Hyperemic Islets: A Possible Explanation for Poor Yields in Human and Porcine Islet Isolation

When studying histological characteristics of human and porcine pancreata in relation to islet isolation, we encountered a remarkably high number of hyperemic islets. The abnormalities observed in these islets ranged from a single dilated vessel through multiple widely dilated vessels to hemorrhages extending into the surrounding exocrine tissue. We determined their possible relevance for outcomes of islet isolation. This study involved a histological examination of 143 porcine pancreata (72 juvenile and 71 adult) and islet isolation from 48 adult pancreata. Human pancreata obtained from 71 multiple organ donors yielded islet isolation in 24 cases. To determine their endocrine content, tissue samples were stained with Aldehyde Fuchsin. The presence of hyperemic islets was scored semiquantitatively with pancreata allotted to categories based on the severity. In humans and pigs we observed hyperemic islets in 48% of pancreata, but only 4.0 ± 2.4% of the islets were hyperemic. In both humans and pigs, significantly higher endocrine content was found in the most severely affected pancreata. When the higher endocrine content was taken into account and isolation results were expressed as ratios of yield and content, we observed significantly lower yields in the most affected pancreata in pigs with a trend toward lower yields in humans. A substantial proportion of human and porcine pancreata contain hyperemic islets. Although the results in humans are preliminary, our data suggest that this phenomenon may contribute to the unpredictable, highly variable islet yields in pigs and humans.     

Upper Gastrointestinal Bleeding During the First Month After Renal Transplantation in the Mycophenolate Mofetil Era

Upper gastrointestinal (GI) bleeding remains a significant cause of mortality and morbidity among renal transplant recipients. We retrospectively analyzed the records of patients who received renal transplantations between January 2001 and July 2007 using mycophenolate mofetil (MMF) in their immunosuppressive regimens. The following data were recorded for those subjects with upper GI bleeding during the first month after transplantation (group B, cases): age, sex, acute rejection episodes, pretransplant upper GI endoscopic findings, Helicobacter positivity, and cytomegalovirus (CMV) seropositivity. The same parameters were studied among a group of patients, who did not have a history of upper GI bleeding (group A, controls). A statistical analysis was performed to ascertain potential risk factors. Among 523 patients (311 females, 212 males) of age range 7 to 58 years, 27 (5.2%) had upper GI bleeding: 13 males and 14 females of mean age 44 ± 12 years. The most frequent endoscopic finding was erosive gastritis (n = 13; 48.1%) followed by duodenal ulcers. Binary logistic regression analysis comparing the 2 groups showed that acute rejection episodes (P = .015) and active CMV infection (P = .046) were the most prominent risk factors for upper GI bleeding during the first month after renal transplantation.     

Prior diabetes mellitus is associated with increased morbidity in cystic fibrosis patients undergoing bilateral lung transplantation: an ‘orphan’ area? A retrospective case–control study

Background: The aim of this study was to determine whether pre-existing diabetes mellitus increases the risk of rejection, infection and/or death in cystic fibrosis patients undergoing bilateral sequential single-lung transplantation.
Methods: A retrospective audit of 25 consecutive patients with cystic fibrosis who underwent bilateral sequential single-lung transplantation between 1 January 2003 and 31 December 2005 at a tertiary referral hospital was carried out.
Results: Although 32% patients had diabetes diagnosed before lung transplantation, 92% had random blood glucose levels ≥11.1 mmol/L requiring insulin during admission. Patients with pre-existing diabetes had increased infection-related (3.9 vs 1.2, P = 0.01) and putative rejection-related (1.4 vs 0.5, P = 0.04) hospital admissions post-transplantation compared with those without diabetes pre-transplant. During the period of observation, four of eight patients with a prior diagnosis of diabetes died compared with none of 17 patients without prior diabetes ( P = 0.0055).
Conclusion: Almost all cystic fibrosis patients develop hyperglycaemia after lung transplantation, but patients with prior diabetes have more complication-related admissions to hospital and a higher mortality rate.     

Evaluation of Patient-Reported Outcome in Subjects Treated Medically for Acute Pancreatitis: A Follow-Up Study

Aims: To explore the quality of life in patients treated medically during the acute phase of pancreatitis as well as at 2 and 12 months after discharge from the hospital. Patients: 40 patients were studied. The etiology of the pancreatitis was biliary causes in 31 patients and non-biliary causes in 9; mild disease was present in 29 patients and severe disease in 11. 30 patients completed the two surveys at 2 and 12 months after hospital discharge. Methods: The SF-12 and EORTC QLQ-C30 questionnaires were used for the purpose of the study. Results: The two physical and mental component summaries of SF-12, all the domains of EORTC QLQ-C30 (except for physical functioning and cognitive functioning) and some symptom scales of EORTC QLQ-C30 (fatigue, nausea/ vomiting, pain, and constipation) were significantly impaired during the acute phase of pancreatitis. There was a significant improvement in the SF-12 physical component summary, and global health, role functioning, social functioning, nausea/vomiting, pain, dyspnea, and financial difficulties (EORTC QLQ-C30) at 2 months after discharge as compared to the basal evaluation. Similar results were found after 12 months except for the mental component score at 12-month evaluation, which was significantly impaired in acute pancreatitis patients in comparison to the norms. The physical functioning of the EORTC QLQ-C30 at basal evaluation was significantly impaired in patients with severe pancreatitis in comparison to patients with mild pancreatitis. Conclusions: Two different patterns can be recognized in the quality of life of patients with acute pancreatitis: physical impairment is immediately present followed by mental impairment which appears progressively in the follow-up period.     

Ischemia independent lesion evolution during focal stroke in rats

Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia.Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[¹⁴C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections.Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g^− 1 min^− 1 existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 ± 21 mm³ (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct.Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.     

The genetic and epigenetic basis of ependymoma

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.