GTPase activity of dynamin and resulting conformation change are essential for endocytosis

Dynamin is a large GTPase with a relative molecular mass of 96,000 (Mr 96K) that is involved in clathrin-mediated endocytosis and other vesicular trafficking processes. Although its function is apparently essential for scission of newly formed vesicles from the plasma membrane, the nature of dynamin's role in the scission process is still unclear. It has been proposed that dynamin is a regulator (similar to classical G proteins) of downstream effectors. Here we report the analysis of several point mutants of dynamin's GTPase effector (GED) and GTPase domains. We show that oligomerization and GTP binding alone, by dynamin, are not sufficient for endocytosis in vivo. Rather, efficient GTP hydrolysis and an associated conformational change are also required. These data argue that dynamin has a mechanochemical function in vesicle scission.

Treatment of Unexplained Chronic Cough: CHEST Guideline and Expert Panel Report

Background: Unexplained chronic cough (UCC) causes significant quality of life impairment. There is a need to identify effective assessment and treatment approaches for UCC.

Methods: This systematic review of randomized controlled clinical trials asked: What is the efficacy of treatment compared to usual care on cough severity, cough frequency, and cough-related quality of life in patients with unexplained chronic cough (UCC)? Studies of adults and adolescents >12 years with a chronic cough of >8 weeks duration that was unexplained after systematic investigation and treatment were included and assessed for relevance and quality. Based upon the systematic review, guideline suggestions were developed and voted upon using CHEST organization methodology.

Results: 11 RCTs and 5 systematic reviews were included. The 11 RCTs reported data on 570 participants with chronic cough who received a variety of interventions. Study quality was high in 10 RCTs. The studies used a variety of descriptors and assessments to identify unexplained chronic cough. While gabapentin and morphine showed positive effects on cough-related quality of life, only gabapentin was supported as a treatment recommendation. Studies of inhaled corticosteroids (ICS) suffered from intervention fidelity bias, and when this was addressed, ICS were not found to be effective for UCC. Esomeprazole was not effective for UCC without features of gastroesophageal acid reflux. Studies addressing non-acid gastroesophageal reflux were not identified. A multimodality speech pathology intervention improved cough severity.

Conclusions: The evidence supporting the diagnosis and management of UCC is limited. UCC requires further study to establish agreed terminology and the optimal methods of investigation using established criteria for intervention fidelity. Speech pathology based cough suppression is suggested as a treatment option for UCC. This guideline presents suggestions for diagnosis and treatment based on the best available evidence and identifies gaps in our knowledge and areas for future research.

Regulating Digital Financial Services Agents in Developing Countries to Promote Financial Inclusion

Limited access to bank branches excludes over one billion people from accessing financial services in developing countries. Digital financial services offered by banks and mobile money providers through agents can solve this problem without the need for complex and costly physical banking infrastructures. Delivering digital financial services through agents requires a legal framework to regulate liability. This article analyses whether vicarious liability of the principal is a more efficient regulatory approach than personal liability of the agent. Agent liability in Kenya, Fiji, and Malawi is analysed to demonstrate that vicarious liability of the principal, coupled to an explicit agreement as to agent rewards and penalties, is the more efficient regulatory approach.

Glycosylation of Vitamin D Binding Protein Reduced in Juvenile Idiopathic Arthritis Patients At Risk of Disease Extension.

Background/Purpose:Juvenile idiopathic arthritis (JIA) comprises a poorly understood group of chronic, childhood onset, autoimmune diseases with variable clinical outcomes. We investigated whether profiling of the synovial fluid (SF) proteome by a fluorescent dye based, two-dimensional gel (DIGE) approach could distinguish the subset of patients in whom inflammation extends to affect a large number of joints, early in the disease process. The post-translational modifications to candidate protein markers were verified by a novel deglycosylation strategy.Methods:SF samples from 57 patients were obtained around time of initial diagnosis of JIA. At 1 year from inclusion patients were categorized according to ILAR criteria as oligoarticular arthritis (n=26), extended oligoarticular (n=8) and polyarticular disease (n=18). SF samples were labeled with Cy dyes and separated by two-dimensional electrophoresis. Multivariate analyses were used to isolate a panel of proteins which distinguish patient subgroups. Proteins were identified using MALDI-TOF mass spectrometry with vitamin D binding protein (VDBP) expression and siaylation further verified by immunohistochemistry, ELISA test and immunoprecipitation. Candidate biomarkers were compared to conventional inflammation measure C-reactive protein (CRP). Sialic acid residues were enzymatically cleaved from immunopurified SF VDBP, enriched by hydrophilic interaction liquid chromatography (HILIC) and analysed by mass spectrometry.Results:Hierarchical clustering based on the expression levels of a set of 23 proteins segregated the extended-to-be oligoarticular from the oligoarticular patients. A cleaved isoform of VDBP, spot 873, is present at significantly reduced levels in the SF of oligoarticular patients at risk of disease extension, relative to other subgroups (p<0.05). Conversely total levels of vitamin D binding protein are elevated in plasma and ROC curves indicate an improved diagnostic sensitivity to detect patients at risk of disease extension, over both spot 873 and CRP levels. Sialysed forms of intact immunopurified VDBP were more prevalent in persistent oligoarticular patient synovial fluids.Conclusion:The data indicate that a subset of the synovial fluid proteome may be used to stratify patients to determine risk of disease extension. Reduced conversion of VDBP to a macrophage activation factor may represent a novel pathway contributing to increased risk of disease extension in JIA patients.