Evaluating the efficacy of stool sample on Xpert MTB/RIF Ultra and its comparison with other sample types by meta-analysis for TB diagnostics

European Journal of Clinical Microbiology & Infectious Diseases - Precise and timely detection of tuberculosis (TB) is crucial to reduce transmission. This study aims to assess the accuracy of...     

Synthesis and Antitubercular Activity Evaluation of Novel Unsymmetrical Cyclohexane‐1,2‐diamine Derivatives

A library of unsymmetrical cyclohexane‐1,2‐diamine derivatives were synthesized and evaluated for their activity against Mycobacterium tuberculosis H37Rv in vitro. Out of the 46 compounds synthesized, eight compounds ( 11h , 13a , 13e , 13f , 14a , 14c , 14d , and 15d ) were found to be active at or below 6.25 µM concentration, with negligible toxicity to human red blood cells at a concentration much higher than the MIC₉₉. Compound 13a was the best active compound showing inhibition at 3.125–6.25 µM, and was found to be non‐hemolytic up to 500 µg/mL concentration.     

Ceramide transfer protein function is essential for normal oxidative stress response and lifespan

Ceramide transfer protein (CERT) transfers ceramide from the endoplasmic reticulum to the Golgi complex, a process critical in synthesis and maintenance of normal levels of sphingolipids in mammalian cells. However, how its function is integrated into development and physiology of the animal is less clear. Here, we report the in vivo consequences of loss of functional CERT protein. We generated Drosophila melanogaster mutant flies lacking a functional CERT (Dcert) protein using chemical mutagenesis and a Western blot-based genetic screen. The mutant flies die early between days 10 and 30, whereas controls lived between 75 and 90 days. They display >70% decrease in ceramide phosphoethanolamine (the sphingomyelin analog in Drosophila) and ceramide. These changes resulted in increased plasma membrane fluidity that renders them susceptible to reactive oxygen species and results in enhanced oxidative damage to cellular proteins. Consequently, the flies showed reduced thermal tolerance that was exacerbated with aging and metabolic compromise such as decreasing ATP and increasing glucose levels, reminiscent of premature aging. Our studies demonstrate that maintenance of physiological levels of ceramide phosphoethanolamine by CERT in vivo is required to prevent oxidative damages to cellular components that are critical for viability and normal lifespan of the animal.     

2010 Society for Neuro-Oncology Annual Meeting: a report of selected studies

A number of important studies were presented at the Society for Neuro-Oncology annual meeting in Montréal, Canada, on 18-21 November 2010. Cediranib as monotherapy or in combination with lomustine did not show increased efficacy when compared with lomustine alone in patients with recurrent glioblastoma (GBM). Addition of temozolomide (TMZ) or irinotecan (CPT) to bevacizumab (BEV) in patients with recurrent GBM was well tolerated, with similar efficacy to BEV alone. The addition of BEV to radiation and TMZ in newly diagnosed GBM improved progression-free survival but did not improve overall survival. TMZ alone may be a reasonable approach in elderly GBM patients with poor performance status. Two Phase II trials with sunitinib and vatalanib showed a hint of activity in patients with recurrent or progressive meningiomas.     

Formulation optimization of double emulsification method for preparation of enzyme-loaded Eudragit S100 microspheres

The present study aimed to develop an oral sustained release microparticulate system for acid labile enzyme-Serratiopeptidase. A 3(2) full factorial experiment was designed to study the effects of the external aqueous phase volume and stabilizer (Tween 80) concentration on the entrapment and size of Eudragit S100 microspheres prepared by a modified double emulsion solvent evaporation technique. The results of analysis of variance tests for both effects indicated that the test is significant. The effect of external aqueous phase volume was found to be higher on the entrapment efficiency of microspheres (SSY(1) = 1362.63; SSY(2) = 250.13), whereas Tween 80 produced a significant effect on size of microspheres (SSY(1) = 944.01; SSY(2) = 737.26). Scanning electron microscopy of microspheres demonstrated smooth surface spherical particles. The effect of formulation variables on the integrity of enzyme was confirmed by in vitro proteolytic activity. Microspheres having maximum drug encapsulation (81.32 ± 3.97) released 4-5% enzyme at pH 1.2 in 2 h. The release of enzyme from microspheres followed Higuchi kinetics (R(2) = 0.987). In phosphate buffer, microspheres showed an initial burst release of 25.65 ± 2.35% in 1 h with an additional 62.96 ± 4.09% release in the next 5 h. Thus, formulation optimization represents an economical approach for successful preparation of Eudragit S100 microspheres involving fewest numbers of experiments.     

Ultrastructural Morphologic Changes in Mycobacterial Biofilm in Different Extreme Condition

The aim of this study was to investigate the morphologic and ultrastructural features of biofilms of slow and fast-growing mycobacteria in different stress conditions, presence and absence of oleic acid albumin dextrose catalase (OADC) enrichment and at different temperatures: 30, 37 and 42?°C. Four hundred mycobacterial isolates were taken. The biomass of each biofilm was quantified using a modified microtiter plate assay method. Isolates were divided into those that formed fully established biofilms, moderately attached biofilms and weakly adherent biofilms by comparison with a known biofilm-forming strain. The large quantity of biofilm was produced by Mycobacterium smegmatis at temperature 37 and 42?°C as compared to 30?°C. Mycobacterium fortuitum and M. avium developed large amount of biofilm at 30?°C as compared to 37 and 42?°C. Mycobacterium tuberculosis developed strong biofilm at 37?°C and no biofilm at 30 and 42?°C in Sauton’s media. The selected non-tuberculous mycobacteria and H37Rv developed strong biofilm in the presence of OADC enrichment in Sauton’s medium. Microscopic examination of biofilms by scanning electron microscopy revealed that poorly adherent biofilm formers failed to colonize the entire surface of the microtiter well. While moderately adherent biofilm formers grew in uniform monolayers but failed to develop a mature three-dimensional structure. SEM analysis of an isolate representative of the group formed fully established biofilms with a textured, multi-layered, three-dimensional structure.