Localization of a Trypanosome Peroxin to the Endoplasmic Reticulum

Trypanosoma brucei is the causative agent of diseases that affect 30,000–50,000 people annually. Trypanosoma brucei harbors unique organelles named glycosomes that are essential to parasite survival, which requires growth under fluctuating environmental conditions. The mechanisms that govern the biogenesis of these organelles are poorly understood. Glycosomes are evolutionarily related to peroxisomes, which can proliferate de novo from the endoplasmic reticulum or through the growth and division of existing organelles depending on the organism and environmental conditions. The effect of environment on glycosome biogenesis is unknown. Here, we demonstrate that the glycosome membrane protein, TbPex13.1, is localized to glycosomes when cells are cultured under high glucose conditions and to the endoplasmic reticulum in low glucose conditions. This localization in low glucose was dependent on the presence of a C‐terminal tripeptide sequence. Our findings suggest that glycosome biogenesis is influenced by extracellular glucose levels and adds to the growing body of evidence that de novo glycosome biogenesis occurs in trypanosomes. Because the movement of peroxisomal membrane proteins is a hallmark of ER‐dependent peroxisome biogenesis, TbPex13.1 may be a useful marker for the study such processes in trypanosomes.

Liver transplantation in patients with atrial fibrillation

In this study we described survival and incidence of perioperative and postoperative complications in liver transplant recipients with known atrial fibrillation. A total number of 717 patients underwent liver transplantation between January 2005 and December 2008 at our institution. In this population, preoperative paroxysmal or chronic-persistent atrial fibrillation was diagnosed in 32 patients (4.5%). Of these, 12 patients died during follow-up and 4 patients required liver retransplantation. Perioperative cardiac complications occurred in 10 patients (31%) resulting in 3 cardiac-related deaths. Median patient survival was 1613 days (range, 22-2492) and median graft survival was 1524 days (range, 10-2492). Twenty patients are still alive with a median survival of 1861 days (range, 1189-2492) after liver transplantation.

Relating Nanoparticle Properties to Biological Outcomes in Exposure Escalation Experiments

A fundamental goal in nano-toxicology is that of identifying particle physical and chemical properties, which are likely to explain biological hazard. The first line of screening for potentially adverse outcomes often consists of exposure escalation experiments, involving the exposure of micro-organisms or cell lines to a library of nanomaterials. We discuss a modeling strategy, that relates the outcome of an exposure escalation experiment to nanoparticle properties. Our approach makes use of a hierarchical decision process, where we jointly identify particles that initiate adverse biological outcomes and explain the probability of this event in terms of the particle physicochemical descriptors. The proposed inferential framework results in summaries that are easily interpretable as simple probability statements. We present the application of the proposed method to a data set on 24 metal oxides nanoparticles, characterized in relation to their electrical, crystal and dissolution properties.

Symptoms in heart failure correlate poorly with objective haemodynamic parameters

INTRODUCTION

Even though heart failure (HF) is a very common condition, surprisingly little is known regarding association between patient's symptoms and objective data. The purpose of this study was to evaluate for any correlations between haemodynamic, echocardiographic and laboratory data of presenting symptoms in HF patients.

METHODS

This study is a retrospective analysis of the limited access dataset from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial provided by the National Heart, Lung and Blood Institute. Symptoms including dyspnoea, orthopnoea, fatigue and gastrointestinal (GI) discomfort were graded by their severity from minimal (0) to maximal (3) on admission, at discharge, at 3 months and at 6 months from the admission. Results of Minnesota Living with Heart Failure (MLHF) score and assigned New York Heart Association (NYHA) functional class were available at the same time points.

RESULTS

A total of 433 patients with decompensated HF and decreased systolic function (ejection fraction < 30%) were included in this trial. Orthopnoea, dyspnoea and fatigue had weak correlation with invasive pulmonary artery systolic and diastolic pressure and negative correlation with serum creatinine, albumin, sodium, total bilirubin, haemoglobin and haematocrit; fatigue showed positive correlation to pulmonary artery pressures. Abdominal discomfort had no correlation to symptoms. There was no correlation of symptoms, NYHA class, or MLHF scores with age, gender, peak VO(2) on cardiopulmonary stress test, body mass index, either right or left ventricular systolic function, B-type natriuretic peptide, cardiac output or cardiac index, troponin level, velocity of tricuspid regurgitation and multiple other factors predicting morbidity and mortality in HF.

CONCLUSION

Overall, the correlation between symptoms and objective parameters was weak. Because of low magnitude of relationship between symptoms to objective parameters, it was concluded that there are likely other factors determining the perception of symptoms in HF patients.

Does fasting during Ramadan affect the use of topical dermatological treatment by Muslim patients in the UK?

BACKGROUND

Ritual fasting during the Muslim religious festival of Ramadan is one of the 'Five Pillars' of Islam, and is widely observed by Muslims. Previous studies have highlighted compliance issues in patients prescribed oral medications during this period. Aim.  To assess whether fasting during Ramadan influence the use of topical treatments for skin disease in Muslim patients.

METHODS

This was a prospective, anonymous, questionnaire survey undertaken in a dermatology centre in a tertiary hospital in the UK. Patients were asked if they would use topical treatment while fasting, and whether they would consider this a breach of their fast.

RESULTS

We found that more than one-third of the people interviewed would not use topical treatment while fasting, and around the same number (> 30%) would also consider this a breach of their fast. Although the majority of these patients thought that using steroid-based topical products was not acceptable, a significant proportion extended this opinion to use of any cream or emollient, and even to light therapy. Gender, age, or educational level were not useful predictors of patient opinion, but there was a significant association with birthplace and likelihood of using topical treatment during Ramadan; patients born outside the UK were significantly (P < 0.01) less likely than those born in the UK to use topical treatment in the fasting period.

CONCLUSIONS

Our study indicates that fasting may be a significant and a hitherto unrecognised cause of non-compliance with topical treatment in Muslim patients in the UK, with potential health, quality and cost implications. Ritual fasting during Ramadan is widely observed by Muslims. Previous studies have highlighted compliance issues in patients prescribed oral medications during this period, and it seems this extends to use of topical treatments for skin disease.