Simulation model of renal replacement therapy: predicting future demand in England.

BACKGROUND: The demand for renal replacement therapy (RRT) in England has risen steadily, although from a lower base than many other developed countries. Predicting the future demand for RRT and the impact of factors such as the acceptance rate, transplant supply and patient survival, is required in order to inform the planning of such services. METHODS: A discrete event simulation model estimates the future demand for RRT in England in 2010 for a range of scenarios. The model uses current prevalence and current and projected future acceptance rates, survival rates and the transitions between modalities to predict future patient numbers. National population and mortality data, published literature and data from the UK Renal Registry and UK Transplant, are used to estimate unmet need for RRT, the impact of changing demography and incidence of Type 2 diabetes, patient haemodialysis (HD) survival and transplant supply. RESULTS: By 2010 the predicted prevalence will have increased from about 30,000 in 2000 to between 42 and 51,000 (900-1000 p.m.p.), an average annual growth of 4.5-6%. Changing transplant supply has a small effect on overall numbers but changes the proportion of patients with functioning graft by up to 8%. Even with an optimistic increase in transplant supply (11% p.a. for 5 years), numbers on HD will continue to rise substantially, especially in the elderly. The factors most influencing future patient numbers are the acceptance rate and dialysis survival. CONCLUSION: This model predicts a substantial growth in the RRT population to 2010 to a rate approaching 1000 p.m.p., particularly in the elderly and those on HD, with a steady state not being reached for at least 25 years.     

Fibreoptic bronchoscopy for tracheal and endobronchial intubation with a double-lumen tube

A 68-year-old patient was scheduled for a thoracotomy. A double-lumen endobronchial tube was requested by the surgeon to facilitate operating conditions. Initial attempts at intubation by conventional methods were unsuccessful. The proximal ends of a 37F double-lumen tube were then shortened and a 4-mm fibreoptic bronchoscope was passed through the bronchial lumen. The patient's larynx was easily visualized and the bronchoscope was passed into the trachea. The double lumen tube was then advanced over the bronchoscope and correctly positioned. Shortening a double-lumen tube allows the use of a fibreoptic bronchoscope to aid in tracheal intubation in a patient whose larynx is difficult to visualize by conventional methods.     

Evidence for motility and pinocytosis in ramified microglia in tissue culture

Ramified microglial cells were investigated in primary cultures of dissociated cerebral cortical tissue from rats. The identification of these cells was confirmed through immunohistochemical staining with 7 monoclonal antibodies selective for microglia. While there was significant variation in staining intensity with different antibodies, all stained the identified ramified cells; the antibodies OX-42 and ED1 yielded the most intense immunoreactivity. Based on distinctive morphological features, the microglia could be identified in living cultures where they were monitored using time-lapse video recording. This technique revealed extremely dynamic features of cellular plasticity and motility. Ramified microglia exhibited constant and rapid alterations in the size and shape of their cell body with an associated extension and retraction of processes; concomitantly, the cells moved about in a circumscribed area. These features of plasticity and motility were unique to this cell type, and correlated with OX-42 immunostaining. The microglia also possessed a differentially high level of pinocytotic activity; this too was correlated with OX-42 staining. From the nature of their morphological plasticity and motility, high pinocytosis, and cellular distribution, it is hypothesized that the ramified microglia specifically function as a system of fluid cleansing in normal brain tissue.     

Small proportions: what to report for confidence intervals?

The original article to which this Erratum refers was published in Pharmacoepidemiology and Drug Safety 2005; 14: 239–247.     

Diarrhea in liver transplant recipients: etiology and management.

Diarrhea is common after liver transplantation (LT). The true incidence of diarrhea in liver transplant recipients is unknown but possibly ranges from 10% to 43% based on a few published studies in other solid organ and bone marrow transplantation. Infectious etiologies, including cytomegalovirus (CMV), Clostridium difficile, and occasional atypical intestinal infections, are the most common causes. Diarrhea is also a frequent side effect of immunosuppressive medications. To variable extents, mycophenolate mofetil (MMF), cyclosporine A (CSA), tacrolimus, and sirolimus are all known to be associated with diarrhea. Rarely, graft-versus-host disease (GVHD), lymphoproliferative disorder, de novo inflammatory bowel disease (IBD), or colon cancer may present as diarrhea. Flare-up of preexisting IBD is also not uncommon after LT. However, the cause of acute diarrhea remains unidentified in 1 of 3 patients. This review summarizes the literature and provides recommendations on the management of acute diarrhea after LT. Although our focus is on LT, the etiology and management recommendations apply to most transplant recipients.     

Interactions of angiotensin IV and oxytocin on behaviour in mice.

INTRODUCTION: Angiotensin (Ang) IV enhances learning and memory in rats but there are strain differences in its effects in mice. Oxytocin (OT) also influences learning and memory in rats and mice and, in the light of the proposed effects of Ang IV on oxytocinase, the hypothesis that the effects of Ang IV on cognition in mice involve OT was tested. MATERIALS AND METHODS: The effects of Ang IV and OT, alone and combined, were determined in rat isolated uterine smooth muscle and in object recognition and forced swim tests in BKW mice. RESULTS: Ang potentiated the contractile effects of OT in the uterus. Neither peptide had any effect on object recognition nor locomotor activity. Ang IV had no effect in the forced swim test but abolished the effects of OT. CONCLUSIONS: Ang IV influences the actions of OT in vitro and in vivo, possibly by inhibition of oxytocinase, but the lack of effect of Ang IV on object recognition in BKW mice is unlikely to be a consequence of a deficiency endogenous OT. Unlike OT, Ang IV alone has no effect on learned helplessness in the forced swim test, an effect often used to predict potential antidepressant efficacy in humans.