mice (40 l). for controls, adult and newborn of1 mice were respectively intraperitoneally inoculated with 100 l and 40 l of 1 pbs. mice (infected and negative controls) were observed and weighed daily until day 21. recorded clinical signs included significant weight loss, weakness, ruffled fur, hunched posture, ataxia, tremors and occasionally hind leg paralysis. blood samples (infected and negative controls) were collected from newborn (40 l) and adult (100 l) mice at days 7, 14 and 21. brains and spleens were individually crushed in 500 l dulbecco 's modified eagle 's medium before rna extraction. rna was extracted from total blood, brain or spleen homogenates using the nucleospin rna ii macherey - nagel kit following the manufacturer 's instructions. for each rna sample (brain, spleen, blood), digital rt - pcr was performed to quantify eyach vp2 segments. digital rt - pcr amplifications were performed on a fluidigm biomark system using digital array microfluidic chips (fluidigm corporation, san francisco, ca, usa). reactions were performed in 8 l of reaction mixture containing 0.4 l of sample loading reagent (biomark), 1.6 l of roche rt mix (roche), 0.4 l of rt superscript iii (invitrogen), 0.16l of rox reference dye (biomark), 0.4 l of primer stock (mixture of primers and probe at a final concentration of 18 m for each primer and 4 m for probe), and 3.1 l rna (quantity range from 620 ng to 1240 ng), or water for negative controls. half of the 8 l reaction mix was loaded onto the chip with the integrated fluidic circuit controller, effectively partitioning 0.65 l (equivalent to 0.25 l rna ; quantity range to 50 ng to 100 ng) into each of the 770 chambers per panel. the one - step digital rt - pcr programme involved a step of 25c for 10 min, one step of reverse transcription at 50c for 50 min, followed by a 5-min denaturation step at 95c, and lastly 45 cycles of 10 sec at 95c and 30 sec at 60c. the digital pcr analysis software, part of the biomark system (fluidigm corporation) was used to count the number of positive chambers out of the total number of chambers per panel. poisson distribution was used to estimate the average number of template copies per chamber in a panel. numbers of viral rna copies in the blood of females at days 7, 14 and 21 were compared using the online kruskal numbers of viral rna copies in the blood of females compared with newborn mice at day 7, day 14 and day 21 were done using the online wilcoxon rank sum test. metatranscriptome analysis was performed on two pooled i. ricinus rna samples : subsequently termed the alsace sample and the ardennes sample, and detected pathogens including replicating dna and rna viruses, including 174 841 and 16 094 assembled contigs were generated for the alsace and ardennes samples respectively. of these contigs, 395 and 150 had best hits corresponding to eukaryote viruses belonging to viral genera comprising eukaryotic viruses of vertebrates and/or arthropods. 1(a, b) illustrates the viral family distribution of read counts used to assemble the 395 and 150 contigs. the vast majority of hits mapped to virus families known to replicate in arthropods. most belonged to bunyaviridae (nairovirus, phlebovirus, orthobunyavirus), reoviridae (coltivirus), rhabdoviridae (vesiculovirus, sigmavirus), picornaviridae - like (iflavirus, drosophila virus a) families (see table 2 for the alsace sample and table 3 for the ardennes sample). hits with high nucleotide identity (94%100%) were all assigned to the identical coltivirus virus, i.e. eyach virus. all other hits were distant from known viruses (50% mean nucleotide identity, range 25%72%), most belonged to families known to replicate in arthropods. the most frequently occurring contigs corresponded to the nairovirus and phlebovirus genera in both the ardennes and alsace samples, (68/395 and 39/395 contigs, respectively, for the alsace sample, and 25/150 and 16/150 contigs, respectively, for the ardennes sample). these contigs corresponded to all three viral genome segments (l, m and s). none of the contigs corresponded to any of the three viral genome segments from other viral genera belonging to the bunyaviridae family. we then focused on the little - known or new viruses for whom hts analyses gave the most complete data. subsequently, we evaluated the prevalence of the eyach virus, and the likely novel nairovirus and phlebovirus members in ticks, by identifying infected ticks, and then used crushed tick extracts in further isolation and characterization studies. the prevalence of the eyach virus, novel nairovirus and novel phlebovirus rna viruses was calculated in adult ticks (female and male) from the ardennes, and was estimated in pooled nymphs from both the alsace and ardennes regions. the prevalence of eyach virus rna was 1.87% in female adult ticks (5/268) and 0.88% in adult males (2/228). in the ardennes samples, 1/19 nymph pools (each comprising 15 nymphs) was positive, indicating that in nymphs, prevalence ranged between 0.35% (if only one nymph was positive per pool) and 5.26% (if all 15 nymphs were positive in each pool). in alsace ticks, 1/97 nymph pools was positive, with an estimated nymph prevalence ranging between 0.07% and 1.03%. concerning the new nairovirus, only the l segment was detected in adult ticks from ardennes, with a prevalence of 23.88% in females (64/268) and 16.67% in males (38/228). in nymphs from alsace, all three segments were detected with prevalences ranging between 4.81% and 72.16% (70/97) for the l contig, between 0.14% and 2.06% (2/97) for the m contig, and between 0.48% and 7.22% (7/97) for the s contig. for the new phlebovirus member(s), only the l segment was detected in adult ticks from ardennes with a prevalence of 5.60% in females (15/268), and 3.95% in males (9/228). in the nymph pools from ardennes, only the l and m fragments were detected : 13/19 nymph pools were positive for the l segment, indicating that in nymphs, the l - segment prevalence ranged between 4.56% and 68.42% ; the m contig was detected in 1/19 nymph pools, with a prevalence between 0.35% and 5.26%. no pools were simultaneously positive for both the l and m fragments. in alsace nymphs, only the l segment was detected with a prevalence ranging between 2.82% and 42.27% (41/97). we attempted eyach virus and new nairovirus isolation from tick extracts positive for all three segments. as no tick extracts carried more than one new phlebovirus segment, we did not attempt isolation of this virus. the absence of all three phlebovirus segments in tick extracts may reflect low viral loads, or differences in pcr efficacies. to isolate the viruses, ifnar mouse brains were inoculated with tick extracts positive for all three segments of either the new nairovirus or the eyach virus. eyach virus was detected by quantitative rt - pcr in rna extracted from mouse brains infected with eyach - positive tick extracts, whereas none of the new nairovirus segments were detected by rt - pcr in the brains of mice infected with new nairovirus - positive tick extracts. sequencing one eyach virus - positive rna brain sample generated 17.9 10 reads with 109 contigs covering the 12 segments of the eyach viral genome (table 4). each eyach virus consensus segment was submitted to genbank (accession numbers : ku163321ku163332). contig identities comprised between 86% and 100% compared with the available eyach virus genome (af282467.1af282478.1af282467.1af282468.1af282469.1af282470.1af282471.1af282472.1af282473.1af282474.1af282475.1af282476.1af282477.1af282478.1). hts resulted in 93.8% coverage of the entire eyach genome, with nucleotide identity ranging between 83.3% and 99.2%, depending on the analysed segment (see supplementary material, fig. phylogenetic analysis of eyach virus segment 1 contigs (accession numbers ku133666ku133676, ku133678, ku133679) revealed that eyach genotypes identified in the alsace and ardennes regions were more closely related to the german eyach virus isolated from i. ricinus, than to other french eyach viruses isolated from i. ricinus and ixodes ventalloi collected in the west of france (fig. 2). we then investigated whether the virus could replicate in immunocompetent mice (adults and juveniles) following intraperitoneal inoculation. infected adults and newborn mice presented no obvious clinical signs of disease (such as weight loss, weakness, ruffled fur, hunched posture, ataxia, tremor) compared with controls. to assess eyach viral load in the blood, spleen and brain of each mouse, eyach virus rna was evaluated at days 7, 14 and 21 by digital rt - pcr (fig. viral rna persisted in the blood of the four females until day 21, with no statistical difference in copy numbers between days 7, 14 and 21 (p 0.1637), but was not detected in either the spleen or brain of the five adult females at day 21. viral rna was present in the blood of all newborn mice at each time - point, with the highest observed copy number / ml at day 14 (p 0.0344). viral rna was present in the spleens of 6/9 newborn mice and in the brains of 3/9 newborn mice at day 21. eyach viral copies were higher in newborn blood samples than in adult female blood samples (day 7, p 0.042 ; day 14, p 0.001 ; day 21, p 0.004). in this study we analysed the virome of i. ricinus, the most relevant tick species to animal and human health in europe. our ultimate aim was to uncover new or unsuspected tick - borne animal or human viruses in i. ricinus. interestingly, most of the eukaryotic viral sequences detected in i. ricinus belonged to probable new viruses, as only one previously known virus was identified, the eyach virus. this had been identified in the 1980s as a potential human pathogen in ticks but has not been studied subsequently. here, we isolated an eyach viral strain with neurotropism in mice, confirming that this virus has the capacity to infect vertebrates and traverse the blood brain barrier. although we can not draw conclusions regarding viral pathogenicity from these data, our results lay the foundation for several studies regarding the pathogen itself as well as their possible hosts and reservoirs. following the analysis of the two sets of hts sequences, we obtained contigs belonging to bunyaviridae (nairovirus, phlebovirus, orthobunyavirus), reoviridae (coltivirus), rhabdoviridae (vesiculovirus, sigmavirus) and picornaviridae - like (iflavirus, drosophila virus a) with nucleotide identity to known viruses ranging from 20% to 100%. among these contigs, predominant sequences were for viral families, which include arboviruses, suggesting that they are unlikely to represent background noise. most sequences shared < 80% identity with known viruses, potentially indicating new viral species. in both hts data groups (obtained from alsace and ardennes samples), the greatest number of contigs with relatively low percentage identity to known viruses, belonged to viruses from the nairovirus and phlebovirus genera. the nairovirus contigs demonstrated the closest taxonomies to pathogenic tick - transmitted nairoviruses, such as nairobi sheep disease virus, hazara virus, crimean congo haemorrhagic fever virus, or dugbe virus. concerning the phlebovirus - related contigs, most were related to non - pathogenic tick - associated viruses, such as blacklegged tick virus or uukuniemi virus. ticks had relatively high infection rates for both genera in the two geographical areas studied : between 3.95% and 23.88% in adults, and between 0.14% and 72.16% in nymphs. these rates are higher than have typically been reported for other tick - borne viruses, as tbev prevalence in european ticks is usually between 0.1% and 1.22%, and powassan virus prevalence in american ticks is often lower than 2%. however, high nairovirus and phlebovirus tick infection rates have previously been reported (from 5.7% to 23.5%),,. possible explanations for the high prevalence rates may be either due to extensive bioavailability of susceptible viraemic hosts, or because these viruses can be transovarially transmitted from females to offspring. in the latter case, these viruses could then be considered as endogenous tick viruses, where the ticks themselves play the role of long - term reservoirs. endogenous tick viruses are not necessarily able to infect vertebrates, and for many, almost nothing is known about their biology or their potential pathogenic effects on humans or animals. the inability to detect sequences corresponding to these new nairovirus after inoculating the brains of immunocompromised mice with positive tick extracts suggests that these viruses are unable to multiply in this particular vertebrate host. in addition to contigs corresponding to probable viruses, we identified contigs sharing more than 90% identity with another known virus. these contigs were all assigned to the same virus, eyach virus. this virus, a member of the coltivirus genus within the reoviridae family, was first isolated in i. ricinus collected from germany in 1972. subsequently, it was isolated in i. ventalloi and i. ricinus from france in 1981. since this time and despite the lack of surveillance, this virus is evidently still present in france. the eyach virus was indirectly incriminated in cases of encephalitis and polyradiculoneuritis in the former czechoslovakia, as antibodies to the virus were identified in sera from patients with a neurological syndrome, but no formal confirmatory viral identification occurred. nevertheless, solid demonstration of causality is still lacking. an animal reservoir for the eyach virus, if it does exist, remains unidentified, even though anti - eyach virus antibodies have been identified in many animal species in france, including the european rabbit (oryctolagus cuniculus), rodents, sheep, deer and mountain goats,. we demonstrated that eyach virus prevalence (0.07%5.26%) was similar in ardennes and alsace ticks and was similar to rates of tbev, which is endemic in the studied regions,. so far, no viral rna has been isolated from animals or humans ; however, successful isolation of the virus following intracerebral inoculation of mice with infected tick extract, indicated that the virus could possibly multiply in vertebrate hosts. this result was reinforced by the demonstration that after intraperitoneal inoculation in immunocompetent mice, the virus was able to multiply and persist in the blood for up to 21 days after infection. finally, we identified the virus in the brains of suckling mice as evidence of its neurotropism. more advanced analysis of the eyach virus should be performed to determine the presence of lesions and/or to determine specific cellular tropism in the brain. the long - lasting viraemia of eyach virus observed in of1 mice might suggest that rodents could be the natural reservoir of this virus. however, a preliminary prevalence study performed on bank voles collected in the same area as the ticks (ardennes) did not reveal the presence of the virus (cosson., unpublished data). in summary, there is still no clear evidence that the eyach virus infects humans or animals, so this will require additional investigation. currently, new tick - borne viruses are often isolated from humans with febrile illness or death following a tick bite, as occurred for severe fever with thrombocytopenia syndrome virus in china, the heartland virus, and the bourbon virus in the usa. but many other tick - borne viruses have been described without related human illness,, leading to new challenges and questions in the field of tick - borne disease research : are those new viruses potential pathogens for humans, and even more importantly, could these new viruses be linked to human disease. | ticks transmit more pathogens including bacteria, parasites and viruses than any other arthropod vector. although the epidemiological status of many tick - borne bacteria is very well characterized, tick - borne viruses are still relatively under - studied. recently, several novel tick - borne viruses have been isolated from human febrile illnesses following tick bites, indicating the existence of other potential new and unknown tick - borne viruses. we used high - throughput sequencing to analyse the virome of ixodes ricinus, the main vector of tick - borne pathogens in europe. the majority of collected viral sequences were assigned to two potentially novel nairovirus and phlebovirus viruses, with prevalence rates ranging from 3.95% to 23.88% in adults and estimated to be between 0.14% and 72.16% in nymphs. these viruses could not be isolated from the brains of inoculated immunocompromised mice, perhaps indicating that they are unable to infect vertebrates. within the i. ricinus virome, we also identified contigs with > 90% identity to the known eyach virus. initially isolated in the 1980s, this virus was indirectly associated with human disease, but had never been extensively studied. eyach virus prevalence varied between 0.07% and 5.26% in ticks from the french ardennes and alsace regions. eyach virus was successfully isolated following intracerebral inoculation of immunocompromised mice with eyach virus - positive tick extracts. this virus was also able to multiply and persist in the blood of immunocompetent mice inoculated by intraperitoneal injection, and caused brain infections in three of nine juveniles, without any obvious deleterious effects. |
a passive surveillance system of encephalitis in equine and avian species was set up to detect any occurrence of clinical signs of wnv infection. at the same time, a serologic investigation for wnv was conducted in guadeloupe archipelago. a cross - sectional study was performed on the most susceptible animal species (birds and horses). maarten island (635-185) on domestic ducks (family : anatidae, anas species), domestic geese (family : anatidae, anser sp.), and on laughing gulls (larus atricilla), a resident wild species. the french part of the island belongs to guadeloupe s archipelago and is located 270 km north of the main island. it is a major resting place for migratory birds, which spend some days or weeks on the ponds before migrating south in the fall (or north in the spring). therefore, st. martin was chosen to increase the probability of detecting the earliest serologic conversions on resident birds and to prove the circulation of wnv among resident birds and domestic avian species. a total of 50 ducks and geese from four backyards as well as ducks from the st. three gulls were caught and released after blood collection. on guadeloupe island (6130-1615), blood samples were drawn from 20 chickens from two different farms neighboring a horse - riding center in december 2002. the survey on horses was planned to be as exhaustive as possible in guadeloupe and the nearby island of marie galante (6115-1555). serum samples from 360 of 400 horses thought to live in guadeloupe were collected in july 2002 (figure). in locations where positive horses were detected during the first survey, another sampling was drawn from horses from december 2002 to january 2003 to measure the rate of serologic conversion and the incidence of the infection. insert : locations of horse and chicken sampling places in guadeloupe and marie galante islands. red triangle, farm with seropositive chicken ; blue circle, equine center with seropositive horses identified from july 2002 ; gold circle, equine center with seropositive horses identified from december 2002 to january 2003 ; black circle, equine center with no seropositive horses. enzyme - linked immunosorbent assays (elisa) were performed to detect specific immunoglobulin (ig) g antibodies to wnv in horses, ducks, geese, and chickens. additional immunocapture igm elisa was performed on horses positive for wnv by igg elisa (8). most positive serum samples were tested by plaque reduction neutralization test (prnt 80) for both wnv and st. all the birds (36 ducks, 14 geese, and 3 gulls) sampled from five farms and one pond in st. maarten at the end of july 2002 tested negative for wnv by igg elisa (the elisa test for the gulls has not been validated). in july 2002, 10 of 360 horses tested positive for wnv by igg elisa, and 2 of them were also positive by igm elisa. seropositive horses were located in four different places, two in guadeloupe and two in marie galante. the results of the survey undertaken in december 2002 to january 2003 in equine centers where positive animals were detected in july 2002 indicated a high rate of wnv seroconversion in horses in these locations (table 1). in july 2002, the overall wnv prevalence rate (igg elisa) was 2.8%, reaching 10.4% in places where infected horses were found (locations a, b, c, d). in january 2003, in these and related places (where some horses were moved from the former areas in july 2002), the prevalence rate increased to 50%. on paired samples, 54 of 114 horses that tested negative in july 2002 were positive in january 2003. the incidence rate calculated for the places where outbreaks were noticed (a to i) is 7.9% per month. in december 2002 and january 2003 chickens were collected from two backyards (10 chickens in each place) neighboring one horse - riding club where positive animals were detected. eleven of these chickens tested positive by igg elisa in december 2002. to confirm the specificity of the results, positive horses samples were tested by prnt against wnv and slev ; all the animals showed a higher titer for wnv than for slev (table 2). the serologic survey conducted on horses indicated an active focus of wnv infection in guadeloupe, probably linked to the first infestation of the archipelago by the virus. the absence of igm antibodies in horses at the end of 2002 indicates that the seroconversions did not occur during the last weeks of the year but earlier. these results (i.e., the presence of igm antibodies in 2 of 10 positive animals in july 2002) suggest that the first wmv infections in horses probably occurred during the first 6 months of 2002 and spread in the equine population in the middle of the year. when birds migrate, they cross the lesser antilles (6). a migratory bird, infected before leaving north america or the caribbean islands, may develop viremia when reaching st. martin, marie galante, or guadeloupe islands and transmit the virus to mosquito vectors during the resting period. migratory birds from the north usually arrive in guadeloupe later than july ; thus, the infection observed in horses in july 2002 was probably not derived from migrating birds that year. after one or more introductions, the virus may have gradually spread in the local vector populations and amplified in resident birds even over the winter, when vectors are still active in the caribbean. then, 6 months later, the virus spread to susceptible species (horses), in which it was first detected. in guadeloupe, both animal and human surveillance systems have been set up and are interacting to detect virus circulation. in that respect, the surveillance of susceptible animal species can provide important indicators for the possible appearance of the disease in humans. as shown in the united states, the death of wild birds is a pertinent indicator for human risk (9). in avian species, mortality and sentinel surveillance this could be related to the absence in guadeloupe of species known to be extremely susceptible to the infection (corvidae), vector competence, or the virus strain. a random survey is being implemented on domestic birds to assess the geographic distribution of the infection, in june through july 2003 (beginning of the rainy season), when populations of vectors increase markedly in guadeloupe. a new serologic prevalence survey in horses is also in process, and clinical surveillance is ongoing. despite a high rate of wnv - seropositive animals, no clinical disease has been observed. this situation could be related to the virus titer, the rate of infected vectors (which could be too low during the first year after wnv is introduced), or the virus strain. in 2003, mosquito surveillance was implemented in places where deaths in birds or encephalitis cases in horses were observed. virus detection using reverse transcription polymerase chain reaction will be used in our laboratory to test dead birds and pools of mosquitoes. these surveys are intended to provide the public health services with distribution and prevalence maps. | to determine whether west nile virus (wnv) had reached the archipelago of guadeloupe, a serologic study in horses and birds was conducted in 2002. immunoglobulin (ig) g, igm, enzyme - linked immunosorbent assay, and seroneutralization tests identified wnv infection in horses and chickens. six months later, a high rate of seroconversion was observed in horses. |
between 2003 and 2006, 44 patients with ifnfs were diagnosed and treated with mp at an institution. among the 44 patients, 10 who were followed for 10 mm on postoperative radiographs influenced re - displacement and non - union after surgery. at the same time, shimizu.10) standardized the atd by the diameter of the unaffected femoral head to minimize the effect of the difference in the patients ' body sizes. shimizu.10) measured the capital impaction index as a new indicator of an impacted fracture with excessive shortening at the fracture site and showed that the degree of capital impaction was significantly associated with unsuccessful outcomes when the capital impaction index was greater than the mean plus the standard deviation. we also used the value of the atd to measure the degree of impaction of fractures, but there were several differences between the aforementioned studies and the current study. first, the atd was standardized by the atd of the unaffected side instead of the unaffected femoral head, not only to minimize the effect of the difference in the patients ' body sizes, but also to adjust for errors from the difference in hip position. with a slight flexion of the hip, the atd of the affected side will be measured as erroneously decreased, but might be adjusted by using the atd index (the atd of the affected side / the atd of the unaffected side) because both legs are usually in the same position. second, we evaluated the progression of impaction of fractures by measuring the percentage decrease in the atd index using sequential radiographs. there are some limitations to the use of a single value of the atd because it can not be applied in varus - type impacted fractures and can not be used in case of the paradoxical increase of the atd in valgus - type fractures (fig. are always decreased more than valgus - type fractures with the same degree of impaction and measurement of schimizu 's capital impaction index may be exaggerated, even with a small degree of impaction.10) third, we demonstrated increased progression of impaction at the fracture site within 3 months after surgery is significantly related with a poor outcome. calandruccio and anderson27) reported that in non - displaced and impacted fractures, the main damage is to the vessels in the bone at the level of the fracture, whereas in displaced fractures, there may also be varying degrees of damage to the retinacular vessels. the progressive impaction or collapse of the femoral head may produce further damage to the retinacular vessels and this might be the basis for poor clinical outcomes associated with more progression of impaction in the current study. fourth, the patients in this study were followed for a longer period of time (mean, 3.4 years ; range, 2.2 to 5.9 years) than in previous studies. all data were collected and analyzed retrospectively, and the number of patients was small. further studies with a larger sample size is needed to confirm the association of the progression of impaction at the fracture site with poor clinical outcome and to ascertain the statistical difference of the clinical outcome between valgus and varus ifnfs. in conclusion, primary stabilization with knowles pins for impacted femoral neck fractures resulted in reasonable clinical outcomes with low morbidity. although there was a significant difference of a mean percentage decrease in the atd index between the group that was not treated successfully and the group that was treated successfully, we could not verify it as a risk factor for failure of treatment because the odds ratio was not statistically significant. | backgroundwe evaluated the clinical and radiologic results of impacted femoral neck fractures treated with multiple pinning and determined the influence of the progression of impaction at the fracture site on clinical outcome.methodsthere were 34 patients with a mean age of 65.5 years. the mean follow - up period was 3.4 years. progression of fracture site impaction was measured using an articulo - trochanteric distance index and the percentage decrease in the articulo - trochanteric distance index between follow - up intervals. the failure of treatment was clarified as non - union and avascular necrosis. other characteristics of the patients, including mean waiting time for surgery, preoperative singh index score, and body mass index, were also measured to evaluate the influence on the clinical outcome of surgery.resultsthere were 6 fractures which were not treated successfully (3 non - union, 8.8% and 3 avascular necrosis, 8.8%). the mean percentage decrease of the articulo - trochanteric distance index within the first 6 weeks after surgery was 4.5% in the successful group and 25.1% in the failure group (p < 0.001). there was also a significant mean percentage decrease in the articulo - trochanteric distance index between 6 weeks and 3 months (p < 0.001).conclusionsprimary stabilization with knowles pins for impacted femoral neck fractures had a reasonable clinical outcome with low morbidity. despite a significant difference of a mean percentage decrease in the articulo - trochanteric distance index between the successful group and the failure group, we could not verify it as a risk factor for failure of treatment because the odds ratio was not statistically significant. |
cancer is primarily characterized by the uncontrolled proliferation of cells and their ability to metastasize. in spite of significant advances in the fight against cancer, it remains a challenging medical problem. however, toxicity is a major side effect, which limits the utility and effectiveness of such nontargeted chemotherapeutics. recent research in the development of drug delivery systems has focused on targeted delivery and controlled drug release at tumor sites in order to increase efficacy while reducing systemic toxicity. imaging - guided drug delivery is considered a promising strategy to achieve this goal.1 full implementation of imaging - guided drug delivery will require that drugs can be imaged or identified in the body as they enter the blood stream. the goal of imaging - guided drug delivery is to optimize local delivery of the therapeutic pharmaceutical agent to the target tissue and provide microanatomical and functional imaging feedback of the therapeutic process, as well as longitudinal treatment and monitoring. the explosive growth of biocompatible nanotechnologies has made the clinical utilization of molecular imaging and therapy with a host of novel agents a realistic near - term possibility. various nanocarriers, such as superparamagnetic iron oxide nanoparticles,2,3 gold nanoparticles,4 liposomes,5 and polymeric nanoparticles6 loaded with large payloads of imaging agents, enable detection of cancer with standard imaging equipment via passive or active tumor - targeting effects. in order to fulfill the goal of imaging - guided drug delivery, nanocarriers need to be multifunctional, thus making them useful for both imaging and drug delivery. our group has developed a well - defined and biocompatible amphiphilic telodendrimer system composed of polyethylene glycol (peg), cholic acid, and a dendritic lysine core that can self - assemble into multifunctional water - soluble nanomicelles to enable efficient delivery of hydrophobic cargos such as paclitaxel and the hydrophobic dye, 1,1-dioctadecyl-3,3,3,3-tetramethylindodicarbocyanine perchlorate.7,8 telodendrimers are easily labeled with fluorophores and radionuclides by covalent conjugation onto a lysine side chain at the junction site between the peg and the cholic acid cluster, without compromising their propensity to form nanomicelles. for noncovalent labeling, telodendrimers can be mixed with radio - labeled drugs or fluorescent probes during nanomicelle formation.7 the tailored multifunctional features of the telodendrimer - based nanomicelle system are ideal for imaging - guided drug delivery applications. previous reports7,8 have demonstrated efficient tumor targeting and drug delivery by nanomicelles through optical imaging and efficacy studies using ovarian cancer xenograft models. our nanomicelles were prepared via self - assembly of telodendrimers containing a linear 5 kda peg covalently attached to a dendritic lysine core with eight cholic acid groups (pegca8). in order to characterize and quantitatively analyze the biodistribution and tumor targeting effect of nanomicelle nanocarriers further, the telodendrimer was radiolabeled with i using the bolton - hunter reagent, which allowed in vivo microspect / ct imaging studies. in separate experiments, c - labeled paclitaxel (c - ptx) was loaded into the nanomicelles (c - ptx - nm) and administered to mice bearing tumors in order to elucidate the tumor - targeting, biodistribution, and pharmacokinetic profiles of the drug cargo sequestered in the nanocarrier. comparison of both the imaging and quantitative biodistribution profiles of paclitaxel loaded into nanomicelles will aid in understanding and optimizing the telodendrimer system for better targeting of systemic cancer therapies. c - ptx was purchased from moravek biochemicals inc, (brea, ca). a cremophor el formulation of paclitaxel (taxol) from ak scientific (mountain view, ca) was obtained from the uc davis cancer center pharmacy. ovarian cancer (skov-3) cell line was obtained from the american type culture collection (manassas, va). the animal studies were performed according to a protocol approved by the institutional animal care and use committee of the university of california, davis. female athymic nude mice (nu / nu), obtained from harlan inc, (indianapolis, in) at 56 weeks of age, were injected subcutaneously in the right flank with 5 10 skov-3 cells suspended in 200 l of phosphate - buffered saline. when the subcutaneous tumors reached 0.51.0 cm in diameter or 1421 days after implantation, the tumor - bearing mice were subjected to microspect / ct imaging of the i - labeled nanomicelles or biodistribution studies of the c - ptx loaded nanomicelles. iodination of telodendrimers was accomplished via the i - bolton - hunter reagent, which was provided by perkins elmer through custom radiolabeling. excess bolton - hunter reagent was removed by passage through an lh-20 size exclusive column using ethanol as the eluent, yielding 10 mci of i - labeled telodendrimers with a radioactive purity of 99.1%. preparation of the paclitaxel - loaded i - labeled nanomicelles (ptx - i - nm) was as follows : 3.2 mg of paclitaxel and 32 mg of pegca8 telodendrimer were dissolved in 2 ml of chloroform. immediately after mixing, 0.8 mci of i - labeled pegca8 solution in ethanol (0.32 ml) phosphate - buffered saline 1.6 ml was added and the mixture was vortexed for 30 seconds and sonicated for 30 minutes to disperse the complex into micelles. the ratio of i - labeled to unlabeled pegca8 in the paclitaxel - loaded nanomicelles was 1:800 by mass. microspect / ct imaging of ptx - i - nm in a human ovarian cancer xenograft model was performed at the center for molecular and genomic imaging, university of california, davis. nude mice bearing skov-3 xenografts were injected with 200 l of 100 ci paclitaxel - loaded ptx - i - nm (400 g of paclitaxel in 4 mg of pegca8) via the tail vein. pinhole spect images were acquired at hours 1, 5, 18, 24, 48, 72, and 94 following injection. spect images were acquired using the inveonmm (siemens preclinical solutions, knoxville, tn). the collimator set used was the mouse medium energy collimator, which is a single pinhole with a 3 mm diameter. a total of 20 projections were acquired over 180 degrees per spect head and the initial projection exposure time was 150 seconds. the exposure time at each projection is adjusted for nuclide decay to yield an equivalent number of counts per projection. list mode data are collected, including all photon events, and photon energy is recorded. the micelles were formulated in a manner similar to the protocol used above, except without i - labeling. briefly, 4 ci of c - ptx in ethyl acetate was added to 5 ml of chloroform solution containing 15 mg of unlabeled paclitaxel and 100 mg of pegca8 telodendrimer. the solution was dried by nitrogen blowing overnight, followed by addition of 5 ml of phosphate - buffered saline and vortex mixing for 30 seconds and sonication for 30 minutes. the ratio of radiocarbon - labeled and unlabeled paclitaxel in the resulting micelle formulation was approximately 1:1100 by mass. doping of taxol with c - ptx (c - ptx - taxol) was achieved as follows : 3 ci of c - ptx in ethyl acetate was added to 1.875 ml of taxol (6 mg paclitaxel / ml) and vortexed for 30 seconds. the cremophor solution of taxol was then diluted with phosphate - buffered saline to a final paclitaxel concentration of 1.5 mg / ml. the ratio of radiocarbon - labeled and unlabeled paclitaxel in the resulting micelles was approximately 1:1100 by mass. nude mice bearing skov-3 xenografts were injected with 200 l solutions containing of 100 ci c - ptx - nm (400 g total mass of paclitaxel that was mixed with 4 mg of pegca8 prior to nanomicelle synthesis) via the tail vein. the major organs and tissues collected were whole blood, brain, skin, heart, lung, liver, spleen, kidney, bladder, muscle, and tumor. the time points of data collection were at hours 0, 0.5, 1, 6, 16, 24, 48, and 72. at selected time points, all organs were collected and weighed, put into 1.5 ml eppendorf centrifuge tubes, and kept on ice prior to homogenization. the minced tissue was then added to 1 ml of biosol, agitated gently, and placed in an incubator shaker at 50c and shaken for 6 hours at 650 rpm. when chunks of tissue were no longer visible in the suspension, all the solution in the tubes were transferred into 20 ml scintillation vials, and decolorized by addition of 0.2 ml of 30% hydrogen peroxide. finally, 18 ml of liquid scintillation counting cocktail was added into each scintillation vial, followed by running the samples in a packard 1500 tri - carb liquid scintillation analyzer with standard protocols for radiocarbon detection. data were processed on an excel spreadsheet running solutions pharmacokinetic software. for determination of the radiointensity of tumors and normal organs in the radioimaging, we calculated the average values of the tumor area and of the normal organ area using the three - dimensional regions of interest function of the siemens micropet asipro wm 6.7.1.2 software program. the student s t - test was used for statistical analysis of the radioimaging intensity and pharmacokinetic data. c - ptx was purchased from moravek biochemicals inc, (brea, ca). a cremophor el formulation of paclitaxel (taxol) from ak scientific (mountain view, ca) was obtained from the uc davis cancer center pharmacy. ovarian cancer (skov-3) cell line was obtained from the american type culture collection (manassas, va). the animal studies were performed according to a protocol approved by the institutional animal care and use committee of the university of california, davis. female athymic nude mice (nu / nu), obtained from harlan inc, (indianapolis, in) at 56 weeks of age, were injected subcutaneously in the right flank with 5 10 skov-3 cells suspended in 200 l of phosphate - buffered saline. when the subcutaneous tumors reached 0.51.0 cm in diameter or 1421 days after implantation, the tumor - bearing mice were subjected to microspect / ct imaging of the i - labeled nanomicelles or biodistribution studies of the c - ptx loaded nanomicelles. iodination of telodendrimers was accomplished via the i - bolton - hunter reagent, which was provided by perkins elmer through custom radiolabeling. excess bolton - hunter reagent was removed by passage through an lh-20 size exclusive column using ethanol as the eluent, yielding 10 mci of i - labeled telodendrimers with a radioactive purity of 99.1%. preparation of the paclitaxel - loaded i - labeled nanomicelles (ptx - i - nm) was as follows : 3.2 mg of paclitaxel and 32 mg of pegca8 telodendrimer were dissolved in 2 ml of chloroform. immediately after mixing, 0.8 mci of i - labeled pegca8 solution in ethanol (0.32 ml) phosphate - buffered saline 1.6 ml was added and the mixture was vortexed for 30 seconds and sonicated for 30 minutes to disperse the complex into micelles. the ratio of i - labeled to unlabeled pegca8 in the paclitaxel - loaded nanomicelles was 1:800 by mass. microspect / ct imaging of ptx - i - nm in a human ovarian cancer xenograft model was performed at the center for molecular and genomic imaging, university of california, davis. nude mice bearing skov-3 xenografts were injected with 200 l of 100 ci paclitaxel - loaded ptx - i - nm (400 g of paclitaxel in 4 mg of pegca8) via the tail vein. pinhole spect images were acquired at hours 1, 5, 18, 24, 48, 72, and 94 following injection. spect images were acquired using the inveonmm (siemens preclinical solutions, knoxville, tn). the collimator set used was the mouse medium energy collimator, which is a single pinhole with a 3 mm diameter. a total of 20 projections were acquired over 180 degrees per spect head and the initial projection exposure time was 150 seconds. the exposure time at each projection is adjusted for nuclide decay to yield an equivalent number of counts per projection. list mode data are collected, including all photon events, and photon energy is recorded. the micelles were formulated in a manner similar to the protocol used above, except without i - labeling. briefly, 4 ci of c - ptx in ethyl acetate was added to 5 ml of chloroform solution containing 15 mg of unlabeled paclitaxel and 100 mg of pegca8 telodendrimer. the solution was dried by nitrogen blowing overnight, followed by addition of 5 ml of phosphate - buffered saline and vortex mixing for 30 seconds and sonication for 30 minutes. the ratio of radiocarbon - labeled and unlabeled paclitaxel in the resulting micelle formulation was approximately 1:1100 by mass. doping of taxol with c - ptx (c - ptx - taxol) was achieved as follows : 3 ci of c - ptx in ethyl acetate was added to 1.875 ml of taxol (6 mg paclitaxel / ml) and vortexed for 30 seconds. the cremophor solution of taxol was then diluted with phosphate - buffered saline to a final paclitaxel concentration of 1.5 mg / ml. the ratio of radiocarbon - labeled and unlabeled paclitaxel in the resulting micelles was approximately 1:1100 by mass. nude mice bearing skov-3 xenografts were injected with 200 l solutions containing of 100 ci c - ptx - nm (400 g total mass of paclitaxel that was mixed with 4 mg of pegca8 prior to nanomicelle synthesis) via the tail vein. the major organs and tissues collected were whole blood, brain, skin, heart, lung, liver, spleen, kidney, bladder, muscle, and tumor. the time points of data collection were at hours 0, 0.5, 1, 6, 16, 24, 48, and 72. at selected time points, all organs were collected and weighed, put into 1.5 ml eppendorf centrifuge tubes, and kept on ice prior to homogenization. the minced tissue was then added to 1 ml of biosol, agitated gently, and placed in an incubator shaker at 50c and shaken for 6 hours at 650 rpm. when chunks of tissue were no longer visible in the suspension, all the solution in the tubes were transferred into 20 ml scintillation vials, and decolorized by addition of 0.2 ml of 30% hydrogen peroxide. finally, 18 ml of liquid scintillation counting cocktail was added into each scintillation vial, followed by running the samples in a packard 1500 tri - carb liquid scintillation analyzer with standard protocols for radiocarbon detection. for determination of the radiointensity of tumors and normal organs in the radioimaging, we calculated the average values of the tumor area and of the normal organ area using the three - dimensional regions of interest function of the siemens micropet asipro wm 6.7.1.2 software program. the student s t - test was used for statistical analysis of the radioimaging intensity and pharmacokinetic data. our previous research has demonstrated excellent tumor targeting of telodendrimer - based nanomicelles using near infrared fluorescence imaging, whereby nanomicelles formed by pegca8 are loaded with the near - infrared dye, 1,1-dioctadecyl-3,3,3,3-tetramethyl indodicarbocyanine perchlorate, and paclitaxel.7,8 near - infrared fluorescence imaging offers unique advantages for diagnostic imaging of solid tumors with high sensitivity,9 given the low in vivo autofluorescence in the near - infrared range (700900 nm) and the minimal near - infrared absorbance by biological components, such as hemoglobin, water, and lipids.10,11 however, near - infrared fluorescence imaging is not quantitative and has a limited penetration distance, as well as low spatial resolution.12 in contrast, radioimaging is superior for quantification due to good tissue penetration of gamma rays and the ability to measure count rates in tissue accurately, permitting whole body quantitative imaging not only in small animals, but also in humans. for this report, the pegca8 telodendrimer was labeled with i via the bolton - hunter reagent as shown in scheme 1a. the unbound labeling reagent was removed by passage through a size - exclusive column, with ethanol as the eluent to avoid formation of telodendrimer aggregates in which the iodination reagent could become trapped. the i - labeled telodendrimer was doped into a solution of unlabeled telodendrimers and loaded with paclitaxel during self - assembly according to a previously published protocol.7,8 doses of ptx - i - labeled nanomicelles were injected into nude mice bearing skov-3 xenografts. as shown in figure 1, decay - corrected imaging indicated that the ptx - i - nm accumulated specifically and continuously at the tumor site and reached a peak at around 1824 hours post injection. the tumor signal then decreased gradually, with substantial retention of nanomicelles in the tumor with respect to background tissue for up to 94 hours post injection. within the first 5 hours, the majority of the i - labeled material was observed in the blood circulation of the mouse and in the blood - rich organs of the chest and upper abdomen. the signal within normal organs, such as the heart, lung, and liver, was dramatically higher than that in tumor tissue. for 1824 hours post injection, the signal in the tumor tissue was significantly (p < 0.05) higher than in most of the rest of body. forty - eight hours post injection, significant retention of ptx - i - nm persisted at the tumor site. whole body projection images (figure 2) showed the tumor to be the brightest part of the whole body at 72 hours post injection. in general, the tumor - targeting profile demonstrated by radioimaging is consistent with previous results from optical imaging, in which the telodendrimer was fluorescently labeled with bodipy, a hydrophobic near - infrared dye.13 this finding supports previous observations that nanomicelles are able to target the tumor site via the enhanced permeability and retention effect associated with porous tumor vasculature, which enables nanomicelles to release their cargo into localized tumor regions. quantitative analysis of the imaging data was performed in order to study the distribution profiles of ptx - i - nm further in normal organs and tumor tissue. the radio signal in the blood pool refers to the signal calculated from the heart cavity. other normal organs, such as the liver, lung, and muscle, were analyzed in addition to tumor tissue. dominant i accumulation was shown in the blood pool, liver, and lung within 24 hours. distribution of i in the liver was much higher than that in tumor tissue for 5 hours post injection (figure 3a), which is probably due to the high content of blood in the liver. early accumulation in normal tissues, including muscle, had washed out quickly by one hour post injection. however, uptake in tumor tissue increased gradually and reached a plateau at 1824 hours, then decreased slowly. this contrast in accumulation between tumor and normal tissue is consistent with enhanced permeation and retention - mediated accumulation of nanomicelles in tumor tissue. the i signal in normal organs and tumor over time was normalized by the signal in muscle to reflect the relative distribution and kinetic profiles. the signal change in muscle is usually in response to the basic clearance profile of the injected ptx - i - nm. therefore, the signal in tumor tissue or organs normalized by the signal from muscle will subtract interference from the background to highlight accumulation and clearance trends of ptx - i - nm in tumor tissue or organs. the normalized results indicate that the blood pool / muscle ratio was higher than the ratios from other organs and tumor tissue within 24 hours, but decreased rapidly to the background level by 48 hours. the ratio of lung / muscle remained constant, reflecting the similar clearance profile of the i - labeled substance in lung and muscle. however, the ratio of tumor / muscle kept increasing over time, indicating gradual accumulation and much slower clearance of the nanoparticles from tumor tissue. the liver/ muscle ratio slightly increased over time, probably owing to the reticuloendothelial system in the liver that continuously takes up the i - labeled materials remaining in the body (figure 3b). an understanding of the fate and biological effects of nanoparticles in animals is critical to their medical applications in vivo. pharmacokinetic and organ / tissue distribution properties of nanoparticles are of great interest from the clinical point of view because of their potential uses in cancer imaging and therapy. systematic studies are required to evaluate the distribution of administered nanoparticles inside the body, especially at the tumor site, after injection. the use of c - ptx enabled us to quantify the drug and its metabolites within the mouse tissue and organs accurately via liquid scintillation counting after intravenous administration. because the predominant metabolites of paclitaxel include 3-p - hydroxypaclitaxel, 6-hydroxypaclitaxel, and 6,3-p - dihydroxypaclitaxel, without any metabolic loss of carbon atoms from the parent molecule, we assume that the radiocarbon measurements accounted for all of the parent paclitaxel and its metabolites present in each sample.14 in order to study the effects of formulation into nanomicelles on the distribution of paclitaxel, c - ptx was loaded into nanomicelles and injected into nude mice bearing skov-3 xenografts. as a benchmark for comparison, a small amount of c - ptx was added to taxol, a cremophor el formulation of paclitaxel used in the clinic, which was also administered to the tumor - bearing mice. the c concentration in blood and tissues was determined by liquid scintillation counting, which allowed calculation of total paclitaxel using the specific activity of each dose as a conversion factor. as shown in figure 4, the biodistribution profiles of the c - ptx - nm in different organs and tumor tissue were similar to that of c - ptx - taxol. both formulations showed low brain uptake of paclitaxel, indicating a general lack of accessibility because of the blood - brain barrier. at the zero time point, blood was withdrawn by heart puncture within one minute of intravenous injection of the c - labeled drug formulation. organs and tumor tissue were harvested immediately after euthanasia. figure 4a shows that c uptake in most of the organs reach a maximum within minutes, followed by rapid washout of drug, as was observed in the i experiments. in contrast, the concentration of paclitaxel and its metabolites showed slower accumulation in tumor tissue, and reached a peak at around 30 minutes post injection, which then decreased slowly compared with normal tissues. the paclitaxel concentration in tumors of animals treated with the telodendrimer nanomicelle formulation was significantly (p < 0.05) higher than that in other organs, even in the liver, after 24 hours, which is consistent with the microspect/ ct imaging results. tumor uptake in animals treated with c - ptx - taxol was also observed to increase within the first hour and to decrease gradually to a level similar to that in other organs, including skin, lung, and liver (figure 4b). it is known that taxol, which is a cremophor el (surfactant) formulation of paclitaxel, can also form micelles of about 10 nm in size upon dilution in water or biological fluids. therefore, taxol also has a relatively long circulation time and is able to target tumor tissue via the enhanced permeation and retention effect. the biodistribution of taxol in rodents has been described in tumor - bearing mice before. liver and tumor have shown high paclitaxel concentrations at 24 hours after administration.15 similar distribution behavior has also been observed with in - labeled paclitaxel.16 however, the stability of paclitaxel dissolved in cremophor el is poor in vitro upon dilution, as shown in our experiments. paclitaxel has a tendency to leak out from the cremophor micelles, and crystals of paclitaxel were observed in the diluted taxol solution (20 dilution by phosphate - buffered saline), whereas the telodendrimer nanomicelles loaded with paclitaxel at the same dilution remained very stable in size and solubility over months. to demonstrate the relative trend of c - ptx uptake in different organs and tumor tissue, all values were normalized to muscle c levels for each time point, except in blood (figure 5). most organ ratios displayed continuously decreasing radiocarbon ratios, except for skin, elimination from which was slow compared with muscle, which is consistent with the high lipophilicity of paclitaxel. for c - ptx - nm, the tumor / muscle ratio of radiocarbon content kept increasing and reached a plateau at approximately 8.5-fold 2448 hours post injection. however, the normalized tumor / muscle ratio of c - ptx - taxol showed an increase of only 3.5-fold at the highest point (figure 5b), which is much lower than that when c - ptx was loaded in nanomicelles. furthermore, the ratio of tumor/ muscle (c - ptx - taxol) was even lower than that of the skin / muscle ratio at earlier time points at least 24 hours post injection (figure 5b). the whole blood pharmacokinetic profile of paclitaxel after administration of c - ptx - nm or c - ptx - taxol at dose levels of 15 mg / kg was calculated using a one - compartment model (figure 6). a t = 0 time point was used to determine the maximum concentration of paclitaxel, which was 55 g / ml for nanomicelles and 21 g / ml for taxol. the calculated initial absorption / distribution (t1/2) and terminal (t1/2) half - lives were 1.9 hours and 70 hours, respectively, for nanomicelles, and 3.1 hours and 47 hours, respectively, for taxol (table 1). the area under the blood concentration - time curve for the nanomicelles was similar to that for taxol (21.8 g - hours / ml and 18.3 g - hours / ml, respectively). the blood half - lives for taxol were similar to values reported for nude mice, except for the terminal half - life, which was previously reported to be 17 hours in plasma.17 the long terminal half - lives for both formulations in this report are consistent with paclitaxel uptake into blood cells, which is not accounted for in typical plasma or serum pharmacokinetic data. although the initial whole blood absorption and distribution kinetics were faster for taxol, the nanomicelle formulation persisted at higher concentrations at the later time points, possibly accounting, in part, for its improved preclinical efficacy.7,1820 the longer half - life of ptx - nm compared with taxol is consistent with slower hepatic elimination as a consequence of the 10100 nm size of the nanomicelle nanocarrier.8 the slower blood terminal half - life observed for the nanomicelles is consistent with the slower hepatic filtration of the nanoparticle formulation, which has been previously reported for other nanoparticle - mediated drug delivery systems.21,22 the paclitaxel clearance of 805 l / hour / kg for the taxol formulation was reduced to 687 l / hour / kg for the ptx - nm formulation. despite the fact that higher blood levels are reached when paclitaxel is given in the taxol formulation, the tissue levels were essentially similar for both of the tested drug preparations. it has to be noted that two different radiolabeling strategies were used in this research, in which the radio isotope i was conjugated to telodendrimers for the spect imaging study and c - ptx was loaded inside nanomicelles for the pharmacokinetic experiments. there was a high radioactive signal found in the bloodstream during the first 24 hours in the microspect / ct images (figures 1 and 3a). however, in the pharmacokinetic study, c - ptx - nm showed much less accumulation in the bloodstream than in the rest of the body, except for muscle, even within one minute post injection (figure 4a). one explanation for this is that the current nanomicelle formulation is not stable in blood and that the nanomicelles disassemble partially and the loaded drug begins to release from the nanomicelles immediately after in vivo administration and diffusion into normal organs, resulting in a rapid decrease of c - ptx in the circulation.23,24 in contrast, the i - telodendrimers, even if coming from dissociated nanomicelles, still remain in the blood circulation for a longer time, contributing to a much higher radioactive signal in the blood during the 24 hours post injection. we recently reported on the development of disulfide or boronate - catechol cross - linked nanomicelles23,24 that are much more stable than the non - crosslinked micelles reported here. the main advantage of crosslinked micelles is that premature drug release in the circulation can be minimized. furthermore, disulfide reduction can occur inside the tumor cells with high glutathione levels, or on demand with exogenously administered n - acetyl cysteine, a us food and drug administration approved reducing agent. similarly, the bornate catechol crosslinkages can be reversed with the acidic environment at the tumor site and inside the endosomes of the tumor cells, or with exogenously administered mannitol, an approved diuretic. as a result, such crosslinked nanomicelles may be therapeutically more efficacious than non - crosslinked micelles.23,24 work is underway in our laboratory using the techniques described in this study to determine the biodistribution and pharmacokinetics of such crosslinked nanomicelles. our previous research has demonstrated excellent tumor targeting of telodendrimer - based nanomicelles using near infrared fluorescence imaging, whereby nanomicelles formed by pegca8 are loaded with the near - infrared dye, 1,1-dioctadecyl-3,3,3,3-tetramethyl indodicarbocyanine perchlorate, and paclitaxel.7,8 near - infrared fluorescence imaging offers unique advantages for diagnostic imaging of solid tumors with high sensitivity,9 given the low in vivo autofluorescence in the near - infrared range (700900 nm) and the minimal near - infrared absorbance by biological components, such as hemoglobin, water, and lipids.10,11 however, near - infrared fluorescence imaging is not quantitative and has a limited penetration distance, as well as low spatial resolution.12 in contrast, radioimaging is superior for quantification due to good tissue penetration of gamma rays and the ability to measure count rates in tissue accurately, permitting whole body quantitative imaging not only in small animals, but also in humans. for this report, the pegca8 telodendrimer was labeled with i via the bolton - hunter reagent as shown in scheme 1a. the unbound labeling reagent was removed by passage through a size - exclusive column, with ethanol as the eluent to avoid formation of telodendrimer aggregates in which the iodination reagent could become trapped. the i - labeled telodendrimer was doped into a solution of unlabeled telodendrimers and loaded with paclitaxel during self - assembly according to a previously published protocol.7,8 doses of ptx - i - labeled nanomicelles were injected into nude mice bearing skov-3 xenografts. as shown in figure 1, decay - corrected imaging indicated that the ptx - i - nm accumulated specifically and continuously at the tumor site and reached a peak at around 1824 hours post injection. the tumor signal then decreased gradually, with substantial retention of nanomicelles in the tumor with respect to background tissue for up to 94 hours post injection. within the first 5 hours, the majority of the i - labeled material was observed in the blood circulation of the mouse and in the blood - rich organs of the chest and upper abdomen. the signal within normal organs, such as the heart, lung, and liver, was dramatically higher than that in tumor tissue. for 1824 hours post injection, the signal in the tumor tissue was significantly (p < 0.05) higher than in most of the rest of body. forty - eight hours post injection, significant retention of ptx - i - nm persisted at the tumor site. whole body projection images (figure 2) showed the tumor to be the brightest part of the whole body at 72 hours post injection. in general, the tumor - targeting profile demonstrated by radioimaging is consistent with previous results from optical imaging, in which the telodendrimer was fluorescently labeled with bodipy, a hydrophobic near - infrared dye.13 this finding supports previous observations that nanomicelles are able to target the tumor site via the enhanced permeability and retention effect associated with porous tumor vasculature, which enables nanomicelles to release their cargo into localized tumor regions. quantitative analysis of the imaging data was performed in order to study the distribution profiles of ptx - i - nm further in normal organs and tumor tissue. the radio signal in the blood pool refers to the signal calculated from the heart cavity. other normal organs, such as the liver, lung, and muscle, were analyzed in addition to tumor tissue. dominant i accumulation was shown in the blood pool, liver, and lung within 24 hours. distribution of i in the liver was much higher than that in tumor tissue for 5 hours post injection (figure 3a), which is probably due to the high content of blood in the liver. early accumulation in normal tissues, including muscle, had washed out quickly by one hour post injection. however, uptake in tumor tissue increased gradually and reached a plateau at 1824 hours, then decreased slowly. this contrast in accumulation between tumor and normal tissue is consistent with enhanced permeation and retention - mediated accumulation of nanomicelles in tumor tissue. the i signal in normal organs and tumor over time was normalized by the signal in muscle to reflect the relative distribution and kinetic profiles. the signal change in muscle is usually in response to the basic clearance profile of the injected ptx - i - nm. therefore, the signal in tumor tissue or organs normalized by the signal from muscle will subtract interference from the background to highlight accumulation and clearance trends of ptx - i - nm in tumor tissue or organs. the normalized results indicate that the blood pool / muscle ratio was higher than the ratios from other organs and tumor tissue within 24 hours, but decreased rapidly to the background level by 48 hours. the ratio of lung / muscle remained constant, reflecting the similar clearance profile of the i - labeled substance in lung and muscle. however, the ratio of tumor / muscle kept increasing over time, indicating gradual accumulation and much slower clearance of the nanoparticles from tumor tissue. the liver/ muscle ratio slightly increased over time, probably owing to the reticuloendothelial system in the liver that continuously takes up the i - labeled materials remaining in the body (figure 3b). an understanding of the fate and biological effects of nanoparticles in animals is critical to their medical applications in vivo. pharmacokinetic and organ / tissue distribution properties of nanoparticles are of great interest from the clinical point of view because of their potential uses in cancer imaging and therapy. systematic studies are required to evaluate the distribution of administered nanoparticles inside the body, especially at the tumor site, after injection. the use of c - ptx enabled us to quantify the drug and its metabolites within the mouse tissue and organs accurately via liquid scintillation counting after intravenous administration. because the predominant metabolites of paclitaxel include 3-p - hydroxypaclitaxel, 6-hydroxypaclitaxel, and 6,3-p - dihydroxypaclitaxel, without any metabolic loss of carbon atoms from the parent molecule, we assume that the radiocarbon measurements accounted for all of the parent paclitaxel and its metabolites present in each sample.14 in order to study the effects of formulation into nanomicelles on the distribution of paclitaxel, c - ptx was loaded into nanomicelles and injected into nude mice bearing skov-3 xenografts. as a benchmark for comparison, a small amount of c - ptx was added to taxol, a cremophor el formulation of paclitaxel used in the clinic, which was also administered to the tumor - bearing mice. the tissues and organs were harvested at various time points after injection. the c concentration in blood and tissues was determined by liquid scintillation counting, which allowed calculation of total paclitaxel using the specific activity of each dose as a conversion factor. as shown in figure 4, the biodistribution profiles of the c - ptx - nm in different organs and tumor tissue were similar to that of c - ptx - taxol. both formulations showed low brain uptake of paclitaxel, indicating a general lack of accessibility because of the blood - brain barrier. at the zero time point, blood was withdrawn by heart puncture within one minute of intravenous injection of the c - labeled drug formulation. figure 4a shows that c uptake in most of the organs reach a maximum within minutes, followed by rapid washout of drug, as was observed in the i experiments. in contrast, the concentration of paclitaxel and its metabolites showed slower accumulation in tumor tissue, and reached a peak at around 30 minutes post injection, which then decreased slowly compared with normal tissues. the paclitaxel concentration in tumors of animals treated with the telodendrimer nanomicelle formulation was significantly (p < 0.05) higher than that in other organs, even in the liver, after 24 hours, which is consistent with the microspect/ ct imaging results. tumor uptake in animals treated with c - ptx - taxol was also observed to increase within the first hour and to decrease gradually to a level similar to that in other organs, including skin, lung, and liver (figure 4b). it is known that taxol, which is a cremophor el (surfactant) formulation of paclitaxel, can also form micelles of about 10 nm in size upon dilution in water or biological fluids. therefore, taxol also has a relatively long circulation time and is able to target tumor tissue via the enhanced permeation and retention effect. the biodistribution of taxol in rodents has been described in tumor - bearing mice before. liver and tumor have shown high paclitaxel concentrations at 24 hours after administration.15 similar distribution behavior has also been observed with in - labeled paclitaxel.16 however, the stability of paclitaxel dissolved in cremophor el is poor in vitro upon dilution, as shown in our experiments. paclitaxel has a tendency to leak out from the cremophor micelles, and crystals of paclitaxel were observed in the diluted taxol solution (20 dilution by phosphate - buffered saline), whereas the telodendrimer nanomicelles loaded with paclitaxel at the same dilution remained very stable in size and solubility over months. to demonstrate the relative trend of c - ptx uptake in different organs and tumor tissue, all values were normalized to muscle c levels for each time point, except in blood (figure 5). most organ ratios displayed continuously decreasing radiocarbon ratios, except for skin, elimination from which was slow compared with muscle, which is consistent with the high lipophilicity of paclitaxel. for c - ptx - nm, the tumor / muscle ratio of radiocarbon content kept increasing and reached a plateau at approximately 8.5-fold 2448 hours post injection. however, the normalized tumor / muscle ratio of c - ptx - taxol showed an increase of only 3.5-fold at the highest point (figure 5b), which is much lower than that when c - ptx was loaded in nanomicelles. furthermore, the ratio of tumor/ muscle (c - ptx - taxol) was even lower than that of the skin / muscle ratio at earlier time points at least 24 hours post injection (figure 5b). the whole blood pharmacokinetic profile of paclitaxel after administration of c - ptx - nm or c - ptx - taxol at dose levels of 15 mg / kg was calculated using a one - compartment model (figure 6). a t = 0 time point was used to determine the maximum concentration of paclitaxel, which was 55 g / ml for nanomicelles and 21 g / ml for taxol. the calculated initial absorption / distribution (t1/2) and terminal (t1/2) half - lives were 1.9 hours and 70 hours, respectively, for nanomicelles, and 3.1 hours and 47 hours, respectively, for taxol (table 1). the area under the blood concentration - time curve for the nanomicelles was similar to that for taxol (21.8 g - hours / ml and 18.3 g - hours / ml, respectively). the blood half - lives for taxol were similar to values reported for nude mice, except for the terminal half - life, which was previously reported to be 17 hours in plasma.17 the long terminal half - lives for both formulations in this report are consistent with paclitaxel uptake into blood cells, which is not accounted for in typical plasma or serum pharmacokinetic data. although the initial whole blood absorption and distribution kinetics were faster for taxol, the nanomicelle formulation persisted at higher concentrations at the later time points, possibly accounting, in part, for its improved preclinical efficacy.7,1820 the longer half - life of ptx - nm compared with taxol is consistent with slower hepatic elimination as a consequence of the 10100 nm size of the nanomicelle nanocarrier.8 the slower blood terminal half - life observed for the nanomicelles is consistent with the slower hepatic filtration of the nanoparticle formulation, which has been previously reported for other nanoparticle - mediated drug delivery systems.21,22 the paclitaxel clearance of 805 l / hour / kg for the taxol formulation was reduced to 687 l / hour / kg for the ptx - nm formulation. despite the fact that higher blood levels are reached when paclitaxel is given in the taxol formulation, the tissue levels were essentially similar for both of the tested drug preparations. it has to be noted that two different radiolabeling strategies were used in this research, in which the radio isotope i was conjugated to telodendrimers for the spect imaging study and c - ptx was loaded inside nanomicelles for the pharmacokinetic experiments. there was a high radioactive signal found in the bloodstream during the first 24 hours in the microspect / ct images (figures 1 and 3a). however, in the pharmacokinetic study, c - ptx - nm showed much less accumulation in the bloodstream than in the rest of the body, except for muscle, even within one minute post injection (figure 4a). one explanation for this is that the current nanomicelle formulation is not stable in blood and that the nanomicelles disassemble partially and the loaded drug begins to release from the nanomicelles immediately after in vivo administration and diffusion into normal organs, resulting in a rapid decrease of c - ptx in the circulation.23,24 in contrast, the i - telodendrimers, even if coming from dissociated nanomicelles, still remain in the blood circulation for a longer time, contributing to a much higher radioactive signal in the blood during the 24 hours post injection. we recently reported on the development of disulfide or boronate - catechol cross - linked nanomicelles23,24 that are much more stable than the non - crosslinked micelles reported here. the main advantage of crosslinked micelles is that premature drug release in the circulation can be minimized. furthermore, disulfide reduction can occur inside the tumor cells with high glutathione levels, or on demand with exogenously administered n - acetyl cysteine, a us food and drug administration approved reducing agent. similarly, the bornate catechol crosslinkages can be reversed with the acidic environment at the tumor site and inside the endosomes of the tumor cells, or with exogenously administered mannitol, an approved diuretic. as a result, such crosslinked nanomicelles may be therapeutically more efficacious than non - crosslinked micelles.23,24 work is underway in our laboratory using the techniques described in this study to determine the biodistribution and pharmacokinetics of such crosslinked nanomicelles. the tumor - targeting properties of the telodendrimer pegca8 nanomicelle system have been previously demonstrated through near - infrared fluorescence optical imaging with improved preclinical outcomes compared with taxol and abraxane. microspect / ct imaging enabled by i - labeling of the nanomicelles further verified the highly efficient tumor targeting of the nanomicelles and provides a potential nanoplatform for cancer imaging and diagnosis. the biodistribution study of c - ptx indicates that sequestration of the drug in the pegca8 nanomicelle system markedly prolongs the paclitaxel circulation time in blood and improves the uptake of paclitaxel at the tumor site. the liver was the organ showing the highest uptake of paclitaxel at the beginning but the uptake had decreased rapidly to lower than tumor levels by 16 hours post injection. the results of radioimaging and biodistribution of the loaded drug support potential use of the pegca8 nm system as a promising nanocarrier for imaging - guided drug delivery. | backgrounda multifunctional telodendrimer - based micelle system was characterized for delivery of imaging and chemotherapy agents to mouse tumor xenografts. previous optical imaging studies demonstrated qualitatively that these classes of nanoparticles, called nanomicelles, preferentially accumulate at tumor sites in mice. the research reported herein describes the detailed quantitative imaging and biodistribution profiling of nanomicelles loaded with a cargo of paclitaxel.methodsthe telodendrimer was covalently labeled with 125i and the nanomicelles were loaded with 14c - paclitaxel, which allowed measurement of pharmacokinetics and biodistribution in the mice using microspect / ct imaging and liquid scintillation counting, respectively.resultsthe radio imaging data showed preferential accumulation of nanomicelles at the tumor site along with a slower clearance rate than paclitaxel formulated in cremophor el (taxol). liquid scintillation counting confirmed that 14c - labeled paclitaxel sequestered in nanomicelles had increased uptake by tumor tissue and slower pharmacokinetics than taxol.conclusionoverall, the results indicate that nanomicelle - formulated paclitaxel is a potentially superior formulation compared with taxol in terms of water solubility, pharmacokinetics, and tumor accumulation, and may be clinically useful for both tumor imaging and improved chemotherapy applications. |
g - protein coupled receptors (gpcrs) represent one of the most important classes of drug targets for pharmaceutical industry and play important roles in cellular signal transduction as cell surface receptor proteins 1., 2.. a gpcr only has a single polypeptide that consists of seven transmembrane -helices, three extracellular and three intracellular loops connecting the transmembrane domains. the n - terminal of the polypeptide is located on the extracellular side and the c - terminal extends to the cytoplasm. gpcrs can be activated by various extracellular signaling molecules that bind to the receptors and trigger their conformational changes. the activated receptors will then couple with g - proteins (gi / o, gq/11, gs, and g12/13) and further activate different signaling pathways (3). since most gpcrs are coupled with one single subtype of g - proteins, they are broadly categorized into gi / o-, gq/11-, gs-, and g12/13-coupled receptors based on their g - protein coupling preference. predicting the coupling specificity of gpcrs to g - proteins is vital for further understanding the mechanism of signal transduction and the function of the receptors within a cell, which may provide new clues for pharmaceutical research and development. many computational methods such as the pattern discovery - based method (4), the naive bayes model (5), the chemometric approach (6), and the hidden markov model (hmm) 7., 8., 9., have been developed. furthermore, since previous experimental researches have demonstrated that the coupling specificity of gpcrs to g - proteins is mainly determined by the intracellular domains of the receptor 10., 11., the reported computational methods only used the intracellular regions of gpcr sequences as the information for the development of the prediction models. in this study, we hypothesize that, besides the intracellular regions of gpcrs, other factors such as the physiochemical properties of amino acid residues, the extracellular and transmembrane regions of gpcrs, might also have some influence on the coupling specificity, and therefore can be used as additional information to further improve the prediction accuracy. accordingly, the features of amino acid compositions and the physiochemical properties of the full - length gpcr sequences have been analyzed and extracted, and classifiers have been developed to predict the coupling specificity based on these features and support vector machines (svms). in this study, 124 human gpcr sequences (62, 33, and 29 sequences for gi / o-, gq/11-, gs - class, respectively) were collected from the gpdb database (12), which were used to develop the svm classifiers for three classes of gpcrs. ten - fold cross - validation process was used to evaluate the performance of the proposed method, that is, nine tenths of the sequences were used as the training set to extract classification features and train svm classifiers, and one tenth were used as the test set to verify the prediction results. the training and test sets were segregated at random and the process was repeated 30 times. three measures, sensitivity (sn), specificity (sp), and overall performance accuracy (acc), were used to evaluate the prediction performance. sn and sp are defined as sn = tp/(tp+fn) and sp = tn/(tn+fp), respectively, where tp is the number of correctly predicted positive samples for a specific class of gpcrs, fn is the number of incorrectly predicted positive samples, and fp is the number of incorrectly predicted negative samples. the overall performance accuracy, which measures the average accuracy of predicting the three classes of gpcrs, is defined as the percentage of all correctly predicted number of positive samples to the total number of positive samples. during the development of svm classifiers, different kernel functions were tried, and it was found that using the linear kernel function could get the best results. besides the commonly used feature of amino acid compositions, additional features such as hydrophobicity, normalized van der waals volume, polarity, polarizability, and the charge of amino acids were also used in this study for better prediction results. for each of these additional features, it is defined as the feature frequency in the form of k - mers (see materials and methods) and the value of parameter k (k 1) has a great influence on the prediction results. the results of predicting the coupling specificity for the three classes of gpcrs with different k (k = 1, 2, and 3) are given in table 1, which were obtained by using the linear kernel function and the features extracted from the full - length gpcr sequences. it can be seen that, when k = 2, the overall performance accuracy is higher than others, while the sn and sp for all three classes also achieve a relatively high level. in order to compare the prediction performance based on the information of the full - length sequences of gpcrs with that only based on the intracellular part as adopted by other researches, we predicted the transmembrane helices of these gpcrs with the programs conpred ii (13) and hmmtop 2.0 (14), then extracted the intracellular sequences and converted them into fixed - length feature vectors with the same method. the prediction results with k = 2 and k = 3 are given in table 2. the primary aim of this study is to improve the accuracy of predicting the coupling specificity of gpcrs to g - proteins by such measures as making use of the information of full - length gpcr sequences, integrating the compositional features and physiochemical properties of amino acids, and using the svm method. by comparing table 1 with table 2, it is distinct that the prediction accuracy based on the full - length sequences of gpcrs is better than that only based on the intracellular part, meaning that the full - length sequences do contain more information about the coupling specificity of gpcrs to g - proteins than the intracellular sequences. in addition, the methods based on the intracellular sequences need to extract them from the full - length sequences of gpcrs using transmembrance topology prediction programs, which may bring some errors as the accuracy of predicting the seven transmembrance -helices of gpcrs is currently only about 80%. on the contrary, this problem does not exist in the proposed method that uses the information of full - length gpcr sequences directly. furthermore, the additional features used in this study, including hydrophobicity, normalized van der waals volume, polarity, polarizability, and the charge of amino acids, can contribute to better prediction accuracy (data not shown), implying that the physiochemical properties of amino acids might also play important roles in determining the coupling specificity of gpcrs to g - proteins. it is worth noticing that the overall prediction accuracy of our method is still affected by the following factors. firstly, the size of dataset and the imbalance among different gpcr classes have a great influence on the prediction accuracy. secondly, although the collected dataset has been filtrated to only include single coupled gpcrs, it may still contain some potential promiscuous receptors, which could couple to more than one class of g - proteins and have not been validated by biological experiments. on one hand, if the training set contains the promiscuous receptors, it will influence the feature extraction of the single coupled receptors, therefore, the test set can not be classified effectively. on the other hand, if the test set has promiscuous ones, it will not obtain the overall prediction results of their coupling specificity to g - proteins. fortunately, with the accumulation of more experimental data, the influence of the above factors on the prediction accuracy will decrease gradually. in a word, the testing results demonstrate that the method proposed in this study could obtain better prediction accuracy. future work of this study will focus on exploring and integrating more features of gpcrs to further improve the accuracy of predicting the coupling specificity of gpcrs to g - proteins and to develop novel approaches to distinguish single coupled receptors from promiscuous ones. a set of human gpcr sequences with known coupling specificity was collected from the gpdb database (http://bioinformatics.biol.uoa.gr/gpdb). this database, which is useful for the study of gpcr / g - protein interactions, contains 469 species of g - proteins and gpcr sequences. we selected 124 human gpcrs that meet the following criteria : firstly, only single coupled receptors (only couple to one class of g - proteins) were included in the dataset. g12/13-coupled receptors were not included because of insufficient data. secondly, those gpcr sequences labeled with finally, the gpcrs were divided into three groups according to their coupling specificity, and the gi / o-, gq/11-, and gs - coupled receptors contained 62, 33, and 29 sequences, respectively. furthermore, all of these sequences were verified with the tips (15) and swiss - prot database. generally, in the process of constructing the positive and negative samples for developing classifiers, two kinds of methods are wildly used, one is the one - against - other (1-v - n) method, and the other is the one - against - one (1-v-1) method. supposing there are n classes to be classified, the one - against - other method means to pick up the samples in one class as positive and the ones in remnant classes as negative. another method, one - against - one, uses the samples in one class as positive and the ones in another class as negative. in this study, the numbers of gpcr sequences for the classes gq/11 and gs are not large enough, which may cause the imbalance problem in the dataset. the one - against - other method will further aggravate the imbalance problem, while the one - against - one method can improve the prediction accuracy for classes with fewer samples, and therefore was adopted in this study. for each gpcr sequence, the feature vector was assembled from the encoded representations of amino acid compositions, hydrophobicity, normalized van der waals volume, polarity, polarizability, and charge. two different coding schemes were adopted for the amino acid compositions and the five physiochemical properties, respectively. according to the amino acid compositions, a protein sequence is represented by a vector in a 20-dimensional space : xa=[f1,f2,,f20]t where fi (i = 1, 2,, 20) is the occurrence frequency of the twenty amino acids in the sequence. for each of the five physiochemical properties, the twenty amino acids are grouped into three classes represented by pi (i = 1, 2, and 3) according to their different values. so a primal sequence is transformed into five different physiochemical sequences consisting of p1, p2, and p3, which are called pcseq. then, the k - mer vector c and the distribution vector d for the pcseq corresponding to each of the five physiochemical properties are calculated, respectively 16., 17.. given an integer k 1, k - mers are composed of all the continuous subsequences with length k. there are possibly 3 permutation and combination of the subsequences. so the k - mer vector c is a vector with 3 dimensions and the value of each dimension is the occurrence frequency of every subsequence in the pcseq. the distribution vector d, which is used to describe the global distribution of the property in the pcseq, is described by five chain lengths (in percent), within which 25%, 50%, 75%, and 100% of the amino acids with a certain class pi in each of the five properties are contained. it is defined as:(2)d=i=13j=14pos(l(i)j25%)l(seq)100% where l(i) is the number of amino acids in the special class pi, and l(seq) is the length of pcseq. for each of the chosen physiochemical properties, its k - mer vector c and the distribution vector d were calculated and combined. finally, a protein sequence was converted into a vector with [20 + (3 + 4 3) 5) ] dimensions as the input of the svm classifiers. svm is a standard supervised learning algorithm based on recent developments in the statistical learning theory 18., 19.. it builds a hyperplane separating the positive and negative examples in multiple - dimensional space. the svm calculation was implemented by using the libsvm 2.8 (20) software package. the software enables the user to choose different parameters and kernel functions including linear kernel function, radial basis function, and polynomial kernel function to obtain the best effect. in this study, three svms were constructed for classifying the gi / o-, gq/11-, and gs - gpcrs. the comparison results of using different kernel functions show that the linear kernel function can achieve the best accuracy, which is therefore used in the developed svm classifiers. in addition, the penalty factor c is an important parameter of svm, which has a great influence on the prediction results. in this study, the optimal value of this parameter was searched in the range of 1 to 200 by comparing the prediction results. a set of human gpcr sequences with known coupling specificity was collected from the gpdb database (http://bioinformatics.biol.uoa.gr/gpdb). this database, which is useful for the study of gpcr / g - protein interactions, contains 469 species of g - proteins and gpcr sequences. we selected 124 human gpcrs that meet the following criteria : firstly, only single coupled receptors (only couple to one class of g - proteins) were included in the dataset. g12/13-coupled receptors were not included because of insufficient data. secondly, those gpcr sequences labeled with finally, the gpcrs were divided into three groups according to their coupling specificity, and the gi / o-, gq/11-, and gs - coupled receptors contained 62, 33, and 29 sequences, respectively. furthermore, all of these sequences were verified with the tips (15) and swiss - prot database. generally, in the process of constructing the positive and negative samples for developing classifiers, two kinds of methods are wildly used, one is the one - against - other (1-v - n) method, and the other is the one - against - one (1-v-1) method. supposing there are n classes to be classified, the one - against - other method means to pick up the samples in one class as positive and the ones in remnant classes as negative. another method, one - against - one, uses the samples in one class as positive and the ones in another class as negative. in this study, the numbers of gpcr sequences for the classes gq/11 and gs are not large enough, which may cause the imbalance problem in the dataset. the one - against - other method will further aggravate the imbalance problem, while the one - against - one method can improve the prediction accuracy for classes with fewer samples, and therefore was adopted in this study. for each gpcr sequence, the feature vector was assembled from the encoded representations of amino acid compositions, hydrophobicity, normalized van der waals volume, polarity, polarizability, and charge. two different coding schemes were adopted for the amino acid compositions and the five physiochemical properties, respectively. according to the amino acid compositions, a protein sequence is represented by a vector in a 20-dimensional space : xa=[f1,f2,,f20]t where fi (i = 1, 2,, 20) is the occurrence frequency of the twenty amino acids in the sequence. for each of the five physiochemical properties, the twenty amino acids are grouped into three classes represented by pi (i = 1, 2, and 3) according to their different values. so a primal sequence is transformed into five different physiochemical sequences consisting of p1, p2, and p3, which are called pcseq. then, the k - mer vector c and the distribution vector d for the pcseq corresponding to each of the five physiochemical properties are calculated, respectively 16., 17.. given an integer k 1, k - mers are composed of all the continuous subsequences with length k. there are possibly 3 permutation and combination of the subsequences. so the k - mer vector c is a vector with 3 dimensions and the value of each dimension is the occurrence frequency of every subsequence in the pcseq. the distribution vector d, which is used to describe the global distribution of the property in the pcseq, is described by five chain lengths (in percent), within which 25%, 50%, 75%, and 100% of the amino acids with a certain class pi in each of the five properties are contained. it is defined as:(2)d=i=13j=14pos(l(i)j25%)l(seq)100% where l(i) is the number of amino acids in the special class pi, and l(seq) is the length of pcseq. for each of the chosen physiochemical properties, its k - mer vector c and the distribution vector d were calculated and combined. finally, a protein sequence was converted into a vector with [20 + (3 + 4 3) 5) ] dimensions as the input of the svm classifiers. svm is a standard supervised learning algorithm based on recent developments in the statistical learning theory 18., 19.. it builds a hyperplane separating the positive and negative examples in multiple - dimensional space. the svm calculation was implemented by using the libsvm 2.8 (20) software package. the software enables the user to choose different parameters and kernel functions including linear kernel function, radial basis function, and polynomial kernel function to obtain the best effect. in this study, three svms were constructed for classifying the gi / o-, gq/11-, and gs - gpcrs. the comparison results of using different kernel functions show that the linear kernel function can achieve the best accuracy, which is therefore used in the developed svm classifiers. in addition, the penalty factor c is an important parameter of svm, which has a great influence on the prediction results. in this study, the optimal value of this parameter was searched in the range of 1 to 200 by comparing the prediction results. | g - protein coupled receptors (gpcrs) represent one of the most important classes of drug targets for pharmaceutical industry and play important roles in cellular signal transduction. predicting the coupling specificity of gpcrs to g - proteins is vital for further understanding the mechanism of signal transduction and the function of the receptors within a cell, which can provide new clues for pharmaceutical research and development. in this study, the features of amino acid compositions and physiochemical properties of the full - length gpcr sequences have been analyzed and extracted. based on these features, classifiers have been developed to predict the coupling specificity of gpcrs to g - proteins using support vector machines. the testing results show that this method could obtain better prediction accuracy. |
neuroblastoma, the most common extracranial solid pediatric malignancy, is an embryonal tumor of the sympathetic nervous system. along with rhabdomyosarcoma, ewing sarcoma and lymphoma, these malignancies collectively represent the small, round blue cell tumors of childhood. in the united states the incidence is estimated at 1 in 10,000 births or about 500 new cases per year. neuroblastoma has been described as an enigmatic tumor because of its highly variable biologic behavior. tumors may spontaneously regress, differentiate into benign ganglioneuromas or follow an unrelenting progressive course with ultimate fatal outcome. more than 50% of patients present with high - risk features including large, unresectable tumors and widely metastatic disease. the prognosis for these patients remains suboptimal with a long - term survival of about 40%. the international neuroblastoma staging system (inss), developed in 1988 and modified in 1993, is still used by many cooperative groups today. this system relies on tumor resectability as well as pathologic features of the tumor (table 1). a limitation of the system is that the same tumor can be classified as inss stage 1 or 3 depending on the local surgeon 's experience and expertise. also, tumors that are expected to spontaneously regress can not be adequately staged using the inss. in addition, assessment of lymph node involvement is difficult to apply uniformly across institutions. these drawbacks led to heightened international collaboration to facilitate comparison of results of clinical trials performed worldwide. in 2004 the international neuroblastoma risk group (inrg) task force was formed to develop the inrg staging system (inrgss) and inrg risk classification system, both published in 2009. table 1the original international neuroblastoma staging systemtumor stagedescription1localized tumor with complete gross excision, with or without microscopic residual ; representative ipsilateral lymph nodes negative for tumor. nodes attached to and removed with tumor may be positive2alocalized tumor with incomplete gross excision ; ipsilateral nonadherent lymph nodes negative for tumor2blocalized tumor with or without complete gross excision, ipsilateral nonadherent lymph nodes positive for tumor ; enlarged contralateral lymph nodes negative for tumor3unresectable unilateral tumor infiltrating across midline (beyond opposite side of vertebral column) with or without regional lymph node involvement, or midline tumor with bilateral extension via infiltration (unresectable) or lymph node involvement4any primary tumor with dissemination to distant lymph nodes, bone, bone marrow, liver, skin, and/or other organs (except as defined for stage 4s)4slocalized primary tumor with disseminated disease limited to skin, liver and/or bone marrow (only in infants < 1 year, marrow involvement < 10% on biopsy and mibg negative marrow) the original international neuroblastoma staging system the inrgss is designed to stage patients before surgery or other therapy. tumors are classified as l1 or l2 disease based on whether one or more of 20 imaging - defined risk factors (idrf) are present. the idrfs are imaging features that predict the risk of tumor resection. with the inrgss since imaging can be retrospectively and centrally reviewed by experts in the field, a system based on baseline imaging features should be more robust and reproducible than one based on surgical resection. it is hoped that this will result in an accelerated refinement of risk stratification and more appropriate therapies for individual patients. the inrgss is not intended to replace the inss but should be used in parallel. because inrgss staging is based on imaging features, the radiologist 's role will be increased. the purpose of this review is to heighten the radiologist 's awareness of the definitions and importance of the idrfs in neuroblastoma. there are four inrgss stages : (1) stage l1 tumors are localized tumors that do not involve vital structures as defined by the idrfs (table 2). tumor must be confined to one body cavity, i.e. neck, chest, abdomen or pelvis. the isolated finding of intraspinal tumor extension does not fulfill the criteria for an irdf and such tumors are considered stage l1. for example, a left - sided abdominal tumor with left - sided chest involvement is considered l2. however, a left - sided abdominal tumor with clearly right - sided chest involvement is considered metastatic. (3) stage m is defined as distant metastatic disease (not contiguous with the primary tumor) except when defined as stage ms. non - regional, distant, lymph node involvement is considered metastatic disease. however, an upper abdominal tumor with enlarged lower mediastinal nodes or a pelvic tumor with inguinal adenopathy is considered local regional disease. ascites and pleural effusion, even when they contain malignant cells, do not constitute metastatic disease unless they are remote from the body compartment of the primary tumor. (4) stage ms is metastatic disease in patients younger than 18 months (547 days) with metastases confined to the skin, liver and/or bone marrow. bone marrow involvement must be limited to < 10% of total nucleated cells on smears or biopsy. if the primary tumor shows avidity for [i]meta - iodobenzylguanine (mibg) there must be no evidence of bone or bone marrow disease on mibg nuclear scintigraphy. if the primary tumor is not mibg avid, there must be no evidence of bone or bone marrow involvement on [tc]methyldiphosphonate (mdp) nuclear bone scan. the primary tumor can be l1 or l2 and there is no restriction regarding crossing the midline. in addition to the irdfs and independent of stage, three special conditions should be recorded : (1) multifocal primary tumors, (2) pleural effusion, and (3) ascites. patients with multifocal tumors should be staged according to the greatest extent of disease as defined above. table 2description of imaging - defined risk factors for the international neuroblastoma risk group staging systemanatomic regiondescriptionmultiple body compartmentsipsilateral tumor extension within two body compartmentsnecktumor encasing carotid artery, vertebral artery, or jugular veintumor extending to skull basetumor compressing tracheacervicothoracic junctiontumor encasing brachial plexustumor encasing subclavian vessels, vertebral artery or carotid arterytumor compressing tracheathoraxtumor encasing aorta or major branchestumor compressing trachea or main bronchilower mediastinal tumor infiltrating costovertebral junction between t9 and t12 vertebral levelsthoracoabdominal junctiontumor encasing aorta or vena cavaabdomen and pelvistumor infiltrating porta hepatis or hepatoduodenal ligamenttumor encasing branches of superior mesenteric artery at mesenteric roottumor encasing origin of celiac axis or superior mesenteric arterytumor invading one or both renal pediclestumor encasing aorta or vena cavatumor encasing iliac vesselspelvic tumor crossing sciatic notchintraspinal tumor extensionintraspinal tumor extension (any level) provided that more than one - third of spinal canal in axial plane is invaded, the perimedullary leptomeningeal spaces are not visible, or the spinal cord intensity is abnormalinfiltration of adjacent organs and structurespericardium, diaphragm, kidney, liver, duodenopancreatic block, and mesentery description of imaging - defined risk factors for the international neuroblastoma risk group staging system to promote reproducible staging it is recommended that radiologists use specific terms to describe the relationship between tumors and neighboring vital structures. separation means that a visible layer (usually fat) is present between the tumor and the neighboring structure. when a tumor is separated from a vital structure an irdf is not present.contact means no visible layer is present between the tumor and adjacent structure. for an artery, the term flattened is used to describe veins with reduced diameter that still have a partially visible lumen. when a tumor is in contact with a vital structure or is flattening a vein without encasement, an idrf is not present, except in the case of renal vessels (see below).encasement means that the neighboring structure is surrounded by tumor. a flattened vein with no visible lumen is considered to be encased.compression is used only when referring to airways. when tumor contacts an airway and causes the short axis to be reduced, this is considered an idrf. for other vital structures, a contact may cause displacement (abnormal anatomic location) or distortion (abnormal anatomic shape), but these situations are not considered idrfs unless there is infiltration or total encasement.infiltration refers to involvement of vital structures other than vessels since infiltration of a vessel wall can not be determined from imaging. an infiltrating tumor demonstrates extension into an adjacent organ thus causing the margins between them to be absent or poorly defined. when a tumor infiltrates an adjacent structure an idrf is present.because surgical dissection of the renal pedicle is risky in patients with neuroblastoma, an idrf is present even if the strict criteria for encasement are not fulfilled, that is, even if the tumor is only in contact with the renal vessels. separation means that a visible layer (usually fat) is present between the tumor and the neighboring structure. contact means no visible layer is present between the tumor and adjacent structure. for an artery, the term flattened is used to describe veins with reduced diameter that still have a partially visible lumen. when a tumor is in contact with a vital structure or is flattening a vein without encasement, an idrf is not present, except in the case of renal vessels (see below). when tumor encases a vital structure, an idrf is present. for a vessel, total encasement means that a vital structure is completely surrounded by tumor. a flattened vein with no visible lumen is considered to be encased. compression is used only when referring to airways. when tumor contacts an airway and causes the short axis to be reduced, this is considered an idrf. for other vital structures, a contact may cause displacement (abnormal anatomic location) or distortion (abnormal anatomic shape), but these situations are not considered idrfs unless there is infiltration or total encasement. infiltration refers to involvement of vital structures other than vessels since infiltration of a vessel wall can not be determined from imaging. an infiltrating tumor demonstrates extension into an adjacent organ thus causing the margins between them to be absent or poorly defined. when a tumor infiltrates an adjacent structure an idrf is present. because surgical dissection of the renal pedicle is risky in patients with neuroblastoma, an idrf is present even if the strict criteria for encasement are not fulfilled, that is, even if the tumor is only in contact with the renal vessels. an idrf is present when more than one - third of the spinal canal, in the axial plane, is infiltrated, the leptomeningeal fluid spaces are no longer visible or the spinal cord magnetic resonance signal intensity is abnormal. tumors that infiltrate the spinal canal below the level of the spinal cord are considered idrfs if they fulfill these criteria. a lower mediastinal tumor that infiltrates the costovertebral junction between the t9 and t12 vertebral levels is associated with a theoretic risk of spinal cord ischemia caused by surgical injury to the anterior spinal artery (artery of adamkiewicz) and is considered an idrf. because injury to the inferior mesenteric artery (i m a) almost never causes complications, encasement of this vessel is not considered an idrf (i.e. the i m a is not a vital structure). kidneys can be infiltrated through the cortex, by adrenal tumors, or through the renal hilum by retroperitoneal tumors. approximately 50% of neuroblastoma patients present with metastatic disease. in the inrgss, metastatic disease is designated stage m and is distinct from stage ms which refers to metastatic disease in children younger than 18 months with metastases confined to the skin, liver, and/or bone marrow (< 10% involvement on bone marrow biopsy with negative mibg). patients with lymph node involvement outside the body cavity of the primary tumor are considered to have disseminated metastatic disease. metastases occur hematogenously, most commonly to the bone marrow (70%) or bone (55%) and less commonly to the liver. metastatic disease to the lung and brain parenchyma is seen in end - stage disease and is becoming more commonly recognized in children undergoing current therapy who have longer survival. distant metastasis must be assessed with mibg nuclear scintigraphy. because approximately 10% of neuroblastoma is non - mibg avid, patients with non - mibg avid primary tumors should be assessed with [tc]mdp bone scan. one unequivocal site of abnormal, distant mibg avidity is sufficient to define metastatic disease. however, a solitary, equivocal focus of mibg uptake must be confirmed with additional imaging or biopsy. the use of single - photon emission computed tomography (spect)-ct has proven utility in accurately localizing sites of mibg avidity when planar mibg imaging or diagnostic ct or mr imaging is equivocal. to standardize the assessment of extent of bone / bone marrow disease and response to therapy, a semi - quantitative scoring system as efforts are made by the international community toward standardizing the staging of children with neuroblastoma the role of the radiologist is increasing. therefore, it is important for radiologists to be familiar with the idrfs set forth by the inrg. because the inrgss is based on the extent of disease before surgery or other therapy, the criteria should be more robust and reproducible than the prior staging system, which was based on extent of surgical resection. the goal of the inrgss is to facilitate the comparison of clinical trials worldwide and ultimately accelerate the advancement of treatment strategies for children with neuroblastoma. | abstractneuroblastoma is the most common extracranial solid malignancy in children. the tumor has variable biological behavior that can be predicted by patient age, genetic features, tumor biology and extent of disease at diagnosis. factors chosen by various cooperative groups to define risk of treatment failure have been non - uniform. therefore, historically, it has been difficult to compare outcomes across clinical trials performed around the world. this has hindered the advancement of treatment strategies to improve survival of these patients. the international neuroblastoma risk group (inrg) was established in 2004 to develop a consensus approach to pretreatment risk stratification. the result was the development of the inrg staging system (inrgss) which relies on imaging - defined risk factors (idrfs) that are determined before surgery or other therapy. with the application of the inrgss the radiologist 's role in staging children with neuroblastoma is increased. this review provides an overview of the inrgss and the idrfs. |
research into the synthesis of noble metal nanoparticles is motivated by the opportunity to harness advantages not present in their bulk equivalents, such as high surface atom to volume ratios, semiconductor properties, and, in some cases, magnetic properties. however, nanosized ir particles have received limited attention from the scientific community compared to that of other noble metal counterparts. synthetic methods involving highly specified equipment, extreme reaction conditions, and/or specialty chemicals have been the primary culprits of this conundrum. in our recent studies, we reported the successful synthesis of dodecanethiolate - capped pd nanoparticles generated from sodium s - dodecylthiosulfate after the cleavage of the sulfite group. the overall lower reactivity of this ligand precursor compared to alkanethiol allowed the successful synthesis of pd nanoparticles without the formation of oxidized pd(ii) species during and after the reaction. further studies from our group using the thiosulfate synthetic method led to the discovery of a way to control ligand surface coverage that has a direct correlation with catalytic activity and selectivity of alkanethiolate - capped pd nanoparticles. many studies have previously revealed that the indistinguishable metal sulfur bonds result from the adsorption of thiosulfate precursors and from the direct adsorption of thiols on metal nanoparticles and flat metal surfaces. for ir nanoparticles, however, such stable alkanethiolate - capped nanoparticles were unattainable by employing alkanethiols directly as a ligand and nabh4 as a reducing agent thus far. in this article, we relate a facile synthesis of 1.2 0.3 nm ir nanoparticles by employing the modified brust schiffrin system along with the aforementioned thiosulfate ligand precursor strategy. new insights into the mechanistic disparities between sodium s - alkanethiosulfate and alkanethiol are obtained by investigating the formation chemistry of alkanethiolate - stabilized ir nanoparticles using these two organic ligand precursors. the following reagents were obtained from the indicated suppliers and used as received : tetra - n - octylammonium bromide (98%), 1-dodecanethiol (98%), and sodium borohydride (98%) were obtained from acros. sodium thiosulfate pentahydrate (na2s2o35h2o) along with solvents such as toluene, acetone, ethanol, and methanol was purchased from fisher scientific. water was purified by using a barnstead nanopure diamond ion exchange resins purification unit. tetra - n - octylammonium bromide (2.0 mmol) was dissolved in 25 ml of toluene. precisely measured k2ircl6 (0.40 mmol) dissolved in 25 ml of water was added to the organic solution. the mixture was continuously stirred until the aqueous layer was cleared signifying the completion of the phase transfer. the organic layer was separated and placed in a 250 ml round - bottomed flask. sodium s - dodecylthiosulfate (0.80 mmol) along with another portion of tetra - n - octylammonium bromide (2.0 mmol) was added to the round - bottomed flask with the aid of 10 ml of aq methanol (40% v / v). the reaction mixture was placed in 60 c water bath and stirred for 15 min. subsequently, 8.0 ml of a freshly prepared solution of sodium borohydride (1 m) was rapidly poured into the reaction mixture. within 4 min, the color of the reaction changed from red to yellow to brown to finally black indicating the formation of nanoparticles. after stirring for 1 h, the nanoparticle mixture was removed from the water bath. upon cooling to room temperature, the organic layer was washed with several aliquots of nanopure water and isolated using a separatory funnel. lastly, the nanoparticle crude was extensively washed with ethanol, methanol, and acetone on a course frit funnel (f). iridium nanoparticles were ultimately recollected by reconstitution with chloroform, in which the solution was vacuum - dried to obtain solid powders. h nmr spectra were recorded using bruker ac400 ft - nmr operating at 400 mhz. infrared spectra were acquired by attenuated total reflectance (atr) using a perkinelmer spectrum 100 ft - ir spectrometer. transmission electron microscope (tem) images were obtained with a jeol 1200 ex ii electron microscope operating at 90 kev. samples were prepared by placing 25 l of an ir nanoparticle toluene solution (1 mg / ml) on a 200 mesh copper grid with formvar film. size distribution analysis of ir nanoparticle core microscope images was executed with scion image beta release 2tm. thermogravimetric analysis (tga) was conducted using ta instruments sdt q600 with a flow rate of 100 ml / min of n2 with heating from room temperature to 600 c. xps measurements were performed using a mg k source (xr50, specs gmbh) and a hemispherical electron energy analyzer (phoibos 100, specs gmbh). spectra were acquired with 10 ev pass energy and normalized to the o1s binding energy at 528.5 ev. similar to the studies by lennox., the mechanistic aspects of the nanoparticle synthesis were evaluated by comparing h nmr and uv vis spectra of the reaction precursors, intermediates, and final products formed by the direct application of either 1-dodecanethiol or sodium s - dodecylthiosulfate as a ligand precursor (scheme 1). since the size, composition, and physical properties of the nanoparticles synthesized by the modified brust schiffrin reactions are highly dependent upon the specific reaction conditions, additional mechanistic insights into this procedure regarding different types of capping ligands and atypical metals may allow further expansion of available nanomaterials toward nanoparticles with exotic characteristics. at the onset of this synthesis, aqueous ircl6 was transferred to toluene - d8 by employing a large excess of tetra - n - octylammonium bromide as a phase transfer agent. this transfer took place just as observed for gold nanoparticles accompanying the colorimetric change of both aqueous and organic phases (figure 1 : from a to b). the [r4n]2[irx6 ] complex in organic phase, however, failed to form a homogeneous solution at room temperature and could only be fully mixed after continuous stirring at a higher temperature of 60 c. vis spectra of irx6 in the organic phase showed two strong absorption bands at 440 and 500 nm, which correspond to the presence of ir - x (either cl or br) bonds, with a weak absorption band at 595 nm (figure s1, supporting information). these absorption bands for ir - x appeared at a slightly higher wavelength, compared to that of the same bands observed for ircl6 in water before the phase transfer, but were without any significant change in their intensity. the h nmr spectra of [r4n]2[irx6 ] in toluene - d8 revealed the ch2-n peaks at 2.65 ppm, which have been dramatically shifted to more upfield from their original chemical shift of 3.40 ppm (figure 2a). have reported similar dramatic shifts of ch2-n peaks of the tetra - n - octylammonium complex during the brust schiffrin reaction using haucl4 and proposed that this phenomena was due to the formation of inverse micelle structures with aucl4 complexation in their pore. have shown that the same shifts resulted from the ion - pair complex formation without the presence of an inverse micelle of tetraoctylammonium. on the basis of the latter hypothesis, our nmr data support the formation of an ion - pair complex of tetra - n - octylammonium with irx6. the interaction between the positively charged quaternary ammonium nitrogen and irx6 was the primary reason for the upfield shifts of both ch2-n peaks and ch2-ch2-n peaks of tetra - n - octylammonium salts. picture of solutions containing (a) k2ircl6(aq) (0.4 mmol), (b) [r4n]2[ircl6](toluene), (c) 1-dodecanthiol (0.8 mmol) added to b, (d) nabh4 (4.0 mmol) added to c, and (e) s - dodecylthiosulfate (0.8 mmol) and nabh4 (4.0 mmol) added to b. h nmr spectra of (a) [r4n]2[irx6 ] in toluene - d8 obtained after mixing the organic (toluene - d8) layer of toab (2.0 mmol) and the aqueous (d2o) layer of k2ircl6 (0.4 mmol), (b) 1-dodecanthiol (0.8 mmol) added to a, (c) 1-dodecanthiol (1.6 mmol) added to a, (d) nabh4 (4.0 mmol) added to c, (e) s - dodecylthiosulfate (0.8 mmol) added to a, and (f) ir nanoparticle in cdcl3 after purification. the multiplet resonance at 2.09 ppm is due to the presence of toluene solvent impurity. the addition of 2 equiv of 1-dodecanthiol under the reaction temperature of 60 c resulted in color change from dark brown to bright yellow as demonstrated in figure 1c and the reaction progression in figure s2 (supporting information). the color change indicates the probable reduction of ir to ir, which has also been observed from the reduction of ircl6 (dark brown) to ircl6 (brownish yellow). previously, zhu. were able to confirm the complete reduction of au to au by the addition of 2 equiv of alkanethiols, which were oxidized to disulfides, during the brust schiffrin synthesis of ir nanoparticles using 1-dodecanethiol, which subsequently showed small peaks representative of dodecyldisulfide (2.54 ppm) and 1-dodecanethiolate (2.18 ppm), along with the ch2-n peaks of tetra - n - octylammonium downshifted back to their original chemical shift of 3.40 ppm. this change in nmr spectra implies that the reduced ir complex is no longer directly associated with tetra - n - octylammonium salts, which now exclusively form the ion - pair complex with halide ions (figure 2b). clear evidence of the reaction between irx6 with 1-dodecanethiol was shown in figure s3 (supporting information), which illustrates the uv vis spectra of the reaction mixture after the addition of 4 equivs of 1-dodecanethiol. the spectra showed complete disappearances of the strong absorption bands at 440 and 500 nm, indicating the cleavage of ir - x (either cl or br) bonds. the appearance of absorption bands at 310 nm is most likely due to the formation of ir - sr bonds. the h nmr spectra of the reaction mixture after the addition of 4 equivs of dodecanethiol shown in figure 2c also support the formation of dodecyldisulfide from 1-dodecanethiol after the reaction with irx6. the relative intensity of these peaks at 2.54 ppm and 2.18 ppm was 1 to 3 in favor of dodecanethiolate, confirming the formation of the ir(sr)3 complex. one equiv of 1-dodecanthiol was, therefore, used for the reduction of ir to ir, and the other 3 equivs of thiol participated in the complexation with ir. the direct evidence of ir - sr bond formation could be obtained from a closer analysis of h nmr spectra. the peaks at 2.18 ppm exhibited a multiplicity (triplet of triplet) rather than a triplet typically observed from ch2ch2-s or a quartet observed from ch2ch2-sh. spin coupling of ir h (j) and h h (j) for the ir(sr)3 complex. to our knowledge, however, such an interaction of three bond (ir s - c - h) ir h coupling has never been reported. interestingly, the h nmr studies of ir h complexes have only shown the tendency for ir to self - decouple for j coupling. considering the spin number (i = 3/2) of ir, the coupling of ir h (j) should produce a quartet splitting instead of a triplet splitting as shown in figure 2c, inset. despite this inconclusive nmr splitting, the presence of this abnormal multiplicity strongly supports the presence of an ir h (j) interaction and thus the formation of the ir s bond. the addition of nabh4, a highly basic reducing agent, was enacted in order to produce ir nanoparticles from an ir(sr)3 complex. upon the addition of nabh4, the color of the solution turned into strong orange as shown in figure 1d. this color change was followed by the formation of insoluble gel - like materials during further stirring of the reaction mixture (figure s4, supporting information). moreover, uv vis spectra of the reaction mixture did not resemble that of a typical nanoparticle solution but instead showed strong absorption bands centered at 330 nm. this result indicated the probable formation of the hydrolysis product rather than the desired reduction of ir to ir after the addition of basic nabh4 solution. insoluble ir(oh)6(na)y would precipitate out in toluene as shown in figure s4 (supporting information), and more soluble ir(oh)6(r4n)y would result in the appearance of strong absorption bands at 330 nm. the uv data also suggested the reaction did not involve the reformation of irx6 or the formation of iroxnh2o, which have strong absorption bands at 440/500 nm and 580 nm, respectively. the nmr spectra of the reaction mixture after the addition of nabh4 shown in figure 2d indicated the full conversion of the dodecanethiolate ligand of the ir(sr)3 complex to its disulfide form in the presence of basic sodium borohydride solution. in contrast to the alkanethiol, the addition of s - dodecylthiosulfate to the reaction mixture containing the [r4n]2[irx6 ] adduct did not trigger any change in the solution color and absorption bands of ir - x at 440 and 500 nm in uv vis spectra. the h nmr spectra of [r4n]2[irx6 ] in toluene - d8 were also nearly unaffected by the addition of s - dodecylthiosulfate, which showed ch2-s peaks at 3.28 ppm (figure 2e). a slight upfield shift from 2.65 ppm to 2.48 ppm was observed for the ch2-n peaks. since the structure of s - dodecylthiosulfate is highly reminiscent of hydrophobic ionic salts, the formation of an ion - pair complex of [r4n][rs2o3 ] and the rapid equilibrium with [r4n]2[irx6 ] would cause such a change in the chemical shifts. the overall spectroscopic results clearly demonstrated the low reactivity of the thiosulfate ligand precursors compared to thiols against the iridium complex. the addition of nabh4 to the reaction mixture containing [r4n]2[irx6 ] and s - dodecylthiosulfate initially turned the solution color from dark brown to faint yellow implying the cleavage of the ir - x bond, but the solution turned into dark black / blown within 5 min of nabh4 addition (figure s5, supporting information). this result suggested that the formation of ir nanoparticles is slower than that of other nanoparticles including au, ag, and pd, which undergo color changes into black / blown immediately upon the addition of nabh4. vis spectra of the isolated ir nanoparticles showed an exponential decay in absorbance with a decrease in energy, which is a typical characteristic of small nanosized colloids lacking surface plasmon resonance as is the case with ir (figure s6, supporting information). the h nmr of the ir nanoparticles isolated and redissolved in cdcl3 revealed three broad resonances at 1.801.60, 1.501.20, and 0.900.80 ppm for the -ch2-ch2-s, -ch2-, and -ch3, respectively (figure 2f). these peaks resulted from the attached dodecanethiolate stabilizers on the nanoparticle surface, as peak broadening has been indicative of ligand immobilization for other ligand - capped metal nanoparticles. interestingly enough, the small core size of these nanoparticles allow the -protons of attached organic ligand stabilizers to be visible ; a rare event only observed for the small and monodisperse metal nanoparticles. moreover, the high purity of the isolated ir nanoparticles was proven to be attributed to the absence of resonances at 3.40 (tetra - n - octylammonium : ch2-n), 3.28 ppm (s - dodecylthiosulfate : ch2-n), 2.54 (didodecyl disulfide : ch2-s), and 2.18 (dodecanethiolate : ch2-s). ft - ir spectra of ir nanoparticles were also identical to those of metal nanoparticles previously generated from both dodecanethiol and s - dodecylthiosulfate (figure s7, supporting information). only the ch2 and ch3 stretches (30002800 cm) and bendings (1450 cm) of dodecanethiolate monolayers were observed in the spectra. any other significant peaks including sulfonate (so3) stretches at 1350 (ass = o ; strong) and 1175 cm (ss = o ; strong) were not observed implying the cleavage of the thiosulfate s s bond after the adsorption of thiosulfate on the ir nanoparticle surface. the tem image and the core size histogram of the final purified product are presented in figure 3. the average core size of the ir nanoparticles was determined to be 1.2 0.3 nm by counting a total of 2300 particles from multiple images. the small size and high monodispersity of these nanoparticles are quite novel for ir nanostructures because such cluster - like, stable, and isolable ir nanoparticles have never been reported previously. the overall organic and metallic weight fractions could be determined by thermogravimetric analysis (figure s8, supporting information). the initial major volatilization of these iridium nanoparticles took place close to 150 c, which is quite similar to that in our prior studies involving palladium nanoparticles. after the final temperature of 600 c was reached, 61.5% of the residual sample was still present signifying an organic fraction of 38.5% for these ir nanoparticles. xps spectra of the ir4f7 (60.8 ev) and ir4f5 (63.8 ev) region for ir nanoparticles are shown in figure 4a. the broad xps s2p signal at 162.2 ev (figure 4b) revealed the presence of an ir small traces of oxidized s, which are clearly differentiated from the high intense peaks observed for oxidized s species of the thiosulfate ligand precursor (figure 4c), were observed at 1668 ev. since the absence of unbound thiosulfate was confirmed by nmr and ir, the small amount of oxidized s species observed in xps spectra was most likely due to the small presence of chemisorbed oxidized sulfur species such as sulfur trioxide or sulfite that were cleaved off from thiosulfate precursors. this result demonstrated that the removal of surface adsorbed oxidized sulfur species is somewhat incomplete for ir nanoparticles. (a) ir4f xps spectra and (b) s2p xps spectra of dodecanethiolate - capped iridium nanoparticles (c = 2 mg ml). ultimately, one of the main reasons this reaction produces stable and isolable ir nanoparticles was that all necessary reagents (the ir complex, ligands, and reducing agent) for nucleation growth passivation of ir nanoparticles form ionic pair complexes with tetraoctylammonium salts and, therefore, are present at close proximity to each other. the activation energy of the reaction is likely decreased thereby aiding the completion of the nanoparticle stabilization stage. in comparison, the thiol protocol involves the nonionic ir(sr)3 complex as a key intermediate, and the hydrophobic alkyl tail parts of tetraoctylammonium might act as a kinetic barrier for the further reduction of ir to ir by ion - paired bh4. small ir clusters have been predicted to have magnetic moments larger than 0.5 b / atom. however, based on our knowledge, there has never been any published report on experimental work related to stable and unsupported ir nanoparticles with a detectible magnetic moment. the successful synthesis of small ir nanoparticles capped with dodecanethiolate ligands allowed us, for the first time, to examine the magnetic properties of the cluster - like ir particles. macroscopic magnetization measurements have been performed at temperatures ranging from 5 to 300 k using quantum design physical property measurement system. the ir nanoparticles were found to have a relatively large magnetic moment which increases with stronger external fields as shown in figure 5a. the saturation magnetization, determined using tga analysis of the nanoparticle sample, was found to be 12.2 emu / g of ir at 300 k and 13.0 emu / g of ir at 5 k. this value is higher than the saturation magnetization of dendrimer - encapsulated ni nanoparticles and other alkaenthiolate - capped metal nanoparticles. the preservation of the magnetic signal from 5 to 300 k (only a decrease of 6%) is observed. the hysteresis loop at 300 and 5 k shows the nanoparticles to have a coercitivity of 54 and 105 oe, respectively. in addition, both the zero - field - cooled (zfc) and field - cooled (fc) temperature dependence of the magnetization were measured in a 100 oe applied field (figure 5b). the maximum in the zfc curve and divergence in the zfc and fc curves indicate a blocking temperature, tb, of more than 300 k. the absence of any significant amount of magnetic impurity such as fe was confirmed from xps results. the overall characteristics of ir nanoparticles suggest that they are soft magnetic materials with ferromagnetic properties. more in - depth studies on the magnetic behavior of ir nanoparticles with different core sizes and ir / thiolate compositions will be done and reported in the near future. (a) magnetization curves of dodecanethiolate - capped iridium nanoparticles obtained at 300 and 5 k ; the inset shows the similar coercive fields at 300 and 5 k. (b) temperature dependence of the magnetization of iridium nanoparticles measured in a 100 oe applied magnetic field. the synthesis of stable and isolable iridium nanoparticles with an average core size of 1.2 nm was achieved by employing sodium s - dodecylthiosulfate as a ligand precursor. it was also demonstrated that employing dodecanethiol directly under identical conditions fails to yield iridium nanoparticles. to our knowledge, our article stands as the lone method for producing stable alkanethiolate - capped ir nanoparticles using sodium borohydride reduction. schiffrin mechanism and the reason thiosulfate ligands are preferred over thiol ligands for the synthesis of ir nanoparticles. finally, the produced ir nanoparticles exhibited strong magnetic moments demonstrating the potential of these ir nanoparticles for various technological applications. | the synthesis of stable and isolable iridium nanoparticles with an average core size of 1.2 0.3 nm was achieved by employing sodium s - dodecylthiosulfate as a ligand precursor during the modified brust schiffrin reaction. transmission electron microscopy (tem) of the isolated ir nanoparticles revealed a high degree of monodispersity. further characterizations with 1h nmr, ft - ir, uv vis spectroscopy, thermogravimetric analysis (tga), and x - ray photoelectron spectroscopy (xps) confirmed that the synthesized ir nanoparticles are stabilized by dodecanethiolate ligands produced upon the adsorption / cleavage of s - dodecylthiosulfate on the growing ir nanoparticle surface. by comparison, synthetic attempts employing dodecanethiol as a stabilizing ligand led to the formation of ir - thiolate species (ir(sr)3) as an intermediate and ir - hydroxide species at the completion of reaction. mechanistic investigations of these two reactions using s - dodecylthiosulfate and dodecanethiol provided deeper understandings on the novelty of thiosulfate ligands, which allow the successful formation of stable thiolate - capped ir nanoparticles. moreover, these ir nanoparticles were shown to have strong magnetic properties. |
therapeutic laparoscopy was incorporated into the practice of general surgery more than 25 years ago. since that time, several modifications to minimally invasive access and surgery have been developed with the purpose of further minimizing surgical trauma and improving results : minilaparoscopy, computer - assisted robotic surgery, single - incision laparoscopic surgery, and natural orifice surgery. the lack of clear improvement in overall safety, effectiveness, and value has kept these other approaches from replacing conventional laparoscopy. smaller diameter (23 mm) instruments, trocars, and scopes for use in procedures usually termed minilaparoscopy were introduced in the mid 1990s. minilaparoscopy was promoted to minimize scarring, reduce postoperative pain, improve visualization in small fields, and improve surgical results, but it failed to become mainstream for a variety of reasons. renewed interest in this approach has developed recently on the part of surgeons and medical device companies. significant effort is being devoted to improving the ease of use, functionality, quality, and durability of minilaparoscopic instruments. a novel design of mini instruments was recently developed and precisely manufactured to minimize friction between instruments and trocars (0.1 n vs. 4.3 n), based on exact experimentally determined optimal tolerances (minimal gap between trocar and instrument) and absence of trocar valves. we conducted a study to evaluate these new low - friction mini instruments, comparing them to both 3-mm mini instruments and 5-mm traditional instruments, in a standardized set of simulation exercises. the authors submitted the proposal for this study to the institutional review board at the university of pernambuco, and a full exemption was provided, with consideration that the study subjects were medical students and residents working in a dry lab setting, with no patients or patient data involved. study participants were selected by testing surgical novices (medical students) and individuals with beginner intermediate surgical experience (postgraduate year [pgy]-1 and -2 surgical residents) ; excluding participants with known visual, motor, or other impairment ; excluding participants with prior advanced training in conventional or minilaparoscopy (experts) ; and training all study participants on all instrument designs, with at least 2 h of training occurring on 2 separate days. we opined that the results would be cleaner and easier to interpret if we excluded surgeons who could have been expert in the use of any of the 3 instrument designs. including an expert in the use of any of the instruments could have biased that group toward that instrument, thus potentially confounding any actual differences attributable to the design. based on pilot studies, it was determined that 22 medical students and 22 surgical residents would provide an adequate sample size to detect a difference in instrument performance (power, 80% ; confidence level, 95% ; win episcope version 2.0 statistical software ; developed by the veterinary faculty, university of zaragoza, spain, and the department of animal husbandry, wageningen agricultural university, the netherlands). the surgical simulator was selected for its recognized applicability, portability, and ease of use (prodelphus e - knot, olinda, brazil) (figure 1a). four standardized tasks were selected to simulate grasping, 2-handed movement, manipulation, and suturing, respectively : bean collection grasping and moving 5 beans, one by one, into a bowl ; small rings passing a suture through 5 variously oriented fixed metal rings (eye bolts) ; pearl necklace2-handed threading of a suture through four beads to create a necklace ; and suture and knot passing a curved needle and suture through a laceration in a penrose drain, using a simple suture technique and a single square knot, with a 15-cm - long 5 - 0 polyglactin suture (vicryl ; ethicon, sao paulo, brazil) (figure 2). a, the surgical simulator used for the 4 tasks (prodelphus e - knot, olinda, brazil). b, c, photographs of the 5-mm conventional laparoscopic instruments, 3-mm mini instruments, and 3-mm low - friction mini instruments (karl storz endoscopy, tuttlingen, germany). b1, 5-mm needle - holder ; b2, 5 mm grasper forceps ; b3, 5-mm maryland forceps ; b4, 3-mm needle holder ; b5, 3-mm grasper forceps ; b6, 3-mm maryland forceps ; c7, 3.5-mm - diameter, 15-cm - long low - friction mini trocar ; c8, 3.8-mm - diameter, 15-cm - long conventional mini trocar ; and c9, 6-mm diameter, 10.5-cm - long laparoscopic trocar. four standardized tasks were selected to simulate grasping, 2-handed movement, manipulation, and suturing, respectively : a, collect beans grasping and moving five beans, one by one, into a bowl ; b, small rings passing a suture through 5 variously oriented and fixed metal rings (eye bolts) ; c, pearl necklace2-handed threading of a suture through 4 beads to create a necklace ; and d, suture and knot passing a curved needle and suture through a laceration in a penrose drain, using a simple suturing technique and a single square knot with a 15-cm - long 5 - 0 polyglactin suture. the conventional laparoscopic instruments (5 mm) and trocars (6 mm) and the conventional - friction mini instruments (3 mm) and trocars (3.8 mm) are commercially available from karl storz endoscopy (tuttlingen, germany). the low - friction configuration was created by replacing the conventional mini trocars with the new low - friction valveless trocars and retaining the same 3-mm mini instruments (figure 1b, c). to increase precision of movement and decrease surgical stress for the surgeon and the patient during minilaparoscopic procedures, no seal or valve is used with the novel low - friction trocars, thus minimizing (essentially eliminating) the usual friction forces between trocar and instrument. the special trocar was designed to resemble a long needle, with very precise tolerances matching exactly the diameter of the corresponding 3-mm instruments. with this trocar system, the space between the instrument and the trocar is minimal, thereby eliminating the need for a rubber seal or valve to prevent gas loss. these low - friction mini trocars (3.5 mm) are also commercially available from karl storz endoscopy. for each of the 3 instrument lines, the following instruments were chosen for use in this study : grasping forceps, curved maryland dissectors, and needle drivers. the exercises were performed with the surgical trainer placed on a surgical table in a hospital operating room (university hospital oswaldo cruz, recife, brazil). they were randomly assigned to perform each of the 4 standardized tasks, with each of the 3 sets of instruments (5-mm, mini, and low - friction mini) used in random order. the order of tasks and instruments was randomized to avoid potential confounding by serial performance or learning effects. data analysis was performed by two independent consultant biostatisticians who had no interest in the study outcome (ulisses ramos montarroyos, university of pernambuco ; jose edmilson mazza batista, federal university of pernambuco). before the study was conducted, we decided to analyze the results for the 22 medical students and the 22 surgical residents as 2 separate groups. the biostatisticians recommended that all 5 replicates for each exercise instrument combination be included in the analysis (there were insufficient outlier values to exclude highest and lowest values). the data are graphically presented as mean (sd) for each exercise instrument participant group combination. paired samples were compared by student 's t test, = 0.05 (stata, version 12.0 ; statacorp, college station, texas). the authors submitted the proposal for this study to the institutional review board at the university of pernambuco, and a full exemption was provided, with consideration that the study subjects were medical students and residents working in a dry lab setting, with no patients or patient data involved. study participants were selected by testing surgical novices (medical students) and individuals with beginner intermediate surgical experience (postgraduate year [pgy]-1 and -2 surgical residents) ; excluding participants with known visual, motor, or other impairment ; excluding participants with prior advanced training in conventional or minilaparoscopy (experts) ; and training all study participants on all instrument designs, with at least 2 h of training occurring on 2 separate days. we opined that the results would be cleaner and easier to interpret if we excluded surgeons who could have been expert in the use of any of the 3 instrument designs. including an expert in the use of any of the instruments could have biased that group toward that instrument, thus potentially confounding any actual differences attributable to the design. based on pilot studies, it was determined that 22 medical students and 22 surgical residents would provide an adequate sample size to detect a difference in instrument performance (power, 80% ; confidence level, 95% ; win episcope version 2.0 statistical software ; developed by the veterinary faculty, university of zaragoza, spain, and the department of animal husbandry, wageningen agricultural university, the netherlands). the surgical simulator was selected for its recognized applicability, portability, and ease of use (prodelphus e - knot, olinda, brazil) (figure 1a). four standardized tasks were selected to simulate grasping, 2-handed movement, manipulation, and suturing, respectively : bean collection grasping and moving 5 beans, one by one, into a bowl ; small rings passing a suture through 5 variously oriented fixed metal rings (eye bolts) ; pearl necklace2-handed threading of a suture through four beads to create a necklace ; and suture and knot passing a curved needle and suture through a laceration in a penrose drain, using a simple suture technique and a single square knot, with a 15-cm - long 5 - 0 polyglactin suture (vicryl ; ethicon, sao paulo, brazil) (figure 2). a, the surgical simulator used for the 4 tasks (prodelphus e - knot, olinda, brazil). b, c, photographs of the 5-mm conventional laparoscopic instruments, 3-mm mini instruments, and 3-mm low - friction mini instruments (karl storz endoscopy, tuttlingen, germany). b1, 5-mm needle - holder ; b2, 5 mm grasper forceps ; b3, 5-mm maryland forceps ; b4, 3-mm needle holder ; b5, 3-mm grasper forceps ; b6, 3-mm maryland forceps ; c7, 3.5-mm - diameter, 15-cm - long low - friction mini trocar ; c8, 3.8-mm - diameter, 15-cm - long conventional mini trocar ; and c9, 6-mm diameter, 10.5-cm - long laparoscopic trocar. four standardized tasks were selected to simulate grasping, 2-handed movement, manipulation, and suturing, respectively : a, collect beans grasping and moving five beans, one by one, into a bowl ; b, small rings passing a suture through 5 variously oriented and fixed metal rings (eye bolts) ; c, pearl necklace2-handed threading of a suture through 4 beads to create a necklace ; and d, suture and knot passing a curved needle and suture through a laceration in a penrose drain, using a simple suturing technique and a single square knot with a 15-cm - long 5 - 0 polyglactin suture. the conventional laparoscopic instruments (5 mm) and trocars (6 mm) and the conventional - friction mini instruments (3 mm) and trocars (3.8 mm) are commercially available from karl storz endoscopy (tuttlingen, germany). the low - friction configuration was created by replacing the conventional mini trocars with the new low - friction valveless trocars and retaining the same 3-mm mini instruments (figure 1b, c). to increase precision of movement and decrease surgical stress for the surgeon and the patient during minilaparoscopic procedures, no seal or valve is used with the novel low - friction trocars, thus minimizing (essentially eliminating) the usual friction forces between trocar and instrument. the special trocar was designed to resemble a long needle, with very precise tolerances matching exactly the diameter of the corresponding 3-mm instruments. with this trocar system, the space between the instrument and the trocar is minimal, thereby eliminating the need for a rubber seal or valve to prevent gas loss. these low - friction mini trocars (3.5 mm) are also commercially available from karl storz endoscopy. for each of the 3 instrument lines, the following instruments were chosen for use in this study : grasping forceps, curved maryland dissectors, and needle drivers. the exercises were performed with the surgical trainer placed on a surgical table in a hospital operating room (university hospital oswaldo cruz, recife, brazil). they were randomly assigned to perform each of the 4 standardized tasks, with each of the 3 sets of instruments (5-mm, mini, and low - friction mini) used in random order. the order of tasks and instruments was randomized to avoid potential confounding by serial performance or learning effects. data analysis was performed by two independent consultant biostatisticians who had no interest in the study outcome (ulisses ramos montarroyos, university of pernambuco ; jose edmilson mazza batista, federal university of pernambuco). before the study was conducted, we decided to analyze the results for the 22 medical students and the 22 surgical residents as 2 separate groups. the biostatisticians recommended that all 5 replicates for each exercise instrument combination be included in the analysis (there were insufficient outlier values to exclude highest and lowest values). the data are graphically presented as mean (sd) for each exercise instrument participant group combination. paired samples were compared by student 's t test, = 0.05 (stata, version 12.0 ; statacorp, college station, texas). the results are summarized in table 1 and are presented graphically in figure 3, with means and standard deviations shown for every task instrument participant combination. for all 4 tasks, the instrument design that performed the best was the same for both the medical student group and the surgical resident group. for the bean - collection gross - grasping exercise, the 5-mm instruments performed best, followed by the low - friction mini instruments. for the other 3 more complex and precise exercises small rings, pearl necklace, and suturing and knot the low - friction mini instruments performed best, followed by the conventional mini instruments. time to completion of the 4 tasks average times are shown in seconds (mean sd) for the 3 laparoscopic instrument designs : 5-mm conventional laparoscopy, 3-mm conventional minilaparoscopy, and 3-mm low - friction minilaparoscopy. the results of all comparisons conventional vs. conventional mini, conventional vs. low - friction mini, and conventional mini vs. low - friction mini average times for both participant groups are shown in seconds (mean, sd) for the 3 different laparoscopic instrument designs : 5-mm conventional, 3-mm conventional mini, and 3-mm low - friction mini. all comparisons (conventional vs. conventional mini, conventional vs. low - friction mini, and conventional mini vs. low - friction mini) showed significant differences for all 4 tasks. the potential advantages of minilaparoscopy are apparent and applicable to multiple stakeholders. to patients, the advantages of minilaparoscopy over traditional laparoscopy seem clear : smaller incisions, less scaring, and reduced postoperative pain. for surgeons, the transition from conventional laparoscopy to minilaparoscopy is intuitive : trocar and instrument positions are preserved, triangulation is maintained, operative technique is the same or similar, and the technical challenges inherent to natural orifice and single incision approaches are avoided. for payers and hospitals, there is no need to purchase giant equipment, and operating room costs are lower. clinical studies have demonstrated some advantages of minilaparoscopy in technical feasibility, safety, effectiveness, and cost effectiveness for certain procedures. for laparoscopic cholecystectomy (lc), sajid concluded in a meta - analysis that mini - lc results in less postoperative pain and better cosmesis than does conventional lc ; lima found a lower bile duct injury rate with mini - lc ; and carvalho demonstrated reduced hospital costs for clipless mini - lc. for laparoscopic inguinal hernia repair performed by using a mini technique, lau and lee found, in a prospective comparative study, less postoperative pain, and carvalho found a shorter operative time. for transanal endoscopic microsurgery (tem), araujo concluded that mini instruments provide improved visualization in this limited working space compared to conventional 5-mm instruments. improved visualization within in a small space may have contributed to the better results for the suturing task in this study. as we can see, in the endoscopic view, visualization was improved with the 3-mm mini instruments versus that attained with the 5-mm instruments at the same vantage point (figure 4). other clinical studies have found minilaparoscopy and conventional laparoscopy to yield similar outcomes. for mini - lc, for mini- versus conventional laparoscopic appendectomy, sajid found similar perioperative outcomes and hospital stay. for hysterectomy, ghezzi found no difference in postoperative pain with mini- versus conventional laparoscopy. none of these investigators used low - friction mini instruments, and none found standard - friction mini instruments to be inferior to conventional 510-mm laparoscopic instruments. endoscopic views taken by a 10-mm 30 scope (karl storz) of the suture - and - knot task. photographs were taken at exactly the same vantage point for (a) 5-mm and (b) 3-mm instruments. the better visualization obtained with the mini instruments can be observed. why has minilaparoscopy failed to become more mainstream ? in an elegant study in a dry lab, rosser showed a decrease in the performance of laparoscopic surgeons when using early minilaparoscopic instruments when compared with traditional laparoscopic instruments. early generations of 2- to 3-mm laparoscopic instruments had several mechanical limitations, including instrument bending, lack of insulation and electrocautery, suboptimal effector tip functionality, and poor durability. as computer - assisted robotic surgery, single - incision laparoscopy, and natural orifice surgery appeared, but then struggled to replace conventional laparoscopy, a renewed interest developed in minilaparoscopy, causing surgeon - innovators and industry leaders to begin developing newer generations of mini instruments with improved performance. the new low - friction trocars consist of an outside part, such as a needle, but are longer than the traditional mini trocars. the insert, with a progressively dilating tip and minimal gap, causes less damage to muscle layers and skin during insertion than do traditional trocars. to facilitate placement, the insert fits very firmly into a luer lock connector type that can also be used for suction or gas inflation and is specially useful for creating the retroperitoneal space for totally extraperitoneal (tep) hernia repair and lumbar sympathectomy. research and development of these devices revealed that very narrow, exact clearances between precisely manufactured instruments and trocars would allow for the elimination of the co2 valve from the trocar. doing so resulted in a decrease in instrument friction from 4.3 to 0.13 n, with minimum leakage of co2 (0.1 l / min). early bench model tests of these low - friction mini instruments noted favorable surgeon perceptions. the notable reduction of the friction forces between the trocar and the mini instruments results in less trocar movement and fewer trocar dislocations from the abdominal wall, which should reduce abdominal wall trauma and contribute to improved cosmetics results. the experimental study reported herein was undertaken to test these low - friction instruments objectively, in a variety of simulated laparoscopic tasks, compared to both conventional minilaparoscopic instruments and conventional 5-mm instruments. in this study, for the bean - collection task (a simple gross - movement exercise), the larger effector tips of the 5-mm instruments appeared to have the advantage over the smaller effector tips of the mini instruments. it is of interest, however, even with this task, that the low - friction mini instruments outperformed the conventional - friction mini instruments. for the other 3 tasks, all of which require 2-handed precise movements, the low - friction mini instruments outperformed either of the other 2 designs. in these experimental models, the low - friction design seemed to offer an advantage for precise coordinated surgical movements. whether this same advantage will be observed with the clinical application of these low - friction trocars remains to be seen. some early results from their application to mini - lc suggest that it may. the limitations of this study include those inherent in simulator - based basic research. the participants (intentionally) included novices, beginners, and those with intermediate experience, not specialists in minimally invasive surgery. metrics were time based only, with no metrics for efficiency of movement, surgeon ergonomics, or surgeon perception of the experience. finally, the simulated surgical tasks were of various levels of complexity, but still were less complex than the human surgical experience. in standard surgical simulator exercises, low - friction minilaparoscopic instruments outperformed both conventional 3- and 5-mm laparoscopic instruments in executing precise tasks. | background and objectives : therapeutic laparoscopy was incorporated into surgical practice more than 25 y ago. several modifications have since been developed to further minimize surgical trauma and improve results. minilaparoscopy, performed with 2- to 3-mm instruments was introduced in the mid 1990s but failed to attain mainstream use, mostly because of the limitations of the early devices. buoyed by a renewed interest, new generations of mini instruments are being developed with improved functionality and durability. this study is an objective evaluation of a new set of mini instruments with a novel low - friction design.method:twenty-two medical students and 22 surgical residents served as study participants. three designs of laparoscopic instruments were evaluated : conventional 5 mm, traditional 3 mm, and low - friction 3 mm. the instruments were evaluated with a standard surgical simulator, emulating 4 exercises of various complexities, testing grasping, precise 2-handed movements, and suturing. the metric measured was time to task completion, with 5 replicates for every combination of instrumentexerciseparticipant.results:for all 4 tasks, the instrument design that performed the best was the same in both the medical student and surgical resident groups. for the gross - grasping task, the 5-mm conventional instruments performed best, followed by the low - friction mini instruments. for the 3 more complex and precise tasks, the low - friction mini instruments outperformed both of the other instrument designs.conclusion:in standard surgical simulator exercises, low - friction minilaparoscopic instruments outperformed both conventional 3- and 5-mm laparoscopic instruments for precise tasks. |
artificial oxygen carriers aim at improving oxygen transport and oxygen unloading to the tissue. artificial oxygen carriers may thus be used as an alternative to allogeneic blood transfusions or to improve tissue oxygenation and function of organs with marginal oxygen supply. the present article describes the currently evaluated perfluorocarbon emulsions, in order to summarize their efficacy, discuss potential side effects and illustrate potential future applications. perfluorochemicals are chemically inert synthetic molecules that consist primarily of carbon and fluorine atoms, and are clear, colourless liquids. they have the ability to physically dissolve significant quantities of many gases including oxygen and carbon dioxide. perfluorochemicals thus have to be emulsified for intravenous use. with sophisticated technology, it is possible to generate a stable perfluorocarbon emulsion with exceptionally small particles (median diameter 0.2 m diameter) and cause only mild temperature increases and mild flu - like symptoms in relatively few individuals. once in the res, excretion depends on vapor pressure and lipid solubility of flourocarbons. elimination half - time is 3 - 4 days for perfluorooctyl bromide and 8 days for perfluorodichlorooctane. because flourocarbon molecules are inert to biochemical degradation, they diffuse back into the blood where they dissolve in plasma lipids. these lipids transport the perfluorocarbon molecules to the lungs where they are excreted by exhalation. at higher doses (1.7 g / kg oxyfluor, 1.8 g / kg oxygent) a transient decrease in platelet count was observed 2 - 3 days after dosing, with recovery by 7 - 14 days. with oxygent, however, the decrease in platelet count was mild (10 - 20 %) and no drug - related effects on platelet function were observed. furthermore, plasmatic coagulation was not compromised and template bleeding time was not prolonged by 1.8 g / kg oxygent. in addition, there was no complement activation ; no suppression of humoral or cell - mediated immune function ; no haemodynamic effects or vasoconstriction ; no changes in liver, lung or renal function ; and no clinically relevant effects on blood chemistry. oxygen transport characteristics of perfluorocarbon emulsions are fundamentally different from those of blood (fig. in contrast, perfluorocarbon emulsions are characterized by a linear relationship between oxygen partial pressure and oxygen content. elevated arterial oxygen partial pressures are thus beneficial to maximize the oxygen transport capacity of perfluorocarbon emulsions. ventilation with 100% oxygen may raise concerns regarding oxygen toxicity. during relatively short exposure times (< 8 h), however, no evidence of oxygen toxicity was detected and the earliest signs of oxygen toxicity were observed only after 18h. red blood cells are flexible, disk - shaped cells approximately 7 - 8 m in diameter and are packed with highly concentrated hemoglobin. in arterioles red cells fill most of the vessel diameter with a relatively small plasma phase near the vessel wall where smaller cells such as platelets (1 m in diameter) and small particles concentrate (near - wall particle excess phenomenon). in the capillaries the distance between red blood cells increases, producing significant intercellular plasma gaps, and capillaries are found that are perfused by plasma only. due to the small size (< 0.2 m in diameter) perfluorocarbon emulsion particles mainly flow in the peripheral plasma layer in larger vessels. in the microcirculation, perfluorocarbon emulsion particles perfuse even the tiniest capillaries (4 - 5 m in diameter), where no red blood cells may flow under certain conditions. it is precisely this area in which perfluorocarbon emulsions exert their greatest effects, because they augment local oxygen delivery much more than would be expected from the increase in oxygen content in the arterial blood (large vessel with red blood cells). another important aspect that determines the efficacy of perfluorocarbon emulsions is the fact that all oxygen carried by the perfluorocarbon is in the dissolved state, resulting in a higher oxygen partial pressures in the microcirculation and thereby augmenting the driving pressure for the diffusion of dissolved oxygen into the tissue. a perflubron emulsion (oxygent) was assessed in a variety of haemodilution studies. keipert applied perflubron emulsion in dogs after acute normovolemic haemodilution (anh) at a haematocrit of 10%. with the application of oxygent, cardiac output tended to increase and a massive rise in mixed venous oxygen partial pressure and mixed venous saturation was observed. the percentage of metabolized oxygen that originated from endogenous haemoglobin decreased with the application of oxygent, indicating that the oxygen transported by oxygent is preferentially metabolized, due to its excellent oxygen unloading characteristics. an increase in mixed venous oxygen partial pressure indicates improvement in global oxygenation status, rather than shunting of oxygen from arterioles directly into venules (i.e. oxygen bypassing the microcirculation). this view is substantiated by a study that demonstrated an increase of oxygen consumption in a maximally working, in - situ gastrocnemius muscle preparation in anesthetized and haemodiluted dogs after oxygent administration. it is also substantiated by the fact that increases in mixed venous oxygen partial pressure are generally associated with an oxygent - dependent improvement in tissue oxygenation, as demonstrated in the heart, brain, muscle, gut and liver. furthermore, holman tested oxygent in severely haemodiluted dogs undergoing cardiopulmonary bypass. dogs treated with increasing doses of oxygent survived cardiopulmonary bypass progressively better than did control animals. oxygent may also be beneficial as an adjunct to resuscitation. in a porcine model of near fatal haemorrhage, infusion of oxygenated oxygent into the aortic arch also improved outcome in another resuscitation model. mixed venous oxygen partial pressure was higher in oxygent - treated animals after anh to a haemoglobin of 7 g / dl than in control animals, and measures of left ventricular systolic and diastolic contractile function were found to be improved after oxygent administration at a haemoglobin level of 3 g / dl. this might be explained by an augmented oxygen delivery through very narrow capillaries where oxygent particles may penetrate better than the relatively large red blood cells, and thereby improve local tissue oxygenation more than red blood cells. these studies thus indicate that oxygent indeed transports and unloads oxygen into the areas where it is needed most. anh to a haemoglobin concentration of approximately 9 g / dl was performed. during surgery oxygent (0.9 g / kg) was administered when a blood transfusion was deemed necessary by the anaesthesiologist, which occurred at a haemoglobin concentration of approximately 8 g / dl. mixed venous oxygen tension and mixed venous oxygen saturation both increased significantly after oxygent administration, and cardiac output was stable. although only relatively little oxygen was transported by perflubron emulsion (approximately 1%), 5% of the metabolized oxygen was transported by oxygent, again indicating that oxygent - transported oxygen is preferentially metabolized. recently, the results of two large prospective randomized multicenter studies on the use of oxygent in orthopaedic and genitourinary surgery were presented. in the orthopaedic study, 147 patients undergoing hip replacement and spine surgery were haemodiluted preoperatively to a hemoglobin level of 9 g / dl. after the patients had reached a predefined transfusion trigger, they were randomized into four groups : standard of care (retransfusion of 450 ml autologous blood at an unchanged fractional inspired oxygen of 0.4) ; oxygent (0.9 or 1.8 g / kg) with colloid to a total 450 ml with ventilation with an fractional inspired oxygen of 1.0 ; and infusion of 450 ml colloid with ventilation with an fractional inspired oxygen of 1.0. oxygent (1.8 g / kg) was most successful in reversing transfusion triggers in 97% of patients, as compared with 60% in the control group. the duration of transfusion trigger reversal in the oxygent 1.8 g / kg group was significantly longer (80 min) than in the control and colloid groups (55 and 30 min, respectively). in the study that including 109 patients undergoing genitourinary surgery, similar results were achieved. thus, physiologic transfusion triggers may be treated at least as successfully with oxygent as with autologous blood of colloids. this illustrates the remarkable potency of oxygent to deliver readily available oxygen to those areas in the body in which the extra oxygen is needed most. optimal use of perfluorocarbon emulsions in the future may consist of a combination of anh preoperatively with application of an artificial oxygen carrier such as a perfluorocarbon emulsion during the operation, a procedure termed ' augmented anh ' [roth dj, keipert pe, faithfull ns, zuck tf, riess jg : facilitated oxygen delivery in conjunction with hemodilution. us patent # 5,451,205 (issued september 19, 1995) and european patent # ep 0627 913 b1 (issued april 4, 1998) ] (fig. augmented anh is a concept in which patients undergo anh to relatively low haemoglobin levels preoperatively. during the operation, when the haemoglobin concentration decreases further due to surgical blood loss and concomitant colloid or crystalloid replacement, perfluorocarbon emulsions in conjunction with 100% oxygen ventilation is administered to enhance oxygen delivery and improve tissue oxygenation. as a consequence, lower levels of haemoglobin concentration can be safely tolerated. towards the end of the operation, this will result in a relatively high haemoglobin concentration in the postoperative period and oxygen delivery will again be provided by endogenous haemoglobin. therefore, greatly elevated arterial partial oxygen tension values are not necessary in the postoperative period and the relatively short half - life of perfluorocarbon emulsions (< 24 h) will not compromise their success in reducing allogeneic blood transfusion requirement (fig., it is important not to compromise blood coagulation during the surgical procedure, otherwise blood loss might be enhanced and thus allogeneic blood savings limited. therefore, a careful selection of colloids is necessary to avoid blood coagulation becoming compromised. apart from the use of perfluorocarbon emulsions to reduce allogeneic blood transfusions in surgery, there are numerous other potential future indications based on their potential to augment tissue oxygenation. such future indications will probably include treatment and prevention of cerebral ischaemia, stroke, cardiopulmonary bypass - related cerebral adverse events, spinal cord ischaemia, myocardial ischaemia due to acute infarction, percutaneous coronary angioplasty, acute limb ischaemia, emergency surgery and trauma as long as no allogeneic blood is available, and decompression sickness. other applications include the use of perfluorocarbon emulsions to augment tumour oxygenation to render them more sensitive to radiation and chemotherapy, to prevent or treat sequelae of air embolism, and finally to improve organ preservation for subsequent organ transplantation (referenced in). perfluorocarbon emulsion and blood - based oxygen transport : oxygen dissociation curve of native human blood (blood) and a perfluorocarbon (pfc) emulsion. note that 5 volume % (5 vol%) of oxygen can be offloaded by blood as well as by a pfc emulsion. with a pfc emulsion, higher note also that pfc emulsion - transported oxygen is more completely offloaded than blood - transported oxygen, resulting in an approximate oxygen extraction (o2-ex.) ratio of 90% for the pfc emulsion, as compared with approximately 25% for blood, assuming a normal mixed venous partial oxygen tension of approximately 40 mmhg. c o2, oxygen content ; po2, partial oxygen tension. modified according to looker and keipert). the concept of augmented acute normovolemic haemodilution (a - anh) is divided into three periods (a - c). (a) preoperative anh with conventional volume replacement without the use of an artificial oxygen carrier such as a perfluorocarbon emulsion. preoperative anh targets relatively low hemoglobin levels, close to the individual transfusion trigger. (b) during surgery when the haemoglobin concentration is expected to fall further due to surgical blood loss, a perfluorocarbon emulsion will be used to augment oxygen - offloading capacity to the body. note that total oxygen offloading capacity from combined haemoglobin - based and perfluorocarbon emulsion - based oxygen transport is maintained during surgery at the level reached after preoperative anh (ie above the individual transfusion trigger, despite low haemoglobin concentrations towards the end of surgery).(c) postoperative retransfusion (postop. rt) of anh blood increases the haemoglobin concentration above the individual transfusion trigger. therefore, the decreasing contribution of pfc emulsion - based oxygen transport will not adversely affect overall oxygenation of the organism. | perfluorocarbon emulsions are being clinically evaluated as artificial oxygen carriers to reduce allogeneic blood transfusions or to improve tissue oxygenation. perfluorocarbon emulsions are efficacious in animal experiments, and in humans they are well tolerated and at least as successful to reverse physiologic transfusion triggers than autologous blood. perfluorocarbon emulsions may be used in the future in the concept of augmented acute normovolaemic haemodilution. in this concept relatively low preoperative haemoglobin levels are targeted during preoperative normovolaemic haemodilution and a perfluorocarbon emulsion is given to augment oxygen delivery during surgery when low endogenous haemoglobin levels are expected. the autologous blood is subsequently retransfused in the postoperative period when the patient 's oxygenation is provided primarily by the endogenous haemoglobin. additional uses of perfluorocarbon emulsions will include treatments of diseases with compromised tissue oxygenation such as cerebral or myocardial ischaemia, air embolism and emergency or trauma surgery as long as no allogeneic blood is available. |
the skin is continuously exposed to a wide variety of chemical and physical insults and other environmental factors, and therefore, is prone to neoplastic proliferation. in dogs, approximately 30% of all neoplasms the incidence of cutaneous tumors in dogs is estimated to be 728 cases every year per 100,000 dogs. in the last five years of our experience, the number of canine cutaneous biopsy specimens sent to our laboratory has increased, and new protocols for the management and treatment of these neoplasms have been introduced and adjusted in recent years. information on the prevalence and distribution of individual cutaneous tumors helps veterinary practitioners to diagnose them in time, determine an appropriate therapy, and anticipate an adequate prognosis. for example, a major advantage of standard surgical excision of skin tumors is completeness of surgery, which can only be determined by histopathology. a basic prerequisite for proper diagnosis, appropriate therapy, and adequate prognosis is a valid classification of cutaneous neoplasms. skin tumors are generally classified histologically according to the tissue of origin (epithelial cell and mesenchymal cell) and individual cells of origin (round cell and spindle cells) if sufficient differentiation is present. tumors are further classified in terms of the degree of malignancy based on several histologic characteristics, such as the mitotic index and degree of cellular or nuclear atypia. therefore, to establish a uniformity and valid classification of cutaneous neoplasms, the world health organization (who) introduced a new classification of skin tumors in 1999. the need for retrospective analysis and reclassification of cutaneous tumors according to recent who classification is particularly important. classification based on the recent who standards is a prerequisite for precise diagnosis, and may provide an appropriate therapeutic and prognostic approach to the problem. reports on the prevalence, tumor predilection sites, sex, breed, and age of the canine cutaneous tumors have been published previously [1,6,8 - 13,15 ]. the results of those studies were considerably variable, which could be attributed primarily to geographical location, prevalent environmental influences, and breed populations [1,8,10 - 12,14 ]. this study aims to determine the relative prevalence and distribution of several types of canine skin tumors in our bioptic samples, which were received and analyzed between january 2003 and june 2006. we anticipate that the result of this study will be valuable for veterinary practitioners in their practices. to our knowledge, this kind of information has not been published previously for the korean canine population. a total of 3,069 canine biopsy and necropsy specimens were submitted to the department of veterinary pathology, college of veterinary medicine, seoul national university for diagnosis during the designated period (january 2003 to june 2006). the samples were received from the veterinary medical teaching hospital of seoul national university and veterinary practitioners across the nation. of these, 2,952 were biopsy specimens. among the biopsy specimens, 748 cases (25.34%) the tissues were fixed in 10% phosphate - buffered neutral formalin, routinely processed, paraffin embedded, and stained with hematoxylin and eosin (h&e). replicate sections of particular cases were also stained with special stains such as oil red o, giemsa, periodic acid - schiff and toluidine blue whenever they were needed to confirm the diagnosis. the skin tumors found in our material were categorized in three groups according to the recent who classification, namely, epithelial and melanocytic tumors, mesenchymal tumors of the skin, and hematopoietic tumors located in the skin. replicate sections of particular cases were subjected to immunohistochemistry whenever it was needed to decipher the cellular origin by applying a routine avidin - biotin - complex (abc) procedure (vectastain ; vector laboratories and histostain plus ; zymed laboratories, usa). commercially available antibodies such as cytokeratin (biogenex, usa), vimentin (dakocytomation, denmark), desmin (biogenex, usa), s-100 (dakocytomation, denmark), melan a (dakocytomation, denmark), neuron - specific enolase (dakocytomation, denmark), and other related tumor markers were used in this study. after deparaffinization, the sections were dipped in 3% hydrogen peroxide in methanol to block endogenous peroxidase activity. sections were then subjected to microwave antigen retrieval in a 0.01 m citrate buffer (ph 6.0) for 10 min at 750 watts power. the sections were allowed to cool, and were then blocked with a blocking serum for 1 h. after incubating tissue specimens with the primary antibodies overnight at 4, immuno - reaction complexes were detected using the abc procedure and visualized with 3, 3-diaminobenzidine tetrahydrochloride as the chromogen. a total of 3,069 canine biopsy and necropsy specimens were submitted to the department of veterinary pathology, college of veterinary medicine, seoul national university for diagnosis during the designated period (january 2003 to june 2006). the samples were received from the veterinary medical teaching hospital of seoul national university and veterinary practitioners across the nation. of these, 2,952 were biopsy specimens. among the biopsy specimens, 748 cases (25.34%) the tissues were fixed in 10% phosphate - buffered neutral formalin, routinely processed, paraffin embedded, and stained with hematoxylin and eosin (h&e). replicate sections of particular cases were also stained with special stains such as oil red o, giemsa, periodic acid - schiff and toluidine blue whenever they were needed to confirm the diagnosis. the skin tumors found in our material were categorized in three groups according to the recent who classification, namely, epithelial and melanocytic tumors, mesenchymal tumors of the skin, and hematopoietic tumors located in the skin. replicate sections of particular cases were subjected to immunohistochemistry whenever it was needed to decipher the cellular origin by applying a routine avidin - biotin - complex (abc) procedure (vectastain ; vector laboratories and histostain plus ; zymed laboratories, usa). commercially available antibodies such as cytokeratin (biogenex, usa), vimentin (dakocytomation, denmark), desmin (biogenex, usa), s-100 (dakocytomation, denmark), melan a (dakocytomation, denmark), neuron - specific enolase (dakocytomation, denmark), and other related tumor markers were used in this study. after deparaffinization, the sections were dipped in 3% hydrogen peroxide in methanol to block endogenous peroxidase activity. sections were then subjected to microwave antigen retrieval in a 0.01 m citrate buffer (ph 6.0) for 10 min at 750 watts power. the sections were allowed to cool, and were then blocked with a blocking serum for 1 h. after incubating tissue specimens with the primary antibodies overnight at 4, immuno - reaction complexes were detected using the abc procedure and visualized with 3, 3-diaminobenzidine tetrahydrochloride as the chromogen. during the 42 month study period, 748 (25.34%) cases were diagnosed as canine cutaneous tumors among a total of 2,952 canine biopsies. thirty - eight different types of cutaneous tumors were identified. among them, 21 different histological types were categorized into epithelial and melanocytic tumors (56.95%, 426/748), 15 were mesenchymal tumors (38.90%, 291/748), and 2 were hematopoietic tumors (4.14%, 31/748) located in the skin. among the top five tumors from the epithelial and melanocytic skin tumors group, epidermal and follicular cysts were most frequent at 22.30% (95/426), followed by basal cell tumors at 11.97% (51/426), sebaceous adenoma at 11.74% (50/426), sebaceous hyperplasia at 8.92% (38/426), and hepatoid gland adenoma at 6.34% (27/426), comprising a total of 61.27% (261/426) of all epithelial and melanocytic tumors. as a subgroup, sebaceous and modified sebaceous gland tumors were the most frequent at 27.70% (118/426), followed by cysts at 22.30% (95/426), tumors with adnexal differentiation at 13.38% (57/426), epithelial tumors without adnexal differentiation at 11.97% (51/426), tumor - like lesions at 8.92% (38/426), apocrine and modified apocrine gland tumors at 6.10% (26/426), and tumors of the epidermis at 5.40% (23/426). melanocytic tumors comprised 4.23% (18/426) of all epithelial and melanocytic tumors (table 1 & 3). similarly, among mesenchymal tumors of the skin, lipoma at 29.21% (85/291), mast cell tumors at 22.68% (66/291), cutaneous histiocytoma at 19.24% (56/291), fibroma at 7.22% (21/291), and hemangiopericytoma at 4.12% (12/291) were the top five cutaneous mesenchymal tumors in order, comprising a total of 82.47% (240/291) of all mesenchymal tumors of the skin (table 2 & 3). in the case of hematopoietic tumors located in the skin, only plasmacytoma (54.84% ; 17/31) and lymphoma (45.16% ; 14/31) were observed in our study (table 2). 1. the ten most frequently diagnosed tumors in order of prevalence, comprising 68.45% (512/748) of all cutaneous tumors diagnosed during the study period, are summarized in table 4. the site distributions of these ten frequent tumors were on the trunk (30.08% ; 154/512), head and neck (20.90% ; 107/512), extremities (19.14% ; 98/512), anal and perianal area (8.59% ; 44/512), and tail (3.91% ; 20/512) (table 5). when all types of tumors were considered together in the whole population (n = 646) however, among the top ten tumors, hepatoid gland adenoma and apocrine adenocarcinoma were more frequent among males and females, respectively. the age of the animals with the ten most frequent tumors ranged from 2 months to 19 years, with a mean of 8.3 years (table 4). this finding is closer to the average age of 7.94 years in the whole population (n = 748). epidermal and follicular cysts accounted for 12.70% of all of the tumors observed, which was in line with the finding of another group. the average age of the dogs affected with this tumor was 5.1 years, with a range of 4 months to 14 years. these tumors were most commonly located on the trunk (44.21%), extremities (18.95%), and head and neck (13.68%). basal cell tumors accounted for 6.82% of the total number of tumors observed (n = 748), which is in line with the findings of other authors. the average age of the dogs affected with this tumor was 7.8 years, with a range of 3 months to 12 years. these tumors were most commonly located on the head and neck (64.71%) and extremities (13.73%). sebaceous adenoma and sebaceous hyperplasia accounted for 6.68% and 5.08% of all tumors, respectively. the average age of the dogs affected with sebaceous adenomas was 10.3 years, with a range of 4 months to 16 years, while sebaceous gland hyperplasia was observed in dogs at an average age of 8.6 years, within a range of 1 to 15 years. while sebaceous adenoma was most commonly located on the head and neck (26.00%), trunk (22.00%), and extremities (20.00%), the outgrowths representing sebaceous gland hyperplasia were most frequently located on the head and neck (21.05%) and tail (21.05%). hepatoid gland adenoma accounted for 3.61% of the total number of tumors in our case. the average age of the dogs affected with this tumor was 11.5 years, with a range of 5 years and 4 months to 19 years. these tumors were predominantly located in the anal and perianal area (96.30%) and tail (3.70%). these tumors were more frequently found in males (70.37%) than females (11.11%). melanocytic tumors accounted for 2.40% of all tumors and 4.23% of all epithelial and melanocytic tumors. the average age of dogs affected with this tumor was 8.2 years, with a range of 2 to 14 years. these tumors were most prevalent on the head and neck (83.33%) and extremities (11.11%). the average age of the dogs affected with this tumor was 7.1 years, with a range of 1 to 17 years. these tumors were predominantly located on the trunk (61.18%), and extremities (9.41%). the average age of the dogs affected with this tumor was 7.4 years, with a range of 5 months to 16 years. these tumors were most commonly located on the extremities (40.91%), trunk (27.27%), and head and neck (18.18%). the average age of the dogs affected with this tumor was 3.2 years, with a range of 2 months to 16 years. these tumors were predominantly located on the extremities (35.71%), head and neck (30.36%), trunk (19.64%), and tail (1.78%). the average age of the dogs affected with this tumor was 9 years, with a range of 1 to 17 years. these tumors were most commonly located on the anal and perianal area (38.10%), trunk (23.81%), head and neck (14.29%), and extremities (14.29%). the average age of the dogs affected with this tumor was 9.9 years, with a range of 7 to 15 years. these tumors were most commonly located on the trunk (50%) and extremities (33.33%). a brief account of our findings for the top five tumors in epithelial and melanocytic tumors, mesenchymal tumors of the skin, and melanoma is presented below. the majority of the cutaneous tumors diagnosed in the present study were benign (69% ; 518/748) in nature, and this finding was in agreement with earlier reports. in terms of the follicular and epidermal cysts, our findings showed relatively different frequencies compared to those reported in earlier investigations. for basal cell tumors, our findings are similar to the findings of previous studies, and our observation of the mean age is close to that of a previous reports, 6 - 7 years. for sebaceous adenoma and sebaceous hyperplasia, our results were in agreement with previous reports, and our data for mean age is similar to the findings of other authors. sebaceous gland hyperplasia has been reported to occur in older animals, with a mean age of 9.1 years. our observations on the locations of sebaceous gland hyperplasia showed some variation in terms of the frequency of their distribution compared to that found in previous reports. our findings on the occurrence of hepatoid gland adenoma with respect to age, sex [5,6,14 - 16 ], and location [5,6,14 - 16 ] were similar to the findings of earlier workers. our findings on the prevalence of melanocytic tumors and on age are similar to those found in previous reports. for lipoma, our findings on age and tumor location were in line with the findings of earlier authors [5 - 7,14,15 ]. our findings on age and tumor location of mast cell tumors are similar to the earlier observations [4 - 7,14,15,17 ]. in cutaneous histiocytoma, our observations on age and tumor location are in agreement with the findings of earlier workers [5 - 7,14,15 ]. our findings on prevalence, age, and tumor location [5 - 7,14,15 ] of fibroma are similar to the findings of earlier workers. in the case of hemangiopericytoma, our findings on prevalence, age [11,14 - 16 ], and the sex predilection of these cutaneous tumors was not significantly different (male 48.92% versus female 51.08%) in 646 total cases. however, at the individual tumor level amongst the top ten most frequently diagnosed tumors, males were more affected by hepatoid gland adenoma, while females were more affected by apocrine adenocarcinoma. hepatoid gland tumors are associated with the androgen sex hormone ; hence, these were reported more frequently in male dogs than in female dogs, but there has been no report to prove the etiology of apocrine adenocarcinoma. we could not draw valid conclusions on the sex predilection for the other tumors diagnosed in the present study due to non - specified sex data for the population. the results of this study were also compared with those from the united states of america, the united kingdom, australia, and greece. mast cell tumors, hepatoid gland adenoma, lipoma, and cutaneous histiocytoma were reported to be the four most common skin tumors occurring in surveys carried out in the usa, uk, australia, and greece. our findings, except those for epidermal and follicular cysts, were consistent with the findings of the studies from the other countries. the discrepancies between our data and the data obtained in previous studies in terms of the relative incidence of these frequently diagnosed tumors may be attributed mainly to differences in the diagnostic criteria, the classification system that various workers used, the geographical locations and environmental influences, and the study population and breed. our study revealed that the skin tumors of dogs that are prevalent in other parts of the world are also prevalent in dogs in korea, but differ in the order of prevalence. our observation on the ages of the dogs affected by various skin tumors and anatomical locations indicates that there is no significant variation in these important parameters among korean dogs and dogs from other parts of the world. we could not examine or draw valid conclusions on the sex predilection for the top ten most frequently diagnosed tumors and breed predisposition in our overall population. this is partially due to a lack of information on the korean dog population, and also partially due to inadequate information for biopsy specimens that were submitted for diagnosis to our laboratory. it is important to provide detailed information and proper bioptic specimens when submitting samples for diagnosis. this should include the duration and rate of tumor growth, change in appearance over time, size, shape, color, consistency, tissue of origin such as epidermis, dermis, and subcutaneous, and the presence or absence of attachment with the underlying tissues [15 - 17 ]. it is essential to document the prevalence of various tumors in various geographic areas so that more definitive information may be accumulated for future use. documented knowledge on the type and incidence of tumors helps veterinary practitioners to determine an appropriate therapy and anticipate an adequate prognosis. after a careful clinical examination, consideration of documented information on age, sex, and breed type and the histopathological report, clinicians can diagnose tumors in a reasonable amount of time, determine and decide on an appropriate therapy, and anticipate an adequate prognosis for many patients. this study was entirely based on clinical cases submitted for diagnosis from the veterinary medical teaching hospital of seoul national university and veterinary practitioners across the nation. it was not based on random samples from a dog population, nor did we sample according to our own interest. therefore, we anticipate that the results of our study will reflect the prevalence and distribution of various cutaneous tumors in the korean dog population we anticipate that the result of our study would be useful for veterinary practitioners and veterinary students across the nation. to our knowledge, this kind of information has not been published previously for the korean dog population. | over the 42 month period from january 2003 to june 2006, a total of 2,952 canine biopsy specimens were received from the veterinary medical teaching hospital of seoul national university and from veterinary practitioners across the nation. out of these, 748 (25.34%) cases were diagnosed as canine cutaneous tumors in the department of veterinary pathology, college of veterinary medicine, seoul national university, korea. thirty - eight different types of cutaneous tumors were identified and categorized into epithelial and melanocytic tumors (56.95%), mesenchymal tumors (38.90%), and hematopoietic tumors (4.14%) located in the skin. among these, 69.25% were benign and 30.74% were malignant. the top ten most frequently diagnosed cutaneous tumors were epidermal and follicular cysts (12.70%), lipoma (11.36%), mast cell tumors (8.82%), cutaneous histiocytoma (7.49%), basal cell tumors (6.82%), sebaceous gland adenoma (6.68%), sebaceous gland hyperplasia (5.08%), hepatoid gland adenoma (3.61%), apocrine adenocarcinoma (3.07%), and fibroma (2.81%), in order of prevalence. they comprised 68.45% of all cutaneous tumors. these top ten cutaneous tumors were distributed on the trunk (30.08%), head and neck (20.9%), extremities (19.14%), anal and perianal area (8.59%), and tail (3.91%). the age of the dogs with the ten most frequent tumors had a mean age of 8.3 years, with a range of 2 months to 19 years. when all types of tumors were considered together in the entire population, there was no difference in incidence according to sex. |
totally subcutaneous intravascular portals (port - a - cath) are frequently used to administer chemotherapeutic agents. we present a case of port - a - cath fracture with distal embolization causing non - sustained ventricular tachycardia and its percutaneous retrieval. a 68-year old male with diabetes, hypertension and dyslipidemia controlled by medication and metastatic colon cancer to the liver was admitted to hospital for a non - flushing port - a - cath which had been inserted six years earlier to receive chemotherapy. upon questioning, his physical examination revealed blood pressure 142/64, pulse 64, body temperature 37c, and an arterial oxygen saturation of 98%. this demonstrated a catheter fracture at the first rib with extravasation of contrast at the site of insertion with the distal catheter fragment traversing the right atrium and the right ventricle with the tip within the right ventricular apex (fig. 1). a linogram demonstrating catheter fracture at the medial border of the first rib with extravasation of contrast material (single arrow). the proximal portion of the catheter is located in the right atrium crossing into the right ventricle (double arrow). injection of contrast into the port - a - cath caused left shoulder pain. during hospitalization, cardiac telemetry demonstrated non - sustained runs of both supraventricular as well as ventricular tachycardia (fig. the morphology changes as the catheter embolus moves through the right heart. given the ventricular arrhythmia, a decision was made to retrieve the catheter fragment. the patient was transferred to our catheterization laboratory where repeat fluoroscopy showed the distal catheter had embolized further into the left main pulmonary artery (fig. subsequent cardiac catheterization demonstrating the catheter had migrated into the left pulmonary artery (a). a gooseneck snare was placed over the distal end of the catheter embolus (b) and maneuvered through the right ventricle, inferior vena cava and femoral vein (c) where it was extracted. a right femoral vein approach was used and a 6 fr multipurpose catheter was placed into the pulmonary artery via a 7fr femoral introducer sheath. through this, a 0.014 - 180 cm grand slam coronary wire (abbott vascular, abbot park, il, usa) with a cinch was advanced and the multipurpose catheter removed. the port - a - cath embolus was snared with a 25 mm 6 fr. amplatz gooseneck snare kit (covidien, plymoth, mn, usa) and withdrawn out of the pulmonary artery, into the right ventricle, then the inferior vena cava, and removed through the femoral sheath (fig. 3d). a follow - upechocardiogram demonstrated no evidence of pulmonary hemorrhage or cardiac trauma. port - a - caths are widely used in the field of oncology. catheter fracture and embolization a case series of 333 port - a - cath insertions showed that catheter fractures and distal embolization occurred in 5 cases (1.5%) (1). aitkins. described a possible mechanism for subclavian port - a - cath fracture where compression between the clavicle and the first rib causes catheter fracture (2). they describe the pinch off sign where the caliber of the catheter narrows as it passes over the first rib. the most common presentation of catheter embolization is asymptomatic discovery on chest radiology, with other presentations including infra / supraclavicular swelling (3). to our knowledge, there has been only one previous description of ventricular tachycardia caused by port - a - cath fracture and embolization (3). in that case, there was an increase in ectopy when the patient changed position. in our case, the patient had an unusual presentation of palpitations and ventricular tachycardia, but given his malfunctioning port - a - cath, further imaging allowed the cause of the arrhythmia to be diagnosed. prompt removal of catheter fragments is preferred due to potential complications including pulmonary thromboembolism, cardiac perforation, cardiac arrest and endocarditis (4). a previous case series of 20 patients with asymptomatic catheter embolization and per cutaneous retrieval demonstrated successful retrieval in all cases : 16 with a snare and 4 using a basket retrieval system (5). interestingly, 2 cases had thrombus formation in the distal catheter similar to our case. in summary, port - a - cath fracture and distal embolization has been described in the literature. our case describes a rare yet potentially catastrophic complication of catheter embolization, i.e. symptomatic cardiac arrhythmia and in situ thrombosis with a catheter fragment in the pulmonary artery. given the subtle nature of the embolization and the potential complications, clinicians should be vigilant for catheter fracture and embolization. percutaneous removal has been shown to be a safe procedure, allowing for prompt removal of the embolized catheter fragments. | we describe the case of a patient with a previously placed port - a - cath who was admitted to hospital for new onset of non - flushing catheter and palpitations with ventricular tachycardia. a chest x - ray and a linogram showed a port - a - cath fracture and distal embolization into the right ventricle resulting in ventricular tachycardia. the catheter was removed percutaneously using a goose neck snare with no complications and resolution of the ventricular tachycardia. the removed segment demonstrated thrombus. prompt removal of the embolized catheter fragments should be undertaken given the subtle nature of the embolization and the potential complications. |
apocrine carcinoma, also known as apocrine - gland carcinoma and sweat - gland carcinoma comprises of a group of extremely rare, malignant tumor, which shows features of apocrine differentiation. the disease is primarily diagnosed in the fifth to seventh decade of life, with similar incidence in men and women and without racial predilection. the malignancy arises at the sites of apocrine glands, which have a relatively limited distribution in the body and are found in the axillae, the medial aspect of upper arm, areola, lateral aspects of the breasts, ear canals, eyelids, and anogenital region. patients usually present with a slow - growing, purple or red skin mass, which can be either firm or cystic in consistency. morphologically, the tumor is an adenocarcinoma with varying degrees of differentiation composed of cells with eosinophilic cytoplasm. characteristic histopathologic findings include decapitation secretion, a feature considered pathognomonic for apocrine differentiation, periodic - acid - schiff - positive material in the cells or lumen, and immunoreactivity with gross cystic disease fluid protein. normal apocrine glands and apocrine - gland adenomas are often found alongside the tumor and are occasionally infiltrated by carcinoma cells. apocrine - gland carcinoma spreads via both lymphatic and vascular routes, with metastatic disease found in regional lymph nodes, lungs, liver, and bone. approximately one - third of patients have regional lymph node involvement at diagnosis ; the incidence is higher in patients with higher grade tumors. the female breast can be conceived developmentally and morphologically as a modified apocrine gland and therefore breast carcinoma with apocrine features can be indistinguishable from cutaneous ac. breast parenchymal malignancy is more common than skin adnexal carcinoma, and therefore in a woman with a history of breast carcinoma it is customary to consider such a skin neoplasm the result of secondary spread unless it is possible to prove otherwise. the only curative therapy for localized apocrine - gland carcinoma involves wide local excision with regional lymph node dissection and consideration of postoperative radiotherapy in patients with moderately or poorly differentiated tumors. early diagnosis is, therefore, critical, and all patients with enlarging masses of unknown etiology in areas of apocrine glands should have excisional biopsies. the clinical course is characterized by a high incidence of local recurrence (28% in one report), which is often managed by resection and radiation therapy. however, no standard guidelines exist regarding appropriate schedules and doses due to the rarity of the diagnosis. metastatic disease to the lung, skin, bone, brain, and kidney has been described and the disease is invariably fatal at this stage. a 62-year - old asian male presented to a satellite hospital with the complaint of excessive tears for more than five years and left eye swelling for two months. initially, swelling was limited to the left eyelid but progressed rapidly to size of a tennis ball. orbital computed tomography (ct) scan demonstrated a localized left orbital mass with suspicion for a tumor. the biopsy revealed poorly differentiated adenocarcinoma with polygonal tumor cells with large, hyper - chromatic nuclei, prominent nucleoli and abundant eosinophilic cytoplasm (figures 12). the pathognomic findings of the decapitation secretion (figure 1) and immunoreactivity with gross cystic disease fluid protein (figure 2) supported the diagnosis of apocrine adenocarcinoma of skin. figure 1skin with infiltrating tumor composed of complex glandular structures within dermis (hematoxylin and eosin staining). skin with infiltrating tumor composed of complex glandular structures within dermis (hematoxylin and eosin staining). he presented again after several months with progressively increasing facial deformity and inability to open his left eye. the physical examination revealed significant periorbital erythema with significant sero - sanguineous discharge from the skin lesion. metastatic survey with a bone scan unfortunately revealed multiple areas of uptake throughout the left orbital area. ct head and neck demonstrated a solid mass lesion in the medial part of left lower eyelid and enlarged cervical lymph nodes (figure 3). non - surgical treatment including chemotherapy and radiotherapy was discussed in detail with the patient and he eventually agreed to chemotherapy. the patient received cisplatinum 50 mg / m, adriamycin 50 mg / m, and cyclophosphamide 500 mg / m. computed tomography scan showing infiltration of tumor. a follow - up bone scan and ct scan of the patient clinically had progressive proptosis and worsening soft tissue thickening on the left side of his face. the patient was eventually referred to our service for consideration of enrollment in an experimental clinical trial. the patient was treated on several phase i experimental protocols, but eventually had persistent thrombocytopenia which precluded him from pursuing any additional therapy. the patient s disease started to cross the midline of the face and ac developed in his right eyelid as well. the right eye lid became quickly and progressively swollen causing his right eye to shut. unfortunately, the patient became incapacitated, as he was not able to see out of both eyes ; in essence the disease had rendered him blind. ac also was present on his lips and perioral area causing difficulty with eating and swallowing food and liquids. six years after his initial diagnosis, the patient entered hospice for supportive and palliative care. case reports have described transient responses to various chemotherapy agents such as, vincristine, bleomycin, cyclophosphamide and doxorubicin. described a patient with widely metastatic apocrine - gland carcinoma of the eyelid with an excellent response to systemic 5-fluorouracil chemotherapy. mezger j.,. described two patients with sweat - gland carcinoma who responded to combination chemotherapy with doxorubicin, cyclophosphamide, vincristine, and bleomycin. in one of these patients, a complete remission of two years duration was achieved ; the other patient had a partial remission of four months duration. the prognostic factors for sweat gland carcinoma are difficult to identify, again owing to the small number of reported cases. clinical trials of therapy, although difficult to conduct in a disease of low prevalence, provide additional options for patients and physicians. this case illustrates the detailed diagnostic evaluation and the need for high suspicion by the primary physicians to consider apocrine carcinoma of skin as a differential diagnosis for a skin lesion because of the high propensity of this tumor to locally metastasize and the lack of evidence - based clinical guidelines in literature for its management due to the rarity of the tumor. patients should be highly encouraged to undergo surgical resection, as this often is the only modality of therapy with curative intent. | apocrine carcinoma (ac) is a rare tumor with heterogeneous presentation. the disease has a highly morbid course and little is known about it. we present an otherwise healthy, 62-year - old asian male who originally presented with chronic swelling of his left eyelid associated with excessive tears and diminished vision was diagnosed with ac. ac is often challenging to diagnose, yet it is critical to do so as early diagnosis and treatment can maximize patient survival. |
the emergency department may offer a window of opportunity for women to discuss their experiences of intimate partner violence (ipv) with nurses and other health care providers. exposure to ipv impacts women 's health leading to acute and long - term physical and mental impairment [14 ]. lifetime prevalence of ipv reported in the emergency department ranged from 37% to as high as 50%. the emergency department is a health care setting where abused women often seek treatment and may disclose at higher rates than other health care settings [79 ]. due to the frequency with which abused women seek health care, many health care settings continue to adopt ipv - screening initiatives, and health care providers are encouraged to ask about violence as part of their routine care of women [4, 10, 11 ]. while abused women may seek care in the emergency department, many travel through the system without being recognized as exposed to violence. this is problematic in that nurses, who may be the first point of contact for abused women, may miss an important opportunity for assessment. this is compounded by the fact that emergency department nurses, like other health care providers, continue to face challenges in the detection and documentation of ipv [1315 ]. common barriers to discussing ipv cited by nurses and other health care providers included a lack of knowledge about ipv, a lack of time to respond to ipv - related issues and disclosures, a fear of offending patients, and a perception that violence is not a priority for their practice area [4, 16, 17 ]. a past negative communication experience with a nurse might prevent abused women from subsequently disclosing ipv when seeking emergency care [18, 19 ]. in a meta - synthesis of 25 qualitative studies. explored women 's perceptions of appropriate responses by health care providers to ipv disclosure. abused women seeking to disclose ipv to a health care provider valued nonjudgmental, compassionate, sensitive responses, and desired confidentiality. other primary studies found women exposed to ipv favoured similar provider characteristics including open, empathic communication and a nonthreatening clinical environment [18, 19, 21 ]. understanding the steps leading to ipv disclosure can improve nurses and other health care providers ' awareness and facilitate non - judgmental approaches to ipv detection and response. chang. recognized a gap in how health care providers understand and interpret abused women 's decisions and behaviours when seeking safety. very little information exists regarding how nurses and other health care providers engage in conversation with abused women and how they discuss safety issues related to ipv. in order to address this gap, chang. used an innovative mapping technique based on the transtheoretical model of change (ttm) to understand how women with a current or past history of ipv made changes that improved safety. maps were created for safety - seeking behaviours, and results revealed that women made changes gradually, and over long periods of time. a significant event often marked the moment when participants adopted a change that supported their increased safety. this event was identified by chang. as a turning point serving as a catalyst for change. these authors found that abused women took many steps towards seeking safety, and these steps were often influenced by other factors that were beyond their control. the transtheoretical model of change (ttm) has been used to explore the dynamic processes that individuals undertake when making behavioural changes through the following stages : precontemplation, contemplation, preparation, action, and maintenance. in precontemplation individuals precontemplators experience denial about their situations and respond defensively and with resistance to external pressure to change. when describing women exposed to ipv in this stage, zink. found that the women did not view their partners as abusive and described their relationships as normal. during contemplation, prochaska. described a stage where participants became aware of their problem and considered how to deal with that problem. however, participants were not ready to take steps to change the problem. when considering ipv, women in the contemplation stage acknowledged ipv as a problem but were not ready to leave their relationship. when we consider women exposed to ipv, making changes may be limited to what women themselves have control over, such as their decisions to disclose violence and adopt safety strategies. during this stage, women weighed the pros and cons of their situation and the potential actions that they could take to address their resolve perceived problems. while there were no set time periods for participants to move from stage to stage, authors stated that participants could remain in the precontemplation and/or the contemplation stages for years. during the preparation stage participants at this stage have not yet established criteria for effective action but had undertaken a series of small actions. chang. stated that abused women sometimes experienced a turning point event that significantly altered their thinking and attitudes regarding ipv making it impossible to return to the precontemplation stage. according to another author, women exposed to ipv defined the following significant life events that served as impetus for action : a violent encounter, financial independence, or concerns about children. these events, including those beyond the women 's control, led them to take definitive steps to resolve the problem at hand. chang. found that women created plans to change during the preparation stage. the most obvious behaviour changes occurred during the action stage where participants committed time and energy to modify their behaviours. participants in the maintenance stage continued changing their behaviour and attempted to prevent going backwards to a previous stage. when considering women exposed to ipv, brown argued that relapsing into a previously attempted stage may not be as likely to occur in the maintenance stage as it might in the action stage, since sustaining ongoing change women in the maintenance stage would include those who have left their abusive partners and have attempted to rebuild their lives without returning to their partners. there is a growing body of evidence regarding the use of the ttm applied to women who have experienced ipv [22, 2427 ]. early research that applied the ttm with ipv focused on women leaving their partners as the ultimate outcome of change. however, it was recognized that leaving the abuser could lead to reduced safety, diminishing resources and perpetuating ongoing harassment from the perpetrator [29, 30 ]. brown recommended that the health care provider refrains from using the outcome of leaving the relationship as an indicator of change. previous research explored the process of change among women who were preparing to leave abusive relationships or who left abusive relationships [22, 24, 26, 27, 29, 30 ]. using the ttm when the focus is on women choosing to leave an abusive relationship is problematic in that abused women may not have complete control over these complex circumstances. because of the complexity of abusive relationships where the perpetrator exerts control over the situation and many decisions, this impacts an abused woman 's autonomy to make changes. as a result, we consider the use of the ttm in relation to the decisions and changes that women themselves can control, despite remaining in an abusive relationship, such as decisions to seek health care, disclosure of ipv to a nurse, and undertaking other types of social support. little is known about the decisions and changes that abused women make when preparing to disclose ipv in emergency department settings. recognition of the change stage of abused woman can help nurses to plan appropriate support for ipv disclosure. this paper used an adapted form of the mapping methods proposed by chang. to understand how women move towards ipv disclosure in emergency departments. the ttm was used to interpret the sequence of events leading to ipv disclosure for a series of key participants. this paper examines the decision making steps that women undertake towards a change facilitating or inhibiting ipv disclosure. four change maps will be presented with a description of each turning point that was the catalyst for change. discussion will include how this mapping method can help nurses to gather information about a women 's readiness to disclose ipv so that appropriate assessment, and interventions can be offered. this paper is based on a secondary analysis of a sequential explanatory mixed methods study. the mixed methods study involved a quantitative subanalysis of data from a randomized, controlled trial (rct) followed by a grounded theory phase. the rct examined the effectiveness of routine screening for ipv in health care settings compared with usual care in reducing violence and improving life quality ; its methods are reported elsewhere. the grounded theory phase of the mixed methods study sought to explain the quantitative results and identify a core process related to ipv disclosure among a sample of women who participated in the trial. from the grounded theory study, women exposed to ipv undertook a process to minimize intrusion resulting from the disclosure of violence in the emergency department. the process had three phases : (a) deciding to seek care, (b) evaluating level of trust with the presenting health care providers, and (c) establishing personal readiness to disclose. abused women identified intrusion at various points including entry into a chaotic emergency department with long wait times and limited privacy, exposure to assessments requiring repeated descriptions of abuse to health care providers, feeling pressure to comply with evidence collection for potential legal proceedings, and/or involving other services such as police and/or child protection services. sampling for this mapping exercise occurred across the 19 participants in the grounded theory phase. while methods for sampling and data collection for the grounded theory phase of the mixed methods study are described elsewhere, theoretical sampling of participants involved the unit of analysis of ipv disclosure events. disclosure events were used in order to obtain conceptual density and a theory grounded in the data, despite a bounded sample of participants from the rct. this unit of analysis enabled constant comparison of findings in order to achieve theoretical saturation based on the incidents, events, or situations related to disclosure of ipv in urban emergency departments. the 19 women described 113 individual ipv disclosure events involving emergency department health care providers, social service professionals, police, family members, and friends. data for the grounded theory study was collected from 19 participants recruited from three emergency departments already enrolled in a rct in ontario, canada from may 2006 to december 2007. data collection involved face - to - face, in - depth, and semistructured interviews describing ipv disclosure events and lasted 6090 minutes. after an initial interview that focused on establishing trust and a description of abuse experiences, participants completed up to four repeat interviews in order to explore emerging themes and to saturate theoretical concepts. permission was obtained to review participant demographic data that was collected as part of the rct. nvivo 7.0 was used to organize data and complete coding of transcripts. in order to assess how participants moved through the ttm stages, an adapted form of chang. these authors briefly reported use of a grounded theory approach to coding to identify themes as they emerged from the data without use of a code book ; rather predetermined codes related to the ttm were created and applied to the transcripts. for this study, data were analyzed according to the stages of the ttm, including a second review of transcripts, after the development of the grounded theory that explained the processes used by women to disclose ipv to health care providers in urban emergency department settings. secondary analysis involved creating a coding structure for each participant 's data according to the ttm stages. during coding, behaviours, events, and potential facilitators and barriers to disclosure were coded for the ttm stages. data were reviewed for any potential factors related to the event that were beyond the participant 's control (e.g., partner losing a job) and these were coded with the corresponding event. once data were coded according to the ttm, each stage was examined closely for key behaviours and turning points that supported change towards ipv disclosure in an emergency department. because this sample of 19 participants described multiple disclosure events to various types of health care and social service providers, change maps described the emergency department disclosure that participants identified as most significant in facilitating change. after completion of the coding process, chang. 's methods were followed to map the stages of change per participant. these authors created a change map with an x - axis - depicting time and a y - axis - depicting stages of the ttm. for this analysis, time was not plotted due to the fact that movement through each stage was individual and may have occurred over multiple time periods. another adaptation to chang. 's method was to chronologically plot critical events or factors on the map. these events or factors influenced a participant 's movement from one stage to the next. unique to this analysis was the inclusion of a large arrow to identify and describe a turning point or significant life event provoking disclosure of ipv. this event represented an important change in a participant 's movement through the ttm stages toward action. also unique to this analysis was the inclusion of events when participants weighed options and evaluated their perceived risks before taking action. change maps were created and discussed with a master 's student with content expertise in ipv who served as a second coder for transcripts. both the rct and the grounded theory studies were approved by the mcmaster university / hamilton health sciences research ethics board, hamilton, ontario, canada and site - specific ethics boards. written informed consent was obtained prior to study enrolment. a formal safety protocol was followed and each participant received a resource support card with local area organizations (available from the authors). change maps revealed four participants in the precontemplation stage, six participants in the contemplation stage, three participants in the preparation stage, three participants in the action phase, and three participants in the maintenance stage. the majority of women did not move in a linear fashion through the stages of the ttm with the exception of three participants who moved from the precontemplation to the maintenance stage and disclosed ipv in the emergency department in a 12-month period. those participants in the maintenance stage would then go on to disclose ipv to other health and social services providers in the future. a summary of demographic characteristics is provided in table 1. among those participants in the precontemplation stage, ipv was not perceived as a problem that required immediate or short - term action. for this group of participants, emergency department care was sought for immediate injuries and concerns related to ipv and not disclosure. for the six participants in contemplation, they identified various sources of intrusion as potentially influencing their movement towards ipv disclosure. intrusion by nurses and other health care providers included judgmental responses for remaining in an abusive relationship or not following through on recommendations and an emphasis on efficient processing of clients through the emergency department. these participants also described intrusion from other services like the involvement of child - protective services and police. involvement of these services was seen to be long term and lead to potential apprehension of their children and subsequent punishment of their partners. for these participants, disclosing ipv in an emergency department setting required greater consideration and preparation. figures 1 and 2 show two participants who moved through the ttm using a sequential process of change. both carried out actions that they could control, such as a disclosure to an emergency department nurse. figure 1 shows a participant with the most linear movement through the ttm stages of change ending with a disclosure of ipv in the emergency department. this participant said that she had married her husband despite warnings from others that he had the potential to be verbally abusive. she sought care at the emergency department when she began to have frequent anxiety attacks, which she was able to relate to the ongoing verbal and emotional abuse from her husband. this participant did not identify her relationship as abusive and, upon realizing that it was, became embarrassed about her situation. the perceived risks associated with disclosure for this participant included experiencing judgment from health care providers, the fear of the violence getting worse, and fear that her husband would leave the marriage. physical abuse did not begin for this woman until after she became pregnant ; she sought care at the emergency department in order to protect her unborn child. for this participant, physical violence by her husband became more frequent as her first pregnancy developed. by the time the participant was seven months pregnant, a violent episode where she sustained physical injuries became her turning point to decide to seek care in the emergency department. while receiving treatment, the participant was able to identify a nurse whom she perceived as empathic and willing to listen to her story of abuse. for this participant, interaction with a non - judgmental and compassionate nurse was a facilitator to support her disclosure of ipv. another facilitator that supported ipv disclosure for this participant was the fear that if she did not discuss ipv, her newborn would be apprehended at birth by child protective services. this participant perceived disclosure to an emergency department nurse as a means of controlling when child protective services would be involved in her life. figure 2 depicts a participant who contemplated ipv disclosure and frequently sought emergency care. over the course of many visits to the same emergency department, this participant prepared for ipv disclosure by assessing the trustworthiness of health care providers. a health care provider could be trusted if s / he was non - judgmental maintained confidentiality when discussing sensitive issues, despite these participant 's frequent visits to the emergency department. the turning point event for this participant was severe physical injuries sustained from abuse from her partner. during her transport to the emergency department by ambulance, the participant considered the possibility of disclosure to a health care provider. one facilitating factor was her fear of death and survival through the night that became more important than the risks that she associated with disclosure. during this time this care received from the nurse served as a facilitator for the participant who then disclosed ipv. for two participants, disclosure of ipv occurred prior to being ready to disclose, and these participants were in the preparation stage of the ttm. the maps for these participants show a partial, nonlinear, and nonsequential movement through the stages of change. figure 3 shows a change map for a participant who felt unable to control many decisions related to seeking health care and disclosure of ipv. for this participant, she felt forced to disclose ipv to a health care provider when brought to the emergency department by emergency services. because the participant was unconscious at the time due to severe injuries, she struggled with the loss of control over her choices, such as when to seek health care. her loss of control was further compounded by her perception of intrusion from health care providers within the emergency department who were providing her care. for this participant, arose when health care providers repeatedly asked her whether or not her injuries were due to ipv. the participant described feeling forced to disclose ipv to emergency department health care providers prior to a sense of readiness. while it appears that she took action by disclosing ipv disclosing ipv, prior to being ready combined with perceived intrusion by health care providers, led to an avoidance of disclosure during future visits to the emergency department as a means of controlling her situation. barriers to disclosure of ipv were the lack of readiness, the fear that disclosure would lead to police involvement, and the fear that her partner would retaliate if he discovered the disclosure or if police charged him with assault. event of intrusion, this participant weighed her options and decided that the risks of retaliatory ipv from her partner outweighed her need to keep ipv under cover. action taken by this participant reflected a nonsequential movement through the ttm and occurred as a result of the influence of others despite her desire to keep abuse a secret. figure 4 shows a participant who also described a loss of control related to ipv disclosure in the emergency department. similar to the previous participant, in figure 4, this participant sought care in the emergency department on a regular basis for injuries sustained as a result of ipv. the turning point for this participant came when an emergency department health care provider approached her with a list of dates when she had sought care for her physical injuries. the health care provider then asked whether or not the participant sustained injuries from ipv. while she was still in the contemplation stages of the ttm, the participant disclosed ipv and felt forced to discuss her situation with the health care provider. barriers to disclosure for this participant were experiencing judgement from the health care provider for seeking emergency care on multiple occasions, feeling shame for requiring care as a result of abuse, and feeling embarrassment for remaining in an abusive relationship. for the participants in figures 3 and 4, neither felt a readiness to disclose ipv and felt forced to take the action of disclosing ipv prior to moving to the action stage of the ttm. chang. 's methods for mapping provided an innovative way to explore abused women 's movements through the stages of change. this mapping exercise gave a visual representation for the series of decisions and small actions toward ipv disclosure in the emergency department. similar to the findings of chang., the majority of change maps for participants lacked linearity and included the multiple interruptions over time by external factors. these authors found that some participants skipped some of the stages of the ttm due to factors beyond their control like pregnancy, illness, and substance use. likewise in our study, participants identified turning point events served to initiate action, for example, self - initiated ipv disclosure. some significant turning points that arose from this study were the fear of being killed by the perpetrator, fearing harm to an unborn baby or other children, needing emergency care for injuries related to violence, and feeling pressured to disclose ipv when asked by health care providers. this analysis provides new insights regarding participants who weighed options and considered their perceived risks of disclosing ipv with their perceived benefits. despite a presentation of what appears to be a simplistic diagram of action steps, this exercise demonstrated that ipv disclosure in the emergency department is a complex process influenced by factors within and beyond the participant 's control. for most of the women in this study, movement through the various stages of change took years and many visits to the emergency department that included treatment of injuries related to ipv. this exercise emphasized the role that clinicians can play in fostering client trust through communication and supporting a client 's readiness for ipv disclosure. nurses who encounter abused women can consider the processes that women undertake when deciding to disclose ipv in the emergency department setting. wong. stated that health care providers undervalued the crucial role they can play in the response to women exposed to ipv. among the participants of this study, ipv disclosure was found to be a positive experience when the nurse and other health care providers offered non - judgmental and empathic support. considering how abused women move through the stages of the ttm can help guide nurse 's conversations regarding ipv and work towards establishing the client 's trust. this mapping exercise could be used in future research to identify appropriate interventions that best fit with the ttm stage of change. several authors recommended patterning ipv - related intervention with the client 's stage of change [2426, 33 ]. for example, when a nurse might suspect that a client is exposed to ipv, she or he could include a discussion of the ttm and attempt to identify which stage of change is most applicable. these authors stated that a woman 's response to ipv - related questions indicated their stage within the ttm from denial of ipv (precontemplators) to describing strategies for how to deal with ipv (action). authors recommended that nurses and other health care providers conduct consciousness - raising whereby the clinician educates abused women on the risks associated with ipv and expresses concern about their client 's safety [25, 26, 33 ]. for the participants of this study, consciousness raising might have been helpful if it was provided over multiple occasions to the women who disclosed ipv. these women drew on any information or support from nurses and health care providers when they were actively preparing for disclosure. among the women in earlier stages such as precontemplation and contemplation, however, this intervention by nurses could have been interpreted as invasive and created further feelings of shame among women seeking treatment in the emergency department. this was especially of concern among those participants who perceived their interactions with health care providers as invasive. these participants continued to be in a place of denial and perceived judgement for their decision to remain in an abusive relationship. strategies to provide information about ipv in a noninvasive manner might assist participants concerned about further invasion from the health care provider. this mapping technique may help explain issues that challenge health care provider such as frequent and multiple visits to the emergency department by abused women. these authors argued that nurses and health care providers frequently misunderstand client behaviours and become frustrated when women seek emergency care on multiple occasions. women are often marginalized by the health care provider for the decisions they make in their relationships. this lack of understanding of the strategies that women use to mitigate the risks that they associate with ipv disclosure could serve as a barrier to women attempting to establish the nurse 's trustworthiness and, ultimately, their own internal readiness for ipv disclosure. this mapping activity can also support health care provider education by addressing the lack of education or skills barrier related to ipv frequently cited by participants [16, 17, 35, 36 ]. use of change maps illustrates how taking action towards ipv disclosure is a long process involving multiple visits to the emergency department. understanding this can help nurses to recognize the complexity of ipv disclosure, which is often a slow process towards change. awareness of the factors that facilitate and impede ipv disclosure may help ease judgments against a client for her decision not to disclose ipv. in the absence of evidence for effective interventions related to ipv disclosure, the research provided by authors on stage - based approaches related to ipv can help shift nurses and other health care providers attitudes to women exposed to ipv from one of judgment to one of neutrality. one limitation of this study is its reliance on one set of informants women exposed to ipv to describe events and circumstances related to ipv disclosure. it would have been useful to include perspectives from nurses and other health care providers. it is difficult to discern whether participants shared all events related to the disclosure process or may have had difficulty recalling their experiences related to ipv disclosure. future research could include women who had recently disclosed ipv within a specified time period, as opposed to participants who had disclosed over varied time periods. in conclusion, these findings suggest that few women followed a linear pattern using the transtheoretical model of change. the mapping technique can be a useful for emergency department nurses working with abused women to begin and guide conversations related to ipv. consideration of the complex process of change and conveying a willingness to discuss ipv may promote trust and engagement between client and nurse. | background. the transtheoretical model of change (ttm) was used as a framework to examine the steps that women took to disclose intimate partner violence (ipv) in urban emergency departments. methods. mapping methods portrayed the evolving nature of decisions that facilitated or inhibited disclosure. this paper is a secondary analysis of qualitative data from a mixed methods study that explored abused women 's decision making process about ipv disclosure. findings. change maps were created for 19 participants with movement from the precontemplation to the maintenance stages of the model. disclosure often occurred after a significant turning point event combined with a series of smaller events over a period of time. the significant life event often involved a weighing of options where participants considered the perceived risks against the potential benefits of disclosure. conclusions. abused women experienced intrusion from the chaotic nature of the emergency department. ipv disclosure was perceived as a positive experience when participants trusted the health care provider and felt control over their decisions to disclose ipv. practice implications. nurses can use these findings to gauge the readiness of women to disclose ipv in the emergency department setting. |
it is characterized by tubular crystalline deposits of calcium oxalate leading to acute and chronic tubular injury, interstitial fibrosis, and progressive renal insufficiency. a 54-year - old male was seen in our nephrology clinic for progressive increase in his serum creatinine from 1.38 to 3.66 mg / dl over 9 months. there was no history of fever, diarrhea, steatorrhea, urinary tract symptoms, renal stones, or use of nephrotoxic agents. his past medical history included hypertension for 15 years, type 2 diabetes for 11 years, obstructive sleep apnea, depression, and treated cellulitis. he had undergone a duodenal switch procedure for morbid obesity (body mass index > 50 kg / m) 20 months earlier. subsequently, he had lost more than 100 kg of body weight, and there was significant improvement in the control of blood pressure, sleep apnea, and blood sugar. his serum creatinine was 1.38 mg / dl and urinalysis was normal at the time of surgery. laboratory investigations showed hemoglobin of 9.9 g / dl, white cell count of 6.9 10/l, blood urea nitrogen of 51.82 mg / dl, and serum creatinine of 3.66 mg / dl. urinalysis showed 5 - 10 white cells / hpf and 1 - 2 white cell casts without any proteinuria or hematuria. ultrasound of kidneys showed normal sized kidneys with a few small bilateral calculi without any evidence of obstruction. the kidney biopsy [figures 1 and 2 ] demonstrated 13 glomeruli of which six were globally sclerosed. the tubular interstitial compartment showed foci of tubular damage with deposition of translucent crystals of different shapes which are predominantly intraluminal with few intracellular and focal interstitial distributions. under polarized light, the deposits appeared strongly birefringent forming fan - like, sheaf - like, or irregular shapes consistent with calcium oxalate crystals. the immunofluorescence was negative and electron microscopy did not show any electron dense deposits but did reveal tubular damage with intratubular crystal deposition. his 24-h urinary oxalate level was found to be significantly elevated at 98.7 mg / day (normal range upto 40 mg / day). large intraluminal translucent crystals of calcium oxalate, tubular epithelial degeneration (foamy cytoplasm, pyknosis, karyorrhexis, indistinct cell borders, dilated lumina), lymphocytic infiltration in the interstitium (h and e, 400) large intraluminal translucent crystals of calcium oxalate, tubular epithelial degeneration, multinucleated foreign body giant cell reaction (h and e, 400) a diagnosis of oxalate nephropathy secondary to enteric hyperoxaluria post - duodenal switch operation was made and he was started on low - oxalate, low - fat diet, with high - fluid intake (> 3 liters per day). in addition, he was prescribed calcium citrate 1000 mg tid with meals as an oxalate binder. he was also started on cholestyramine 4 g twice daily and repeat urine oxalate improved markedly to 63 mg / day and his serum creatinine stabilized. we report a case of oxalate nephropathy occurring in the second - year post - duodenal switch surgery for morbid obesity. estimates from the national center for health statistics show that the prevalence of obesity in the usa exceeds 30% in most age groups across both genders. presently, gastric banding, roux - en - y gastric bypass surgery (rygb), and duodenal switch operation are the commonly practiced bariatric surgeries. there is evidence for significant benefit in terms of improvement in hypertension control diabetes, dyslipidemia, urinary albumin excretion, markers of atherosclerosis, and progression of chronic kidney disease (ckd) after weight reduction surgeries.. with increasing numbers of rygb and duodenal switch operations being performed, the complication of oxalate nephropathy is coming to light. oxalate nephropathy is progressive in nature and has a poor prognosis. with rygb or duodenal switch surgery, the patient has an increased absorption of oxalates from colon leading to enteric hyperoxaluria. the increase in oxalate absorption and subsequent excretion in this setting is related to fat malabsorption leading to unavailability of free calcium for binding oxalate in gut, and unabsorbed bile salt - induced increased colonic permeability to small molecules, such as oxalate. in 2005, nelson. park. measured 24-h urinary collections in 45 patients after bariatric surgery over 2 years and reported that bariatric surgery was almost uniformly associated with increased urinary oxalate and calcium oxalate super saturation. other important potential factors contributing to nephrolithiasis in this population were decreased urinary volume and decreased urinary citrate. in a large group of 4,639 rygb patients, the incidence of nephrolithiasis was 7.7% compared with an incidence of 4.6% in an equally large control group of obese patients who had not undergone an operation. until now, only a few case reports of oxalate nephropathy have been reported after bariatric surgery. in a mayo clinic series of 60 cases of post - rygb, only two had oxalate nephropathy and both reached end - stage renal disease (esrd). nasr. have reported the largest series of oxalate nephropathy with 11 cases diagnosed post - rygb of which eight reached esrd. the diagnosis of oxalate nephropathy should be suspected in any patient who presents with sub - acute or chronic renal failure following bariatric surgery. a 24-h urine collection for oxalate excretion to look for hyperoxaluria and a kidney biopsy is needed for confirming the diagnosis of oxalate nephropathy. it is not uncommon to find other renal lesions such as hypertensive glomerulosclerosis, diabetic nephropathy, or obesity - associated focal segmental glomerulosclerosis concomitantly due to the co - morbidities of these patients. a low - fat diet is recommended to reduce the binding of calcium by free fatty acids. the use of calcium salts to bind oxalate is the mainstay of therapy, though there is little published on the efficacy of this approach. calcium citrate may be preferable to calcium carbonate as there is almost universally concomitant hypocitraturia. but the risk of increased aluminum absorption and worsening of bone disease should be kept in mind, especially if the patient has advanced ckd. cholestyramine may also be helpful as the presence of bile salts in the colon may increase colonic permeability to organic acids such as oxalate. though bariatric surgeries have significant benefits in terms of mortality and morbidity, it is important that the clinician be aware of post - procedure risk of developing secondary enteric hyperoxaluria, nephrolithiasis, and renal failure due to oxalate nephropathy. | obesity is a major public health issue all over the world. bariatric surgery is increasingly becoming popular as a surgical treatment for morbid obesity. nephrologists need to be aware of possible renal complications after bariatric surgery. we report a 54-year - old male patient who presented with progressive worsening of renal function following a duodenal switch procedure for morbid obesity, and he was found to have oxalate nephropathy on renal biopsy. |
a 7 year - old, 113 cm, 17 kg, female patient with tooth decay presented for general anesthesia for tooth conservation day surgery because outpatient treatment was not possible due to her lack of cooperation. her medical history showed that she had been delivered normally after 39 weeks of gestation, weighing 2.8 kg. at birth, seven months after birth, pediatric parent visits were made due to a general developmental delay, microcephaly, and sleep disorder. fourteen months after birth, brain mri (magnetic resonance imaging) was performed, which revealed no abnormalities. however, a chromosomal study showed a deficiency of chromosome 15 at q11.2-q13, and a fish (fluorescence in situ hybridization) test confirmed angelman syndrome (fig., spasms began to occur, which became severe when the sleep disorder happened frequently. at approximately age 4, general myoclonus epilepsy occurred. thereafter, she took valproic acid 125 mg, in divided into two doses two times per day, and experienced convulsion at 3 to 5 months intervals. an sms (social maturity scale) test, which was taken in the 30 month after birth, revealed severe intellectual retardation with a social age of 0.32. regarding motor development, she was equivalent to a 4 - 7 month old for the gross motor, 1 - 4 month old for the fine motor, and 1 - 2 months old for language development. the neurological test revealed that the child 's flexor in the arms and legs was hyper - tensed, her skeletal muscle was not fully developed, and she showed slight dystonic tremor. the morphological characteristics were microcephaly and hypoplasia of the maxillary bones. in the anteroom for day surgery, the child patient was uncooperative with the medical staff and would not leave her parent. the girl could not walk, and she was nestling in her parent 's arms, speaking incomprehensible words and making infelicitous laughs. the blood test before the operation revealed a hemoglobin level of 11.8 g / dl, which was slightly low.. in the anteroom for day surgery, an intravenous route was secured with the assistance of the surgical staff and parent. for the induction of general anesthesia, midazolam 2 mg instead of the ketamine commonly used in the hospital was administered with concern over seizure. however, it failed to sedate her and another 2 mg was administrated, which had no effects. a decision was made not to use different kinds of intravenous anesthetics because of the concern about the delay in awakening and restoration from anesthesia. the girl was carried into the operating room (or) in her parent 's arms. the vital signs immediately after entering the or revealed a blood pressure, pulse rate and oxygen saturation of 110/60 mmhg, at 110/min and 96%, respectively. sevoflurane and 100% oxygen were employed to induce anesthesia, and after administering rocuronium bromide 10 mg as a muscle relaxant, mask ventilation began and there was no difficulty in ventilation. after confirming full muscle relaxation, an orotracheal intubation was performed with a cuffed endotracheal tube (4.5 mm) without problems. expecting trouble in endotracheal intubation, oropharyngeal intubation was first performed and the operation proceeded while maintaining orotracheal intubation at the consent of the pediatric dentistry department. by regulating the oxygen to air ratio to set a fraction of inspired oxygen (fio2) at 0.5, controlled respiration was performed to maintain a partial carbon dioxide pressure in expiration of 30 - 35 mmhg while maintaining anesthesia with sevoflurane 3 vol%. during surgery, the blood pressure and pulse oximetry was stable at 100 - 110/60 - 70 mmhg and 99 - 100%, respectively. pyridostigmine 5 mg and glycopyrrolate 0.15 mg were then administrated to reverse muscle relaxant. before extubation, the train of four (tof) stimuli was measured to indicate 3 and the endotracheal tube was removed after confirming that the muscle function had been fully restored. the total length of time for tooth conservation surgery was 100 minutes, and the length of anesthesia was 125 minutes. in the postanesthetic recovery unit, the patient showed stable breathing and vital signs and her motion functions were checked after reaching consciousness. the next day 's follow - up phone call also confirmed her good general condition without significant complications. angelman syndrome (as) is a congenital disorder showing a variety of clinic manifestations due to a partial deficit on the paired chromosome 15. the prevalence of as is one in 10,000 - 40,000 of the population and its clinical characteristics are so diverse that a diagnosis of as rests on a combination of molecular genetic testing and/or cytogenetic analysis. 70% of as patients have the loss of the maternally contributed region of chromosome 15q11 - 13, while 15% of as have uniparental disomy coming from a paternal contribution. 60% of the paternal deletion in the chromosome region 15q11 - 13 may cause prader - willi syndrome (pws). the characteristic symptoms of pws can be differentiated from those of as by the clinical features, by hypotonicity and early obesity in infancy, mental retardation and hypogonadsm. genetic imprinting refers to the accentuation or activation of genes that can be expressed in a parent - of - origin - specific manner. for the remaining 20% of as cases, no genetic malformation is manifested but patients have a mutation of the ube3a gene and show fewer abnormalities in the electroencephalographic (eeg) findings and a smaller number of spasms. the clinic features of a genetic mutation and deficiency vary according to the gene expressions of rb3, which is critical in the genetic coding of the 3 subunit of the gaba - areceptor. many drugs acting on the central nervous system, such as anti - anxiety medication, sedative - hypnotics, general anesthetics, anti - seizure drugs, etc. are considered to acton the gaba receptor. a study on genetically manipulated mice of aminoacid mutated from the 3 subunit of the gaba receptor showed that reduced effects of propofol and etomidate. homanics. reported a meaningful decrease in benzodiazepine binding in genetically manipulated mouse models of angelman syndrome. in the present case, midazolam 4 mg was administered into the vein before surgery to reduce the patient 's anxiety, but she was not sedated. a change in the distribution of the receptors caused by isoflurane and partly by sevoflurane activates the outer structure of the synapse through osmotic changes in ions. such a polar change in neuronal cells not only restrains the activity of neuronal cells themselves but also reflect the state of the general anesthetics. therefore, it is reasonable to minimize or avoid administering an excessive dose of benzodiazepine to patients with this syndrome, and to refrain from using halogenated ethers as an inhalation anesthetic. from a theoretical viewpoint, intravenous anesthesia using a combination of propofol and fentanyl, which are not known to collide with the gaba system, will be safe. on the other hand, patients with as can show symptoms of separation anxiety due to their severe mental retardation. for child patients who show separation anxiety at general anesthesia for outpatient surgery, securing an intravenous route after admitting the patients into the operating room accompanied by their parents and sedating them with inhalation anesthetics is desirable for reducing the children 's anxiety. patients with this syndrome usually require general anesthesia for orthopedic surgery for the skeletal system dysfunction or even in a simple operation because they are uncooperative. as may not be detected at birth or during infancy, and is revealed mainly after the age of four, when the characteristic behaviors and signs appear. with several exceptions, table 1 shows the consensus criteria of the clinical features in as, enacted in 2005. patients with as do not have cardiovascular disorders or arrhythmia as common features but may have bradycardia due to hypertension of the vagus nerves. this phenomenon is noticed mainly during convulsive laughter, which can contribute to severe arrhythmia or ventricular asystole or fainting, resulted from an increase in the intrathoracic pressure and valsalva effect. the administration of atropine to treat the unexpected arrhythmia during surgery is not always effective. moreover, the immediate use of cardiac massage and epinephrine should be considered if asystole occurs. malformations of the skull and facial bones (microcephaly, mandibular bulging, etc.) found in patients with as can be a serious hindrance to tracheal intubation. however, the present case did not experience significant difficulty, and the literature review has not reported any difficulty in tracheal intubation. however, preparations should be made for any possible contingency when an unexpected malformation is confronted. many patients with as take medication for hyperactivity and epilepsy. to prevent perioperative epilepsy, it will be wise to keep taking anti - seizure drugs during the operation. however, it is unclear if all patients with as should take anti - seizure medication as preventive medicine. when choosing anesthetics, drugs that can cause seizure, such as ketamine or enflurane, should be avoided. peripheral muscular atrophy is another problem that needs to be considered when administrating anesthesia to patients with as. when it does occur, the sensitivity may increase, and a smaller amount of muscle relaxant than the usual dosage should be applied. monitoring the level of muscle relaxation is required to ensure the appropriateness in the degree of muscle relaxation during operation and during restoration from muscle relaxation after surgery. in the present case, the anesthesia was induced with inhalation anesthetics and maintained with a small dose of muscle relaxant, while there were no added muscle relaxants except those administered before the induction of anesthesia. tof (train of four) stimuli indicated a count of 3 before extubation after surgery. monitoring of the muscle relaxation of patients is necessary because of the possible risks of seizures and peripheral muscular atrophy. in particular, for outpatient surgery, extra precautions against accidents, such as falls due to muscular atrophy, should be taken after being discharged home. in addition, preparations should be made for emergencies, such as arrhythmia and ventricular asystole due to the hypertension of the vagus nerves. the difficulty in securing the respiratory tract in cases with malformations of the facial bones should be anticipated. in addition, proper attention should be paid to the choice of intravenous anesthetics and their correct dose in an abnormal case of an impairment of the gaba receptors. | angelman syndrome is characterized by a partial deficit of paired autosomal chromosome 15, which contains a subunit of the gaba (gamma - amino butyric acid) receptor. many drugs that act on the cns (central nerve system) during anesthesia are believed to exert their effects via the gaba receptors. we describe the anesthesia of a 7 year - old female patient with angelman syndrome who underwent surgery for dental caries. the basic factors that needed to be considered when administering anesthesia to this patient were epilepsy, significant dominance of the vagal tone, craniofacial abnormalities and peripheral muscular atrophy. inhalational anesthetics (sevoflurane) were employed for this patient. the patient had an uneventful peri - operative period and was discharged home on the same day of the operation. |
in addition, vascular regeneration and repair are essential for the survival of blood vessels. there are still uncharacterized and less characterized cell types in vascular adventitia, which include vascular stem / progenitor cells [110 ] and adventitial neuronal somata (annies). the vascular adventitia is a complicated tissue, which is found to be the most active layer in terms of cell turnover. nerva vasorum. using fluorescence confocal microscopy (fcm) to visualize vascular wall 3d organization of different cellular and extracellular elements of the intact artery with minimal 3d distortion [11, 13 ], we recently demonstrated annies coexpressing neural cell adhesion molecule (ncam) and calcitonin gene - related peptide (cgrp) in the adult rat mesenteric branch artery (mba). the present study was designed to further characterize annies in adult rat mba as cells with axonal and neurite growth markers, such as growth - associated protein-43 (gap-43) and palladin, and to determine whether they express the calcium sensing receptor (casr). recently, casr mrna and protein expression has been demonstrated in rat whole mba and other vascular tissue extracts, also shown in vascular smooth muscle cells in culutre [15, 16 ]. none of these studies show the specific cell(s) in the artery in situ expressing the casr. we demonstrate here that nucleated annies cells together with nerve processes clearly express palladin, casr, and coexpress gap-43 protein in the whole mount mba by immunofluorescent staining followed by laser confocal analysis. all procedures using laboratory animals were reviewed and approved by the institutional animal care and use committee of north carolina central university. male wistar rats, 1012 weeks of age, were obtained from harlan sprague dawley (indianapolis, usa). all animals were continually monitored, and upon arrival, they were maintained in colony rooms with fixed light : dark cycles and constant temperature and humidity and provided with purina rodent chow (harlan teklad, madison, wis, usa) and water ad libitum. mesenteric arteries were dissected from rats (n = 10) as previously described. in brief, rats were deeply anesthetized with 2% isoflurane and then sacrificed by open chest cardiac puncture. the small intestine and all vessels feeding it were removed in block and placed in cold physiological salt solution (pss). branch i and ii arteries were carefully dissected from the surrounding fat and mesenterium, taking care to leave a portion of the omental membrane attached to the vessel. a 12 m - diameter stainless steel wire was inserted into the lumen to remove blood and to serve as a handle for moving the vessel segment between solutions. vessels of mba were fixed in buffered formalin for 20 min and washed three times in tbs (tris - buffered saline). the vessels were kept in blocking solution containing 8% bsa in tbs and incubated with primary antibody such as polyclonal anti - gap-43, anti - casr (molecular probes), anti - palladin (gift from dr. otey, unc - chapel hill) overnight at 4c. for dual immunofluorescence staining anti - cgrp (phoenix pharmaceuticals, calif), and anti - gap-43 (molecular probes) were incubated for 2 h at room temperature (rt). after incubation, the vessels were washed thrice in tbs and incubated with appropriate secondary antibody tagged with alexa fluor 647 alone, and with 488 in case of co - staining for 1 h at rt. after washing thrice in tbs, vessels were incubated with the nuclear stain sytox (petticoat junction, or) to identify the nuclei of annies. vessels were mounted on glass slides in a glycerol - based antifade medium (molecular probes) after washing. segments were viewed with a zeiss lsm 510 confocal microscope (zeiss instruments) with 100x, 40x, and 20x oil immersion objectives. we considered the number of cgrp staining cells as 100% of annies, and calculated the percentage of annies expressing the other markers (gap-43, casr and palladin) in comparison to the cgrp expressing cells. protein was extracted from minced mba (n = 5) by homogenizing in a ground - glass homogenizer (mba) in buffer containing 10 mm tris, ph 7.5, 0.25 m sucrose, 3 mm mgcl2 containing 1% (v / v) triton x-100, dithiothreitol (1 mm), pe - fabloc (1 mm), leupeptin (10 m), bestatin (130 m), pepstatin (1 m), and calpain inhibitor ii (10 g / ml). the homogenate was then centrifuged at 16,000 g for 10 min and the pellet was used for ncam, gap-43 and palladin. the pellet was dissolved in buffer containing 10 mm tris, ph 7.5, and 1% triton x-100, size separated using 8% sds - page, and electroblotted onto nitrocellulose membrane (bio - rad laboratories, ca) as described., calif) and visualized using an hrp - conjugated secondary antibody, and the chemiluminescence method (amersham pharmacia biotech, nj). we used the whole mounts of the adult rat mba and immunofluorescence confocal microscopy imaging to further characterize annies in arterial adventitia. the use of whole - mount mba from rats enabled us to have an accurate reconstruction of the cellular and nerve interrelationships and innervation patterns of perivascular adventia and vasa nervorum within the mba. this also facilitates the ability to study the expression pattern of the neurochemical markers in situ, without the need to cut them as with conventional histology. furthermore, this approach allows us to localize and visualize the morphology / phenotype and quantify these cells (annies) and nerve structures in situ coexpressing vasodilator trophic factor cgrp and ncam, and axonal growth markers gap-43 (figure 3) as well as casr (figure 1). casr is shown to play significant role in blood pressure regulation by releasing an unknown vasodilator. more recently, weston. reported that this vasodilator is still unidentified. we hypothesize that the vasodilator released by casr, which is still unidentified, might be the potent vasodilator neuropeptide, cgrp. our present finding demonstrates that 94 6% (n = 3) annies cell bodies express the casr (figure 1), compared with the annies identified by the expression of cgrp as previously demonstrated. the casr is shown to regulate the production of cgrp that is involved in the regulation of the release of the neurotransmitter in the synaptic space. our laboratory has demonstrated that the casr mediates ca2 + induced relaxation of isolated mesenteric arteries via an unknown vasodilator substance, which is independent of endothelium and no. these previous findings support our hypothesis that this putative vasodilator released by the casr might be the cgrp expressed in annies and perivascular nerve fibers. we demonstrate here that nucleated annies cells and the nerve processes strongly express the casr. it is shown to locate in the growth cones of growing neurites, where it interacts with f - actin associated adhesion molecule and/or extracellular matrix complexes to promote neurite extension. in addition, it has been shown that the phosphorylated gap-43 stabilizes long actin filaments and has the ability to directly influence the structure of the actin cytoskeleton response to extracellular signals. similarly, palladin has been shown to express in the growth cone and colocalize with focal adhesion and respond to vascular and dermal injury. confocal analysis of the whole mount mba in our experiment showed that gap-43 is strongly distributed in 37 4% of the perivascular nerve fibers (figure 2, n = 3), and coexpressing cgrp (figure 3), also identified by the expression of casr (figure 1). palladin is present in both smc and annies in the rat mba (figure 1). palladin expression is apparent in a mixed population of fibroblasts and in cells with nerve processes, annies (figure 1) that were shown to coexpress cgrp and ncam. the casr and palladin were present in annies about 94 6% and 80 10% (n strong immunofluorescence for ncam, and axonal growth markers such as gap-43 as reported in this paper, revealed the presence of many neuronal cell bodies within the vasa nervorum of rat mba. in addition, the presence of gap-43 in annies indicates that annies shows features of sensory neurons of the drg, undergoing responses to stress / injury, given that the expression of gap-43 in drg cells is increased in response to injury [27, 28 ]. in addition, cgrp induces schwann cell proliferation, and thus thought to be involved in peripheral nerve injury and repair. immunoblots from the rat mba also confirmed the presence of gap-43 (figure 4) and palladin as two isoforms of 9092 and 140 kd (n = 3). this protein pattern is different from other adult tissues such as brain that expresses three isoforms (9092, 140, and 200 kd) or smc where only one isoform (9092 kda) is expressed. casr protein expression by western blot in the protein extract of the whole mesenteric artery was reported. we previously demonstrated beta - cgrp expression in rat mba by rt - pcr, cloning, and sequence analysis. cells that are not with nerve fibers, probably fibroblasts, were also stained for palladin as it has been reported by other investigators. there is no nerve like structures around some of the fibroblast like cells that express palladin. in addition, ncam, cgrp, and gap-43 are expressed in annies, but these markers are not shown to express in the other adventitial fibroblasts, smooth muscle, and endothelial cells. this is the first report that cells in the peripheral vasculature with a neuronal phenotype express markers of active neurite growth. the presence of cgrp - containing neural cells in the vascular adventitia may participate in response to injury and vasodilator mechanisms as part of a perivascular sensory neural network. annies cell morphology with nerve fibers and expression of neural and neurite growth markers reveal that these cells are distinct from the other known cells in blood vessel. the additional finding that the casr is associated with annies suggests that these cells may participate in the regulation of myogenic tone. | a novel perivascular adventitial cell termed, adventitial neuronal somata (annies) expressing the neural cell adhesion molecule (ncam) and the vasodilator neuropeptide, calcitonin gene - related peptide (cgrp), exists in the adult rat mesenteric branch artery (mba) in situ. in addition, we have previously shown that annies coexpress cgrp and ncam. we now show that annies express the neurite growth marker, growth associated protein-43(gap-43), palladin, and the calcium sensing receptor (casr), that senses changes in extracellular ca(2 +) and participates in vasodilator mechanisms. thus, a previously characterized vasodilator, calcium sensing autocrine / paracrine system, exists in the perivascular adventitia associated with neural - vascular interface. images of the whole mount mba segments were analyzed under scanning confocal microscopy. confocal analysis showed that the gap-43, casr, and palladin were present in annies about 37 4%, 94 6%, and 80 10% respectively, comparable to cgrp (100%). immunoblots from mba confirmed the presence of gap-43 (48 kd), ncam (120 and 140 kd), and palladin (9092 and 140 kd). in summary, cgrp, and ncam - containing neural cells in the perivascular adventitia also express palladin and casr, and coexpress gap-43 which may participate in response to stress / injury and vasodilator mechanisms as part of a perivascular sensory neural network. |
as one of the most common intracranial tumors in humans, pituitary adenoma is the third most common primary brain tumor after glioma and meningioma, accounting for about 15~20% of all primary intracranial tumors. the average incidence of pituitary adenoma is about 7.5~10 per 100 000 population, but has rapidly increased in recent years. many pituitary tumors are identified by mri or ct when diagnosing nasopharyngeal disease, brain trauma, or other head injury, with an incidence of over 20%. although it is a benign tumor, some pituitary adenomas showed invasive growth with a malignant tendency, invading peripheral tissues, including bone, dura matter, suprasellar, parasellar, and even cavernous sinus or / and sphenoid sinus, entrenching blood vessels and nerves. the radical treatment of ipa is extremely difficult because it is hard to completely remove during surgery. even with post - operative radio-/chemo - therapy, the recurrence rate is still as high as 21~86%. basic research has been performed to explain the molecular mechanism governing the occurrence and progression of ipa from genetic or protein levels, in an attempt to obtain early diagnosis, prognostic evaluation, and guided treatment. microrna (mir) is a family of endogenous, non - coding, single - stranded rna 21~23 nucleotides in length. it can regulate gene expression at the post - transcriptional level via inhibiting translation or degrading target mrna. mir has been found to affect a series of biological processes, including cell proliferation, apoptosis, differentiation, migration, and tumor malignant transformation. the abnormal expression and function of mir is closely correlated with the occurrence, progression, recurrence, and malignant transformation of ipa. some scholars used high - throughput microarray technique to detect differential expression of mir across invasive and non - invasive pituitary adenoma. it has been confirmed that this differential expression of mir is closely correlated with invasive growth of pituitary adenoma. mir-26a has been demonstrated to be highly expressed in pituitary adenoma, suggesting its possible involvement in tumor occurrence. pleomorphic adenoma gene 1 (plag1) is a definitive target gene of mir-26a, and is involved in multiple biological effects in regulating cell proliferation, induction of cell apoptosis, and cell cycle arrest. under physiological conditions, plag1 is abundantly expressed in pituitary tissues, but is significantly downregulated in pituitary adenoma. however, the abnormal expression or function of mir-26a and plag1 related with occurrence of ipa is still unknown. this study aimed to investigate the relationship of pituitary tumor invasion with mir-26a and plag1. rna extraction reagent trizol was purchased from invitrogen (usa). reverse transcription and fluorescent quantitative pcr kit were purchased from takara (china). primers for reverse transcription of mir-26a and pcr were synthesized by ruibo bio (china). a total of 70 pituitary adenoma patients who received treatment in yantaishan hospital from december 2009 to july 2013 were recruited. there were 50 males and 20 females, with an age range of 2367 years (average age, 46.8 years). there were 22 macroadenomas (tumor size larger than 1 cm) and 48 microadenomas (smaller than 1 cm) cases. in pathological subtyping, there were 14 cases of acth adenomas (5 cases of invasion of sphenoid sinus, 6 cases of invasion of the cavernous sinus, 3 cases of invasion of the hypothalamus, 3 cases of 3-cm huge adenoma ; acth of blood > 46 ng / ml, average 156.41 + 45.65 ng / ml ; ufc/24 h > 100 g, average 387.5195.36 g), 16 cases of prolactin adenomas (7 cases of invasion of sphenoid sinus, 4 cases of invasion of the cavernous sinus, 5 cases of invasion of the hypothalamus ; 4 cases of 3-cm huge adenomas ; prl of serum > 200 ng / ml, average 436.8866.38 ng / ml), 15 cases of gh adenoma (6 cases of invasion of sphenoid sinus, 4 cases of invasion of cavernous sinus, 5 cases of invasion of the hypothalamus ; 5 cases of 1 g / l, average 4.520.58 g / l) and 25 cases of non - functional adenoma (pituitary tumor was found in sella by ct and mri, no other abnormal increase of pituitary hormone and clinical manifestations were not found except for prl ; serum prolactin levels 3-cm huge adenoma ; acth of blood > 46 ng / ml, average 156.41 + 45.65 ng / ml ; ufc/24 h > 100 g, average 387.5195.36 g), 16 cases of prolactin adenomas (7 cases of invasion of sphenoid sinus, 4 cases of invasion of the cavernous sinus, 5 cases of invasion of the hypothalamus ; 4 cases of 3-cm huge adenomas ; prl of serum > 200 ng / ml, average 436.8866.38 ng / ml), 15 cases of gh adenoma (6 cases of invasion of sphenoid sinus, 4 cases of invasion of cavernous sinus, 5 cases of invasion of the hypothalamus ; 5 cases of 1 g / l, average 4.520.58 g / l) and 25 cases of non - functional adenoma (pituitary tumor was found in sella by ct and mri, no other abnormal increase of pituitary hormone and clinical manifestations were not found except for prl ; serum prolactin levels 0.05 in all cases, table 1). using hardy classification as the criterion standard, we divided pituitary adenomas into invasive and non - invasive types. by constructing an roc, we calculated the classification accuracy of mir-26a / plag1 in differentiating invasive from non - invasive pituitary adenomas. the results showed certain differential diagnostic values of those 2 genes, as mir-26a had auc values of 0.889 for differential diagnosis between invasive and non - invasive pituitary adenoma, higher than that of plag1 (auc=0.818, figure 2). those patients with mir-26a high - expression had a significantly sharper survival curve than those with lower mir-26a expressions. in contrast, plag1 low - expression patients had a significantly sharper survival curve than those with higher plag1 expression (figure 3a, 3b). log - rank test results showed significantly lower survival rate of mir-26a high - expression patients than those with lower mir-26a expression (=7.393, p=0.007), while patients with lower plag1 expression had significantly lower survival rates than those with higher plag1 expression (=9.475, p=0.002). for patients with both mir-26a high - expression and plag1 low - expression, the prognosis was remarkably worse than in other patients (=11.400, p0.05 in all cases, table 1). using hardy classification as the criterion standard, we divided pituitary adenomas into invasive and non - invasive types. by constructing an roc, we calculated the classification accuracy of mir-26a / plag1 in differentiating invasive from non - invasive pituitary adenomas. the results showed certain differential diagnostic values of those 2 genes, as mir-26a had auc values of 0.889 for differential diagnosis between invasive and non - invasive pituitary adenoma, higher than that of plag1 (auc=0.818, figure 2). those patients with mir-26a high - expression had a significantly sharper survival curve than those with lower mir-26a expressions. in contrast, plag1 low - expression patients had a significantly sharper survival curve than those with higher plag1 expression (figure 3a, 3b). log - rank test results showed significantly lower survival rate of mir-26a high - expression patients than those with lower mir-26a expression (=7.393, p=0.007), while patients with lower plag1 expression had significantly lower survival rates than those with higher plag1 expression (=9.475, p=0.002). for patients with both mir-26a high - expression and plag1 low - expression, the prognosis was remarkably worse than in other patients (=11.400, p<0.001, figure 3c). we performed a cox regression analysis including age, sex, tumor size, invasiveness, adenoma type, mir-26a expression level, and plag1 expression level. using the maximal likelihood estimation biased forward selection method, we designated tumor invasiveness, mir-26a expression level, and plag1 expression level as independent risk factors affecting the survival of pituitary adenoma patients (table 2). invasiveness increased the death risk of pituitary adenoma patients by 0.899-fold (p=0.009). mir-26a high - expression increased the death risk by 1.833-fold compared to that in low - expression patients (p=0.022). on the contrary, elevated plag1 expression protected patients, reducing death risk by 39.7% (p=0.018). pituitary tumors are monoclonal tumors originating from residual epithelial cells of anterior / posterior pituitary and cranial - pharyngeal tissues, and account for about 10~15% of all intracranial tumors. clinically, however, about one - third of all pituitary tumors showed invasive growth, which is a biological behavioral of malignant tumors. such pituitary adenomas often show aggressive growth toward peripheral tissues / nerves, and thus are termed invasive pituitary tumors. invasive pituitary tumors have rapid progression, are difficult to completely removal during surgery, and have higher short - term recurrence rate after surgery, making clinical treatment a major challenge. the invasive growth of pituitary tumor is one important factor causing the recurrence of disease, further affecting clinical treatment efficacy and prognosis. recent studies have focused on the mechanism directing pituitary tumor proliferation, activation of oncogenes, and inactivation of tumor suppression genes, but the biological mechanism affecting tumor invasion / migration is still not fully understood. for instance, ccnd1 gene, a proto - oncogene, plays a role in pituitary tumorigenesis and invasiveness and its polymorphism in patients with different types of sporadic pituitary adenomas were determined. hypoxia can increase the expression of ddr1, a newly discovered kind of tyrosine kinase receptor on the cell surface, which in turn promotes pituitary adenoma cell proliferation and invasion. in particular, a recent finding showed that the expression of cold - inducible rna - binding protein (cirp) in pituitary adenomas is closely related with tumor proliferation and invasion, and its significantly elevated expression level indicates post - operative recurrence. therefore, understanding the invasion / migration mechanism and identifying the specific molecular marker for acquiring invasion / migration property are of critical importance for early diagnosis of pituitary tumors, broadening clinical treatment strategy, improving treatment efficacy, and guiding individualized treatment. with the advancement of molecular biology, the pathogenesis mechanism of ipa has been illustrated from the molecular level by some scholars. many signal molecules have been discovered during the modulation of cell proliferation, cycle, apoptosis, and differentiation, especially the critical role during tumor cell occurrence and invasion / migration, thus providing new evidence depicting the tumor invasion mechanism and advancing targeted treatment. microrna has been found to participate in occurrence, progression, invasion, and metastasis of pituitary adenoma via degrading target gene mrna or inhibiting their translation. some researchers utilized high - throughput microarray to reveal differential mir expressions between invasive / non - invasive pituitary adenoma. moreover, such differential expression of mir has been found to be closely correlated with invasive growth of pituitary adenomas. bottoni. utilized microarray analysis to screen the differential expression of mir between pituitary adenoma and normal pituitary tissues, and found the overexpression of mir-26a in pituitary adenoma, indicating its possible involvement in occurrence of pituitary adenoma. pleomorphic adenoma gene 1 (plag1) is located in human chromosome 8q12, with 7313bp full - length cdna. plag1 encodes 1 nuclear protein, which belongs to the zinc - finger protein family. with transcription factor activity a study has confirmed plag1 as a target gene for mir-26a, which regulates plag1 gene expression. under physiological conditions, plag1 is abundantly expressed in pituitary tissues, but is significantly downregulated in pituitary adenoma. the correlation between mir-26a / plag1 expression or function abnormality and the occurrence of pituitary adenoma is still unknown, as its relationship with the invasiveness of pituitary adenoma. the results of the present study show that, compared to normal pituitary tissues, pituitary adenoma tissues have significantly elevated mir-26a expression, indicating its potential involvement with pituitary adenoma occurrence. gentilin. found significantly elevated mir-26a expression in the acth - type pituitary adenoma cell line att20/d16v - f2. such upregulated mir-26a directly suppressed the expression of prkcd (protein kinase c), and facilitated the expression of cell cycle modulatory protein cyclin e and cyclin a, thus shortening the g1 phase and accelerating the cell cycle, indicating the facilitating role of mir-26a in pituitary adenoma, consistent with our observations. they also revealed more abundantly expressed mir-26a in ipa tissues compared to non - ipa tissues, suggesting the correlation between mir-26a and invasiveness of pituitary adenoma, in addition to tumor occurrence. the study revealed lower expression level of plag1 in pituitary adenoma tissues compared to that in normal pituitary tissues, especially in ipa tissues, suggesting the correlation of plag1 low - expression in occurrence and invasiveness of pituitary adenoma. however, no statistical significance was found in the proportion of high and low expressions of mir-26a and plag1 within different functional types of adenomas. found the physiological expression of plag1 protein in pituitary tissues and several other brain regions. ttt / gf significantly enhanced cell proliferation ability, suggesting the role of plag1 in anti - pituitary tumor proliferation. moreover, plag1 functions as a tumor suppressor gene in pituitary adenoma via facilitating cell apoptosis, inducing g1 phase arrest. ki-67 is a critical marker for differential evaluation of mitotic index between non - invasive and invasive pituitary adenoma, and is also an important marker determining the invasiveness of pituitary adenoma. thapar. found significantly higher mitotic index of ipa cells than those in non - invasive pituitary adenoma, suggesting that more active mitosis and uncontrolled tumor cell growth are critical factors for acquiring invasiveness by pituitary adenoma. therefore, the study showed that elevated mir-26a expression can affect the invasiveness of pituitary adenoma via targeted inhibition on plag1 expression, and antagonizing the tumor suppression effect of plag1 against pituitary adenoma cells. moreover, they analyzed the correlation between mir-26a / plag1 expression and clinical features of patients, and found the relationship between expression levels and tumor invasiveness. the study found higher diagnostic values of mir-26a and plag1 in differentiating invasive and non - invasive pituitary adenoma, indicating that the utilization of mir-26a and plag1 expression levels could effectively differentiate and evaluate the invasiveness of pituitary adenoma. compared to classical pre - operative imaging examination, endoscopy during the surgery, and post - operative pathological examination, the early clarification of tumor invasiveness by measuring mir-26a and plag1 expression levels is critical importance for early diagnosis and treatment of disease. the study found that mir-26a and plag1 expression levels are independent risk factors governing patient prognosis, and significantly affect patient s survival and prognosis. in summary, mir-26a plays a critical role during the occurrence and progression of pituitary adenoma, and may facilitate tumor occurrence and the acquisition of invasiveness, probably via inhibiting plag1 expression. our study provides new concepts for illustrating the mechanism of the invasiveness of pituitary adenoma, and provides novel methods and approaches for biological therapy against pituitary adenoma, justifying further exploration. | backgroundalthough pituitary adenoma is a malignant tumor, it can present as invasive growth in some cases. microrna (mir)-26a has been found to be abnormally highly expressed in pituitary adenoma, indicating possible involvement in pathogenesis. as a known target gene of mir-26a, plag1 has abnormally low expression in pituitary adenoma. the correlation between mir-26a or plag1 expressional abnormality and occurrence of pituitary adenoma is still unknown, as is its association with invasiveness of pituitary adenoma.material/methodspituitary adenoma tissues, including both invasive and non - invasive subtypes, were collected from our neurosurgery department, in parallel with normal pituitary tissues from postmortem autopsy. qrt - pcr was used to detect mrna expression of mir-26a and plag1, while western blotting was used to test plag1 protein expression. the correlation between mir-26a and plag1, and with pathological features, were analyzed. roc analysis revealed the utility of mir-26a and plag1 in differential diagnosis of invasive / non - invasive pituitary tumors and in analyzing their effects on patient prognosis.resultsmir-26a was remarkably upregulated in pituitary tumors, while plag1 was downregulated, especially in invasive pituitary tumors. mir-26a and plag1 had higher diagnostic values for differentiating between invasive and non - invasive pituitary tumors (auc=0.889 and 0.818, respectively). those patients with mir-26 overexpression and plag1 downregulation had unfavorable prognosis. mir-26 and plag1 are independent factors affecting patient diagnosis.conclusionsmir-26a can facilitate occurrence of pituitary tumor and invasiveness, probably via inhibiting plag1 expression. |
northern norway covers half of norway s land area and constitutes about two thirds of the size of the uk. it has a scattered population of about 470,000 inhabitants and the main industry is fishery. there are 88 municipalities in the region and almost half (42 municipalities) of them have less than 2,000 inhabitants. the significant distances between the populated areas have been a constant challenge to the health care service in terms of costs and logistics. in 2008, the northern norway regional health authority (nnrha) spent norwegian krone (nkr) 616 million (70 million) on patient transportation and nkr 943 million (106 million) on ambulance services (air, sea and land). the ambulance services accounted for 8.2% of the total budget of the nnrha in 2008 and this service experienced faster growth in terms of resources consumed than any of the other sectors. aiming to improve the ambulance service in norway, the national authorities introduced in 1996 the certificate of competence in prehospital care named fagbrev. the education consists of 2 years in college followed by 2 years of practice at a hospital ambulance service and finally the candidates have to pass an exam. persons who have been working in the ambulance services for at least 5 years may follow a fast track programme of 1 year and then head for the exam. in general one - man firms having contracts with any of the three county councils (finnmark, troms, nordland). furthermore, the ownership of the ambulances was taken over by the nnrha in 2007 and it has since been administered by the four hospital trusts (finnmark hospital trust, university hospital of north norway trust, nordland hospital trust, helgeland hospital trust). several crew members have been offered scholarships to get the certificate of competence (fagbrev). ecgs can be communicated digitally from the ambulances to the hospitals and prehospital thrombolytic therapy can be administered by the crew when myocardial infarction has been diagnosed. furthermore, the personnel have participated in continuous internal educational programmes and old ambulances have been exchanged for new ones. the hospital trusts have laid the groundwork for a modern coordination and location system for the entire ambulance fleet by installing a global positioning system (gps) in all cars. consequently, the lower number of clinics has increased the distance to travel. against this background, northern norway has a subarctic climate that may offer several challenges especially during winter time with cold weather conditions, seasonable darkness and a lot of snow. despite this the population expects a service of equal quality as provided in the southern and more populated regions. in this study, we focused on the total ambulance fleet service in northern norway and focused on location, activity, crew and level of competence in terms of education. air and boat ambulances were excluded from the survey. a geographic overview of northern norway and its three counties is shown in fig. 1. in april 2009, the data on activity performed by the ambulance fleet in northern norway was retrospectively analysed focusing on the 5-year time period from 1 january 2004 until 31 december 2008. the following data on ambulances, crew members and each location were collected : fig. 1map showing the three counties of northern norway (nordland, troms and finnmark) and the significant land area they coverdata on each operative ambulance (based on its i d) was noted according to location, trust owner, whether it was in use or in reserve and its daily operative hours.data on crew members were registered in terms of numbers at each location, their state of readiness (five levels : from at home to in active service at the station 24 h a day), manning and level of competence in terms of education (certificate of competence in prehospital care each location we registered the annual number of tasks performed, kilometres driven and running expenses. the number of inhabitants in the area served according to statistics norway (www.ssb.no) and the distance to the nearest somatic hospital were also noted. map showing the three counties of northern norway (nordland, troms and finnmark) and the significant land area they cover data on each operative ambulance (based on its i d) was noted according to location, trust owner, whether it was in use or in reserve and its daily operative hours. data on crew members were registered in terms of numbers at each location, their state of readiness (five levels : from at home to in active service at the station 24 h a day), manning and level of competence in terms of education (certificate of competence in prehospital care the number of inhabitants in the area served according to statistics norway (www.ssb.no) and the distance to the nearest somatic hospital were also noted. descriptive statistics was used. the statistical package for the social sciences (spss) version 16.0 was employed for statistical calculations. cases with an unknown value for a particular variable were excluded from analysis involving that variable. all p values are two tailed and considered statistically significant when p < 0.05. costs were calculated in nkr and converted into at a rate of 1 = nkr 8.8600 as of 24 july 2009 according to the national bank (norges bank) (www.norges-bank.no). descriptive statistics was used. the statistical package for the social sciences (spss) version 16.0 was employed for statistical calculations. cases with an unknown value for a particular variable were excluded from analysis involving that variable. all p values are two tailed and considered statistically significant when p < 0.05. costs were calculated in nkr and converted into at a rate of 1 = nkr 8.8600 as of 24 july 2009 according to the national bank (norges bank) (www.norges-bank.no). there were a total of 124 ambulance units and 6 reserve units distributed in 84 locations ; 109 units (88%) were manned day and night and the figures were constant during the study period. the numbers of full - time posts were university hospital trust 255, nordland hospital trust 156, helgeland hospital trust 90 and finnmark hospital trust 151, respectively. during the 5-year study period, the total number of tasks performed in the region rose by 13% from 63,109 to 71,463 tasks. the mean number per ambulance in 2008 was 576 tasks. whereas a slightly falling trend was seen in nordland county (nordland hospital trust and helgeland hospital trust) following the takeover by the nnrha table 1activity measured in number of tasks handled by the ambulance fleet in northern norwaytrust20042005200620072008university hospital23,17224,33625,39226,39827,387nordland hospital17,23618,69318,95619,36019,038helgeland hospital10,17111,30510,87111,40110,731finnmark hospital12,53012,41813,06714,00114,307total63,10966,75268,28671,16071,463 activity measured in number of tasks handled by the ambulance fleet in northern norway looking at the number of kilometres driven by the fleet, there was (except for finnmark hospital trust) a stable situation with a slightly falling trend after the takeover by the nnrha in 2007. 2. this study was not designed to address causation of this trend, but we would like to mention that in 2007 we started the introduction of a fleet administration and coordination system. the mean distance driven by each car annually was 44,524 km, indicating that the cars are undergoing significant wear and tear. the figure illustrates the significant distances in our region and in particular the situation in the county of finnmark. in this district, the mean travelling distance per task (99.8 km) was 3050% above the figures at the other trusts. correlating for the number of tasks and the population (per 1,000 inhabitants), we discovered a very similar pattern in all trusts, except for finnmark hospital trust (26% higher). not surprisingly, the population of the municipalities was correlated with distance travelled (p = 0.016) and number of duties performed (p = 0.021). 2number of kilometres driven by the ambulance fleet in the four hospital trusts in northern norway during the 5-year period 20042008fig. 3number of tasks done by the ambulance service in each hospital trust in northern norway related to inhabitants (per 1,000 inhabitants) in the area number of kilometres driven by the ambulance fleet in the four hospital trusts in northern norway during the 5-year period 20042008 number of tasks done by the ambulance service in each hospital trust in northern norway related to inhabitants (per 1,000 inhabitants) in the area the number of employees in northern norway having a fagbrev rose by 20% (from 38 to 58%) during the study period. however, we are still behind the goal of 75%. focusing on the costs, there has been an increase in the running costs of the ambulance service of 92.3% during the study period. most of these expenses were due to persistent upgrade of the service and consequently lasting operating costs at a higher level. during the 5-year time period, the total expenses of the nnrha rose by 32.7% (from nkr 8,690,247 to nkr 11,535,340) (980,841 to 1,301,957), strongly indicating that significant resources have been allocated to the ambulance services. the university hospital of north norway trust had the fastest rising costs and the most expensive service. their cost per ambulance was 47% higher than the others. during the study period, the running expenses at each hospital trust are shown in table 2. in comparison, the price index in norway rose by 10.7% from january 2004 to december 2008 (www.ssb.no). table 2running expenses at each hospital trust in total cost and cost per ambulance unithospital trust20042005200620072008university hospital14,11314,49617,34527,97830,152 per unit332341408658710nordland hospital8,1888,0539,23613,40314,304 per unit278273313454485helgeland hospital4,1004,7535,7107,6938,256 per unit256297357481516finnmark hospital7,3217,1757,4229,50612,784 per unit257252260334449the costs are in 1000. the cost per unit varies significantly running expenses at each hospital trust in total cost and cost per ambulance unit the costs are in 1000. the cost per unit varies significantly the ambulance fleet did not have any electronic patient record (epr) system and medical data on patients transported could not be analysed. the running cost of the ambulance fleet in northern norway has almost doubled during the study period. whereas an increasing number of tasks have been performed, the number of kilometres driven has been stable. we have analysed the 5-year data on personnel resources and ambulance operations and focused on trends, kilometres driven and level of competence. however, we had no access to data on patients being transported and the quality of the medical service offered to them. furthermore, we did not include air or boat ambulances. when the ambulance fleet in the near future will be equipped with an epr system, data on patient care and administration while onboard can be analysed. the slight drop in number of kilometres driven at the end of the study period may be partly due to a campaign on correct use of transportation (public transportation and taxi when appropriate). another explanation may be the introduction of the transmed / transmobil fleet coordination system and consequently improved logistics. the latter is in accordance with the study by ong. who analysed ambulance calls in singapore. they reported that the utility of geographic information systems (gis) had significant implications for maximizing the effectiveness of ambulance deployment. schuessler and cotter also concluded that an effective strategic plan for the area of operations must be in place to provide a cost - effective service. this was also elucidated by dean who concluded that computer - aided dispatch (cad) systems capable of tracking unit locations outside of their stations were to be recommended. this may have caused the lack of any measurable effect on kilometres driven in this area. furthermore, they had limited access to air ambulances in late 2008 due to new european regulations concerning the staffs working time. the numbers of ambulance tasks are 36% higher in northern norway than in the other regions (central, western, southeast) air and boat ambulances are more frequently employed in our region and cause a need for an ambulance at both ends. an increasing number of communities in northern norway are arranging common casualty clinics causing an increased distance of transportation. in the future it should be discussed whether the cost of a steadily increasing number of ambulance services offered to intercommunity common casualty clinics should be taken care of by the hospital trusts or these clinics themselves. life - saving prehospital interventions are one of the main reasons for a steady upgrade of the crew. a danish study has documented that only 4% of patient contacts were life - saving and most of them were related to opioid poisoning and cardiac arrest. in april 2010, new european regulations will be introduced where every ambulance must be manned by at least one employee with a fagbrev. whereas the ambulance workers competence has been improved, a recent study revealed that only 19% of them reported their competence being appreciated by cooperating medical staff. we have invested in education and consequently improved the salary among workers hoping for an improved service. whyte and ansley evaluated a system of financial reward for emergency medical technicians who met selected quality marker goals. following the incentive, reports were completed within 3 h 99.7% of the time (64% prior to incentive). aspirin use in adult non - traumatic chest pain improved from 60 to 96.3% and ecg performance in this group improved from 43 to 87.8%. documentation of the time of onset of symptoms in stroke patients improved from 97 to 100%, and the assessment of and intervention for pain in traumatic hip pain patients improved from 56 to 100%. according to today s trend, the population of norway is aging and one third will be above the age of 67 years in 2030. this indicates a rising need for ambulance services as the elderly are more often transported by ambulance. kawakami and co - workers reported that elderly, male, low household income and no possession of a car were all factors causing an increase in the use of ambulances in non - emergency situations. these four factors together potentially produced 16.819.2% of all incremental demands, depending on scenario selected. one way of keeping the costs down may be reinstallation of the family physician as the important gatekeeper. beillon and co - workers have documented variations between less and more densely populated swedish areas with the former having a more appropriate use. jacob and colleagues asked whether the treating physician agreed with the patient s decision on transport method. there was agreement in 68% of ambulance transports and 92% of non - ambulance transports. davis and co - workers employed industrial engineering techniques in the evaluation of the efficiency and effectiveness of the services. by such means, they showed that by a reduction of the number of service units during time of least demand and combining some jobs, money could be saved without affecting the level of service. a similar system streamlining care has been described by su and shih in taiwan. when epr systems have been installed, further analysis on quality of care should be done and air and boat ambulances included. today, we hope that an improved level of competence causes medics to do the right things and do them well. however, at present we can document the improved results of the whole treatment chain, but not the specific contribution by the medics. this may be possible when the epr has been implemented. computer - based ambulance fleet coordination systems may cause reduction in distance travelled and consequently savings, but cost - effectiveness analyses should be performed. improved level of competence and an upgraded coordination system have improved logistics and hopefully treatment outcome. | backgroundthe ambulance services in northern norway have undergone significant development during recent years.aimsthe objective of this study was to describe these changes in terms of tasks performed, distance driven, resources spent and level of competence in terms of education.methodsa retrospective analysis was performed. the ambulance fleet s activity during the time period 20042008 was analysed. the subject was the ambulance fleet in northern norway and its crew members. tasks done, kilometres driven, resources spent per thousand inhabitants and level of competence were the main outcome measures.resultsthe major findings were almost doubled costs (92%), increasing number of tasks performed (13%) and a stable situation concerning kilometres driven. we also revealed improving competence in terms of education. a 20% absolute increase in crew members having a certificate of competence (fagbrev) was observed.conclusionssignificant economic resources have been invested in the fleet. improved level of competence and an upgraded coordination system have improved logistics and hopefully treatment outcome. the latter should be further elucidated when the electronic patient record (epr) system has been implemented. |
spinal cord injury (sci) has a devastating effect on daily life of the patients. the foremost and frustrating symptoms are the losses of sensory, motor, and/or autonomic functions [15 ]. spinal cord injury can be either complete or incomplete, and the symptoms for different sci individuals may vary according to the severity of the trauma. neural plasticity occurs over time at sites both above and below the level of injury, which results in both the pathophysiological complications and the functional recovery [6, 7 ]. the monoaminergic system is one of the systems that undergo drastic plastic changes in the spinal cord following sci [816 ]. in the mammalian spinal cord monoamine neurotransmitters, for example, serotonin (5-hydroxytryptamine, 5-ht), dopamine, and noradrenaline, are important modulators of both sensory and motor functions. it is commonly believed that monoamines in the spinal cord originate from different supraspinal brain regions [17, 18 ]. accordingly in complete sci the monoamines are largely gone although residual amounts still remain [11, 19 ], whereas in incomplete sci monoamines in the spinal cord are lost at a varied degree depending on the severity of the injury. recently our research group has focused on the plastic changes of serotonergic system in the spinal cord. using a sacral spinal cord transection rat model we have found that 5-ht2 (a and c) receptors are upregulated in response to complete sci [13, 14, 16 ]. more importantly, we have found that cells expressing aromatic l - amino acid decarboxylase (aadc) in the spinal cord, which normally do not contain monoamines, increase their activity and could potentially produce 5-ht in the presence of 5-ht precursor, 5-hydroxytryptophan (5-htp). following incomplete sci, either contusion or hemisection, there remains a considerable amount of 5-ht in the spinal cord below the lesion. for instance, following hemisection the remaining amount of 5-ht below the lesion is about 840% of the normal level 38 days after the lesion according to the data from different laboratories [9, 10, 2325 ]. more importantly some studies have reported a gradual recovery of 5-ht due to reinnervation to the lesion side over time [9, 10, 24 ] although this is not constantly observed [25, 26 ]. then the question is whether this 5-ht is produced from the 5-ht sprouting fibers from the uninjured side or from the intrinsic 5-ht - producing cells, such as aadc cells. this issue is investigated by using a hemisection sci rat model in the present study. we used rats with a postinjury time at either 5 days or 60 days to examine the expression of 5-ht based on the facts that the descending 5-ht fibers have been degenerated at 57 days after the transection [14, 27 ], that from 4 to 8 weeks after incomplete sci significant plastic changes have occurred in the spinal cord including the descending cortical and subcortical spinal fibers, and that at both time points the aadc cells have shown a steady increased ability to synthesize 5-ht from 5-htp. all experiments followed the guidelines of eu directive 2010/63/eu and were approved by the danish animal experiments inspectorate. twenty - nine male sprague - dawley rats with initial body weight of 160490 g during the operation were used in this study. the animals were subjected to either thoracic spinal cord hemisection operation (n = 28) or sacral spinal cord transection (n = 1). all the rats had a 12/12-hour light / dark cycle and had access to food and water ad libitum. the rats subjected to hemisection were divided into four groups and the rats in each group underwent different treatments before perfusion (see further below). before the hemisection operation, the rat was anesthetized with 2.0% isoflurane in a mixture of gas of o2 (500 psi) and n2o (200 psi). the surgical area was shaved and cleaned with alcohol and the whole operation was carried out under sterile conditions. a 0.2 ml mix of sedatives and local anesthesia (xylocaine 12.5 mg / ml and marcaine 2.5 mg / ml) were given intramuscularly. also, a nonsteroidal anti - inflammatory drug and a postoperation pain relieving drug (rimadyl, 5 mg / kg) were given subcutaneously. the dura was opened and about 1 - 2 mm of the spinal cord at level t11-t12 was removed at one side without damaging the dorsal vein or ventral artery. the wound was then closed by stitching the muscle, fascia and skin separately with a monofilament suture. for one rat that was subjected to spinal cord transection at the second sacral level (s2) the surgery procedure has been described elsewhere ; that is, a small piece of the spinal cord tissue at s2 level was completely removed. after the operation, the rat was subcutaneously treated with analgesic (temgesic 0.1 mg / kg) at every 8 hours for the first 48 hours. the welfare of the animals was controlled every day until the end of the experiments. initially the 28 spinal hemisected rats were divided into two time groups : 16 rats in a 5-day postoperation group and 12 rats in a 60-day postoperation group. in each time group the rats were further divided into two subgroups subjected to different treatments. however, due to compromised welfare of three animals in the 5-day group they had to be euthanized before the planned time. thus in the end there were 25 rats in total in the four groups : 14 rats were used in experimental groups or treated groups (8 in the 5-day group and 6 in the 60-day group, resp. mg / kg) combined with carbidopa (20 mg / kg) in saline with a small amount of hydrochloride acid 30 min before the perfusion. the other 11 rats were used as control animals or untreated groups (5 in the 5-day group and 6 in the 60-day group, resp., table 1) and the rat whose spinal cord was transected at s2 level was treated in the same way as those in the experimental groups. all the rats were euthanized with pentobarbital 50 mg / ml and perfused intracardially with 200300 ml 0.01 m phosphate buffered saline (pbs) for 3 - 4 min, followed by a 400 ml solution of 4% paraformaldehyde in 0.1 m phosphate buffer over 15 min. the entire spinal cord was removed and postfixed in the original fixative for 24 hours at 4c and cryoprotected in pbs with 30% sucrose for 24 hours at 4c. upon the removal of the spinal cord all the spinal cord hemisected rats used in this study were demonstrated to have been hemisected at t11 or t12 level on one side. the spinal cord was separated into different segments and the lumbar and sacral parts were cut horizontally into 40 m sections. if the spinal cord was not cut after 48 hours, it was cryoprotected in a 0.01 m pbs solution containing 15% sucrose, 30% ethylene glycol, and 0.05% thimerosal and stored at 20c. every second section from lumbar (l1l6) and sacral (s1-ca3) levels from all the rats was processed for 5-ht and aadc double immunofluorescence staining. the sections were rinsed in pbs twice for 10 min each and in pbs with 0.1% triton x-100 (pbst) once for 10 min. then the sections were preincubated in pbst containing 2% bovine serum albumin and 5% normal donkey serum for an hour. after rinsing in pbst for 10 min, the sections were incubated in the same solution containing rabbit anti-5-ht (1 : 10000, immunostar) and sheep anti - aadc (1 : 200 ; millipore - chemicon) primary antibodies diluted over 24 hours at room temperature. following rinsing four times in pbst for 15 min each the sections were incubated for an hour in donkey anti - rabbit alexa fluor 594 (1 : 200, invitrogen), donkey anti - sheep alexa fluor 488 (1 : 200, invitrogen) in pbst with 1% bovine serum albumin, and normal donkey serum 2% at room temperature. after rinsing three times in pbs for 10 min each the sections were mounted, dried, and coverslipped with fluorescence mounting medium (dako). the spinal sections were observed with a fluorescence microscope (leica dm6000b, leica microsystems, wetzlar, germany). all the images were captured digitally (leica dfc420 c digital camera system) and processed with adobe photoshop cs6. to compare with the results from our previous study where the rat spinal cord was transected at s2 level we only analyzed the data acquired from sacrocaudal level in this study. for the analysis of the density of 5-ht - immunoreactive (ir) fibers, paired images were taken with an imaging area of 1000 m 750 m from the intermediate gray matter / zone and the ventral motoneuron region from both sides of the selected sections. to avoid bias in the quantitative data analysis due to varied spinal locations images from the injured and uninjured sides the density of 5-ht - ir fibers was analyzed with image j software [13, 14 ]. to do this the image was first thresholded and then the area above the threshold level was calculated and the data from injured and uninjured sides were compared. the distribution of aadc cells and the incidence of 5-ht - ir aadc cells at s1-ca3 were analyzed in the intermediate zone using a md - plotting system (accustage) as has been described previously. the aadc cells and the 5-ht - ir aadc cells were plotted with different symbols. the relative quantity of aadc cells was expressed as cell number per section and the incidence of 5-ht - ir aadc cells was expressed as percent aadc cells for each animal. standard deviation (sd) was used to represent data variations from the mean value. paired t - test (or wilcoxon signed rank test if the data were asymmetrically distributed) or unpaired t - test (or mann - whitney rank - sum test if the data was asymmetrically distributed) was used for the comparison of data between two groups and the significance level was set at p 0.05 for the two time groups), indicating that hemisection and drug application did not alter the expression of aadc cells in the injured side (table 1). therefore we decided to pool the data from the untreated group and the treated group together. in the 5-day group the number of aadc cells in the intermediate zone on the injured side was 19.60 7.07/section whereas on the uninjured side it was 17.88 8.02/section (n = 13). no significant difference was found between the two sides (p = 0.721, paired t - test). similarly, in the 60-day group the number of aadc cells in the intermediate zone on the injured side was 10.13 4.82/section whereas on the uninjured side it was 8.98 4.56/section (n = 12). no significant difference was found between the two sides (p = 0.128, paired t - test). since we did not systematically plot the aadc cells in all the sections no attempt was made to make a quantitative comparison of aadc cells between the 5-day and the 60-day groups. because the main purpose of this study was to investigate whether aadc cells increased their ability to produce 5-ht from 5-htp following hemisection, we have examined 5-ht expression in aadc cells in two different animal groups following 5-htp + carbidopa application. 5-ht - positive aadc cells were examined at the sacrocaudal level in both the untreated and the treated group in 5-day and 60-day rats. in addition 5-ht - positive aadc cells were also examined in the spinal cord from the rat subjected to a complete spinal transection at s2 level and the results showed that 100% of the aadc cells in the intermediate zone became 5-ht - ir in this rat (data not shown). in the untreated groups no aadc cells became 5-ht - positive on both the injured and the uninjured side of the spinal cord in both 5-day and 60-day groups. in the 5-day treated group we have observed a certain number of 5-ht - ir aadc cells on both the injured side and uninjured side in 7 out of 8 cases (figures 3(a) and 3(b)). quantitative analysis showed that 42.52 19.15% (n = 8) of aadc cells became 5-ht - positive on the injured side whereas only 25.25 17.81% (n = 8) of the aadc cells became 5-ht - ir on the uninjured side. the difference was significantly different (p < 0.01, power = 0.85 with = 0.05, paired t - test) (figure 3(c)). in 60-day treated group we observed a certain number of 5-ht - ir aadc cells in 3 out of 6 rats in the injured side and 2 out of 6 rats in the uninjured side (figures 3(d) and 3(e)). quantitative analysis showed that 15.98 18.72% (n = 6) of the aadc cells on the injured side became 5-ht - ir while 9.57 15.00% (n = 6) of aadc cells on the uninjured side became 5-ht - ir. the difference between the injured and uninjured sides was not statistically significant (p = 0.25, wilcoxon signed rank test) (figure 3(f)). further, we have compared the data in the two time groups treated with 5-htp and carbidopa. the results revealed that on the injured side the incidence of 5-ht - ir aadc cells in 5-day group was significantly higher than that in 60-day group (p < 0.05, power = 0.59 with = 0.05, t - test), whereas on the uninjured side the difference was not significant (p = 0.096, power = 0.27 with = 0.05, t - test). due to large variations for the 5-ht - ir aadc cells in different drug treated groups we speculate whether this was related to the variations of 5-ht fiber denervation. thus we have made a pearson product - moment correlation analysis between incidences of 5-ht - ir aadc cells and the densities of 5-ht fibers in different drug treated groups and the results showed no correlation between the density of the 5-ht - ir fibers and the number of 5-ht - ir aadc cells. actually, the variation of the density of 5-ht - ir fibers was relatively small within a specific group / side (table 1), which indicates that the higher incidences of 5-ht - ir aadc cells in some cases were due to other facts (see discussion). in the present study using thoracic hemisection rat model we found that, first, 5-ht - ir nerve fibers in both the intermediate zone and the ventral horn motoneuron region were dramatically reduced on the injured side in comparison with the uninjured side for both 5-day and 60-day groups, and this decrease did not recover in animals with a longer survival time ; second, there was no significant expression difference for the aadc cells on the injured side and uninjured side for both time groups ; and third, the aadc cells increased their ability to synthesize 5-ht from its precursor, 5-htp, at 5 days but not at 60 days after injury. these results indicate different plastic changes may occur for the spinal cord which is subjected to a partial or a complete injury. there are many investigations to examine the plastic changes of 5-ht fibers with different sci animal models. the density of 5-ht fibers in the spinal cord after sci varies in relation to many different factors which include, among others, the severity of the injury, the postinjury time, and the locations in the spinal cord. for example, when the spinal cord was completely transected usually just a few 5-ht - ir fibers were observed below the lesion in the intermediate zone and/or the ventral horn following more than two months of injury [14, 15, 28 ]. in contusion injury the density of remaining 5-ht fibers below the lesion depends on the locations along the dorsoventral axis and the severity of the injury. in hemisection the density of 5-ht fibers in the ventral horn was reported at a range from 8% to 30% of the control value according to different studies with a postinjury time window from 4 to 7 days [9, 23, 25, 26 ]. hains. found that, in the dorsal horn (laminae i - ii), following 3-day of hemisection at thoracic level, ~30% 5-ht - ir fibers remain in the lumbar spinal cord. our 5-ht fiber data from 5-day animals in the intermediate zone and the motoneuron region are in general agreement with that reported in the dorsal horn and the ventral horn, indicating that 5-ht fibers may undergo a similar degradation process in different parts of the gray matter. an apparent discrepancy exists in the literature as to whether 5-ht fibers recover over time after spinal hemisection. some studies have reported a gradual increase of 5-ht - ir fibers on the ipsilateral side below the lesion [9, 10, 24 ] whereas some others did not (e.g.,). for example, saruhashi. observed that from first week to the fourth week the 5-ht - ir fibers recovered from 20% to about 75% of the normal value in the ventral horn. also reported similar results although with slight variations in the intermediate zone and dorsal horn, respectively. on the contrary, filli. reported a decrease to about 10% by 4 weeks from about 30% at day 4. 's in that by 60 days the density of 5-ht - ir fibers in the intermediate zone was reduced to 11% from 23% at 5 days. in the motoneuron region although the value was not reduced so much (23% versus 22%) it neither increased. there might be several explanations for this discrepancy. first, the different locations in the spinal gray matter may undergo different plastic changes of 5-ht innervations. in our study 5-ht fiber density in the ipsilateral intermediate zone decreased more than in the motoneuron region upon 60 days, which may indicate that the intermediate zone is less affected by 5-ht axon reinnervation. second, upon 5 days after injury the 5-ht fibers may not drop to the lowest level. it may take 2 - 3 weeks for the degenerated 5-ht fibers to completely disappear. in this case third, it might be more logical to compare the data from the injured side with the normal control animal rather than the uninjured sides, since hemisection could also affect the 5-ht fiber density in the uninjured side considering the existence of crossing 5-ht fibers. in addition, different lesion level, slight lesion variations, and different analysis methods may also result in different 5-ht density output. in any way, further studies are needed to find out which factor(s) is (are) involved in causing this discrepancy. we observed that the density of 5-ht - ir fibers in the intermediate zone increased on both sides in 5-day group and on injured side in 60-day group after combining 5-htp and carbidopa injections, and the density decreased in the motoneuron region for both sides in the two time groups. it is easy to understand the increase due to the increased availability of 5-ht precursor in the 5-ht fibers. however, it is bewildering that 5-ht fiber density decreased with addition of 5-htp. one possible explanation may be that the contribution of 5-ht fibers from the aadc cells is very limited presumably due to their poor fiber arborization. in this case, what we saw in the motoneuron region is just the results representing approximately those prior to 5-htp application. similar to our study using complete spinal transection rat model we did not observe aadc cell expression changes on the injured side.. 's observation that aadc cells are only expressed in the region around the central canal and that only after spinal transection they start to appear in the intermediate zone. the results from our group thus indicate that the number of aadc cells is not increased in response to sci although aadc plastic changes at molecular level can not be excluded. one of the main purposes of the present study is to examine whether aadc cells increase their ability to produce 5-ht from its precursor, 5-htp. it has been reported both from our and bennett 's research group that after complete spinal transection aadc cells in the spinal cord increase their efficacy to catalyze 5-htp [22, 29 ]. in the present study we have observed an increased enzymatic ability in spinal aadc cells on the injured side at 5 days but, to our surprise, not at 60 days although the results are not conclusive due to the lower statistical power in the 60-day group. thus we have observed a different aadc activity in response to complete spinal transection and hemisection. at 5 days after either complete spinal transection or hemisection aadc cells dramatically increase their ability to use 5-ht precursor to synthesize 5-ht (; present study). this rapid response of aadc cells in the spinal cord may be a response to a sudden loss of supraspinal 5-ht innervation, and thus through the deactivation of 5-ht1b receptors aadc cells are activated. after spinal hemisection both intraspinal and supraspinal plasticity occur which will help eventually to reestablish anatomical and functional circuits in the spinal cord. in addition to the descending 5-ht pathway other descending pathways, such as corticospinal, rubrospinal, and reticulospinal pathway, may also have an inhibitory effect on the spinal aadc cells. a large body of evidence has indicated that extensive plasticity occurs usually after 2 - 3 weeks of injury (reviewed by nardone.). have found that 5-ht release in the lumbar ventral horn showed about 200% increase at day 18 relative to day 8 following subhemisection. meanwhile plastic changes of many other pathways, including intraspinal and descending pathways, may reorganize and reestablish functional circuits in the spinal cord [6, 32 ]. all the above factors may contribute to reestablishing an inhibitory network for the aadc cells in the chronic phase following hemisection. in spinal transection these descending pathways, including 5-ht pathway, will not recover below the lesion ; thus aadc cells will continue to be active in the chronic phase. 5-ht is an important neuromodulator for both motor and sensory functions in the spinal cord [11, 30 ]. numerous studies have illustrated that locomotor activity can be recovered following 5-ht or its precursor application or transplantation of 5-ht - producing cells in the spinal cord after spinal cord transection [30, 3336 ]. thus it is extremely important that after sci there are sources in the spinal cord that could produce 5-ht. evidence from complete spinal cord transection studies showed that the activity of aadc cells is increased in both the subchronic and chronic phase and 5-ht produced from these cells could induce increased motoneuron excitability and thus muscle spasms. our results in the present study indicate that after hemisection a plastic change occurs for aadc cells in that in the subchronic phase they could increase their ability to potentially provide 5-ht if its precursor is available. although aadc cell activity is not significantly increased in chronic phase the cells may help to maintain the reestablished spinal network which is essential for functional recovery of the spinal cord in later phase. actually in agreement with many other studies (e.g., [9, 25 ]) we observed a motor function recovery over time in the body parts below the hemisection in 60-day rats without giving any external interventions. it deserves further investigation as to how much aadc cells contribute to this functional recovery. | neuromodulators, such as serotonin (5-hydroxytryptamine, 5-ht) and noradrenalin, play an essential role in regulating the motor and sensory functions in the spinal cord. we have previously shown that in the rat spinal cord the activity of aromatic l - amino acid decarboxylase (aadc) cells to produce 5-ht from its precursor (5-hydroxytryptophan, 5-htp) is dramatically increased following complete spinal cord transection. in this study, we investigated whether a partial loss of 5-ht innervation could similarly increase aadc activity. adult rats with spinal cord hemisected at thoracic level (t11/t12) were used with a postoperation interval at 5 days or 60 days. using immunohistochemistry, first, we observed a significant reduction in the density of 5-ht - immunoreactive fibers in the spinal cord below the lesion on the injured side for both groups. second, we found that the aadc cells were similarly expressed on both injured and uninjured sides in both groups. third, increased production of 5-ht in aadc cells following 5-htp was seen in 5-day but not in 60-day postinjury group. these results suggest that plastic changes of the 5-ht system might happen primarily in the subchronic phase and for longer period its function could be compensated by plastic changes of other intrinsic and/or supraspinal modulation systems. |
pulmonary tumor thrombotic microangiopathy (pttm) also known as carcinomatosis endarteritis is a highly fatal respiratory complication seen in cases of malignancies especially adenocarcinomas of the stomach. there are only around 80 cases reported in literature so far including less than 10 cases where the primary malignancy has not been detected even after extensive search. we present an autopsy case of a 47-year - old male patient who developed acute breathlessness and died suddenly. at autopsy there was mild right ventricular dilatation and lungs showed few firm areas and prominent bronchovasculature. on microscopy, the lungs showed the presence of florid fibrocellular intimal proliferation of the arterioles and small arteries [figure 1 ]. vessels showed fibrin thrombi and occasional vessel showed tumor emboli composed of neoplastic adenocarcinoma cells showing glandular and occasional signet ring morphology. there were similar tumor emboli in the myocardium, peripancreatic tissue, and perigastric lymph nodes [figure 3 ]. despite extensive sectioning no primary tumor tumor cells were negative for ck 7, ck10, ttf 1, and psa. the final cause of death was given as acute cor pulmonale following pulmonary tumor thrombotic microangiopathy in an unknown primary adenocarcinoma. lungs showing presence of florid fibrocellular intimal proliferation with fibrin thrombi of the arterioles and small arteries (h and e, 100) lungs showing presence of lymphangiosis carcinomatosis (h and e, 100) signet ring cells seen in the lymph nodes (h and e, 400) pttm is characterized by intimal proliferation in pulmonary small arteries and arterioles with or without tumor emboli leading to vascular stenosis and pulmonary hypertension. there was florid fibrointimal proliferation, fibrin thrombi with some showing occasional tumor emboli and lymphangimatosis carcinomatosis. the tumor cells in this condition invade the pulmonary vascular system occluding the small arteries, arterioles and activate coagulation systems releasing inflammatory mediators, growth factors like serotonin, vascular endothelial growth factor and osteopontin. some authors have proposed screening with serum vegf and d - dimer testing for early detection of pttm. the primary sites of malignancy reported are gastrointestinal tract, ovary, breast, pancreas, liver, uterus, gall bladder, and prostate. however, rarely there are reported cases where primary has not been detected inspite of extensive search and immunohistochemical stains. in our case too despite an extensive search no primary mass was found. thus, our case belongs to the rare set of pttm with unknown primary of which only less than 10 cases have been reported. it should be distinguished from ordinary pulmonary thromboembolism and primary pulmonary hypertension and should be considered as a differential diagnosis in patients with acute respiratory symptoms especially in cases with an underlying cancer. there are only occasional case reports of antemortem diagnosis with patient recovering completely, and hence it is important to have a higher clinicopathological awareness of diagnosing this highly fatal condition. role of 2-(f-18)-fluoro-2-deoxy - d - glucose positron emission tomography (fdg - pet) has been described in literature and has been described to be helpful for the diagnosis of pttm. | pulmonary tumor thrombotic microangiopathy (pttm) is a highly fatal complication of cancer leading to acute cor pulmonale and pulmonary hypertension. we present a case of 47-year - old male patient who developed acute breathlessness and died suddenly. the pulmonary vessels at autopsy on histopathologic examination showed the presence of fibrocellular intimal proliferation, fibrin thrombi and few tumor emboli consisting of malignant adenocarcinoma cells. there was associated lymphangiosis carcinomatosis. no primary visceral tumor was found despite extensive search. the patient had died following acute cor pulmonale with sudden pulmonary hypertension due to pttm. this entity (pttm) must be kept as a differential diagnosis in patients presenting with acute breathlessness especially in cases of cancers. |
teratoid wilms tumor, a rare variant of nephroblastoma, has a predominance of heterologous elements. to date less than 30 cases of teratoid wilms tumor have been reported in the literature.[13 ] there is only one case in the literature, which has the squamous epithelial component comprising 70% of the tumor. we describe a case in which the squamous epithelium with keratin cysts comprised majority (about 75%) of tumor mass. metastasis is seldom reported in teratoid wilms. a -2-year - old boy presented with palpable mass on the right side of abdomen for 2 months. physical examination revealed a firm mass that was palpable in the lumber region. contrast - enhanced computed tomography (cect) scan showed large hetrodense lesion in the right lumber region measuring 17 cm 8 cm 7 cm. the right lung showed nodular opacities in posterior and lateral basal segments of about 0.5 cm in diameter suggestive of metastasis. cect scan done after 6 weeks of chemotherapy showed little change in the size of tumor and the patient underwent nephrectomy. grossly, nephrectomy specimen measured 17 cm 8 cm 6 cm that was soft in consistency. the cut section was predominantly solid and pale grey with areas of cystic change, necrosis, and hemorrhage. a thin segment of normal kidney was seen compressed at periphery [figure 1 ]. gross - predominantly cystic appearance of teratoid kidney microscopically, the tumor showed classical triphasic pattern with blastemal, epithelial, and mesenchymal components without anaplasia ; about 75% of the tumor revealed areas of squamous differentiation with keratin pearl formation but without adnexal structures [figures 2 and 3 ]. there were also small foci of mature adipose tissue and glial tissue [figure 4 ]. wilms tumor is an embryonic tumor typically composed of variable admixture of blastematous, epithelial and stromal components. wilms tumor can include heterologous elements in addition to these components and variend in 1984, coined the term teratoid wilms tumor for them.. defined teratoid wilms as a tumor that contains hetrologous elements comprising more than 50% of the tumor mass. to date, less than 30 cases of teratoid wilms tumors have been reported.[13 ] the pathogenesis of this entity is still debated ; it is likely that it originates from totipotent primitive metanephric blastema. the variable presence of intracellular matrix proteins may influence the presence, extent, and diversity of hetrologous differentiation. the teratoid elements seen frequently are skeletal muscle, smooth muscle, adipose tissue, glial tissue, cartilage, bone, and are generally assumed to represent aberrant mesenchymal differentiation. there is only one case of teratoid wilms in the literature, reported by karaka i, which had squamous epithelial component comprising 70% of the tumour. we report a case that showed the familiar triphasic pattern of nephroblastoma along with the extensive squamous epithelial components constituting about 75% of the tumor. the differential diagnosis of teratoid wilms is intrarenal teratoma, metastatic germ cell tumor, and retroperitoneal infiltration of teratoma. in our case, classical triphasic pattern of wilms tumour was seen and there was no attempt to form the adnexal structures or organogenesis thus ruling out intrarenal teratoma. also, the presence of normal testis excluded the possibility of metastatic testicular germ cell tumor. renal capsule was also free of tumor so retroperitoneal infiltration of teratoma was also ruled out. although it is reported that teratoid wilms tumor is not usually aggressive or has metastatic potential. the case reported by karaka, which had extensive squamous areas, died of metastasis. whether the squamous differentiation is associated with higher stage at presentation remains to be seen. the treatment of teratoid wilms tumor has not yet been established because of its rarity and varying tumor components. both surgeons and pathologists should be aware that the treatment of this rare variant should be focused on total surgical removal of the tumor. | teratoid wilms tumor is an unusual histological variant of nephroblastoma with predominant heterologous component. frequently present components include adipose tissue, glial tissue, muscle, cartilage or bone. the presence of squamous epithelial component on the other hand is rarely reported. we describe a case of unilateral teratoid wilms tumor in a 2-year - old boy with lung metastasis. in this case, tumor showed the familiar triphasic histologic pattern of nephroblastoma along with extensive squamous epithelial component. |
if this balance is disrupted, demineralization will progress, leading to a deterioration of the tooth structure. calcium and phosphate are lost from the subsurface enamel, resulting in the formation of a subsurface lesion. at this early stage, the caries lesion is reversible via a remineralization process involving the diffusion of calcium and phosphate ions into the subsurface lesion to restore the lost tooth structure. as several studies had demonstrated that milk - based products appeared to have anticariogenic properties in animal models, attention was focused on identifying the specific milk - based agents that were responsible for the anticaries effect the concept of casein phosphopeptide - amorphous calcium phosphate as a remineralizing agent was first postulated in 1998. cpp - acp nanocomplexes are derived from bovine milk protein, casein, and calcium and phosphate. a number of subsequent studies have demonstrated cpp - acp to have anticariogenic activity in laboratory, animal and human in situ experiments. modern prospective caries studies require the measurement of small changes in a tooth 's mineral content, especially in a single caries lesion. one recent technique is scanning electron microscopy with an energy dispersive x - ray analysis attachment. it is a microanalytical technique that is employed to quantitatively estimate the amounts of mineral in a given tooth sample. the anticariogenic activity of cpp - acp has led to its incorporation into food products and dental products as a new tool in the fight against dental caries. hence, the aim of this study was to assess the remineralization potential of casein phosphopeptide - amorphous calcium phosphate paste on enamel subsurface lesions. ninety enamel specimens, 4 mm 4 mm 1 mm in size, were prepared from the buccal surfaces of extracted human molar teeth using a low - speed diamond disc. all specimens were evaluated for mineral content (% weight) using sem - edx [figure 1 ]. the specimens were placed in the demineralizing solution containing 20 ml of acid buffer with 2 mmol / l ca, 2 mmol / l po4, and 0.075 mol / l acetate at ph 4.3 for four days at 37c to produce artificial carious lesions. all specimens were evaluated for any loss of mineral content (wt %) using sem - edx on the 5 day [figure 2 ]. elemental analysis of sound enamel sample by edx elemental analysis of demineralized enamel sample by edx the specimens were randomly assigned to two groups : group 1 contained 15 specimens (control group) and group 2 contained 75 specimens (study group). each subgroup was treated with remineralizing paste [10% cpp - acp paste (gc - tooth mousse) ] using a stainless steel spatula for seven days (subgroup 2a), 14 days (subgroup 2b), 21 days (subgroup 2c), 28 days (subgroup 2d), and 35 days (subgroup 2e), twice daily for three minutes followed by incubation in artificial saliva at 37c. the specimens in the control group (group 1) were incubated in artificial saliva at 37c after demineralization for a period of 35 days but received no treatment with remineralizing paste. the present study evaluated the remineralization potential of cpp - acp paste on artificial enamel subsurface lesions using sem - edx. energy dispersive x - ray analysis was used to determine calcium and phosphorus content in % weight of sound, demineralized, and remineralized enamel in each group. the calcium and phosphorus content was then converted into ca / p ratios for each group from the obtained data. figures 37 demonstrates the elemental analysis of study groups [sub groups 2a 2e ] for different periods of treatment time with cpp - acp. table 1 : illustrates comparision of mean ca / p ratios of sound, demineralized, remineralized enamel samples. elemental analysis of enamel sample by edx, after 7 days of remineralization elemental analysis of enamel sample by edx, after 14 days of remineralization elemental analysis of enamel sample by sem, after 21 days of remineralization elemental analysis of enamel sample by sem, after 28 days of remineralization elemental analysis of enamel sample by sem, after 35 days of remineralization comparision of mean ca / p ratios of sound, demineralized, remineralized enamel samples using one - way anova statistical analysis was done using one - way anova, tukey 's hsd, and student t - test. comparison of ca / p ratios of the sound enamel samples and ca / p ratios of the demineralized enamel samples in all the groups using one - way anova revealed that there was no statistically significant difference between the groups. one - way anova was applied to compare the mean ca / p ratios of the study groups after remineralization, which was found to increase to 1.93 0.02 on the 35th day. this increase in the mean ca / p ratio from the seventh to the 35 days had p < 0.0005, implying a very high statistically significant difference in the remineralization potential over this period. tukey hsd was done for intergroup comparison [table 2 ] and p < 0.0005 for all the comparisons suggested very high significance. intergroup comparison of the remineralization potential of study groups done using tukey honestly significant difference post hoc multiple comparisons the t - test was done to statistically analyze the mean ca / p ratios of demineralized and remineralized specimens in each group [table 3 and figure 8 ]. the value of significance was set at p < 0.05 and it was seen that all the study groups revealed highly significant results between the ca / p ratios of the demineralized and remineralized samples. enamel specimens treated with cpp - acp paste revealed slight changes in their morphological features. t - test to analyze the mean ca / p ratios of demineralized and remineralized specimens in study groups relationship between demineralization and the remineralization potential of study groups structural analysis of sound enamel sample by sem structural analysis of demineralized enamel sample by sem structural analysis of enamel sample by sem, after 7 days of remineralization structural analysis of enamel sample by sem, after 14 days of remineralization structural analysis of enamel sample by sem, after 21 days of remineralization structural analysis of enamel sample by sem, after 28 days of remineralization structural analysis of enamel sample by sem, after 35 days of remineralization in the present study, the remineralization potential of cpp - acp for enamel subsurface lesions was evaluated using sem - edx. gc tooth mousse is a water - based, lactose - free creme containing 10% w / w recaldent cpp - acp. when cpp - acp is applied in the oral environment, it will bind to biofilms, plaque, bacteria, hydroxyapatite, and soft tissue, localizing bioavailable calcium localizes and phosphate. cpp - acp thus, localizes acp on the tooth surface, and buffers the free calcium and phosphate ion activities, helping to maintain a state of supersaturation with respect to the enamel by suppressing demineralization and enhancing remineralization. it is proposed that the peptide binds to the forming acp nanoclusters, producing a metastable solution and preventing acp growth to the critical size required for nucleation and phase transformation. a 1.0% w / v cpp solution can stabilize 60 mmol / l cacl2 and 36 mmol / l sodium phosphate at ph 7.0 to form colloidal amorphous calcium phosphate - cpp nanocomplexes. the remineralization process involves diffusion of calcium and phosphate ions through the protein / water - filled pores of the carious surface enamel into the body of the enamel lesion. once in the body of the enamel lesion, these calcium and phosphate species increase the activities of ca and po4, thereby increasing the degree of saturation with respect to hydroxyapatite. the formation of hydroxyapatite in the lesion would lead to the generation of acid and phosphate, which would diffuse out of the lesion along a concentration gradient. by stabilizing calcium phosphate in a metastable solution, the cpp facilitates high concentrations of calcium and phosphate ions, which can then diffuse into the enamel subsurface lesion. the cpp will also maintain high activities of the free calcium and phosphate ions during remineralization through the reservoir of the bound acp. by being in dynamic equilibrium with free calcium and phosphate ions, the bound acp will maintain the concentrations of the species involved in diffusion into the lesion. furthermore, dissociation of the cpp - bound acp will be facilitated by the acid generated during enamel remineralization. this would explain why cpp - supported, metastable calcium phosphate solutions are such efficient remineralizing solutions, as they would consume the acid generated during enamel lesion remineralization by generating more calcium and phosphate ions, thus maintaining their high concentration gradients into the lesion. in the present study, a paste type formulation of cpp - acp was used. patients can use this kind of oral hygiene paste just like tooth paste with tooth brushes and also apply the paste with cotton slabs. it is a microanalytical technique that is used in conjunction with sem wherein sem does the structural analysis and the elemental analysis is done by edx. the principle is based on the energy emitted in the form of x - ray photons when electrons from external sources collide with the atoms in a material, thus generating characteristic x - rays of that element. when the sample is bombarded by the electron beam of the sem, electrons are ejected from the atoms on the specimen 's surface (secondary electrons). a resulting electron vacancy is filled by an electron from a higher shell, and an x - ray is emitted (characteristic x - rays) to balance the energy difference between the two electrons. the edx x - ray detector measures the number of emitted x - rays vs. their energy. the energy of the x - ray is characteristic of the element from which the x - ray was emitted. a spectrum of the energy vs. relative counts of the detected x - rays is obtained and evaluated for qualitative and quantitative determinations of the elements present in the specimen using a computer - based program. the results of this in vitro study showed that 10% cpp - acp paste remineralized subsurface lesions in human enamel. the remineralization was maximal in the samples kept for 35 days, thus, it could be said that the remineralization was dose - dependent. the results of this study were consistent with the proposed remineralization mechanism of cpp - acp and are in accordance with the one obtained by reynolds who demonstrated that cpp - stabilized calcium phosphate solutions remineralized subsurface lesions in human enamel in vitro. according to yamaguchi. hegde. and oshiro. the inorganic components contained in high concentrations in cpp - acp acted to enhance remineralization of the enamel. enamel specimens treated with cpp - acp paste revealed slight changes in their morphological features. the surface morphologies of the specimens in the study groups showed no apparent differences among the different storage periods. within the limitations of this study, the following conclusions can be drawn : 10% cpp - acp paste significantly remineralized the artificial enamel subsurface lesions in vitro.the remineralization achieved was dose - dependent as the remineralizing rate increased with the time for which the enamel was exposed to the cpp - app paste.edx was found to be an efficient way to quantitatively assess the changes in mineral content during in vitro caries studies. the remineralization achieved was dose - dependent as the remineralizing rate increased with the time for which the enamel was exposed to the cpp - app paste. edx was found to be an efficient way to quantitatively assess the changes in mineral content during in vitro caries studies. | aim : the objective of this study was to quantitatively evaluate the remineralization potential of casein phosphopeptide - amor - phous calcium phosphate paste on enamel subsurface lesions using scanning electron microscopy with energy dispersive x - ray analysis (sem - edx).materials and methods : ninety enamel specimens were prepared from extracted human molars. all specimens were evaluated for mineral content (% weight) using sem - edx. the specimens were placed in demineralizing solution for four days to produce artificial carious lesions. the mineral content (calcium / phosphorus ratios, ca / p ratios) was remeasured using sem - edx. the specimens were then randomly assigned to five study groups and one control group of 15 specimens per group. except for the control group, all group specimens were incubated in remineralizing paste (cpp - acp paste) for 7, 14, 21, 28, and 35 days twice daily for three minutes. the control group received no treatment with remineralizing paste. all the 90 specimens were stored in artificial saliva at 37c. after remineralization, the mineral content (% weight) of the samples was measured using sem-edx.results:all the study groups showed very highly significant differences between ca / p ratios of the demineralized and remineralized samples. there was no significant difference seen in the control group.conclusion:cpp-acp paste could significantly remineralize the artificial enamel subsurface lesions in vitro : the remineralizing rates increasing with the time for which the samples were kept in the remineralizing paste. energy dispersive x - ray analysis is an efficient way to quantitatively assess the changes in mineral content during demineralization and in vitro remineralization processes. |
hypertension and type 2 diabetes mellitus (dm) are among the main risk factors for the development of cardiovascular disease (cvd). endothelial dysfunction, associated with dm and hypertension, is considered an early marker of vascular complications and a pathophysiological determinant of atherogenic processes. pharmacotherapy for dm should not only improve blood glucose control, but also provide beneficial glucose - independent cardiovascular effects. dipeptidyl peptidase-4 (dpp-4) inhibitor is an incretin - based drug approved for the treatment of dm. this medication reduces the breakdown of glucagon - like peptide 1 (glp-1), thereby increasing circulating glp-1 levels, improving metabolic control by increases in insulin secretion, followed by decreases in glucagon secretion. recently, several methods have been developed to assess endothelial function, and predict the presence or absence of coronary heart disease (chd). applanation tonometry (at) of the radial artery is a noninvasive method that indirectly assesses arterial stiffness by calculating the central blood pressure (bp) and the augmentation index (aix). the aix is associated with cardiovascular risk, and is a predictor of chd development. more recently, the central systolic blood pressure (sbp) of the aortic or carotid arteries has become more important than the brachial sbp in the assessment of cardiovascular risk. this case report describes a possible pleiotropic action of a dpp-4 inhibitor (vildagliptin) on the central sbp assessed by at in a hypertensive diabetic woman. this pharmacological class seems to have action in reduction of central bp and arterial stiffness. thus, we justify the possible pathophysiological mechanisms involved in the association between hyperglycemia, endothelial dysfunction, and vascular stiffness, besides how the glp-1 system provides beneficial effect on the endothelium. the patient was a 54-year - old white woman with a 4-year history of hypertension and dm. she was taking metformin (850 mg / d), pioglitazone (30 mg / d), simvastatin (10 mg / d), amlodipin (5 mg / d), and enalapril (10 mg / d) ; however, she did not adhere to a diet to control the diabetes. her physical examination revealed bp : 123/85 mm hg, heart rate : 78 bpm, body mass index (bmi) : 29.1 kg / m, and waist circumference : 91 cm. she had no abnormalities of the heart, lungs, or abdomen. according to complementary exams, the patient had poor diabetic control with glycosylated hemoglobin (hba1c) : 11.2% ; however, microalbuminuria and other biochemical parameters were normal. the patient received guidance to modify her lifestyle including diet and exercise, and vildagliptin (100 mg / d) was added to her drug regimen. the patient was submitted to examinations of the radial artery using a commercially available automated at system (hem-9000ai ; omron healthcare co., ltd, kyoto, japan) before receiving vildagliptin and 3 months after to evaluate the drug 's effect on the central sbp and aix. this examination was performed in a quiet controlled environment (temperature between 21c to 24c), between 8 am and 10 am, after the patient was rested for at least 10 minutes sitting with the legs uncrossed, the bladder empty, and away from acute stressors. the patient was instructed to fast starting the night before testing and to refrain from ingesting alcohol or caffeine. the at equipment uses a radial ultrasonic transducer and cuffs with the correct size for the arm circumference as recommended by the guidelines to evaluate bp. pulse wave analyses were performed at least 3 times and the mean of measurements was calculated. variations of bp between the measurements should not be > 5%. at the end of the 3-month follow - up period, the patient had good adherence to diet and exercise and had lost 3 kg, presenting with a bmi of 27.5 kg / m, and an office bp of 100/70 mm hg. central sbp and aix were lower than in the baseline results. before the association of vildagliptin and metformin, the peripheral sbp was 129 mm hg during the at. the central sbp (aortic) and adjusted aix for a heart rate of 75 bpm (aix75) were 127 mm hg and 96%, respectively (figure 1a). after receiving vildagliptin for 3 months, the peripheral sbp was 116 mm hg, central sbp was 101 mm hg, and aix75 was 72% (figure 1b) during the at. so, there were reductions in both the central sbp and aix with central sbp becoming 15 mm hg lower than the peripheral sbp. i affirm that the patient has given the informed consent for publication of the case. (a) before association of vildagliptin and metformin, sys1 was 129 mm hg. sys2 and adjusted aix for a heart rate of 75 bpm (aix75) were 127 mm hg e 96%, respectively. sys2 (central) was only 2 mm hg lower than the peripheral systolic blood pressure and this difference should be about 15 to 20 mm hg or 15% lower than sys1. (b) after 3 months of vildagliptin and metformin association, sys1 was 116 mm hg, sys2 was 101 mm hg, and aix75 was 72%. both sys2 and aix presented reduction and sys2 had become 15 mm hg lower than the sys1. aix = augmentation index, aix75 = adjusted augmentation index for a heart rate of 75 bpm, sys1 = peripheral systolic blood pressure, sys2 = central systolic blood pressure. preventive strategies are important to reduce cardiovascular risk. an assessment and stratification of cardiovascular risk should be considered in order to identify individuals at higher risk of developing cardiovascular events. thus, the adoption of preventive and pharmacological strategies is important to delay possible cardiovascular complications. in recent years, several methods have been developed to predict cardiovascular risk, including the use of ultrasound to measure the carotid intima - media thickness (cimt) and the aortic pulse wave velocity, and computed tomography to identify and quantify calcification of coronary arteries, among others. in this case, the at of the radial artery was used to assess vascular disease. in young healthy individuals, the central sbp (aortic) should be between 15 and 20 mm hg lower than the peripheral sbp (brachial). before dpp-4 inhibitor use in this patient, the central sbp was only 2 mm hg lower than the peripheral sbp. after 3 months in use of vildagliptin, the difference between the central sbp and peripheral sbp increased to 15 mm hg. this finding might be explained by the effect of the drug on the arterial tree, that is, it may represent a reduction in arterial stiffness., aix also improved after dpp-4 inhibitor use, even though both were normal at baseline. aix is associated with cardiovascular risk as it identifies the presence or absence of chd, and thus it is also considered a marker of vascular stiffness. according to european society of hypertension guidelines, the evaluation of asymptomatic target organ damage (tod) is crucial in determining the cardiovascular risk in hypertensive individuals. among the tod to be assessed is vascular stiffness, which can predict cardiovascular mortality independently of the stratification scores of cardiovascular risk. the evaluation of central hemodynamic, including carotid - femoral pulse wave velocity, central bp, and aix, is important to determine the true cardiovascular risk. the guidelines state that the measurement of central hemodynamic parameters is of great interest to mechanistic analyses in pathophysiology, pharmacology, and therapeutics, and that the central bp represents the true load imposed on heart, brain, kidney, and large arteries instead of the brachial bp. thus, both central bp and aix present better predictive value for cardiovascular events and for the differential effect of antihypertensive drugs compared to the brachial bp. endothelial dysfunction is considered an early marker of vascular complications and a pathophysiological determinant of the atherogenesis that occurs in the early stages of chd. exposure to cardiovascular risk factors may trigger the atherosclerotic process that evolves with oxidative stress and nitric oxide (no) inactivation. endothelial dysfunction comprises a number of functional alterations such as impaired endothelium - dependent vasodilatation, impaired barrier function, and higher inflammatory and pro - coagulant activity. although pharmacotherapy based on the glp-1 system may provide beneficial effects to the endothelium (figure 2), there are no studies on the central bp. however, this study included an invasive method to assess endothelial function, which is not applicable in the clinical practice. sitagliptin, another dpp-4 inhibitor, demonstrated the same beneficial effects : an increase in endothelial progenitor cells by inhibiting the degradation of the chemokine stromal - derived factor 1-alpha and improved endothelial function in uncontrolled diabetic patients. some studies on this class of drugs have shown effects on no modulation. liraglutide, a new glp-1 receptor agonist, reduced the plasminogen activator inhibitor 1 and asymmetric dimethylarginine levels and, consequently, improved no availability. pathophysiological mechanisms that associate hyperglycemia, endothelial dysfunction, arterial stiffness, and cardiovascular disease. this figure explains how the hyperglycemia causes endothelial damage, which results in arterial stiffness and increased central bp. the glp-1 system provides beneficial effect on the endothelium in 2 ways, directly in the oxidative stress modulation (blocked arrow) or indirectly in the insulin production increase. the elevated central bp and aix may interfere in the endothelial dysfunction (dashed arrow), and contribute to the arterial stiffness. aix = augmentation index, bp = blood pressure, chd = coronary heart disease, cvd = cardiovascular disease, dpp-4 = dipeptidyl peptidase-4, glp-1 = glucagon - like peptide 1, tod = target organ damage. firstly, a vasodilator response to acetylcholine was observed in the vascular bed. in second place, vildagliptin is able to control the daily acute glucose fluctuations and delay the progression of atherosclerosis in dm. in this study, it was demonstrated that the cimt, a surrogate of carotid atherosclerosis, decreased 3 months after the use of both vildagliptin and sitagliptin. finally, glp-1 has been shown to exert anti - inflammatory effects on different tissues and to decrease daily oxidative stress parameters. thus, the decrease in the cimt might be mediated by improved vascular inflammation and endothelial dysfunction. in the present study, to better differentiate the effect of dpp-4 inhibitors on hemodynamic parameters (endothelial function, arterial stiffness, peripheral, and central sbp), it is important to consider the role played by changes in lifestyle on these benchmarks. some authors showed that individuals treated with dpp-4 inhibitors presented reductions in peripheral sbp independent of decreases in blood glucose and without reducing bmi. on the contrary, in obese patients with type 2 diabetes, treatment using dpp-4 inhibitors in combination with metformin was associated with improvements in glycemic control and a reduction in body weight. thus, it remains to be seen whether the reduction in bp with dpp-4 inhibitor treatment is related to the improvements in blood glucose and the drop in body weight or the effects of this therapeutic drug itself or both. recently, a study showed that weight loss was significantly and independently associated with central bp and brachial bp. however, the study population included a small number of hypertensive (35.8%) and diabetic (15.8%) patients. in morbidly obese dysglycemic subjects without hypertension, modest weight loss reduced arterial stiffness. another study demonstrated that 10.6% of weight loss did not influence the vascular stiffness in a nondiabetic population. in obese children and adolescents, moreover, low - fat versus low - carbohydrate diet in adults without dm demonstrated significant weight loss in both groups. however, arterial stiffness improved only in the group following the low - fat diet. in conclusion, with these data, the effect of weight loss on arterial stiffness is not clear, suggesting that more studies are necessary, including a study with a specific population (hypertensive and dm without coronary disease). in relationship to exercise, there is evidence that resistance training has an effect on the central bp ; however, the patient in this case did not do intense exercising. in respect to hba1c, some studies demonstrated weight loss in adults with dm managed by low - carbohydrate diet, but the hba1c level decreased only by 0.6% to 1.0%, while the weight loss was between 1.2 and 4.2 kg. these studies justified that weight loss participated in glycemic control, but it was not enough to decrease the hba1c level. furthermore, studies have shown solely reduction in peripheral bp with the use of dpp-4 inhibitors, without observing the effects on the central bp. so, we strongly believe that vildagliptin was the main responsible for the improvement in endothelial function, and peripheral and central sbp. anyway, as we know that one case report is not proof of the effect of dpp-4 inhibitor on central bp, a study that evaluates the endothelial function and glucose - independent beneficial cardiovascular effects of dpp-4 inhibitor is being carried out with this purpose. vilela - martin, md, phd, unpublished data, february 2015, https://clinicaltrials.gov/ct2/show/nct02145611?term=vildagliptin&rank=8). in conclusion, to the best of our knowledge this is the first report that suggests an effect of the dpp-4 inhibitor on arterial stiffness parameter (central bp) in a hypertensive and type 2 diabetic individual, using a noninvasive method for evaluating the central bp. other studies that evaluate the endothelial function and show glucose - independent beneficial cardiovascular effects of dpp-4 inhibitor are expected. | abstracthypertension and type 2 diabetes mellitus (dm) are among the main risk factors for the development of cardiovascular disease. pharmacotherapy for dm should not only improve blood glucose control, but also provide beneficial glucose - independent cardiovascular effects. the central systolic blood pressure (sbp) has become more important than the brachial sbp in the assessment of cardiovascular risk.this case report describes the effect of vildagliptin, a dipeptidyl peptidase-4 (dpp-4) inhibitor, on the central sbp in a 54-year - old woman with hypertension and dm. she was submitted to applanation tonometry (at) before and after vildagliptin association. at of the radial artery is a non - invasive method that indirectly assesses arterial stiffness by calculating the central sbp and the augmentation index (aix).after 3 months of follow - up using vildagliptin, central sbp and aix were improved. moreover, she presented better glycemic control.this case suggests an effect of dpp-4 inhibitor on arterial stiffness parameter (central sbp) in a hypertensive and diabetic patient, which shows a glucose - independent beneficial cardiovascular effect of this group of drugs. |
we analyzed the amino acid sequence of the receptor binding site of ha from the isolate a / jiangxi - donghu/346 - 1/2013 (h10-jd346 ; global initiative on sharing avian influenza data [gisaid, http://www.gisaid.org ] accession no. epi530526) from the first patient infected by influenza a(h10n8) virus. in addition, several human and avian influenza viruses (sequences from gisaid or the national center for biotechnology information website) and a recent harbor seal isolate (5) were compared with h10-jd346 (table). we observed that residues involved in receptor binding for h10 subtype influenza viruses suggest avian - like receptor specificity. however, we identified 2 amino acids in avian and human h10, t135 and s186, that are common in circulating human influenza viruses and were associated with changes in receptor binding in other avian influenza a virus subtypes (6,7). in accordance with this finding, vachieri. found substantial levels of binding of an avian h10 ha to sa2,6 that retained the ability to interact with sa2,3 (8). residues found in human h1 or h3 and in h10 hemagglutinin but not in other avian hemagglutinin sequences are shown in bold. given the role of receptor binding specificity of emerging influenza viruses, we analyzed the interaction of ha of the human h10-jd346 influenza a(h10n8) virus isolate in comparison with that of an avian h10n7 subtype virus. first, we used a solid - phase binding assay (9,10) and the following biotinylated glycans conjugated with a polyacrylamide (paa) support (provided by the consortium of functional glycomics [cfg ]) : neu5ac2,6gal14glcnac-paa (6 sln - paa) ; neu5ac26(gal14glcnac13)2-paa (6sdi - ln - paa) ; neu5ac2,3gal14glcnac-paa (3 sln - paa) ; neu5ac23(gal14glcnac13)2-paa (3sdi - ln - paa) ; and neu5ac23(gal14glcnac-sp)3-paa (3stri - ln - paa). we also analyzed recombinant hexahistidine - tagged has (11) from h10-jd346, an avian h10n7 subtype strain from north america (a / mallard / interior alaska/10bm01929/2010 ; h10-mallard), a human h3n2 subtype seasonal influenza a virus (a / panama/2007/1999 ; h3-p99), and an h5n1 subtype avian influenza virus from a fatal human case (a / vietnam/1203/2004 ; h5-viet). as expected, h3-p99 bound strongly to the sa2,6 tested, and h5 showed higher levels of binding to sa2,3 than to sa2,6 (figure 1, panel a). when we analyzed h10-mallard and h10-jd346, we found a similar binding profile, which is consistent with the presence of similar amino acids affecting the receptor binding specificity (table). although both h10 proteins had a prevalent avian - like binding profile, low levels of binding to sa2,6 were also observed. a) binding of recombinant hemagglutinins to glycans in a solid - phase binding assay. (human), h5-viet (avian origin isolated from a human case), and h10-mallard (avian) viruses were included in the analysis for comparison and as controls. values at the top right of the dot plots indicate percentage of cells expressing matrix protein 2 (m2). fsc, forward - scattered light ; fitc, fluorescein isothiocyanate. to confirm this data, we used a flow cytometry based assay and the same synthetic glycans (9,10). we infected mdck epithelial cells with h10-jd346 virus (6:2 re - assortant with the backbone of laboratory strain a / puerto rico/8/1934 [pr8 ], which was generated as described) (9,10) ; h10-mallard (wild - type) ; human isolate h3-p99 (wild - type) ; and h5-viet 6:2 (low pathogenicity reassortant with the backbone of pr8) (9,10) at a multiplicity of infection of 1. cells were harvested 24-h postinfection and incubated with antibody against matrix protein 2 (e10), which was detected by using an antibody against igg (alexa 647 antibody ; invitrogen, carlsbad, ca, usa) as a control of infection and with the sialyl - glycans (detected with streptavidin fluorescein isothiocyanate ; jackson laboratories, bar harbor, me, usa). we determined the percentage of infected cells in each sample and gated the infected population to determine the sa binding profile (figure 1, panel b). h3-p99 showed high levels of binding to sa2,6 and h5-viet bound more efficiently to sa2,3 than to sa2,6, which is similar to observations with recombinant has in the solid - phase binding assay. h10-mallard and h10-jd346 showed similar binding profiles with preferential binding for sa2,3 and binding to sa2,6 slightly higher than that for the negative control. analysis of receptor binding of h10-jd346 and of h10-mallard with 2 independent assays indicated that the h10 subtype influenza virus interacts slightly with human - like receptors and maintains preferential binding to avian - like receptors. consequently, these data suggest that h10 subtype influenza virus might have the ability to interact with the upper human respiratory tract, which is rich in sa2,6 (3). to test this hypothesis, we precomplexed h3-p99 and h10-jd346 with primary antibody (mouse anti - his tag) and secondary fluorescent antibody, then incubated the complex with 2 human tracheal samples (12). as expected, recombinant h10-jd346 ha also interacted with respiratory epithelia (figure 2), which suggested that the virus might be able to attach and replicate in the human upper respiratory tract. however, the 6:2 reassortant virus h10-jd346 virus showed markedly decreased replication compared with that of an h3n2 subtype virus (pr8 6:2 reassortant) in a human lung epithelial cell line (figure 3). interaction of hemagglutinin (ha) of h3-p99 (panels b and e) and h10-jd346 (panels c, f, and g) isolates of influenza a(h10n8) viruses with human trachea. scale bars indicate 25 m. replication of influenza a(h10n8) h10-jd346 virus in human epithelial cells. a549 cells (a human lung epithelial adenocarcinoma cell line) were infected at a multiplicity of infection of 0.1 with the h10-jd346 virus (6:2 re - assortant with the backbone of pr8) and another 6:2 re - assortant virus expressing hemagglutinin and neuraminidase genes from a human influenza a(h3n2) virus (a / wyoming/3/2003). cells were incubated at 37c in dulbecco minimal essential medium containing 0.3% bovine albumin (mp biomedicals, solon, oh, usa) and 1 g / ml of tolylsulfonyl phenylalanyl chloromethyl ketone treated trypsin (sigma, st. supernatants were collected at selected time points, and viral titers on mdck cells were determined by using a standard plaque assay. ha of novel influenza a(h10n8) virus interacts with sa2,3 and slightly with sa2,6, at levels similar to that for an avian h10 subtype ha, and binds to cells in the human upper respiratory tract. variations in the experimental settings and protocols (e.g., concentration of ha or glycans used) might account for these dissimilarities. an epidemic among seals caused by this virus subtype is currently ongoing in europe (5). a study by beare and webster showed that 50% of volunteers experimentally infected with influenza a(h10n7) virus shed virus (15), which our data suggests might be caused by initial attachment to the upper respiratory tract. immune responses were not detected in these volunteers, and mild, if any, symptoms developed, which indicated limited virus replication. the low incidence of h10 influenza virus indicates a limited pandemic potential of h10n7 and h10n8 viruses. therefore, further changes in receptor binding, as well as acquisition of genomic segments from other avian influenza virus strains through co - infection, would be required to increase fitness and transmissibility in mammals. isolate h10-jd346 amino acid sequence had a mixture of e and k in position 627 of basic polymerase protein 2 ; the k627 mutation is associated with mammal adaptation (1). this finding highlights the need for an efficient surveillance network to track and identify possible changes, as well as extensive research to identify them and understand their functional consequences. | three cases of influenza a(h10n8) virus infection in humans have been reported ; 2 of these infected persons died. characterization of the receptor binding pattern of h10 hemagglutinin from avian and human isolates showed that both interact weakly with human - like receptors and maintain strong affinity for avian - like receptors. |
balanitis xerotica obliterans (bxo) is a common penile disease, first described in 1928 by stuhmer. it has been classified as a male variant of lichen sclerosis by the international society for the study of vulvovaginal disease and is a chronic inflammatory process. whilst the exact aetiology is still poorly understood it is thought that it could be genetically determined and there is evidence to suggest a higher incidence of autoimmune diseases amongst patients with bxo. the disease usually presents initially on the glans penis or prepuce, affecting the foreskin, meatus and distal urethra either individually or in combination. left untreated it has been reported to affect the entire urethra, penile skin and scrotum. bxo is most commonly found in patients aged 30 - 60 years but there have been increasing reports of the disease in the paediatric population and it is now known to be the most common cause of pathological phimosis in boys. the clinical progression of bxo can vary ; it can present acutely with erythema and discharge leading to early blistering and fissuring or it can follow a more chronic course, presenting initially with grey - white skin discolouration leading to complications at a much later stage. in either case, patients can experience ulceration of the glans, fissuring, phimosis, meatal stenosis and urethral strictures in untreated disease leading to problems with urinary and sexual function. on many occasions, there have been cases reported of scrotal fistula formation, renal impairment and a documented association between chronic bxo and an increased risk of penile squamous cell carcinoma. the differential diagnoses include lichen planus, scleroderma, leukoplakia, vitiligo and erythroplasia of queyrat. the histological features are characteristic, showing hyperkeratosis with atrophic epidermis, thinned rete pegs, vacuolar degeneration of basal layer, washed out appearance of the papillary and reticular dermis, amorphous band by dermal collagen at the dermal - epithelial junction and chronic inflammatory infiltrate deep to the band. topical steroid creams are the mainstay of medical treatment used in early - stage disease but there is limited evidence to support their use in recurrent, severe or advanced disease. but for patients with bxo involving the meatus or urethra the options include meatoplasty, urethrotomy, urethral dilatation or a more definitive procedure such as urethroplasty using buccal or bladder mucosal grafts and or excision of bxo with skin grafting if involving the glans, coronal sulcus and adjacent shaft of penis. in our unit the senior authors have an established hypospadias practice including adult salvage surgery and additionally offer male genital reconstruction for patients with advanced bxo. all patients with bxo referred to the plastic surgery department at our unit (tertiary referral centre) between 2005 and 2009 were included in the study. data was collected retrospectively using a data collection sheet to collate information from patient notes. referring specialty, the anatomical location of the bxo and duration of symptoms were noted. previous management including surgical procedures was documented and any change in urinary or sexual function secondary to the disease process was recorded. twenty - three patients aged between four and 78 (mean age 38) [figure 1 ] were referred from six different specialties. forty - eight percent of referrals were from urology, 17% were from general practitioners (gps) and 13% were from dermatology. the remaining patients were referred from the general surgery, genitourinary medicine and other plastic surgery units. forty - seven percent of patients were seen at our unit within two years of being diagnosed with bxo but 21% of patients were not referred for over five years and two patients were suffering from bxo - related problems for over ten years. in the group of 23 there were seven patients who had bxo affecting between three and five areas of their genitalia, indicating severe progressive disease. of the four that had had previous surgery prior to referral to our unit, all had either release of adhesions or urethral / meatal dilatation. reconstructive surgery with excision of the affected area and skin grafting or urethroplasty was performed for these patients and they are still being followed in the clinic. to date there is no recurrence of the disease and the patients have reported subjective improvement in their urinary and sexual function from before surgery. a patient in our study who had bxo affecting his meatus and urethra had undergone two optical urethrotomies and four urethral dilatations over a period of 12 years [figure 2 ]. due to the spread of the disease he needed to perform intermittent self - catheterisation twice a week to maintain a reasonable urinary flow for nearly ten years. we performed distal urethrotomy of the dense stricture to allow urethroscopy which also showed skip lesions of bxo in the posterior urethra. the patient underwent excision of the distal stricture and two - stage urethral reconstruction using a buccal mucosa graft [figure 3 ]. subsequently he was able to pass urine normally without the need for the self - catheterisation. at two years post procedure chronic bxo urethral stricture pre - op (a - d) and cystourethrogram (e) post - op i stage -stricture excised (a - d) grafted using buccal mucosa & ii stage reconstruction (a1-d4) in order to assess the progression of the disease, we recorded the anatomical location of the affected area. patients were recorded as having bxo affecting the foreskin, glans, meatus, penile shaft, urethra and scrotum or any combination of these. forty percent of patients had bxo confined to the foreskin and glans and a further 14% had disease affecting the foreskin only. thirteen percent of patients had disease affecting three areas, a further 13% had disease affecting four areas and one patient had bxo involving the foreskin, glans, meatus, urethra and scrotum. forty - three percent of patients had surgical intervention prior to referral and 60% of those had two or more procedures. these included optical urethrotomy, circumcision, urethral dilatation, hypospadias repair, meatoplasty and debridement / release of penile skin [figure 4 ]. thirty percent had previous medical treatment in the form of steroid creams, anti - fungal cream, antibiotics or self - catheterisation. sixty - one percent of patients had previously undergone circumcision (a proportion of these were unrelated to the diagnosis of bxo). previous surgical treatment forty - seven percent of patients had alteration of their urinary function due to the disease. forty - eight percent had problems with sexual function and described fissuring, painful intercourse, bleeding, erectile dysfunction and discharge. fifty - two percent of the procedures performed in our department were examination under anaesthesia (eua) and circumcision [figure 5 ]. this correlates with the proportion of patients diagnosed with bxo affecting only the glans or foreskin. however, four patients underwent a two - stage urethroplasty with buccal mucosal reconstruction, two patients had urethral tubularisations and one had an optical urethrotomy. the remainder had excision of the affected skin and grafting [an example shown in figure 6 ] or meatal reconstruction. early results showed that 100% of these patients had a subjective improvement in urinary or sexual function following plastic surgery input. one hundred percent patients had no recurrence of the disease after treatment in our unit although 13% had bxo still visible but not advancing. patients were followed up for an average of two years and five months prior to discharge. bxo involving glans and corona (a3-d3) excised and resurfaced with split skin graft (a4-d4) when looking at the effectiveness of medical therapy for the treatment of bxo our results show limited success. many cases eventually required surgical treatment. of the seven patients treated with steroid creams, anti - fungal or antibiotics three had disease confined to the foreskin and glans but with evidence of adhesions or scarring. the remaining four patients had advanced disease that had spread to the penile shaft or scrotum. a literature review conducted by pugliese., in 2008 concluded that there was no guidance on the duration of treatment with a steroid cream or the type of steroid to use and it described limited long - term benefit and disease recurrence once treatment ceased. this was supported by a study looking at a paediatric population using steroid cream which showed resolution in patients with clinically mild bxo that was limited to the prepuce but no reported benefit in those with more severe disease. another paediatric study has shown a recurrence of symptoms following cessation of the steroid treatment despite initial disease regression. for patients with disease confined to their glans or foreskin, circumcision offers cure by eliminating the moist urine - rich environment in which bxo can progress. in a case series of 287 patients with bxo limited to the foreskin or glans treated by circumcision, 92% had cessation of symptoms and no further advancement of the disease following surgery. our results support this finding and these patients, who had minimal urinary and sexual function symptoms prior to surgery, were discharged from clinic at an early stage. for patients with urethral or meatal involvement surgical intervention is required. in the case of meatal stenosis or navicular fossa strictures, ventral meatotomy, dorsal meatoplasty or excisional meatoplasty urethral strictures have a high associated morbidity, causing fibrosis of the corpora spongiosum and urinary outflow obstruction, which in turn can lead to high pressures in the upper urinary tract. this method requires more specialised surgical training and a longer hospital stay than conventional methods such as urethral dilatation or urethrotomy. for these reasons, simple procedures are often chosen in preference to urethroplasty but they have limited success rates urethral dilatation has never been considered to be curative but is a simple procedure that can be offered under a local anaesthetic in a day case setting. in 1997, steenkamp., performed a study directly comparing urethral dilatation to urethrotomy for the treatment of urethral strictures. no statistical difference was found between these two procedures in terms of stricture recurrence rate but both procedures had poor outcomes if used for the treatment of strictures over 4 cm in length. a recent cochrane review looked at the evidence comparing urethral dilatation, urethrotomy and urethroplasty for the treatment of urethral strictures. whilst there was not enough current evidence to compare dilatation and urethrotomy to urethroplasty, there was no difference found between dilatation and urethrotomy in terms of cure rate. a study directly comparing urethral dilation and urethrotomy found there was no long - term benefit in a second procedure (either dilatation or urethrotomy) for early stricture recurrence. if urethroplasty is chosen as a treatment method, options for graft donor site include local genital skin or buccal or lingual mucosa. trivedi., had limited success with local grafts and favoured lingual over buccal mucosa due to easier graft harvesting and lower rates of donor site morbidity. pugliese., report high rates of disease recurrence in genital skin grafts and advocate the use of buccal grafts in either a one - stage or a two - stage reconstruction. depasquale., reported 90% stricture recurrence rate in a long - term follow - up of 42 cases of bxo urethral strictures excised and reconstructed using skin, many requiring reoperations using mucosa subsequently. there were no recurrences reported in their series of bxo urethral reconstructions carried out using buccal or bladder mucosa. although our case series is small we think our results show the importance of early recognition of unresolved, progressive and recurrent bxo cases. steroid creams have been shown to limit the progression of the disease but do not offer a cure in the majority of cases. the progression of the bxo disease gets arrested following circumcision by removing the urine - rich environment and patients with meatal or urethral disease are most likely to require excision and/or reconstruction for a long - lasting cure. suitable cases should be referred to specialised units for further assessment and surgical management by excision and/or reconstruction for a disease that is prevalent in the male population. | background : balanitis xerotica obliterans (bxo) is a chronic, often progressive disease, which can lead to phimosis and urethral stenosis, affecting both urinary and sexual function. steroid creams are usually the first - line treatment but have a limited role and surgical intervention is frequently necessary. conservative surgical procedures (circumcision) are often preferred in the first instance with the premise that recurrence of disease will require a more definitive reconstruction. this study looked at patients with pathologically proven bxo referred to the plastic surgery unit at james cook university hospital between 2005 and 2009. the aim was to look at their management in the past and subsequent management by us. we also looked at whether early referral of progressive and recurrent bxo patients to reconstructive surgery could have prevented unnecessary delay in resolving symptoms at an earlier stage.materials and methods : data was collected retrospectively and information regarding the exact anatomical location affected, the extent of the disease, the referring specialty and any previous surgical interventions was obtained. alterations in urinary and sexual function and relief of symptoms following reconstructive surgery were analysed.results:of the 23 patients in the study, 43% had previous surgery and 60% of those had undergone two or more procedures. twenty - one percent of patients had a history of bxo for over five years. forty - seven percent of patients had alteration in their urinary function and 48% alteration in their sexual function due to the disease, prior to referral. early results showed remarkable improvement in urinary and sexual function following reconstructive surgery in this group.conclusions:steroid creams have been shown to limit the progression of the disease but do not offer a cure in the majority of cases. circumcision can be a curative procedure in early disease. although there is conflicting evidence for treatment of recurring urethral strictures, repeated urethrotomy or urethral dilatation has poor long - term outcome. in patients with recurrent disease and associated complications we propose early referral to a plastic surgeon with genitourinary interest or reconstructive urologist for definitive treatment. |
human infection by the lung fluke paragonimus westermani is endemic in parts of africa, asia, and south america. transmission of the parasite to humans primarily occurs through the consumption of raw or undercooked crabs and cray fish. patients present with a variety of clinical and radiological findings, frequently mimicking those of tuberculosis (tb) and lung cancer. the first indigenous case of human paragonimiasis, in india, was described by singh. in 1981, in manipur. paragonimiasis cases have been detected every year in manipur, but only a few have been reported. this study has been carried out with an aim to study the demographic characteristics of patients with pulmonary paragonimiasis to analyze their clinical features associated complications and discuss their optimal management. this study has been carried out with an aim to study the demographic characteristics of patients with pulmonary paragonimiasis to analyze their clinical features associated complications and discuss their optimal management. the study was an institutional based cross - sectional study conducted at the department of respiratory medicine, regional institute of medical sciences, imphal, manipur, from january 2013 to december 2015. eleven cases were detected from patients who were coming from different areas of manipur and attending the outpatient department and/or were admitted in the indoor wards of the department of respiratory medicine during the study period. patient with recurrent respiratory symptoms such as cough, chest pain, breathlessness, hemoptysis, fever, pleural effusion, peripheral eosinophilia, and pleural fluid eosinophilia, who were above 18 years were included in this study, whereas those patients who were unwilling to participate or patients whose peripheral eosinophilic count and absolute eosinophilic count was found to be in normal limit were excluded from this study as suspicion of parasitic disease is aroused by the peripheral blood eosinophilia who resides or travelled to endemic area. each individual enrolled in the study underwent a detailed history, clinical examination, and laboratory examination designed for the study. the study was approved by the institutional review board, and all participants gave written informed consent. in all the participating patients, routine blood investigations including absolute eosinophil count were carried out. chest x - ray pa view, sputum for acid - fast bacilli (afb) smear and culture, sputum smear for paragonimus eggs, and serological test for paragonimiasis (elisa) were done. diagnostic pleural tapping was done in the case of patients with pleural effusion, and fluid was sent for routine analysis including gram stain, afb smear and culture, and eggs for paragonimus. table 1 show, out of these 11 cases, 05 (45.5%) were males and 06 (54.5%) were females. mean age (sd) in years for cases was 38.1 (16.96), among them 7 were from hilly areas and 4 from the valley, and all cases had a history of fresh water crab intake either raw or pickled form. demographic features of cases and controls figure 1 shows different presentation of pulmonary paragonimiasis. all patients had respiratory symptoms. among respiratory symptoms maximum number (7 patients) were presented with unilateral pleural effusion followed by hemoptysis (2 patients). presentation of paragonimiasis figure 2 shows laboratory methods used to suspect and diagnose pulmonary paragonimiasis. all the eleven cases had peripheral eosinophilia and significantly higher absolute eosinophil count. in all the cases of effusion, one patient had paragonimus ova in sputum smear, [figure 3 ] and one patient had paragonimus eggs in pleural fluid. laboratory methods used to diagnose pulmonary paragonimiasis eggs of paragonimus westermani were found in wet mount sputum in one of the patients all patients received tablet praziquantal in the dose of 25 mg / kg body weight, administered orally 3 times a day after meals for three consecutive days without any appreciable side effects and were followed up for 89 weeks and declared cured. pleural fluid aspiration, intercostal chest tube drain for hydropneumothorax and pneumothorax, and symptomatic treatment were given as required. p. westermani, heterotremous, and paragonimus skrjabini are the principle species causing human infection in southeast asian countries. of these, p. westermani is the most common and wide spread. in india, manipur is one of those rare areas of the world where paragonimus heterotremous is prevalent most. this species may be one of the important cause of paragonimiasis in animals and humans in manipur. humans typically acquire the disease by ingesting raw or undercooked crabs or cray fish or by drinking water contaminated by them. as a result, the disease tends to occur in families because of common dietary exposure. radiologically, may be presented as consolidation, pleural effusion, and other nonspecific abnormalities. these pulmonary changes result from chronic inflammation in the areas surrounding the worms. in this study, we have put in efforts to study demographic characteristics and analysis of paragonimiasis infection in manipur. patients from the endemic regions are presenting with chest complaints, chest x - ray changes in the form of consolidation, pleural effusion, and other nonspecific signs with eosinophilia were suspected to have paragonimiasis. it was noted that there is no much gender propensity for paragonimiasis which is contrary to a study done by jeon., who found pulmonary paragonimiasis is more common in males. this contrary can be explained by the fact that transmission is by ingestion of either raw or pickled crabs or cray fish and hence, both the genders are equally exposed. in our study, the mean age of the affected population was 38.1 16.96, whereas mukae. we observed that prevalence was more common in patients from hilly areas than valleys which might be due to easy accessibility to fresh water crabs in streams. of note, three patients were erroneously treated with antitubercular drugs without any relief which is in line with a study done in korea. this error in diagnosis perhaps applies mostly to patients who have pleural effusion in addition to parenchymal disease. therefore, a detailed clinical history of illness including dietary habit of consumption of crabs and laboratory investigation such as complete blood count, absolute eosinophil count, sputum and pleural fluid examinations for eosinophils, paragonimus eggs, and serodiagnosis are essentially important in all cases with respiratory symptoms in endemic areas and immigrants from endemic regions to avoid misdiagnosis. all the study subjects had a history of crab intake and presented with respiratory symptoms such as chest pain, breathlessness, and cough with expectoration. two patients presented with complications such as pneumothorax and hydropneumothorax, and seven patients had one sided pleural effusion. flukes often penetrate the diaphragm and pleura ; hence the pleural effusion, pneumothorax, and hydropneumothorax. a bronchial artery in the vicinity of the cyst undergoes hypertrophy and results in hemoptysis, which was observed in two patients in this study. these clinical features are similar to a study done in a tertiary referral center, korea. another biologic characteristic of migrating worm infections, particularly in host tissues such as the lungs, is the association with eosinophilia in the peripheral blood and tissue, which was seen in all the study subjects and eight patients had pleural fluid eosinophilia. nine patients were diagnosed by serological test, one patient had paragonimus ova in sputum smear, and one patient had paragonimus eggs in pleural fluid. a study by slemenda. stated if the clinical history is suspicious and eggs laden sputum can not be demonstrated, the humoral immune response, which is considered supplementary tool, can be quantified through enzyme immunoassay and elisa is found to be highly sensitive and specific for paragonimiasis. clinical features of recently diagnosed pulmonary paragonimiasis show that patients presented with a variety of clinical and radiological findings, frequently mimicking those of tb, parapneumonic effusion, and lung cancer. on the other, we need to rule out pulmonary koch, most common infection in our country and carcinoma lung which constitutes an important differential diagnosis of pulmonary paragonimiasis. other rare cause of eosinophilia with chest symptoms includes round worm infestations, dirofilariasis, and hydatid cyst which has to be kept in mind in endemic areas. all study subjects had excellent clinical responses to praziquantal given at a dose of 25 mg / kg given orally 3 times daily for 3 consecutive days with improved symptoms and resolution of eosinophilia. it is in agreement with the earlier reports where cure rate is almost 100%, and very few cases with heavy infection needed a second course of treatment. there is a need to generate awareness among the clinicians and public regarding paragonimiasis and to consider it in differential diagnosis of tb and carcinoma lung. public health education messages should warn people not to eat uncooked crab or cray fish. physicians should consider the possibility of paragonimiasis among patients who present with chest complaints with eosinophilia from the endemic regions. | background : human infection by the lung fluke paragonimus westermani is widely distributed in africa, asia, and south america. transmission of the parasite to humans primarily occurs through the consumption of raw or undercooked crabs. clinical features of recently diagnosed pulmonary paragonimiasis show that patients present with a variety of clinical and radiological findings, frequently mimics tuberculosis and lung cancer.methods:here in this study, we report a cross - sectional study of pulmonary paragonimiasis in our institute over a period of two year.results:it was observed that out of eleven cases, prevalence of paragonimiasis was almost equal among both the genders, with a mean age of 38.1 16.96, affecting people from hills. three patients were erroneously treated with antitubercular drugs without any relief. the association with eosinophilia in the peripheral blood and tissue[16 ] was seen in all the study subjects and majority patients had pleural fluid eosinophilia. patients were diagnosed by serological test, paragonimus ova in sputum smear and pleural fluid. all study subjects had excellent clinical responses to praziquantel given at dose of 25 mg / kg given orally 3 times daily for 3 consecutive days.conclusions:there is a need to generate awareness among the clinicians and public regarding paragonimiasis and to consider it in differential diagnosis of tb and carcinoma lung. physicians should consider the possibility of paragonimiasis among patients who present with chest complaints with eosinophilia from the endemic regions. |
pancreatic resection is a surgical procedure associated with significant morbidity and mortality even at specialised high - volume centres [13 ]. although in recent years refinements in surgical technique and perioperative management have led to a reduction in perioperative mortality, the incidence of postoperative complications (including intra - abdominal abscesses and leakages [49 ], biliary complications [1014 ] and vascular complications [1518 ]) still remains high. moreover, in case of complications, surgical re - operation is associated with a high mortality rate [13 ]. in a large series of 650 patients, yeo. reported an overall mortality of 1.4 % and a morbidity of 41 %, with a mean length of hospital stay of 13 days. they reported re - operation in 26/650 patients (4 %) and identified the absence of reoperation as an independent predictor of prolonged survival. interventional radiology (ir) provides a minimally invasive alternative for managing post - surgical complications [19, 20 ]. several different ir procedures, such as percutaneous drainage, aspiration of abscesses or fluid collections [4, 5 ], percutaneous transhepatic biliary drainage, and arterial embolisation [2123 ] have been introduced in clinical practice to treat post - surgical complications. ir procedures are an alternative approach to manage post - surgical complications less invasive than surgical re - intervention, and may lead to a reduction in hospital stay and re - operation rate [10, 11 ]. in the present pictorial review, we offer an overview on the ir procedures that can be performed to treat different types of complications after pancreatic resection. intra - abdominal collections and abscesses represent the most common complication following pancreatic surgery [13 ]. once an intra - abdominal collection is identified, in most cases it is possible to place a percutaneous drainage under image guidance. when the collection is well visible using ultrasound (us), us - guided percutaneous drainage placement is generally the preferred choice, as us is widely available, easy to handle and allows for real - time monitoring of the drainage placement, being also free from ionising radiation. when the collection is located deep in the abdomen and is not well seen at us, computed tomography (ct) generally offers good anatomical definition to guide the safe placement of a percutaneous drainage. drainage placement can be performed using the trocar or seldinger technique. in the trocar technique, the trocar technique provides a fast deployment of the drainage that can be extremely helpful in critically ill or agitated patients. the seldinger technique implies multiple steps : the collection is punctured with a small calibre needle, different calibre guidewires are inserted and the drainage is then advanced up to the collection over the guidewire. the seldinger technique is particularly helpful when there is a small window to reach the collection, as typically happens when a retroperitoneal collection has to be drained through an anterior approach. the main disadvantage of this technique is that it may require considerably longer time than the trocar technique. the correct location of the needle or drainage can be confirmed by aspiration of a small amount of material. furthermore, a small amount of iodinated contrast may be injected through the catheter to identify the presence of an underlying fistula. in a series of 373 subjects who underwent pancreaticoduodenectomy reported by zink. they report an immediate technical and overall success rate of 97.6 and 79.6 %, respectively. a case of a patient with fluid collection after pancreaticoduodenectomy successfully managed with percutaneous ct guided drainage b the fluid collection (asterisks) is punctured with a small needle under ct guidance. c a percutaneous drainage (arrow) is inserted into the collection (asterisks) using the seldinger technique. d at the end of the treatment complete resolution of the collection is obtained use of a percutaneous drainage to treat a post - pancreaticoduodenectomy fluid collection. a ct scan shows post - pancreaticoduodenectomy retroperitoneal fluid collection (asterisks). b the fluid collection (asterisks) is punctured with a small needle under ct guidance. c a percutaneous drainage (arrow) is inserted into the collection (asterisks) using the seldinger technique. in patients treated by pancreaticoduodenectomy with roux - en - y bilio - enteric reconstruction, endoscopical access to the biliary tree is not feasible. thus, in this kind of patient, a percutaneous transhepatic route is the only approach to the biliary system in case of biliary complications. the access to the biliary system is obtained by puncturing a peripheral bile duct under us and/or fluoroscopic guidance. they have been reported in about 34 % of cases after pancreatic surgery [13 ]. these complications are often associated with others, in particular with pancreatic fistula and fluid collections. in patients who develop such complication after surgery, percutaneous transhepatic biliary drainage by allowing for a bile diversion from the site of the fistula has been proven to be feasible and effective in the majority of cases [6, 20, 21 ]. the positioning of an occlusion balloon to obstruct the biliary duct above the site of the fistula, by allowing for complete external drainage of the bile, may represent a valuable option to treat post - surgical biliary leaks [7, 10 ]. a different and more recent technique is to use a covered stent that can close the bile leak and subsequently be retrieved percutaneously. used this approach successfully in 11 patients with postoperative bile leak, with no recurrence in the 1-year follow - up. a case of a patient with post - surgical biliary leak successfully treated with percutaneous transhepatic biliary drainage is shown in fig. 2use of a percutaneous transhepatic biliary drainage to treat a post - surgical biliary leak. a percutaneous colangiography demonstrates a biliary leak (arrow) and a biliary drainage (white arrows) is inserted via segment iii left lobe approach ; rbt right biliary tree, lbt left biliary tree, sb small bowel. b final result with complete healing of the leak and absence of contrast leakage ; rbt right biliary tree, lbt left biliary tree, sb bowel use of a percutaneous transhepatic biliary drainage to treat a post - surgical biliary leak. a percutaneous colangiography demonstrates a biliary leak (arrow) and a biliary drainage (white arrows) is inserted via segment iii left lobe approach ; rbt right biliary tree, lbt left biliary tree, sb small bowel. b final result with complete healing of the leak and absence of contrast leakage ; rbt right biliary tree, lbt left biliary tree, sb bowel after bilio - pancreatic surgery, stricture of a biliary duct may represent a serious complication,. surgical re - intervention is associated with morbidity and mortality rates as high as 28 and 2.6 % respectively. percutaneous treatments represent an effective alternative to surgery in the treatment of such complication [2729 ]. to achieve resolution of the stenosis, subsequent larger biliary drainage catheter may be inserted and left in place and balloon dilation can be performed. however, recurrence of stenosis may occur in up to 2958 % of cases [2729 ], and multiple treatment sessions may be required. stents are rarely used in the treatment of benign strictures, as they have to be removed after a period because the tube itself may stimulate inflammatory reaction, fibrosis and stone formation. a novel option may be represented by the use of biodegradable biliary stents, which may improve the long - term patency rate, without requiring a subsequent procedure for removal. a case of a patient with a post - surgical biliary stricture successfully treated with balloon dilation and placement of a biodegradable biliary stent is shown in fig. 3percutaneous treatment of a benign stricture of the common bile duct by a bioabsorbable biliary stent. radiopaque contrast agent can be detected in the bowel (b) ; asterisks dilated bile ducts. the stent is radiolucent, but two platinum, radiopaque markers can be seen (black arrowheads) ; asterisks dilated bile ducts, b bowel. d the stent is fully expanded and radiopaque bile can be seen flowing through the patent common bile duct (white arrowheads) ; black arrows radiopaque stent markers ; b bowel. e us follow - up at 3 months demonstrating good visibility of the stent (arrowheads) that was correctly expanded, and no dilation of the intrahepatic biliary ducts ; l liver percutaneous treatment of a benign stricture of the common bile duct by a bioabsorbable biliary stent. radiopaque contrast agent can be detected in the bowel (b) ; asterisks dilated bile ducts. the stent is radiolucent, but two platinum, radiopaque markers can be seen (black arrowheads) ; asterisks dilated bile ducts, b bowel. d the stent is fully expanded and radiopaque bile can be seen flowing through the patent common bile duct (white arrowheads) ; black arrows radiopaque stent markers ; b bowel. e us follow - up at 3 months demonstrating good visibility of the stent (arrowheads) that was correctly expanded, and no dilation of the intrahepatic biliary ducts ; l liver postoperative intra - abdominal arterial haemorrhage is still one of the most serious complications, with a reported incidence between 1.5 and 15 %, and a reported mortality rate of 2050 % [1517 ]. early haemorrhage requires immediate laparotomy, as it is generally caused by a technical failure or underlying coagulopathy, while the most appropriate management of delayed haemorrhage still remains controversial. in haemodynamically stable patients, ct is crucial to address the suspicion of a delayed haemorrhage and is extremely useful prior to angiography as it may avoid it or guide it. in unstable patients, direct visceral angiography has been suggested as the best method to elucidate the site of bleeding, with the advantage of sparing time for a subsequent immediate intra - arterial treatment. transcatheter arterial embolisation has been reported to be safe and effective, with a reported success rate of 50100 %, gaining acceptance for the treatment of intra - abdominal bleeding [1517 ]. once the site of bleeding has been identified, several different techniques may be used to stop bleeding and achieve haemostasis. in case of terminal vascularisation, a proximal embolisation of the bleeding vessel may be enough to achieve the haemostasis, while in the presence of collaterals, it is crucial to embolise both the inflow and outflow vessels in order to avoid re - bleeding (isolation technique). different materials are nowadays available to obtain vascular occlusion, and have to be chosen according to the desired type of vascular occlusion (transient or permanent). transient embolisation, generally required due to a traumatic haemorrhage, is reached by resorbable materials, which allows for restoring the blood flow in a variable window of time (inter alia : autologous blood clot, gelatine or fibrin sponge). the main advantage of such materials is to avoid definitive occlusion of the treated vessel. however, a non - negligible risk of re - bleeding has to be considered once the material has been absorbed. permanent embolisation is reached using non - resorbable materials (polyvynilic alcohol, bucrilate, metallic coils or detachable balloons) that induce a permanent vessel occlusion. at the present, an ideal material does not exist, thus the choice of the most appropriate embolic material and technique for embolisation, crucial to minimise failure and complications, requires the presence of a ir team with high experience and the availability of several different materials. stent grafting of the artery at the site of bleeding has been proposed as an alternative or in addition to embolisation, with the advantage of maintaining the patency of the end organ, thus minimising the risk of ischaemia deriving from embolisation. a recent meta - analyisis comparing laparotomy and transarterial embolisation for the management of delayed postoperative haemorrhage found a reduction in mortality (43 % vs 20 %) and morbidity (77 % vs 35 %) in the ir group, even if not reaching the statistical significance. authors conclude that the appropriate treatment pathway for late haemorrhage ultimately will be decided by the clinical status of the patient and the institution preference. a case of transcatheter arterial embolisation for a post - surgical haemorrhage 4arterial embolisation of a post - surgical haemorrhage. a ct scan showing contrast extravasation (arrow) from the celiac trunk at the level of the bifurcation between hepatic and splenic artery ; b angiographic appearance of the active bleeding with contrast extravasation (arrows) ; asterisk celiac trunk, black arrowhead splenic artery, white arrowhead hepatic artery. c angiography after embolisation with coils (arrows) demonstrating absence of contrast extravasation at the level of previous bleeding. d ct scan at 2 years, demonstrating absence of contrast extravasation at the level of previous bleeding and preserved patency of proper hepatic artery (white arrow), even in the presence of part of a coil in its lumen (arrowhead) ; black arrow clustered metallic coils in the focus of arterial lesion properly embolised arterial embolisation of a post - surgical haemorrhage. a ct scan showing contrast extravasation (arrow) from the celiac trunk at the level of the bifurcation between hepatic and splenic artery ; v inferior vena cava, a abdominal aorta. b angiographic appearance of the active bleeding with contrast extravasation (arrows) ; asterisk celiac trunk, black arrowhead splenic artery, white arrowhead hepatic artery. c angiography after embolisation with coils (arrows) demonstrating absence of contrast extravasation at the level of previous bleeding. d ct scan at 2 years, demonstrating absence of contrast extravasation at the level of previous bleeding and preserved patency of proper hepatic artery (white arrow), even in the presence of part of a coil in its lumen (arrowhead) ; black arrow clustered metallic coils in the focus of arterial lesion properly embolised in some cases, post - surgical complications may involve the portal and mesenteric veins, which may develop stenosis or thrombosis after surgical treatment. moreover, with the recent advancement of vascular reconstruction with polytetrafluoroethylene graft, this occurrence may happen more frequently in the future. percutaneous endovascular treatment, such as transjugular portosystemic shunt, direct and indirect thrombolysis, stenting and mechanical thrombectomy, described mainly in liver - transplant patients, may represent a valuable option in the management of these conditions after pancreatic surgery [2, 5, 18 ]. the access to the portal system may be achieved through a transhepatic route, with the direct image guided puncture of a peripheral portal branch, or through a transjugular approach, by puncturing the portal system from the hepatic veins. transhepatic access is generally easier than transjugular access and represents the first choice strategy in patients with normal coagulation parameters. in patients with thrombosis of the portal or mesenteric vein, in which anticoagulation treatment has been undertaken, the best choice is represented by the transjugular approach, in order to minimise the risk of peritoneal haemorrhage correlated with direct liver puncture. once the access to the portal system has been achieved, it is possible to perform balloon dilation and stenting of post - surgical strictures using the several different commercially available devices. in case of thrombosis, direct trombo - aspiration through a catheter or infusion of trombolitic agents has been reported as a feasible and effective treatment. a case of post - surgical mesenteric vein stenosis and thrombosis treated percutaneously 5treatment of a patient with postoperative mesenteric vein stenosis and thrombosis by percutaneous transhepatic stenting, thromboaspiration, and thrombolysis through a transjugular approach (the case has been partially previously reported). a maximum intensity projection reconstruction of abdominal mdct shows surgical vascular graft (black arrow) at the level of the superior mesenteric vein and ascitic fluid (asterisks) b percutaneous transhepatic angiography demonstrates stenosis at the level of proximal (black arrow) and distal (white arrow) anastomoses of the ptfe graft. c angiography after stent placement (black arrow proximal stent, white arrow distal stent) demonstrating resolution of the stenosis. d mdct mip reconstruction and e axial image showing intra - stent thrombosis (white arrow) and ascitic fluid (asterisks). h complete resolution and calibre restoration after direct thrombolysis with rt - pa treatment of a patient with postoperative mesenteric vein stenosis and thrombosis by percutaneous transhepatic stenting, thromboaspiration, and thrombolysis through a transjugular approach (the case has been partially previously reported). a maximum intensity projection reconstruction of abdominal mdct shows surgical vascular graft (black arrow) at the level of the superior mesenteric vein and ascitic fluid (asterisks) b percutaneous transhepatic angiography demonstrates stenosis at the level of proximal (black arrow) and distal (white arrow) anastomoses of the ptfe graft. c angiography after stent placement (black arrow proximal stent, white arrow distal stent) demonstrating resolution of the stenosis. d mdct mip reconstruction and e axial image showing intra - stent thrombosis (white arrow) and ascitic fluid (asterisks). fistulas are the most common complication following pancreatic surgery after presence of fluid collections [13 ]. the most frequent type is pancreatic fistula, followed by enteric and biliary fistulas [13 ]. this kind of complication is frequently associated with others, in particular the presence of an intra - abdominal fluid collection. recent reports highlighted how this kind of complication can be successfully managed without surgery in over 90 % of patients. in the non - operative management of such complications, ir plays a crucial role. in presence of a fluid collection, a percutaneously placed drainage may be enough to treat the collection, and in several cases to allow for the spontaneous closure of the fistula [4, 5 ]. if the main component of a fistula is biliary material, the transhepatic insertion of a biliary drainage, by diverting the bile from the site of the fistula, may be enough to determine the fistula closure. in cases with persisting biliary leak, the placement of an occlusion balloon above the fistula, by interrupting completely the bile flow towards the site of the fistula, has been reported as an effective tool [710 ]. some authors reported the direct embolisation of the site of the fistula as a feasible and effective procedure. this can be done through a previously placed surgical drainage, through an image - guided percutaneously placed drainage, or even through a transhepatic approach. once the site of the fistula has been reached, several different materials can be used to perform embolisation, including ethanol, particles or different kind of glues [3133 ]. inter alia, cyanoacrilic glues seem to represent optimal materials for fistula percutaneous treatment, due to their high adhesive and haemostatic properties and fast polymerisation. a case of embolisation of a fistula with cyanoacrilic glue a, b contrast injection through a previously placed percutaneous drainage (white arrowhead) at the level of a fluid collection (asterisk) demonstrating a fistula (black arrow) with a communication (small black arrowhead) with the biliary system and bowel (b) ; large black arrowhead percutaneous transhepatic biliary drainage. c a guidewire (small white arrowhead) is advanced through the percutaneous drainage (large white arrowhead) into the fistula (black arrow) ; asterisk fluid collection, black arrowhead percutaneous transhepatic biliary drainage, b bowel. d a microcatheter (white arrowhead) is advanced over the wire at the level of the fistula (black arrow), and glue is injected (white arrow) ; asterisk fluid collection, black arrowhead percutaneous transhepatic biliary drainage, b bowel successful percutaneous embolisation with cyanoacrilic glue of a postoperative fistula. a, b contrast injection through a previously placed percutaneous drainage (white arrowhead) at the level of a fluid collection (asterisk) demonstrating a fistula (black arrow) with a communication (small black arrowhead) with the biliary system and bowel (b) ; large black arrowhead percutaneous transhepatic biliary drainage. c a guidewire (small white arrowhead) is advanced through the percutaneous drainage (large white arrowhead) into the fistula (black arrow) ; asterisk fluid collection, black arrowhead percutaneous transhepatic biliary drainage, b bowel. d a microcatheter (white arrowhead) is advanced over the wire at the level of the fistula (black arrow), and glue is injected (white arrow) ; asterisk fluid collection, black arrowhead percutaneous transhepatic biliary drainage, b bowel ir plays an increasing, crucial role in the multidisciplinary management of complications after pancreatic surgery, providing a minimally invasive therapy also in critical patients, reducing recovery times and avoiding re - operation morbidity. ir procedures such as percutaneous drainage of fluid collections, percutaneous transhepatic biliary procedures, arterial embolisation, venous interventions and fistula embolisation are viable treatment options and have been reported as feasible, safe and effective techniques with fewer complications compared with re - look surgery, with a shorter hospital stay and faster recovery in the management of complications after pancreatic surgery. | pancreatic resections are surgical procedures associated with high incidence of complications, with relevant morbidity and mortality even at high volume centres. a multidisciplinary approach is essential in the management of these events and interventional radiology plays a crucial role in the treatment of patients developing post - surgical complications. this paper offers an overview on the interventional radiological procedures that can be performed to treat different type of complications after pancreatic resection. procedures such as percutaneous drainage of fluid collections, percutaneous transhepatic biliary procedures, arterial embolisation, venous interventions and fistula embolisation are viable treatment options, with fewer complications compared with re - look surgery, shorter hospital stay and faster recovery. a selection of cases of complications following pancreatic surgery managed with interventional radiological procedure are presented and discussed.teaching points interventional radiology is crucial to treat complications after pancreatic surgery percutaneous drainage of collections can be performed under ultrasound or computed tomography guidance percutaneous biliary procedures can be used to treat biliary complications venous procedures can be performed effectively through transhepatic or transjugular access fistulas can be treated effectively by percutaneous embolisation |
small - gauge pars plana vitrectomy (ppv) systems have gained wide acceptance in vitreoretinal surgery due to their potential for reduced inflammation and rapid visual recovery.1 recently, valved cannulas have been added to the vitreoretinal surgery armamentarium. they alleviate the need for cannula plugs during instrument exchange and minimize egress of fluid through cannulas during surgery. these advantages allow stable intraocular fluidics and improved dynamic control of intraocular pressure (iop). proliferative vitreoretinopathy (pvr) is the most common etiology for recurrent retinal detachment (rd).2 the pathophysiology leading to pvr formation is not fully understood but thought to be at least partially inflammation mediated in a process analogous to excessive wound healing, driven by migrating and proliferating retinal pigment epithelium (rpe), glial cells, and bone marrow - derived inflammatory cells.3,4 clinically, pvr is currently classified into grades a c, with grade c being the most severe form manifested by preretinal and/or subretinal membranes.5 rd complicated by grade c pvr poses a significant surgical challenge. the optimal surgical approach for grade c pvr, such as use of an adjuvant scleral buckle (sb), inferior retinectomy, choice of tamponade, and vitrectomy gauge, remains controversial.2,6 limited studies demonstrate encouraging surgical success rates when small - gauge vitrectomy systems are employed in the repair of rd with grade c pvr.710 to our knowledge, no studies in the literature have specifically evaluated the use of valved cannulas for rd repair complicated by pvr. it is possible that there is decreased washout of debris and inflammatory products in eyes operated with valved cannulas that may lead to an increased rate of pvr and surgical failures. alternatively, the diminished intraocular fluid currents associated with valved cannula use may cause decreased liberation of rpe cells, resulting in lower rates of induced pvr and improved surgical outcomes. in this study, we retrospectively reviewed outcomes and complication rates of valved vs nonvalved cannula ppv for rd repair complicated by grade c pvr at a single academic institution and found comparable functional and anatomic results as well as complication rates. the study protocol was approved by the institutional review board of the duke university school of medicine. we performed a retrospective chart review of eyes that underwent small - gauge (23 or 25 gauge) ppv with valved vs nonvalved cannulas for rd repair complicated by grade c pvr. the clinical database tool duke enterprise data unified content explorer was used to search for current procedural terminology codes 67108 and 67113, which are associated with vitrectomy for repair of rd.11 the duke vitreoretinal service transitioned to valved cannulas in may 2012 and started exclusive use of valved cannulas in july 2012. the valved group consisted of valved cannula ppv between july 1, 2012 and january 31, 2013 ; the nonvalved group consisted of nonvalved cannula ppv between july 1, 2011 and january 31, 2012. charts were reviewed to identify eyes with rds complicated by documented grade c pvr that were repaired with small - gauge ppv and use of temporary perfluorocarbon liquid (perfluoro - n - octane [pfo ]). the exclusion criteria included use of 20-gauge vitrectomy, no ppv (eg, sb only), diagnosis other than rd (vitreous hemorrhage, epiretinal membrane [erm ], etc), traumatic rd or open globe, no use of pfo during ppv, abortion of the surgery from anesthesia - related complications, and postoperative follow - up <3 weeks. multiple surgeons performed standard three - port ppv using valved or nonvalved cannulas with an alcon constellation vitrectomy system (alcon laboratories, inc., forth pfo was used temporarily to flatten and stabilize the retina during pvr membrane peeling and/or to drain subretinal fluid. based on individual discretion of the surgeon, adjuvant sb was placed, relaxing retinectomy was performed, and silicone oil, octafluoropropane gas (c3f8), or sulfur hexafluoride gas (sf6) tamponade was utilized. for silicone oil fill, automated viscous fluid control injection was utilized in both valved and nonvalved cannula cases. for valved cannulas, either a chimney or a second instrument to displace one of the valve leaflets was used to vent the system, whereas for nonvalved cases, the cannula was left open to vent the system. pfo injection was performed slowly with a single bore cannula, and injection was temporarily halted in the case of optic nerve compromise until reperfusion was noted in both valved and nonvalved cannulas ; the infusion line allowed retrograde fluid flow to alleviate the increased pressure induced by pfo injection. charts were analyzed for baseline demographics and preoperative characteristics (lens status, macula on vs off rd, recurrent rd [ie, unsuccessful prior rd repair ] in the presenting eye, previous placement of sb) and type of surgery (gauge, adjuvant sb, relaxing retinectomy, and tamponade). the primary outcomes included best - corrected visual acuity (bcva) change as well as rate of anatomic reattachment including single surgery success (retina attached at the final follow - up after single operation) and final anatomic success (retina attached at the final follow - up). secondary outcomes included complication rates, including pfo - related complications, postoperative day 1 hypotony, hypertony, and rate of anterior chamber fibrin formation as well as rate of subsequent erm peel after rd repair. visual acuity was converted to logarithm of the minimum angle of resolution (logmar). to facilitate clinical interpretation of results, visual improvement was converted to approximate early treatment diabetes retinopathy study (etdrs) letter improvement scores.12 statistical differences were assessed by either the fisher s exact test or wilcoxon rank sum test. visual acuity was converted to logarithm of the minimum angle of resolution (logmar). to facilitate clinical interpretation of results, visual improvement was converted to approximate early treatment diabetes retinopathy study (etdrs) letter improvement scores.12 statistical differences were assessed by either the fisher s exact test or wilcoxon rank sum test. we reviewed 364 charts (196 in the valved group and 168 in the nonvalved group), of which 201 eyes were excluded based on prespecified criteria (valved cannula group : no pfo [n=38 ], insufficient follow - up [n=26 ], diagnosis other than rd [n=20 ], 20-gauge ppv [n=5 ], and traumatic rd [n=3 ] ; nonvalved cannula group : 20-gauge ppv [n=34 ], no pfo [n=29 ], insufficient follow - up [n=23 ], diagnosis other than rd [n=18 ], no ppv [n=4 ], and surgery aborted because of anesthesia complications [n=1 ]). of the remaining 163 eyes, 67 eyes were documented to have preoperative grade c pvr. there were 36 eyes in the valved group and 31 eyes in the nonvalved group. no significant demographic or preoperative characteristic differences existed between the groups. in the majority of eyes, the rd was macula off (83% in valved eyes vs 81% in nonvalved eyes, p=1.000) and recurrent (67% in valved eyes vs 71% in nonvalved eyes, p=0.795). the mean preoperative bcva was 1.83 logmar (snellen equivalent = 20/1,352) in the valved group vs 2.06 logmar (snellen equivalent = 20/2,296) in the nonvalved group (p=0.127). the majority of eyes underwent 23-gauge ppv (86% in the valved group vs 94% in the non - valved group, p=0.437), and the remaining minority eyes underwent 25-gauge ppv. adjuvant sb was placed in 61% of the valved eyes vs 58% of the nonvalved eyes (p=0.809). relaxing retinectomy was performed in 50% vs 39% in the valved and nonvalved groups, respectively (p=0.461). all eyes received temporary pfo to drain subretinal fluid and/or flatten and stabilize the retina during pvr membrane peeling as per the study inclusion criteria. in both groups, the most common tamponade was silicone oil (72% in valved eyes vs 68% in nonvalved eyes, p=1.000) followed by c3f8 (28% in valved eyes vs 32% in nonvalved eyes, p=0.791). sf6 was not used for tamponade in any of these grade c pvr rd repairs. the final mean bcva in the valved group was 1.47 logmar (snellen equivalent 20/590) vs 1.74 logmar (snellen equivalent 20/1,099) in the nonvalved group (p=0.124). compared to baseline preoperative bcva, the mean logmar improvement at the final follow - up visit was 0.36 in the valved group and 0.33 in the nonvalved group (p=0.824). the corresponding approximate etdrs letter improvement score was + 17 in the valved group vs + 16 in the nonvalved group. no statistically significant differences between the valved and nonvalved groups were found in anatomic outcomes (table 3). the single surgery success was 83% vs 77% (p=0.555) and the final anatomic success was 94% vs 87% (p=0.404) in the valved vs nonvalved groups, respectively. the decision to observe and not to operate on detached retinas was due to poor visual prognosis (n=1 in the valved group, n=3 in the nonvalved group) and patient preference (n=1 in the valved group, n=1 in the nonvalved group). pvr was the most common etiology for recurrent rd in both groups (83% in the valved eyes vs 71% in the nonvalved eyes, p=1.000). alternative etiologies were recurrent rd without documented hole, break, or pvr under silicone oil (n=1, valved group ; n=1, nonvalved group) and recurrent rd without documented hole, break, or pvr 1 month following silicone oil removal (n=1, nonvalved group). intraocular retained pfo was reported in 6% vs 10% of the valved and nonvalved groups (p=0.656), which was removed surgically in 100% (n=3) of the valved group and 0% of the nonvalved group (p=0.100). subretinal retained pfo was detected in 11% of the valved group and 3% of the nonvalved group (p=0.363) and was observed without surgical removal in all cases. there were no significant differences in postoperative day 1 anterior chamber fibrin reaction, postoperative day 1 hypotony or hypertony, as well as subsequent erm peeling between the groups. no cases of iatrogenic retinal breaks due to retinal incarceration at the cannula site were reported in either group. we reviewed 364 charts (196 in the valved group and 168 in the nonvalved group), of which 201 eyes were excluded based on prespecified criteria (valved cannula group : no pfo [n=38 ], insufficient follow - up [n=26 ], diagnosis other than rd [n=20 ], 20-gauge ppv [n=5 ], and traumatic rd [n=3 ] ; nonvalved cannula group : 20-gauge ppv [n=34 ], no pfo [n=29 ], insufficient follow - up [n=23 ], diagnosis other than rd [n=18 ], no ppv [n=4 ], and surgery aborted because of anesthesia complications [n=1 ]). of the remaining 163 eyes, 67 eyes were documented to have preoperative grade c pvr. there were 36 eyes in the valved group and 31 eyes in the nonvalved group. no significant demographic or preoperative characteristic differences existed between the groups. in the majority of eyes, the rd was macula off (83% in valved eyes vs 81% in nonvalved eyes, p=1.000) and recurrent (67% in valved eyes vs 71% in nonvalved eyes, p=0.795). the mean preoperative bcva was 1.83 logmar (snellen equivalent = 20/1,352) in the valved group vs 2.06 logmar (snellen equivalent = 20/2,296) in the nonvalved group (p=0.127). the majority of eyes underwent 23-gauge ppv (86% in the valved group vs 94% in the non - valved group, p=0.437), and the remaining minority eyes underwent 25-gauge ppv. adjuvant sb was placed in 61% of the valved eyes vs 58% of the nonvalved eyes (p=0.809). relaxing retinectomy was performed in 50% vs 39% in the valved and nonvalved groups, respectively (p=0.461). all eyes received temporary pfo to drain subretinal fluid and/or flatten and stabilize the retina during pvr membrane peeling as per the study inclusion criteria. in both groups, the most common tamponade was silicone oil (72% in valved eyes vs 68% in nonvalved eyes, p=1.000) followed by c3f8 (28% in valved eyes vs 32% in nonvalved eyes, p=0.791). sf6 was not used for tamponade in any of these grade c pvr rd repairs. the final mean bcva in the valved group was 1.47 logmar (snellen equivalent 20/590) vs 1.74 logmar (snellen equivalent 20/1,099) in the nonvalved group (p=0.124). compared to baseline preoperative bcva, the mean logmar improvement at the final follow - up visit was 0.36 in the valved group and 0.33 in the nonvalved group (p=0.824). the corresponding approximate etdrs letter improvement score was + 17 in the valved group vs + 16 in the nonvalved group. no statistically significant differences between the valved and nonvalved groups were found in anatomic outcomes (table 3). the single surgery success was 83% vs 77% (p=0.555) and the final anatomic success was 94% vs 87% (p=0.404) in the valved vs nonvalved groups, respectively. the decision to observe and not to operate on detached retinas was due to poor visual prognosis (n=1 in the valved group, n=3 in the nonvalved group) and patient preference (n=1 in the valved group, n=1 in the nonvalved group). pvr was the most common etiology for recurrent rd in both groups (83% in the valved eyes vs 71% in the nonvalved eyes, p=1.000). alternative etiologies were recurrent rd without documented hole, break, or pvr under silicone oil (n=1, valved group ; n=1, nonvalved group) and recurrent rd without documented hole, break, or pvr 1 month following silicone oil removal (n=1, nonvalved group). intraocular retained pfo was reported in 6% vs 10% of the valved and nonvalved groups (p=0.656), which was removed surgically in 100% (n=3) of the valved group and 0% of the nonvalved group (p=0.100). subretinal retained pfo was detected in 11% of the valved group and 3% of the nonvalved group (p=0.363) and was observed without surgical removal in all cases. there were no significant differences in postoperative day 1 anterior chamber fibrin reaction, postoperative day 1 hypotony or hypertony, as well as subsequent erm peeling between the groups. no cases of iatrogenic retinal breaks due to retinal incarceration at the cannula site were reported in either group. while small - gauge systems have been increasingly adopted in the management of a variety of vitreoretinal conditions, only limited knowledge exists regarding their impact on outcomes and complications of complex pathologic conditions such as grade c pvr - associated rd. to our knowledge, the present study is the only series specifically investigating valved cannulas for the repair of rd complicated by grade c pvr. we show statistically equivalent visual improvement, single surgery success, final anatomic success, as well as complication rates with valved vs nonvalved ppv. the study population consists of eyes with complex rd associated with grade c pvr presenting to a tertiary referral center. there is a correspondingly high proportion of recurrent rds and macula off detachments associated with poor preoperative vision and poor anatomic and functional prognosis. in this series, repair with valved cannulas was performed 1 calendar year following nonvalved cannulas, but both groups had comparable baseline demographics and preoperative characteristics. anatomic outcomes of this study, with single surgery success of 83% vs 77% and final anatomic success of 94% vs 83% in valved vs nonvalved eyes, respectively, compare favorably to the literature of traditional 20-gauge ppv as well as the available data on small - gauge ppv for grade c pvr - associated rd repair.7,10,1316 despite anatomic success and overall visual improvement in both groups, functional data demonstrate less encouraging results. sixty - six percent of the valved eyes and 84% of the nonvalved eyes remained with 20/200 or worse bcva at the final follow - up, which is consistent with the previously reported studies on eyes with pvr - associated rd.13,15 in a previous study, we did not identify differences in outcomes or complications with valved versus nonvalved cannulas for a heterogeneous rd population of simple and complex detachments.17 however, we hypothesized that altered intraocular fluidics associated with valved cannulas may modulate the outcome of pvr - associated complex rd repair. decreased intraocular fluid currents with valved cannulas may result in reduced rpe seeding and less recurrent pvr. alternatively, the reduced egress of fluid through valved cannulas may hinder washout of inflammatory proteins, debris, and cells, resulting in higher rates of recurrent pvr. however, for both functional and anatomic outcomes, the study found no measurable difference between valved and nonvalved cannulas. there were trends toward improved outcomes with valved cannulas in this study, and it is possible that this study was not adequately powered to detect this difference. iatrogenic retinal breaks may be a complication of vitrectomy, and reported incidences range from 1.6% to 6.2%.1820 one etiology for iatrogenic retinal breaks is vitreous incarceration, which can occur due to vitreous attraction to open cannulas.2123 the stable fluidics of valved cannulas offers a potential for decreased attraction of vitreous incarceration into the cannulas, which has been shown experimentally in the eyes of rabbit.24 in our series, no case of vitreous incarceration at the cannula site was reported in either group, but it is possible that a larger series will elucidate a difference. the improved stability of intraocular fluidics with valved cannulas requires adjustments to certain surgical approaches. owing to the closed system fluidics of valved cannulas, venting must be performed when injecting additional volume such as silicone oil or pfo. a chimney or a second instrument to displace one of the valve leaflets was used to vent the eye when inserting silicone oil with valved cannulas, whereas with nonvalved cannulas, a cannula was simply left open. typically, slow injection of pfo is sufficient to avoid significant iop rise with both valved and nonvalved cannulas, as the infusion line can allow retrograde flow of fluid (but not air), but if optic nerve perfusion was compromised, temporary pausing of the injection was performed. dual - bore injection cannulas may also be used to avoid iop rise secondary to pfo injection,25 but were not used during the time of this study. while the methods of administration of these agents were similar between valved and nonvalved cannula groups, differences in fluidics may result in important differences in outcomes or complications that were undetected by this study. this is a retrospective study whose data are limited by what was recorded in the medical record. there was a significantly longer follow - up time in the nonvalved group, whose study period was 1 year prior to the valved group, which may bias the nonvalved group toward worse anatomic outcomes. the study times of the two groups were temporally distinct, and although the baseline characteristics and surgical approaches of the two groups were not different, there may have been differences in variables that were not analyzed. on the other hand, these distinct study periods may also reduce selection bias from surgeon preference or based on preoperative characteristics, as choice of valved vs nonvalved cannula use was not at the surgeon s discretion but rather a result of an institutional shift from the use of nonvalved to valved cannulas. this is the first series that specifically evaluated valved vs nonvalved ppv for grade c pvr - associated rd. no differences in functional or anatomic outcomes as well as complication rates were identified between the ppv of valved and nonvalved cannulas. in our opinion, advantages of valved cannulas, including minimal egress of fluid during instrument exchange and associated stable intraocular fluidics, translate into easier and more controlled surgery with equivalent anatomic outcomes in complex grade c pvr rd without measurable increase in complication rates. future studies should focus on improving functional visual results in grade c pvr - associated rd. | purposevalved cannulas are a recent addition to small - gauge pars plana vitrectomy (ppv) and provide stable intraocular fluidics. the goal of this study was to compare outcomes and postoperative complication rates of valved vs nonvalved cannula small - gauge ppv for repair of retinal detachments (rds) complicated by grade c proliferative vitreoretinopathy (pvr).methodsa retrospective chart review of 364 consecutive eyes with either valved or nonvalved cannula ppv for rd repair was performed. the primary outcomes were single surgery and final anatomic success and change in best - corrected visual acuity for repair of rds complicated by grade c pvr.resultswe identified 36 eyes in the valved group and 31 eyes in the nonvalved group with grade c pvr rd. the single surgery success was 83% vs 77% (p=0.555) and the final anatomic success was 94% vs 87% (p=0.404) in the valved vs nonvalved eyes, respectively. the mean final visual acuity gain was 0.36 logarithm of the minimum angle of resolution (logmar ; approximate early treatment diabetes retinopathy study [etdrs ] score = 17 letters) in valved eyes vs 0.33 logmar (approximate etdrs score = 16 letters) in nonvalved eyes (p=0.81). postoperative complication rates including postoperative day 1 hypotony, hypertony, and anterior chamber fibrin formation ; postoperative retention of intraocular or subretinal perfluorocarbon liquid ; and subsequent epiretinal membrane peel were not statistically different between groups.conclusionvalved cannula ppv yields equivalent visual acuity and anatomic outcomes without increased postoperative complication rates compared to traditional nonvalved cannula ppv for grade c pvr - associated rd repair. |
although few would deny that consciousness and attention are intimately intertwined, their precise relationship remains unclear. generally speaking, the first view holds that attention is neither necessary nor sufficient for consciousness (lamme, 2003 ; koivisto., 2005). according to this perspective, even though attention and consciousness regularly occur in tandem, under specific circumstances they can be separated, suggesting that, in fact, consciousness and attention are dissociable processes (koch and tsuchiya, 2007). it follows from this view that it is possible to attend to something one is not conscious of, just as it is possible to be conscious of something while not attending to it. the second view, in contrast, holds that attention is necessary and sufficient for consciousness (posner, 1994 ; prinz, 2000, 2011). according to this perspective, the mechanisms of consciousness and attention are not entirely dissociable although it remains an open question whether the precise relationship between such mechanisms is that of identity, causality, or constituency (block, in preparation). a consequence of this view is that one can not be conscious of something unless one attends to it, just as one can not attend to something and fail to be conscious of it. finally, there is an intermediate position according to which attention is necessary but not sufficient for consciousness (moran and desimone, 1985 ; merikle and joordens, 1997 ; rensink., 1997 ; dehaene. it follows from this view that one can not be conscious of something unless one attends to it, but attending to something is not enough to make one conscious of it, insofar as other processes are required. as such, this third view agrees with the first one in that it denies that attention is sufficient for consciousness, while at the same time agrees with the second view in suggesting that attention is necessary for consciousness. since most research on attention has been limited to perception which in turn is usually confined to vision and, to a lesser degree, audition it is unsurprising to find that most of the discussion on attention and consciousness has focused on conscious perception. however, perceptual contents are not the only kind of mental contents of which we are ordinarily conscious. an important set of conscious mental states which has not been sufficiently addressed within this discussion, is that of memories. when we remember, we usually experience something akin to the reinstatement of the content of a previous experience, which may or may not have been perceptual. to be sure, memory enables us to recall past visual or auditory experiences, but it also brings to mind old nightmares and long - gone aspirations. unlike perception, which allows us to be consciously aware of our present, memory allows us to be consciously aware of our past. as a result, it is natural to wonder whether or not attention plays a role during conscious recollection, and also whether or not that role is analogous to the role it plays during conscious perception. does conscious recollection depend in any way on attention or are they independent processes ? more generally, what is the relationship between attention and consciousness during conscious recollection ? in this paper i want to defend the claim that attention is necessary, but probably not sufficient, for conscious recollection. however, unlike the case of conscious perception, i argue that the kind of attention required during recollection is internal, as opposed to external, attention. this makes the role of attention during conscious recollection significantly similar, but also importantly different, from the role it plays during conscious perception. more precisely, then, i argue that internal attention is necessary, but probably not sufficient, for conscious recollection. to that end, in section i start by justifying the need for clear distinctions among different kinds of attention, emphasizing the difference between internal and external attention. in section internal attention and episodic memory retrieval, i review evidence from behavioral, neuropsychological, and neuroimaging studies suggesting that internal attention is required for the successful retrieval of memorial contents. i argue that internal attention during recollection is what makes us conscious of the contents of retrieved memories. in turn, in section i briefly argue for the probable non - sufficiency of internal attention for conscious recollection. when james remarked that everyone knows what attention is (james, 1890), he was rather overconfident. in reality, there seems to be a substantial amount of disagreement as to what the nature of attention is (styles, 1997). part of the problem is that neither the folk nor the scientific use of the term attention is sufficiently precise. we usually employ the term attention in non - scientific contexts to refer to a wide array of phenomena. the word attention sometimes refers to the way in which we engage in certain cognitive tasks ; like when we play chess attentively rather than distractedly. other times attention means bringing something to the foreground of the mind, as when we mentally single out the player with the ball when watching a soccer game. yet, on other occasions, we use the term attention to explain why we were not aware of certain information as when we justify our failing to remember someone s remark, or our inability to recognize a particular street when ambling absentmindedly, by simply saying that we were not paying attention. the problem is not with our use of the term attention in such circumstances. is not the only term we can employ to convey the same message. in certain contexts we use terms like perceiving, noticing, being aware of, and even being conscious of when we could have easily used the term attending instead. given people often use these terms interchangeably (de brigard, 2010), this lack of semantic precision between the words consciousness and attention becomes more problematic when trying to identify the relationship between the two folk psychological notions, consciousness, and attention. semantic consensus is not found in scientific circles either. on the one hand, there is disagreement as to whether attention refers to a personal or a sub - personal phenomenon (watzl, 2011). specifically, there is disagreement as to whether attention refers to a process one should expect to find a neural correlate for ; or whether it refers to something the person does in virtue of having a brain, but for which it would be a category - mistake to try to find a neural correlate (mole, 2010 ; wu, 2011). on the other hand, there is disagreement as to whether or not attention names a natural kind. for instance, some suggest that attention does not name a single cognitive mechanism, but rather denotes particular ways in which certain cognitive processes can be carried out. listening attentively and observing attentively are not two different processes (i.e., audition and vision) that share a common third mechanism (i.e., attention) ; they are simply two different cognitive processes, carried out in distinctly precise ways that may or may not share common properties (parasuraman, 2000 ; duncan, 2006). as such, it would be a mistake to try to find the neural correlate of attention per se, independently of other cognitive processes. in contrast, one could see attention as a unified cognitive process with either an identifiable sub - personal neural correlate (prinz, 2011), or a set of personal - level phenomena such as behaviors (wu, 2011) or subjective mental contents (smithies, 2011 ; watzl, 2011). those who consider attention reducible to a neural process face the daunting task of identifying a single brain mechanism responsible for all forms of attentive behavior. likewise, those who think that attention could be identified with a series of personal - level phenomena face the difficult task of discerning necessary and sufficient conditions for behaviors or subjective states to qualify as instances of attention. employing different methods, many cognitive neuroscientists working on attention critics of this approach claim that extant empirical evidence strongly suggests that there may not be a single neural mechanism responsible for all forms of attention (wu, 2011). the lack of a common neural denominator for all forms of attention would make it tempting to advocate either for anti - reductionism so that we are to find the essence of attention at the personal rather than the sub - personal neuronal level (mole, 2010 ; watzl, 2011) or for eliminativism, ridding scientific psychology of the term attention (allport, 1993 ; anderson, 2011). after all, not all scientifically useful psychological terms refer to natural kinds, single neural mechanisms. consider memory. memory researchers have struggled for decades to come up with a single unified definition of memory ; something general enough to encompass different kinds of memory (i.e., semantic, episodic, implicit, etc.), but specific enough to separate it from other forms of cognitive and non - cognitive phenomena (tulving, 2002). additionally, extant scientific evidence conclusively shows that different forms of memory are subserved by different neural mechanisms (schacter., 2000 ; nonetheless, despite longstanding disagreements as to what its essence may be, and despite its multiple and disjoint neural implementations, memory is still a useful term in scientific psychology as well as neuroscience. i believe attention might be just like memory. in a recent review, chun. (agree that there are multiple attentional systems that appear to be correlated with different neural mechanisms. but the fact that there may not be a single neural property shared by all attentional systems does not deter them from suggesting that all forms of attention share three essential properties at the computational level. first, according to chun. (2011), attention is essentially a filtering process with limited informational capacity. since the amount of information we live in exceeds our capacity to effectively process it, attention evolved to filter out irrelevant information detrimental to the ongoing cognitive or behavioral task (pashler., 2001). second, attention is essentially selective. in filtering out information for subsequent processing, attention attended information is processed more efficiently and more deeply than information that is not selected by attentional mechanisms. (2011), all forms of attention share these three computational characteristics (i.e., filtering, selectiveness, and modulation), which may or may not be implemented by the same neural mechanism. indeed, they suggest that trying to understand different kinds of attention in terms of their neural mechanisms may not be the best way to proceed. instead, they suggest a taxonomy based on the type of information attention operates over ; what they call the targets of attention. according to chun. (2011) proposed taxonomy, attention can be captured, first and foremost, either by targets in one s surrounding environment (external) or within one s own mind (internal). external attention refers to the filtering, selection, and modulation of externally generated sensory information, whereas internal attention refers to the filtering, selection, and modulation of internally generated information in the form of representations containing information not directly linked to objects in one s immediate surrounding environment. it is worth noting that the division between internal and external attention is similar to, but also importantly different from, categorizations that have been proposed in the past. for instance, attention has been separated into exogenous and endogenous attention (egeth and yantis, 1997). endogenous attention refers to the voluntary selection and modulation of information elicited by top - down mechanisms of orientation and control, such as one s goals and intentions. conversely, exogenous attention refers to the involuntary and bottom - up driven allocation of attention onto a target that is noted or otherwise cognitively highlighted for reasons outside of one s control. endogenous and exogenous attention, however, do not map onto the internal / external classification. after all, external objects can be attended both endogenously as when we voluntarily and in a controlled manner direct our attention to a desired external target and exogenously, as when a particular external target captures our attention involuntarily and in a mandatory fashion. another popular division is between covert and overt attention (wright and ward, 2008). overt attention refers to a shift in attentional allocation accompanied by noticeable eye movements ; whereas covert attention refers to a shift in attentional allocation with the eyes fixed on a certain target. however, as with the endogenous / exogenous dichotomy, the covert / overt distinction does not map squarely onto the internal / external categorization either. for one, as it has been shown experimentally, it is possible to divert attention from one target onto another without concomitant saccadic movements (juan., 2004) which, incidentally, evidences the fact that attention can be spread over a region of space and not only toward individual objects. likewise, evidence shows that attention allocated to internally generated information is often times accompanied by eye movements (hunt and kingstone, 2003). finally, it is extremely improbable that eye movements could provide a useful wedge to divide internal and external attention to non - visual stimuli. therefore, mechanism - based dissociations such as endogenous / exogenous and covert / overt do not map onto the target - based distinction between internal and external attention suggested by chun. (2011). by embracing chun.s (2011) informational target- rather than a mechanism - based taxonomy for attention, i am committing to the very real possibility that internal and external attention may not share the same neural operations. this consequence already appears to be validated by recent studies showing dissociations between brain regions engaged during internal - monitoring tasks and brain regions involved in external orienting and detection tasks (e.g., esterman., 2009). moreover, it is also expected that more fine - grained distinctions within these categories, such as feature- versus object - based attention within external attention, will map onto different neural mechanisms. given this variability in the neural implementation of different kinds of attention, it is difficult to assess general claims like attention is necessary for consciousness or if either of these claims is supposed to capture something about the relationship between the mechanisms of attention and consciousness, they must be modified so as to specify the kind of attention to which they are supposed to apply. since we are concerned here with conscious recollection, where the information of which we are aware is internally generated however, in order to understand the role of internal attention in conscious recollection, it is essential to first explore its role during episodic memory retrieval. as mentioned above, external attention involves the filtering, selection, and modulation of sensory information (chun., 2011). in addition, external attention can be allocated to one or to several sensory modalities, it can be focal or distributed spatially, and it can be transient or sustained. each one of these forms of external attention activates distinct brain mechanism, some of which share certain features. for instance, visual attention enhances retinotopical activation in the visual cortex (tootell., 1998), while auditory attention does so tonotopically in the auditory cortex (woldforff., 1993). thus, although the relevant cortical areas of enhanced activation differ across modalities, the specific processing elicited by attention appears to be similar. likewise, external attention is known to recruit a fronto - parietal network of activation (corbetta and shulman, 2002). however, it has been shown that the timing of this recruitment differs depending on whether attention is goal - directed or stimulus - driven. top - down attention recruits frontal regions of the fronto - parietal network first ; stimulus - driven or bottom - up attention recruits parietal regions first (buschman and miller, 2007). thus, while both top - down and bottom - up attention recruit similar brain regions, the order in which these regions are recruited differs. unsurprisingly, the mechanisms responsible for internal and external attention have much in common. internal attention, defined as the filtering, selection, and modulation of internally generated information, operates over representations of items and events that need not be in the subject s immediate environment. paradigmatically, internal attention operates over representations entertained during decision - making and working - memory tasks, but also as i shall argue below during retrieval of episodic information from long - term memory. studies on task selection, in which competing options are filtered, chosen, and maintained, have shown specific capacity limitations expected from internal attentional processes. for instance, when choices are produced in rapid succession, the second response is delayed if presented less than half a second after the first choice an effect known as psychological refractory period (pashler, 1994). this bottleneck effect parallels well - known external attention effects, such as the attentional blink, in which a perceptual stimulus goes unnoticed if presented in close succession. moreover, neuroimaging studies have shown common recruitment of regions engaged during attentional blink and the psychological refractory period (wong, 2002 ; marois and ivanoff, 2005 ; hesselmann., 2011 ; marti., further neuroimaging studies on task selection have shown recruitment of several brain regions also associated with external attention, such as the prefrontal and anterior cingulated cortices (botvinick., 2001). the overlap between internal and external attention mechanisms is even greater during working - memory tasks. for example, the maintenance of representations in working - memory modulates modality congruent sensory cortices (serences., 2009) likewise, working - memory tasks are disrupted by material - congruent distraction tasks, suggesting once again recruitment of common mechanisms. despite their similarities, internal, and external attention differ in important respects. in an illuminating study, 2004) directly compared brain activity associated with attentional orientation during a perceptual and a working - memory task. although, as expected, both tasks recruited a common network of brain regions, some important differences emerged. in particular, the right inferior parietal cortex, extending onto posterior angular gyrus, was preferentially involved in the orientation of external attention. on the other hand, bilateral intraparietal sulcus, as well as right ventral and bilateral dorsolateral prefrontal cortices, using multivoxel pattern classification (mvpa) analysis they trained a classifier that successfully identified subpopulations of neurons within the superior parietal lobule preferentially associated with either internal or external attention - related activity. finally, recent evidence showing differences between neural regions recruited during internal and external attention tasks comes from a study by sestieri., participants engaged in top - down attentional search tasks looking for stimuli that were either retrieved or perceived. a direct comparison showed preferential activation in the angular gyrus, extending rostrally toward supramarginal gyrus and dorsally toward the intraparietal sulcus, precuneus, and posterior cingulate cortex for the memory search task. in contrast, the medial and ventral banks of the posterior intraparietal sulcus, as well as the superior parietal lobule, were preferentially associated with the perceptual search task. taken together, the evidence just surveyed suggests that even though there is substantial overlap between internal and external attention, there are important differences as well (for a recent review, see chun and johnson, 2011). notwithstanding the substantial commonalities in the neural activations between internal and external attention, recent behavioral evidence is starting to suggest that internal rather than external attention may play a fundamental role during memory retrieval. barring a few exceptions (e.g., johnston., 1970 ; trumbo and milone, 1971), until the mid-1980s most memory researchers thought that, while attention was critical during memory encoding, it was not necessary for episodic memory retrieval. neuropsychological evidence favored this claim, insofar as patients with attentional deficits due to parietal lesions showed no impairments during memory tasks (critchley, 1953). similar conclusions were reached by researchers conducting studies in which attention was manipulated during memory retrieval. in a classic paper, baddeley. (1984) conducted a series of experiments using different attention - demanding secondary tasks during both encoding and retrieval. they found that, during encoding, all attention - demanding secondary tasks consistently impaired subsequent memory tests relative to conditions in which attention remained undisrupted. however, during retrieval, the same secondary tasks left memory performance unscathed. as a result, (1984) suggested that memory retrieval was a relatively automatic and mandatory operation that did not require the allocation of attentional resources. since then, numerous studies have confirmed and clarified the essential role attention plays during episodic memory encoding (for a review, see chun and turk - browne, 2007). this dominant view has been recently challenged by a series of innovative studies showing that, under certain conditions, divided attention during episodic retrieval can actually affect memory performance. in a pioneer study, fernandes and moscovitch (2000) showed that when people engage in a material - congruent secondary task in a divided attention paradigm during retrieval, performance significantly decreases relative to a baseline in which the memory test is the only task. in a related study, hicks and marsh (2000) showed that under deep encoding conditions divided attention at retrieval significantly reduces successful recollection. indeed, they argue that previous studies failed to find effects of divided attention during retrieval precisely because they used shallow as opposed to deep encoding strategies. as a result, hicks and marsh (2000) hypothesize that, consistent with the dual - process theory of recognition memory, successful memory retrieval requires attention only when it is recollection- rather than familiarity - based (yonelinas, 2002). the necessity of attention for material - congruent and recollection - based memory retrieval was nicely confirmed by skinner and fernandes (2008) who, employing a remember / know paradigm typically used to tap at differences between recollection and familiarity, showed that divided attention during retrieval only affected know responses for material - congruent items. when the secondary task involved contents that differed from the target material (e.g., numerical tasks during retrieval of verbal information), and such materials were shallow versus deeply encoded, divided attention did not affect memory performance. finally, lozito and mulligan (2006) extended these results by showing that, under conditions of strategic encoding (that need not be semantic) divided attention produces detrimental effects at retrieval. taken together, the results of these and related (e.g., fernandes., 2005 ; skinner., 2009) studies suggest that divided attention affects recollection of strategic, deeply encoded information when attention is directed to material - congruent contents. in addition to using shallow encoding strategies, previous studies failed to find an effect of attention during recollection for another reason : they either employed attention - diverting tasks with external targets (e.g., serial search) rather than internal targets, or they used material - incongruent tasks (e.g., number counting in verbal tasks) that did not demand the use of resources that internal attention was allocating to the process of recollecting memories. however, when the concurrent attention - diverting task employed during memory retrieval targeted internal and material - congruent contents, recollection was significantly impaired consequently, focusing one s internal attention upon the to - be - retrieved material appears to be necessary for successful recollection of episodic memories. indeed, this claim is further supported by recent neuropsychological studies on patients with parietal damage. as mentioned above, the traditional view is that patients with parietal lesions do not exhibit memory deficits. however, recent studies suggest that when recollection requires demanding internal maintenance and monitoring of retrieved information, patients with parietal damage show significant impairments relative to healthy controls. for instance, berryhill. (2007) reported that, when compared with healthy controls, patients with bilateral ventral parietal lesions showed reduced levels of free - recall during autobiographical memory tasks as opposed to cued - recall, where they show no impairment. in addition, when compared with matched controls, patients showed decreased levels of vividness and number of details in their recollections during free- as opposed to cued - recall. curiously, when considered from the point of view of free - recall, a classic study conducted by bisiach and luzzatti (1978) appears to be consistent with the claim that parietal damage impairs voluntary retrieval of stored information. bisiach and luzzatti (1978) asked a patient with a parietal lesion resulting in severe hemispatial neglect, to remember the main square in milan, the city in which he had lived all his life. despite claiming to know the square quite well, the patient s report omitted the buildings to the left of the square when he tried to remember it facing one direction. when asked to imagine crossing the square and turning back, so he would be now facing the other direction from the opposite side, he omitted the buildings to his left even though he had just reported them. this surprising observation strongly suggests that damage to the parietal cortex, critical for the selection, and maintenance of visual information in external attention tasks, is also critical for the voluntary selection and maintenance of internal information during memory retrieval in conditions of free - recall. the involvement of the parietal cortex during episodic memory retrieval has been a systematic finding in neuroimaging studies. for that reason, some theorists suggest that the role the parietal cortex may be playing during recollection is tantamount to the role it plays during visual perception. one of the most explicit articulations of this view has been put forth by cabeza and colleagues (e.g., cabeza, 2008 ; cabeza. (atom) hypothesis, the dorsal parietal cortex, which is usually associated with top - down attention, is involved in voluntary, goal - directed attention, whereas the ventral parietal cortex, which is usually involved in bottom - up attention, appears to be associated with involuntary recollection (see hutchinson., 2009, for some counter - evidence, but also cabeza., 2011, for a response). another hypothesis suggests that the parietal cortex may play a role analogous to the working - memory buffer suggested by baddeley. (1998), insofar as it is required for gating stored information for decision - making and action (wagner., 2005). finally, one recent hypothesis the cortical binding of relational activity (cobra) suggests that the parietal cortex may modulate the reactivation of disaggregated sensory components during retrieval in order to bind them in the unified whole we experience during recollection (shimamura, 2011). although the jury is still out as to which of these views best captures the role of the parietal cortex during memory retrieval, for the present purposes it suffices to say that they all agree in that it plays a critical role in the selection (either voluntary or involuntary), modulation (either top - down or bottom - up), and maintenance of internally generated information which, according to the operational definition used above, means that it plays a critical role during internal attention to memory representations. in sum, the evidence reviewed in this section suggests that internal attention is required for the retrieval of episodic memories. behavioral studies using divided attention paradigms show that when internal attention to material - congruent deeply encoded information is disrupted during retrieval, recollection is significantly impaired. in addition, neuropsychological studies in patients with parietal cortex damage, which usually results in attentional impairments to external stimuli, also suggest that under free - recall conditions they tend to retrieve less perceptual details from their autobiographical memories relative to both cued - recall and healthy controls. finally, extant data coming from neuroimaging studies shows the involvement of attention - related parietal regions during episodic retrieval, further supporting the idea that internal attention plays a critical role during recollection. however, even if attention is required for episodic retrieval, there is still a further question as to whether it is necessary for conscious recollection that is, the subjective experience of reliving the retrieved memory. in the next section i argue that this question should be answered in the affirmative. the evidence reviewed so far suggests that internal attention is required for episodic memory retrieval. i now want to suggest that internal attention is also a necessary mechanism by means of which we become conscious of successfully retrieved memories. first, neuropsychological and neuroimaging studies show that the prefrontal cortex is involved in the initiation, monitoring, and maintenance of the retrieval attempt (buckner and wheeler, 2001). in particular, it has been suggested that the ventrolateral regions of the prefrontal cortex are involved in the initiation and maintenance of episodic memory retrieval, while the dorsolateral regions have been associated with the updating and manipulation of retrieved features (wagner, 2002 ; cabeza and st. temporal lobes previously thought to be involved only during memory encoding (but see squire, 2004) are also required for the successful binding and accessing of relational information from the neocortex during memory retrieval (gilboa. 2006). finally, as mentioned in the previous section, it is now well accepted that the parietal cortex is involved in memory retrieval. although its precise role remains elusive, extant theories suggests that it plays a role in the filtering and selection of information distributed in the sensory cortices (shimamura, 2011). it has also been suggested that this prefrontal / medial temporal / parietal network of activation associated with episodic memory retrieval plays a critical role in the informational processing that gives rise to conscious awareness of mental contents. this suggestion has been thoroughly developed within the influential framework of the global neuronal workspace (gnw) model suggested by dehaene and changeux (2000 ; see also dehaene., 2003, 2006 ; changeux and dehaene, 2008 ; and dehaene and changeux, 2011). briefly stated, the gnw model postulates two computational spaces in the brain, characterized by different patterns of connection. on the one hand, there is a processing network, which is seen as a set of local, informationally encapsulated, functionally specialized, and domain specific processors with limited numbers of medium - range connections. on the other hand, there is the gnw, which is characterized by distributed sets of cortical networks with long - range excitatory and inhibitory connections, allowing them to send and receive projections from distant areas in a global and flexible manner, so that the information these networks processes is neither encapsulated nor domain specific. the projections that compose the gnw originate from pyramidal cells from layers ii and iii, the number of which is particularly high in lateral prefrontal, parietal, and medial temporal cortices, specifically in the hippocampus, entorhinal, perirhinal, and parahippocampal cortices (von economo, 1929 ; see also changeux and dehaene, 2008). thus, according to the gnw hypothesis, informational inputs that enter the global neuronal workspace constitute the mental contents of which we are consciously aware. the claim that attention is necessary for retrieved memories to become conscious becomes clear when it is considered from the point of view of the gnw hypothesis. assuming that what we know about the neural correlates of recollection is roughly accurate, the lateral prefrontal cortex would presumably initiate the process of retrieval (rugg., 2002). information is thus projected onto the ventral parietal cortex as well as the hippocampal and parahippocampal gyri, where stored indices of distributed sensory information would enable the binding of disaggregated memory traces (nadel and moscovitch, 2001). then, dorsal regions of the parietal cortex would support the maintenance of the selected information via amplifying the signal from the local processing networks where it resides. when the signal reaches a certain threshold most likely within the gamma frequency of 30100 hz (jensen., 2007 ; see below) the local sensory information that forms the memory trace would be broadcasted onto the global neuronal workspace which, by the gnw hypothesis, renders the memory not only conscious but also available for action. since attention appears to operate via neural synchronization (e.g., steinmetz., 2000), it follows that attention is the mechanism required to enhance gamma - band responses in local processing networks, which in turn renders them available for broadcasting onto the global neuronal workspace. since these local processing networks represent stored rather than externally generated information from the immediate surrounding environment, the kind of attention required to render it available to the global neuronal workspace is internal instead of external attention. evidence in favor of the claim that internal attention permits the broadcasting of locally processed memory representations onto consciousness, comes from several electrophysiological and neuropsychological studies. as previously mentioned, attention appears to act upon local networks by modulating their synchronized firing (steinmetz., 2000). neuronal synchronization increases neuronal firing, which in turn promotes synaptic plasticity (wespatat., 2004). such neuronal changes have been correlated with increases in the gamma frequency of the relevant local network, which may explain why gamma - frequency activity predicts successful encoding during memory tasks, as confirmed by numerous eeg and meg studies (e.g., sederberg. critically, increases in gamma activity have also been correlated with successful retrieval of old items versus correct rejection of new items (gruber., 2004 ; osipova., 2006 ; for a review see jensen., 2007). moreover, in a recent study involving intracranial electroencephalographic recordings in 52 patients with epilepsy, sederberg. (2007) discovered that the same pattern of gamma - frequency activity that predicts successful encoding reappears at retrieval. of note, this oscillatory activity emerges in the prefrontal cortex and the hippocampus, and then spreads onto the sensory cortex this finding, coupled with previous results showing the involvement of parieto - occipital regions in the modulation of gamma - frequency activity during recollection (osipova., 2006), gives further support to the claim that the prefrontal / medial temporal / parietal cortex plays a critical role in gating information from local sensory networks onto the global neuronal workspace. behavioral studies conducted with individuals who suffered parietal lesions give further support to the claim that internal attention gates memories into consciousness. if, as hypothesized, parietal regions modulate the availability of local sensory representations onto the global neuronal workspace, one should expect a diminished sense of re - experiencing or autonoetic consciousness in patients whose parietal lesions hinder such broadcasting. indeed, this prediction has been recently confirmed. (2007) tested autobiographical recollection in patients with bilateral parietal lesions and showed that, during free - recall, these individuals exhibited fewer episodic details and reported lower levels of vividness in their recollections, suggesting that a reduced number of sensory representations were actually made available to their conscious experience. in a related study, davidson. (2008) reported that patients with parietal lesions showed a reduced number of remember responses, which are associated with increased subjective experience of recollection, relative to both know responses and controls. (2010) also found reduced levels of remember relative to know responses in patients with parietal lesions using the desee / roediger - mcdermott (drm) paradigm 2010) found that patients with bilateral parietal damage showed lower confidence levels for source recollection tasks, a result they interpret as suggesting that parietal lobe lesions impair subjective experience of episodic recollection. the view that internal attention is required for conscious recollection is entirely consistent with their interpretation. finally, the claim that internal attention is necessary for conscious recollection also finds support when one considers cued - recall albeit this foundation is perhaps more speculative. the fact that richer retrieval cues increase the likelihood of successful retrieval is at the heart of the notion of retrieval support, but it also suggests that these richer cues work precisely because they have a better chance of highlighting the relevant memory trace than poorer retrieval cues. this thought lies at the foundation of tulving s (1982) classic synergistic ecphory model, according to which the subjective sense of recollection occurs when the memory trace interfaces with the retrieval cue a process he, following semon (1904), called ecphory. although little is known about the neural underpinnings of ecphory, research on memory reinstatement suggest that cued - recall facilitates the reactivation of regions engaged during encoding (rugg. (2011) used electrocorticographic recordings in 69 patients during study and cued - recalled tests. they found that the recorded electrophysiological pattern of brain activity during encoding correlated with the pattern at retrieval. critically, when successful reinstatement was evidenced it occurred within the gamma - band, suggesting the modulation of attentional mechanisms. this activity may be related to bottom - up attention, as suggested by cabeza s (2008) atom model. it may also relate to the phenomenon of spontaneous autobiographical recollections that occur when unexpected stimulus, acting as powerful cues, manage to unintentionally trigger episodes from our past (berntsen, 2010). further research is needed to understand the precise ways in which bottom - up internal attention may render memories conscious. nonetheless, the evidence reviewed in this section strongly suggests that internal attention is not only necessary to successfully retrieve episodic memories : it is also needed to render them conscious. although internal attention is necessary for retrieved contents to become conscious, recent evidence suggests that is not sufficient. the first reason is that successful episodic recollection requires that the memorial contents one internally attends to are effectively reinstated during retrieval. striking evidence in favor of this claim comes from studies with patients suffering from visual amnesia. rubin and greenberg (1998) reported 11 cases of patients with focal lesions in occipital cortex. they did show marked deficits in remembering visual details from their episodic autobiographical memories, the non - visual details of which they were still able to remember (greenberg., 2005). similar observations can be found in patients with certain kinds of visual agnosias, such as color and spatial location ; these patients recollection of color and spatial details is impaired relative to their recollection of other preserved visual details, such as volume or directionality (farah., 1988). if my rendition of the gnw model as it applies to conscious recollection is roughly correct, then we can find an explanation as to why these patients can not access these particular informational contents consciously : it is not because they can not attend to them, but rather because, when they try to, there is nothing to attend to. the damage in the occipital cortex makes it impossible to reinstate the sensory content which, had it been internally attended, would have been consciously recalled. further support for this claim comes from a recent behavioral experiment conducted by guerin. participants were presented with a recognition test in which they had to select one of three items. critically, in one condition, participants saw two related items, both of the same kind as the studied item, plus a non - related item. none of the items was the studied item itself. in another condition, participants saw one non - related item and two related items, one of which was, in fact, the target item. importantly, in the condition where the two related items that did not include the target item, participants false alarm rate was at baseline level ; whereas, in the condition in which one of the two related items was the target item, participant s false alarm rate was significantly reduced. eye - tracking data collected during this study showed that in both cases participants were selectively attending to the perceptual differences between the related items. however, given the difference in false alarms, it appears as though the use of attention to perceptually discriminate between two related foils was not sufficient for the accurate retrieval of the target item. however, once the content was reinstated as when the target item was actually seen next to a foil it was more likely to capture internal attention, rendering it accessible for conscious recollection. this result suggests that, in addition to directing one s internal attention to stored contents, the presence of such contents is required for attention to render them conscious during recollection. as a consequence. the second reason attention may not be sufficient for conscious recollection has to do with the fact that attention is not an all - or - nothing process. it may be possible that, being a modulatory mechanism, attention can render contents conscious only if a certain threshold is reached. indeed, this is a fall - out of the gnw model (dehaene., 2003). it has also been proven experimentally in numerous studies showing that, under specific conditions, certain stimuli can exhibit attentional - cuing effects even at the neuronal level and yet those same stimuli go completely unnoticed by the subject (see, for instance, van boxtel., 2010, for a review). the same may occur with memory traces that, for one reason or another, can not reach the conscious threshold even when modulated by internal attentional mechanisms. in fact, it may be possible that unattended memory representations are responsible for certain priming effects as well as familiarity - based recognition judgments (paller., 2009). further research is needed to clarify the conditions under which internal attention to memory representations may suffice to render them conscious. while this review only scratches the surface of a rather convoluted puzzle, i believe that the evidence surveyed in this paper strongly suggests that internal, as opposed to external, attention is necessary but maybe not sufficient for conscious recollection. perhaps the most pressing one consists of defining the precise mechanisms involved in the kind of internal attention required for conscious recollection. not only is there substantial disagreement as to the extent of the overlap between the neural correlates of external and internal attention (chun and johnson, 2011), there is also disagreement as to the precise role each kind of attention plays during conscious experience. another critical question concerns the role that attention plays during familiarity - based rather than recollection - based recognition (yonelinas, 2002). moreover, patients with parietal damage report significantly reduced numbers of know versus remember responses and lower confidence ratings, which are thought to track subjective feelings of remembering, suggesting that their recollective experience is impoverished (davidson., 2008). further research will be critical in illuminating the role that internal attention plays in differentiating recollection from familiarity. finally, it is also possible that the dispensability of internal attention during procedural memory performance could help us understand the difference between implicit and explicit memory (schacter, 1992). although much is known about the neural mechanisms responsible for these two kinds of memory, the precise role internal attention plays if at all during retrieval of implicit information is still understudied. in a pioneer study, gooding. (1999) tested participants on an implicit word - stem completion test under divided attention conditions and found no differences in performance relative to full attention. similar results were found using related paradigms, such as artificial - grammar learning tasks (helman and berry, 2003) and repetition priming (clarke and butler, 2008), supporting the hypothesis that attention does not play a critical role during the retrieval of implicit memory. strong support in favor of this view comes from recent studies by lozito and mulligan (2010). using a variety of implicit memory tasks such as perceptual identification and category exemplar production tests under divided attention conditions, lozito and mulligan (2010) found no effect of divided attention during implicit retrieval, and also no performance costs for the secondary task. to the best of my knowledge, the only study showing some reduction in priming during divided attention conditions at retrieval is kinoshita (1999), who used a re - arranged word - stem completion task. as such, it remains a possibility that specific kinds of implicit tasks could require some level of attentional allocation. further research is needed to understand this particular issue, and its relation to the more general question of the role of attention in conscious recollection. the author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. | most research on the relationship between attention and consciousness has been limited to perception. however, perceptions are not the only kinds of mental contents of which we can be conscious. an important set of conscious states that has not received proper treatment within this discussion is that of memories. this paper reviews compelling evidence indicating that attention may be necessary, but probably not sufficient, for conscious recollection. however, it is argued that unlike the case of conscious perception, the kind of attention required during recollection is internal, as opposed to external, attention. as such, the surveyed empirical evidence is interpreted as suggesting that internal attention is necessary, but probably not sufficient, for conscious recollection. the paper begins by justifying the need for clear distinctions among different kinds of attention, and then emphasizes the difference between internal and external attention. next, evidence from behavioral, neuropsychological, and neuroimaging studies suggesting that internal attention is required for the successful retrieval of memorial contents is reviewed. in turn, it is argued that internal attention during recollection is what makes us conscious of the contents of retrieved memories ; further evidence in support of this claim is also provided. finally, it is suggested that internal attention is probably not sufficient for conscious recollection. open questions and possible avenues for future research are also mentioned. |
it is widely accepted among pediatric health care providers that the risks of developing coronary artery disease (cad) start in early life. hypertension (ht) is a major modifiable risk factor in the development of cad. identification of ht at an early age may allow early intervention to prevent future end organ damage. despite ample literature studying ht in animals and humans, our understanding of pediatric ht many questions regarding the long - term effects of antihypertensive therapy on growth and development remain unanswered. until recently, normal blood pressure (bp) values have been scarce especially in the very young due to the relative difficulty of measuring bp in this age group. the wide availability of oscillometric bp devices have made bp measurement more feasible especially in young children. furthermore, several normative bp values are now available. thus, the measurement of bp in infants and children at the office and hospital should now be easier and more reproducible. hypertension is a hemodynamic manifestation of total vascular resistance (tvr), and cardiac output (co) tvr is a function blood vessel wall elasticity, myocardial contractility, and cardiac afterload. cardiac output is the product of cardiac stroke volume (sv) and rate (hr). both myocardial contractility and hr are regulated by sympathetic nerve activity. sv depends on myocardial contractility and preload. during the early stages of hypertension, co is often increased. as hypertension progresses, tvr increases and co normalizes. in a certain group of patients, hypertension develops primarily due to a decrease in the cross - sectional area of peripheral arterioles leading to an increase in resistance to flow. tvr is controlled by the interaction of vasodilators such as prostaglandins and bradykinins and vasoconstrictors such as platelet - derived growth factor (pdgf), thromboxane, and angiotensin ii. this group includes patients with renal disease, african american children, and certain genetic forms of hypertension. a prevalent operational designation of hypertension is bp elevation above the 95% percentile for either age, height, or tanner stage and gender, using standardized measurement techniques on at least three separate occasions. the normative sporadic bp values were updated in 2004 by the fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents from the united states of america (us). this task force has incorporated previous data from us children and added new data from the 1999 to 2000 national health and nutrition examination survey (nhanes). blood pressure values are based on gender, age, and height, and 50th, 90th, 95th, and 99th percentiles are provided. while this data is accepted and used worldwide normative data from other regions of the world is available. some regional normative data significantly vary from us data, stressing the ethnic variability in bp. the joint national committee on prevention, detection, evaluation, and treatment of high bp (jnc7) further stratified hypertension in adults into prehypertension and 2 stages. in 2004, the fourth report recommended childhood classification. stage 1 htn is defined as being from the 95th to the 99th percentile plus 5 mmhg. stage 2 htn is 5 mmhg or more above the 100th percentile and represents a level of bp that requires prompt evaluation. actual bp measurement among 10 19-year - old school children, shows that the prevalence of hypertension is close to the predicted rate at 4.5%. risk factors associated with hypertension include gender (males), ethnicity (african americans and hispanics), and increased bmi can increase the prevalence of hypertension among certain high risk groups. the prevalence of hypertension among obese children is much higher estimated to be as high as 11%. children with hypertension have 2.5 times the risk of becoming adults with hypertension. from these studies one may conclude that prevention of risk factors for the development of hypertension, such as obesity, may delay or prevent adult hypertension. symptoms of hypertension in childhood can vary depending upon the severity and duration of hypertension. mild to moderate hypertension is often asymptomatic, while severe hypertension can present with encephalopathy and acute loss of vision (posterior reversible encephalopathy syndrome, pres). determining the duration of hypertension at presentation is of clinical consequence as it helps narrow down the list of differential diagnosis. establishing the duration of hypertension starts by obtaining a comprehensive history. such interview should focus on symptoms associated with hypertension such as poor sense of well - being, poor sleep, restlessness, poor growth, nose bleed, all with the potential to suggest chronic hypertension. frequent headaches, blurred vision, chest pain, symptoms of congestive heart failure, and encephalopathy seizure all could point to an acute onset of hypertension. as most clinical conditions in pediatrics, etiology of hypertension is age specific, table 1, as we and others have previously shown. as such, neonatal period, prematurity low birth weight, prolonged oxygen therapy, and history of umbilical artery catheters may provide clues as to the etiology of hypertension. also history of urinary tract infection in infancy glomerulonephritis and in adolescent females, history of urinary tact infections or dysfunctional voiding may suggest a cause for hypertension. symptoms of systemic illness also could include pallor, flushing, joint pains, rash, edema, gross hematuria, excessive weight gain or loss, or decreased height growth which may suggest vasculitis or glomerulonephritis. triad of flushing, palpitations and, hypertension are often suggestive of pheochromocytoma, a rare cause of hypertension in this age group. in adolescents history history should question the occurrence of headaches, sleep disturbance, visual symptoms, nosebleeds, palpitations, and episodic rapid pulse. sleep disorder, snoring fatigue could be associated with obstructive sleep apnea, a condition overlooked in older children. excessive intake of sodium or caffeinated beverages, and energy drinks is associated with hypertension. a medication history should include specific questions about over - the - counter drugs like pseudoephedrine or herbal preparations like ephedra, st. adolescents should be questioned in private to obtain a history of substance abuse or the possibility of pregnancy. history of current or recent prescription medications such as decongestants, corticosteroids, and nonsteroidal anti - inflammatory could all suggest a cause for hypertension. office hypertension also known as white coat effect is not an uncommon cause of referral for evaluation to the specialist. studies have shown that repeated bp measurement can lower the incidence of office hypertension. a complete physical exam should focus on signs associated with the disease process that caused hypertension and signs of end organ damage associated with hypertension. an infant with hypertension abdominal mass could suggest congenital kidney disease, and pulmonary findings could suggest bronchopulmonary dysplasia. in older children, four extremities bp check is an essential part of a physical exam of a child with hypertension to evaluate for coarctation of the aorta. caf - au - lait spots could suggest neurofibromatosis often associated with hypertension either due to pheochromotocytoma or renal artery stenosis. signs of cv disease as a complication of hypertension include gallop, tachycardia, rales, decreased breath sounds, and so forth. in severe hypertension, lethargy, loss of vision (pres), and signs of stroke signs of excessive steroids such as cushing syndrome, for example, truncal obesity, buffalo hump, round moon faces, and hirsutism. height and weight to calculate bmi is an essential part of the physical exam when evaluating a child with hypertension. basic laboratory tests including basic chemistries, cbc, urinalysis, and renal sonogram are what the practioner should request in children who have stage 1 hypertension ; please refer to table 3 for details. if the child is symptomatic or show signs of end organ damage or symptoms of secondary causes of hypertension the gp should promptly refer the child to the specialist. end organ damage are often rare in children but can include concentric hypertrophy of left ventricular, proteinuria, microalbuminuria, and retinopathy. the younger was the age at presentation with hypertension, the higher are the chances that we find its secondary cause. table 4 lists some of the biochemical and imaging tests often recommended to evaluate a child with hypertension. pharmacological therapy when employed should aim to control elevated blood pressure with the lowest dose and minimal number of drugs, thus minimizing potential toxicity, expense and simplifying the therapeutic regimen. the level to which elevated blood pressure is to be lowered in children and adults remains an arbitrary clinical decision. in adults, the relationship between diastolic blood pressure and the risk of cardiovascular mortality appears to be j - shaped, that is, the risk of developing cardiovascular mortality declines with lowering diastolic blood pressure up to a nadir beyond which further drop in blood pressure will increase morbidity. it is often desired to drop diastolic blood pressure to levels between 80 and 90th percentiles for age. there are two accepted modalities to treat hypertension in pediatrics, namely, nonpharmacological and drug therapies. the type of therapy used often depends on the age of onset, duration, and the severity of ht. it is generally accepted that borderline hypertension (9095th percentile for age) with no evidence of end - organ damage can be treated with nonpharmacological remedies. stage 2 hypertension the other hand (above 99th percentile) often requires admission to hospital for comprehensive management. the safest therapeutic intervention to manage mild ht is the use of nonpharmacological remedies. evidence for the efficacy of this type of intervention in children is not yet established. nonpharmacological intervention has traditionally been focused on the reduction in dietary sodium intake along with high potassium (if there is no clinical contraindication) and on weight loss when the patient is obese. while there are no strong evidence in children about the effect of avoidance of tobacco, alcohol, and stress on bp control, these are desirable practices should be promoted through pediatric counseling. it should be instituted whenever ht is severe or when nonpharmacological intervention alone fails to control the bp in mild to moderate ht. major questions with regard to the long - term effects of antihypertensive drug treatment on growth and cognitive function in children remain unresolved. in addition, the absence of adequate information regarding drug interaction, volume of distribution, protein binding, metabolic degradation, and renal and hepatic excretion introduces additional concerns when treating ht in children. as such most antihypertensive drugs, however, carry a disclaimer relating to their use in children. a large number of antihypertensive agents with various sites and mechanisms of action are commercially available. each drug has undergone extensive evaluation in adult volunteers in pre- and postmarketing clinical trials. the availability of newer drugs allows us to make a rational choice of antihypertensive therapy. the first step in the treatment of hypertension involves a small dose of a single drug, usually a diuretic, the dose is increased until bp goals are achieved, side effects appear, or a maximum dosage is reached. if the bp is not controlled, in spite of adequate compliance, a second and even a third drug is then added. recently, a different approach to antihypertensive treatment has become increasingly popular where therapy is individualized. while vasodilators can lower high bp of almost any etiology, understanding pathophysiologic mechanisms leading to the bp elevation helps in selecting targeted therapy aimed at better control of ht. table 3 provides guidelines for the selection of antihypertensive drugs based on our knowledge of the pathogenesis of ht in an individual child. using these guidelines, we often initiate therapy with a calcium channel blocker agent, an ace - i or a beta - adrenergic antagonist. these drugs are available in once - a - day dosage and have few side effects, both features reflecting positively on adherence. if monotherapy with angiotensin converting enzyme inhibitors, beta - blockers or calcium channel blockers fail to correct bp within two weeks, a diuretic or a mild vasodilator like hydralazine or prazosin are often second line therapy. a final step is to use a potent vasodilator like minoxidil or a centrally acting agent like clonidine. often, combination therapy from different antihypertensive classes is required to achieve control of bp. treatment of severe ht, on the other hand, requires admission to the hospital for frequent bp monitoring. for more detailed review of medications used for treatment of hypertension, while treatment 's potential to alter long - term outcome of hypertension in children sounds intuitive, clear evidence is lacking. what is certain is that children with hypertension require frequent monitoring for end - organ damage from hypertension as well as the potential complication of antihypertensive therapy. it is then rather instinctive that prevention of risk factors associated with hypertension in childhood, such as obesity, may delay or prevent adult hypertension. furthermore, the development of cardiovascular disease and renal disease later in life is also suspected to be associated with childhood hypertension. hence, it can not be overemphasized that early detection of hypertension by routine measurement of bp is an essential part of any office visit. | over the past several decades, childhood hypertension has undergone a considerable conceptual change, as hypertension is a predictor of future development of cardiovascular disease in adults. childhood hypertension has distinctive features that distinguish it from hypertension in adults. pediatric hypertension is often secondary. it is widely believed that therapeutic intervention at an early age favorably modifies the long - term outcome of hypertension. despite its significance as a cause for morbidity, childhood hypertension is underdiagnosed and less studied with many basic issues remaining contentious. |
it is a discipline which explores whether human behaviors are good or bad, right or wrong, and sees itself as the science of moral act. in organizations, including educational institutions, ethics can be defined as a set of formal and informal standards for directing people how to guide their behavior. generally, these standards are derived from core values, such as honesty, respect, and trust and formalized in the mission and value statements. in general, the teaching learning interaction is complex and its effectiveness depends on the teaching and learning styles of the instructors and the students. moreover, the nurse educator is in a unique position to assess cognitive, emotional, and learning strengths and weaknesses in order to contact with the students. although nursing faculties may believe that they possess a core of knowledge about ethical interactions with the students, they may unwittingly risk crossing an ethical boundary in the learning environment. the ethical dimension in education exists because the instructor has the authority to contribute to or impede the students acquisition of knowledge. clinical teaching excellence could be achieved by having effective clinical instructor characteristics such as professional competence, expert knowledge, demonstrable clinical competence with skills in clinical teaching, positive interpersonal relationships with students that portray confidence, respect, support and accessibility, with effective communicative and collaborative skills. schmitz and schaffer (1995) reported that nursing students believed the greatest violation of ethics by nursing instructors was lack of caring about the students. caring was identified as an important element for managing positive relationships by both the student nurses and faculties and was an important aspect of the student nurses learning experiences. in one study surveying the professors ethical attitudes toward the students, ethical professors were those who were fair, did not ignore cheating among the students, and did not take advantage of their position or authority. to understand the registered nurse students perceptions of the importance of faculty behaviors, viverais - dresler and kutschke (2001) examined the responses of 56 participants. the data from answering open- and close - ended questions supported a profile of a teacher of clinical nursing who was accessible, impartial, direct, honest, and fostered mutual respect. kibler found that disciplinary policies and faculty assistance were the factors which affected a student 's level of ethics. (1996) contend that all educators should be proactive in the development of principles for their ethical behavior. the society for teaching and learning in higher education identified several concepts basic to the core of ethical teaching in higher education, including content competence, current high - level skills specific to a clinical area, confidentiality, and ensuring that students have the right to trust the instructor to treat specific issues, such as grades, class attendance, and private communication, in confidence and with privacy. a better understanding of how students view the ethical behavior of their instructors may help not only the understanding of their behaviors but also the awareness of the importance of acting as role models to their students. although ethical behaviors in clinical nursing practice and areas of nursing research have been already studied, there are a limited number of researches focusing on ethical concerns among baccalaureate students of nursing and midwifery with their educators. nursing and midwifery students need to learn more about ethics in order to prevent violations of ethical issues from occurring, once they enter the workplace. by having students learn and understand ethics in college, they will be more prepared to successfully incorporate these principles into their profession. nursing students also have the right to be taught with good quality, treated appropriately, and know what ethical behavior is. therefore, they need role models to enhance their approach toward patients and their families as well as other professional team members. presence of unethical behavior in nursing and midwifery instructors, violates the teaching and learning environment for students and may lead to a non caring atmosphere for patients. as mentioned, since a paucity of the data about ethical concerns between undergraduate nursing students and nurse educators in educational context especially in our nursing and midwifery schools exists, we decided to do this descriptive study to determine the views of iranian baccalaureate nursing and midwifery students regarding the occurrence rate of their faculties unethical behaviors. nursing and midwifery students, enrolled in the fall of 2008, served as the study population. the total population (baccalaureate nursing and midwifery students) under the study were 400 students (nursing 270 and midwifery 130) disregarding the first year students. a simple randomized sample size (n = 109) was determined, based on sampling formula and according to attrition rate 35%. total of 170 questionnaires were distributed among the subjects. from 170 respondents, 115 nursing and midwifery students, studying at different years of their education, completed the questionnaire yielding a response rate of 67.6%. fortunately, respondent rate was in a range that did not interfere with the sample size. to ensure that the students had reasonable familiarity with university life, we selected those students who had already completed at least two semesters of school to participate in the study. in this descriptive study, the items in the questionnaire were based on faculties common unethical behaviors in our context in three domains : educational domain (eight items), individual domain (eighteen items) and organizational domain (1 item). the items which were identified as confusing, irrelevant, or lacking variability were modified. the reliability of the questionnaire was tested through a pilot study on a sample of 55 students and cronbach - alpha was obtained as 0.92. the participants were asked to anonymously rate the occurrence of the instructors unethical behaviors in their academic activities in the questionnaire on a five - point likert - style scale including the options of (1 = almost never, 2 = seldom, 3 = do not know / not sure, 4 = frequently, and 5 = almost all times), and give information about their age, sex, and type of nursing program in which they were enrolled. for every item, 5 = almost all times option was important, and as a result, this option was reported. the data were collected by the researcher personally in a period of 2months from november to december of 2008. data collection from each classroom was performed at the beginning of the class sessions with the permission of the instructors. moreover, data analysis was performed by obtaining descriptive statistics, frequencies and percentages for sample characteristics, and measuring the students responses to the questionnaire items indicating the students views of their faculties unethical behaviors. the differences in the mean scores of two groups (nursing and midwifery students) were determined using independent t - test. the purpose of the study was explained to the students at the beginning of the study. it was emphasized that participation in the research study was voluntary and the students confidentiality was guaranteed. consent for participation was confirmed by the subjects acceptance to fill out the questionnaire, as was clarified in the cover letter. the purpose of the study was explained to the students at the beginning of the study. it was emphasized that participation in the research study was voluntary and consent for participation was confirmed by the subjects acceptance to fill out the questionnaire, as was clarified in the cover letter. this descriptive study aimed to evaluate the occurrence rate of unethical behaviors among the students faculties. the majority (88.7%) of the samples were females as compared to 11.3% of males. among the 115 students who answered the questionnaires, 61 were nursing students (53%) and 54 were midwifery students (47%). first, we examined the frequency distributions for each of the 27 items rated by students ranging from almost never to almost all times. mean scores and standard deviations for almost never and frequently items were calculated to determine the occurrence ranking of unethical behaviors. in the mean scores, the highest mean score implied most unethical behaviors, whereas the lowest mean score implied least unethical behaviors. the four behaviors had a high frequency and the highest mean score [table 1 ]. ratings of four items of faculties unethical behavior as reported by the students (highest frequently) this study showed nursing and midwifery students perception of the occurrence and rating of unethical behaviors in their instructors in the mentioned school we surveyed. we found that the majority (17 items) of the instructors unethical behaviors rated by the students were deemed to happen less frequently. on the other hand, the study results indicated that delaying in announcing the exam results, lack of creating a positive learning environment, failure to keep regularly scheduled office hours / appointments, and failure to update lecture notes when teaching a course were top - rated instructors unethical behaviors. where plagiarism, data falsification, violations of confidentiality, accepting money from students, abusing organizational resources, treating others differently on the basis of sexual orientation, refereeing with bias, and intimate relationships with students were found to be unethical. in another study, kuther (2003) studied the ethical behaviors of professors from the viewpoint of college students. she used a five - point likert - style scale ranging from : 1 = unethical under any circumstances to 5 = ethical under all circumstances. the behaviors which were viewed as most unethical were : teaching while under the influence of cocaine or other illegal drugs (mean = 0.13), insulting or ridiculing a student in his / her absence (mean = 1.21) ; telling colleagues confidential disclosures made by a student (mean = 1.29) ; insulting or ridiculing a student in the student 's presence (mean = 1.31) ; ignoring strong evidence of cheating (mean = 1.43) ; and ignoring strong evidence of plagiarism in a written assignment (mean = 1.47). in the same line, savage. (2006) showed that 42% of the respondents indicated experiences of their instructors insulting a student in front of others and 33% mentioned experiences of their instructors expecting a gift from the students at the end of their clinical practice. (2005) found that fairness in grading was the critical factor that many students use in determining whether a professor was ethical or unethical. furthermore, schmitz and schaffer (1995) as well as schaffer and juarez (1993) found that students perceived nursing faculty to be unfair and uncaring ; similarly, theis (1988) showed that the participants most frequently reported concerns of lack of respect by the instructors. including a material on a test which was not covered in the lectures or assigned reading this is an important ethical behavior that the faculties consider to give test on the materials they assign for the students and our faculties tried to do it. in a study conducted by keith - spiegel. (1993), the students reported that their instructors in their undergraduate education were ethical in their interactions with the students. the findings of the current study revealed no statistically significant difference between nursing and midwifery students responses. although the nursing students rated four frequently unethical behaviors more than the midwifery students, data analysis revealed no statistically significant differences between nursing and midwifery student 's responses in this regard. among the four top - rated unethical behaviors, delaying in announcing the exam results was rated as the first unethical behaviors by both study groups. in our college, nursing and midwifery faculties train students in the morning in the clinical settings and teach theoretical classes in the evening during the week and they have a great number of responsibilities. therefore, they are not in their office most of the time and they had better inform the students when and how they can have access to them. overall, the findings suggest that nursing and midwifery students had experienced their instructors delaying in announcing the exam results. it seems that the faculties are very busy and do not have enough time for timely delivering the exam results. one of the limitations of this study was that we only assessed the students at one college and consequently, our results may not be representative of other colleges. another limitation of this study was that the conclusions were based on the students estimation of the events as opposed to a direct measure of the actual activities. our goal is most importantly helping the instructors be aware of the situations which they may commit unethical behavior and help guide them in managing or avoiding those situations. the findings of this study suggest that greater emphasis should be put on the faculties being accessible for the students to seek help from them out of the class time, performing their grading duties in a timely manner, and creating a positive learning environment. one of the limitations of this study was that we only assessed the students at one college and consequently, our results may not be representative of other colleges. another limitation of this study was that the conclusions were based on the students estimation of the events as opposed to a direct measure of the actual activities. our goal is most importantly helping the instructors be aware of the situations which they may commit unethical behavior and help guide them in managing or avoiding those situations. the findings of this study suggest that greater emphasis should be put on the faculties being accessible for the students to seek help from them out of the class time, performing their grading duties in a timely manner, and creating a positive learning environment. overall, the data from the current sample supported to the idea that nursing professors seldom behaved unethically in most of their interactions with the students. of course, educators need to take steps toward eliminating these rare unethical behaviors toward the students and we look forward to the continued research and presentation of this important topic. we invite questions or comments which may be directed to either author. by having students learn and understand ethics in college it is hoped that this study will contribute to the growing body of knowledge about how the faculties should behave and teach the students. | background : although nursing faculties may believe that they possess a core of knowledge about ethical interactions with students, they may unwittingly risk crossing an ethical boundary in the learning environment. the ethical dimension in education exists because the instructor has authority to contribute to or impede the students acquisition of knowledge. therefore, this study aimed to determine the views of iranian baccalaureate nursing and midwifery students regarding the occurrence rate of their faculties unethical behaviors.materials and methods : in this study, 115 subjects, including 61 nursing and 54 midwifery students, completed a questionnaire (response rate = 67.6%). the questionnaire consisted of demographic data and 27 short statements which described the faculties unethical behaviors. reliability of instrument was confirmed (0.92) using cronbach-alpha.results:delaying in announcing the exam results (40%), lack of a positive learning environment (35.7%), failure to keep regularly scheduled office appointments (35.7%), and failure to update lecture notes when teaching a course (31.3%) were reported by the students as the main faculties unethical behaviors. data analysis confirmed that there were no statistically significant differences between nursing and midwifery students responses (the two - tailed t - test was not significant at alpha 0.05 levels ; p > 0.05).conclusion : the study findings suggest that more emphasis should be put on faculties being accessible for consultation out of class time, announcing the exam results in a timely manner, and creating a positive learning environment. |
from a functional perspective, the swallowing process is composed of 3 phases, namely the oral, pharyngeal, and esophageal phases. in general, dysphagia caused by neurological disorders the pharyngeal phase is defined as the process from pharyngeal swallowing to complete passage of food boluses through the upper esophageal sphincter. in cases of epiglottal folding, the closure of the vocal cord and laryngeal vestibule is incomplete in the esophageal phase ; thus, aspiration or penetration, which is the passage of food boluses through the pharynx, can occur. thus, in order to prevent aspiration pneumonia and achieve safe swallowing, optimum intervention strategies that consider the symptoms of dysphagia are required. especially, as unlike stroke, neurodegenerative diseases such as parkinson s disease worsen dysphagia with disease progression, regular diagnosis and rehabilitation are required for the rest of the patient s life. hence, for successful rehabilitation of swallowing function in parkinson s disease, a transdisciplinary approach is critical, in which physicians, nurses, physical therapists, speech pathologists, and nutritionists make decisions in a cooperative manner1. compensation techniques such as postural techniques and maneuver have been generally conducted as swallowing rehabilitation interventions2. these compensation techniques (e.g., postural techniques) have been verified to be significantly effective for the enhancement of swallowing function by many studies3, 4. recently, expiratory muscle strength training (emst) was reported to be effective for swallowing rehabilitation in patients with parkinson s disease5, 6. emst is a treatment intervention for patients with functional disorders of the respiratory system that are caused by weakening of respiratory muscles. it not only enhances respiratory functions but also postpones the outbreak of complications of the respiratory system5. the respiratory system is composed of the respiratory tract, lungs, expiratory muscles, and thoracic cage, and plays a role in the inhalation of oxygen from the air and exhalation carbon dioxide produced by energy metabolism7. in particular, both inspiration and expiration are performed by the movements of the diaphragm, respiratory muscles, and thoracic cage. inspiration is performed by active movement, while expiration is performed by passive elastic recoil8. the elderly generally not just emit less amount of air because of decreased lung capacity but also have to inspire more often to supply adequate amount of oxygen for the body7. in addition, in old age, the possibility of ultimate decline in the function of closure of the vocal cord is high owing to crevice in the larynx or distinct glottal arrowhead, which is the bending of the vocal cords9. as structural changes such as these can have adverse effects on the swallowing function in old age, strengthening of respiratory function in swallowing rehabilitation is crucial10. especially in patients with parkinson s disease, respiratory problems stand out because of gradual rigidity of expiratory muscles11. with the progression of parkinson s disease, the movements of the diaphragm and abdominal muscles become abnormal12, which eventually affects both expiration and inspiration13. therefore, strengthening of the expiratory muscle is required for optimum swallowing rehabilitation. nevertheless, studies on the respiration in parkinson s disease have mainly focused on the characteristics of respiration in the disease14, while only a few studies have been conducted on the relationship between the strengthening of expiratory muscle and swallowing function. this study investigated the effect of simultaneous application of postural techniques and emst on the enhancement of the swallowing function of patients with dysphagia caused by parkinson s disease. the participants of this study were 33 patients with dysphagia caused by parkinson s disease who attended the rehabilitation departments of 2 general hospitals in seoul and inchon between september 2014 and february 2015. the criteria for subject selection were as follows : first, those who had aspiration or penetration discovered in the pharyngeal phase ; second, those without problems in the oral phase, such as chewing ; third, those without respiratory diseases such as pneumonia or asthma ; fourth, those without cognitive problems with mini - mental state examination - korean version scores of>24 ; fifth, those who can communicate ; sixth, those without facial paralysis ; seventh, those without moderate or severe hypertension (systolic hypertension of 160 mm hg and diastolic hypertension of 100 mm hg). this study was approved by the institutional review board and was conducted in accordance with the ethical standards of the declaration of helsinki. the subjects were given sufficient explanation regarding the purpose and experimental method of this study before participation and provided voluntary consent. all the subjects were randomly assigned into a emst - only (n=18) and a postural techniques plus emst group (n=15) by using the table of random numbers. the characteristics of the participants are presented in table 1table 1.characteristics of the study participantsvariablesemst (n=18)emst+pt (n=15)age (years)63.8 8.265.1 9.5gender, n (%) male16 (88.8)15 (100)female2 (11.2)0 (0)h - y stage, n (%) 315 (83.3)11 (73.3)>43 (16.7)4 (26.7)vfs35.1 13.533.5 12.8data are presented as mean sd. emst : expiratory muscle strength training ; pt : postural techniques ; h - y stage : hoehn and yahr stage ; vfs : functional dysphagia scale based on videofluoroscopic studies emst : expiratory muscle strength training ; pt : postural techniques ; h - y stage : hoehn and yahr stage ; vfs : functional dysphagia scale based on videofluoroscopic studies postural techniques were conducted in the order of chin tucking, head rotation, head tilting, bending head back, and lying down straight for 30 minutes per session and 5 days a week for 4 weeks15, 16. emst 150 (aspire products, gainsville, usa) was used as the emst device. by referring to preceding studies6, the procedure was conducted as follows : first, in order to block air passage through the nasal cavity of the subject, the nasal cavity was closed by tweezers ; second, the subject held a mouthpiece in the mouth, and performed inspiration and expiration as fast and strong as possible through the oral cavity ; third, after performing maximum inspiration followed by maximum expiration 8 times in succession, the subject rested for 30 seconds ; fourth, this procedure was conducted for 20 minutes. by referring to preceding studies, the threshold value of resistance of emst was set at 75% based on maximum expiratory pressure. emst was conducted 20 minutes a day and 5 days a week for 4 weeks. swallowing recovery was assessed by rehabilitation physicians who did not participate in the study by using the functional dysphagia scale and based on videofluoroscopic studies (vfs)17. the vfs scale is used to identify overall swallowing problems such as aspiration observed in videofluoroscopic swallowing studies (vfss) and is composed of a total of 100 points. the higher the vfs scale score, the more severe the problem in swallowing function. at the time of its development, the vfs test had a sensitivity of 8281% and a specificity of 70.792%17. for analysis, first, a preliminary homogeneity test was conducted with the independent sample t test or chi - square test and, second, pre - post efficiency test was conducted with a paired - sample t test. chicago, il, usa) was used for the analysis, with a significance level of 0.05. the results of the independent t test and chi - square test for homogeneity of age, gender, y - h stage, and mean vfs scale scores in the emst - only and combined intervention groups indicated no significant difference in all the items (table 1). the result of the paired t test showed a decrease in mean vfs scale score for both groups after the treatment. the decrease in the combined intervention group was significantly greater than that in the emst - only group (table 2table 2.results of the assessment using the vfs based on videofluoroscopic studiestestemst (n=18)emst+pt (n=15)baseline35.1 13.533.5 12.8post - training 22.5 11.316.2 8.1p<0.05). in this study, emst significantly enhanced the swallowing function of dysphagia caused by parkinson s disease. like this study, preceding studies verified the enhancement of swallowing functions, such as reduction of aspiration and opening of the upper esophageal sphincter that result from emst for patients with parkinson s disease6. the suprahyoid muscle protects the airway by raising the hyoid bone and plays the role of supporting safe swallowing by the opening cricopharyngeus muscle. dysphagia caused by neurological problems such as parkinson s disease weakens the suprahyoid and cricopharyngeus muscles. emst was verified to enhance the pharyngeal swallowing function by strengthening swallowing muscles such as the suprahyoid muscle18. in this study, the combined intervention group had a significantly higher enhancement of swallowing function than the emst - only group, which is deemed to be the result of the synergic effect of the two treatment modalities. postural techniques such as lowering the chin are performed to complement structural and physiological defects by changing the direction of food boluses going down or the area of the pharynx by adjusting posture rather than strengthening the muscles themselves1. these postural techniques have been reported to be effective for the swallowing rehabilitation of patients with dysphagia who have limited movements of the tongue base or have weakened laryngeal raise2. on the other hand, emst is a muscle training method that uses resistance and is effective for vitalization of swallowing muscles and raising the larynx18. in summary, simultaneous application of postural techniques and emst is presumed to have a stronger effect on the enhancement of swallowing function by complementing safe swallowing and strengthening of swallowing muscles. in order to investigate the vitalization of the swallowing muscles in greater detail, studies that use surface electromyography the limitations of this study are as follows : first, as the number of subjects was small, generalization of the study results is difficult. second, as most of the subjects were male patients, analysis of treatment effects according to gender is required in the future. studies that analyze the effect of the intervention duration of emst and postural techniques are required in the future. the results of this study imply that simultaneous performance of postural techniques and emst is more effective than emst alone when applied in the swallowing rehabilitation for patients with dysphagia caused by parkinson s disease. | [purpose ] this study aimed to investigate the effect of simultaneous application of postural techniques and expiratory muscle strength training on the enhancement of the swallowing function of patients with dysphagia caused by parkinson s disease. [subjects and methods ] the subjects of this study were 18 patients who received simultaneous application of postural techniques and expiratory muscle strength training and 15 patients who received expiratory muscle strength training only. postural techniques were conducted in the order of chin tucking, head rotation, head tilting, bending head back, and lying down, while expiratory muscle strength training was conducted at a resistance level of about 70% of the maximal expiratory pressure. swallowing recovery was assessed by using the functional dysphagia scale based on videofluoroscopic studies. [results ] the mean value obtained in the videofluoroscopic studies for both groups decreased after the treatment. in the postural techniques plus expiratory muscle strength training group, the decrease was significantly greater than that in the expiratory muscle strength training - only group. [conclusion ] the results imply that simultaneous performance of postural techniques and expiratory muscle strength training is more effective than expiratory muscle strength training alone when applied in the swallowing rehabilitation for patients with dysphagia caused by parkinson s disease. |
increased rate of depression among individuals with rheumatoid arthritis (ra) in comparison with the general population has been described previously (1, 2). it has also been shown that depression can be associated with reduced health - related quality of life (3) and weakness (4) in patients with ra, which leads to poorer long - term outcomes (5). it is essential to target and treat depression since increased mortality rate has been reported in depressed subjects with ra (6). although the association between depression and ra has been demonstrated in previous studies, there are conflicting results in the prevalence of depression in ra. since there are various factors that affect incidence of depression, including socioeconomics condition and familial support, observing different prevalence rates among different nations can be expected. until now, no investigation has been performed to estimate the prevalence of depression among iranian patients with ra. before implementation of any kind of intervention to target depression, it is essential to know the background condition and prevalence of depression in a specific population. the reported estimation of depression prevalence in ra has a wide range from 9.5% to 41.5% (7). therefore, it is necessary to estimate the prevalence of depression in each population separately. to understand the impact of depression on ra. rheumatoid arthritis is a chronic multifactorial inflammatory disease, which primarily affects joints (8) and is associated with pain and weakness. it is characterized by joint swelling, morning stiffness and disability (9). since ra is a chronic condition, it should be taken into consideration that cumulative risk of depression and also intermittent recurrences can occur (10, 11). another reason for existence of conflicting reports in prevalence of depression in ra is the usage of different assessment tools (1). prevalence of depression has been reported much higher in studies using self - report measures (12). however, a higher rate of depression among patients with ra has been often observed in comparison with the general population (13). the aim of this study was to evaluate the prevalence of depression among iranian patients with ra using beck s depression inventory ii (bdi ii), and to compare it with healthy subjects. the effect of pain, weakness and rheumatoid factor (rf) status on depression was also assessed. we investigated patients with ra, who were referred to rheumatology clinics of kermanshah university of medical sciences in a descriptive cross - sectional study. the study was approved by the research ethics committee of kermanshah university of medical sciences. patients with ra, who were referred to rheumatology clinics, were entered in this study. exclusion criteria were : previous history of other chronic diseases (such as diabetes, hypertension, collagen vascular disorders, hypo - or hyperthyroidism, metabolic disorders, and etc.), addiction to illegal drugs, and smoking and alcohol consumption. the sampling method was based on selection of participants according to the inclusion and exclusion criteria. age, marital status, educational level and occupation were asked directly from the participants and were indexed in pre - prepared forms. existence of pain and weakness was assessed subjectively by patients self - report to yes / no questions. beck s depression inventory ii is a self - report measurement for depression, which consists of 21 items in two subscales (14). each of the 21 items corresponds to a symptom of depression and is summed to give a single score for bdi ii. there is a four - point scale for each item ranging from 0 to 3. on two items (16 and 18) there are seven options to indicate either an increase or decrease of appetite and sleep. total score of 0 - 13 is considered in the minimal range, 14 - 19 indicates mild depression, 20 - 28 shows moderate, and 29 - 63 illustrates severe depression. the persian version of this questionnaire has been validated and its high internal consistency (cronbach s alpha = 0.87) and validity (r = 0.74) have been demonstrated (15). all statistical analysis was performed using spss software version 18 (spss, inc., categorical variables were expressed with frequency, and continuous variables were described with mean standard deviation. chi - square test was used to compare prevalence of depression between the two groups. comparison of means was performed using independent t - test and one - way analysis of variances (anova). we investigated patients with ra, who were referred to rheumatology clinics of kermanshah university of medical sciences in a descriptive cross - sectional study. the study was approved by the research ethics committee of kermanshah university of medical sciences. patients with ra, who were referred to rheumatology clinics, were entered in this study. exclusion criteria were : previous history of other chronic diseases (such as diabetes, hypertension, collagen vascular disorders, hypo - or hyperthyroidism, metabolic disorders, and etc.), addiction to illegal drugs, and smoking and alcohol consumption. the sampling method was based on selection of participants according to the inclusion and exclusion criteria. age, marital status, educational level and occupation were asked directly from the participants and were indexed in pre - prepared forms. existence of pain and weakness was assessed subjectively by patients self - report to yes / no questions. beck s depression inventory ii is a self - report measurement for depression, which consists of 21 items in two subscales (14). each of the 21 items corresponds to a symptom of depression and is summed to give a single score for bdi ii. there is a four - point scale for each item ranging from 0 to 3. on two items (16 and 18) there are seven options to indicate either an increase or decrease of appetite and sleep. total score of 0 - 13 is considered in the minimal range, 14 - 19 indicates mild depression, 20 - 28 shows moderate, and 29 - 63 illustrates severe depression. the persian version of this questionnaire has been validated and its high internal consistency (cronbach s alpha = 0.87) and validity (r = 0.74) have been demonstrated (15). all statistical analysis was performed using spss software version 18 (spss, inc., categorical variables were expressed with frequency, and continuous variables were described with mean standard deviation. chi - square test was used to compare prevalence of depression between the two groups. comparison of means was performed using independent t - test and one - way analysis of variances (anova). a total of 171 patients in the ra group and 198 subjects in the control group participated in this investigation. mean age in ra and control group was 42.05 11.22 and 41.36 10.77 years old. the majority of participants in both groups were female (123 (62.1%) in the ra group and 108 (63.2%) in the control group). most subjects in both groups were also married (71.2% and 77.2% in the ra and control groups, respectively). only 17.7% of patients in the ra group (n : 35) and 19.9% of participants in the control group (n : 34) were living in villages. there were no significant differences in the demographic features between the two groups (table 1). one hundred and three participants (52%) in the control group and 30 patients (29.2%) in the ra group had minimal range of bdi ii score whereas 29 patients in the ra group (17%) and 20 healthy subjects (10.1%) revealed severe depression (table 1). in the ra group, 45.7% of patients revealed some extent of depressive mood whereas this estimation was 32.8% in the control group (p = 0.008). abbreviation : ns, not significant significance at the level of p < 0.01 ; chi - square test was used to compare the prevalence of each category between groups. mean bdi ii score was significantly higher in the ra group in comparison with the control group (15.53 11.04 and 19.26 10.06 in the control and ra groups, respectively ; p = 0.001). similar results were obtained when we compared the mean scores of bdi ii between each gender separately (table 2). mean bdi ii score was 18.49 8.56 and 14.66 10.97 among males in ra and control group, respectively (p = 0.026). similarly female participants in the ra group obtained higher scores than healthy subjects (19.71 10.85 and 16.05 11.09 in the ra and control groups, respectively ; p = 0.012). although there was a significant difference in bdi ii scores between these two groups among participants younger than 50 years old, patients with ra, who were older than 50 years showed significantly higher bdi ii scores in comparison with healthy subjects (21.11 9.36 and 16.48 11.6 in ra and control groups, respectively ; p = 0.036) (table 2). abbreviation : sd, standard deviation. significance at the level of p < 0.05 ; independent t - test was used to compare means between groups. severity of depression detected by bdi ii was significantly higher among males and females with ra. minimal range of bdi ii score was detected in 34 females with ra (31.5%) and 62 healthy females (50.4%), whereas 21 females with ra showed severe depression (19.43%) while the prevalence of severe depression among healthy females was only 12 (9.75%) (p = 0.016). significance at the level of p < 0.05 ; significance at the level of p < 0.01. p - value stands for chi - square test to evaluate prevalence between categorical groups. in the ra group, 154 (90.1%) mentioned that they were feelings of pain and only 17 patients (9.9%) expressed having no pain. similarly, 149 (87.2%) felt weakness and 22 (12.8%) did not complain from weakness. no significant association was found between existence of pain and weakness and score of bdi ii (p = 0.14 and 0.19, respectively). rheumatoid factor (rf) was positive in the majority of patients (87.7%). positive rf status was associated with lower scores of bdi ii whereas patients with negative rf status were significantly more susceptible to severe depression (p = 0.001). among patients that had positive rf status, 33% had minimal, 25% had mild, 28% had moderate and only 12.8% had severe depressive mood. among patients with negative rf status, 43% had severe depression and no case of minimal range of bdi ii these results show that positive rf can be a preventive factor for depression among patients with ra. in the present study, the prevalence of depression was assessed in patients with ra and was compared with a group of healthy subjects., we reported that 17% of iranian patients with ra had severe depression, which is significantly higher than healthy individuals. higher level of mood deterioration in patients with ra in comparison with the general population has been reported, previously (1, 2). the role of social support (16) and socioeconomic status (17) has been described by zyrianova. (17), studies of whom demonstrated that higher rate of depression in ra is associated with lower socioeconomic status and social support, which insists on the fact that the prevalence of depression may vary in different countries in which patients receive different levels of social support. to the best of our knowledge, this is the first investigation assessing the prevalence and impact of depression among iranian patients with ra. our study showed higher prevalence of depression and higher rate of severe depression among patients with ra regardless of gender. however, older patients (older than 50 years old) showed more depressive signs than healthy subjects at a similar age, which is in line with the report of matcham. (1). however, matcham also explained that this higher rate of depression in elderly might exist regardless of presence of ra, since increased risk of depression in the elderly has been described previously (18). in this regard, our study showed that elderly patients with ra are more depressed than healthy subjects at a similar age. in fact, old age, which is an independent determinant of depression, affects patients with ra more considerably than the normal population. in line with our results, dickens. (19) reported that depression is more common in patients with ra than in healthy individuals. however, dickens proposed that this difference is not due to socio - demographic differences between groups. moreover in their meta - analysis the role of various methods of assessing depression in differences among studies, examining the levels of depression in patients with ra, was described. similarly, matcham. (1) showed that depressive symptoms were present in 38.8% of subjects using the patient health questionnaire phq-9, and in 14.8% to 48% of subjects using the hospital anxiety and depression scale (hads). here we used the beck depression inventory ii to determine depression among patients with ra. according to our results, 45% of patients with ra showed some extent of depressive mood (28% moderate and 17% severe depression). the relative difference between our report and previous literature can be due to variations in the measurement tools. (21) demonstrated the role of disease acceptance in the association between pain and depression in ra. their study illustrated that patients with higher acceptance had slower growth rates of depression across time, even when pain increased. this finding showed that acceptance is a confounder in the correlation between pain and depression. here, we found no association between pain and bdi ii score, which may be due to the existence of such confounders. previously, wolfe and michaud showed that weakness is a dominant predictor of self - reported depression in ra (10). one reason for these conflicting results can be differences in weakness of the measurement tool. although all these investigations have assessed weakness through patients subjective self - report, variation in assessment tools can cause such conflicts in the outcomes. age, duration of ra and existence of other comorbid conditions are probable confounders that may affect the linear relationship between weakness and depression in ra. previously, tillmann. reported that the rf - subtype is associated with higher incidence of depression (23), which is in line with our results. previous literature has linked rf negative status to the covariates of depression, such as psychiatric disorders anxiety and neuroticism (24 - 26). furthermore, rf negative status has been associated with lower self - acceptance, somatization complaints and obsessive - compulsiveness (27, 28). all these studies, including our investigation, have proposed rf negative status as an available biomarker, which may be clinically linked to higher psychopathy. here, we found that depression is more common among iranian patients with ra than healthy subjects and is estimated to be 45% (p = 0.008). the higher rate of depression exists among patients with ra regardless of gender but it has a significant association with older age (p = 0.03). here, we found that depression is more common among iranian patients with ra than healthy subjects and is estimated to be 45% (p = 0.008). the higher rate of depression exists among patients with ra regardless of gender but it has a significant association with older age (p = 0.03). | backgroundincreased prevalence of depression among patients with rheumatoid arthritis (ra) has been described previously. however, the impact of depression among iranian patients has not yet been investigated.objectiveshere, the prevalence of depression was assessed and the effect of disease - related characteristics including pain, weakness and rheumatoid factor (rf) status on incidence of depression was evaluated.materials and methodspatients with ra, who were referred to rheumatology clinics of kermanshah university of medical sciences and healthy subjects from the general population of kermanshah participated in this investigation. depression was assessed using beck s depression inventory ii (bdi ii). pain and weakness were assessed subjectively by patients self - report. data was collected during a year between 2012 and 2013. chi - square test and independent t - test were used.resultsone hundred and seventy - one patients with ra and 198 healthy individuals participated in this investigation. in the ra group, depressive mood was detected in 45.7% of patients, which was significantly higher than healthy subjects (p = 0.008). depression was more common in elderly patients (> 50 years old) in comparison with healthy subjects at a similar age (p = 0.03). pain and weakness had no influence on depression incidence (p = 0.14 and 0.19, respectively) whereas patients with negative rf status were significantly more susceptible to severe depression (p : 0.001).conclusionsdepression is more common among iranian patients with ra (45%) than healthy subjects regardless of gender. depression has a significant association with older age. negative rf status may predict future risk of depression. |
patients with advanced fecd (modified krachmer grade 5 or 6) requiring corneal transplantation and control participants without guttae (grade 0) were enrolled in a mayo clinic institutional review board - approved hereditary eye disease study. fecd grade was established by slit lamp biomicroscopy using specular reflection techniques by one of the authors (khb, ljm, or svp). in control participants, patients enrolled in the study agreed to a blood draw and use of their approximately 8-mm - diameter central ce / descemet membrane specimen obtained at endothelial keratoplasty for fecd. dna was isolated from peripheral blood leukocytes, and rna was isolated from ce / descemet membrane specimens following storage in rnalater ice (thermo fisher scientific, waltham, ma, usa). endothelial tissue from control subjects was obtained at the time of keratoplasty for non - fecd disease or from eyes with normal anterior segments at the time of enucleation. total rna was isolated independently from 16 tissue samples (12 fecd and 4 controls) by homogenization in qiazol lysis reagent, chloroform extraction and rneasy mini qiacube kit (qiagen, valencia, ca, usa). rna libraries were prepared for each tissue sample, using the truseq rna sample prep kit version 2 (illumina, san diego, ca, usa). all samples had rna integrity number (rin) values of 6.0. for truseq stranded total rnaseq, ribosomal transcripts were depleted from total rna, using ribo - zero gold rna removal kit followed by replacement of deoxythymidine triphosphate (dttp) with deoxyuridine triphosphate (dutp) during reverse transcription in the second strand synthesis, using truseq stranded total library preparation kit. the resulting libraries were minimally amplified to enrich for fragments using adapters on both ends and then quantified for sequencing at three samples / lane by using a hiseq4000 (illumina) sequencer. for that set of samples, poly(a) mrna was isolated before library preparation using oligo(dt) magnetic beads. whole transcriptomic sequencing data from each tissue sample was analyzed using a comprehensive computational program called the mayo analysis pipeline for rna sequencing (map - rseq) (mayo clinic, rochester, mn, usa) to align, assess, and deliver multiple genomic features. map - rseq uses a variety of freely available bioinformatics tools along with in - house developed methods to obtain in - depth quality control data, transcriptome read alignment, abundance of gene expression, exon expression, and other transcriptomic features. the binary alignment map files from map - rseq were analyzed using mixture of isoforms (miso) software (massachusetts institute of technology, cambridge, ma, usa) that quantitates the expression level of alternatively spliced genes between groups. for pairwise comparisons, miso calculates bayesian probabilities that there is a genuine difference in the splicing of a given exon between two samples. to establish a differential gene database, we used stringent filtering criteria within miso (fig. 1) to perform genome - wide pairwise comparisons among 11 fecd samples with tnr expansions and 4 controls (44 total comparisons) using reads to support isoform 1 (inclusive exon) > 2 ; reads to support isoform 2 (exclusive exon) > 2 ; sum of inclusive and exclusive reads of 25 ; percentage of spliced in (psi) changes > 0.2 ; and bayes factor > 50 as the user - defined criteria for the comparisons. for psi, miso calculates a value for every differential splicing event, providing a range from 0 to 1, with 0 being completely excluded and 1 being uniformly included in the splicing products. visualization of alternatively spliced genes was generated using sashimi plots from the integrated genomics viewer. the single fecd sample without repeat expansion was not included in this pairwise comparison. the differential gene database was compared with a similar database generated from a pilot study of 8 ce specimens from a study group consisting of 4 fecd patients with ctg tnr expansions in the tcf4 gene, 1 fecd patient without a ctg tnr expansion, and 3 control patients, which allowed twelve pairwise comparisons between fecd with tnr expansion and controls. initial lists of candidate differential splicing events were produced by miso using stringent criteria (see methods). these lists were filtered to retain only those events which occurred in more than half of the pairwise comparisons between fecd samples and controls, yielding a combined total of 101 events from the two data sets. twenty - four validated events present in both data sets are detailed in table 2. demographic, clinical and ctg trinucleotide repeat length for study participants summary of differential gene splicing events present in at least 50% of both pilot and pairwise comparisons preparation of cdna by reverse transcription (rt - pcr) and analysis by agarose gel electrophoresis was described previously. specific primers for each validation assay and pcr conditions are provided in supplementary table s1. briefly, leukocyte - derived dna was extracted using autogen flexigene (qiagen) and resuspended in 1 tris - edta (te) buffer for a final concentration of 250 ng/l. tnr repeats from each sample were amplified by pcr, using an i - cycler (bio - rad, hercules, ca, usa) by placing 100 ng of genomic dna with 10 pmol of oligonucleotide primers specific for tcf4 (5-tcf - fuchs ' : 5-cagatgagtttggtgtaagatg-3 ; and 3-tcf - fuchs ' 1 : 5-acaagcagaaagggggctgcaa-3) in the presence of platinum pcr super mix high fidelity (invitrogen, carlsbad, ca, usa). the pcr program consisted of 100 ng of genomic dna and 10 pmol of each primer in 50 l of hot start (invitrogen) at 95c for 6 minute for 1 cycle, then 95c for 1 minute for 1 cycle, then 62c for 1 minute, followed by 68c for 3 minute for 35 cycles, and then 68c for 1 cycle for 7 minute, followed by a 4c hold. for short tandem repeat analysis, a 5fam primer (5-fam - tcf - fuchs ' : 5-cagatgagtttggtgtaagatg-3) was used in place of 5-tcf - fuchs ', and pcr after pcr amplification, 2 l of dna was mixed with 12 l of diluted map marker 1000 (bio ventures, inc., gene scan was carried out using 3730xl dna analyzer (abi, foster city, ca, usa). gene sets identified by filtering miso results were analyzed for overrepresentation of genes in specific panther system (in the public domain, http://www.pantherdb.org/) families and pathways, using the default settings of the panther web portal. specifically, panther system overrepresentation test (release date 7/15/2016), annotation version, gene ontology (go) database (released 08/22/2016 ; in the public domain, http://www.geneontology.org), and homo sapiens reference lists were used. bonferroni correction for multiple comparison testing was performed to determine significance (p 2 ; reads to support isoform 2 (exclusive exon) > 2 ; sum of inclusive and exclusive reads of 25 ; percentage of spliced in (psi) changes > 0.2 ; and bayes factor > 50 as the user - defined criteria for the comparisons. for psi, miso calculates a value for every differential splicing event, providing a range from 0 to 1, with 0 being completely excluded and 1 being uniformly included in the splicing products. visualization of alternatively spliced genes was generated using sashimi plots from the integrated genomics viewer. the single fecd sample without repeat expansion was not included in this pairwise comparison. the differential gene database was compared with a similar database generated from a pilot study of 8 ce specimens from a study group consisting of 4 fecd patients with ctg tnr expansions in the tcf4 gene, 1 fecd patient without a ctg tnr expansion, and 3 control patients, which allowed twelve pairwise comparisons between fecd with tnr expansion and controls. initial lists of candidate differential splicing events were produced by miso using stringent criteria (see methods). these lists were filtered to retain only those events which occurred in more than half of the pairwise comparisons between fecd samples and controls, yielding a combined total of 101 events from the two data sets. twenty - four validated events present in both data sets are detailed in table 2. the full set of 101 events is provided in supplementary table s2. demographic, clinical and ctg trinucleotide repeat length for study participants summary of differential gene splicing events present in at least 50% of both pilot and pairwise comparisons preparation of cdna by reverse transcription (rt - pcr) and analysis by agarose gel electrophoresis was described previously. specific primers for each validation assay and pcr conditions are provided in supplementary table s1. briefly, leukocyte - derived dna was extracted using autogen flexigene (qiagen) and resuspended in 1 tris - edta (te) buffer for a final concentration of 250 ng/l. tnr repeats from each sample were amplified by pcr, using an i - cycler (bio - rad, hercules, ca, usa) by placing 100 ng of genomic dna with 10 pmol of oligonucleotide primers specific for tcf4 (5-tcf - fuchs ' : 5-cagatgagtttggtgtaagatg-3 ; and 3-tcf - fuchs ' 1 : 5-acaagcagaaagggggctgcaa-3) in the presence of platinum pcr super mix high fidelity (invitrogen, carlsbad, ca, usa). the pcr program consisted of 100 ng of genomic dna and 10 pmol of each primer in 50 l of hot start (invitrogen) at 95c for 6 minute for 1 cycle, then 95c for 1 minute for 1 cycle, then 62c for 1 minute, followed by 68c for 3 minute for 35 cycles, and then 68c for 1 cycle for 7 minute, followed by a 4c hold. for short tandem repeat analysis, a 5fam primer (5-fam - tcf - fuchs ' : 5-cagatgagtttggtgtaagatg-3) was used in place of 5-tcf - fuchs ', and pcr was performed as described above. after pcr amplification, 2 l of dna was mixed with 12 l of diluted map marker 1000 (bio ventures, inc., gene scan was carried out using 3730xl dna analyzer (abi, foster city, ca, usa). gene sets identified by filtering miso results were analyzed for overrepresentation of genes in specific panther system (in the public domain, http://www.pantherdb.org/) families and pathways, using the default settings of the panther web portal. specifically, panther system overrepresentation test (release date 7/15/2016), annotation version, gene ontology (go) database (released 08/22/2016 ; in the public domain, http://www.geneontology.org), and homo sapiens reference lists were used. bonferroni correction for multiple comparison testing was performed to determine significance (p 45 repeats ; 45 repeats). sashimi plot showing the number of reads spanning individual splice junctions are shown next to lines connecting the exons involved. (b) rt - pcr using primers that flank selected exons was used to assess exon inclusion from ppfibp1 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). differential splicing of mbnl1 and mbnl2 is a well - characterized consequence of tnr expansion in dm1 and is routinely found in fecd as well. in addition to numa1 and ppfibp1, mbnl1 and mbnl2 transcripts were also detected as differentially spliced in all 44 comparisons in the validation data set (table 2). experimental rt - pcr validation of the mbnl1 splicing changes in fecd was presented previously. as noted for numa1 and ppfibp1, the pattern of rt - pcr products in fecd patients with tnr expansion (fig. 4a, lanes 57) is markedly different than the products from control ce specimens (fig. 4a, lanes 13) and from an fecd patient without a tnr expansion (fig. the main mbnl2 product from fecd patients with a tnr expansion was 544 bp, in contrast to control samples and the fecd sample without expansion, which had several products, all less than 500 bp. (a) rt - pcr using primers that flank selected exons was used to assess exon inclusion from mbnl2 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). (b) the structure of three splice products from the mbnl2 gene is shown. exons of the mbnl2 gene are shown as rectangles, and the length of the exon sequence included in each product is given. the structure of the three products shown in bold (544 bp, 490bp, and 395 bp) was verified by sanger sequencing. (c) the predicted protein sequence of the carboxyl terminus of two of the mbnl2 splice variants (544 and 395 bp rt - pcr variants) is shown, with regions that are common to both products in grey. the pattern of rt - pcr products from mbnl2 was complex, so we sought further verification of the identity of the three major bands. sanger sequencing of the 544-, 490-, and 395-bp bands confirmed they were from mbnl2 and also identified the presence of a 54-bp insert in the 544 band which was absent from the 490- and 395-bp products (fig. when the 544 band sequence was compared to the 395 band sequence, the 544 band contained not only the 54-bp insert but also included a 95-bp insert near the 3 end (fig. comparison of the amino acid sequences showed that the 544-bp segment had an additional 18 amino acids (aa) in frame with the comparable region in the 395-bp sequence, but the inclusion of the 95-bp insert at the 3 end of 544 changed the reading frame and the aa sequence of the c terminus of the protein (fig. one of the interesting differential splicing events listed in table 2 is the splicing of vegfa (fig. the largest product from the vegfa gene produced in the ce is 658 bp in length and includes 7 exons. this product was confirmed by sequencing to encode vegf165 (enst00000523950.5, refers to the human protein - coding splice variant) and is the preferential splicing pattern in the ce from patients with tnr expansions (fig. this isoform does contain the c - terminal heparin binding domain, which helps to anchor the protein in the extracellular matrix and promotes bioavailability. in control samples (fig. 5b, lanes 13) and in an fecd sample from a patient that did not have a tnr expansion (fig. 5b, lane 8), the product that lacks the 132-bp exon 7 is the preferential splicing pattern. this removes 44 amino acids from the vegfa protein and creates the isoform vegf121 that lacks the heparin binding domain encoded by exons 6 and 7 (fig. sanger sequencing confirmed that this product is identical to enst00000372077.8 and codes for vegf121 after removal of the 26 amino acid signal peptide (fig. (a) sashimi plot showing the number of reads spanning individual splice junctions next to lines connecting the exons involved. (b) rt - pcr using primers that flank selected exons was used to assess exon inclusion from vegfa in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). (c) the structure of two splice products from the vegfa gene is shown. exons of the vegfa gene are shown as rectangles, and the length of the exon sequence included in each product is given. the structure of the two products shown in bold (658 bp and 526 bp) was verified by sanger sequencing. thus, novel splicing events that may occur in a particular tissue or disease state were not included in the analysis. in assessing the transcripts produced from the fgfr2 gene, a novel product was identified that used a unique 5 splice junction in the eighth exon. sequencing of the rt - pcr product from an fecd sample confirmed the use of a canonical gt 5 splice site for this isoform, removing 51 bp from the 3 end of exon 8 (fig 6b). this novel splice event removed 17 amino acids from this receptor (fig 6c). the use of this 5 splice junction is more common in ce from fecd samples than in controls, and it is also seen to a lesser extent in the fecd sample from a patient that did not have a repeat expansion novel splicing event in fgfr2 transcripts in the ce (a) rt - pcr using primers that flank selected exons was used to assess exon inclusion from fgfr2 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). (b) sequence traces from the isolated upper (reference) and lower (alternative splice form) bands from figure 6a are shown. using panther overrepresentation analysis, assessment of the fecd signature differential splicing gene list within the go molecular function category showed an enrichment for genes involved in cytoskeletal protein binding (table 3). this enrichment is statistically significant (p value, 1.9 10) even after bonferroni correction for multiple comparisons. additionally, a 14.2-fold overrepresentation of genes encoding products that bind cell adhesion molecules was also identified (p value 1 10). notably, both of these categories were also overrepresented in the entire group of 101 genes identified in the combined data from the pilot and validation sets (supplementary table s2). in that larger group, there was a 7.4-fold enrichment for cell adhesion molecule binding proteins (p value 5.4 10) and a 4.2-fold enrichment for cytoskeletal binding proteins (supplementary table s3). web - based panther system biochemical pathway analysis of the top 24 differential splicing events within the go cellular component category, the genes listed in table 2 are significantly enriched for products found in the cell cortex (table 3 ; p value 2.6 10) and adherens junctions (p value 7.4 10). these enrichments are also noted in the full list of 101 genes (p value 2.2 10 and 9.1 10, respectively) (supplementary tables s2 and s3). finally, within the go biological process category, the gene list from table 2 was enriched for golgi organization (p value 1.7 10) and positive regulation of epithelial cell migration (p value 4.4 10) (table 3). neither of these enrichments was statistically significant in the full set of 101 genes (supplementary table s2). however, the larger gene set did have a notable enrichment for positive regulation of gtpase activity (p value 1.4 10) (supplementary table s3). sixty - one differential splicing events in 58 genes were identified in more than half of the 44 pairwise comparisons (11 fecd compared to 4 controls) from this validation sample set (fig. 1 ; supplementary table s2). twenty - four of these events had previously met the same filtering criteria in the pilot study, validating a broad signature of differential splicing events in fecd associated with ctg tnr expansion in the tcf4 gene. differential splicing of numa1 and ppfibp1 was identified in every fecd sample compared with normal in both the original pilot and the current validation study (table 2). for both the numa1 and the ppfibp1 events, the median psi values for the fecd samples were much lower than for the controls, indicating preferential exclusion of the target exons in fecd. these patterns are shown in figures 2a and 3a, which present sashimi plot views of the sequence data. primers that spanned the relevant splice junctions were used for rt - pcr validation of the miso - calculated differential splicing events for numa1 and ppfibp1 (figs. note that the pattern of products in figures 2b and 3b, lanes 13 (controls) favors the larger product, whereas the pattern of products in figures 2b and 3b, lanes 5 to 7 (fecd with tnr expansion) favors the smaller splice product, in agreement with the psi calculations from miso. interestingly, the same missplicing events in both numa1 and ppfibp1 were also identified in muscle cells from a mouse model of dm1 (table 2). also of interest, numa1 and ppfibp splicing products produced in the ce from a fecd patient that did not have a tnr expansion (figs. 2b, 3b, lanes 13) rather than that of fecd samples from patients that have repeat expansions (figs. (a) sashimi plot showing the number of reads spanning individual splice junctions next to lines connecting the exons involved. (b) rt - pcr using primers that flank selected exons was used to assess exon inclusion from numa1 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). sashimi plot showing the number of reads spanning individual splice junctions are shown next to lines connecting the exons involved. (b) rt - pcr using primers that flank selected exons was used to assess exon inclusion from ppfibp1 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). differential splicing of mbnl1 and mbnl2 is a well - characterized consequence of tnr expansion in dm1 and is routinely found in fecd as well. in addition to numa1 and ppfibp1, mbnl1 and mbnl2 transcripts were also detected as differentially spliced in all 44 comparisons in the validation data set (table 2). experimental rt - pcr validation of the mbnl1 splicing changes in fecd was presented previously. validation of the differential splicing of mbnl2 transcripts is shown in figure 4a. as noted for numa1 and ppfibp1, the pattern of rt - pcr products in fecd patients with tnr expansion (fig. 4a, lanes 57) is markedly different than the products from control ce specimens (fig. 4a, lanes 13) and from an fecd patient without a tnr expansion (fig. 4a, lane 8). the main mbnl2 product from fecd patients with a tnr expansion was 544 bp, in contrast to control samples and the fecd sample without expansion, which had several products, all less than 500 bp. (a) rt - pcr using primers that flank selected exons was used to assess exon inclusion from mbnl2 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). (b) the structure of three splice products from the mbnl2 gene is shown. exons of the mbnl2 gene are shown as rectangles, and the length of the exon sequence included in each product is given. the structure of the three products shown in bold (544 bp, 490bp, and 395 bp) was verified by sanger sequencing. (c) the predicted protein sequence of the carboxyl terminus of two of the mbnl2 splice variants (544 and 395 bp rt - pcr variants) is shown, with regions that are common to both products in grey. the pattern of rt - pcr products from mbnl2 was complex, so we sought further verification of the identity of the three major bands. sanger sequencing of the 544-, 490-, and 395-bp bands confirmed they were from mbnl2 and also identified the presence of a 54-bp insert in the 544 band which was absent from the 490- and 395-bp products (fig. 4a). when the 544 band sequence was compared to the 395 band sequence, the 544 band contained not only the 54-bp insert but also included a 95-bp insert near the 3 end (fig. comparison of the amino acid sequences showed that the 544-bp segment had an additional 18 amino acids (aa) in frame with the comparable region in the 395-bp sequence, but the inclusion of the 95-bp insert at the 3 end of 544 changed the reading frame and the aa sequence of the c terminus of the protein (fig. one of the interesting differential splicing events listed in table 2 is the splicing of vegfa (fig. 5). the largest product from the vegfa gene produced in the ce is 658 bp in length and includes 7 exons. this product was confirmed by sequencing to encode vegf165 (enst00000523950.5, refers to the human protein - coding splice variant) and is the preferential splicing pattern in the ce from patients with tnr expansions (fig. this isoform does contain the c - terminal heparin binding domain, which helps to anchor the protein in the extracellular matrix and promotes bioavailability. in control samples (fig. 5b, lanes 13) and in an fecd sample from a patient that did not have a tnr expansion (fig. 5b, lane 8), the product that lacks the 132-bp exon 7 is the preferential splicing pattern. this removes 44 amino acids from the vegfa protein and creates the isoform vegf121 that lacks the heparin binding domain encoded by exons 6 and 7 (fig. sanger sequencing confirmed that this product is identical to enst00000372077.8 and codes for vegf121 after removal of the 26 amino acid signal peptide (fig. (a) sashimi plot showing the number of reads spanning individual splice junctions next to lines connecting the exons involved. (b) rt - pcr using primers that flank selected exons was used to assess exon inclusion from vegfa in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). (c) the structure of two splice products from the vegfa gene is shown. exons of the vegfa gene are shown as rectangles, and the length of the exon sequence included in each product is given. the structure of the two products shown in bold (658 bp and 526 bp) was verified by sanger sequencing. thus, novel splicing events that may occur in a particular tissue or disease state were not included in the analysis. in assessing the transcripts produced from the fgfr2 gene, a novel product was identified that used a unique 5 splice junction in the eighth exon. sequencing of the rt - pcr product from an fecd sample confirmed the use of a canonical gt 5 splice site for this isoform, removing 51 bp from the 3 end of exon 8 (fig 6b). this novel splice event removed 17 amino acids from this receptor (fig 6c). the use of this 5 splice junction is more common in ce from fecd samples than in controls, and it is also seen to a lesser extent in the fecd sample from a patient that did not have a repeat expansion novel splicing event in fgfr2 transcripts in the ce (a) rt - pcr using primers that flank selected exons was used to assess exon inclusion from fgfr2 in corneal endothelial rna samples from controls (lanes 13) and fecd patients (lanes 58). the repeat expansion status of each sample is shown (+, > 45 repeats ; 45 repeats). (b) sequence traces from the isolated upper (reference) and lower (alternative splice form) bands from figure 6a are shown. using panther overrepresentation analysis, assessment of the fecd signature differential splicing gene list within the go molecular function category showed an enrichment for genes involved in cytoskeletal protein binding (table 3). this enrichment is statistically significant (p value, 1.9 10) even after bonferroni correction for multiple comparisons. additionally, a 14.2-fold overrepresentation of genes encoding products that bind cell adhesion molecules was also identified (p value 1 10). notably, both of these categories were also overrepresented in the entire group of 101 genes identified in the combined data from the pilot and validation sets (supplementary table s2). in that larger group, there was a 7.4-fold enrichment for cell adhesion molecule binding proteins (p value 5.4 10) and a 4.2-fold enrichment for cytoskeletal binding proteins (supplementary table s3). web - based panther system biochemical pathway analysis of the top 24 differential splicing events within the go cellular component category, the genes listed in table 2 are significantly enriched for products found in the cell cortex (table 3 ; p value 2.6 10) and adherens junctions (p value 7.4 10). these enrichments are also noted in the full list of 101 genes (p value 2.2 10 and 9.1 10, respectively) (supplementary tables s2 and s3). finally, within the go biological process category, the gene list from table 2 was enriched for golgi organization (p value 1.7 10) and positive regulation of epithelial cell migration (p value 4.4 10) (table 3). neither of these enrichments was statistically significant in the full set of 101 genes (supplementary table s2). however, the larger gene set did have a notable enrichment for positive regulation of gtpase activity (p value 1.4 10) (supplementary table s3). several groups have confirmed a strong association between ctg tnr expansions in the tcf4 gene and fecd. we have also detected the colocalization of the splicing factor mbnl1 with transcribed cug sequences in rna foci in the nuclei of ce cells from patients with ctg tnr expansions in the tcf4 gene. these observations closely parallel those found in affected muscle tissue from patients with dm1. in dm1, more than a decade of research has established that sequestration of mbnl1 in rna foci of the effected muscle cells leads to widespread changes in rna splicing. in the present study, we identified a signature of missplicing events for fecd ce harboring ctg repeat expansion in tcf4. among the list of 101 missplicing events identified in both the pilot and the validation studies, 24 missplicing events (in 23 different genes) survived a higher level of screening by being present in at least 50% of comparisons in two independent data sets prepared with different library preparation techniques. our results confirm that there are widespread changes in pre - mrna splicing in the ce from fecd patients who have tnr expansions. the pathogenesis of dm1 is believed to be due to a ctg tnr expansion in the dystrophia myotonica protein kinase (dmpk) gene that causes rna toxicity due to the sequestration of mbnl1 in rna foci, leading to changes in rna splicing. it is notable that at least 16 of the 24 genes listed in table 2 are also differentially spliced in a mouse model of dm1. given the differences in species and tissue, this is a remarkable degree of concordance and is consistent with the possibility of overlapping pathogenic mechanisms between fecd and dm1. another two events (in sos1 and nfix) have also been noted in studies of patients with dm1. thus, at least 18 of 24 (75%) of the top splicing changes noted in fecd have also been linked to those in dm1, emphasizing the similarities between these two ctg tnr expansion diseases and suggesting a common pathogenesis, albeit in different tissues. within the validation set of samples discussed here, differential splicing of the transcripts of mbnl1, mbnl2, numa1, and ppfibp1 was detected in every fecd sample compared to controls, and differential splicing events were also noted in 43 of 44 comparisons for syne1 and add3. the inclusion of mbnl1 and mbnl2 in this list is expected, given their affinity for cug - rich sequences, which are abundant in the transcripts from the expanded repeats and their known roles in mrna splicing. it is interesting that the other four genes are also related to cellular events that have been linked to fecd. both syne1 and numa1 produce nuclear proteins implicated in apoptosis ; ppfibp1 is thought to regulate the disassembly of focal adhesions, and adducins (including the add3 gene product) are important in the stabilization of endothelial junctions. nesprin-1 (the product of the syne1 gene) has also been implicated in the regulation of cell adhesions. overall, the finding that more than 60% (14 of 23) of the most robust differential splicing events occur in genes coding for proteins that are involved in cytoskeletal protein binding or cell adhesion is in agreement with previous proteomic studies of fecd. quantitative proteomic analysis of ce / descemet 's membrane from fecd patients led poulsen. to conclude that proteins associated with cell anchoring and extracellular matrix organization were altered in fecd. our results suggest that some of the proteins that regulate the extracellular matrix and cytoskeleton in the ce might be qualitatively different as well, by virtue of widespread differential splicing events. the possible contribution of these changes to the pathogenesis of fecd will require further work, but the promising results in treating fecd with rho kinase (rock) inhibitors, which target rocks and influence cellular events involved with the cytoskeleton, cell adhesion and proliferation, suggests possible avenues for future experiments. in that regard, it is notable that, within the larger set of differential splicing events presented in supplementary tables s2 and s3, the focus on cell adhesion and cytoskeletal protein binding is extended and over a 7-fold enrichment for proteins that bind to gtpases emerges. the change in the splicing pattern of vegfa in patients with a tnr expansion is also of interest. previous work comparing the effect of vegf165 versus that of vegf121 on the barrier function of retinal vascular endothelial cells in culture suggests that vegf165 is more disruptive to barrier function than vegf121 through an effect on the tight junction protein claudin-1, which is expressed in ce. the tnr - associated increase in vegf165 in the ce could therefore impair the barrier function of the ce, which has been shown to be an early defect leading to fecd. the true functional significance of the novel splice form of fgfr2 that we have characterized is currently unknown. the consequence of the differential splicing is the exclusion of 17 amino acids in the extracellular third immunoglobulin (ig)-like domain. the first 3 of the 17 amino acids that are lost in this isoform (g345, n346, and s347) have been shown to interact with fgf2. it is known that other alternative splicing events in this ig - like domain do affect ligand specificity. thus, it is reasonable to hypothesize that the function of the receptor could be changed by this splicing event. the additional significance of this fgfr2 event is that it emphasizes the fact that the list of differential splicing events identified by miso and presented here is not exhaustive. the software for identifying differential splicing events is not perfect, and other biologically significant splicing alterations in fecd likely exist. we recognize that the studies presented here are based on a limited sample size (total of 15 fecd rna samples from patients with tnr expansions and 7 independent controls) and that the rna expression of the control samples may also be influenced by their diverse underlying diseases. the identification of splicing changes within mbnl1, mbnl2, numa1, and ppfibp1, which were identified in all 44 comparisons between fecd with expansion and control samples plus the 12 comparisons performed in the pilot group, minimizes this concern. however, it will be important to experimentally validate the effect of these splicing changes on the structure and function of individual proteins before the true consequences of these splicing changes for fecd can be known. although the presence of widespread splicing abnormalities do not confer proof that missplicing is the primary or sole mechanism of disease in fecd, the parallels with well - established pathogenesis of dm1 suggest that splicing changes secondary to sequestration of mbnl1 and mbnl2 are likely to be important in fecd as well. shared missplicing events in dm1 and fecd should bring into question the possibility of shared phenotypic features. a separate study of 52 patients with myotonic dystrophy (unspecified whether type 1 or 2) found that corneal thickness was greater than normal in dm, but no other endothelial abnormalities were noted. garcia filho. were unable to confirm a difference in corneal thickness in 12 dm1 subjects, but corneal endothelial parameters were not measured. although it has not been systematically studied, the presence of neuromuscular disease in patients with fecd has not been reported, and this holds true in our own clinical experience. while larger sampling with thorough methodology is needed to confirm an association such as that described by gattey., one must remember that the repeat expansion diseases described to date are tissue - specific, with distinct clinical phenotypes despite similar genetic bases. for example, both dm1 and spinocerebellar ataxia type 8 occur as a result of ctg expansion in the noncoding portion of their respective genes, yet the diseases are clinically distinct and involve different parts of the nervous system. genes, including those harboring repeat expansions, exhibit tissue - specific differential expression. additionally, mosaicism is common in repeat - associated diseases, with much longer repeat lengths present in certain tissues, such as the nervous system. genes with expansion may also use different promoters in different tissues, resulting in varied expression of the repeat sequence. the tcf4 gene has 48 different isoforms produced from 9 different promoters, with only some of the variants having the repeat expansion sequence. nevertheless, there are clearly many variables involved in determining the tissue specific pathogenicity of repeat expansion sequences, so shared clinical features between fecd and other repeat expansion diseases is not necessarily expected. the linkage of the differential splicing changes reported here to tnr expansions is emphasized by the absence of mis - splicing in this gene set in the fecd sample from a patient that lacked a tnr expansion. because we do not yet have splicing data for a meaningful number of fecd patients that lack repeat expansions, these findings must be viewed cautiously. still, these results do emphasize the reality that there are divergent genetic variants that lead to fecd, and no unifying pathogenic mechanism has been identified. nevertheless, the current mechanism involving missplicing of the candidate genes seems to hold true for fecd patients with tnr expansions. therefore changes in gene function through alternate splicing induced by tnr expansion can be a valid pathogenic mechanism in most fecd patients. furthermore, the overrepresentation of cytoskeletal and cell adhesion molecule - binding proteins in the differentially spliced group is further proof that rna splicing changes could contribute to the pathogenesis of fecd in the subset of patients with tnr expansions. | purposeto identify rna missplicing events in human corneal endothelial tissue isolated from fuchs ' endothelial corneal dystrophy (fecd).methodstotal rna was isolated and sequenced from corneal endothelial tissue obtained during keratoplasty from 12 patients with fecd and 4 patients undergoing keratoplasty or enucleation for other indications. the length of the trinucleotide repeat (tnr) ctg in the transcription factor 4 (tcf4) gene was determined using leukocyte - derived dna analyzed by a combination of southern blotting and genescan analysis. commercial statistical software was used to quantify expression of alternatively spliced genes. validation of selected alternative splicing events was performed by using rt - pcr. gene sets identified were analyzed for overrepresentation using web - based analysis system.resultscorneal endothelial tissue from fecd patients containing a ctg tnr expansion sequence in the tcf4 gene revealed widespread changes in mrna splicing, including a novel splicing event involving fgfr2. differential splicing of numa1, ppfibp1, mbnl1, and mbnl2 transcripts were identified in all fecd samples containing a tnr expansion. the differentially spliced genes were enriched for products that localize to the cell cortex and bind cytoskeletal and cell adhesion proteins.conclusionscorneal endothelium from fecd patients harbors a unique signature of mis - splicing events due to ctg tnr expansion in the tcf4 gene, consistent with the hypothesis that rna toxicity contributes to the pathogenesis of fecd. changes to the endothelial barrier function, a known event in the development of fecd, was identified as a key biological process influenced by the missplicing events. |
cysteinyl leukotrienes (cyslts), specifically lts c4, d4, and e4, are generated predominantly by cells of the innate immune system following exposure to allergens, proinflammatory cytokines, and other types of receptor - dependent stimuli. the resultant mobilization of ca from intracellular and extracellular reservoirs leads to activation of cytosolic phospholipase a2 (cpla2), as well as other types of pla2 enzymes, which cleave arachidonic acid from membrane phospholipids, which is a prerequisite for generation of cyslts [13 ]. acting in concert with perinuclear membrane 5-lipoxygenase- (5-lo-) activating protein (flap), arachidonate is oxygenated by 5-lo to lta4, which undergoes sequential conversion to ltc4, ltd4, and lte4 mediated by the enzymes ltc4 synthase, -glutamyl leukotrienase, and ltd4 dipeptidase, respectively [13 ]. these cyslts are then available to interact with specific cyslt receptors (cysltrs), namely, cysltr1 and cysltr2, expressed on the outer membrane of immune / inflammatory cells and structural cells. the former is the more widely distributed of the two types of receptor, being expressed on a range of cells of the innate immune system including basophils, mast cells, dendritic cells, eosinophils, and monocytes / macrophages, as well as b cells and cd4 t cells, and to a lesser extent on neutrophils and cd8 cells [13 ]. cysltr1 is also expressed on various types of structural cell, including airway smooth muscle, epithelial, and endothelial cells, as well as fibroblasts [13 ]. cysltr2, as well as other selective and more promiscuous types of cysltr, have a more limited cellular distribution, and although discrete functions of these are emerging, these will not be addressed in the current review which is focused on cysltr1 antagonists. interaction of cyslts with cysltr1 expressed on immune / inflammatory cells, airway smooth muscle, and other types of structural cell is intimately involved in many aspects of the immunopathogenesis of bronchial asthma, including chronic eosinophilic airway inflammation, bronchoconstriction, bronchial hyperresponsiveness, mucus hypersecretion, and airway remodeling. recognition of the cyslt / cysltr1 axis in the immunopathogenesis of bronchial asthma, as well as allergic rhinitis, provided the impetus for development of selective antagonists of cysltr1. pranlukast was introduced for clinical application in japan in 1995 and is currently marketed in this and several other asian countries. two others, montelukast and zafirlukast, were subsequently developed, receiving fda approval in 1998 and 1999, respectively. montelukast, probably due to its once daily dosing schedule and safety and efficacy profiles is the most widely prescribed cysltr1 antagonist in usa and europe. these agents have found niche applications in the treatment of allergic rhinitis, exercise- and aspirin - induced asthma, and as add - on therapy in patients with asthma poorly controlled by inhaled corticosteroid (ics) monotherapy or ics in combination with long - acting 2-agonists [4, 5 ]. topics to be covered in the following sections of this review include : (i) the cysltr - dependent proinflammatory interactions of cyslts with cells of the innate immune system, particularly neutrophils ; (ii) cysltr1-independent anti - inflammatory actions of the cysltr1 antagonists which target neutrophils and monocytes / macrophages in particular ; (iii) a comparison of the neutrophil - targeted, cysltr1-independent, suppressive effects of montelukast, pranlukast, and zafirlukast ; and (iv) current and potential applications of cysltr1 antagonists. the interaction of cyslts with their type 1 counter - receptors on cells of the innate immune system results in the release of a series of inflammatory mediators which, in addition to exacerbating bronchial hyperresponsiveness, mucus hypersecretion, and airway remodeling, also drive th2-cell - mediated eosinophilic airway inflammation. cells of the innate immune system which undergo activation on exposure to cyslts include mast cells / basophils, monocytes / macrophages, and myeloid dendritic cells, all of which also produce cyslts. this is surprising since neutrophils, as described in later sections of this review, are extremely sensitive to the suppressive effects of cysltr1 antagonists. the proinflammatory interactions of cyslts with mast cells [68 ], monocytes / macrophages [916 ], eosinophils [1720 ], dendritic cells [14, 21, 22 ], and neutrophils [2325 ], all of which are antagonized by montelukast and pranlukast or zafirlukast, are summarized in table 1. although neutrophils do not produce cyslts they do, however, express cysltr1, albeit at lower levels than the aforementioned cell types. exposure of human neutrophils to ltc4 and ltd4 has been reported to result in modest activation of ca mobilization and production of nitric oxide in comparison with ltb4 and other potent neutrophil chemoattractants [23, 24 ]. on the other hand adhesion to vascular endothelium, release of granule proteases, and nadph oxidase - mediated generation of superoxide anion are all unaffected following exposure of neutrophils to ltc4 and ltd4 [2325 ]. of greater potential significance, however, is the priming interaction of cyslts with human neutrophils, which sensitizes these cells for increased production of ros and release of mmp-8 following exposure of the cells to the chemoattractant, n - formyl - l - methionyl - l - leucyl - l - phenylalanine (fmlp). both the direct activating and sensitizing interactions of cyslts with human neutrophils are attenuated by either an experimental cysltr1 antagonist (skf 104353) [23, 24 ] or montelukast. in addition to anti - inflammatory activity achieved via blockade of cysltr1, montelukast, pranlukast, and zafirlukast have also been reported to possess anti - inflammatory properties, primarily targeting neutrophils and monocytes / macrophages, which are independent of cysltr1 antagonism. in this setting, the anti - inflammatory effects of these agents are achieved at concentrations somewhat higher than those required to achieve maximal cysltr1 blockade, but which are nonetheless close to the peak serum concentrations attained during chemotherapy with these agents. in the case of montelukast, this agent at a concentration of 0.1 m effectively suppresses ca mobilization following exposure of neutrophils to ltd4, while concentrations of 0.25 m are required to exert the cysltr1-independent effects described below. peak serum concentrations of 0.51 m are attained following oral administration of montelukast in the therapeutic setting [27, 28 ]. several experimental strategies have been used to ensure veracity of interpretation of the cysltr1-independent anti - inflammatory activities of the cysltr1 antagonists described below. these include (i) addition of inhibitors of the lt - generating enzyme, 5-lipoxygenase (5-lo), in the various assay systems to eliminate the potentially complicating effects of generation of cyslts by target cells and/or contaminating cells in the cell suspensions and (ii) inactivation of expression of cysltr1 on target cells using gene knockout strategies. several mechanisms underpinning the cysltr1-independent anti - inflammatory activities of cysltr1 antagonists have been described in detail elsewhere and are updated in the current review together with inclusion of several more recently described mechanisms. these are (i) inhibition of 5-lo, resulting in attenuation of production not only of cyslts but also of ltb4 [26, 30, 31 ] ; (ii) nonspecific inhibition of cyclic nucleotide phosphodiesterases (pdes) [26, 32 ], resulting in increased levels of 3,5-cyclic adenosine monophosphate (camp), a major regulator of the proinflammatory activities of cells of the innate immune system ; (iii) inhibition of the activity of the transcription factor, nfb [29, 3436 ] ; (iv) inhibition of prostaglandin e synthase ; (v) inhibition of eosinophil adhesion and migration [38, 39 ] ; and (vi) antagonism of purinergic p2y receptors. the inhibitory effects of montelukast and zafirlukast on the production of lts by both neutrophils and monocytes / macrophages are well documented [26, 30, 31 ] and are achieved at concentrations close to the peak serum concentrations of montelukast. notwithstanding attenuation of production of cyslts, inhibition of generation of the potent neutrophil chemoattractant, ltb4, by these agents represents a potential strategy to control hyperreactivity of the corticosteroid - resistant neutrophil. although montelukast was found to have direct inhibitory effects on 5-lo, this was only evident at very high concentrations of this agent, well above peak serum levels, suggesting the existence of an alternative mechanism of inhibition as described below. in addition to inhibition of 5-lo, montelukast at concentrations of 0.5 m has also been reported to inhibit the production of ros and release of elastase by chemoattractant - activated neutrophils, as well as expression of the 2-integrin, cr3 [26, 40 ]. inhibition of these neutrophil ca - dependent activities was associated with increased clearance of cytosolic ca in the setting of increased concentrations of intracellular camp [26, 40 ]. accelerated clearance of cytosolic ca and downregulation of neutrophil proinflammatory activity were attributed to activation of camp - dependent protein kinase (pka), which, in turn, promotes restoration of ca homeostasis by several mechanisms, including increased efficiency of ca sequestration / resequestration into stores. in addition, pka has also been reported to inhibit the activation of 5-lo. the potentiating effects of montelukast on camp, restoration of ca homeostasis, and attenuation of neutrophil proinflammatory activity were found to be closely correlated with direct, nonspecific, inhibitory effects of montelukast on cyclic nucleotide pdes. these effects of montelukast on cyclic nucleotide pdes have recently been confirmed by others using a model of salbutamol - mediated desensitization of 2-adrenoreceptors in airway smooth muscle cells, as well as in an isolated pde preparation. pranlukast and montelukast have been reported to inhibit the activation of the transcription factor, nfb, in a variety of cell types including monocytes / macrophages, t cells, epithelial cells, and endothelial cells (reviewed in [29, 34 ]). however, the mechanism underpinning the inhibitory effects of the cysltr1 antagonists on the activity of the transcription factor remain uncertain. while interference with nuclear translocation has been described, others have reported that the inhibitory effects of montelukast on nfb activity in monocytes / macrophages are not achieved via inhibition of dna binding. in this latter setting, treatment of the cells with montelukast was associated with significant inhibition of histone acetyltransferase (hat) activity, consistent with impaired activation of the transcriptional coactivator proteins which facilitate histone acetylation and unwinding of chromatin, events which precede and are a prerequisite for gene transcription. interestingly, pka has also been reported to negatively regulate nfb - activated gene transcription in monocytes / macrophages and endothelial cells without affecting interaction of the transcription factor with dna, consistent with the involvement of camp in montelukast - mediated interference with nfb. montelukast, pranlukast, and zafirlukast, at ic50 concentrations between 2 and 4 m, have been reported to inhibit the synthesis of prostaglandin (pg) e2 by isolated, lipopolysaccharide - activated human leukocytes, as well as by various cytokine - exposed cancer cell lines in vitro, apparently by direct inhibition of microsomal pge synthase-1. aside from cysltr1-independent anti - inflammatory effects, these observations may also be of significance in relation to the antitumor activities of cysltr1 antagonists. they should, however, be viewed in the context of the study by woszczek. who failed to detect inhibitory effects of either montelukast or zafirlukast on the production of pge2 by stimulated human monocytes / macrophages in vitro. as mentioned in a previous review, montelukast, at therapeutically relevant concentrations and above, has been reported to interfere with (i) the 41 (1-integrin)-mediated binding of eosinophils to vcam-1 and (ii) migration activated by the chemoattractant, 5-oxo-6,8,11,14-eicosatetraenoic acid, which was associated with impaired expression of the urokinase plasminogen receptor and release of mmp-9. this aspect of the cysltr1-independent anti - inflammatory activity of cysltr1 antagonists has recently been reviewed elsewhere. suffice it to say that montelukast, pranlukast, and zafirlukast, at micromolar concentrations, have been reported to antagonize the interactions of nucleotides with their p2y counter - receptors on human monocytes / macrophages, resulting in attenuation of synthesis of il-8 [29, 31 ]. however, given the relatively high micromolar concentrations of the cysltr1 antagonists at which these effects are achieved, their therapeutic significance remains uncertain. more recently pranlukast, at supratherapeutic concentrations of up to 50 m, was found to increase the activity of amp - activated protein kinase in a canine kidney cell line (mdck cells) by a putative cysltr1-independent mechanism involving activation of calcium / calmodulin - dependent protein kinase kinase beta. the effects of montelukast and zafirlukast were complicated by cytotoxicity at the high concentrations used. notwithstanding the high concentration of pranlukast required to achieve these effects, this mechanism, if operative in cells of the innate immune system, represents an additional mechanism of cysltr - independent anti - inflammatory activity. this is because amp - activated protein kinase suppresses the activity of nfb in human umbilical vein endothelial cells. these cysltr1-independent anti - inflammatory activities of montelukast, pranlukast, and zafirlukast are summarized in table 2 and figure 1. although the camp - mediated suppressive effects of montelukast have been documented previously [26, 29, 40 ], relatively little is known about the anti - inflammatory interactions of pranlukast and zafirlukast with these cells. this issue has been addressed in the current section of this review, specifically a comparison of the effects of the 3 cysltr1 antagonists on the production of ros and ltb4 by chemoattractant - activated human neutrophils in vitro, as well as the release of elastase from these cells in the context of nonspecific pde inhibitory activity. neutrophils with their arsenal of indiscriminate reactive oxygen species (ros) and proteases pose a potential threat to bystander host cells and tissues in the vicinity of inflammatory reactions. few currently available therapeutic agents, including corticosteroids, effectively control the harmful proinflammatory activities of neutrophils [45, 46 ]. we have previously found that montelukast, primarily a cysteinyl leukotriene (cyslt1) receptor antagonist, exhibited secondary, neutrophil - directed anti - inflammatory properties, which appeared to be camp - mediated. we have recently compared the effects of montelukast, pranlukast, and zafirlukast at therapeutically relevant concentrations on several ca - dependent, proinflammatory activities of isolated human neutrophils. montelukast was provided by merck research laboratories (rahway, nj, usa), zafirlukast by astrazeneca (johannesburg, south africa), and pranlukast was purchased from the cayman chemical company (ann arbor, mi, usa). all 3 agents were dissolved to a stock concentration of 10 mm in dimethylsulfoxide (dmso) and used at final concentrations of 0.252 m. the final concentration of dmso in each assay was 0.1% and appropriate solvent controls were included with each experimental system. unless indicated, all other chemicals and reagents were purchased from sigma - aldrich (st louis, mo, usa). the study was approved by the faculty of health sciences research ethics committee of the university of pretoria, pretoria, south africa, and prior informed consent was obtained from all blood donors. neutrophils were isolated from heparinized venous blood (5 units of preservative - free heparin per ml of blood) from healthy adult volunteers as described previously and resuspended to 1 10 cells per ml in phosphate - buffered saline (0.15 m, ph 7.4) and held on ice until used. for the assays described below, the cells were suspended in hanks ' balanced salt solution (indicator - free ; ph 7.4 ; highveld biological, johannesburg, south africa). the results of each series of experiments are presented as the mean values the standard errors of the means (sems), where n equals the number of different donors. levels of statistical significance were determined by comparing the absolute values for each drug - treated system with the corresponding values for the relevant drug - free control systems for each assay using the wilcoxon matched pairs test. this was measured using a lucigenin- (bis - n - methylacridinium nitrate-) enhanced chemiluminescence (lecl) procedure as previously described. following pretreatment of the neutrophils with the 3 agents, the cells were activated with the chemoattractant, n - formyl - methionyl - leucyl - phenylalanine (fmlp, 1 m), and lecl responses recorded as described. the results, which are shown in figure 2, indicate that all 3 agents at concentrations of 0.252 m caused essentially comparable, dose - related inhibition of the generation of superoxide production which achieved statistical significance at all the concentrations tested. neutrophil degranulation was measured according to the extent of release of the primary granule enzyme, elastase, as previously described. supernatants of cells, pretreated with the 3 test agents and activated with fmlp / cytochalasin b (f / cb, 1 m/1 m), were assayed for elastase using a standard colorimetric method. montelukast, pranlukast, and zafirlukast at concentrations of 0.252 m caused essentially comparable, dose - related inhibition of the generation of elastase release which achieved statistical significance at all the concentrations tested. a competitive binding immunoassay procedure (correlate - eia ;, ann arbor, mi, usa) was used to measure ltb4 in the supernatants of neutrophils activated with the chemoattractant, platelet - activating factor (paf, 200 nm), in the absence and presence of the leukotriene receptor antagonists (0.5 and 1 m). all 3 test agents caused statistically significant, dose - related inhibition of ltb4 production by paf - activated neutrophils with zafirlukast being most potent. the pde inhibitory activity of montelukast, pranlukast, and zafirlukast was assessed using a scintillation proximity assay (spa, amersham biosciences, uk) as described previously. reaction mixtures contained neutrophil cytosol, as a source of pde, [h]camp or [h]cgmp, in the absence and presence of the cysltr1 antagonists (0.520 m). as shown in figure 5, the cysltr1 antagonists at concentrations of 0.520 m caused dose - related inhibition of both camp- and cgmp - pde activity which in all cases achieved statistical significance at concentrations of 2 m. these findings demonstrate that all 3 cysltr1 antagonists possess nonspecific pde inhibitory activity. to determine the effects of pranlukast and zafirlukast (2 m) on neutrophil viability, intracellular atp concentrations were measured in cell lysates (1 10 cells / ml) following exposure of the cells to the drugs for 10 min at 37c, using a luciferin / luciferase chemiluminescence procedure. as reported previously for montelukast, treatment of neutrophils with these agents did not affect neutrophil atp levels ; the values for the control and pranlukast- and zafirlukast - treated cells were 6.4 0.34, 6.84 0.50, and 6.72 0.49 pmols atp/10 cells, respectively (n = 2, with seven replicates for each system in each experiment). the results of the aforementioned experiments demonstrate that montelukast, pranlukast, and zafirlukast, at concentrations within the therapeutic range and above, caused significant, dose - related inhibition of superoxide generation, as well as production of ltb4 and release of elastase, by activated neutrophils. the effects of the 3 agents were mostly comparable although zafirlukast was more potent than the other agents with regard to its inhibitory effect on ltb4 production. the observed effects were not due to cytotoxicity as the drugs did not affect levels of cellular atp. although not shown, the inhibitory effects of all 3 test agents on the generation of ros by chemoattractant - activated neutrophils were unaffected by the inclusion of the 5-lo inhibitor, mk886 (0.5 m), in the assay system, consistent with lack of involvement of cysltr1 antagonism. from a mechanistic perspective, all 3 cysltr1 antagonists, at concentrations virtually superimposable on those which suppressed the production of inflammatory mediators by neutrophils, although the existence of other mechanisms of cysltr1-independent anti - inflammatory activity can not be excluded, nonspecific pde inhibitory activity is likely to underpin the anti - inflammatory effects of the cysltr1 antagonists. in this setting, elevations in intracellular camp promote downregulation of neutrophil proinflammatory activity via accelerated clearance of ca from the cytosol of activated cells [26, 40 ]. in support of this proposed mechanism, we have also observed that all 3 cysltr1 antagonists, at concentrations which inhibit pde activity and production / release of inflammatory mediators, also promote accelerated clearance of ca from the cytosol of activated neutrophils (not shown). although the 3 test agents have been found to effectively suppress the proinflammatory activities of neutrophils in vitro by a cysltr1-independent mechanism, the clinical significance, as well as the aspects of molecular structure which confer nonspecific pde inhibitory activity on these agents, remains to be established. the final section of this review is focused on the current clinical applications of cysltr1 antagonists, as well as potential future clinical indications. cysltr1 antagonists have a significant role to play in airway disorders, in particular allergic rhinitis (ar) and/or asthma [48, 49 ]. studies have also suggested that they may have potential benefit in other disorders that are often associated with asthma, as well as in a number of conditions that are not linked to asthma. this section will review the role of cysltr1 antagonists in allergic rhinitis (ar) and asthma, including pediatric, adult, and elderly patients, as well as the various subsets of asthmatic patients, such as those with ar, those with aspirin - sensitive asthma and those with exercise - induced asthma. most well studied has been the role of montelukast in the management of these various conditions, which will therefore be the focus of this section. this is followed by a brief consideration of potential, albeit unproven, clinical applications of cysltr1 antagonists. as mentioned earlier, cysltr1 antagonists, particularly montelukast, have been registered in a number of countries for the treatment of ar and are considered to be a suitable alternative to other available therapies. the conclusions of a number of studies, as well as an evidence based review, is that montelukast is superior to placebo in alleviating symptoms of both seasonal and perennial ar, that as monotherapy it is equivalent to the anti - histamine, loratadine (second generation h1 receptor antagonist), but is not as efficacious as intranasal fluticasone propionate and that when combined with loratadine or cetirizine has superior efficacy to each of these agents alone, producing results similar to those of intranasal corticosteroids [5052 ]. in one study comparing an intranasal corticosteroid, a cysltr1 antagonist and a topical antihistamine, the authors concluded that montelukast, because of its systemic effects, is more efficacious at relieving symptoms beyond the nasal cavity. in one study of montelukast, given either alone or combined with desloratadine or levocetirizine in patients with persistent ar, a significant improvement of nasal symptoms was documented in the first 24 hours, which gradually increased up to 6 weeks. another study of patients with seasonal ar documented montelukast 5 mg or 10 mg once daily to be as safe and effective as pranlukast (450 mg / day). the cyslts have, at least in some patients, been shown to play a leading role in the various pathological airway manifestations of asthma that lead to symptoms, including the occurrence of bronchoconstriction, formation of edema, and hypersecretion of mucus. it is therefore not surprising that the cysltr1 antagonists have enjoyed a well - established role in the treatment of patients with asthma for a considerable number of years, with efficacy and safety confirmed in a myriad of studies [3, 5763 ]. the clinical benefits have been documented in various studies and reviews for montelukast [4, 6466 ], zafirlukast [6771 ], and pranlukast [7278 ]. one area of contention is the exact role of cysltr1 antagonists in the treatment algorithm for asthma, whether this should be as a monotherapy alternative to inhaled corticosteroids (ics) or as an add - on therapy to corticosteroids instead of long - acting beta - agonists (laba) and the relative efficacy of the cysltr1 antagonists compared to these alternative treatment options [50, 79 ]. study in asthmatic patients, involving two parallel multicenter pragmatic trials, suggested that cysltr1 antagonists may be equivalent to ics as first - line monotherapy and equivalent to laba as add - on therapy in patients with asthma not controlled on ics alone, although the authors did recommend caution in the interpretation of the results because of the nature of the studies. interestingly, adherence to cysltr1 antagonist therapy was better than the other agents used in those studies. nevertheless, extensive review of the various studies has suggested, firstly, that ics appear to have superior efficacy to antileukotrienes in many adults and children with asthma, and particularly those with moderate airway obstruction, such that guideline recommendations of ics as preferred monotherapy appears appropriate [81, 82 ]. secondly, review of data for add - on therapy for patients with asthma not adequately controlled on ics alone suggests that while cysltr1 antagonists do appear to have benefit, the efficacy of the addition of laba may be greater [8385 ]. however, it does appear that cysltr1 antagonists may have a better long - term safety than labas. some experts have suggested that the choice of add - on therapy (either labas or cysltr1 antagonists) should also be tailored to individual asthma patients (see also asthma phenotypes described below). all of the licensed cysltr1 antagonists are available in pediatric doses, but montelukast (registered in many areas from even 6 months) has been the most investigated. a myriad of studies and reviews attest to the potential benefits and safety of montelukast in pediatric asthma, although it is recognized that there are individual variations in response among the patients [8796 ]. there is some debate as to the exact place of montelukast and other cysltr1 antagonists in the management of pediatric patients, but it has been proposed that they may be used as an alternative to ics as monotherapy in intermittent or mild persistent asthma, particularly in those who can not or will not use ics, or as add - on therapy for patients not controlled on ics alone or as add - on therapy to reduce ics doses in moderate or severe asthma, and in specific patient phenotypes (such as children aged 25 years to prevent frequent exacerbations and in those with concomitant ar) or in exercise - induced bronchospasm, or viral - induced wheeze [90, 92, 93, 95 ]. although some studies have suggested that montelukast is an effective monotherapy controller for mild asthma in children, a recent systematic review comparing montelukast with ics reported that the majority of studies indicated that ics are as effective as or more effective than montelukast, and the authors concluded that ics should remain the first - line treatment option for children with mild - moderate asthma [91, 96 ]. however, what studies there are have suggested that these agents, particularly montelukast, are effective even in the elderly with severe asthma and appear overall to have equivalent benefit as add - on therapy to regular maintenance treatment as compared to younger patients [97, 98 ]. one problem with asthma treatment in the elderly is low adherence to therapy, and the easier route of administration of montelukast (oral agent versus inhaler) could be associated with improvement in overall treatment. while many patients with asthma have allergic rhinitis, it is also recognized that patients with ar are more likely in the future to develop asthma, so that the two conditions frequently coexist. it has been increasingly recognized that these two conditions appear, therefore, to be linked by being interacting manifestations of a common pathological mechanism ; this association is often being described as both montelukast and zafirlukast have been shown to be effective for the treatment of these two conditions when they occur either alone, as described above, or concomitantly [48, 52, 99102 ]. there has been interest in the use of both oral and intravenous cysltr1 antagonists in the management of patients with acute asthma as an adjunct to standard care. in the case of intravenous montelukast, randomized studies in adults have shown greater efficacy than placebo, with a significant increase in forced expiratory volume in one second (fev1) [103105 ] ; however, a similar study in children was unable to show benefit on fev1, asthma symptoms, or the hospital course. similar randomized, double blind, placebo - controlled studies of oral montelukast in adult patients with acute asthma exacerbations, treated with standard of care, have documented only a higher peak expiratory flow (pef) the morning after admission or no benefit. in children (515 years of age) the addition of a single dose of oral montelukast to standard treatment in acute moderate to severe asthma showed no additional clinical benefit. other investigators, using data from additional studies have questioned whether there may be a role for oral montelukast in asthma exacerbations [110, 111 ]. nevertheless, a systematic review of the available data concluded that there was no evidence to support the routine use of oral cysltr1 antagonists in acute asthma in either adults or children. a study was undertaken to test the hypothesis that administration of montelukast (10 mg / day) would increase asthma control over 6 months, compared with placebo, in asthmatics that smoked. the reason for performing such a study was due to the contention that smokers with asthma have a reduced response to corticosteroids. this was a parallel group study in which one additional arm was treated with fluticasone propionate (fp) (250 g). the main findings of the study were that montelukast therapy increased the mean percentage of asthma control days, as did fp, and while fp tended to have more benefit in patients with a pack - year smoking history 11 pack - years. others have also suggested a greater benefit of montelukast in smokers, but clearly more data is required. exercise - induced bronchospasm occurs commonly in asthmatic patients, both adult and children, sometimes as the only trigger of asthma and also occasionally in nonasthmatic patients. a number of pharmacological and nonpharmacological treatment approaches are recommended for the management of patients with eia, which also include the cysltr1 antagonists, especially montelukast or zafirlukast [5, 115124 ]. both montelukast and zafirlukast have been used either long term, particularly in asthmatic patients not controlled on baseline anti - asthma therapy, or even short term / acutely (e.g., single dose prior to exercise) and to provide useful protection against eia, although there is some debate as to whether these agents are equivalent to or more or less effective than labas [5, 115124 ]. intolerance to aspirin and other nonsteroidal anti - inflammatory agents (nsaids) may sometimes be a considerable clinical problem in patients with asthma, and following their discovery it became evident that the leukotrienes appeared to play an important role in these patients. the mechanism appears to be related to cyclooxygenase inhibition by aspirin / nsaids, possibly resulting in excessive production of cyslts. studies using cysltr1 antagonists and other leukotriene modifiers have suggested that these agents may be of benefit in patients with aspirin - intolerant asthma [125, 126 ]. one randomized, double blind, placebo controlled study in aspirin - intolerant asthmatics, of whom 90% were already on moderate - to - high doses of corticosteroids, demonstrated a considerable improvement in asthma in the montelukast treated arm, which was unrelated to baseline lte4 levels. it is also being increasingly recognized that cysltr1 antagonists may have benefit in diseases beyond allergic rhinitis and asthma, some of which are described later, although none of these agents is currently registered for use in these conditions. one disease entity that has been particularly well studied is chronic obstructive pulmonary disease (copd). there has been interest in whether leukotriene modifiers may have a role in the management of copd, although data have been relatively limited. however, studies with montelukast in both the short term and long term have suggested benefit in patients with copd. in the former study, which was a randomized, prospective, single - blind, controlled study in 117 patients with copd, randomized to ipratropium, formoterol and montelukast, or ipratropium and formoterol alone, showed benefits of montelukast, in addition to standard therapy, improved lung function testing, dyspnoea score, and quality of life. the long - term study in copd patients showed benefits of addition of montelukast to standard therapy including a significant improvement in symptoms, reduction in corticosteroid and bronchodilator therapy, and reduction in emergency room visits and hospitalizations or duration of hospitalizations for exacerbations, although there was no effect on lung function. a more recent study in elderly patients with copd in whom montelukast 10 mg / day was added documented a decrease in serum levels of ltb4 and interleukin-8 (il-8) as well as a decrease in the number of outpatient visits and the number and duration of hospitalizations. montelukast was also documented to attenuate hypertonic saline - induced airway responses in patients with copd. in a number of studies, zafirlukast has been shown to have beneficial effects on lung function in patients with copd, including those with severe airflow limitation, even in the short term, and therefore these agents have been labelled as having either bronchodilator or antibronchoconstrictor effects in copd patients [132, 133 ]. cyslts also contribute to the immunopathogenesis of numerous inflammatory disorders involving multiple organ systems. together with modest cysltr1-mediated suppressive effects on neutrophils, the cysltr1-independent anti - inflammatory activities of cysltr1 antagonists are of potential therapeutic value in controlling harmful neutrophilic inflammation in many disorders including acute respiratory distress syndrome (ards) and systemic sepsis [134, 135 ]. eosinophils and mast cells are also involved in the immunopathogenesis of eosinophilic gastroenteritis and systemic mastocytosis, respectively [136, 137 ], as are activated t cells in inflammatory bowel disease and atherosclerosis [137, 138 ]. disorders other than asthma and allergic rhinitis in which cysltr1 antagonists have been used as experimental therapy are listed in table 3 [133, 134, 136175 ]. the wide range of organ systems and pathological processes for which cysltr1 antagonists are potentially useful is likely a reflection of their diverse anti - inflammatory activities. however, further research is needed to fully elucidate the role of cysltr1 antagonists in managing these conditions. cyslts produced predominantly by cells of the innate immune system modulate host defences via their sensitizing and stimulatory effects on immune and inflammatory cells, as well as on various types of structural cells. however, if produced inappropriately and/or excessively, cyslts contribute to the immunopathogenesis of acute and chronic inflammatory conditions of both infective and noninfective origin. elucidation of the involvement of cyslts in the immunopathogenesis of allergic rhinitis and some subtypes of bronchial asthma led to the development of cysltr1 antagonists, which are used primarily in the therapy and prophylaxis of these conditions. the discovery that these agents also possess secondary, cysltr1-independent anti - inflammatory activities has evoked an awareness of the broader therapeutic utility of these agents, although specific clinical applications remain to be established. | cysteinyl leukotrienes (cyslts) are produced predominantly by cells of the innate immune system, especially basophils, eosinophils, mast cells, and monocytes / macrophages. notwithstanding potent bronchoconstrictor activity, cyslts are also proinflammatory consequent to their autocrine and paracrine interactions with g - protein - coupled receptors expressed not only on the aforementioned cell types, but also on th2 lymphocytes, as well as structural cells, and to a lesser extent neutrophils and cd8 + cells. recognition of the involvement of cyslts in the immunopathogenesis of various types of acute and chronic inflammatory disorders, especially bronchial asthma, prompted the development of selective cyslt receptor-1 (cysltr1) antagonists, specifically montelukast, pranlukast, and zafirlukast. more recently these agents have also been reported to possess secondary anti - inflammatory activities, distinct from cysltr1 antagonism, which appear to be particularly effective in targeting neutrophils and monocytes / macrophages. underlying mechanisms include interference with cyclic nucleotide phosphodiesterases, 5-lipoxygenase, and the proinflammatory transcription factor, nuclear factor kappa b. these and other secondary anti - inflammatory mechanisms of the commonly used cysltr1 antagonists are the major focus of the current review, which also includes a comparison of the anti - inflammatory effects of montelukast, pranlukast, and zafirlukast on human neutrophils in vitro, as well as an overview of both the current clinical applications of these agents and potential future applications based on preclinical and early clinical studies. |
solitary fibrous tumor (sft) is a rare tumor which was first described as originating from the pleura and occurring most commonly in the thoracic cavity3,9,12). however, it is now recognized that these rare tumors can occur throughout the body7,14). there have been only 8 case reports of extradural spinal sft, also only 8 case reports of head and neck sft involving bony structures4,5). although the majority of sft are benign, sometimes these tumors show aggressive clinical course including recurrence or multiple invasions, report on a malignant sft of the spine or skull is extremely rare5). we report on a first case of malignant sft of tandem lesions in the skull and spine with a rapid recurrence and metastasis. a 54-year - old female patient was referred to our spine center with a two - month history of lower back pain and radiating pain in both legs, which was persistent even at night. lumbo - sacral magnetic resonance imaging (mri) showed a heterogeneously enhanced 6.7 cm sized lesion involving the sacrum, sacroiliac joint, and both illium with extraosseous mass formation containing a necrotic portion (fig. 1a). we performed positron emission tomography / computed tomography (pet / ct) and bone scan to assess for metastatic lesion. pet / ct and bone scan revealed hot uptake in the sacro - pelvic area, t8, and occipital skull area. thoracic mri showed an epidural enhancing 1.7 cm sized lesion in the posterior element of t8 (fig. in addition, findings on brain imaging studies showed an enhancing mass measuring 3.8 cm with occipital bone destruction and mild brain compression (fig. pathology of the biopsy indicated a type undetermined malignant neoplasm, suspected as a malignant spindle cell tumor. on angiography, large feeding vessels were observed in sacral lesion, and tumor embolization using gelfoam was performed prior to perform an open surgery. partial removal of the tumor in sacroiliac area was done ; then, gross total removal of the tumor at t8 was subsequently performed in a single stage. the tumor was extremely hypervascular and was not well demarcated. for the remnant tumor of the sacroiliac area, postoperative stereotactic radiosurgery using novalis tx (brainlab, inc., ammerthalstrabe, germany) was administered at a dose of 4 fractionated 32 gy, which encompassed 100% of the tumor volume. after open surgery and radiosurgery, her lower back pain and radiating pain showed improvement. three weeks after first open surgery, gross total removal of the tumor in the occipital skull was performed after tumor embolization. tumors of the sacro - pelvic area, t8, and occipital area showed identical histologic features. the tumors consisted of fusiform or spindle cells and showed a hemangiopericytoma - like perivascular pattern or a so - called patternless pattern, with intervening irregular hyalinzed collagen bundles, typical for a solitary fibrous tumor. mitotic figures were frequently observed [up to 10/10 high - power fields (hpfs) ]. by immunohistochemistry, the tumor cells were positive for cd34, cd99, bcl-2 and ema (focal - like +). as a result, the tumors were diagnosed as malignant solitary fibrous tumor (fig. although there was a lack of clinical evidence about adjuvant chemotherapy or radiotherapy, adjuvant chemotherapy with adriamycin and cisplatin was administered. however, just 2 days after starting adjuvant chemotherapy, one month after the initial surgery, she complained of aggravated upper back pain and paraparesis. findings on follow - up thoracic mri showed a recurred expansive posterior epidural mass with cord compression at t8 (fig. follow - up whole spine mri and chest radiography revealed metastasis in multiple vertebrae and both lungs. although palliative cervical and thoracic spine radiotherapy (dose of 5 fractionated 15 gy) was performed for relieving intractable pain, her symptoms did not show improvement and the patient finally died due to poor general condition six months after first open surgery. classically, sft, also known as localized fibrous tumor, has been known as a rare spindle - cell neoplasm originating from the pleura. since the first case report in 1931, studies of sft from the pleura were prolific in the 1980s12,15). although sft occurs mainly in the pleura, it can be seen in various organs, and has recently been considered to be a mesenchymal neoplasm originating from ubiquitous dendritic interstitial cells2). according to previous studies, approximately 30% of sft arise in extrathoracic locations11). reported extrathoracic locations include the mediastinum, pericardium, peritoneum, retroperitoneal space, pelvis, adrenal gland, kidney, liver, periosteum, salivary gland, thyroid gland, lacrimal gland, breast, nasopharynx, orbit, urogenital system, skin, meninges, and spinal cord10). due to overlapping histologic features, differentiation of sft from other soft tissue tumors may be difficult. performance of immunohistochemical staining is necessary in order to rule out other differential diagnoses19). typical immunohistochemical features of sft are a positive result for cd34, bcl-2, and cd99, and a negative result for -sma, desmin, pan - cytokeratin, and s-100 protein11). however, these markers are frequently overexpressed in a range of other soft tissue tumors including hemangiopericytoma4). as a result, a differential diagnosis of hemangiopericytoma with sft is difficult, even though their clinical courses are obviously different16). therefore, 2002 world health organization criteria for soft - tissue tumors treats those two neoplastic entities as a single section, and many lesions that were called hemangiopericytomas prior to 1990 could now be called sft5,10). however, in general, hemangiopericytomas are more cellular and have higher ki-67 rated of 5 - 10%6). in the current case, most thoracic sfts are asymptomatic at presentation and are diagnosed as incidental finding on radiographs and ct images of the chest9). extrathoracic sfts, however, are usually symptomatic ; depending on location, the manifestations are a painless mass or local pressure effects. in addition, an association of approximately 5% of sfts with hypoglycemia due to secretion of insulin - like growth factors has been reported20). in the current case, initially, the patient complained lower back pain with radiating pain in both legs due to compression of nerve roots of s1 and s2. in imaging studies, including mri and ct, imaging features of sft are relatively nonspecific. however, in general, sfts have discrete margins, and the majority of sfts have shown a lobulated contour. sfts were typically well defined, tending to displace adjacent structures, and local invasion is not common. however, in our case, the tumor margin was not well defined, and local invasion was obvious. as in the current case, a useful distinguishing imaging feature of sfts is the presence of large collateral feeding vessels. however, the presence of these vessels does not appear to be related to the histologic subtype of the tumor20). on the other hand, the tumor occurred in multiple tandem regions, including the skull, thoracic spine, lumbo - sacral spine, and plevic bone. the current report is first case about the malignant sft of multiple tandem lesions. at present, due to the rarity of the disease, standard therapies for malignant sft have not been well established. surgical en bloc removal has been recommended as the treatment of choice for sft9). recurrence occurred commonly in cases involving incomplete excision, possibly caused by the level of difficulty in achievement complete resection. in these cases, the majority of sfts are benign, and the malignant form accounts for 9 - 22%6,11). based on previous case reports, malignant sft showed rapid local recurrence and distant metastasis6). some authors have suggested that the size of a sft is one of the best indicators of malignancy1,13,17). in addition, findings such as nuclear atypia, increased cellularity, necrosis, and greater than 4 mitoses/10 hpfs, are suggestive of the malignant potential of sfts18). otherwise, some studies have reported that the prognosis of an sft is most likely dependent upon complete resection rather than histologic findings8). hence, careful follow - up may be needed, even if the tumor is small and benign in appearance at the time of presentation5,8,11). the current patient showed malignant characteristics with respect to tumor size, multiple lesions, local invasion, impossibility of complete resection, and histopathologic findings. fortunately, at initial presentation, the current patient showed a significant response to open surgery and radiosurgery. however, despite multidisciplinary treatment including adjuvant chemotherapy and radiotherapy, the tumor showed rapid local recurrence and aggressive metastasis to the whole spine and lung. the authors report here the first case of patient with malignant sft of tandem lesions in the skull and spine with a rapid recurrence and metastasis. although malignant sft is extremely rare, it should be considered in the differential diagnosis of tumors in the spine and skull, and carful follow - up is needed. | a solitary fibrous tumor (sft) is a rare neoplasm originated from the pleura, but they can occur in a variety of extrathoracic regions. although many cases of primary sft have been reported, there are extremely rare repots to date of a malignant sft in the spine or skull. a 54-year - woman visited our hospital due to low back pain and both leg radiating pain. several imaging studies including magnetic resonance imaging and computed tomography revealed expansive enhanced lesions in the occipital bone, t8, s1 - 2, and ilium, with neural tissue compression. we performed surgical resection of the tumor in each site, and postoperative radiosurgery and chemotherapy were performed. however, after six months, tumors were recurred and metastasized in multiple regions including whole spine and lung. the authors report here the first case of patient with malignant sft of tandem lesions in the various bony structures, including skull, thoracic spine, and sacral spine, with a rapid recurrence and metastasis. although malignant sft is extremely rare, it should be considered in the differential diagnosis and carful follow - up is needed. |
alzheimer 's disease (ad) is the most common form of dementia involving slowly developing, ultimately fatal neurodegeneration with massive brain atrophy especially in the medial temporal lobe, including the hippocampus (hardy, 2006 ; haass and selkoe, 2007 ; wang., 2007). ad is pathologically characterized by the presence of cerebral senile plaques containing extracellular deposits of -amyloid peptide (a) from the amyloid precursor protein (app), the accumulation of intraneuronal neurofibrillary tangles (nfts) containing hyperphosphorylated tau protein, dysfunction of synapses, and loss of neurons (mattson, 2004 ; hardy, 2006). in the 1990s, studies indicated that the most significant correlation to the severity of the cognitive impairment in ad was the loss of synapses in the frontal cortex and limbic system. several years later, evidence supports the contention that neuronal cell death might occur later than the progression of neurodegeneration, and damage to the synapto - dendritic apparatus might be one of the earliest pathological alterations (scheff and price, 2003 ; scheff., 2006). this is accompanied by the abnormal accumulation of a intraneuronally and extracellularly (e.g., plaques) or in intracellular compartments (e.g., tangles). abnormal accumulation and misfolding (toxic conversion) of these synaptic and cytoskeletal proteins are being explored as key pathogenic events leading to neurodegeneration (billings., 2005 ; mckee., 2008 we (wang., 2010) and other group (demars., 2010) recently identified that neurogenesis is compromised prior to any overt signs of ad - like pathology in a triple - transgenic mouse model of the disease. we propose that the neuronal loss in brain affected by ad may be due not only to the high death rate of neurons in affected brain regions, but also due to the reduced rate of the generation of new neurons. the reduction of generation of new neurons results in the limiting to replace the old, damaged, and dying neurons. in addition, the lower amount of new cells will further worsen the local micro - environment and will increase the speed of losing neurons (wang., 2007, 2010). therefore, the decrease of generation of new neurons may be the major causal factor. most ad is sporadic and the causal factors have not been clearly identified. some complex interactions among different genetic variants and environmental factors are believed to modulate the risk for the vast majority of late - onset ad cases (mcdonald., 2010). for example, the individuals carrying the 4 allele (a point mutation generated amino acid substitution from cysteine to arginine at position 158) of apolipoprotein e (apoe) on chromosome 19 have an increased risk for developing sporadic ad. however, epidemiological studies indicate that the presence of the apoe 4 allele can not explain the overall heritability of ad, implying that a significant proportion of ad cases is attributable to additional genetic risk factors (bickeboller., 1997 ; laferla., recently identified polymorphism p86l in calcium homeostasis modulator 1, which increases a levels by interfering with calcium homeostasis modulator 1-mediated ca permeability, is an example (dreses - werringloer., 2008 ; marambaud., although a detailed investigation to study the contribution of apoe 4 allele and calhm1 p86l in a population who carrying both point mutations is still missing, combined evidence suggests that sustained disruption of intracellular ca signaling may play an early proximal and perhaps central role in ad pathogenesis (smith., 2005 ; gandy., 2006 ; tu., 2006 ; green and laferla, 2008). interestingly, accumulated data indicated that transient increase of intracellular calcium concentration ([ca]i) may facilitate the neurogenesis (dayanithi and tapia - arancibia, 1996 ; wang and brinton, 2008). numerous efforts have been made develop therapeutic strategies to delay or reverse the progression of neurodegenerative diseases, including ad. two recently published reviews have summarized the potential cellular targets for developing drugs to regulate the progression of neurodegenerative diseases (aguzzi and rajendran, 2009 ; rajendran., 2010). the current review specifically focuses on the potential targets involved in regulating the [ca]i and subsequently mediated neurogenesis in neurodegenerative condition. ca is a ubiquitous second messenger that has been implicated in the regulation of a variety of events in developing neurons, including proliferation, migration, differentiation, and circuit formation (gomez and spitzer, 2000 ; spitzer, 2008). cells commence to divide by crossing from g1 to s phase and initiating dna amplification, a transition that is often environmentally regulated and associated with [ca]i transient increases (spitzer., 1995 ; it have been reported that transient [ca]i increases within the neural progenitor cells (npc) is triggered by a neurosteroid, allopregnanolone, which is a gabaa receptor modulator, and is mediated by a voltage - gated calcium channel. in addition, contact - dependent signals and short - range diffusible factors such as neurotrophins may also influence [ca]i. many growth factors, including bfgf, act via tyrosine kinase receptors that in turn can lead to release of ca from intracellular stores (chao., 1992 ; reddy, 1994 ; berridge, 1995 ; gomez - lechon., 1996). transient increases in [ca]i have been associated with the onset of cytokinesis and with the activation of actomyosin filaments that serve to separate daughter cells at the end of telophase (ratan., 1988). the [ca]i increases observed in doublets could be associated with these cell cycle events (ratan., 1988). both ca influx and release of ca from intracellular stores contribute to the [ca]i fluctuation associated with granule cell migration (komuro and rakic, 1996) and dendritic spine growth cone formation (spitzer. all these data indicate that transient [ca]i increase enhances neurogenesis, from proliferation, migration and the growth of neurorites. in addition to the effects on proliferation, the ap-induced transient increase of [ca]i also contributes to the release of oxytocin from supraoptic nucleus of those very young rats, but not old rats (viero., 2006). further study confirmed that neuroactive steroids on [ca]i transients is mediated by gabaa receptor activation and suggested an involvement of voltage - activated ca channels in cultured dorsal root ganglia neurons at embryonic stage e13 (viero., 2006). in contrast to the transient calcium increases which lead to the cell proliferation and neuropeptide release, sustained increases of [ca]i is a basic molecular mechanism for the increased sensitivity of cell response to toxicity and may eventually lead to cell death. for example, exposure of cultured pc12 cells to staurosporine, a broad spectrum protein kinase inhibitor, has been used to induce cell death in a wide range of cell types, resulted in prolonged (16 h) elevation of [ca]i and cell apopotosis (kruman., 1998 ; seo and seo, 2009). in many cell types, alteration of [ca]i plays a pivotal role in initiating apoptosis. analysis of brain tissue from ad patient showed that a sustained [ca]i increase is associated with the neurofibrillary tangle - bearing neurons (murray., 1992). in addition, a impaired the proliferation and neuronal differentiation of cultured human and rodent npc, and promoted apoptosis of neuron - restricted npc by a mechanism involving dysregulation of cellular calcium homeostasis and the activation of calpains and caspases (haughey., 2002 ; nimmrich., 2008). numerous findings have also suggested that perturbation of [ca]i signaling contributes to many age related neurodegenerative disorders, including : parkinson 's disease (pd), huntington 's disease (hd), ischemic stroke, and ad. therefore, selective enhancement of the transient calcium increases may provide a promising strategy for developing anti - neurodegenerative diseases, neurogenic agents. it is well known that the rostral subventricular zone (svz) and the subgranular zone (sgz) of the hippocampal dentate gyrus have the capacity of generating neurons into adulthood (gage., 1998). some studies provide evidence for a disruption of npc in an amyloidogenic environment and support findings that neurogenesis is differentially affected among various transgenic mouse models of ad, probably due to variations in promoter cell type specificity, expression levels, and other factors. a more comprehensive analysis of neurogenesis in app transgenic mice showed that while in the molecular layer of the dentate gyrus there is an increased number of npc, in the sgz, markers of neurogenesis are decreased, indicating that in app animals there is altered migration and increased apoptosis of npc that contributes to the deficits in neurogenesis (donovan., 2006). indeed, during aging, there is an age - related decline of adult neurogenesis and this decline is mostly related to decreased proliferation, associated with decreased stimulation to proliferate in aging brains. in the mouse model of ad, there is also evidence for decreased neurogenesis that accompanies the neuronal loss characteristic of the disease (rao., 2005). studies from primates further demonstrate that there is a positive correlation between learning performance and the level of neurogenesis (aizawa. interestingly, studies of human brains and transgenic animal models have demonstrated significant alterations in the process of adult neurogenesis in the hippocampus in ad (donovan., 2006). the decline of neurogenesis in the sgz of the dentate gyrus of different transgenic mouse of ad have been consistently reported with an decrease of the numbers of bromodeoxyuridine, ki-67, and doublecortin positive cells (haughey., 2002 ; dong., 2004 ; wen., 2004 ; one important finding common to several of these app transgenic models is that there is no obvious neuronal dropout in the early stages of pathogenesis (dickson, 2004). in fact, the earliest neuronal pathology before amyloid deposition is the neurogenic deficits in sgz in hippocampus and svz of cerebral cortex (demars. these are accompanied by and cognitive deficits in learning and memory (wang., 2010). all these data suggest that the reduction of generation of new neurons might be a major causal factor for eventually a less number of neurons observed in brain affected by ad. therefore, attenuation the neurogenic decline in subjects potentially suffered by ad may help alzheimer 's patients significantly. these above findings open prospects for new strategies that can increase neurogenesis in normal or pathological processes in the aging brain of ad, and hence decrease memory deficits. studies using this strategy were less successful due to the complexity of brain region delivery, difficulty of survival, migration, differentiation, and integration of the exogenous cells in an already demolished brain, as well as the complexity from immune rejection and ethics issues. to overcome these limitations, moreover, a successful promotion of the endogenous neurogenesis will also improve the local brain microenviroment to a condition which is suitable for generation and survival of new cells (wang., 2007). multiple analyses have documented that dentate neurogenesis is regulated by fibroblast growth factor 2 (fgf-2), insulin - like growth factor 1 (igf-1) and vascular endothelial growth factor (vegf) (shetty., 2005). while the mechanism of age - associated decline in neurogenesis remains to be fully determined, loss in growth factors, fgf-2, igf-1, and vegf, in the microenvironment of the sgz is a prime contributor to the reduced neurogenic potential of sgz (zhang., 2003 ; some results suggest that the dramatic decline in dentate neurogenesis observed as early as middle age could be linked to reduced concentrations of fgf-2, igf-1, and vegf in the hippocampus, as each of these factors can individually influence the proliferation of stem / progenitor cells in the sgz of the dentate gyrus (rao., 2005). thus, several growth factors have been investigated for promotion of neurogenesis in different ad models. although this a one step further than the direct implant of exogenous neural stem cells into brain, one of the major challenges of this approach is the delivery of peptide growth factors to the brain. large molecular weight growth factors do not readily cross the blood brain barrier and thus require direct infusion into the brain via acute or chronic indwelling catheters in the brain. in contrast, small lipophilic molecules that penetrate the blood brain barrier and which induce a controlled targeted proliferation of neural stem or progenitor cells are promising therapeutic strategies (brinton and wang, 2006 ; wang., 2008b). according to the definition of neuroactive steroids, they include all steroids which are active on neural tissue whether or not they are synthesized locally. besides their classical genomic effects, neuroactive steroids can affect neural tissue through a rapid non - genomic effect involving direct binding to the gabaa receptor (belelli and lambert, 2005). studies over the past two decades has demonstrated that the neurosteroid allopregnanolone (ap ; 3-hydroxy-5-hydroxy - pregnan-20-one ; also known as tetrahydroprogesterone ; progesterone 's primary metabolite) is a potent and stereoisomer specific allosteric modulator of the gaba chloride channel complex to increase conductance through the channel which can be protective against seizure activity (brinton, 1994). moreover, ap can induce neurite regression of hippocampal neurons in culture (brinton, 1994). some results indicated that ap is a potent, stereoisomer specific promoter of neurogenesis of both rat hippocampal npc and human cortical neural stem cells. ap induced neurogenesis ranged from 20 to 30% in the rodent npc to 3749% in the human neural stem cells (wang., 2005). our study demonstrated that ap not only increases proliferation of npc of sgz, but also increases neural progenitor cell proliferation in svz in triple transgenic mouse model for ad to the levels similar to that in the age and gender matched non - transgenic control mice (wang. in addition, there is no significant effect on neural progenitor cell proliferation has been observed in non - transgenic control mice (chen. these results indicated that ap only reverses the neurogenic deficits in brain of mice carrying human familial ad mutations, which have been consistently observed by different groups (haughey., 2002 ; dong., 2004 ; wen., 2004 ; zhang., 2007 ; rodriguez., 2008). ap increased expression of genes that promote transition through the cell cycle and proliferation, such as cyclins and cdks including cell division control protein 2 (cdc2), cyclin b and proliferating cell nuclear antigen (pcna) (wang., 2005). ap not only regulated the expression of cell cycle proteins and dna amplification but also drove a complete mitosis of the rodent npc (wang., 2005). it is now well established that the neurotransmitter gaba is excitatory at the embryonic stage. this excitatory action could play a trophic role promoting synapse formation (ben - ari, 2002). it appears that gaba signaling is essential during neural development and proliferation, particularly when interacting with neurosteroids (gago., 2004). gabaa receptor is an ion channel that allows either influx or efflux of chloride ions (cl), depending upon the prevailing transmembrane [cl ] gradient. in mature neurons, ap can bind to a specific site within the gabaa receptor at physiological concentrations (635 nm) (ben - ari., 2007 ; wang., 2008a) to increase chloride influx, thereby hyperpolarizing the neuronal membrane potential, and decreasing neuron excitability (belelli., 2006). because of the high intracellular chloride content in immature neurons, ap provokes an efflux of chloride currents by the binding of gaba - agonists to the gabaa receptors, depolarization of the membrane, opening the threshold of voltage - activated sodium channels and voltage activated calcium channels. the resulting na and ca currents in turn activate high - voltage activated calcium channels. this sequence of events is illustrated by experiments using inhibition by ttx and ni / cd (action potentials blocker). ap affects the gabaa - induced [ca]i transients in a rapid and non - genomic manner (wang and brinton, 2008). (2006) indicate that ap can bind to two sites on the gabaa receptor, one that potentiates, and one that directly activates the gabaa receptor. the potentiating binding site of ap resides in a cavity formed by the -subunit transmembrane domains. the direct activating binding site of ap located among interfacial residues between and subunits and is enhanced by steroid binding to the potentiation site (hosie., 2006). data presented demonstrate that the ap-induced [ca]i rise can be abolished by two gabaa receptor blockers, namely bicuculline and picrotoxin (wang and brinton, 2008), strongly supporting the notion that the ap-induced [ca]i rise is a gabaa receptor - mediated process and most likely through the direct activating binding site. interestingly, cultured hippocampal neurons respond ap with high, low magnitudes and some has no response (wang and brinton, 2008). given that the culture is a mixture of different developing stage of neuronal cells, these differential responses on [ca]i to ap exposure, most likely, reflect the heterogeneity of the gabaa receptor. although heterogeneity of the subunit combination exists, all studies suggest that the effects of ap depend on subunit combinations of the gabaa receptor and the combination is changing during development. therefore, the different gabaa receptor subunit combinations might be the underlying mechanism for the variety of ap-induced [ca]i responses in cultured hippocampal neurons (wang and brinton, 2008). the ap treatment, not only reversed the neurogenesis deficits, it also reversed the cognitive deficits of the 3xtgad mice (wang. the potential mechanism of ap action is likely mediated by transient [ca]i increase (dayanithi and tapia - arancibia, 1996 ; wang and brinton, 2008). it is well documented that calcium plays important roles in variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long - term memory formation. as reported recently by perisse. (2009), during olfactory conditioning ca is both a necessary and a sufficient signal for the formation of protein - dependent long - term memory. an earlier study also indicated that the spatial memory - related increase of protein kinase c isoforms in hippocampal cells is calcium dependent (colombo. interestingly, mice carrying the mutated human app showed lower memory, impaired neuogenesis, and dysregulated cellular calcium homeostasis in hippocampal npc (haughey., 2002). these studies support our proposal, that maintaining a healthy calcium homeostasis in npc by ap may be a key for anti - ad and other neurodegenerative diseases. taken together, we propose that the ap-induced [ca]i transient rise, regulated by the l - type calcium channel and evoked by gabaa receptor, may be the signaling initiation mechanism for ap-induced neuroprogenitor proliferation and cell cycle gene expression. however, [ca]i sustained rise - induced by a oligomers may lead to a formation and deposition, and eventually a calcium regulated cell death. conformational studies using ap to switch the a-induced sustained calcium increase to a transient calcium alteration is on progress. 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. | it was evidenced that impairment of calcium homeostasis is a potential mechanism in the development of alzheimer 's disease (ad). it remains, however, unclear how the calcium signaling are associated with in ad progression. here we review recent studies to discuss the relationship among the signaling of intracellular calcium concentration, neurogenic activity, and ad progression. analyzing these findings may provide new ideas to improve the neurogenic status in pathological processes in the aging brain. |
benign prostatic hyperplasia (bph) is a common condition affecting men older than 50 years of age. the historical gold standard has been transurethral resection of prostate (turp), which is an effective procedure but is still associated with risk of bleeding. factors that influence perioperative and postoperative blood loss include : prostate weight, weight of the resected tissue, operating time, preoperative urine culture, preoperative finasteride treatment, use of acetylsalicylic acid, type of anesthesia, as well as patient age and blood pressure, although some of these associations remain controversial. tranexamic acid (txa) is a potent inhibitor of plasminogen activators and urokinase, thereby preventing clot lysis, and has been shown to be 8-times more effective than epsilon aminocaproic acid (eaca). urine and urothelium contain high concentrations of plasminogen activators that facilitate the lysis of clots. therefore, administration of antifibrinolytic agents might be beneficial in reducing the amount of postoperative blood loss resulting from turp. txa is a synthetic antifibrinolytic drug that prevents the breakdown of fibrin, thereby stabilizing blood clots and reducing blood loss in conditions that promote fibrinolysis. previous studies investigating the beneficial effects of these compounds on turp - associated bleeding have resulted in conflicting conclusions [6, 7 ]. recently, a growing body of evidence has indicated that txa is an effective agent for reducing blood loss in cardiac, orthopedic, and hepatic surgery. txa has also been shown to be of benefit in the treatment of secondary hemorrhage associated with turp [8, 9 ]. in this report we investigated the effect of tranexamic acid on the amount of blood lost during tur - p. its impact on operative time as well as duration of catheterization and hospitalization was also investigated. a prospective and randomized trial was conducted with 40 men requiring turp for obstructive urinary symptoms. the ethics committee of the hospital approved this study and the patients signed their consent on a written form of information. exclusion criteria included a history or evidence of prostate disease other than bph, previous prostate surgery, treatment with any 5ari within 12- months, requirement for treatment with aspirin or nsaids during the restricted periods, and severe medical conditions such as liver disease, bleeding disorders (e.g. hemophilia, von willebrand 's disease, etc.), and unstable cardiovascular problems. all patients had both clinical and laboratory evidence of prostatic enlargement caused by benign prostatic hyperplasia. the patients with even registry numbers were allocated to the treatment group, while those with odd numbers were used as controls and received no treatment. the treatment group received 10 mg / kg txa by intravenous infusion during the first half hour of the operation. patients taking acetylsalicylic acid or warfarin discontinued their treatment seven and two days before surgery, respectively. the volume and hemoglobin concentration of the irrigation fluid, resected prostate weight, and duration of resection were recorded. all turps were performed under spinal anesthesia and by the same surgeon. we used a 26f resectoscope and warm irrigating fluid. surgical blood loss was determined by the amount of hemoglobin in the irrigating fluid using a photometer as described previously. the loss of the hemoglobin per gram of resected tissue at operation time was calculated by dividing the total resected prostate tissue by total hemoglobin loss. differences between groups were analyzed with the two - tailed two - sample t test, mann- whitney u test, or chi - square test, as needed. data of 20 patients treated with txa and 20 control patients were available. in the txa given group, of whom the average age was 67, median prostate weight measured by abdominal ultrasound the average age of the control group was 65 and median prostate weight was 43 g (36.0 - 80.0 g). no statistically significant difference of age and prostate weight were detected between groups (table 1). patient characteristics the mean serum hemoglobin loss on the first postoperative day in the txa group was found to be 0.71 g / dl and was 0.98 g / dl in the control group. even if there was a difference in hemoglobin decrease between the two groups, it was not statistically significant (p = 0.086) (table 2). according to the hemoglobin in irrigating fluid, the mean hemoglobin loss in the txa group was 16.18 g and it was 24.83 g in the control group. the mean hemoglobin loss per gram of resected prostate tissue was 1.25 g in the txa group and 2.84 g in the control group. according to this, total hemoglobin loss in the irrigating fluid and hemoglobin loss per 1 gram of prostate tissue was lower in txa given patients than in the control group (p = 0.018 and p 1 l in 13% of the patients, leading an increased the risk of hemodynamic instability and the need for erythrocyte transfusions. hematuria and clot retention after turp might prolong the hospital time and may even necessitate re - operation. to reduce the perioperative and postoperative bleeding, several different approaches have been tried, including intravenous administration of estrogens, catheter traction, intraprostatic vasopressin, per os etamsylate, fibrin adhesive, phenol solution, and, more recently, finasteride [11, 12, 13 ]. although these approaches have yielded some promising results, no one technique has gained widespread acceptance and incorporation into surgical routine. treatment with finasteride or other antiandrogens before turp was reported to reduce surgical blood loss, but not all studies showed a consistent effect. finasteride is thought to act by mediating androgen - dependent growth factors that regulate angiogenesis in the prostate. txa, in contrast, accumulates in the extracellular space of tissues where it inhibits tissue fibrinolysis [12, 14 ]. postoperative turp - associated blood loss has been correlated with an increase in urinary fibrinolytic activity. there have been studies related to txa usage before turp [8, 9 ]. in these studies, we used txa treatment by intravenous infusion during the first half hour of the operation. during turp, similar results were obtained according to total hemoglobin decrease in the studies of oral txa use. in addition to reduced operative blood loss, we were surprised to observe a statistically significant decrease in the operative time and volume of irrigating fluid required. reduced bleeding during turp as a result of txa treatment may lead to better surgical conditions and, as a consequence, shorter operative times and lower irrigating fluid volumes. this is an intriguing finding, because absorption of irrigating fluid is another concern with turp and is associated with increased operative time and blood loss. none of our 40 patients had clinical signs of irrigating fluid absorption [transurethral resection syndrome ]. the frequency of transurethral resection syndrome varied from 0.18% to 10.9% ; therefore, we would have had a much larger pool of patients to detect any statistically significant differences. several studies have demonstrated that txa treatment does not predispose a patient to thromboembolic complications [16, 17 ]. txa treatment reduced operative blood loss and decreased the operative time and volume of irrigating fluid required. reduced bleeding during turp as a result of txa treatment could lead to better surgical conditions and, as a consequence, shorter operative times and lower irrigating fluid volumes. | introductionpostoperative blood loss after prostate surgery is thought to be associated with an increase in urinary fibrinolytic activity. tranexamic acid (txa) is both a potent inhibitor of plasminogen and urokinase activators and a low molecular weight substance that is excreted unchanged in the urinary tract and can be administered both orally and intravenously. we investigated the effect of txa on the amount of blood loss during transurethral resection of the prostate (turp).materials and methodsforty patients with registry numbers ending in even numbers were allocated to the treatment group ; those ending in odd numbers were used as controls and received no treatment. the treatment group received 10 mg / kg txa by intravenous infusion during the first half hour of the operation, while the control group of patients received no medication. serum hemoglobin was measured before and after surgery. the volume and hemoglobin concentration of the irrigation fluid, resected prostate weight, and duration of resection were recorded.resultsthe mean loss of hemoglobin per gram of resected prostate tissue was 1.25 g in the txa group and 2.84 g in the control group. total hemoglobin loss in the irrigating fluid and hemoglobin loss per 1 gram of prostate tissue was lower in the group of patients given txa than in the control group (p = 0.018 and p < 0.001).conclusionreduced bleeding during turp as a result of txa treatment may lead to better surgical conditions and, as a consequence, shorter operative times and lower irrigating fluid volumes. |
the population we tested included patients treated by physicians within the university of pennsylvania health system, which encompasses several philadelphia - area hospitals. most isolates were from outpatients seen at the hospital of the university of pennsylvania or the presbyterian medical center ; both serve the university of pennsylvania community and populations living in west philadelphia. stool samples were collected as part of the routine evaluation of patients with diarrheal illness and sent in cary - blair transport medium to the clinical microbiology laboratory at the hospital of the university of pennsylvania for processing. campylobacter organisms were isolated and identified to species by using published methods (7). only c. jejuni subsp. each isolate tested represents a single patient. from 1995 through 2001, 404 patient isolates were obtained from routine stool cultures ; 297 (73.5%) were available for susceptibility testing. the age distribution was nearly identical for both sexes (males : median 33 yrs, mean 35 yrs [range 186 yrs ] ; females : medium 33 yrs ; mean 36 yrs [range 895 yrs ]). susceptibility to ciprofloxacin and erythromycin was determined with the e - test (ab biodisk, solna, sweden) method. organisms were tested on mueller - hinton blood agar medium and incubated at 37c in microaerobic conditions. the breakpoints used for resistance were 4 g / ml for ciprofloxacin and 8 g / ml for erythromycin (5). flagellin gene typing (fla typing) was performed by using modified consensus primers, described by wassenaar and newell (8), and digested with ddei as previously described (9). as reported previously, fluoroquinolone - resistant c. jejuni were not detected among 142 patient isolates tested from 1982 to 1992 at our institution (6). two hundred and ninety - seven patient isolates were tested between 1995 and 2001 for susceptibility to ciprofloxacin and erythromycin. resistance rates ranged from as low as 8.3% in 1996 to 40.5% in 2001 (figure 1). in contrast, erythromycin resistance fluctuated between 0% and 5% during the same period ; in 2001 erythromycin resistance was 3.5%. when all isolates tested during the study period are considered, 28.9% of isolates were resistant in the first calendar year quarter, 19.7% in the second quarter, 20% in the third quarter, and 19.2% in the fourth quarter. however, resistance isolates were more frequent beginning in october 2000 and extending through april 2001 (figure 2). number of isolates tested : 198292 (n=142), 1995 (n=24), 1996 (n=48), 1997 (n=61), 1998 (n=37), 1999 (n=22), 2000 (n=48), and 2001 (n=47). number of isolates tested for each quarter : q1 : 13, q2 : 13, q3 : 22, q4 : 10, q5 : 16, q6 : 15, q7 : 12, q8 : 14. a clear bimodal distribution of mics exists, with 96% of susceptible isolates with mics 0.5 g / ml ; except for one isolate, all resistant isolates had mics 32 g / ml. distribution of ciprofloxacin mics in campylobacter jejuni, 19952001. we used molecular typing by restriction fragment length polymorphism analysis of campylobacter flaa to determine whether certain fla types were associated with fluoroquinolone resistance. there were at least four isolates represented in the type (fla types 1, 7, 9, 10, 13, 15, 16, 25, 33, 44, 48, 49, 53, 57, 80, 86). the proportion of resistant to susceptible isolates was no more than 0.25 and ranged from 0.07 to 0.25. we have observed a dramatic increase in fluoroquinolone - resistant c. jejuni in patients treated within our health system from 1995 to 2001 with a resistance rate of 40.5% in 2001. in contrast, erythromycin - resistant c. jejuni has remained at a low rate (32 g / ml. the risk factors for acquiring fluoroquinolone - resistant c. jejuni in the united states have not been defined ; however, foreign travel was identified by smith and colleagues as an important risk factor (for 75% of fluoroquinolone - resistant c. jejuni) in minnesota residents (4). other, unidentified factors were important, however, since the rest of infections were domestically acquired. use of a fluoroquinolone within the month before the collection of the stool sample was also identified as a potential risk factor (4). the increase in fluoroquinolone - resistant c. jejuni from 1996 through 1998 was temporally associated with the licensure of fluroquinolones for use in poultry in the united states (4). several studies from european colleagues noted this temporal relationship between use of fluoroquinolones in animals and resistance among human isolates in the 1980s (3). the reasons for such a dramatic increase in fluoroquinolone - resistant c. jejuni in our population are unknown. we did observe increasing rates of resistance for several quarters during the last 2-year survey period. whether this increase is indicative of foreign travel patterns by our patients future studies should focus on identifying the factors for acquisition of fluoroquinolone - resistant c. jejuni as well as the clinical implications of infection with such strains. some evidence suggests that infection with fluoroquinolone - resistant c. jejuni results in prolonged illness. the duration of diarrhea among patients treated with a fluoroquinolone in the minnesota study was significantly longer if the patient had a fluoroquinolone - resistant infection (median 10 days) versus a fluoroquinolone - susceptible infection (median 7 days)(4). based on national trends and our own local data | fluoroquinolone - resistant campylobacter jejuni has been observed worldwide and is now being seen in the united states. among patients in our health - care system in pennsylvania, fluoroquinolone - resistant c. jejuni were not observed from 1982 to 1992 ; however, resistance increased to 40.5% in 2001. resistance to erythromycin remains at a low level (< 5%). |
sensory integration refers to the neurological process by which the brain organizes sensory information from the body to produce an adaptive movement or behavior.1,2 in the united states, the prevalence of children who typically develop sensory integration dysfunction is 5%13%;3 the estimated prevalence for children having symptoms of sensory processing disorder is 16%.4 the prevalence of sensory integration dysfunction in preschool children in taiwan is 21%28%.5 thus, sensory integration dysfunction is a common developmental problem, with the sensory integration treatment approach most commonly employed in schools.6 according to the model of sensory integration dysfunction described by bundy, sensory integration disorders are heterogeneous problems that fall into several subtypes : postural movement ; bilateral integration sequences ; sensory modulation ; sensory seeking ; and sensory discrimination.7 postural movement may cause problems that include being barely able to engage in antigravitational activities, poor proximal joint stability, low postural tone, and poor balance and endurance.8,9 deficits in bilateral integration and bilateral integration sequence activity may cause inadequate coordination in the hands and feet, and poor performance in such sequencing actions as playing ball and athletic activities that require speed.10 sensory modulation refers to over - responsive reactions or under - responsive reactions, wherein the term under - responsive is understood as having too little response to sensory input, with awareness of a need for strong stimulus before the child can perceive sensory input.11 sensory seeking refers to an intensive craving for sensory stimuli in children.8 sensory discrimination primarily refers to difficulty in interpreting sensory inputs. sensory integration dysfunction may lead to other issues, such as lack of attention, excessive activity,12 or emotional behavior problems.13 the aforementioned problems may affect a child s performance in school and daily life. underlying the study of sensory integration is the understanding that integration relies on a normal developmental sequence. a spiral process of self - actualization is based on the conceptual model of sensory integration proposed by bundy,7 which describes a new, complex upper loop that is established dependently on top of an old, simple lower loop in the model of sensory integration. ayres posited that children older than 9 years still benefited from intervention despite the fact that plasticity of the central nerve system had decreased.7 according to dunn and westman,9 the ability of sensory processing continues to grow after the age of 8 years. there has been much research carried out in america on the effect of age on sensory integration, using such tools as the test of sensory functions in infants,14 the degangi berk test of sensory integration,15 the sensory profile,16 the sensory experiences questionnaire,17 the tactile defensiveness and discrimination test,18 the touch inventory for elementary school - aged children,19 and the touch inventory for preschoolers.20 however, little data has been collected (nor further statistical analysis performed) on the effects of age on the function of sensory integration in taiwanese preschoolers. differences in children s responses to sensation may be attributed to the fact that some children feel pleasure in an activity requiring more vestibular stimulus, whereas other children seem to feel overwhelmed. the features of sensory processing and physiological responses in american children could be different from those in taiwanese children as a result of their respective societal backgrounds. tseng and cheng21 collected sensory profile data from taiwanese children divided into two groups : preschool (36 years old) and school - aged (710 years old). according to sensory integration theory, age difference should affect preschool children ; however, the study by tseng and cheng did not provide enough information on preschool children to warrant the application of the practice of early intervention for children below the age of 6 years in taiwan. thus, the participants in this study were subdivided into two groups, including group 1 that comprised preschoolers (aged 34) and group 2 that comprised the kindergarteners (aged 506). the first question was whether there were differences in the function of sensory integration among preschool, kindergarten, and school - aged children. the second question was whether there were different developmental trends in each of the seven categories of the test of sensory integration function (tsif).22 we expected to obtain more age information, and more detailed information, about the effect of age on sensory integration among taiwanese children than was found in the tseng and cheng study.21 we tested the hypothesis that the improvement of sensory integration function will be significantly greater in the older groups than in the younger groups (ie, group 4 better than group 3, group 3 better than group 2, and group 2 better than group 1) in the seven categories of the tsif. sensory integration is an important developmental process, which must develop in a normal sequence to be successful.8 understanding the role of age in development will greatly enhance the ability to identify effective strategies at suitable ages and support appropriate intervention during developmental stages. a total of 1,000 children were selected for statistical analysis using normative sampling, for developing the test of sensory integration. the exclusion criteria for participants were : (1) receiving special education services or other related services or (2) having developmental disabilities or any neurological dysfunctions, such as seizures, physical disorders, autism, cerebral palsy, or traumatic brain injury. the 1,000 participants included 448 girls (44.8%) and 552 boys (55.2%), (mean = 74.48 months, standard deviation = 25.69 months). study participants were divided into four groups : group 1 included the 343 (34.3%) children aged 36 to 59 months ; group 2 included the 288 (28.8%) children aged 60 to 83 months ; group 3 included the 227 (22.7%) children aged 84 to 107 months ; and group 4 included the 142 children (14.2%) aged 108 to 131 months. since the approach of collecting data was based on the questionnaires, the ethics committee of the university in the middle of taiwan did not consider that their approval was needed before the study began. parents or legal guardians of each child provided informed consent prior to participation, which included consent to publish. the tsif was developed in 2004 to determine sensory integration dysfunction in children aged 3 through 10 years. the tsif subtests are as follows : (1) postural movement (12 items) ; (2) bilateral integration sequences (16 items) ; (3) sensory discrimination (eleven items) ; (4) sensory modulation (21 items) ; (5) sensory seeking (nine items) ; (6) attention and activity levels (18 items) ; and (7) emotional behavior (eleven items).22 each of the 98 items was scored on a five - point likert scale and took approximately 20 minutes to complete. teachers of the participants scored each behavior, as follows : 1 = never (the child never responds in this fashion when presented with the opportunity [0% of the time ]) ; 2 = seldom (the child responds occasionally in this fashion [25% ]) ; 3 = occasionally (the child responds sometimes [50% ]) ; 4 = frequently [75% ] ; 5 = always (the child responds in the manner noted every time when presented with the opportunity [100% ]). the range of possible raw scores on the total scale was 98 to 490, with higher scores indicating poorer performance. internal consistency for the subtests demonstrated a cronbach s alpha ranging from 0.80~0.94 ; test - retest reliabilities for the subtest scores ranged from 0.82~0.94. the seven subscales have good construct validity.23 taiwan was divided into northern, central, and southern areas, in this study. major population cities used for recruitment were taipei, taichung, and kaohsiung, the three most populous cities in the northern, central, and southern parts of taiwan, respectively. taipei has 16 administrative districts, based on the 1990 division criterion, while taichung has eight and kaohsiung has eleven. the study selected one kindergarten and one elementary school in each administrative district by purposive sampling. hence, a total of 70 schools (35 kindergartens and 35 elementary schools) participated in this study. administrators at all schools were telephoned in order to assess their level of enthusiasm for the project. the schools were recruited based on the respondent s interest during the call in which researchers explained the study. after the parents signed a consent form, the teachers received a packet with written instructions, questionnaires, and contact information for the researchers. each evaluator (teacher) had to have been familiar with the tested child for at least 6 months before being allowed to assess the performance of the child. the teachers helped with responses and returned the completed questionnaires. in total, 1,600 children were sampled during school screening for sensory symptoms. of the total sampling, 1,280 questionnaires (80%) were returned, of which 1,000 (62.8%) were valid (with complete answers to questionnaires). the study used the statistical package for the social science (spss 13.0 ; spss, inc, chicago, il, usa) to conduct data analysis. an analysis of variance (anova) was used to identify possible differences among the four age groups (ie, 34, 56, 78, and 910 years) in the categories of the tsif. follow - up univariate analysis f tests of the categories were used to identify which categories contributed to differences between the groups if the variances were homogeneous ; otherwise, two robust tests of equality of means, the welch test and the brown forsythe test, were conducted if the variances were heterogeneous. finally, the games howell tests were used for multiple post hoc comparisons if the variances were not homogeneous. least significant difference (lsd) a total of 1,000 children were selected for statistical analysis using normative sampling, for developing the test of sensory integration. the exclusion criteria for participants were : (1) receiving special education services or other related services or (2) having developmental disabilities or any neurological dysfunctions, such as seizures, physical disorders, autism, cerebral palsy, or traumatic brain injury. the 1,000 participants included 448 girls (44.8%) and 552 boys (55.2%), (mean = 74.48 months, standard deviation = 25.69 months). study participants were divided into four groups : group 1 included the 343 (34.3%) children aged 36 to 59 months ; group 2 included the 288 (28.8%) children aged 60 to 83 months ; group 3 included the 227 (22.7%) children aged 84 to 107 months ; and group 4 included the 142 children (14.2%) aged 108 to 131 months. since the approach of collecting data was based on the questionnaires, the ethics committee of the university in the middle of taiwan did not consider that their approval was needed before the study began. parents or legal guardians of each child provided informed consent prior to participation, which included consent to publish. the tsif was developed in 2004 to determine sensory integration dysfunction in children aged 3 through 10 years. the tsif subtests are as follows : (1) postural movement (12 items) ; (2) bilateral integration sequences (16 items) ; (3) sensory discrimination (eleven items) ; (4) sensory modulation (21 items) ; (5) sensory seeking (nine items) ; (6) attention and activity levels (18 items) ; and (7) emotional behavior (eleven items).22 each of the 98 items was scored on a five - point likert scale and took approximately 20 minutes to complete. teachers of the participants scored each behavior, as follows : 1 = never (the child never responds in this fashion when presented with the opportunity [0% of the time ]) ; 2 = seldom (the child responds occasionally in this fashion [25% ]) ; 3 = occasionally (the child responds sometimes [50% ]) ; 4 = frequently [75% ] ; 5 = always (the child responds in the manner noted every time when presented with the opportunity [100% ]). the range of possible raw scores on the total scale was 98 to 490, with higher scores indicating poorer performance. internal consistency for the subtests demonstrated a cronbach s alpha ranging from 0.80~0.94 ; test - retest reliabilities for the subtest scores ranged from 0.82~0.94. taiwan was divided into northern, central, and southern areas, in this study. major population cities used for recruitment were taipei, taichung, and kaohsiung, the three most populous cities in the northern, central, and southern parts of taiwan, respectively. taipei has 16 administrative districts, based on the 1990 division criterion, while taichung has eight and kaohsiung has eleven. the study selected one kindergarten and one elementary school in each administrative district by purposive sampling. hence, a total of 70 schools (35 kindergartens and 35 elementary schools) participated in this study. administrators at all schools were telephoned in order to assess their level of enthusiasm for the project. the schools were recruited based on the respondent s interest during the call in which researchers explained the study. after the parents signed a consent form, the teachers received a packet with written instructions, questionnaires, and contact information for the researchers. each evaluator (teacher) had to have been familiar with the tested child for at least 6 months before being allowed to assess the performance of the child. the teachers helped with responses and returned the completed questionnaires. in total, 1,600 children were sampled during school screening for sensory symptoms. of the total sampling, 1,280 questionnaires (80%) were returned, of which 1,000 (62.8%) were valid (with complete answers to questionnaires). the study used the statistical package for the social science (spss 13.0 ; spss, inc, chicago, il, usa) to conduct data analysis. an analysis of variance (anova) was used to identify possible differences among the four age groups (ie, 34, 56, 78, and 910 years) in the categories of the tsif. follow - up univariate analysis f tests of the categories were used to identify which categories contributed to differences between the groups if the variances were homogeneous ; otherwise, two robust tests of equality of means, the welch test and the brown forsythe test, were conducted if the variances were heterogeneous. finally, the games howell tests were used for multiple post hoc comparisons if the variances were not homogeneous. least significant difference (lsd) the result of the levene test showed that there were four categories that did not meet the assumption of homogeneity of variance, including : postural movement (levene statistic = 3.78, p = 0.01) ; bilateral integration sequences (levene statistic = 17.61, p = 0.00) ; sensory discrimination (levene statistic = 6.46, p = 0.00) ; and attention and activity (levene statistic = 7.16, p = 0.00). games howell tests were used for multiple post hoc comparisons for those four categories. lsd tests were used for multiple post hoc comparisons for sensory modulation, sensory seeking, and emotional behavior. the anova indicated a significant effect of age on the following subcategories of the tsif : postural movement (f3,996 = 8.48, p < 0.001) ; bilateral integration sequences (f3,996 = 60.85, p < 0.001) ; sensory discrimination (f3,996 = 18.13, p < 0.001) ; sensory modulation (f3,996 = 17.35, p < 0.001) ; sensory seeking (f3,996 = 9.39, p < 0.001) ; attention and activity (f3,996 = 6.68, p < 0.001) ; and emotional - behavioral reactivity (f3,996 = 13.95, p < 0.001) (table 2). in post hoc comparisons of bilateral integration sequences, group 4 performed better than group 3, group 3 performed better than group 2, and group 2 better than group 1 ; older children performed better than younger children. the post hoc comparisons of postural movement, sensory discrimination, sensory seeking, and attention and activity indicated that group 4 performed better than group 2 and group 3, and that group 2 and group 3 performed better than group 1, but there was no significant difference between group 2 and group 3. the post hoc analysis of sensory modulation and emotional behavior showed that the performance of children aged 34 years was poorer than those in any other group (table 2). the result of the levene test showed that there were four categories that did not meet the assumption of homogeneity of variance, including : postural movement (levene statistic = 3.78, p = 0.01) ; bilateral integration sequences (levene statistic = 17.61, p = 0.00) ; sensory discrimination (levene statistic = 6.46, p = 0.00) ; and attention and activity (levene statistic = 7.16, p = 0.00). games howell tests were used for multiple post hoc comparisons for those four categories. lsd tests were used for multiple post hoc comparisons for sensory modulation, sensory seeking, and emotional behavior. the anova indicated a significant effect of age on the following subcategories of the tsif : postural movement (f3,996 = 8.48, p < 0.001) ; bilateral integration sequences (f3,996 = 60.85, p < 0.001) ; sensory discrimination (f3,996 = 18.13, p < 0.001) ; sensory modulation (f3,996 = 17.35, p < 0.001) ; sensory seeking (f3,996 = 9.39, p < 0.001) ; attention and activity (f3,996 = 6.68, p < 0.001) ; and emotional - behavioral reactivity (f3,996 = 13.95, p < 0.001) (table 2). in post hoc comparisons of bilateral integration sequences, group 4 performed better than group 3, group 3 performed better than group 2, and group 2 better than group 1 ; older children performed better than younger children. the post hoc comparisons of postural movement, sensory discrimination, sensory seeking, and attention and activity indicated that group 4 performed better than group 2 and group 3, and that group 2 and group 3 performed better than group 1, but there was no significant difference between group 2 and group 3. the post hoc analysis of sensory modulation and emotional behavior showed that the performance of children aged 34 years was poorer than those in any other group (table 2). in this study, no significant difference was found in postural movements among the children aged 56 (group 2) and 78 (group 3). the children aged 910 years (group 4) dunn and brown used the sensory profile to survey and found significant differences in body position and movement between younger (36 years) and older subjects (710 years), although the effect sizes were very small.24 tseng and cheng showed similar results to dunn and brown, in the performance of body position and movement. the factor of low endurance tone produced no significant difference between younger (36 years) and older subjects (710 years), in taiwanese children.21 wu found that subjects aged 56 performed better in postural movement performance than subjects aged 4.5 however, significant differences were found between children aged 45 years and those aged 68 years, in the study by gregoryflock and yerxa.25 the results of both of these studies5,25 were inconsistent with our study. gregory - flock and yerxa utilized clinical observation and wu utilized computerized clinical observation, both of which can be subjective, to explore children s prone extension. our study employed a widely - used survey scale that evaluated performance according to responses from teachers about the children. magalhaes examined children s ability to perform three bilateral motor coordination tasks : jumping jacks, symmetrical stride jumps, and reciprocal stride jumps.26 huh found that older children moved faster than younger children, when performing both unilateral and bilateral aiming movements.27 the result of our study concurred with results of the aforementioned studies, in that the performance of bilateral integration sequences tended to improve as age increased. the content of sensory discrimination in the tsif includes : proprioception (posture and movement) and vestibular, tactile, olfactory, and thermal discrimination. previous studies focused on the discriminative function of a single sensory system, such as tactile or auditory.28,29 the overall performance of various sensory systems of discrimination lacked attention in previous studies, especially the research and analysis of age effect on sensory discrimination in children. the items in the poor sensory registration test in the sensory profile21 were similar to those in sensory discrimination ; however, age did not have an effect on performance at poor sensory registration. the value of this study lies in the result that as children grow from age 34 years to 56 years or from 78 years to 910 years, they will develop better ability at sensory discrimination, but further development of the ability becomes a flat trend for children from 56 years old to children aged 78 years. much of the research concerning sensory modulation has focused on the effect of treatment, comparison of different disabilities, the relationship between emotion and sensory modulation, or anxiety and sensory modulation. in dunn s research,16 there was a very small difference in the mean scores for sensory modulation across age groups. though the performance of the scoring of oral sensitivity for preschoolers was significantly higher than that of elementary school children, there was no significant difference of the sensory sensitivity between the two groups.21 in a research sample of israeli children, neither age nor gender was found to be significantly different in the hypo- or hyper - responsive responses of the tactile and vestibular systems, between the 3-year - old and 4-year - old participants.30 in this research, 3-year - olds and 4-year - olds were classed into one group, and the children in that group did significantly less well in sensory modulation than those aged 56 years. yet, no significant difference was shown among children of the three oldest groups (ie, those aged 56, 78, and 910 years). early studies of sensory deprivation investigated the sensory seeking behavior of children.31 there has been little study examining sensory seeking by age. it showed that children aged 36 years sought sensory stimulus more than the elementary school children.21 however, there was no age effect in dunn s study.16 in this study, children aged 34 years had a significantly higher frequency of seeking stimulus than did children aged 58 years, and children aged 58 years had a significantly higher frequency than children aged 910 years. previous studies have shown that inhibition will be attained by the age of 6 years.32 the age of 10 may be too mature a stage at which to develop focused attention.33 research indicates that activity level decreases with age, and sustained attention increases with age.34 the subscale of attention and activity of the tsif includes motor inhibition, impulse control, selective and sustained attention, and executive functions. in this study, children aged 910 years scored better than children aged 58 years, and children aged 58 years scored better than children aged 34 years. tseng and cheng demonstrated there was no significant difference in inattention and distraction between preschool and elementary school children.21 our results are more similar to those of klenberg which showed a rapid increase in attention between the ages of 8 and 10 years. significant differences in emotions and social responses were found between younger (36 years) and older subjects (710 years) in the research of dunn and brown,24 and tseng and cheng.21 elementary school children had more positive emotion reaction than did preschool children. those results differed from this research in that in the current work, the frequency of emotional behavior problems in children aged 34 years was significantly higher than in those aged 510 years. this difference might be caused by the differences in how the age groups were divided. from the findings of the seven categories in the tsif, age effects resulted in three developmental trends : (1) an age effect was significant in the four age groups for the subscale bilateral integration sequences ; (2) for children aged 58 years, the function of sensory integration did not present significant progress except bilateral integration sequences. however, there was better development, from group 1 (aged 34 years) to group 2 (aged 58 years) and from group 3 (58 years) to group 4 (aged 910 years), at the subscales of postural movement, sensory discrimination, sensory seeking, and attention and activity ; (3) an age effect was only present between group 1 (aged 34 years) and group 2 (aged 56 years) for the subscales sensory modulation and emotional behavior. although the observations and results were not dramatic, they were predictable, and they provided further confirmation regarding the effect of age on the sensory integration of developing preschool and elementary school children of age 310 years. information for the early identification of sensory integration dysfunction in children in taiwan. using these results, the therapist could screen for the problem of sensory integration dysfunction based on different criteria at different ages and in different categories in the function of sensory integration. for an effective strategy, the therapist could design treatment according to different levels of difficulty for different ages. the limitation of this study was that the three geographical areas selected as representative may be special municipalities, in that they have large populations, and therefore, they may not be representative for all the cities in taiwan. another limitation of this study was that we did not evaluate interrater reliability, to minimize the effect of bias from teachers. we therefore suggest future studies examine the potential role of gender or socioeconomic status in the development of sensory integration. in this study, no significant difference was found in postural movements among the children aged 56 (group 2) and 78 (group 3). the children aged 910 years (group 4) dunn and brown used the sensory profile to survey and found significant differences in body position and movement between younger (36 years) and older subjects (710 years), although the effect sizes were very small.24 tseng and cheng showed similar results to dunn and brown, in the performance of body position and movement. the factor of low endurance tone produced no significant difference between younger (36 years) and older subjects (710 years), in taiwanese children.21 wu found that subjects aged 56 performed better in postural movement performance than subjects aged 4.5 however, significant differences were found between children aged 45 years and those aged 68 years, in the study by gregoryflock and yerxa.25 the results of both of these studies5,25 were inconsistent with our study. gregory - flock and yerxa utilized clinical observation and wu utilized computerized clinical observation, both of which can be subjective, to explore children s prone extension. our study employed a widely - used survey scale that evaluated performance according to responses from teachers about the children. magalhaes examined children s ability to perform three bilateral motor coordination tasks : jumping jacks, symmetrical stride jumps, and reciprocal stride jumps.26 huh found that older children moved faster than younger children, when performing both unilateral and bilateral aiming movements.27 the result of our study concurred with results of the aforementioned studies, in that the performance of bilateral integration sequences tended to improve as age increased. the content of sensory discrimination in the tsif includes : proprioception (posture and movement) and vestibular, tactile, olfactory, and thermal discrimination. previous studies focused on the discriminative function of a single sensory system, such as tactile or auditory.28,29 the overall performance of various sensory systems of discrimination lacked attention in previous studies, especially the research and analysis of age effect on sensory discrimination in children. the items in the poor sensory registration test in the sensory profile21 were similar to those in sensory discrimination ; however, age did not have an effect on performance at poor sensory registration. the value of this study lies in the result that as children grow from age 34 years to 56 years or from 78 years to 910 years, they will develop better ability at sensory discrimination, but further development of the ability becomes a flat trend for children from 56 years old to children aged 78 years. much of the research concerning sensory modulation has focused on the effect of treatment, comparison of different disabilities, the relationship between emotion and sensory modulation, or anxiety and sensory modulation. in dunn s research,16 there was a very small difference in the mean scores for sensory modulation across age groups. though the performance of the scoring of oral sensitivity for preschoolers was significantly higher than that of elementary school children, there was no significant difference of the sensory sensitivity between the two groups.21 in a research sample of israeli children, neither age nor gender was found to be significantly different in the hypo- or hyper - responsive responses of the tactile and vestibular systems, between the 3-year - old and 4-year - old participants.30 in this research, 3-year - olds and 4-year - olds were classed into one group, and the children in that group did significantly less well in sensory modulation than those aged 56 years. yet, no significant difference was shown among children of the three oldest groups (ie, those aged 56, 78, and 910 years). early studies of sensory deprivation investigated the sensory seeking behavior of children.31 there has been little study examining sensory seeking by age. it showed that children aged 36 years sought sensory stimulus more than the elementary school children.21 however, there was no age effect in dunn s study.16 in this study, children aged 34 years had a significantly higher frequency of seeking stimulus than did children aged 58 years, and children aged 58 years had a significantly higher frequency than children aged 910 years. previous studies have shown that inhibition will be attained by the age of 6 years.32 the age of 10 may be too mature a stage at which to develop focused attention.33 research indicates that activity level decreases with age, and sustained attention increases with age.34 the subscale of attention and activity of the tsif includes motor inhibition, impulse control, selective and sustained attention, and executive functions. in this study, children aged 910 years scored better than children aged 58 years, and children aged 58 years scored better than children aged 34 years. tseng and cheng demonstrated there was no significant difference in inattention and distraction between preschool and elementary school children.21 our results are more similar to those of klenberg which showed a rapid increase in attention between the ages of 8 and 10 years. significant differences in emotions and social responses were found between younger (36 years) and older subjects (710 years) in the research of dunn and brown,24 and tseng and cheng.21 elementary school children had more positive emotion reaction than did preschool children. those results differed from this research in that in the current work, the frequency of emotional behavior problems in children aged 34 years was significantly higher than in those aged 510 years. this difference might be caused by the differences in how the age groups were divided. from the findings of the seven categories in the tsif, age effects resulted in three developmental trends : (1) an age effect was significant in the four age groups for the subscale bilateral integration sequences ; (2) for children aged 58 years, the function of sensory integration did not present significant progress except bilateral integration sequences. however, there was better development, from group 1 (aged 34 years) to group 2 (aged 58 years) and from group 3 (58 years) to group 4 (aged 910 years), at the subscales of postural movement, sensory discrimination, sensory seeking, and attention and activity ; (3) an age effect was only present between group 1 (aged 34 years) and group 2 (aged 56 years) for the subscales sensory modulation and emotional behavior. although the observations and results were not dramatic, they were predictable, and they provided further confirmation regarding the effect of age on the sensory integration of developing preschool and elementary school children of age 310 years. information for the early identification of sensory integration dysfunction in children in taiwan. using these results, the therapist could screen for the problem of sensory integration dysfunction based on different criteria at different ages and in different categories in the function of sensory integration. for an effective strategy, the limitation of this study was that the three geographical areas selected as representative may be special municipalities, in that they have large populations, and therefore, they may not be representative for all the cities in taiwan. however another limitation of this study was that we did not evaluate interrater reliability, to minimize the effect of bias from teachers. we therefore suggest future studies examine the potential role of gender or socioeconomic status in the development of sensory integration. there was significant difference between group 1 and group 2 for seven categories of the tsif. significant differences were contributed by the differences from group 1 (34 years) and group 4 (910 years) in five subscales (postural movement, bilateral integration sequences, sensory discrimination, sensory seeking, and attention and activity). | objectivesensory integration progresses along a normal developmental sequence. however, few studies have explored how age difference affects the way sensory integration functions in taiwanese children as they develop. therefore, this study aims to pinpoint the role of age in sensory integration.methoda purposive sampling plan was employed. the study population comprised 1,000 chinese children aged 36 to 131 months (mean = 74.48 months, standard deviation = 25.69 months). subjects were scored on seven subsets of the test of sensory integration function (tsif). an analysis of variance (anova) was used to identify differences between four age groups (ages 34, 56, 78, and 910 years), in the categories of the tsif.resultsanova revealed that age is a significant factor in each of the seven tasks of sensory integration associated with various stages of development. the effect of age was significant in all four groups for the subscale of bilateral integration sequences. the function of sensory integration for the children aged 58 years did not produce statistically significant results for the subscale of postural movement, sensory discrimination, sensory seeking, or attention and activity. for the subscale of sensory modulation and emotional behavior, the effect of age was significant in only group 1 (children aged 34 years) and group 2 (children aged 56 years).conclusionthere was significant difference between group 1 and group 2 for seven categories. significant differences were contributed by the differences from group 1 (34 years) and group 4 (910 years) in five subscales (postural movement, bilateral integration sequences, sensory discrimination, sensory seeking, and attention and activity). there were three developmental trends in the seven categories of the tsif. |
direct pulp therapy is a technique used for the treatment of mechanical or traumatic pulp exposures, without any clinical symptoms of inflammation. removal of irritation, control of infection and biocompatibility of capping material are important factors in treatment outcome.1 also, controlling contamination of the pulp exposure site during the treatment process is another important factor. ultimately, the goal of treating the exposed pulp with an appropriate pulp capping material is to promote the dentinogenic potential of pulp cells.2 the subject of vital pulpal therapy remains controversial, especially regarding which type of pulp dressing provides the most predictable healing. calcium hydroxide (ca(oh)2) has been the standard, but dentin bridge formation can occur under a number of pulp capping materials.1,3,4 application of ca(oh)2 on exposed pulp tissue results in the release of hydroxyl ions with a bactericidal effect, followed by a combination of lytic and coagulation necrosis in the wound surface. the beneficial effect of ca(oh)2 has been regarded, to this bactericidal effect and chemical injury, limited by the zone of necrosis, which caused slight irritation of the vital tissue and stimulated the pulp to defend and repair. on the other hand, hrsted - bindslev and lvschall5 stated that pulp capping with ca(oh)2 induces apoptosis, which is a non - inflammatory controlled cell death mechanism in the underlying pulp, so that the balance of apoptosis and pro - inflammatory response induced by necrosis may have great importance to the prognosis. the opponents of ca(oh)2 for direct pulp capping procedures cite three major causes of failure : a) the porosity of newly produced dentinal bridge ; b) poor adherence to dentin ; and c) inability to provide a long - term seal against microleakage.6 saline solution is one of the most traditional agents used for hemorrhage control in pulp therapies, although it has limited effects on pulp healing.7 on the other hand, many researchers concluded that disinfection of the pulp exposure site and removing the blood coagulum before direct pulp capping has a beneficial effect on pulp healing.3,7,8 for these purposes not only antiseptic agents but also hemostatic agents were used.3,9,10 an iso study conducted by garcia - godoy and murray11 showed that hemostatic treatment had little effect on systemic pulp physiology or healing. they stated local pulp treatment with various hemostatic agents did not alter systemic blood pressure or heart rate during local pulp application. one of the well - known agents that is biocompatible with exposed pulpal tissues is naocl.3,7,9 when used in pulp exposures, naocl acts as a hemostatic as well as a bacteriostatic and/or bactericidal agent.7 alternatively, pameijer and stanley12 stated 2% chx as an effective hemostatic agent in pulp exposure site and recommended 2% chx as a disinfecting agent for pulp capping procedures.13 the study of horsted - bindslev who found only mild inflammatory reactions after application of 0.2% chx in human pulps, supported the idea. swift suggested the use of naocl or chx solution in hemostasis control for a successful vital pulp therapy in their review, which the clinical techniques discussed. recently a new bispyridine antimicrobial compound 0.1% octenidine dihydrochloride (oct) has been developed as a potential antimicrobial / antiplaque agent for use in mouthwash formulations. 1619 it has been shown to be a mucous membrane antiseptic and is also used in severe burns and for wound healing. oct has also been suggested as an endodontic irrigant based on its antimicrobial effects and lower cytotoxicity.2022 the research hypothesis of this study was that antiseptic materials not only impair the healing process of dental pulp capped with ca(oh)2 but also increase the success of the treatment due to their disinfectant and hemostatic properties. in the present study our aim was to evaluate the histopathological effects of a new antiseptic agent besides well - known ones on the repair process of pulp tissue under ca(oh)2 comparatively to saline solution. twenty - eight upper and lower first molar teeth from 7 male wistar rats were used in this study. all procedures were performed under anesthesia using intraperitoneal injection of ketamine (90 mg / kg) and xylazine (10 mg / kg). after disinfection of the operation field with 3% iodine, class i cavities were prepared using a sterile high - speed round dental bur. to ensure standardization, a pinpoint pulp exposure was performed with a dental explorer. four cavities were prepared in each rat in four quadrants (four cavities per rat), and each quadrant represented different experimental groups. in group i, 0.5% sodium hypochlorite (naocl)(gazi university, faculty of pharmacy, ankara, turkey) ; in group ii, 2% chlorhexidine digluconate (chx) (klorhex, drogsan ilalar san ve tic. ankara, turkey) ; in group iii, 0.1% octenidine dihydrochloride (oct) (octenisept, schlke & mary gmbh, wien, austria) ; and, as a control in group iv, 0.9% sterile saline solution was used. all test materials were applied to the respective exposure site with a saturated sterile cotton pellet for 3 minutes. in most cases, if hemorrhage persisted, another sterile cotton pellet saturated with testing material was placed on the exposure site again for 3 minutes. after hemorrhaging was controlled, all exposures were capped with hard setting ca(oh)2 (dycal, dentsply, konstanz, germany), and final restorations were finished with intermediate restorative material (irm) (dentsply caulk, ontario, canada). the animals were sacrificed twenty - one days post - operatively under general anesthesia with an intraperitoneal injection of sodium pentobarbital (50mg / kg). the specimens were fixed in 10% neutral buffered formalin and decalcified in buffered 10% formic acid. after decalcification, the specimens were rinsed under running water for 4 hours followed by dehydration with ascending concentrations of alcohol and then embedded in paraffin blocks. maisson s trichrome staining protocol was performed to evaluate pulp tissue organization, while brown & brenn staining was used for determining bacterial presence in all specimens. sections were examined under the light microscope (eclipse e-600, nikon, tokyo, japan) x20, x40, x100, x200, and x400 magnifications. evaluation criteria for inflammatory cell response are given in table 1 and for tissue disorganization in table 2. the criteria for each specimen were determined and the results were submitted to statistical analysis, using the software statistical packages for social sciences for windows 15.0 (spss inc., chicago, il, usa). the inflammatory cell response and tissue organization scores were subjected to non - parametric kruskal - wallis test to detect the significant differences among the groups and the mann whitney u test was used for two - by - two comparisons. twenty - eight upper and lower first molar teeth from 7 male wistar rats were used in this study. all procedures were performed under anesthesia using intraperitoneal injection of ketamine (90 mg / kg) and xylazine (10 mg / kg). after disinfection of the operation field with 3% iodine, class i cavities were prepared using a sterile high - speed round dental bur. to ensure standardization, a pinpoint pulp exposure was performed with a dental explorer. four cavities were prepared in each rat in four quadrants (four cavities per rat), and each quadrant represented different experimental groups. in group i, 0.5% sodium hypochlorite (naocl)(gazi university, faculty of pharmacy, ankara, turkey) ; in group ii, 2% chlorhexidine digluconate (chx) (klorhex, drogsan ilalar san ve tic. ankara, turkey) ; in group iii, 0.1% octenidine dihydrochloride (oct) (octenisept, schlke & mary gmbh, wien, austria) ; and, as a control in group iv, 0.9% sterile saline solution was used. all test materials were applied to the respective exposure site with a saturated sterile cotton pellet for 3 minutes. in most cases, if hemorrhage persisted, another sterile cotton pellet saturated with testing material was placed on the exposure site again for 3 minutes. after hemorrhaging was controlled, all exposures were capped with hard setting ca(oh)2 (dycal, dentsply, konstanz, germany), and final restorations were finished with intermediate restorative material (irm) (dentsply caulk, ontario, canada). the animals were sacrificed twenty - one days post - operatively under general anesthesia with an intraperitoneal injection of sodium pentobarbital (50mg / kg). the specimens were fixed in 10% neutral buffered formalin and decalcified in buffered 10% formic acid. after decalcification, the specimens were rinsed under running water for 4 hours followed by dehydration with ascending concentrations of alcohol and then embedded in paraffin blocks. maisson s trichrome staining protocol was performed to evaluate pulp tissue organization, while brown & brenn staining was used for determining bacterial presence in all specimens. sections were examined under the light microscope (eclipse e-600, nikon, tokyo, japan) x20, x40, x100, x200, and x400 magnifications. evaluation criteria for inflammatory cell response are given in table 1 and for tissue disorganization in table 2. the criteria for each specimen were determined and the results were submitted to statistical analysis, using the software statistical packages for social sciences for windows 15.0 (spss inc., chicago, il, usa). the inflammatory cell response and tissue organization scores were subjected to non - parametric kruskal - wallis test to detect the significant differences among the groups and the mann whitney u test was used for two - by - two comparisons. the limited area adjacent to the capping material showed inflammatory infiltrate consisting mostly of mononuclear cells. pulp tissue containing this infiltrate consisted of collagen fibers, an irregular odontoblastic cell layer, and plump mesenchymal cells. mild inflammatory cell infiltration beneath the capping material was seen in 6 of 7 samples in groups i, ii, and iii, while 4 of 7 samples in group iv showed the same picture (figure 1). the pulp tissue with loosely arranged thin collagen fibers, prominent odontoblastic cell layer, dilated capillaries, and mesenchymal cells with angular nuclei was suggested as normal histologic appearance and was observed in 4 of 7 samples in groups ii and iii and in 5 of 7 samples in group i (figure 2). pulp tissue morphology was totally disorganized in 6 of 7 samples in group iv (figure 3). however, one sample in group ii presented a band - like structure, void of tubule formation, separating the inflammatory infiltrate adjacent to the material from the pulp tissue. this band - like structure was considered to be a precursoring formation of the dentinal bridge (figure 4). there was no bacterial invasion of the pulp in the brown & brenn histochemical staining. statistical analysis of inflammatory response and tissue organization scores revealed significant differences among the groups tested (p.05). healthy coronal and radicular pulp tissue organization scores indicated that the group i has better pulp tissue organization than group iv and this was significantly different (p.05). it is known that control of pulpal hemorrhage in direct pulp therapies with ca(oh)2 is a very important step affecting pulpal healing. a light pressure on the exposure with a sterile dry cotton pellet for 35 minutes is a traditional clinical practice for hemostatic control in direct pulp therapies. in time today alternatives to wet cotton pellets such as the idea of using antiseptic agents with well - known haemostatic roles and pulp tissue reactions have been discussed to increase the success of vital therapies with ca(oh)2.4,23,24 rat teeth s histological and physiological aspects as well as form and function are very similar to human teeth, so to test new materials and clinical practice they have found wide application areas.25,26 additionally, rat molar teeth was introduced as a realistic model for pulp and dentine usage test of dental materials.27 although saline solution has limited effects on pulp healing, it is one of the most traditional and widely used agents for hemorrhage control in pulp therapies.9,13,2831 therefore, saline solution is used as control group in this study. however, the statistical evaluation of inflammatory response besides healthy coronal and radicular pulp tissue organization for 0.9% sterile saline (group iv) showed a significant difference, indicating an acceptable but relatively inferior success on pulpal response. sodium hypochlorite is recommended as an alternative irrigation solution in several studies because of its well - known bactericidal action.3,7,9 the disinfecting efficiency of naocl depends upon the concentration of undissociated hypochlorus acid (hclo) in solution. hclo exerts its germicidal effect through an oxidative action on sulphydryl groups of bactericidal enzymes. as essential enzymes are inhibited, important metabolic reactions are disrupted, resulting in the death of the bacterial cells.2931 the major disadvantages of naocl are its cytotoxic effects on the periapical tissues and pulp tissue. although various iso studies on non - human primate pulps have demonstrated that use of 2% to 5% naocl presents no in vivo toxicity to primary odontoblasts or to subjacent pulp cells or capillaries, other studies recommend its use at the lower concentration of 0.5% in order to obtain acceptable cytotoxic and bactericidal levels. 3,13,2931 in this study, 3 minutes application time was preferred for hemostatic control so that 0.5% concentration of naocl was selected. the histopathological evaluation results of this study showed normal histologic appearance in most of the samples of group i as well as all groups where antiseptic materials were used (p>.05). however, there was a significant difference between 0,5% naocl (group i) and saline solution (group iv) (p<.05) contrary to the literature review of schuurs,33 who stated that both naocl and saline seem suitable for hemostasis and cleaning of the pulp wound, whereas the effectiveness of a 2% chx solution is questionable. chlorhexidine is a cationic bisguanide that seems to act by adsorbing onto the cell wall of the microorganism and causing leakage of intracellular components. at low chx concentrations, small molecular weight substances will leak out, especially potassium and phosphorus, resulting in a bacteriostatic effect. at higher concentrations, chx has a bactericidal effect due to precipitation and/or coagulation of the cytoplasm, probably caused by protein cross - linking.30 chx has been used in endodontics as an irrigating solution and as an antiseptic and/or hemostatic agent in pulp capping procedures during several studies.7,12,13,17 2% chx was studied for its antimicrobial effect. 7,12,13,29,30 2% chx was selected as test material for this study, according to the encouraging results of pamejier and stanley,12 who found that 2% chx applied immediately after exposure was an effective hemostatic agent. in another study, pameijer13 compared 2% chx and various concentrations of naocl during pulp capping with ca(oh)2, and recommended 2% chx for disinfecting pulp exposure sites. also, ayhan compared 2% chx and 0.5% naocl as an endodontic irrigant on selected microorganisms and found no statistically significant difference between two groups. silva investigated the influence of 0.9% saline solution, 5.25% naocl, and 2% chx on the healing of healthy human pulp tissue capped with ca(oh)2 and found that three hemostatic agents did not impair the healing process following pulp exposure and capping with ca(oh)2 at different time intervals investigated. according to the histopathological results of this study the antibacterial agents may affect clinical and histological success in a positive way. octenidine dihydrochloride has been used in medicine for many years as a soft tissue antiseptic material. in dental practice, the main usage of oct is as a mouth rinse material and the antimicrobial / antiplaque effect thereof has been demonstrated in several studies.1622 it is reported that oct inhibits dental plaque and caries in rats, dental plaque in primates, and in humans.1619 pitten and kramer20 showed that oct has antimicrobial efficiency in oral cavities. on the other hand, shern compared oct and chx as a mouth rinse solution in rats and found no statistical difference between the effect of oct and chx in dental plaque and dental carries formation. in a recent study, dogan reported the results of antibacterial efficacy of common antiseptic mouth rinses and octenidine dihydrochloride against the streptococcus mutans and lactobacillius species. they concluded oct compared favorably with chx and povidone iodine in its antibacterial effects, both in vitro and in vivo. tirali investigated the antibacterial effects of 100% oct, 50% oct and 5.25% naocl and 2.5% naocl solutions on s. aureus, e. faecalis, and c. albicans over a range of time intervals and found the antimicrobial effect of the most effective concentrations of the tested irrigants were ranked from strongest to weakest as follows : 100% octenisept, 50% octenisept, 5.25% naocl, and 2.5% naocl. no data was found in the literature about the usage of oct solutions in direct pulp - capping procedures. moreover, in the view of these studies this antiseptic agent was tested for disinfecting pulp exposure site in this study and found as an acceptable agent for future therapeutic approaches in pulp studies. evaluation results for inflammatory cell response and for tissue disorganization showed no difference between naocl (group i), chx (group ii) and oct (group iii) besides indicating superior pulpal response at 21 days compared to saline (group iv). despite the short - term results of this study, none of the samples showed dentine bridge formation except for one sample from the oct group that was considered to be precursoring formation of a dentinal bridge. additionally, the routine aseptic clinical protocol followed for treatment and finally a hermetic seal with a hard - setting zinc oxide eugenol (irm) resulted with no bacterial invasion to the pulp in all groups. in the literature, particularly for long term, adverse effects were reported about the idea of using irm as a restorative material. in these cases, it was found that the sealing ability of zno - eugenol cement might be based rather on its bactericidal properties, than prevention of microleakage. 36 it was also stated that there is a possibility that the eugenol leaching from the cement diffuses through the ca(oh)2 suspension and liners,33 or the potential effects of reaches the pulp which may result in inflammation and necrosis of the pulp.37 however, guelmann investigated the success of pulpotomies performed on an emergency basis and restored with a temporary restorative material. according to the results of that study, the early failures, may be attributed to the inflammatory status of the pulp. in the long term, failures may be associated with the temporary filling material. in this study only the short term results evaluated so the failures could not be related to temporary restorative material. this result may be due to the malpractice of the clinician upon the same rat. as we have a small number of samples due to ethical considerations this study showed a mild inflammatory cell infiltration besides healthy coronal and radicular pulp tissue organization with no statistical importance among group i, group ii, and group iii, thus indicating affirmative effects in short - term tissue healing. these results signify that oct can be used alternatively to naocl and chx in direct pulp capping with ca(oh)2 without any adverse effects. however, the statistical evaluation of inflammatory response noted that traditional saline application (group iv) was significantly different from the other groups (p<.05) with inferior success on pulpal response and pulp tissue morphology. as a result, although there was a short time interval (21 days) and a small amount of sample in this pilot study ; it can be suggested that the antiseptic materials used in this study, rather than saline solution, created an environment that may affect clinical and histological success in a positive way. | objectives : the objective of this pilot study was to evaluate the effects of three different antiseptic materials on healing processes of direct pulp therapies with ca(oh)2 histopathologically.methods:twenty-eight upper and lower first molar teeth from 7 male wistar rats were used in this study. four cavities were prepared in each rat in four quadrants, and each quadrant represented different experimental groups. in group i : 0.5% sodium hypochlorite (naocl) ; in group ii : 2% chlorhexidine digluconate (chx) ; in group iii : 0.1% octenidine dihydrochloride (oct) ; and in group iv 0.9% sterile saline was applied to the exposure site with a sterile cotton pellet for 3 minutes. after hemorrhage control, the pulps were capped with hard setting ca(oh)2 and, finally, restored with irm. the animals were euthanized at 21 days post - operatively. after sacrificing, routine histological procedures were performed and evaluated statistically with non - parametric kruskal - wallis test among the groups and two - by - two comparisons by using the mann - whitney u test for inflammatory response and tissue organization scores at the confidence interval of 95%.results : there were significant differences in inflammatory response and tissue organization scores between the groups (p.05). healthy coronal and radicular pulp tissue organization scores indicated that the group i has better pulp tissue organization than group iv and this was significantly different (p.05).conclusions : the antiseptic materials used in this study created an environment that, rather than saline solution, may affect clinical and histological success in a positive way. |
bone is a complex tissue that has the ability to heal and regenerate itself, and is continuously in the cycle of remodeling from before birth until death. the process of bone modeling and remodeling typically occurs to help the bone adapt to mechanical forces or to replace microdamaged bone with new, stronger bone. occasionally bone defects will form that are unable to heal on their own, either due to bone disease or trauma. in these cases, bone reconstruction is necessary, which requires osteoproduction (colonization of osteogenic stem cells at defect site), osteoinduction (induced bone formation), osteoconduction (growth of bone on a surface), osseointegration (stable anchorage of an implant achieved by direct bone - to - implant contact), mechanical stimulation, and vascularization [1, 3, 4 ]. in many cases an orthopedic implant is needed in order to stabilize the defect and provide support for new bone to grow. in order for orthopedic surgery to be successful, a strong and lasting connection between the implant and the interfacing bone tissue must be quickly established. a large part of current orthopedics research is centered on designing the material surface to more readily recruit bone forming cells to that interface. the technology and design of materials for bone implants have evolved tremendously over the past 50 years, through what hench and polak defines as three generations of biomedical materials. first - generation biomedical materials (of the 60s and 70s) were designed solely to achieve a suitable combination of physical properties to match those of the replaced tissue with a minimal toxic response in the host. in the late 70s to early 80s, the focus of biomaterials design shifted from solely a bioinert tissue response to include a bioactive tissue response which would trigger a controlled reaction in vivo. bioactive materials reached clinical use by the mid of 1980s for orthopedic and dental applications, including bioactive glasses, ceramics, and composites. resorbable biomaterials (which dissolve into the body) were also introduced to the market, and resorbable polymer sutures became routinely used. at this point, biomaterials properties were beginning to be designed to match the body tissue at the microscale. the third generation of biomaterials has evolved as the search continues for an orthopedic implant technology that provides a stable osseointegration that routinely out - lives the patient. the aim of third - generation biomaterials is that the material is designed in such a way that it would stimulate certain cellular responses at the molecular level. by modifying the surfaces at the molecular and nanoscale levels, researchers have been able to direct cell proliferation, differentiation, and extracellular matrix (ecm) production and organization. great progress has been made in the research behind third - generation biomaterials ; however, the complex mechanisms of the bone cell - surface interactions are yet to be completely understood, and researchers continue to strive to uncover the fully optimized implant material for perfect osseointegration. third - generation, or nanostructured biomaterials research, has uncovered many interesting aspects of cell - surface interaction, and many believe that these materials will provide the optimal implant surfaces of the future. although this review focused specifically on the nanotube surface architecture for bone regeneration, the reader is encouraged to read some interesting and informative literature on the more generic topic of nanostructured surfaces for osteogenesis, including [614 ]. owing to attractive properties such as the high surface - to - volume ratios and size - dependent properties, nanostructured materials have been at the center of a large body of innovative research in science and technology. in particular, nanostructured surfaces are at the focal point of tissue engineering research due to findings which have demonstrated that cells will respond to and be directed by dimensions in the nanometer regime (< 100 nm), even as small as 10 nm height [15, 16 ]. although there are many methods for the fabrication of precisely defined nanostructured surfaces, one of the most simple and inexpensive processes for nanostructure formation is electrochemical anodization. other common procedures for nanostructure fabrication involve a complicated series of steps which often can only be applied to a perfectly flat substrate (i.e., nanolithography). in contrast, electrochemical anodization can be applied to substrates of various 2d and 3d geometries and shapes, as well as sizes ranging from very small to potentially unlimited proportions. this method is also attractive because it is most commonly applied to titanium, which is one of the most widely used materials in bone implant technology. consequently, the review herein is specifically concentrated on variations to the nanotube surface formed by electrochemical anodization in a fluorine containing electrolyte for orthopedic device applications. the formation of titanium oxide (tio2) nanotube arrays via electrochemical anodization was first reported by gong. in 2001. since their discovery, researchers have achieved better control of nanotube formation through such methods as varying electrolyte concentration and ph, inorganic and aqueous solvents, and so forth. extensive control is now possible for nanotube morphology and dimensions including diameter, length, length - to - diameter ratio, wall - thickness, tube shape (conical versus cylindrical), transparency, and even doping. such ability to precisely control nanotube formation via electrochemical anodization has great promise for their utilization in the orthopedics industry. in addition, researchers have been able to apply the same technique of electrochemical anodization to other metals, including zirconium (zr) and tantalum (ta) thus forming nanotube arrays of these metal oxides. the work discussed in this review will focus solely on titanium oxide (tio2) and zirconium oxide (zro2) nanotubes, as well as variations to the tio2 surface and corresponding effects on osteoblast and mesenchymal stem cell growth and function. electrochemical anodization of titanium (ti) or other metal foils involves a two - electrode electrochemical cell with a platinum (pt) foil cathode and metal foil (titanium or other metal of choice) anode which are held at a constant potential (see figure 1). the traditional method of anodization utilizes a hydrofluoric - acid-(hf-) based electrolyte ; however, researchers have also used ammonium fluoride and other chemicals as the fluorine ion source. additionally, the original electrolyte solutions were aqueous based ; since then, it has been found that increased control of nanotube morphology can be achieved using inorganic solvents, and increased mechanical robustness can be achieved using the addition of acetic acid to the hf electrolyte in a 1 : 7 ratio. a trend in nanotube growth, that is, consistent, no matter the electrolyte concentration, is increasing nanotube diameter with increasing applied voltage. the reader is directed to a thorough review by mor. for a detailed mechanistic model of nanotube formation by electrochemical anodization. in 2006, tio2 nanotubes were demonstrated by oh. to significantly accelerate osteoblast adhesion and proliferation and enhance bone mineral formation when compared to nonmodified titanium surfaces. these initial experiments were performed on tio2 nanotubes of ~100 nm diameter and ~300 nm height, with a wall thickness of ~10 nm. reported similar observations in 2007 on the higher adhesion, proliferation rates, and bone forming ability of marrow stromal cells on tio2 nanotoubular surfaces (80 nm diameter, 400 nm height) when compared to those grown on flat titanium surfaces. the intriguing phenomena in these studies of differing cell types triggered further investigation into the effects of nanotube geometry on osteogenic behavior. as was mentioned previously, precise control of the nanotube diameter is possible by varying the applied voltage during anodization. in order to further understand the influence of the nanotube architecture on bone cell behavior, a series of studies were performed in which the lateral spacing of the nanotube system was varied by altering the nanotube diameter from 30, 50, 70, and 100 nm, as depicted in figure 2. the average surface roughness (ra) and contact angle measurements for the corresponding flat ti and various nanotube surfaces are reported in figure 2(b). most bone implant materials are placed in direct contact with both adult bone and bone marrow tissue and thus are exposed to two main cell types : osteoblasts (bone cells) and mesenchymal stem cells (bone marrow cells). in order to develop an understanding of the role of the tio2 nanotube surface in vitro, the behavior of osteoblast cells and mesenchymal stem cells (mscs) was studied on a series of nanotube sizes shown in figure 2. experimental conditions and sample preparation techniques were held constant in both studies, while only the cell type was varied. the cell morphology of both osteoblast and mscs were analyzed using scanning electron microscopy (sem). in both studies, an increase in cell elongation was observed as a function of nanotube diameter, as shown in figure 3. on the flat ti substrate, both cell types are flat, spread out, and round - shaped ; they are somewhat flat and rounded on 30 nm nanotubes, and they become progressively elongated as the nanotube diameter is increased to 50 nm diameter and beyond. it is evident that the nanotubes with diameters of 70 and 100 nm induce extraordinary cell elongation (see red arrows and brackets) after 24 h of culture. in addition, the elongated leading edges of lamellipodia (yellow arrows) of both cell types indicate that the cell morphologies are more mobile on the 70 and 100 nm nanotubular surfaces. the number of cells that adhered to each surface was measured as a function of incubation time. the results of the msc study are shown in figure 4(a), and the results of the osteoblast study are shown in figure 4(c). the highest number of adhered cells in both studies was found on the 30 nm diameter nanotube surface. in addition, the cell elongation of both experiments was quantified by calculating the ratio of cell length to width ; the data of the msc experiment is shown in figure 4(b), and the data from the osteoblast experiment is shown in figure 4(d). as was observed in the sem images in figure 3, both cell types become increasingly elongated as the nanotube pore size increases. however, comparing the cell adhesion versus the cell elongation in figure 4, it is apparent that these phenomena follow opposite trends as a function of nanotube diameter. the results of the osteoblast and msc cell studies indicate that the nanotube dimensions play an important role in the initial cell response to the surface, as indicated by the cell adhesion and elongation behaviors. the mechanism through which a cell senses and attaches to a surface is through surface receptors called integrins, which in fact do not sense the surface, but proteins adhered to the surface. thus, in order to understand the behavior of cells on the nanotube topography, it is important to investigate the manner with which proteins are adsorbed onto the substrates. figure 5 shows scanning electron microscope (sem) images of proteins adsorbed onto the flat ti and 30, 50, 70, and 100 nm diameter nanotube surfaces after 2 hours of incubation in cell culture medium. while the presence of protein aggregates is infrequent on ti, there is an abundance of aggregates on the 30 nm nanotubes. however, the proteins on the larger diameter 70 and 100 nm nanotubes are few and are spaced farther apart. it is evident from these micrographs that the nanotube diameter causes distinct differences in the number and placement of proteins on the surface. the phenomena of cell adhesion versus elongation on the nanotube surfaces can be explained by the pattern of protein adsorption on each of the substrates. the small pore size of the 30 nm surface allows for proteins to adsorb in a more tightly knit fashion, which enables the cells to adhere easily. additionally, the 30 nm substrate does not direct the cells to move / stretch in any specific direction since proteins are everywhere. in contrast, the placement of proteins on the larger (70 and 100 nm) nanotube topographies encourages cell spreading due to the adsorption of proteins only on the nanotube wall rims, thus inducing a fixed distance between proteins and encouraging the cell to spread in order to find adhesion proteins. it is probable that the cells are required to expand their filopodia across larger distances, thus inducing the elongated cell shape. this would also affect the ability of the cell to adhere to the surface, which explains the lower number of adhered cells on the larger diameter substrates. in addition to the observations of cell adhesion and elongation, the msc and osteoblast cell behavior were also analyzed in terms of bone - forming functionality. in the msc study, quantitative polymerase chain reaction (pcr) analysis was performed in order to estimate the relative transcript levels of alkaline phosphatase (alp), osteocalcin (ocn), and osteopontin (opn) gene expressions. the presence of these three genes is important because alp is an enzyme produced by cells which indicates their bone - forming ability, while ocn and opn are proteins found in bone. the data from the pcr analysis, shown in figure 6(a), demonstrates significantly higher gene expression of all three genes on the larger diameter (70 and 100 nm) substrates when compared to the flat ti and smaller diameter (30 and 50 nm) substrates, indicating osteogenic differentiation. similarly, alkaline phosphatase activity of the osteoblast cells was measured on each of the experimental culture substrates. the results from the osteoblast study portray the same trend of increasing alp activity with increasing nanotube diameter (figure 6(b)). these results are evidence that the nanotube diameter causes an upregulation in the markers of bone formation. since the cell elongation and cell functionality followed the same increasing trends as a function of nanotube diameter, it can be speculated that there is a correlation between the two phenomena. interestingly, in addition to the highly elongated cell shape on the large diameter nanotube surfaces, the cell nuclei on these surfaces were also elongated (by 2025%, data not shown). it is likely that the elongation of the cell nuclei is a result of the stretching of the cytoskeletal morphology of the cell. researchers have indicated that cytoskeletal reorganization can cause nuclei distortion, which may promote differences in dna behavior due to mechanical restraints within the nuclei [24, 25 ]. therefore, it is evident that the large diameter nanotube substrate induces cell elongation and thus nuclei distortion, which may cause osteoblast and mscs to produce markers of bone formation and osteogenic differentiation more readily than on a flat substrate. the overall trends of the nanocue effects on osteoblast and stem cell morphology and fate can be summarized by the schematic illustration in figure 7. it was observed that with increasing nanotube diameter cell adhesion growth decreased (solid red line), in a similar manner as protein particle density (broken red line). in contrast, both osteoblast and mscs demonstrated a higher degree of osteogenic differentiation (solid blue line) with increasing nanotube size, analogous to the trend of cell elongation (broken blue line). the findings of these two studies give light to increased understanding of the role of nanostructure dimensions for enhanced biomaterial surface design. however, the nanotube size in these studies was restrained to a maximum diameter of 100 nm due to the limitations of tio2 anodization in an aqueous hydrofluoric acid electrolyte as was used for preparation of these surfaces. anodization methods that enable the fabrication of larger diameter nanotube arrays have been reported, even to as large as 350 nm diameter using an electrolyte consisting of diethylene glycol with low concentrations of hydrofluoric acid (hf). with careful control of anodization protocols, eventual progress may be made which enables the growth of mechanically strong nanotubes with large diameter pore openings. it would be of great interest to further investigate the osteoblast and msc behaviors at diameters beyond 100 nm. the size effect of the nanodimensions of tio2 nanotube surfaces raises the question of whether the trend is unique to the tio2 nanoarchitecture fabricated via electrochemical anodization or if osteogenic behavior would be similar on various sizes of nanotubes of different surface chemistries. in 2009 in which the size selective behavior of mscs was analyzed on zro2 nanotubes as well as tio2 nanotubes coated with a conformal layer of aupd. observed that the different surface chemistries did not affect the diameter dependence of cell adhesion or proliferation. however, a more recent study by the jin lab has demonstrated that various surface chemistries do affect multiple cell types differently, as will be described in detail in the following section. although nanostructured surface geometries have provided exciting findings in the latest biomaterials research, only a few publications have directly compared nanostructures of various surface chemistries. usually, the surface chemistry is held constant, while the nanotopography or nanogeometry is varied. the history of orthopedic implant materials has made it obvious that body tissues respond differently to surfaces depending on the type of foreign material. surface chemical factors are in fact one of the most significant factors on the nanoscale that can affect cell - material interactions. though the majority of related studies compare only nanotextured with nontextured surfaces of the same material, an important addition to this research would be the direct comparison of the same nanostructure with different surface chemistries. it is possible that a unique combination of surface chemistry and nanostructured geometry may provide a balance of defined characteristics towards an optimized cell response. the advantages of the tio2 nanotube surface topography for orthopedic applications have been well outlined in prior sections. since titanium is one of the most commonly used orthopedic materials in use today, it is of great interest to compare any future materials with a well - recognized industry standard. therefore, experiments in the jin lab were designed to provide a direct comparison of flat ti and tio2 nanotubes with the other potential surface chemistries to advance orthopedic implant technology. in order to accomplish this, the concept was implemented of maintaining constant nanotube geometry (i.e., tio2 nanotubes with 100 nm diameter as shown in figure 2(a)), while varying the surface chemistry. carbon films deposited on metal in both its amorphous and crystalline forms have been investigated as potential biomedical materials, mainly because of the chemical inertness of carbon and its naturally occurring presence in the human body [3133 ]. the application of carbon films to materials that are sensitive to wear, such as ti and si, has been a convenient method that has shown significant potential for implant coating applications [3440 ], specifically for orthopedic implants. the effect of a carbon thin film coating on the surface of tio2 nanotubes is thus of interest and will be discussed in this section. the nanotube substrates used in this study were prepared according to standard anodization protocol for the formation of tio2 nanotubes with 100 nm diameter and 1 : 3 aspect ratio as shown in the bottom right corner of figure 2(a). for the carbon - coated comparative surface, the tio2 nanotubes were deposited with a thin, conformal layer of carbon by dc sputter deposition methods in order to obtain a nanotube architecture with a carbon surface chemistry. the carbon coating was only deposited in a very thin layer onto the nanotube wall rims, not altering the nanotube architecture in any way. since cell behavior varies depending on cell type, both osteoblast and osteoprogenitor (mesenchymal stem) cells were plated in this study onto the experimental surfaces in order to assess their behavior in response to the surface chemistry / nanostructure combination. at early incubation time points, the cellular behavior on the surface in vitro includes cell adhesion, growth, and morphological orientation / organization. these three behaviors were assessed via mtt analysis, immunofluorescent cytoskeletal actin staining, and sem examination (data not shown, the reader is directed to ref for full details). the results of each of these assays for both osteoblast and osteoprogenitor cells at early time points (24 and 48 hours) were insignificantly different, which indicates that the carbon versus tio2 surface chemistry did not affect the initial cell response to the surface. both cell types adhered and proliferated equally well on both the tio2 nanotube and carbon - coated nanotube surfaces. the ability of osteoblasts and mscs to mature properly and readily is a vital part of measuring cellular response for bone implant purposes. in this study, the two cell types were cultured for 3 weeks in order to analyze the cells function over time and to determine whether the surfaces were inhibiting or promoting bone function. it should be clarified that the experiments included in this study included the corresponding flat tio2 and carbon substrates as control surfaces. the nanotube substrates were found to enhance both osteoblast and msc cellular response when compared to the flat controls in all aspects of this study, and the data was thus not included. in order to assess the behavior of the osteoblast cells, the alkaline phosphatase (alp) activity was measured, which is an enzyme indicative of bone forming ability. comparative levels of alp activity on each substrate are presented in figure 8(a) as a function of incubation time. in order to visually verify the alp activity quantitative results, the osteoblast cells were also stained using an alp staining kit, as shown in figure 8(b). the alp activity indicates that the bone - forming ability of the osteoblast cells was enhanced on the tio2 surface chemistry when compared to the alp levels on the carbon surface. in contrast, the mscs appear to favor the carbon surface chemistry, as indicated by the enhanced alp activity of the mscs on the carbon nts shown in figure 8(c). additionally, the degree of osteogenic differentiation and maturation of the mscs was analyzed by quantitative pcr analysis for osteocalcin (ocn) and osteopontin (opn). ocn and opn are two major noncollagenous protein components of bone extracellular matrix which are considered markers of osteogenic differentiation as they are solely synthesized and secreted by osteoblastic cells. the graphs of relative amounts for each assay are shown in figure 8(d) ; the relative gene expression of both proteins was enhanced on the carbon surface chemistry when compared to the tio2 chemistry, and the opn was especially upregulated. it is evident from these findings that the carbon surface chemistry causes an increase in osteogenic differentiation and function of the mscs. these results indicate that mscs can distinguish between surface chemistries and crystallinity, as other research groups have also observed. the results of this study indicate that mesenchymal stem cells and osteoblast cells respond differently to remarkably different surface chemistries and seem to have different chemical preferences for optimal cell function. while osteoblast cells are mature bone cells specific to bone tissue, mesenchymal stem cells are highly sensitive, unprogrammed cells and are readily influenced by extracellular factors such as chemical and topographical cues. therefore, it is not surprising that the two cell types have different preferences of surface chemistry. it is possible that the inclination of the mscs for the c - coated surface may be explained by the fact that bone marrow contains many organic carbon - rich components. in contrast, bone tissue is composed of more ceramic / mineral rich components, similar to tio2. perhaps the different cell types are partial to distinct chemistries because of the chemical components of their natural extracellular environments in vivo. it is apparent that tio2 nanotubes as an advanced biomaterial are capable of strongly affecting cell behavior and that even minute changes in the nanotube surface can have substantial results. the fact that such a small range of dimensions as 30100 nm diameter pore openings can alter cell functionality has great promise for researchers in the field of bone regeneration. additionally, since the process of electrochemical anodization provides such facile methods for altering nanotube dimensions, and is applicable to substrates of 2- and 3d geometries, it is imaginable that these findings would be appealing. furthermore, the differing cellular preferences for various surface chemistries indicate the potential for further experiments comparing multiple surface chemistries with the same underlying nanotopography. unique combinations of topography and chemistry could provide the ability to tailor a medical implant surface to a particular tissue type, which would revolutionize the field of regenerative medicine. | the complex mechanisms of the bone cell - surface interactions are yet to be completely understood, and researchers continue to strive to uncover the fully optimized implant material for perfect osseointegration. a particularly fascinating area of research involves the study of nanostructured surfaces, which are believed to enhance osteogenic behavior, possibly due to the mimicry of components of the extracellular matrix of bone. there is a growing body of data that emphasizes the promise of the titanium oxide (tio2) nanotube architecture as an advanced orthopedic implant material. the review herein highlights findings regarding tio2 nanotube surfaces for bone regeneration and the osteogenic effects of minute changes to the surface such as tube size and surface chemistry. |
from the point of view of headache science, the relation between headache and typical women s diseases like endometriosis is interesting because many features of headache, and migraine in particular, suggest a relation to female hormones. from a clinical perspective, it is important to know whether disorders are comorbid, and if so, to investigate the mechanisms for the comorbidity because this can have relevance for the choice of investigations to make and throw light on the pathophysiology and the etiology of both of them. its exact prevalence is unknown because surgery is required for its diagnosis, but it is estimated to be present in 3% to 10% of women of reproductive age and 25% to 35% of infertile women. it often is accompanied by chronic pelvic pain, which occurs in 15% to 24% of fertile women, and active endometriosis is found in about 33% of women with chronic pelvic pain. the prevailing theory for the pathogenesis of endometriosis (sampson s theory) posits that viable endometrium can flow retrogradely through the uterine tubes into the peritoneum during menstruation. accordant with this theory, it has been found that women with increased exposure to menses (early menarche, short cycle length, long menstrual bleeding, and low parity) are at risk. however, these findings are not consistent, and it has been objected that some of them may also be the results, rather than the cause, of endometriosis [2 ]. a particular problem for this auto - transplant theory is that it fails to explain endometriosis in women who have never menstruated. another hypothesis, also compatible with extraperitoneal cysts (eg, in the lungs), is that endometriosis is caused by small defects of embryogenesis. among the headaches, it is particularly for migraine that a relation to sex hormones has been studied. migraine is especially common among fertile women, often starting around the age of menarche and improving after menopause. about half of all women with migraine report an association with menstruation (menstrually related headache), though attacks exclusively in relation to menstruation (pure menstrual migraine) occur in only 5% to 8% of women with migraine [6, 7 ]. menstrual attacks seem to be precipitated by the abrupt fall of estrogen at the end of the luteal phase of the menstrual cycle. although many factors may precipitate attacks, migraine now is mostly understood as a disorder of the brain, but vascular factors probably also play a role in the pathogenesis. although migraine and endometriosis clearly affect different parts of the body, they share some clinical and epidemiological features, most of which probably can be accounted for by the influence of female sex hormones on both disorders. early menarche seems to be a risk factor for both headache [8 ] and endometriosis [2, 9 ]. for headache, it is of interest that age of menarche seems to influence the prevalence of headache, not only among adolescents but throughout life [8 ]. both psychological factors related to early physical maturation, as well as physiological factors related to higher estrogen levels or to increased estrogen sensitivity, have been invoked to explain why headache is more prevalent in females with early menarche. in the case of endometriosis, if the theory of retrograde flow of menstrual blood is true, all conditions (including early menarche) that lead to more menstruations will give a higher prevalence of endometriosis. the fact that both migraine and endometriosis are related to early menarche could indicate that one disorder causes the other, but more likely, early menarche is a factor that increases the risk of both. because menstruation is almost a prerequisite for developing endometriosis and because the hormonal fluctuation related to menstruation is a strong trigger for migraine attacks in women, it would seem logical that the earlier menstruation starts, the more likely it is that one or both disorders will develop. the relation of both disorders to early menarche also could explain the finding that migraine seems to start earlier in women with endometriosis. the common relation to sex hormones probably explains similarities in relation to treatment with gonadotropin - releasing hormone (gnrh) agonists (gnrh - a). a cochrane report has assessed gnrh - a to be effective against pain associated with endometriosis [11 ]. a case study has shown that migraine attacks abated during treatment with a gnrh - a for endometriosis. in a small (n = 5), noncontrolled, open study, treatment with gnrh - a tended to relieve menstrual headaches also in women without endometriosis. in another study on migraineurs without endometriosis, in which medical menopause was first induced with a gnrh - a and the women then received either estrogen add - back or placebo in a blinded fashion, it was found that the gnrh - a with estrogen was superior to the gnrh - a with placebo on all headaches. the estrogen levels were probably stable in all patients, but the effect was most marked in the estrogen add - back group. it may be objected that in this study, the effect may be caused by the estrogen as much as by the gnrh - a. it also should be noted that headache is commonly listed as a side effect of gnrh - a for treatment of endometriosis, but there seems to be less headache with this treatment than with danazol [11 ]. in general, when headache is reported as a side effect, one often may question whether it is caused by the drug or whether it occurs incidentally during the drug treatment. several studies indicate a comorbidity between headache and endometriosis (ie, that they co - occur in the same individual more often than what would be expected from chance). the first study to suggest this those who, during operation, proved to have endometriosis externa (ie, outside the uterine cavity) had significantly more headache than participants with pain from other causes, and headache was almost as common as pelvic pain. this relation has been confirmed in later studies. in a case control study, endometriosis was more common in migraineurs than in the control patients without headache (22 vs 9.6%, p < 0.01). among the women with migraine, headache on 15 days per month or more occurred significantly more often among those with than among those without comorbid endometriosis, and headache - related disability also was significantly higher in migraineurs with endometriosis. the group with migraine and endometriosis had more comorbid conditions, not only those that may be directly caused by endometriosis (eg, dysmenorrhea, metrorrhagia, and infertility), but they also had more depression, anxiety, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, and interstitial cystitis. migraineurs more often had symptoms of premenstrual dysphoric disorder than control patients, but there was no significant difference between the migraineurs with or without endometriosis. this is in accordance with the results from a small treatment study showing a significant positive correlation between the severity of headache and premenstrual syndrome (pms), and the data indicated that pms symptoms were worsened by the presence of headache. control study demonstrated a higher prevalence of headache among 133 women with endometriosis than among 166 control patients (63.9 vs 36.1%, p < 0.001). this difference only concerned migraine (38.3 vs 15.2%, p < 0.01), being most marked for migraine with aura (13.5% vs 1.2%, p < 0.001). virtually no difference was found with regard to tension - type headache (21 vs 22%). an epidemiological association between migraine and endometriosis may represent methodological artifacts, but there also are some potential natural and iatrogenic mechanisms that could explain the association, which will be consider here. looking at the first option, it has been demonstrated that the pain in endometriosis is related to endometrial implants in pelvic tissue. however, many studies have failed to demonstrate a consistent relation between the pain and the anatomy and biochemistry of the implants. in a rat model of endometriosis, it has been shown that the ectopic implants develop both sensory and autonomic nerve supply, mediating the nerve impulses through splanchnic nerves and the vagal nerve to the central nervous system. it is suggested that the implants may lead to central sensitization, causing an increased reaction to afferent impulses also from healthy organs, which can explain the relative lack of association between the localization of implants and the pain. conceivably, this also may apply to sensory input from the head, decreasing the threshold for developing head pain. this mechanism would not be specific for endometriosis, which would be in accordance with the findings of a prospective study of 108 women undergoing laparoscopy for pelvic pain that had lasted at least 6 months. the prevalence of migraine was not higher among women with endometriosis than among those with other pelvic pain [19 ]. however, this theory may not be corroborated by the finding that among patients with endometriosis and headache, no difference was found with regard to headache duration or frequency among patients with mild endometriosis and patients with severe endometriosis. if increased sensitivity constitutes the link between endometriosis and headache, this effect could be mediated by prostaglandins or nitric oxide (no). prostaglandins are thought to play a role in pain transmission and migraine headache by decreasing noradrenergic transmission, sensitizing nociceptors, and promoting neurogenic inflammation [20, 21 ]. no is an important molecule in the regulation of cerebral blood flow [25 ], but it also is involved in angiogenesis and nociceptive processing, and several lines of evidence support its role in both primary headaches and endometriosis [26, 27 ]. however, no study has to date shown that there is a direct link between prostaglandins or no produced by the endometrial implants and migraine attacks, so this would at present seem highly speculative. the reverse possibility, that migraine may somehow cause endometriosis or at least make its detection more likely, also should be considered. migraineurs have been shown to have a lower threshold for pain not only during attacks and in the pre - attack phase [28 ], but also in the interictal phase [29 ]. this could mean that those with headache will suffer from more pain if they develop endometriosis, and thus, increase the likelihood that endometriosis is diagnosed. however, the fact that the presence and severity of migraine does not seem to influence the intensity of dysmenorrhea experienced by the women with endometriosis is not in accord with this theory. interestingly, it also has been hypothesized that migraine may lead to endometriosis in a more direct way. this is based on a study of 50 female migraineurs and 52 age- and sex - matched control patients. surgically confirmed endometriosis occurred more often in the migraine group (30% vs 4%, p < 0.001). in addition, the migraine group had more often a history of self - reported menorrhagia (63% vs 37%), bruising, rectal bleeding, and excessive bleeding after minor trauma (p < 0.01), even after correcting for use of oral contraceptives (ocs), hormone - replacement therapy (hrt), and nsaids. it seems likely that menorrhagia and a slight bleeding diathesis could result in an increased risk of retrograde menstruation, which, according to sampson s theory, could induce endometriosis. however, a weakness of the study is that many patients in the migraine group had endometriosis, making it likely that the menorrhagia can be caused by the endometriosis, at least in some cases. one such factor could be the use of estroprogestins because both headache and endometriosis show a similar, although not identical, relation to use of these medicines. for endometriosis, it is well established that ocs, for instance, represent a valuable treatment option for the disease by relieving pain and possibly preventing the disorder [31, 32 ]. on the other hand, a recent meta - analysis of 18 studies showed that there is an increased risk of endometriosis in present and former users of ocs [33 ]. it also has been demonstrated that the use of ocs and hrt are associated with headache [34, 35 ]. therefore, one could hypothesize that the comorbidity may be due to widespread use of these substances. however, in spite of the positive epidemiological association between oc use and endometriosis, there may not be a direct causal link. in one study, women with and without endometriosis were asked about the reason they started with ocs. women with endometriosis more often started it due to dysmenorrhoea, which was taken as an indication that early symptoms of endometriosis were the cause of the oc use, rather than the opposite [31 ]. similarly for headache, it has been discussed whether the positive association between headache and oc use or hrt is explained by the fact that many women use estrogen supplements to relieve headache. an australian study was performed in a cohort of 931 families with at least two sisters with endometriosis, using 815 independent monozygotic and 457 dizygotic female twin pairs as control patients [36 ]. a significant additive genetic correlation was found, indicating common genetic influences to explain their co - occurrence within individuals. analyses to explore the direction of the causation indicated an underlying genetic disposition common to both disorders. some genetic studies support a role of the estrogen receptor 1 gene in migraine susceptibility, although the exact variant is not identified [37, 38 ]. this receptor also has been reported to be associated with endometriosis [39, 40 ]. it could be a common pathogenetic factor, such as common susceptibility genes, or it could be related to the fact that early menarche is associated with both disorders. also, increased pain sensitivity induced by one of the disorders could make a diagnosis of the other more likely. some observations indicate that increased sensitivity can be related to similarities in no or prostaglandin production. because both are very prevalent disorders, it may be important for the clinician dealing with one of the disorders to take the other into consideration to give the optimal treatment. | headache and endometriosis show some similarities in their clinical and epidemiological features that are probably due to the influence of female sexual hormones on both disorders. epidemiological studies indicate that they are comorbid disorders. however, the nature of the comorbidity is not known with certainty, but a likely explanation may be common susceptibility genes. another possibility is that, because they both are related to pain, increased pain sensitivity induced by one of the disorders may lead to a higher likelihood of developing the other, possibly mediated by nitrogen oxide or prostaglandins. a common link to the widespread use of estroprogestins may seem less probable. for physicians dealing with women with either of these disorders, awareness of the comorbidity may be helpful in the treatment of the patient. |
neonatal diabetes mellitus (ndm) occurs within the first six months of life. depending on clinical outcomes, it is classified into transient neonatal diabetes mellitus (tndm) and permanent neonatal diabetes mellitus (pndm). tndm, which accounts for 50% to 60% of ndm, goes into remission after treatment for an average period of 12 weeks. tndm is usually diagnosed within one month after birth with a median age at diagnosis of 6 days. it is characterized by intrauterine growth retardation (iugr), less frequent diabetic ketoacidosis, requirement of low initial dose of insulin for treatment, and early remission. about 50% of tndm patients, however, may have relapse in adulthood and require lifelong insulin maintenance therapy. the clinical features of tndm and pndm overlap, and the typing is based on clinical remission on follow - up. more than 20 pathogenic genes have been identified in pndm, of which the most common are kcnj11 and abcc8 encoding the kir6.2 and sur1 subunits of katp channel accounting for 40% to 60% [4, 5 ]. mutations in kcnj11 and abcc8 lead to persistence of katp channel in the open state inducing membrane hyperpolarization and impaired insulin secretion. other infrequent mutations include gck, pdx1, eif2ak3, ptf1a, ipf1, glis3, rfx6, slc2a2, slc19a2, foxp3, gata6, mnx1, neurod1, and hnf1b. tndm is caused by defects associated with overexpression of paternally expressed genes in the imprinted region of chromosome 6q24 in 70% cases. three reported defects include (1) paternal uniparental disomy of chromosome 6 (upd6) ; (2) paternally inherited duplication of 6q24 (duplication) ; and (3) maternal hypomethylation at 6q24. about 26% of the patients contain mutations in kcnj11, abcc8, ins, or hnf1b. the genetic etiology remains currently unknown in 40% of ndm cases. in vitro and clinical studies suggest that treatment with oral sulfonylurea can close katp channel and improve glycemic control and neuropsychological development [9, 10 ]. however, 10% of patients with kcnj11 and 15% abcc8 mutations fail to achieve glycemic control when insulin therapy is switched to oral sulfonylureas. therefore, molecular diagnosis is vital not only in accurate typing but also for better prognostication. we summarized the clinical features, molecular typing, treatment, and 1- to 13-year follow - up of 25 cases of ndm in order to better understand the clinical treatment and prognosis. the present study included 25 patients diagnosed with ndm including 18 pndm and 7 tndm from beijing children 's hospital, zhengzhou children 's hospital, and shanxi children 's hospital, from 2001 to 2013. diagnostic criteria for ndm were as follows : (1) age at onset 0.05) (see table 1). direct sequencing identified the most frequent mutations involving katp channel (n = 6) including kcnj11 (n = 5) and abcc8 mutation (n = 1), all of which were identified earlier. the non - katp mutations (n = 6) including ins, eif2ak3 (n = 3), glis3, and slc19a2 were identified and five were confirmed as novel mutations. in the tndm, we found 2 cases harbouring abcc8 mutation and 1 case with upd6. all patients were treated with insulin initially. following stable glucose control with insulin, transition from insulin to oral sulfonylureas finally, three cases (60%) were successfully placed on glyburide ; one switched back to insulin as there was no response to glyburide ; one stopped oral glyburide because of serious gastrointestinal reactions ; and in another case glyburide was not tried because of loss of follow - up. the mean hba1c of pndm during the last visit was 7.2 0.8%, which was similar to that of the infant - onset t1 dm group (table 3). except in 4 pndm cases, the patients who presented with convulsion at the onset showed no further convulsions. among patients with positive mutations, case 1 carrying kcnj11p.r201h mutation had congenital cataract. glyburide therapy was also stopped in case 1 due to gastrointestinal reactions and it was switched back to regular insulin treatment with good glycemic control. case 2 with kcnj11p.r201h mutation and case 3 with kcnj11p.g53s mutation achieved good blood glucose levels with no hypoglycemia with glyburide treatment. case 5 bearing kcnj11p.e229k mutation was lost to follow - up 1 year after diagnosis, while he showed good response to initial insulin therapy but failed to undergo glyburide therapy later. case 6 carrying the abcc8 p.r825w mutation failed to respond to glyburide (0.4 mg / kg / d), and the insulin dose was not reduced. during follow - up, insulin therapy once or twice daily was administered to the child depending on the blood glucose level. case 4 (kcnj11p.v59 m) had intellectual and physical retardation without epilepsy and hence was diagnosed as idend syndrome. this patient was given intermittent glyburide therapy (following parental request) but died of dka at 2 years of age in local hospital. case 8 (glis3 p.f857y) had liver dysfunction but improved by following supportive therapy. case 10 (eif2ak3 p.c532stop) was accompanied with intellectual and physical retardation, short stature, multiple skeletal dysplasia, and hypothyroidism, diagnosed as wolcott - rallison syndrome. case 11 who manifested physical retardation and skeletal dysplasia showed compound heterozygous mutations in eif2ak3. case 14 died of dka at 7 months of age, several days after diagnosis. the patient also showed weight loss and mental and physical retardation with negative results on genetic screening. remission among tndm cases in our cohort was ascertained from 2 weeks to 1 year after diagnosis. none of these patients showed any congenital abnormalities such as macroglossia, umbilical hernia, dysmorphic facial features, hematopoietic dysfunction or abnormal hearing, and heart, liver, or kidney function. no specific features were observed in patient carrying abcc8 mutations and upd6 compared with the other tndm cases carrying negative genetic results. the ndm patients generally presented with infection or decreased responsiveness at the onset, without the typical symptoms such as polyuria, polydipsia, polyphagia, and weight loss. in the present study, there were no differences between pndm and tndm patients in age of onset, birth - weight, and prevalence of dka, making it difficult to clinically distinguish between the two types. the oldest child on follow - up was 5 years old with no recurrence of diabetes. of the patients carrying kcnj11 and abcc8 mutations, there was developmental delay in one patient diagnosed as idend, including one with congenital cataract.. found that patients with mutations in katp channel subunit genes presented with developmental coordination disorders including visual - spatial dyspraxia and attention deficits but not developmental delay or epilepsy. therefore, adults with a history of neonatal diabetes mellitus should be tested for neuropsychological dysfunction and developmental defects. we identified six mutations in katp channel that were previously reported and six non - katp mutations in pndm cases, five of which were not identified until now, and found two katp mutations in tndm cases. three cases were placed on glyburide therapy and 15 cases were on insulin therapy, with good glycemic control in most cases. in this study we identified two cases of p.r201h mutations, which were the most common kcnj11 mutations without neurological abnormalities. these mutations have been confirmed at cpg dinucleotide, resulting in decreased sensitivity of katp channels to atp. glucose stimulation reduces insulin secretion, whereas sulfonylureas stimulate the secretion, explaining the rationale of glyburide therapy. of the two cases, one was responsive to glyburide and the other presented with severe gastrointestinal reactions and parental worries about side effects and therefore discontinued despite recommendations to the contrary. generally, patients with this mutation cause a triad of developmental delay, epilepsy, and neonatal diabetes (dend syndrome), or without epilepsy (intermediate dend (idend) syndrome). the neurological symptoms are attributable to the presence of kir6.2 in nerve and brain tissue. the patient with this mutation in the present study was successfully switched from insulin to glyburide, leading to hba1c level of 6.5%. the fourth mutation was kcnj11p.e229k, which induces ndm without neurological manifestations but was lost to follow - up. as reported, p.e229 and p.g53 mutations cause both pndm and tndm [15, 16 ]. in our study the patient with kcnj11p.g53s underwent low dose glyburide (0.4 mg / kg / d), consistent with previous reports. the mean effective dosage of glyburide is 0.5~0.6 mg / kg / d for sur1 mutations. the parents stopped glyburide due to the side effects. at follow - up, the patient was on insulin therapy and refused to be treated with glyburide. physicians must be cautious before using sulfonylureas as they are not licensed in children and may have side effects. the glyburide transition can only be tried as an inpatient procedure to avoid diabetic ketoacidosis in those young children who may be unresponsive to glyburide and need careful monitoring. parents who carried the same kcnj11 or abcc8 mutations showed no neonatal diabetes mellitus symptoms or past history of abnormal glucose metabolism. the phenomenon suggests that katp mutations have variable clinical phenotypes, with the symptoms varying from tndm or pndm. the mild and transient manifestations during neonatal period were missed, with possible risk of relapse in the future. the glucose metabolism of parents carrying the same mutations as their children needs to be monitored. the success rate of glyburide transition among cases with katp mutations of 60.0% in the present study is lower than that reported from other countries. one reason for the low success rate could be the side effects of glyburide such as nausea and vomiting that affected its clinical application in infants in the present study. diarrhea is the common reported side effects of glyburide but has not been seen in our patients. the failed transitions due to side effects were not reported in other studies, suggesting that chinese children respond differently to glyburide compared with other ethnic groups. case 1 manifesting mental and physical retardation, hypothyroidism, and multiple epiphyseal dysplasia was diagnosed with wrs, as reported by sang.. sanger sequencing yielded a sole heterozygous mutation in this patient, which was inherited from father. the loss of kinase in the catalytic domain resulted in a complete loss of function. the italian pndm patient had heterozygous mutations in both kcnj11 and gck genes, suggesting that ndm may be a polygenic disease. however, no ngs was performed. case 18 was also diagnosed as wrs carrying compound heterozygous mutations of eif2ak3, inherited from father and mother, respectively, with one mutation reported and another deletion mutation resulting in a truncated protein. ndm patients with glis3 gene mutation may also manifest congenital hypothyroidism, glaucoma, liver fibrosis, and polycystic kidney disease. the patient with glis3 mutation showed hepatic dysfunction without liver fibrosis and polycystic kidney disease at onset but eventually died of liver and kidney failure 1 year later in a local hospital. glis3 mutations have been reported to be autosomal recessive resulting in a variable clinical phenotype. slc19a2 gene mutations causing ndm lead to the development of diabetes, deafness and megaloblastic anemia. this syndrome can be ameliorated by thiamine, so it is called thiamine - responsive megaloblastic anaemia (trma). our patient with slc19a2 mutation exhibited moderate normocytic anemia with no hearing abnormalities at diagnosis. another mutation in a non - coding region or a large deletion may be found by sanger sequencing of the whole gene or with multiplex ligation probe amplification technology (mlpa), respectively. the classification of tndm and pndm should be reconsidered. a diagnosis of diabetes in parents who carried the mutations can not be excluded. we need additional and longer follow - up of cases to establish a tndm diagnosis or pndm remission. diarrhea is one of the manifestations of ipex (immune dysregulation, polyendocrinopathy, enteropathy, and x - linked syndrome), which is caused by foxp3 mutation. ipex may also present with autoimmune thyroid disease, exfoliative dermatitis, and sepsis caused by immune dysregulation. the mutations in katp channel accounted for 33.3% of pndm, including 27.8% in kcnj11 mutations and 5.6% in abcc8 mutations, similar to the reported data. we diagnosed two cases of wrs (11.2% of all pndm cases), which is now recognized as the most frequent cause of pndm in consanguineous children [23, 24 ]. in addition, rare gene mutations (glis3, slc19a2, etc.) also were associated with specific clinical manifestations. therefore, in view of the high mutation rate of kcnj11 in pndm and high correlation between genotype and phenotype, we suggest screening for kcnj11 mutations first in ndm cases, followed by abcc8 screen and genes associated with specific complications. pndm children on insulin and glyburide therapy were found to have good glycemic control (mean hba1c 7.2%) during follow - up, which is similar to infantile onset t1 dm group. it was probably associated with younger age at onset, need for a lower insulin dose, and better residual pancreatic cell function. the onset age of pndm and t1 dm is usually different, although the duration of illness is comparable, which is the most important factor affecting the hba1c level. the syndrome is associated with giant tongue, umbilical hernia, facial deformity, kidney abnormalities, congenital heart disease, hypothyroidism, and intrauterine growth retardation (> 95%). array - cgh could be used to detect upd6 and duplication simultaneously, so it may be a cost - effective genetic analysis method for tndm cases. in our study, all the tndm cases did not exhibit the specific manifestations mentioned above. recurrence of tndm resulting from kcnj11, abcc8, and 6q24 mutations might respond to treatment with sulfonylurea [3, 25 ]. it should be noted that the pathophysiological mechanism of 6q24 mutations is not clear and thus the most appropriate treatment remains unclear. in the present study, the genetic etiology could not be determined in 50% of pndm and 57% of tndm cases. however, no maternal hypomethylation at chr6q24 was detected, which may have affected the mutational analysis of the tndm cohort. most ndm patients achieved good glycemic control (hba1c < 7.5%) and there was no significant difference when compared to infantile onset t1 dm. | aims. to study the clinical features, genetic etiology, and the correlation between phenotype and genotype of neonatal diabetes mellitus (ndm) in chinese patients. methods. we reviewed the medical records of 25 ndm patients along with their follow - up details. molecular genetic analysis was performed. we compared the hba1c levels between pndm group and infantile - onset t1 dm patients. results. of 25 ndm patients, 18 (72.0%) were pndm and 7 (28.0%) were tndm. among 18 pndm cases, 6 (33.3%) had known katp channel mutations (katp - pndm). there were six non - katp mutations, five novel mutations, including ins, eif2ak3 (n = 2), glis3, and slc19a2, one known eif2ak3 mutation. there are two abcc8 mutations in tndm cases and one paternal upd6q24. five of the six katp - pndm patients were tried for glyburide transition, and 3 were successfully switched to glyburide. mean hba1c of pndm was not significantly different from infantile onset t1 dm (7.2% versus 7.4%, p = 0.41). conclusion. pndm accounted for 72% of ndm patients. about one - third of pndm and tndm patients had katp mutations. the genetic etiology could be determined in 50% of pndm and 43% of tndm cases. pndm patients achieved good glycemic control with insulin or glyburide therapy. the etiology of ndm suggests polygenic inheritance. |
neuralgic amyotrophy (na)-also known as parsonage - turner syndrome or brachial plexus neuritis - is an under - recognized but distinct clinical syndrome, with a characteristic clinical presentation of an acute, severe neurogenic pain in the shoulder or arm lasting for several days or weeks, followed by muscle weakness, atrophy, and sensory loss as the pain diminishes.13171920212223) the pain is a hallmark of na and typically relentless and severe [numerical rating scale (nrs)>7].1721) there is no successful treatment of na yet and the initial pain at the onset of an attack is only partly relieved by traditional analgesics.1721) although spinal cord stimulation (scs) has been known as an accepted, effective therapy for patients with chronic neuropathic pain such as complex regional pain syndrome (crps) type i as well as in a variety of other neuropathic conditions,127121524) its effectiveness against the neuropathic pain of na was not reported. herein we describe a 35-year - old woman with intractable neuropathic pain from na who responded to scs.61524) a 35-year - old female presented with an eight - week history of a severe, unrelenting pain in the left palm and radial four fingers, medial forearm, and in the shoulder pain waking her from sleep. the pain was described as dull, crushing, and deep pressure - like and of an extreme severity (8 - 9/10 on nrs). the pain made the patient sit on the table constantly holding her arm close to her body, keeping it immobile. eight weeks ago, she woke up in the morning with a severe pain in her left shoulder and hand and this pain was unlikely any pain she experienced before. the pain worsened at this day and become constant and unrelenting since then and it was heavier at night. a weakness in her left hand progressively developed 2 weeks after the onset of pain. the electromyography study suggested an incomplete brachial plexopathy. on examination, a moderate tenderness in the left shoulder with a moderate weakness [manual muscle testing (mmt) grade 3 ] of the left hand grasping and finger movement was observed. the sensory examination showed patch areas of hypesthesia, paresthesia, and mechanical allodynia to light touch and pressure in her left shoulder, medial forearm, thenar side of the palm and in four fingers which corresponded to the pain sites (figure 1a). her nrs at examination was (8/10, nrs) and the pain was more severe at night (9/10, nrs). the mri of the left brachial plexus showed a diffuse swelling, increased signal intensity, and an enhancement of whole trunks of the left brachial plexus and its divisions suggesting a brachial plexopathy (figure 1b and c). there was a marked asymmetrical uptake in the blood pool phase of the three - phase bone scintigraphy (figure 1d) and skin temperature asymmetry on digital infrared thermal imaging (figure 1e). after admission for pain control, the amount of daily medication was increased to gabapentin 2,400 mg, ir - codon 40 mg, oxycodone 40 mg, amitriptyline 20 mg, and 50 mcg / hr transdermal fentanyl. however, the pain relief was not satisfactory and the patient got an injection of fentanyl 10 mg five times a day as needed. considering the chronicity and severity of neuropathic pain, a temporary trial of scs was performed (approximately 10 weeks after onset of pain) with a cylindrical electrode (octrode, plano, tx, usa) at the level of c3 - 5 (figure 2a). the severe dull, crushing and deep pressure - like spontaneous pain and the evoked pain (mechanical allodynia) in the arm and hand was alleviated for about 50% (contact polarity 3 - 4 +, 100 usec, 100 hz, 1.5 ma). she assessed the effect of scs as fairly successful and expressed the pain intensity (4 - 5/10, nrs). during the temporary stimulation period of 21 days, she was satisfied with the analgesic efficacy of scs and wanted to have a chronic stimulation. approximately 12 weeks after the onset of severe pain, a chronic scs system was implanted through a paddle lead scs (penta and eon - mini rechargeable, st. after one week of adjustment of the stimulation parameters (1 - 4 +, 400 usec, 90 hz, 1.4 ma), she finally discontinued a nighttime injection of fentanyl and switched into ir - codon 10 mg as needed. the analgesic efficacy of scs was more effective in controlling pain and allodynia in the medial forearm, palm and 2nd, 3rd, 4th fingers (more than 60% relief, subjective assessment). the effectiveness of chronic scs was fairly consistent during the follow - up of 12 months and she evaluated her pain as 4 (daytime)-5 (nighttime) in on an 11 point nrs. at the last follow - up of 12 months after the onset of pain, the patient still suffered a serious, chronic pain (fluctuating 3 - 6/10, nrs) and grade iv mmt weakness of left hand. her medication at the last follow - up was gabapentin 1,200 mg, oxycodone 20 mg, amitriptyline 10 mg, and ir - codon 20 mg per day. na, which was first described by dreschfeld4) in 1886 as a distinct clinical syndrome, is characterized by attacks of neuropathic pain and subsequent patch paresis in the upper extremities. the etiology of idiopathic na remains unknown and an immune - mediated process seems to garner the most support currently.111425) a hallmark of na is a sudden, severe painful onset and the patch distribution of motor, sensory and autonomic symptoms.1727) any part of the brachial plexus and the lumbosacral plexus can be involved, with any combination of motor and sensory impairment.1721) a bilateral involvement of the brachial plexus occurs in approximately 30% of patients ; clinical features are commonly asymmetric in presentation.21) the upper trunk of the brachial plexus is most usually involved, but any part of this plexus can be affected too. also painless attacks can occur.1721) in 96% of patients, na presents with acute, severe pain in the upper extremities, neck and/or trunk, which usually causes the individual to wake up early in the morning. the pain then increases to its maximum severity over the next few hours.21) typically is the pain relentless, worse at night and is unlikely anything the patient has ever experienced before, with pain scores of at least 7 being assigned on the numerical scale of 0 to 10.19) this initial pain lasts for 4 weeks on average, but disappears in 5% of cases within 24 hours and lasts for at least 2 months in 10% of individuals.21) subsequently, at least 75% of patients will go on to develop an additional type of pain, possibly because of hypersensitivity of the damaged nerves to mechanical stretch or maintained posture, shooting or radiating pains to the arms or trunk that dissipate over a period of weeks to months. additionally, two - thirds of individuals develop a musculoskeletal pain at the origin or insertion of the paretic or compensating muscles, especially in the periscapular and cervical - occipital regions.182021) the treatment of pain and residual sequele of a na is directed to a supportive management. adequate analgesia including the use of opiates in the acute painful phase and appropriate physical therapy and rehabilitation for shoulder paresis and glenohumeral instability in the chronic phase are the cornerstones of management.172123) the prognosis of na was traditionally thought to be positive, with full recovery occurring in 80% to 90% of patients 2 to 3 years following the onset of symptoms.316) however, subsequent studies showed that the overall recovery was less favorable than usually assumed.172123) persistent pain and paresis was experienced in approximately two - thirds of patients that were followed for 3 years or more, with a marked effect on their daily life and employment.5172123) scs is known to be a safe and effective treatment option for selected patients with medically refractory chronic pain syndrome such as failed back surgery syndrome or crps, and peripheral neuropathic pain.127121524) scs involves the placement of electrodes in the epidural space and production of an electrical current by means of a pulse generator. the analgesic mechanism produced by scs is believed to work by the gate control mechanism and modulation of excitatory and inhibitory neurotransmitter release in the dorsal horn.924) although scs has been reported to be effective in various kinds of neuropathic pain,127121524) the effectiveness of scs was not reported in the treatment of a typical neuropathic pain of na. the reason why we performed the trial scs in this patient is simple ; we wanted to relieve an extraordinary prolonged period of severe pain refractory to maximal medical treatment (nrs>7/10). therefore, we adopted a temporary scs as a salvage procedure within a desperate condition in our case. this kind of temporary scs treatment has already been reported in the acute and subacute phase of postherpetic neuralgia.1026) another reason for temporary scs was that the typical neuropathic pain nature of na. although a typical cutaneous manifestation of crps-1, such as edema and sudomotor sign, was absent, the symptoms and signs and some ancillary investigations were comparable to those of typical crps-1.8) further controlled studies are needed to evaluate the efficacy of early scs in the severe neuropathic pain of na. temporary scs was effective in achieving an adequate analgesia in the acute phase of na and chronic scs was also useful to control the chronic pain. however, na has been known to spontaneously resolve and we think scs trial should be limited to selected patients with pain is notoriously refractory to conservative management. | the aim of this paper was to report the effect of temporary and chronic spinal cord stimulation for refractory neuropathic pain in neuralgic amyotrophy (na). a 35-year - old female presented with two - months history of a severe, relentless neuropathic pain of the left shoulder, forearm, palm, and fingers. the neuropathic pain was refractory to various medical treatments, including nonsteroidal anti - inflammatory drugs, opiates, epidural and stellate ganglion blocks, and typically unrelenting. the diagnosis of na was made with the characteristic clinical history and magnetic resonance imaging. the patient underwent a temporary spinal cord stimulation to achieve an adequate pain relief because her pain was notoriously difficult to control and lasted longer than the average duration (about 4 weeks on average) of a painful phase of na. permanent stimulation was given with paddle lead. the neuropathic pain in her na persisted and she continued using the spinal cord stimulation with 12 months after development of na. the temporary spinal cord stimulation was effective in a patient with an extraordinary prolonged, acute painful phase of na attack, and the subsequent chronic stimulation was also useful in achieving an adequate analgesia during the chronic phase of na. |
phenols are aromatic compounds that are characteristic pollutants in wastewater and effluents from chemicals, petrochemicals, pharmaceuticals, textiles, and steel industries. the unwholesome and environmentally unacceptable pollution effects of the phenolic effluent have been reported worldwide. phenol contaminants are relatively soluble in water and accumulate in soil, resulting in extensive surface water, ground water, and soil contamination owing to its severe toxicity. currently removal of phenol effluents from contaminated sites has been a major environmental concern. different techniques have been applied to remove phenolic compounds from polluted areas [48 ]. however, among all, biodegradation process offers the more opportunities to completely destroy the pollutants if possible or at least to transform them to innocuous substance, it posses relatively low cost, no chemicals used, and high public acceptance. research on microbial degradation on phenols has intensified in recent years because it is the sustainable ways to clean - up contaminated environments. microbes will adapt quite rapidly and grow at extreme condition using hazardous compounds as carbon and energy sources, microbes can adapt rapidly to extreme conditions in waste streams. important examples include phenol, chlorophenol, chlorobenzene, chloroalkanes, atrazine, and nitroaromatics. a wide variety of microorganisms are known to be capable of metabolizing or mineralizing phenol under aerobic and/or anaerobic conditions. many microbes belonging to the genus of pseudomonas have been reported as good degraders of phenol. the pure culture of pseudomonas strains are often utilized for metabolic pathway studies evaluating the degradation of many aromatic compounds such as phenol [13, 14 ]. in pseudomonas, many induced enzymes are nonspecific, and the metabolic pathway contains a high degree of convergences. the convergence of catabolic pathway allows for the efficient utilization of a wide range of growth substrates, while the nonspecificity of the induced enzymes allows for the simultaneous utilization of several similar substrates without redundant genetic coding for enzyme induction. a typical pathway for metabolizing an aromatic compound like phenol is to dihydroxylate the benzene ring to form a catechol derivative and then to open the ring through ortho- or metaoxidation. catechol is oxidized via ortho - cleavage pathway by catechol 1,2-dioxygenase, or by metapathway to 2-hydroxymuconic semialdehyde by catechol 2,3-dioxygenase (figures 1 and 2). the final products of both the pathways are molecules that can enter the tricarboxylic acid cycle [16, 17 ]. catechols are cleaved either by ortho - fission (intradiol, i.e., carbon bond between two hydroxyl groups) or by a metafission (extra diol, i.e., between one of the hydroxyl groups and a nonhydroxylated carbon) as given in figures 1 and 2. a potential strain is necessary for the effective degradation to proceed at a faster rate. considering the potential of pseudomonas strains, the present study was envisaged with the following objectives : isolation, screening, and identification of potential phenol degrading isolates and determination of phenol degradation pathway. the minimal medium used in the degradation studies, adapted from goulding., contained (g / l) k2hpo4, 4.36 ; nah2po4, 3.45 ; nh4cl, 1.0 ; mgso46h2o, 0.912 ; trace salts solution 1 ml / l. the trace salts solution was prepared separately in distilled water and was stored in a dark bottle for 68 weeks. the trace salts solution contained (g/100 ml) cacl22h2o, 4.77 ; feso47h2o, 0.37 ; cocl26h2o, 0.37 ; mncl24h2o, 0.10 ; na2moo42h2o, 0.02. the soil samples were collected aseptically from different sites under three inches of depth from the surface soil. one gram of soil was suspended in 9.0 ml sterile distilled water, agitated for mixed well. after dilution, 0.1 ml suspension was spread over pseudomonas minimal agar plates (ph 7 0.1) containing 200 ppm of phenol as sole carbon and energy source. a number of bacterial colonies showing on plates were selected, streaked twice on pseudomonas minimal agar plates by replica plate method for purification. when a streaking produced only one type of colony in a plate, it was considered to be pure culture. for obtaining high potential isolates a preliminary screening was done employing pseudomonas minimal agar plates with 500 ppm concentration of phenol. among the five high tolerant bacteria, five microbial strains (designated as pu1, pk2, pk3, pk4, and pf6) obtained as described above were maintained as pure culture over minimal agar slants at 4c for further studies. thus the most tolerant isolate was finally characterized on the basis of morphological, cultural, and biochemical properties [2325 ]. the selected bacterial isolate pu1 was identified by morphological and biochemical characterization as per bergey 's manual of systematic bacteriology [26, 27 ]. bergey 's manual of determinative of bacteriology and abis6 online software (accessed on 20 january 2011) were used as a reference to identify the isolate. isolate pu1 was used to inoculate in nutrient broth (1.3%, w / v) and incubated at 37c for 24 h with agitation at 120 rpm. the harvested cells were centrifuged at 5000 rpm for 10 minutes and washed twice with 0.01 m sodium phosphate buffer and final pellet resuspended in the same buffer. five ml of bacterial suspension (10 to 10) was used to inoculate 95 ml sterile minimal medium containing appropriate phenol concentration in 250 ml conical flasks. after inoculation, flasks were incubated in an orbital shaker at 120 rpm at 37c. samples were aseptically removed at regular intervals and analyzed for cell growth and phenol removal. cells were removed by centrifugation at 5000 rpm for 10 minutes and the supernatants were analyzed for phenol removal. growth was monitored by using optical density measurement at 660 nm (od660) using uv - spectrophotometer (shimadzu 1601). phenol concentrations were determined by using the 4-aminoantipyrene colorimetric method based on the procedure detailed in standard methods for the examination of water and wastewater. cells were grown on phenol (600 ppm) which was harvested by centrifugation (4000 rpm, 10 min) and the resulting pellet was washed twice with 0.33 m tris - hcl buffer (ph 7.6). the cells were broken by sonication for 4 minutes (30 sec on, 30 sec off) and centrifuged at 12000 rpm, 4c for 20 min. the cell - free extract was kept on ice and assayed as soon as possible for catechol dioxygenase activity using the method of feist and hegeman. the ortho - cleavage product of catechol is catechol 1,2-dioxygenase it was measured by following the formation of cis, cis - muconic acid. the following reagents were added to a quartz cuvette : 2 ml of 50 mm tris - hcl buffer (ph 8.0) ; 0.7 ml of distilled water ; 0.1 ml of 100 mm 2-mercaptoethanol, and 0.1 ml of cell - free extract. the contents of the cuvette were mixed by inversion and 0.1 ml of catechol (1 mm) was then added and the contents mixed again. the absorbance read at 260 nm over a period of 5 min and cis, cis - muconic acid formation was indicated by the increase of absorbance. catechol 2,3-dioxygenase activity was measured by following the formation of 2-hydroxymuconic semialdehyde, the meta cleavage product of catechol. the following reagents were added to plastic cuvette : 2 ml of 50 mm tris - hcl buffer (ph 7.5), 0.6 ml of distilled water, and 0.2 ml of cell - free extract. the contents were mixed by inversion and 0.2 ml of catechol (100 mm) was added and mixed with the contents. 2-hydroxymuconic semialdehyde production was followed by an increase in absorbance at 375 nm over a period of 5 min. the enzyme activity was calculated by using the following equation : (1)activity (moles product formed / min) = eclvodmin. molar extinction coefficient for catechol 1,2-dioxygenase, e260 = 16,800 l / mol / cm and for catechol 2,3-dioxygenase, e375 = 14,700 mol / l / cm. specific activities were expressed as units per milligram of protein calculated by the following equation : (2)specific activity (moles / min / mg) = activitytotal protein. the protein concentrations in cell - free extracts were determined by the method of lowry., with bovine serum the experimental data was analyzed using sigma plot 7 (2001) and microsoft office excel 2007. sample soils were cultivated on pseudomonas minimal media containing phenol as sole carbon and energy source at 37c. five phenotypically different colonies were picked from the plates and translated to fresh pseudomonas minimal agar plates with phenol for purification. as many as five bacterial isolates were purified and inoculated to pseudomonas minimal medium containing phenol (800 ppm) as the sole carbon and energy source. the growth of the bacteria in terms of absorbance, and the extent of phenol degradation were monitored up to 3 days. it could be seen that the biomass growth and phenol removal by four isolate pu1 was higher than other four isolates. hence, the results of phenol degradations were reported up to 3 days (figure 3). the isolate pu1 was short rod and round in shape, stained gram negative, and was positive for catalase and oxydase activity. isolate pu1 also gave positive result for the voges - proskauer test and was able to hydrolyze gelatin. the strain utilized sugar glucose, fructose, sucrose, xylose, and sorbitol, but did not utilize rhamnose, arabinose, and lactose. based on the morphological, biochemical, and carbohydrate utilization tests, it was identified as pseudomonas fluorescens [28, 29 ]. this strain was allowed to grow for 72 hours, in the pseudomonas minimal medium containing phenol at different concentration as the sole source of carbon and energy. this isolate completely degraded phenol up to 600 ppm in 24 hours and corresponding bacterial cell growth (i.e., od at 660 nm) was 0.873 at 24 hours from the initial cell density 0.110. after 24 hours the cell density was recorded to be decreased with time (figure 3) due to absence of carbon source. pseudomonas fluorescens pu1 also completely degraded 800 ppm and 1000 ppm of phenol in 72 hours whereas it degrades about 99 percent of phenol in 48 hours as well. the highest cell growth was found at 72 hours for 800 ppm and 1000 ppm of phenol as 0.999 and 1.055, respectively. it was observed that in case of 1200 ppm of phenol, only 6.45 percent phenol was removed by our isolate in 72 hours of incubation. there was no significant enhancement in cell density in medium containing 1200 ppm of phenol. in the present study, ph of the medium the removal rate of phenol at different concentration by the isolate was observed, and it is significant in the sense that phenol removal rate was directly related to increased cell growth (figure 4). a number of phenol - degrading aerobic bacteria have been described previously by other researchers [3538 ]. the concentration of phenol and presence of halogenated substrates seem to play a crucial role on degradation shown in our study and also reported by others. high concentrations of phenol are usually inhibitory to growth of organisms. compared to four isolate, pseudomonas fluorescens pu1 seems to be superior in terms of resistance or tolerance to phenol, since it could tolerate phenol up to the concentrations of 1000 ppm. hence, the present study has demonstrated that the pseudomonas fluorescens pu1 could play an important role in the remediation of phenolics in heavily polluted sites. enzyme activity was determined for the organism grown on phenol because growth substrate can influence the enzyme produced. catechol is the common intermediate in aromatic degradation and can be metabolized via either the ortho or meta cleavage pathways. the efficiency of a certain catabolic pathway often depends on the properties of the involved key enzyme(s). therefore, the specific activities of phenol hydroxylase, catechol 1,2-dioxygenase, and catechol 2,3-dioxygenase in cell - free extracts obtained by sonication from investigated isolate was examined. analysis of intercellular enzyme activity indicated that pseudomonas fluorescens pu1 showed greater metaactivity than ortho - activity which demonstrate degradation occurred using the meta cleavage pathway. specific enzyme activity carried out following growth on phenol confirmed this (table 1). catechol 2,3-dioxygenase activity towards a number of catechol was induced in cell grown on phenol. the already established, it was found that phenol degraded in both ortho and meta cleavage pathway although ortho - pathway is most common [3942 ]. assays of the key enzymes involved in the ring cleavage of catechol 1,2-dioxygenase and catechol 2,3-dioxygenase indicated that degradation of the phenol p. fluorescens pu1 was via the meta cleavage pathway. cells grown on phenol displayed greater metaactivities mainly towards catechol, while ortho - activity was very low. this suggests that p. fluorescens pu1 possesses meta cleavage enzyme, a catechol 2,3-dioxygenase capable of metabolising catechol. the aerobic phenol - degrading isolate pseudomonas fluorescens pu1 appears to have greater potential for enhanced phenol removal through utilization of phenol as sole source of carbon and energy. resistance against a high concentration of phenol facilitates its use for biological treatment system of wastewater. complete degradation of such a high concentration of phenol (1000 ppm) by metapathway is not well demonstrated previously. here we report these isolate capable of growth at relatively high phenol concentrations together with the analysis of functional properties relevant to the application of this organism to the biodegradation of aromatic wastes (phenolics). | degradation of phenolics by members of soil microflora is an important means by which these substances are removed from the environment thus reducing environmental pollution. biodegradation by microorganisms offers unique opportunities to destroy or render phenolic compounds. a bacterium, pu1, identified as pseudomonas fluorescens pu1, was investigated for its ability to grow on and degrade phenols as sole carbon sources in aerobic shaking batch culture. the organism degraded up to 1000 ppm of phenol using meta cleavage pathway. the pathways for phenol degradation were proposed by the identification of metabolites and assay of ring cleavage enzymes in cell extracts. phenol was degraded via catechol with subsequent metaring cleavage. cell growth increased as the phenol concentrations increased up to 1000 ppm phenol. the biodegradation efficiency, degradation extent, and metabolic pathway of phenol were determined to provide useful clues for further application of this isolate in the engineered bioremediation systems. the paper 's results suggest that pseudomonas fluorescens pu1 strain could be a good candidate for remediation of phenol contaminants from heavily polluted sites. |
according to traditional persian medicine (tpm) resources, the human digestive system includes four steps. in the first step, gastric digestion, the ingested food pours into the stomach and changes into the leachate called chylous due to the heat produced in the stomach. in the second step, hepatic digestion, the chylous enters in the liver through mesenteric vessels and transforms into the quadruple humors, sanguine, phlegm, bile and black bile due to the liver heat. in the case of humor predominance, using moshel or cathartic medicines is considered as a strategic medical plan. in this study, we introduce cathartic (purgative) medicines mentioned in tpm resources according to their specific function. literature review of tpm resources, including canon of medicine and aghili s makhzan - ul - adwiah was performed in order to find cathartics cited in the aforementioned books, prescribed specifically for different humor s predominance in the body. the survey found that the cathartics are categorized into eight groups : cathartic of balgham such as citrullus colocynthis and colchicum autumnalecathartic of bile such as prunus domestica and alhagi camelorum a. maurorumcathartic of sovda such as lajward stone and armenian stonecathartic of maa - e - asfar such as marrubium vulgarre and rivand extractcathartic of melancholy and phlegm such as cuscuta epithymum and adiantum capillus veneriscathartic of bile and phlegm such as nepeta menthoides and fumaria parvifloracathartic of maa - e - asfar and phlegm such as urtica dioica and qsaalhmarcathartic of all mucus such as cassia acutifolia and kharbaghe aswad cathartic of bile such as prunus domestica and alhagi camelorum a. maurorum cathartic of sovda such as lajward stone and armenian stone cathartic of maa - e - asfar such as marrubium vulgarre and rivand extract cathartic of melancholy and phlegm such as cuscuta epithymum and adiantum capillus veneris cathartic of bile and phlegm such as nepeta menthoides and fumaria parviflora cathartic of maa - e - asfar and phlegm such as urtica dioica and qsaalhmar cathartic of all mucus such as cassia acutifolia and kharbaghe aswad medical students of traditional persian medicine should be familiar with cathartics and purgatives specific for each humor. in this study, cathartics has classified into main cathartics of phlegm, bile, black bile, maa - e - asfar, black bile and phlegm, maa - e - asfar and phlegm, as well as cathartic of all triple humors for a better memorization and feasibility of prescribing in practice. | background : according to traditional persian medicine (tpm) resources, the human digestive system includes four steps. in the first step, gastric digestion, the ingested food pours into the stomach and changes into the leachate called chylous due to the heat produced in the stomach. in the second step, hepatic digestion, the chylous enters in the liver through mesenteric vessels and transforms into the quadruple humors, sanguine, phlegm, bile and black bile due to the liver heat. in the case of humor predominance, using moshel or cathartic medicines is considered as a strategic medical plan. in this study, we introduce cathartic (purgative) medicines mentioned in tpm resources according to their specific function.methods:literature review of tpm resources, including canon of medicine and aghili s makhzan - ul - adwiah was performed in order to find cathartics cited in the aforementioned books, prescribed specifically for different humor s predominance in the body.results:the survey found that the cathartics are categorized into eight groups : cathartic of balgham such as citrullus colocynthis and colchicum autumnalecathartic of bile such as prunus domestica and alhagi camelorum a. maurorumcathartic of sovda such as lajward stone and armenian stonecathartic of maa - e - asfar such as marrubium vulgarre and rivand extractcathartic of melancholy and phlegm such as cuscuta epithymum and adiantum capillus veneriscathartic of bile and phlegm such as nepeta menthoides and fumaria parvifloracathartic of maa - e - asfar and phlegm such as urtica dioica and qsaalhmarcathartic of all mucus such as cassia acutifolia and kharbaghe aswad conclusion : medical students of traditional persian medicine should be familiar with cathartics and purgatives specific for each humor. in this study, cathartics has classified into main cathartics of phlegm, bile, black bile, maa - e - asfar, black bile and phlegm, maa - e - asfar and phlegm, as well as cathartic of all triple humors for a better memorization and feasibility of prescribing in practice. |
unintentional injuries among children are the commonest cause of death and hospital admission worldwide, and can result in lifelong disability. they are a growing global public health problem and responsible for about 950 000 deaths in children under the age of 18 years each year. injuries can be prevented or controlled. in eastern mediterranean region (emr), unintentional injuries are one of the leading causes of death and disability in children. in 2004, about 12% of all global deaths due to unintentional injuries in age group under the age of 20 years occurred in emr with 113 327 cases which is about 19% higher than the world rate (45.5 vs. 38.8 per 100 000). more than 95% of these deaths occurred in low and middle income countries (lmic) of the region. the overall aims of the report are : to raise awareness about the magnitude, risk factors and impacts of child injuries in the region ; to draw attention to the preventability of child injuries and present what is known about the effectiveness of preventive interventions ; and to make recommendations that can be implemented by most of the countries in the emr to reduce child injuries effectively. this is a secondary data analysis of world report on child injury prevention focuses on most common unintentional injuries among children namely : road traffic injuries (rtis), drowning, burns, falls and poisoning, and adjusted for countries in the emr. the report used the definition of a child specified in the convention on the rights of the child, and thus focuses on injuries occurring in children under the age of 18 years. however, it has not always been possible to reflect this age cut - off in analyzing data. in some cases data could not be disaggregated to 0.05 for both main effects. the restricted model (removing the interaction term) was not adequate with the data. estimated mortality of all children 's unintentional injuries (rate per 100 000 population) by sex, and age group- eastern mediterranean region and world saturated model of table 1 - estimated mortality of all children 's unintentional injuries (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004, the mortality rate from rtis in emr was 17.4 deaths per 100 000 population under 20 years, the second highest in the world after the african region. of all the unintentional injuries among children in the region, 38.3% were from children 's rtis. this denotes 16.5% of mortality among children out of the global mortality for due to rtis with fatal outcomes. the highest rates of road traffic deaths were in the african and eastern mediterranean regions in the same year. the road traffic death rate among children globally is 10.7 versus 17.4 per 100 000 population in emr. overall, the death rate for boys is 13.8 per 100 000 population, compared to a rate of 7.5 per 100 000 population for girls. in high - income countries in emr the gender gap is greatest among young children while in the regions of europe, the western pacific and the americas the gap is more pronounced among older children. table 3 shows a comparison of estimated mortality for injuries among children due to road traffic injuries by sex, and age group in emr countries and the world. estimated mortality of all children 's road traffic injuries (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004 drowning contributed at least 18.4% of deaths among children out of all causes of unintentional injury deaths with 175 293 deaths among children under the age of 20 years worldwide. this figure in countries in the emr is 16932 (9.7% of the total global mortalities as a result of drowning). this is a conservative estimate as it does not include submersions due to floods, boating and water transport and thus the actual figure could be much higher. drowning is responsible for 14.9% of unintentional injury deaths in this age group in the em region. global drowning is the third leading cause of death due to unintentional injuries among children and youth. it is the second leading cause of deaths due to unintentional injury among the age group below 20 years age in emr. for example, in palestine territory (in 2008) it was reported to be the 3 leading cause of death and in iran (in 1998) is reported to be 2 leading cause of death from unintentional injuries in age group under 20 years (please insert reference if this is from a source other than world report). however, the death rate in the region is lower than the world rate (6.8 vs. 7.2 per 100 000). the death rate is more than twice higher among boys than girls (9.1 vs. 4.4 per 100 000). near - drowning events, in which victims survive for at least 24 hours, also result in significant numbers of injured children. it is estimated that for each drowning death, there are 1 to 4 nonfatal submersions serious enough to result in hospitalization. table 4 shows a comparison of the estimated mortality of drowning among children by sex, and age group in emr countries and the world. estimated mortality of all children 's drowning (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world table 5 shows a comparison of estimated mortality among children who died of fire - related burns by sex, and age group in emr countries and the world. worldwide 95 772 children under the age of 20 years (30% of death burns in all ages) have been fatally injured as a result of burns in 2004 alone. this figure in emr is 11079 (11.6% of global mortalities as a result of burns). burns are responsible for 9.8% of all deaths due to unintentional injury in the region. the death rate is higher among girls than boys (5.5 vs. 3.5 per 100 000). the death rate in low - income and middle - income countries of emr is 4.7 per 100 000 which is about 12 times higher than that in high - income countries. infants have the highest rates (12.1 per 100 000), while those aged between 10 and 14 years have the lowest rates (2.0 per 100 000). the death rate also shows an upward trend for age group 1 - 4 year olds (7.0 per 100 000). burns rank as 3 cause death due to unintentional injury among children in countries of the emr. outcomes of burns are costly and prolonged hospitalizations, multiple surgeries, skin grafts, risk of infection and disfigurement put tremendous economic and human cost on households and governments. estimated mortality of all children 's fire - related burns (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004, an estimated 424 000 people of all ages died from falls worldwide, with 46894 among them were children aged under the age of 20 years (4.9% of all deaths among children due to unintentional injury). this figure in emr was 7113 (15.2% of global mortalities as a result of falls). although the majority of fall - related deaths are among elders, falls do rank as the 12 and fifth leading cause of unintentional injury death among 5 to 9 year olds and 15 to 19 year olds, respectively. among children in emr falls contrary to the high prevalence of falls in high - income countries in the americas, low - income and middle - income countries in eastern mediterranean region have l a high mortality rate due to falls that is more than 14 times higher. falls is responsible for 6.3% of deaths due to unintentional injury in this age group in the region. the death rate in the region is higher than the world rate (2.9 vs. 1.9 per 100 000). it is also more among boys than girls (3.5 vs. 2.2 per 100 000). the death rate in low - income and middle - income countries of the region is slightly higher than that in high - income countries (2.9 vs. 2.2 per 100 000) compared to the global figures revealing a wide difference between these two groups of countries (2.1 vs. 0.4 per 100 000). the vast majority (97.8%) of deaths among children due to falls occur in low - income and middle - income countries of em region. the highest death rate occur in poorer areas of eastern mediterranean region (2.9 per 100 000) with 15.2% of all global deaths from falls. table 6 shows a comparative estimated mortality of deaths among children due to falls by sex, and age group in emr countries and the world. estimated mortality of all children 's falls (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004 acute poisoning resulted in over 45 000 deaths in children., 3871 children died from poisoning with the rate of 1.6 per 100 000 of fatal poisoning. the rate of fatal poisoning is highest for children under 1 year old (6.3 per 100 000). fatal poisoning rates in low - income and middle - income countries of the region are more than two times that of high - income countries (1.6 vs. 0.7 per 100 000). common poisoning agents in the region include pharmaceuticals, household cleaning agents (e.g., bleach, cleaning agents), pesticides, hydrocarbons used for fuel and lighting, poisonous plants and bites from insects / animals. poisonings do rank as the fifth leading cause of death among children under the age of 20 years due to unintentional injury in the region. the death rate is slightly more among boys than girls (1.7 vs. 1.5 per 100 000). the vast majority (97.4%) of deaths among children due to falls occur in low - income and middle - income countries in em region. table 7 shows a comparison of estimated mortality among children due to poisoning by sex, and age group in emr countries and the world. estimated mortality of all children 's poisonings (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in emr, unintentional injuries are one of the leading causes of death and disability in children. in 2004, about 12% of all global deaths due to unintentional injuries among the age group under 20 years occurred in emr with 113 327 deaths which is about 19% higher than the world rate (45.5 vs. 38.8 per 100 000). more than 95% of these deaths occurred in low and middle income countries (lmic). rate of unintentional injuries per 100 000 children in emr is 41.6 and 45.7 in high income countries (hic) and low and middle income countries (lmic) of the region respectively. rates of unintentional injuries among children for different age groups of both sexes in emr are higher than the peer rates of the world. table 1 shows estimated mortality for all unintentional injuries among children by sex, and age group in emr countries and the world. the top five leading causes of deaths due to unintentional among children under the age of 20 years from the em region are from rtis (17.4 per 100 000), drowning (6.8 per 100 000), burns (4.5 per 100 000), falls (2.9 per 100 000) and poisoning (1.6 per 100 000). the interaction term of sex and age (ij) assesses the association between the two variables. the main effect of sex (i) and age (j) tests the null hypothesis that the subjects are distributed evenly over the levels of each variable. here we have two not evenly distributed variables, thus p > 0.05 for both main effects. the restricted model (removing the interaction term) was not adequate with the data. estimated mortality of all children 's unintentional injuries (rate per 100 000 population) by sex, and age group- eastern mediterranean region and world saturated model of table 1 - estimated mortality of all children 's unintentional injuries (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004, the mortality rate from rtis in emr was 17.4 deaths per 100 000 population under 20 years, the second highest in the world after the african region. of all the unintentional injuries among children in the region, 38.3% were from children 's rtis. this denotes 16.5% of mortality among children out of the global mortality for due to rtis with fatal outcomes. the highest rates of road traffic deaths were in the african and eastern mediterranean regions in the same year. the road traffic death rate among children globally is 10.7 versus 17.4 per 100 000 population in emr. overall, the death rate for boys is 13.8 per 100 000 population, compared to a rate of 7.5 per 100 000 population for girls. in high - income countries in emr the gender gap is greatest among young children while in the regions of europe, the western pacific and the americas the gap is more pronounced among older children. table 3 shows a comparison of estimated mortality for injuries among children due to road traffic injuries by sex, and age group in emr countries and the world. estimated mortality of all children 's road traffic injuries (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004 drowning contributed at least 18.4% of deaths among children out of all causes of unintentional injury deaths with 175 293 deaths among children under the age of 20 years worldwide. this figure in countries in the emr is 16932 (9.7% of the total global mortalities as a result of drowning). this is a conservative estimate as it does not include submersions due to floods, boating and water transport and thus the actual figure could be much higher. drowning is responsible for 14.9% of unintentional injury deaths in this age group in the em region. global drowning is the third leading cause of death due to unintentional injuries among children and youth. it is the second leading cause of deaths due to unintentional injury among the age group below 20 years age in emr. for example, in palestine territory (in 2008) it was reported to be the 3 leading cause of death and in iran (in 1998) is reported to be 2 leading cause of death from unintentional injuries in age group under 20 years (please insert reference if this is from a source other than world report). however, the death rate in the region is lower than the world rate (6.8 vs. 7.2 per 100 000). the death rate is more than twice higher among boys than girls (9.1 vs. 4.4 per 100 000). near - drowning events, in which victims survive for at least 24 hours, also result in significant numbers of injured children. it is estimated that for each drowning death, there are 1 to 4 nonfatal submersions serious enough to result in hospitalization. table 4 shows a comparison of the estimated mortality of drowning among children by sex, and age group in emr countries and the world. estimated mortality of all children 's drowning (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world table 5 shows a comparison of estimated mortality among children who died of fire - related burns by sex, and age group in emr countries and the world. worldwide 95 772 children under the age of 20 years (30% of death burns in all ages) have been fatally injured as a result of burns in 2004 alone. this figure in emr is 11079 (11.6% of global mortalities as a result of burns). burns are responsible for 9.8% of all deaths due to unintentional injury in the region. the death rate is higher among girls than boys (5.5 vs. 3.5 per 100 000). the death rate in low - income and middle - income countries of emr is 4.7 per 100 000 which is about 12 times higher than that in high - income countries. infants have the highest rates (12.1 per 100 000), while those aged between 10 and 14 years have the lowest rates (2.0 per 100 000). the death rate also shows an upward trend for age group 1 - 4 year olds (7.0 per 100 000). burns rank as 3 cause death due to unintentional injury among children in countries of the emr. outcomes of burns are costly and prolonged hospitalizations, multiple surgeries, skin grafts, risk of infection and disfigurement put tremendous economic and human cost on households and governments. estimated mortality of all children 's fire - related burns (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world in 2004, an estimated 424 000 people of all ages died from falls worldwide, with 46894 among them were children aged under the age of 20 years (4.9% of all deaths among children due to unintentional injury). this figure in emr was 7113 (15.2% of global mortalities as a result of falls). although the majority of fall - related deaths are among elders, falls do rank as the 12 and fifth leading cause of unintentional injury death among 5 to 9 year olds and 15 to 19 year olds, respectively. among children in emr falls contrary to the high prevalence of falls in high - income countries in the americas, low - income and middle - income countries in eastern mediterranean region have l a high mortality rate due to falls that is more than 14 times higher. falls is responsible for 6.3% of deaths due to unintentional injury in this age group in the region. the death rate in the region is higher than the world rate (2.9 vs. 1.9 per 100 000). it is also more among boys than girls (3.5 vs. 2.2 per 100 000). the death rate in low - income and middle - income countries of the region is slightly higher than that in high - income countries (2.9 vs. 2.2 per 100 000) compared to the global figures revealing a wide difference between these two groups of countries (2.1 vs. 0.4 per 100 000). the vast majority (97.8%) of deaths among children due to the highest death rate occur in poorer areas of eastern mediterranean region (2.9 per 100 000) with 15.2% of all global deaths from falls. table 6 shows a comparative estimated mortality of deaths among children due to falls by sex, and age group in emr countries and the world. estimated mortality of all children 's falls (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world, 3871 children died from poisoning with the rate of 1.6 per 100 000 of fatal poisoning. the rate of fatal poisoning is highest for children under 1 year old (6.3 per 100 000). fatal poisoning rates in low - income and middle - income countries of the region are more than two times that of high - income countries (1.6 vs. 0.7 per 100 000). common poisoning agents in the region include pharmaceuticals, household cleaning agents (e.g., bleach, cleaning agents), pesticides, hydrocarbons used for fuel and lighting, poisonous plants and bites from insects / animals. poisonings do rank as the fifth leading cause of death among children under the age of 20 years due to unintentional injury in the region. the death rate is slightly more among boys than girls (1.7 vs. 1.5 per 100 000). the vast majority (97.4%) of deaths among children due to falls occur in low - income and middle - income countries in em region. table 7 shows a comparison of estimated mortality among children due to poisoning by sex, and age group in emr countries and the world. estimated mortality of all children 's poisonings (rate per 100 000 population) by sex, and age group - eastern mediterranean region and world unintentional injuries are one of the leading causes of death and disability in children in emr. the top five leading causes of deaths due to unintentional injury among children in emr are from rtis, drowning, burns, falls and poisoning. except for drowning and poisoning, this is the first regional report on child injuries, which is based on the secondary analysis of the world report on child injury prevention and presents the current knowledge and understanding about the five most important causes of unintentional injury among children under the age of 18 years as well as some of the actions that need to be taken in order to tackle the problem. children in poorer countries and those from poorer families in better - off countries are the most vulnerable for exposure to injury. more than 95% of deaths due to injury among children occur in such countries. approximately 40% of the deaths among those under 18 years of age in high - income countries are the result of an injury an indication of the fact that these countries, although doing better, still have a serious problem. specific concern for the lives, health and well - being of children is voiced in a series of international agreements and initiatives. most notable of these is the convention on the rights of the child, adopted in november 1989 during a session of the united nations general assembly, which affirms that each child has the right to the highest attainable level of health and the right to a safe environment. the convention requires that all appropriate legislative, administrative, social and educational measures to protect the child from all forms of physical or mental violence, injury or abuse, neglect or negligent treatment, maltreatment or exploitation, including sexual abuse are taken by countries. most countries in the world have ratified this convention, and it represents a powerful statement of their collective views on the responsibilities towards children. in addition, the fourth objective of the millennium development goals (mdg) is to reduce by two thirds the mortality of children under five years of age by the year 2015. most countries are focusing on reducing infectious diseases only in order to achieve the targets set out in the mdg 4, completing neglecting the burden of deaths caused by injuries. in many places the relative proportion of deaths as a result of injuries in this age group is significant enough to hamper the attainment of the mdg 4 if it is not addressed at the same time with the same focus. child survival has been described as the most pressing moral dilemma of the new millennium. as injuries are a leading cause of death and disability among children worldwide, efforts to prevent those injuries is particularly important for the wider issue of child survival and the improvement globally of child health. injury programmes need to be integrated into other child health strategies, with ministries of health playing a pivotal role. in addition, injuries need to be included as one of the indicators in overall child survival programmes. simply reproducing safe strategies that are relevant to adults will not protect children sufficiently. various developmental issues, risk taking behaviours, levels of activity and the child 's degree of dependence make the matter more complicated. prevention programmes that take into account these vulnerabilities and use a multidisciplinary approach have been shown to be the most effective for reducing child mortality as a result of injury. a number of countries have achieved remarkable reductions in their child injury death rates, in some cases by more than 50%. for rtis, a report in 2009 showed that emr has one of the worst road safety situations in the world with 32.2 deaths from rtis per 100 000 population and 33.3 per 10 000 vehicles. most studies in different countries of the region show rtis as a major cause of death in their countries. many countries in the region require helmet standards, child restraint laws, and apply seat belt law to all car occupants, and road safety strategy. for children 's drowning, like many other types of children 's unintentional injuries the published reports of the region are very rare. it is the second leading cause of unintentional injury death among this group in emr. a study in iran showed that drowning with 17.9% is the second cause of deaths from all children 's unintentional injuries and boys are more likely to be drowned about 1.5 times more than girls. drowning among pakistani children and among children in the united arab emirates is the second cause of deaths from unintentional injuries. effective preventive strategies have been recommended on training and equipment to reduce rollover events and on the expeditious extrication of victims. available studies suggest that people living in countries that are densely populated, with a large amount of open water are at a higher risk of drowning. other risk factors, such as gender and age, appear to be almost universal. burns are responsible for about ten percent of all unintentional injury deaths in the region. the mortality rate is higher in females and most of the burns among children occur in the home. these include the introduction and enforcement of items such as smoke alarms, residential sprinklers and fire - safe lighters, and laws regulating the temperature of hot - water taps. the risk factors depend on different mechanisms that lead to burns. some of the interventions to prevent various types of burn injuries among children are on engineering and design (such as use of safer lamps and stoves, smoke alarms, residential sprinklers), environmental measures (for instance modifying or improving construction materials ; improving heating and lighting equipment in homes ; raising cooking facilities off the ground ; separating cooking areas from living areas) ; the introduction of legislation and standards (such as laws on the temperature of hot - water taps, banning fireworks and standards for child - resistant lighters) ; and educational measures. strategies which combine legislation and standards, product modification and education appear to have the most far - reaching effects in reducing the incidence of burns. falls occur among all ages and stages of childhood accounting for 5 - 15% of all childhood injury causes. developing countries have a disproportionately high rate of fall - related injuries among children the highest rate on the asian continent has been recorded in the united arab emirates with an incidence of some 1923 per 100 000 population. children falling from stairs and windows are generally younger than those who fall from roofs, playground equipment and walls. the establishment of building code regulations for safety devices on these height sites and to mandate safer housing and playground equipment to protect these children from fall injuries and education programs for both parents and children are necessary. major reductions in the incidence of childhood fall injuries have been achieved by removing or redesigning nursery furniture, playground equipment, sports and recreational equipment, and other items such as shopping carts and wheelchairs. fatal poisoning rates in low - income and middle - income countries of the region are more than two times that of high - income countries. poisonings are the fifth leading cause of unintentional injury death among fewer than 20 year olds of the region. they are responsible for about 5% of all injury deaths in the region. in many countries the number of fatalities as a result of poisoning has been reduced over the past years, however, hospital admissions for poisonings have increased in recent years. adequate parental supervision and safe packing, storage and disposal of potentially hazardous substances could be the most important activities for prevention of childhood poisoning. furthermore, manufactures and traders must by law put certain toxic household products and drugs in child resistant containers, and mark toxic medicines with warning labels or signs. in conclusion, as injuries are a leading cause of death and disability among children of the region, injury programmes focusing of major risk factors need to be integrated into other child health strategies, with ministries of health playing a pivotal role. in addition, children 's unintentional injuries need to be included as one of the indicators in overall child survival programmes. more considerations are recommended to researchers in this region to study the scope of the problem, risk factors, interventions and evaluation of children 's unintentional injuries. | background : unintentional injuries are one of the leading causes of death and disability among children in eastern mediterranean region (emr). the issue of child injuries in the emr is a major public health concern.objectives:this study aimed to present the epidemiological pattern of children 's unintentional injuries in this region and compare the results for the emr member states and the global status based on the findings of the world report.materials and methods : this is a secondary analysis and focuses on unintentional injuries specifically road traffic injuries, drowning, burns, falls and poisoning, and adjusted for countries from emr.results:about 12% of all deaths due to unintentional injuries taking place globally under the age of 20 years took place in emr with 113 327 deaths which is about 19% higher than the world rate (45.5 vs. 38.8 per 100 000). in emr the top five leading causes of death due to childhood unintentional injuries are reported to be from road traffic injuries (17.4 per 100 000), drowning (6.8 per 100 000), burns (4.5 per 100 000), falls (2.9 per 100 000) and poisoning (1.6 per 100 000). estimated mortality showed that boys were more likely to be killed than girls. however, there was no significant difference for by age group.conclusions:injuries are the leading cause of death and disability among children in the emr and that injury programmes focusing on major risk factors need to be integrated into other child health strategies, with ministries of health playing a pivotal role. |
microscopic discectomy is a standard surgical procedure for lumbar disc herniation and has been approved as a safe method to alleviate radiating pain and other neurological symptoms. however, postoperative facet joint syndrome following microscopic discectomy is a relatively common problem requiring intervention1). the prevalence of facet joint syndrome in patients after lumbar intervention is 8 - 32 cases per 1008). the diagnosis of facet joint syndrome is confirmed when there is at least 50% relief from the targeted pain after a local anesthetic blockade of the medial branches of the posterior rami of spinal nerves that supply the facet joint3). it has been demonstrated that medial branch block and rfn are effective, but temporary, management of lumbar facet joint syndrome2,5,6,7,9,10,11,12,13,15). although the duration of relief after an initial rfn has not been established firmly, the benefits of rfn eventually dissipate in most, if not all, patients. dreyfuss.2,3) found that 60% of patients can expect 90% relief, and 87% can expect at least 60% relief from pain for about 12 months. van kleef.16) also reported successful rfn in 10 out of 15 patients. it has been recommended that when pain reappears after successful rfn, rfn may be repeated, but the outcome and duration of relief for repeated rfns after microscopic discectomy are not clearly confirmed. in this study, the experiences with repeated rfn for facet joint syndrome following microscopic discectomy have been reviewed in order to determine the success rate and duration of relief as compared to initial rfn. among 624 patients who underwent microscopic discectomy for single level disc herniation from 2005 to 2011, the medical records of patients who underwent repeated rfn for facet joint syndrome after microscopic discectomy were reviewed. we included three criteria for study entry : (1) greater than 50% reduction in the target pain after the initial rfn for at least 3 months, (2) return of pain, and (3) sufficient patient satisfaction with the initial rfn to have it repeated when pain recurred. these patients were re - evaluated by follow - up magnetic resonance image to make sure they did not have recurred or ongoing compressive lesion that were clearly indicated for microscopic discectomy. patients with previous lumbar spine surgery, compensable disability, or work injury were excluded in our study. no patient responded to intensive conservative treatments that included physical therapy, medications, and other types of spinal injections. patients who had less than 50% relief for 3 months after initial rfn or who were not satisfied with their outcome after initial rfn were excluded from our study as they were not candidates for repeated rfn. to minimize the chance of a false positive (placebo) response, medial branch block was performed twice before repeated rfn and provided relief each time. evaluation of the pain relief was done using the visual analog scale (vas). pain alleviation of more than 50% after 3 months was considered as a successful response for repeated rfn. response to each repeated rfn was compared with the initial successful rfn and graded as success (more than 50% relief from pain for 3 months) or failure (less than 50% relief from pain for 3 months). rfn was performed using a modification of the technique described by dreyfuss.2,3) on the radiolucent operative table, the patient was placed in a prone position, and the c - arm fluoroscopy was adjusted to an anteroposterior view, such that the superior and inferior margins of the vertebral body were aligned. next, in order to detect the pedicle properly, the imaging intensifier was rotated approximately 10 - 20 degrees. under x - ray inspection, an smkc10 needle (22 gauge with 5-mm active tip and 100-mm cannula) was inserted at burton 's point where the grooves made by the superior articular and transverse processes meet. on confirming the accurate location of the cannula, an electrode was inserted for electric stimulation. once we confirmed that no fasciculation occurred in the muscles of lower limbs, a lesion was made at 80 for approximately 90s. this was followed by the administration of 0.5ml of 1% lidocaine and 5 mg triamcinolone acetonide (tamcetone r, hanol inc., korea) at the end of the surgical procedure, to prevent discomfort and development of neuritis. on the radiolucent operative table, the patient was placed in a prone position, and the c - arm fluoroscopy was adjusted to an anteroposterior view, such that the superior and inferior margins of the vertebral body were aligned. next, in order to detect the pedicle properly, the imaging intensifier was rotated approximately 10 - 20 degrees. under x - ray inspection, an smkc10 needle (22 gauge with 5-mm active tip and 100-mm cannula) was inserted at burton 's point where the grooves made by the superior articular and transverse processes meet. on confirming the accurate location of the cannula once we confirmed that no fasciculation occurred in the muscles of lower limbs, a lesion was made at 80 for approximately 90s. this was followed by the administration of 0.5ml of 1% lidocaine and 5 mg triamcinolone acetonide (tamcetone r, hanol inc., korea) at the end of the surgical procedure, to prevent discomfort and development of neuritis. all patients underwent microscopic discectomy for lumbar disc herniation at l4 - 5 or l5-s1 level. secondary rfn denervated three segments (l3-l4, l4-l5, and l5-s1) bilaterally in all patients because each joint is innervated by two nerve which branch out into the posterior lumbar nerve trunks. in the 56 patients who had initial successful rfn, the repeated secondary rfns were successful in 53 (94%), but unsuccessful in three patients. the mean duration of relief in the 53 patients was 9.0 months (range 4 - 14) for the secondary rfn. there were no neurologic complications such as sensory dysesthesia and neuritis. weight bearing on the lumbar spine is distributed and supported by the anterior and posterior structures of the vertebrae. in the anterior, the facet joint, along with the ligaments, plays a main role in maintaining the stability of the posterior structures and intervertebral discs6). when discectomy is performed for the lumbar disc herniation, the disc space becomes narrow, resulting in an imbalance in the weight bearing on spinal structures, and consequently, leads to enhanced stress on the facet joint. rfn offers profound and lasting relief from back pain or buttock pain originating from the facet joint11). if patients are rigorously evaluated and accurate surgical techniques are used, more than 60% of patients can expect at least a 90% reduction in pain, and 87% can expect at least a 60% reduction lasting for about 12 months, although some may experience shorter or longer period of pain relief3,4,10,14,16). rfn does not cure facet joint syndrome, and the effects of facet denervation are not usually permanent due to nerve regeneration. benefits eventually dissipate, and rfn may need to be repeated. however, the outcome and duration of relief for repeated rfn after microscopic discectomy are not well established. in the present study, we have shown that after an initial successful lumbar rfn, repeat rfns are successful in about 94% of patients. we have chosen 50% reduction in pain relief as an indicator of success as it has been shown to correlate with a high degree of patient satisfaction16). we did not evaluate the outcomes of all patients who had an initial rfn, as this was not the purpose of the study. the sustained success after repeated rfns provided circumstantial evidence that the successful responses were true positives, at least clinically. certainly, the rfns were worthwhile in these patients. two out of three patients who showed unsuccessful result had instability at the segment at the segment where the microscopic discectomy was performed, pain relief and its duration was less. however, this is not the case with our study, since all rfns were performed by a single experienced doctor using established techniques. although transient, repeated rfns provided a mean duration of relief of 9.0 months and were successful more than 94%. nevertheless, one of the limitations of our study is that the alleviation of pain in patients can only be evaluated by subjective measures and we have not quantified changes in pain or function after rfns. the success rate was based on the patients ' satisfaction, as demonstrated by their desire to have the rfn repeated, and subjective pain relief of greater than 50%. a long - term study with more repeated rfns may be necessary for the validation of its usefulness in the management of facet joint syndrome following microscopic discectomy. this study demonstrates that, similar to primary rfn, repeated rfn can be considered as an effective palliative treatment for facet joint syndrome after microscopic discectomy. | objectivepostoperative facet joint syndrome requiring radiofrequency neurotomy (rfn) is a relatively common problem following microscopic discectomy. however, the efficacy of repeated rfn after microscopic discectomy has not been clearly documented. the purpose of this study was to determine the success rate and symptom - free duration of repeated rfn for facet joint syndrome after microscopic discectomy.methodsmedical records from 56 patients, who had undergone successful initial rfn following microscopic discectomy, experienced recurrence of pain, and subsequently had repeated rfn, were reviewed and evaluated. responses of repeated rfn were compared with initial radiofrequency neurotomy for success rates and duration of relief. the criterion for rfn to be successful was defined as greater than 50% relief from pain and sufficient satisfaction of patients with prior rfn to have repeated rfn.resultsfifty-six patients (41 women and 15 men ; mean age=48 years) had repeated rfns, which were successful in all except three patients. rfn denervated three bilateral segments (l3-l4, l4-l5, and l5-s1) in all patients. mean duration of relief after initial rfn was 9.2 months (range 3 - 14). the mean duration of relief after secondary rfn in 53 patients was 9.0 months (range 4 - 14). the success rates and duration of relief remained consistent after subsequent rfns.conclusionrepeated rfn for lumbar facet joint pain after microscopic discectomy is an effective palliative treatment. it provided a mean duration of relief of 9.0 months and > 94% success rate. |
motivational impairments are a cardinal feature of schizophrenia, are present in the earliest phases of the illness and are a significant predictor of impaired real - world functioning (foussias and remington, 2010 ; schlosser., 2014). current clinical and neuroimaging data indicate that these motivational impairments may be related to neural and behavioral deficits in anticipating future rewards (juckel., 2006 ; simon., 2010) specifically, growing evidence indicates that schizophrenia patients may not be able to use anticipation of future rewards to modulate subsequent goal - directed behavior, suggesting impairments in frontal striatal interactions and dopaminergic transmission between these regions (abi - dargham, 2003 ; barch and dowd, 2010 ; gold., 2008 ; strauss., 2015) thus, the question remains as to whether recruitment of impaired frontal striatal systems may enhance motivation and goal - directed behavior in schizophrenia patients or whether recruitment of other intact networks may be more useful targets for potentiating goal - directed functions in the real - world. the present fmri study investigates this question. the reward circuitry is well established in healthy participants (hc). abundant neuroimaging evidence indicate that, in healthy participants, the motivation to receive upcoming monetary rewards is associated with anticipatory activity in frontal striatal networks, including the medial prefrontal cortex (extending to the anterior cingulate cortex, mpfc / acc), caudate, putamen, ventral striatum and nucleus accumbens (barch and dowd, 2010 ; knutson., 2001 ; murray., specifically, data suggest that activity in the ventral striatum (vs), particularly within the nucleus accumbens, during immediate reward anticipation on a monetary incentive delay (mid) task (knutson., 2000) predicts arousal, positive affect, and, most importantly, real - world goal oriented consummatory behavior (e.g. products purchased and money spent at a shopping mall) (knutson., 2001, 2003, 2007). by contrast, when schizophrenia patients perform the mid task, several studies have consistently revealed reduced ventral striatum (vs) activity during reward anticipation (juckel., 2006 ; kirsch., 2007 prior behavioral research indicate that while patients with schizophrenia reveal specific deficits in anticipating signals leading to future rewarding outcomes, they experience similar levels of consummatory (in the moment) pleasure to hc participants (gard., 2007 ; herbener., however, it must also be noted that not all studies have found trait differences between schizophrenia and hc participants in self - reported anticipatory pleasure ratings (assayed with the teps anticipatory scale) (strauss., 2011) ; indeed some behavioral studies have shown that deficits in schizophrenia patients ' ability to respond to future rewarding stimuli occur only when the stimuli are not presently available compared to when the rewarding cues are more immediately present (heerey., 2011). together, these findings suggest that additional studies are needed that use anticipatory pleasure ratings from the teps anticipatory scale with neuroimaging measures of immediate reward anticipation, to determine the precise neural underpinnings of amotivation in schizophrenia. to this end, the purpose of this study is to use fmri in schizophrenia to explicitly examine the relationship between neural activity during the anticipation of an immediate reward (assayed when participants anticipate winning money in response to a win $ cue) in relation to self - reports of real world motivated behavior (both in - the - moment pleasure as represented by the teps consummatory scale, and future representations of pleasure, as measured by the teps anticipatory scale). therefore, it is possible that neural activation patterns during current representation of rewarding cues in schizophrenia may not directly be associated with future representations of reward (measured with the teps - anticipatory scale), but rather with more intact consummatory pleasure levels (assayed here with the teps - consummatory scale), as is shown in healthy participants (knutson., 2007). it also must be noted that while the process of anticipating pleasure can enhance motivation and preparation for upcoming future rewarding events, high levels of consummatory (in the moment) pleasure can also increase neural reward motivational processes to repeat a rewarding activity (trmeau., 2010). in the present study, we therefore hypothesized that it was possible for neural signal during immediate reward anticipation on the mid task to be correlated with either the teps - anticipatory scale, the teps - consummatory scale or with both scales. since deficits in anticipatory pleasure are related to deficits in motivation and functional outcome (gard., 2007), and since amotivation in schizophrenia has been shown to be a central predictor of poor functioning, these findings suggest that deficits in anticipating pleasure can contribute to functional disability in schizophrenia (foussias and remington, 2010 ; gard., 2009). however, thus far, no one has investigated the explicit link between deficits during anticipation of immediate rewards, real world motivated behavior (both in - the - moment and the future), and real - world functioning, and whether and how additional intact neural networks (rather than impaired frontal striatal circuits) may mediate motivated behavior in schizophrenia. to this end, we examined whole - brain activation in sz patients and hc participants during the anticipatory phase of presentation of stimuli that predicted immediate monetary gain (reward) and loss (punishment), as well as during the outcome phase when participants were notified as to whether they had won money or lost money (knutson., 2000). previous research has shown that activation within the ventral striatum during anticipation of an immediate reward is negatively correlated with negative symptoms, such as apathy (i.e., lack of motivation), as well as with positive symptoms, while striatal activation during reward outcome is negatively correlated with depressive symptoms (juckel., 2006 these findings suggest that lower striatal activation during anticipation of an immediate reward may contribute to patients ' lack of motivation as well as to the development of psychotic symptoms while lower striatal activation during reward outcome may contribute to depressive symptoms (simon., 2010). in the present study, we examine whole - brain neural activation in relation to clinical symptoms (assayed with the positive and negative symptom scale), motivation (assayed with the behavioral activation scale) ; both anticipatory pleasure ratings of future representations of reward and in the moment consummatory pleasure ratings (assayed with the teps) (gard., 2007) and with real - world functional capacity (ucsd performance - based skills assessment) (patterson., given that prior meta - analyses have indicated that sz patients do not reveal deficits during in the moment emotional experiences (cohen and minor, 2010), we predicted that we would not observe overall group differences in neural activation when sz patients were notified that they had won money. however, in view of the previous studies mentioned above, we hypothesized that sz patients would reveal hypoactivation in vs specifically during immediate reward anticipation. to our knowledge, this is the first study to investigate whether frontal striatal dysregulation during immediate reward anticipation may require recruitment of additional intact networks such as those within parietal regions in schizophrenia, that may predict better motivation (assayed with bas - drive scale), consummatory pleasure (teps) and real - world functioning (assayed with the ucsd performance - based skills assessment). this study represents the baseline imaging data from the imaging component of our nimh - funded ro1 of a double - blind randomized clinical trial of cognitive training in schizophrenia (clinicaltrials.gov nct02105779). thirty - seven clinically stable volunteer schizophrenia patients (sz : mean age = 45.14 ; mean education = 14.55 years ; mean iq = 102.11 ; mean illness duration = 25.40 years), who were willing to undergo two imaging sessions, were recruited from the parent study. all patients were stratified by age, education, gender, and symptom severity and then randomly assigned to either social computerized cognitive training, or to a control computerized cognitive training condition without the social training, performed for 80 h. informed consent was obtained from all subjects. schizophrenia patients were scanned using fmri while they performed the monetary incentive delay task (used to assay reward / punishment processing) at baseline and after 80 h of intervention. we report here the results at baseline of our reward / punishment fmri experiment investigating frontal striatal cortical systems in schizophrenia patients when compared to 20 healthy comparison participants (hc), matched at a group level on age, gender, and education (table 1). fmri data from two sz participants were later excluded due to very poor signal to noise ratio, resulting from excessive motion during the scan. eligibility diagnosis for schizophrenia was determined using the structured interview for the dsm (scid) (first., 2002). symptom severity in schizophrenia was assessed with the positive and negative syndrome scale (panss) (kay., 1987). neurocognition was assessed using the matrics consensus cognitive battery (mccb, nuechterlein., 2008) which assesses seven cognitive domains : attention / vigilance, speed of processing, working memory, verbal learning, visual learning, reasoning and problem solving, and social cognition, and provides a global cognition score across all measures. associations were conducted between reward anticipation and the mccb measures of global cognition and reasoning and problem solving (neuropsychological assessment battery mazes test). recent research indicate that neurocognitive function predicts real - world functional outcome in patients with schizophrenia but this is largely mediated by functional capacity (e.g. the ability to perform functionally relevant, everyday living skills such as writing a check, following a bus schedule), as measured with the ucsd performance - based skills assessment (upsa) (bowie., 2006). therefore, we thought that the upsa would be the most valid and reliable measure to assess functional capacity in schizophrenia, related to the skills essential to the individual 's ability to function independently in the community (patterson., 2001). the behavioral inhibition and behavioral activation scales (bis / bas), which are a self - report measure of reward sensitivity, were used to assess aversive and appetitive motivation in schizophrenia (carver and white, 1994). i worry about making mistakes and when i want something, i usually go all - out to get it. the temporal experience of pleasure scale (teps) was used to measure individual dispositions in reward responsivity during real - world experiences of future anticipatory pleasure and in - the - moment consummatory pleasure (gard., 2007). examples of anticipatory pleasure items include : looking forward to a pleasurable experience is in itself pleasurable and consummatory pleasure items include : a hot cup of coffee or tea on a cold morning is very satisfying to me. the scid, panss, upsa, and bis / bas were administered only to sz patients. the teps was administered to both hc and sz participants on the day of scanning. we used a standard monetary incentive delay (mid) task, as described by knutson. (2001), to assay the neural patterns associated with immediate anticipation and outcome of monetary reward (gain) and punishment (loss) in sz and hc participants (knutson., 2001). the mid paradigm is a reaction time (rt) task in which each trial has a pre - established monetary value. at the beginning of each trial, a cue (i.e., marking the onset of an anticipatory period) indicates the amount of money at stake on that trial : win cues indicate potential monetary gain, null cues indicate no monetary gain / no outcome, and lose cues indicate potential monetary loss (fig. when the cue is presented, participants anticipate making a speeded response to the target (a white square), which is presented on the screen after a variable fixation interval (i.e., the anticipation period, duration from 2, 4, 6 or 8 s, randomized across all trials). such variable delays were used to jitter the events and optimize deconvolution of the fmri signal from successive events. after participants respond to the target, they receive feedback on how they performed on that trial in terms of receiving rewarding, punishing or neutral feedback. specifically, on win trials, participants are informed as to whether or not they won money ; on null trials, participants receive neutral feedback that they did not win / lose money ; and on lose trials, participants are informed as to whether or not they lost money on that trial. after the feedback prompt, there is a variable inter - trial - interval (iti), jittered between 2, 4, 6, or 8 s randomized across all trials, after which the next cue is presented (marking the onset of the next anticipatory period). for example, for each participant, performance level was titrated at 68% accuracy, such that the response window determining success was based on the participant 's mean rt within one standard deviation of the mean averaged across performance based on the previous run. responses to the first run were roughly titrated at 68% accuracy based on a previous practice run. responses to the white square were captured for the total target presentation duration (i.e., 0.5 s) ; however, participants were specifically instructed to respond as fast as possible as soon as the target appeared. early responses prior to target onset were not considered and participants were instructed not to make multiple responses. each run consisted of 60 trials : 20 win trials, 20 null trials and 20 loss trials, pseudorandomized. participants completed 3 runs altogether, with each run lasting for a total time of 12 min and 24 s. participants were provided with money based on their maximum earnings on their best performance run. overall accuracy for each participant was calculated by computing the total number of win trials and no - loss trials, averaged across the three runs. immediately after the fmri scan, participants rated their affect and arousal retrospectively on how they had felt when they viewed each condition on the mid task (i.e., win, lose, null). affect was rated on a likert scale of 17, labeled on each end from negative to positive, and arousal was similarly rated on a likert scale of 17, labeled on each end from not aroused to very aroused. was defined as feeling activated, charged or energized, physically or mentally. we first conducted between - group one - way anovas in spss to examine between - group differences for overall accuracy (only correct trials) and rt (for both correct and incorrect trials) (fig. we next conducted between - group 2 2 repeated - measures anova on accuracy to examine the main effects of condition (win / no - lose accuracy), main effects of group (hc / sz), and group by condition (win / no - lose) interaction effects. we also conducted between - group 2 3 repeated - measures anova on overall rt to examine the main effects of condition (win / no - lose / null rt), main effects of group (hc / sz), and group by condition (i.e., win / no - lose / null) interaction effects. visual stimuli were presented with matlab and back - projected onto an lcd projector. participants viewed the screen using a mirror attached to the head coil and made finger - press responses on a fiber - optic response pad. fmri was acquired on a 3 tesla tim trio siemens scanner and twelve channel head coil, using an echo - planar sequence (tr = 2.4 s, 35 slices, 306 volumes, te = 30 ms, fov = 230 mm ; matrix = 64 64). slice timing was performed in interleaved order, where the first slice was used as the reference. images were realigned to correct for motion artifacts using a 6-parameter affine transformation, normalized to a standard stereotaxic space (montreal neurological institute template) using a 12 parameter affine / non - linear transformation, and spatially smoothed with an 8 mm full - width half - maximum (fwhm) gaussian kernel. data were submitted to a general linear model analysis. for each participant (i.e., first - level analysis), we fit a reference canonical hemodynamic response function (hrf) to each event within the trial (i.e., cue, the fixation period between cue and target, target, and feedback) (see fig. we then computed the following contrasts of interest:(i)for immediate reward anticipation, we contrasted signal during the anticipation to win money with no outcome trials (i.e., win cue plus fixation vs. null cue plus fixation) by modeling the entire anticipatory period of the cue and fixation - cross presentation duration;(ii)for immediate punishment anticipation, we contrasted signal during the anticipation to lose money with no outcome trials (i.e., lose cue plus fixation vs. null cue plus fixation), by modeling the anticipatory period of the cue and fixation - cross presentation duration(iii)for reward outcome, we contrasted signal when participants were notified that they won money (monetary gain) compared to when they did not win money on win trials, by modeling the duration of the feedback prompt(iv)for punishment outcome, we contrasted fmri signal when participants were notified that they lost money (monetary loss) compared to not losing money on lose trials by modeling the duration of the feedback prompt. for immediate reward anticipation, we contrasted signal during the anticipation to win money with no outcome trials (i.e., win cue plus fixation vs. null cue plus fixation) by modeling the entire anticipatory period of the cue and fixation - cross presentation duration ; for immediate punishment anticipation, we contrasted signal during the anticipation to lose money with no outcome trials (i.e., lose cue plus fixation vs. null cue plus fixation), by modeling the anticipatory period of the cue and fixation - cross presentation duration for reward outcome, we contrasted signal when participants were notified that they won money (monetary gain) compared to when they did not win money on win trials, by modeling the duration of the feedback prompt for punishment outcome, we contrasted fmri signal when participants were notified that they lost money (monetary loss) compared to not losing money on lose trials by modeling the duration of the feedback prompt. we isolated activation during immediate reward / punishment anticipation by comparing brain activation for each participant during the win / lose cue with the null cue. during both null cue and win cue, participants anticipate making a response (i.e., pressing a button to a target). therefore, the only cognitive process that is different (and, consequently, results in brain activation differences) during the win cue versus null cue has to be specifically due to anticipation of a reward, rather than due to a preparatory motor response (pressing a button to a target). our general linear model (glm) analysis allowed us to extract signal to each trial - type, and to factor out signal due to temporally adjacent events (e.g. to the feedback response), to ensure that signal could be isolated to the event of interest (e.g. reward anticipation). for example, when extracting signal related to anticipation events, we included in the analysis : the target and the feedback responses to factor out signal tied to those outcome events than to the anticipation event. next, we conducted one sample t - tests to investigate random - effects whole - brain voxelwise analyses for each group for each contrast using a significance threshold of p.20). however, interestingly, we found distinct differences between the hc and sz groups in terms of their neural signal association with the teps consummatory pleasure scale. specifically, the hc group revealed neural activity in four regions during reward anticipation that predicted higher self - ratings of teps consummatory pleasure ; this association was found in : left putamen (r =.53, df = 18, p =.02), vs (r =.48, df = 18, p =.03), mpfc (r =.45, df = 18, p =.04), and right putamen (r =.44, df = 18, p =.05). in contrast, the sz group revealed signal increase in only one region, the right ipl, that predicted higher self - ratings in teps consummatory pleasure (r =.35, df = 33, p =.04) (fig. 4). signal in right ipl was also associated with higher self - ratings on bas - drive (r =.39, df = 33, p =.02) while signal in the left ipl predicted better real - world functional capacity, as measured by the upsa (r =.34, df = 33, p =.05). finally, whole - brain regression analyses provide additional confirmatory evidence that teps anticipatory pleasure, teps consummatory pleasure and bas - drive predicted r. ipl signal during immediate reward anticipation in schizophrenia patients (see supplementary fig. although, fisher r - to - z transformations did not reveal any significant between - group difference in the strength of the association between r. ipl and teps consummatory pleasure (z =.58, p =.28), we did find a significant between - group difference in the relation between teps consummatory pleasure and ventral striatum (z = 1.91, p =.03), left putamen (z = 2.57, p =.005), as well as mpfc (z = 2.57, p =.005). together, these findings suggest that sz and hc participants show significantly different associations between frontal striatal activation during anticipation of immediate rewards, and self - ratings of real - world reward responsivity. overall, symptom ratings were low in this clinically stable group of sz participants (average rating slightly over 2, mild). however, we did find a positive correlation between positive symptom severity with mean beta signal in mpfc (r =.33, df = 33, p =.05) and mid - cingulate (r =.37, df = 33, p =.03) during immediate reward anticipation. this positive relationship between mid - cingulate signal with positive symptoms was also confirmed by our whole - brain voxel - wise regression analyses in which positive symptom severity predicted activation in the mid - cingulate region during reward anticipation (see supplementary fig. 2). there was no association between mean beta signal in any of the rois during reward anticipation with either problem - solving or global cognition (all p values > 0.10). whole - brain conjunction analyses revealed that the two groups activated the same network, with activation overlap observed within bilateral putamen and l.ipl (fig. 5). additionally, further roi analyses revealed that signal in none of the three rois correlated with any clinical / neuropsychological measures (all ps >.10). whole - brain conjunction analyses revealed similar qualitative activation patterns between hc and sz participants during anticipation of immediate punishments versus the null condition. specifically, schizophrenia patients recruited the same regions that healthy participants activated (i.e., mid - cingulate, bilateral putamen and occipital regions), although functional overlap was only observed within the left occipital region (fig. 6). further roi analyses indicated that the left occipital region did not correlate with any clinical / neuropsychological measures (all ps >.20). whole - brain 1-sample t - tests in the combined cohort revealed that only one region, the medial superior frontal gyrus (extending to the anterior cingulate cortex, msfg / acc), showed increased activation during the outcome phase when participants were notified that they had lost money compared to no monetary loss (fig. interestingly, roi analyses indicated that the msfg / acc was also the only region in which between - group quantitative differences in signal were found. specifically, sz participants revealed significantly reduced activation during monetary loss versus no loss when compared to hc participants (f = 4.69, df = 1,53 p =.035) (table 4). we conducted an fmri study investigating neural activation patterns in schizophrenia during immediate prediction and outcome of rewards and punishments on the mid task, and investigated how neural signal related to measures of real - world reward sensitivity, responsivity, and functional outcome. we found that:1)sz patients showed impaired accuracy on both win (reward) and lose (punishment) conditions when compared to hc participants. although accuracy was titrated for each participant at roughly 68% based on the previous run, we still observed group differences in accuracy. these findings suggest that hc participants performed better than sz participants with each subsequent run. additionally, although sz participants were slower than hc participants on each condition, they showed the same accuracy and rt patterns as the hc group in that both groups had higher accuracy scores on the win compared to lose conditions, and both groups also had the slowest rt on the null condition and fastest rt on the win condition. further, one - way between - group anovas did not yield any brain regions in which sz patients showed increased activation to neutral stimuli when compared to hc participants, confirming that the current findings can not be explained by aberrant salience to neutral stimuli compared to motivationally salient information (esslinger., 2012).2)during immediate reward anticipation, both hc and sz participants showed increased activation in several regions, including : vs, bilateral putamen, bilateral ipl, mpfc, mid - cingulate and occipital areas. hc participants showed a significant relationship between reward - mediating regions (i.e., vs, mpfc, bilateral putamen) and self - ratings of teps consummatory pleasure, whereas sz participants showed a significant association between right ipl and self - ratings of teps consummatory pleasure.3)during punishment outcome, sz patients revealed hypoactivation in the msfg when compared with hc participants. sz patients showed impaired accuracy on both win (reward) and lose (punishment) conditions when compared to hc participants. although accuracy was titrated for each participant at roughly 68% based on the previous run, we still observed group differences in accuracy. these findings suggest that hc participants performed better than sz participants with each subsequent run. additionally, although sz participants were slower than hc participants on each condition, they showed the same accuracy and rt patterns as the hc group in that both groups had higher accuracy scores on the win compared to lose conditions, and both groups also had the slowest rt on the null condition and fastest rt on the win condition. further, one - way between - group anovas did not yield any brain regions in which sz patients showed increased activation to neutral stimuli when compared to hc participants, confirming that the current findings can not be explained by aberrant salience to neutral stimuli compared to motivationally salient information (esslinger., 2012). during immediate reward anticipation, both hc and sz participants showed increased activation in several regions, including : vs, bilateral putamen, bilateral ipl, mpfc, mid - cingulate and occipital areas. hc participants showed a significant relationship between reward - mediating regions (i.e., vs, mpfc, bilateral putamen) and self - ratings of teps consummatory pleasure, whereas sz participants showed a significant association between right ipl and self - ratings of teps consummatory pleasure. during punishment outcome, sz patients revealed hypoactivation in the msfg when compared with hc participants. our whole - brain analyses indicate that as subjects anticipated immediate monetary rewards, several regions revealed increased activation, including vs, bilateral putamen, bilateral ipl, mpfc and mid - cingulate, in our combined cohort of hc and sz participants. further, whole - brain conjunction analyses revealed all regions that showed activated voxels that were common to both hc and sz groups, suggesting similar whole - brain qualitative patterns of neural activity in the 2 groups. interestingly, whole - brain regression analyses revealed that anticipatory representations of future reward (assayed with teps anticipatory pleasure scale) as well as consummatory pleasure ratings (assayed with the teps consummatory pleasure scale) predicted signal in only one region, the right ipl, in sz patients during immediate reward anticipation (i.e., during the win cue). it has also been previously shown that remembered consummatory pleasure is a critical predictor of motivation in schizophrenia (trmeau., 2010), which seem to be supported with the findings in our current neuroimaging study. our roi analyses indicated that in sz patients, compared with hc participants, the vs showed reduced activation during immediate reward anticipation, and the medial sfg showed reduced activation during punishment outcome. the medial sfg / acc region has been implicated in conflict monitoring and error detection (alain., 2002 ; garavan., 2003 ; gehring and knight, 2000). thus, it may be possible that hc participants recruit the msfg to a greater extent during error - monitoring, which, in turn, likely contributes to better subsequent performance during punishment trials and, consequently, may help them perform better at avoiding monetary loss in the future, when compared to sz participants. given past research showing that striatal activation is associated with reward anticipation and that sz patients reveal lower striatum signal during anticipation of immediate upcoming rewards (juckel., 2006), the present findings corroborate prior research confirming that although sz patients do show similar whole - brain neural activation patterns to hc participants, they do exhibit reduced striatal activation during anticipation of immediate rewards. our findings also revealed that during immediate reward anticipation, sz patients showed a positive association between mpfc and mid - cingulate signal with positive symptom severity. while some prior studies have shown an inverse relationship between reward - related activation with positive symptoms (schlagenhauf., 2009), other studies have shown positive associations between frontal and striatal signals with positive symptom severity (rotarska - jagiela. temporal connectivity positively correlated with positive symptom severity in schizophrenia, which suggests that psychopathology may be associated with intrinsic frontal aberrations. temporal regions with positive symptoms (such as hallucinations) is that there is impaired connectivity between frontal areas (involved in anticipatory processing for an upcoming action) and temporal areas (involved in auditory perception) in which hallucinations are thought to result from misinterpreted speech intentions (rotarska - jagiela., in other words, frontal regions (such as the mid - cingulate) may be activated during prediction errors between anticipatory speech intentions and outcome. similarly, in our study, one speculation is that the mid - cingulate may also be activated during prediction errors between immediate reward anticipation and outcome, in which mid - cingulate signal correlates with positive symptom severity. in our clinically stable sample of patients, since most of our patients were on atypical antipsychotic medications, we do not believe that these findings are due to effects of dopaminergic - blocking typical versus atypical medications (juckel. furthermore, we did not find any regions in the brain where cpz medication dosage predicted reward anticipatory / outcome activation in our whole - brain regression analyses. striatal circuitry during immediate reward anticipation are inherent to the illness even in our low - symptom clinically stable sample of schizophrenia patients. the present paper also extends prior research in that sz and hc participants showed different responses in their brain behavior associations with self - ratings of reward responsivity (i.e., teps consummatory pleasure ratings). hc participants revealed associations in bilateral putamen, mpfc and vs with hedonic consummatory pleasure ratings while sz participants revealed correlations with consummatory pleasure ratings within the right ipl. it must also be noted that we did not find significant activation group differences within the ipl or a significant between - group difference in the strength of the association between r. ipl and reward responsivity. however, we did find a significant between - group difference in the strength of the relation between reward responsivity, and left putamen, vs and mpfc. we think that we did not observe a significant between - group difference in r. ipl because the slopes are in the same direction for both groups (unlike the slopes within mpfc, vs and left putamen in which we do find a significant between group difference). these findings hint at the possibility that both hc and sz groups may benefit from enhanced ipl signal during immediate reward anticipation (although the association with reward responsivity seems to be stronger in the sz than that in the hc group). together, these findings suggest that sz and hc participants show significantly distinct associations between frontal striatal activation during anticipation of reward, and self - ratings of real - world reward responsivity. consistent with prior studies, our findings indicate that sz patients did not differ from hc participants in the level of their consummatory pleasure ratings (gard., 2007) but only in terms of the brain regions that predicted consummatory pleasure. furthermore, sz patients did not differ from hc participants in their positive affect and arousal ratings to the rewarding cue. these findings suggest that patients ' experience of positive affect and arousal in response to immediate rewarding stimuli is intact, in agreement with previous literature (cohen and minor, 2010 ; llerena., 2012), but point towards distinct differences between reward - related anticipatory neural activity and the reported subjective experience of pleasure. specifically, while healthy participants recruited regions known to mediate reward - anticipatory activity such as the basal ganglia (bilateral putamen) and vs (barch and dowd, 2010 ; knutson., 2001 ; nielsen., 2012) that predicted trait hedonic pleasure, sz patients revealed right ipl activation a region that is not considered central to reward processing (singh - curry and husain, 2009). during anticipation of immediate rewards, the right ipl was also correlated with overall motivational drive (i.e., bas - drive) to move towards a desired goal in sz participants, while the left ipl predicted better functional capacity (as measured by the upsa). together, these findings indicate that the signal in the ipl (rather than reward - mediating regions) predicts enhanced functional capacity in individuals with schizophrenia. finally, our findings suggest that activating impaired frontal circuits during the reward anticipatory phase may not be beneficial for clinical symptoms in our sample of chronically - ill albeit clinically stable sample of sz participants, but point towards recruitment of more intact systems within the ipl that are likely to predict enhanced motivation and functional capacity. although the ipl is involved in multiple cognitive and emotional processes, it is particularly important for attention during saliency processing and consequently, facilitates goal - directed activities. salient information activates both the right and left ipl ; however, the right ipl is thought to be more involved in directing attention to salient relevant information, while the left ipl is activated particularly during suppression of irrelevant information (mevorach., 2006). thus, both right and left ipl support attention to salient information that is needed for goal - directed functional capacity. this is consistent with findings from other studies that indicate that the parietal cortex is modulated when participants engage in increased attentional effort across a broad range of cognitive tasks (kanwisher and wojciulik, 2000 ; shuman and kanwisher, 2004). furthermore, damage to the ipl has been reliably associated with hemi - spatial attentional neglect (mesulam, 1999), in which patients fail to attend to information in their left visual field, indicating that ipl is necessary for attention processes. 2005) have specifically shown that ipl is modulated by changes in attentional cues that mediate motivational salience on their monetary incentive task, and ipl signal is enhanced when motivationally salient information (i.e., rewarding cues) is combined with transcranial magnetic stimulation (tms) on the mid task (stanford., 2013). together, these findings suggest that in sz participants, enhanced ipl activity during immediate reward anticipation and its association with bas - drive supports enhanced attention to incoming salient information, which then increases patients ' motivation to move towards a desired goal, thus, contributing to enhanced functional capacity (as shown by ipl signal association with the upsa scale). indeed, gard. (2009) also conducted path analyses to find that motivation plays a mediating role between neurocognition and functional outcome. these findings corroborate prior research, suggesting that the ipl may have a functional attention - mediating compensatory role during reward motivation in psychiatric disorders such as schizophrenia (stanford., 2013). the present findings indicate that sz patients showed reduced accuracy on reward and punishment trials when compared to hc participants. however, both hc and sz participants showed a similar accuracy and rt pattern, being most accurate and fastest on the win condition and slowest on the null condition. therefore, we do not believe that the current findings can be explained by sz participants showing reduced willingness to expend effort in order to achieve monetary rewards. the results point to common whole - brain qualitative activation patterns during immediate reward and punishment anticipation and outcome in the two groups, as well as quantitative between - group differences (with sz patients showing hypoactivation in ventral striatum) during immediate reward anticipation. finally, whereas hc participants activated reward - related circuits in vs, bilateral putamen and mpfc during immediate reward anticipation, which predicted hedonic pleasure, sz participants activated regions such as the ipl (mediating attention rather than reward mechanisms) that predicted hedonic pleasure and functional capacity. together, these findings suggest that the study and treatment of motivation deficits in patients with schizophrenia may require a more detailed investigation of the role of the ipl as a circuit modulator during immediate reward anticipation that may contribute to real - world functioning capacity. | amotivation in schizophrenia is a central predictor of poor functioning, and is thought to occur due to deficits in anticipating future rewards, suggesting that impairments in anticipating pleasure can contribute to functional disability in schizophrenia. in healthy comparison (hc) participants, reward anticipation is associated with activity in frontal striatal networks. by contrast, schizophrenia (sz) participants show hypoactivation within these frontal striatal networks during this motivated anticipatory brain state. here, we examined neural activation in sz and hc participants during the anticipatory phase of stimuli that predicted immediate upcoming reward and punishment, and during the feedback / outcome phase, in relation to trait measures of hedonic pleasure and real - world functional capacity. sz patients showed hypoactivation in ventral striatum during reward anticipation. additionally, we found distinct differences between hc and sz groups in their association between reward - related immediate anticipatory neural activity and their reported experience of pleasure. hc participants recruited reward - related regions in striatum that significantly correlated with subjective consummatory pleasure, while sz patients revealed activation in attention - related regions, such as the ipl, which correlated with consummatory pleasure and functional capacity. these findings may suggest that sz patients activate compensatory attention processes during anticipation of immediate upcoming rewards, which likely contribute to their functional capacity in daily life. |
obesity is nearly twice as prevalent among people with serious mental illness, including schizophrenia spectrum and mood disorders, compared to the general population. the combination of poor diet, sedentary lifestyle, metabolic effects of psychiatric medications, poverty, and elevated obesity rates have devastating consequences on the cardiovascular health of people with serious mental illness and contribute to the dramatically shortened life expectancy impacting this group. there are over 1.5 billion active facebook users worldwide, and recent studies have found that even people with serious mental illness are increasingly using popular social media platforms. therefore, the wide reach and popularity of facebook may afford highly scalable and low - cost opportunities for engaging individuals with serious mental illness in lifestyle interventions aimed at addressing elevated rates of obesity and promoting positive lifestyle habits. in the general population several studies have demonstrated the feasibility and acceptability of using facebook for behavioral weight loss, and the effectiveness of a facebook group for promoting weight loss when used in combination with supportive text messaging. a recent review also found that online social networking platforms including facebook could effectively support interventions targeting modifiable health behaviors such as physical activity and diet. among people with serious mental illness, recent review articles have demonstrated that online social networking platforms are feasible for reaching these individuals and delivering interventions targeting depression and mental health symptoms. however, the feasibility and acceptability of using facebook to support lifestyle interventions aimed at promoting healthy eating and exercise in this group has not been explored. recent randomized controlled trials have demonstrated that people with serious mental illness enrolled in behavioral weight loss programs can successfully achieve modest weight loss. however, research shows that among people with serious mental illness, many of the poor lifestyle habits such as unhealthy eating and sedentary behaviors are largely influenced by their social surroundings. as facebook becomes an important part of the social environments of many people with serious mental illness, it may serve as a platform for extending health promotion efforts beyond clinical or professional settings, and to reach these individuals in new ways. for participants enrolled in group - based weight loss programs, therefore, facebook could also provide more opportunities for participants with serious mental illness who are already enrolled in a group - based lifestyle intervention to interact and to support each other outside of formal face - to - face sessions. using facebook to extend support and encouragement may be especially valuable for people with serious mental illness who face additional challenges to adopting healthier lifestyle behaviors, such as the impact of symptoms on motivation, effects of social isolation, or societal stigma associated with having a mental illness. the objective of this pilot study was to explore the feasibility and acceptability of using facebook to support a group - based lifestyle intervention targeting healthy eating and exercise among obese adults with serious mental illness. we employed a mixed methods design, where participants completed post - intervention feasibility and acceptability questionnaires about their use of facebook, followed by in - depth qualitative interviews to expand on their responses and to obtain detailed feedback to inform the future use of facebook for targeting weight loss in this group. participants enrolled in a six - month group lifestyle intervention were invited to join a facebook group created specifically for the program. from july to october 2014, we recruited a convenience sample of individuals with serious mental illness from a community mental health center to participate in a lifestyle intervention. clinical staff at the mental health center recommended interested and eligible participants for enrollment in the program. eligible participants were 21 years of age or older ; had a serious mental illness defined by an axis i diagnosis of schizophrenia, schizoaffective disorder, major depressive disorder, or bipolar disorder (based on the structured clinical interview for dsm - iv and confirmed by clinicians at the community mental health center) ; and had obesity defined as body mass index 30 kg / m. participants were also on stable pharmacological treatment defined as receiving the same psychiatric medications over the past two months. participants were excluded if they were residing in a nursing home or other institution, had cognitive impairment defined as a mini mental status exam score < 24, had an active substance use disorder, or were unable to speak english. we provided participants with smartphones to access facebook through a mobile application for the study duration. participants completed baseline assessments as well as post - intervention assessments and interviews, and were compensated $ 20 to cover their time for completing the assessments and $ 20 for completing the interviews. participants were not compensated for enrolling in the study, participating in the lifestyle intervention, or joining the facebook group. committees for the protection of human subjects at dartmouth college and the new hampshire department of health and human services approved all study procedures. the lifestyle intervention was adapted from the evidence- based diabetes prevention program and was delivered through an urban community mental health center in new hampshire. the modified program focused on achieving weight loss through healthy eating and exercise and consisted of 24 weekly sessions, twice weekly optional exercise classes led by a certified fitness trainer and tailored to the needs and abilities of sedentary adults, and mobile health technology support including a private facebook group, text message reminders, and wearable devices for tracking steps. the standard diabetes prevention program curriculum consists of 16 weekly sessions, but this was expanded to six months (24 weekly sessions) to incorporate additional content aimed at addressing the impact of mental health symptoms on the ability to make positive health behavior changes. research suggests that shorter lifestyle interventions may not be as effective as longer and more intensive interventions for supporting behavioral weight loss among high - risk groups of individuals with serious mental illness. participants were taught standard weight - loss techniques such as goal setting, self - monitoring dietary intake and physical activity, and problem - solving to overcome challenges to engaging in exercise or preparing healthy meals on a fixed budget. two graduate students with certification as lifestyle coaches for delivering the official diabetes prevention program content taught the weekly sessions. the life - style coaches received weekly supervision from study staff for the duration of the project. we created a private facebook group for the program. within the group, only participants whom we invited could post or share content such as text, photos, or videos, view posts, click like to show that they enjoyed a post, or post comments visible only to other group members. we introduced the facebook group and the ground rules for its use to participants in the sixth session of the 24-session lifestyle program. the lifestyle coaches and a member of the research staff provided a 30-minute briefing to participants for using the facebook group. participants used the private facebook group for a total of 20 weeks (including one holiday week with no group session). participants were instructed to only post content related to healthy eating and exercise, that was supportive and encouraging, and that described successes or challenges towards achieving healthy lifestyle goals. participants were asked not to post personally identifying information such as address or phone number, photos of other people without their permission, photos of children, grandchildren or other family members, or any hurtful or rude comments. we explained that the facebook group was intended to reinforce content from the weekly group sessions and to allow participants to interact and share personal successes and challenges with meeting weight loss and physical activity goals outside regular meetings. study staff also posted content related to topics covered in the group sessions, reminders to exercise, and tips for healthy eating. for participants who were new to facebook, we helped them set up an account, and provided instruction regarding safety precautions for sharing and posting personal information online. a member of the study staff met with these participants for about 30 minutes to review the different features of facebook. we recommended using their first name only or a pseudonym when creating an account so that participants could remain anonymous within facebook, yet we encouraged them to disclose their identity to other participants once they posted messages within the group. for participants who were already active on facebook, we encouraged them to either use their personal account, or to create a second account just to use for the study. by using the private group feature on facebook we maintained administrative control over the group, and could ensure that only participants enrolled in the study could view, access, and share content. if necessary we could also delete posts or comments, or remove participants from the group. a member of our research team monitored content daily for the study duration to ensure that posts were appropriate and relevant to the objectives of the health promotion intervention. ongoing technical support for using facebook first, after the six - month lifestyle intervention, participants completed a 14-item feasibility and acceptability questionnaire adapted from a prior study of a mobile health intervention for people with psychotic disorders. this quantitative measure generated important insight about participants evaluation of the feasibility, acceptability, and satisfaction with using facebook. however, a quantitative rating scale is insufficient for understanding participants specific experiences using facebook or for identifying ways to improve its use. therefore, in the second step, we conducted semi - structured qualitative interviews with participants to expand on the breadth and scope of their questionnaire responses. interviews were 4560 minutes in duration, and explored perceived benefits, challenges, and usefulness of the facebook group, as well as recommendations for improvement. expansion is an effective technique for combining quantitative and qualitative data to obtain a more comprehensive evaluation, and is valuable for refining and making revisions to intervention design. the interviews were audio - recorded and transcribed for analysis, which involved categorization and classification of data to systematically identify key topics and to draw inferences. two researchers (jan and kaa) independently reviewed the interview transcripts to immerse themselves in the data. then, one researcher (jan) summarized participants comments about the facebook group collected from the qualitative interviews, and organized them into categories. a second researcher (kaa) reviewed the categories and summary of the comments to ensure that they were representative of the data. both researchers then organized the comments into two broad themes : (1) comments and feedback about what participants liked about the facebook group ; and (2) comments about what participants disliked and recommendations for improvement. this content analytic approach was selected because our objective was to summarize key recommendations for informing future use of facebook. the lifestyle intervention was adapted from the evidence- based diabetes prevention program and was delivered through an urban community mental health center in new hampshire. the modified program focused on achieving weight loss through healthy eating and exercise and consisted of 24 weekly sessions, twice weekly optional exercise classes led by a certified fitness trainer and tailored to the needs and abilities of sedentary adults, and mobile health technology support including a private facebook group, text message reminders, and wearable devices for tracking steps. the standard diabetes prevention program curriculum consists of 16 weekly sessions, but this was expanded to six months (24 weekly sessions) to incorporate additional content aimed at addressing the impact of mental health symptoms on the ability to make positive health behavior changes. research suggests that shorter lifestyle interventions may not be as effective as longer and more intensive interventions for supporting behavioral weight loss among high - risk groups of individuals with serious mental illness. participants were taught standard weight - loss techniques such as goal setting, self - monitoring dietary intake and physical activity, and problem - solving to overcome challenges to engaging in exercise or preparing healthy meals on a fixed budget. two graduate students with certification as lifestyle coaches for delivering the official diabetes prevention program content taught the weekly sessions. the life - style coaches received weekly supervision from study staff for the duration of the project. we created a private facebook group for the program. within the group, only participants whom we invited could post or share content such as text, photos, or videos, view posts, click like to show that they enjoyed a post, or post comments visible only to other group members. we introduced the facebook group and the ground rules for its use to participants in the sixth session of the 24-session lifestyle program. the lifestyle coaches and a member of the research staff provided a 30-minute briefing to participants for using the facebook group. participants used the private facebook group for a total of 20 weeks (including one holiday week with no group session). participants were instructed to only post content related to healthy eating and exercise, that was supportive and encouraging, and that described successes or challenges towards achieving healthy lifestyle goals. participants were asked not to post personally identifying information such as address or phone number, photos of other people without their permission, photos of children, grandchildren or other family members, or any hurtful or rude comments. we explained that the facebook group was intended to reinforce content from the weekly group sessions and to allow participants to interact and share personal successes and challenges with meeting weight loss and physical activity goals outside regular meetings. study staff also posted content related to topics covered in the group sessions, reminders to exercise, and tips for healthy eating. for participants who were new to facebook, we helped them set up an account, and provided instruction regarding safety precautions for sharing and posting personal information online. a member of the study staff met with these participants for about 30 minutes to review the different features of facebook. we recommended using their first name only or a pseudonym when creating an account so that participants could remain anonymous within facebook, yet we encouraged them to disclose their identity to other participants once they posted messages within the group. for participants who were already active on facebook, we encouraged them to either use their personal account, or to create a second account just to use for the study. by using the private group feature on facebook we maintained administrative control over the group, and could ensure that only participants enrolled in the study could view, access, and share content. if necessary we could also delete posts or comments, or remove participants from the group. a member of our research team monitored content daily for the study duration to ensure that posts were appropriate and relevant to the objectives of the health promotion intervention. ongoing technical support for using facebook first, after the six - month lifestyle intervention, participants completed a 14-item feasibility and acceptability questionnaire adapted from a prior study of a mobile health intervention for people with psychotic disorders. this quantitative measure generated important insight about participants evaluation of the feasibility, acceptability, and satisfaction with using facebook. however, a quantitative rating scale is insufficient for understanding participants specific experiences using facebook or for identifying ways to improve its use. therefore, in the second step, we conducted semi - structured qualitative interviews with participants to expand on the breadth and scope of their questionnaire responses. interviews were 4560 minutes in duration, and explored perceived benefits, challenges, and usefulness of the facebook group, as well as recommendations for improvement. expansion is an effective technique for combining quantitative and qualitative data to obtain a more comprehensive evaluation, and is valuable for refining and making revisions to intervention design. the interviews were audio - recorded and transcribed for analysis, which involved categorization and classification of data to systematically identify key topics and to draw inferences. two researchers (jan and kaa) independently reviewed the interview transcripts to immerse themselves in the data. then, one researcher (jan) summarized participants comments about the facebook group collected from the qualitative interviews, and organized them into categories. a second researcher (kaa) reviewed the categories and summary of the comments to ensure that they were representative of the data. both researchers then organized the comments into two broad themes : (1) comments and feedback about what participants liked about the facebook group ; and (2) comments about what participants disliked and recommendations for improvement. this content analytic approach was selected because our objective was to summarize key recommendations for informing future use of facebook. in total, 29 people were referred for the current study by clinical staff at the community mental health center. eight of these individuals were not interested and eight did not meet the study inclusion criteria or experienced medical concerns that precluded participation. two individuals who agreed to participate quit at the start of the program due to other time commitments. therefore, 11 individuals initiated the lifestyle intervention and were invited to join the facebook group. over half (55%) of these participants reported owning a smartphone, though only one participant chose to use his personal smartphone for the study. most participants invited to join facebook were women (73%), all were non - hispanic white, and the mean age was 48.211.2 years (range 21 to 57 years) and mean bmi was 41.511.5 kg / m. participants mental illness diagnoses included schizophrenia spectrum disorders (27%), major depressive disorder (45%), and bipolar disorder (27%). two of the 11 participants were concerned about privacy, and were not interested in joining the facebook group. i was leery about [facebook ] because i do nt like a lot of my personal business just out there.. it s a thing i do nt particularly care for, while the other participant indicated that, because facebook was new to them, they felt more comfortable using pseudonyms for creating accounts to avoid any privacy concerns. six participants were active facebook users, and used their personal accounts. during the study period, there were a total of 188 posts to the facebook group, the majority (79%) of which were posted by participants. the remaining posts (21%) were from study staff. participants were highly active in the facebook group as reflected by 186 comments, 299 likes, and 1316 page views. throughout the study duration, participants did not post any inappropriate content within the group, and no comments or posts were deleted, and no participants were removed from the group. only participants who joined the facebook group (n=9) completed post - intervention feasibility and acceptability questionnaires. most agreed that the facebook group was easy to use and could be easily accessed through the smartphone application, but there was some disagreement reflected in the satisfaction ratings among participants regarding the usefulness of the group, how fun the group was to use, and the benefits of the group for encouraging physical activity and choosing healthier food options. importantly, the majority of participants found that the facebook group was safe to use, and that they would recommend it to a friend and were interested in continuing to use it. all 11 participants completed the in - depth qualitative interviews (see table 3). the interviews revealed that participants viewed the content posted by other participants to be interesting and helpful, in particular content related to nutrition tips, recipes, and healthy foods. participants also indicated that they appreciated the opportunity to interact with others, and being able to give and receive support for achieving successes and for overcoming challenges in trying to lose weight through healthy eating and exercise. participants also indicated in the interviews that there was not enough interaction on the facebook group. one participant felt that the group did not come together on facebook as expected with daily interactions between participants, while another participant who frequently posted content was interested in receiving more feedback from other participants in the form of because facebook was new to several participants, there were recommendations for more detailed instructions and demonstrations on how to access and post content. some participants received unwanted requests to become friends with other participants on their personal accounts, or were prompted to become friends with people who were complete strangers, likely because of similar characteristics or overlapping facebook for some participants facebook sent them automated prompts or advertisements to join online games, or sent them frequent email or text message updates. these frequent notifications were a distraction, and as a result one participant stopped using the facebook group after three months. in total, 29 people were referred for the current study by clinical staff at the community mental health center. eight of these individuals were not interested and eight did not meet the study inclusion criteria or experienced medical concerns that precluded participation. two individuals who agreed to participate quit at the start of the program due to other time commitments. therefore, 11 individuals initiated the lifestyle intervention and were invited to join the facebook group. over half (55%) of these participants reported owning a smartphone, though only one participant chose to use his personal smartphone for the study. most participants invited to join facebook were women (73%), all were non - hispanic white, and the mean age was 48.211.2 years (range 21 to 57 years) and mean bmi was 41.511.5 kg / m. participants mental illness diagnoses included schizophrenia spectrum disorders (27%), major depressive disorder (45%), and bipolar disorder (27%). two of the 11 participants were concerned about privacy, and were not interested in joining the facebook group. i was leery about [facebook ] because i do nt like a lot of my personal business just out there.. it s a thing i do nt particularly care for, while the other participant indicated that, because facebook was new to them, they felt more comfortable using pseudonyms for creating accounts to avoid any privacy concerns. during the study period, there were a total of 188 posts to the facebook group, the majority (79%) of which were posted by participants. participants were highly active in the facebook group as reflected by 186 comments, 299 likes, and 1316 page views. throughout the study duration, participants did not post any inappropriate content within the group, and no comments or posts were deleted, and no participants were removed from the group. only participants who joined the facebook group (n=9) completed post - intervention feasibility and acceptability questionnaires. most agreed that the facebook group was easy to use and could be easily accessed through the smartphone application, but there was some disagreement reflected in the satisfaction ratings among participants regarding the usefulness of the group, how fun the group was to use, and the benefits of the group for encouraging physical activity and choosing healthier food options. importantly, the majority of participants found that the facebook group was safe to use, and that they would recommend it to a friend and were interested in continuing to use it. all 11 participants completed the in - depth qualitative interviews (see table 3). the interviews revealed that participants viewed the content posted by other participants to be interesting and helpful, in particular content related to nutrition tips, recipes, and healthy foods. participants also indicated that they appreciated the opportunity to interact with others, and being able to give and receive support for achieving successes and for overcoming challenges in trying to lose weight through healthy eating and exercise. participants also indicated in the interviews that there was not enough interaction on the facebook group. one participant felt that the group did not come together on facebook as expected with daily interactions between participants, while another participant who frequently posted content was interested in receiving more feedback from other participants in the form of because facebook was new to several participants, there were recommendations for more detailed instructions and demonstrations on how to access and post content. some participants received unwanted requests to become friends with other participants on their personal accounts, or were prompted to become friends with people who were complete strangers, likely because of similar characteristics or overlapping facebook for some participants facebook sent them automated prompts or advertisements to join online games, or sent them frequent email or text message updates. these frequent notifications were a distraction, and as a result one participant stopped using the facebook group after three months. in this exploratory mixed methods pilot study, qualitative interviews expanded on participants quantitative ratings about feasibility, acceptability, and satisfaction with using facebook to support a group - based lifestyle intervention. in - depth interviews revealed that participants were generally positive about the opportunities to interact with others and to support each other on facebook, and found the content posted by other participants to be helpful. consistent with prior research from the general population, our findings highlight the potential feasibility and many promising aspects of using a popular online social networking website such as facebook to support a group - based lifestyle intervention for individuals with serious mental illness. however, our findings must be interpreted with caution and future research is needed to determine how social media can be used to promote engagement in lifestyle interventions among people with serious mental illness and whether such efforts contribute to clinically important outcomes such as reduction in cardiovascular risk. participants also commented on many aspects of the facebook group that they did not like, and provided helpful suggestions for improving the way that we introduce facebook, provide instructions for accessing the group, and encourage participants to use it. based on participants feedback, we identified three important considerations for informing the use of facebook in future health promotion efforts. first, more extensive technical training for accessing, posting content, and interacting on the facebook group is needed when introducing the group to participants. this is especially important for participants who are new to facebook or have limited experience with online technologies. this is consistent with prior studies describing the introduction of new mobile health technologies in this population, where more detailed instruction may be necessary given limited prior exposure and cognitive deficits associated with having a serious mental illness. there is also a need for more individualized assistance and one - on- one training for setting up an account and accessing the facebook group. second, efforts are needed to foster more group cohesion and to help participants feel comfortable interacting with one another on the facebook group. participants indicated that they wanted to see more interaction between each other, but did not want staff to get involved in posting more content. one possible approach for promoting group cohesion may be to recruit peer volunteers to assist with moderating and posting content to the facebook group. peer volunteers could be individuals with serious mental illness who were previously enrolled in a group intervention and who demonstrated frequent use of the facebook group and an interest in supporting others who are working towards similar healthy lifestyle goals. evidence in the general population suggests that even if participants are passively viewing content on facebook without interacting, they may still experience benefits such as social support for weight loss behaviors. this supports the need to ensure that peer volunteers regularly post relevant and interesting content to the group. third, future efforts should attempt to ensure that participants are fully aware of many of the features of the facebook website. as part of the instruction and introduction to facebook, it is necessary to explain to participants that unwanted friend requests, prompts, notifications, and advertisements are all part of using popular social media like facebook. additional recommendations should be provided for how best to respond to or ignore alerts and notifications, as well as greater emphasis on ways to maintain and protect privacy, and to avoid unwanted requests from strangers. most notably, the small sample size and lack of racial or ethnic diversity may limit generalizability of these findings across other geographic regions or community mental health settings. additionally, we recruited a convenience sample of individuals who were interested and willing to participate in a lifestyle intervention and who were receiving treatment through a community mental health center. therefore these findings may not be representative of individuals with serious mental illness not currently receiving treatment. given that this was a preliminary feasibility study, a member of the study staff assisted participants with setting up personal facebook accounts and provided additional instruction for using the private facebook group. in a real world implementation of this program it would be ideal for the lifestyle coach to facilitate the facebook component of the intervention, in addition to leading the weekly group sessions. among participants who agreed to join the facebook group, none mentioned any safety concerns related to using the group, and the majority reported that the group was safe to use, though future research should specifically explore participants evaluation of safety and privacy in the context of using facebook as a part of lifestyle interventions. recent research suggests that people with serious mental illness use social media and facebook at comparable rates as the general population, further highlighting the potential for these popular online platforms to substantially expand the reach of health promotion efforts. despite this promise, it is important to recognize that popular social media such as facebook will likely not be ideal for reaching all individuals with serious mental illness, and that future research is necessary to explore how to most effectively leverage this high - risk group s use of these popular websites to support meaningful and lasting health behavior change. most notably, the small sample size and lack of racial or ethnic diversity may limit generalizability of these findings across other geographic regions or community mental health settings. additionally, we recruited a convenience sample of individuals who were interested and willing to participate in a lifestyle intervention and who were receiving treatment through a community mental health center. therefore these findings may not be representative of individuals with serious mental illness not currently receiving treatment. given that this was a preliminary feasibility study, a member of the study staff assisted participants with setting up personal facebook accounts and provided additional instruction for using the private facebook group. in a real world implementation of this program it would be ideal for the lifestyle coach to facilitate the facebook component of the intervention, in addition to leading the weekly group sessions. among participants who agreed to join the facebook group, none mentioned any safety concerns related to using the group, and the majority reported that the group was safe to use, though future research should specifically explore participants evaluation of safety and privacy in the context of using facebook as a part of lifestyle interventions. recent research suggests that people with serious mental illness use social media and facebook at comparable rates as the general population, further highlighting the potential for these popular online platforms to substantially expand the reach of health promotion efforts. despite this promise, it is important to recognize that popular social media such as facebook will likely not be ideal for reaching all individuals with serious mental illness, and that future research is necessary to explore how to most effectively leverage this high - risk group s use of these popular websites to support meaningful and lasting health behavior change. to our knowledge, this is the first exploration of the feasibility and acceptability of using facebook for health promotion among people with serious mental illness. despite the notable limitations described above, the design of our study was unique because our facebook group was largely participant - driven, as opposed to daily messages posted by research staff. participants indicated that they enjoyed interacting on the facebook group, which may be because they had a chance to get to know each other in the face - to - face group intervention sessions prior to joining the facebook group. this approach may overcome previously identified challenges with engaging users on social media, where users may not be comfortable interacting with strangers. prior studies have also suggested that social media may be effective for promoting participant engagement in behavioral weight loss interventions, rather than directly contributing to weight loss. the findings from our exploratory pilot study suggest that facebook may be both feasible and acceptable for supporting a group lifestyle intervention for people with serious mental illness. additionally, our findings emphasize the importance of obtaining and integrating feedback from participants early on when testing novel online technologies for health promotion. through participant feedback, we learned important details about specific features of the facebook website, and what participants value when interacting on this type of platform. these insights are critical for informing the design and use of facebook in future health promotion efforts targeting this high - risk group because research suggests that the way participants interact within a facebook group for behavioral weight loss can influence outcomes. future research should seek to identify the types of individuals who would be most likely to benefit from intervention content delivered through facebook in order to reach a wider range of people with serious mental illness with targeted health promotion efforts. popular social media like facebook may be promising for supporting behavioral weight - loss efforts among people with serious mental illness, yet future research is needed to carefully weigh the potential risks and benefits of using facebook in this way, and to assess whether this platform effectively supports positive group dynamics and contributes to meaningful weight loss and physical activity outcomes. | objectiveelevated obesity rates are a major contributor to the significantly reduced life expectancy impacting people with serious mental illness. with over 1.5 billion facebook users worldwide, this platform may afford opportunities for reaching individuals with serious mental illness outside professional settings and fostering social support for adopting healthier behaviors. in this mixed methods pilot study, we explored the feasibility and acceptability of using facebook to support a group lifestyle intervention for weight loss among obese adults with serious mental illness.methodsnine of eleven participants enrolled in a six - month lifestyle intervention delivered through a community mental health center agreed to join a private facebook group to support their healthy eating and exercise goals. we measured participants use of the facebook group and collected post - intervention feasibility and acceptability questionnaires followed by in - depth qualitative interviews to elicit participants perspectives and recommendations for improving the use of facebook.resultsof 188 posts to the facebook group, the majority (79%) were from participants compared to study staff (21%). participants also posted 186 comments, 299 likes, and recorded 1316 page views. participants were positive about opportunities to interact and support each other outside group sessions, found content posted by other participants to be helpful, and indicated that the facebook group was safe to use. participants provided constructive feedback, including recommendations for more detailed instructions for accessing the group and posting content, finding ways to encourage more interaction within the group, and tips for responding to notifications or alerts directly from the facebook website.conclusionsthese findings suggest that facebook may be feasible for supporting health promotion efforts targeting people with serious mental illness. participants provided valuable feedback that can inform the use of facebook for future health promotion efforts targeting this high - risk group. |
it has been approved by the us food and drug administration for the treatment of narcolepsy associated excessive daytime sleepiness, sleep disorder related to shift work, and obstructive sleep apnea syndrome. however, at present it is being used as a lifestyle drug, especially amongst sports personnel, hardworking business executives and call center workers. in fact, it is sold illegally on various online shopping websites ; in india, it has become an over the counter drug - and thus, open for abuse, where it may be used by anyone who wishes to work or study overnight. modafinil is known to have several cutaneous side effects, apart from the numerous psychiatric and systemic ones. since its initial marketing in december 1998, several cases of severe cutaneous adverse reactions associated with modafinil have been recorded. these included stevens johnson syndrome, toxic epidermal necrolysis, and drug rash with eosinophilia and systemic symptoms in adult and pediatric patients. yet only two cases similar to describing modafinil induced fixed drug eruption (fde) have been reported till date. a 23-year - old trainee doctor presented to the dermatology out - patient department with a complaint of painful erosion in his mouth [figure 1 ] for the preceding 2 days. he stated that there were two such episodes in which he had similar erosion at the same site, 1 and 2 months ago. it was on the third episode that he got anxious and decided to seek medical attention. erosion on the left side of the hard palate detailed interview revealed the subject consuming 200 mg of tablet modafinil for few days prior to his exams for mental alertness and avoiding an undue sedation. he was preparing for his postgraduate entrance examinations and was scheduled to appear for a series of tests. there was no history of psychiatric morbidity or intake of any regular or casual medication, including psychotropics. mental state examination revealed a well - built, appropriately groomed male maintaining eye contact during the interview. there was no noticeable abnormal movement, speech was relevant and coherent, mood euthymic, but affect was anxious. there were no perceptual disturbances. examination revealed hydropic degradation of the basal cell layer and a lymphocytic infiltrate with dermal macrophages. the adverse drug reaction (adr) scale proposed by naranjo. has been utilized causality assessment of a drug in these situations. in the present case, the score was 6, which meant that modafinil was the probable cause of the adr. the patient was advised to desist from taking modafinil in the future and was prescribed triamcinolone acetonide oral paste to be applied 4 times daily for 5 days. he was cured within a day though he completed the course of medication as advised. a 19-year - old 2 year medical student presented to the dermatology clinic with a red annular painful mark on his right palm [figure 2 ], which had appeared the night before. he described three previous similar episodes, which occurred 1, 3 and 6 weeks ago respectively. annular erythema on right palm he was due to appear for the board examinations, in which he was keen on performing well. having heard about modafinil from a senior colleague ; he started using it (100 mg tablets) out of sheer curiosity. the results of his initial we having gone well, he had started using the drug as and when required. however, he had noticed that each such use was accompanied by the same painful bruise like rash on his right palm, which he could not explain. this peculiar rash would disappear spontaneously ; nevertheless this time he decided to consult a dermatologist. findings included hydropic degeneration of the basal layer, melanin incontinence and dense mononuclear infiltrate in the dermis. on mental state examination, the patient was average - built, looking to his age and appropriately groomed. no abnormal movement was noticed, speech was relevant and coherent and affect anxious. there were no perceptual disturbances, higher cognition was intact and insight was grade vi. based on the history and clinical findings, he was diagnosed to have modafinil induced fde. in the present case also, the adr probability classification score was 6, which meant that modafinil again, was the probable cause of the adr. a 23-year - old trainee doctor presented to the dermatology out - patient department with a complaint of painful erosion in his mouth [figure 1 ] for the preceding 2 days. he stated that there were two such episodes in which he had similar erosion at the same site, 1 and 2 months ago. it was on the third episode that he got anxious and decided to seek medical attention. erosion on the left side of the hard palate detailed interview revealed the subject consuming 200 mg of tablet modafinil for few days prior to his exams for mental alertness and avoiding an undue sedation. he was preparing for his postgraduate entrance examinations and was scheduled to appear for a series of tests. there was no history of psychiatric morbidity or intake of any regular or casual medication, including psychotropics. mental state examination revealed a well - built, appropriately groomed male maintaining eye contact during the interview. there was no noticeable abnormal movement, speech was relevant and coherent, mood euthymic, but affect was anxious. there were no perceptual disturbances. examination revealed hydropic degradation of the basal cell layer and a lymphocytic infiltrate with dermal macrophages. the adverse drug reaction (adr) scale proposed by naranjo. has been utilized causality assessment of a drug in these situations. in the present case, the score was 6, which meant that modafinil was the probable cause of the adr. the patient was advised to desist from taking modafinil in the future and was prescribed triamcinolone acetonide oral paste to be applied 4 times daily for 5 days. he was cured within a day though he completed the course of medication as advised. a 19-year - old 2 year medical student presented to the dermatology clinic with a red annular painful mark on his right palm [figure 2 ], which had appeared the night before. he described three previous similar episodes, which occurred 1, 3 and 6 weeks ago respectively. annular erythema on right palm he was due to appear for the board examinations, in which he was keen on performing well. having heard about modafinil from a senior colleague ; he started using it (100 mg tablets) out of sheer curiosity. the results of his initial we having gone well, he had started using the drug as and when required. however, he had noticed that each such use was accompanied by the same painful bruise like rash on his right palm, which he could not explain. this peculiar rash would disappear spontaneously ; nevertheless this time he decided to consult a dermatologist. findings included hydropic degeneration of the basal layer, melanin incontinence and dense mononuclear infiltrate in the dermis. on mental state examination, the patient was average - built, looking to his age and appropriately groomed. no abnormal movement was noticed, speech was relevant and coherent and affect anxious. there were no perceptual disturbances, higher cognition was intact and insight was grade vi. based on the history and clinical findings, he was diagnosed to have modafinil induced fde. in the present case also, the adr probability classification score was 6, which meant that modafinil again, was the probable cause of the adr. a 23-year - old trainee doctor presented to the dermatology out - patient department with a complaint of painful erosion in his mouth [figure 1 ] for the preceding 2 days. he stated that there were two such episodes in which he had similar erosion at the same site, 1 and 2 months ago. it was on the third episode that he got anxious and decided to seek medical attention. erosion on the left side of the hard palate detailed interview revealed the subject consuming 200 mg of tablet modafinil for few days prior to his exams for mental alertness and avoiding an undue sedation. he was preparing for his postgraduate entrance examinations and was scheduled to appear for a series of tests. there was no history of psychiatric morbidity or intake of any regular or casual medication, including psychotropics. mental state examination revealed a well - built, appropriately groomed male maintaining eye contact during the interview. there was no noticeable abnormal movement, speech was relevant and coherent, mood euthymic, but affect was anxious. there were no perceptual disturbances. examination revealed hydropic degradation of the basal cell layer and a lymphocytic infiltrate with dermal macrophages. the adverse drug reaction (adr) scale proposed by naranjo. has been utilized causality assessment of a drug in these situations. in the present case, the score was 6, which meant that modafinil was the probable cause of the adr. the patient was advised to desist from taking modafinil in the future and was prescribed triamcinolone acetonide oral paste to be applied 4 times daily for 5 days. he was cured within a day though he completed the course of medication as advised. a 19-year - old 2 year medical student presented to the dermatology clinic with a red annular painful mark on his right palm [figure 2 ], which had appeared the night before. he described three previous similar episodes, which occurred 1, 3 and 6 weeks ago respectively. annular erythema on right palm he was due to appear for the board examinations, in which he was keen on performing well. having heard about modafinil from a senior colleague ; he started using it (100 mg tablets) out of sheer curiosity. the results of his initial we having gone well, he had started using the drug as and when required. however, he had noticed that each such use was accompanied by the same painful bruise like rash on his right palm, which he could not explain. this peculiar rash would disappear spontaneously ; nevertheless this time he decided to consult a dermatologist. findings included hydropic degeneration of the basal layer, melanin incontinence and dense mononuclear infiltrate in the dermis. on mental state examination, the patient was average - built, looking to his age and appropriately groomed. no abnormal movement was noticed, speech was relevant and coherent and affect anxious. there were no perceptual disturbances, higher cognition was intact and insight was grade vi. based on the history and clinical findings, he was diagnosed to have modafinil induced fde. in the present case also, the adr probability classification score was 6, which meant that modafinil again, was the probable cause of the adr. fixed drug eruption is a distinctive drug induced reaction pattern characterized by recurrence of eruption at the same site of the skin or mucous membrane with repeated systemic administration of the drug. fde is the most common cutaneous drug reaction described in india, being somewhat more common in this part of the globe ; a finding ascribed to genetic factors. it is considered to be a cd8 lymphocyte mediated reaction, the offending drug, along with virus - induced factors, causing local reactivation of memory t - cell lymphocytes located in the epidermis and dermis. common drugs incriminated in causing fde are trimethoprim - sulfamethoxazole, tetracycline, penicillin, nonsteroidal anti - inflammatory drugs like aspirin, diclofenac sodium, naproxen and ibuprofen. clinically, fdes are single or multiple, bullous, pigmented or nonpigmented ; they occur mainly on the extremities or on the mucous membranes. they generally start as sharply marginated, round - oval patches of erythema and edema and become dusky violaceous or brown in color or ulcerate. treatment includes stoppage of the offending drug with application of topical steroids, emollients, and oral antihistamines. modafinil belongs to a novel class of psychostimulants known as eugeroics (eugeroic denotes good arousal) with absence of side effects common to traditional psychostimulating drugs, which include anxiety, jitteriness, excess locomotor activities and rebound phenomenon. the mode of action of modafinil is yet to be fully understood : however, its actions in the anterior hypothalamus and orexin neurons have been appreciated. it probably promotes wakefulness by increasing the level of glutamate, serotonin, and histamine ; there is also evidence of the decrease of gamma amino butyric acid in the brain. modafinil has been tried in the treatment of diseases like attention deficit disorder, alzheimer 's disease, idiopathic hypersomnia, cognitive impairment in schizophrenics and to solve lifestyle issues as jet lag, night shift jobs and so on. the present cases illustrate the abuse potential of this drug and its side effects. in both the cases, the increasing use of this class of drug amongst the medical personnel might pose a threat of abuse potential. | modafinil is a psychostimulant drug, which has been approved by the us food and drug administration for the treatment of narcolepsy associated excessive daytime sleepiness, sleep disorder related to shift work, and obstructive sleep apnea syndrome. however, presently it is being used as a lifestyle medicine ; in india, it has been misused as an over the counter drug. modafinil is known to have several cutaneous side effects. fixed drug eruption (fde) is a distinctive drug induced reaction pattern characterized by recurrence of eruption at the same site of the skin or mucous membrane with repeated systemic administration. only two case reports exist in the literature describing modafinil induced fde until date. here, we report two similar cases. the increasing use of this class of drug amongst the medical personnel might be posing a threat to the proper use and encouraging subsequent abuse. there might be a considerable population using these drugs unaware of the possible adverse effects. authorities should be more alert regarding the sale and distribution of such medicines. |
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