A model of blood flow in the mesenteric arterial system

Background  

There are some early clinical indicators of cardiac ischemia, most notably a change in a person's electrocardiogram. Less well understood, but potentially just as dangerous, is ischemia that develops in the gastrointestinal system. Such ischemia is difficult to diagnose without angiography (an invasive and time-consuming procedure) mainly due to the highly unspecific nature of the disease.     

Metagenomic analysis of Surti buffalo (Bubalus bubalis) rumen: a preliminary study

The complex microbiome of the rumen functions as an effective system for the conversion of plant cell wall biomass to microbial proteins, short chain fatty acids and gases. In this study, metagenomic approaches were used to study the microbial populations and metabolic potential of the microbial community. DNA was extracted from Surti Buffalo rumen samples (four treatments diet) and sequenced separately using a 454 GS FLX Titanium system. We used comparative metagenomics to examine metabolic potential and phylogenetic composition from pyrosequence data generated in four samples, considering phylogenetic composition and metabolic potentials in the rumen may remarkably be different with respect to nutrient utilization. Assignment of metagenomic sequences to SEED categories of the Metagenome Rapid Annotation using Subsystem Technology (MG-RAST) server revealed a genetic profile characteristic of fermentation of carbohydrates in a high roughage diet. The distribution of phylotypes and environmental gene tags (EGTs) detected within each rumen sample were dominated by Bacteroidetes/Chlorobi, Firmicutes and Proteobacteria in all the samples. The results of this study could help to determine the role of rumen microbes and their enzymes in plant polysaccharide breakdown is fundamental to understanding digestion and maximising productivity in ruminant animals.     

Diversity pattern in Sesamum mutants selected for a semi-arid cropping system

Summary Due to the complex requirements of moisture stress, substantial genetic diversity with a wide array of character combinations and effective simultaneous selection for several variables is necessary for improving the productivity and adaptation of a component crop in order for it to fit into a cropping system under semi-arid tropical conditions. Sesamum indicum L. is grown in Venezuela after rice/sorghum/or maize under such conditions. A mutation breeding program was undertaken using six locally adapted varieties to develop genotypes suitable for the above system. The diversity pattern for nine variables was assessed by multivariate analysis in 301 M₄ progenies. Analysis of the characteristic roots and principal components in three methods of selection, i.e., M₂ bulks (A), individual plant selection throughout (B), and selection in M₃ for single variable (C), revealed differences in the pattern of variation between varieties, selection methods, and varieties x methods interactions. Method B was superior to the others and gave 17 of the 21 best M₅ progenies. Piritu and CF varieties yielded the most productive progenies in M₅ and M₆. Diversity was large and selection was effective for such developmental traits as earliness and synchrony, combined with multiple disease resistance, which could be related to their importance by multivariate analyses. Considerable differences in the variety of character combinations among the high yielding. M₅ progenies of CF and Piritu suggested possible further yield improvement. The superior response of Piritu and CF over other varieties in yield and adaptation was due to major changes in plant type and character associations. Multilocation testing of M₅ generations revealed that the mutant progenies had a 40%–100% yield superiority over the parents; this was combined with earliness, synchrony, and multiple disease resistance, and was confirmed in the M₆ generation grown on a commercial scale. This study showed that multivariate analysis is an effective tool for assessing diversity patterns, choice of appropriate variety, and selection methodology in order to make rapid progress in meeting the complex requirements of semi-arid cropping systems.Project supported by the International Atomic Energy Agency, Vienna, Austria     

Campylobacter pyloridis degrades mucin and undermines gastric mucosal integrity

The role of Campylobacter pyloridis, a spiral bacteria associated with gastritis and peptic ulcers in weakening the mucus component of gastric mucosal barrier was investigated. The colonies of bacteria, cultured from antral mucosal biopsies of patients undergoing gastroscopy, were washed with saline, passed through sterilization filter and the filtrate was examined for protease and glycosylhydrolase activities. The obtained results revealed that the filtrate exhibited a strong proteolytic activity not only towards the typical protein substrates such as albumin but also towards gastric mucin. Optimum enzymatic activity for degradation of mucin was attained at pH 7.0 and the protease activity was found in a low m.w. (less than 50K) protein fraction. The filtrate showed little glycosylhydrolase activity and did not cause the hydrolysis of mucin carbohydrates. The data suggest that C pyloridis infection weakens the gastric mucosal defense by causing proteolytic degradation of mucin component of the protective mucus layer.     

Transcriptomic response to differentiation induction

Background  

Microarrays used for gene expression studies yield large amounts of data. The processing of such data typically leads to lists of differentially-regulated genes. A common terminal data analysis step is to map pathways of potentially interrelated genes.     

Lipid composition of the secretion from human bronchial explant culture

In this study, we identified and quantitated the lipid components in the secretions of human bronchial explants cultured in a serum-free medium over a period of 50 days. Total lipids represented 6% of the dry material. This amount is considerably lower than that reported for 'normal' human sputum and suggests that the latter is contaminated by serum transudates, alveolar secretions, and microorganisms. Such serum-free culture systems are highly suitable to study cell physiology as it relates to human disease.