The virulence and colicinogenicity of pathogenic Escherichia isolated from water and human beings

An analysis of virulence and colicinogenicity of 180 cultures of pathogenic Escherichia of different origin has shown that the expressed characters occurred in 40 +/- 49% of strains isolated from people and 28.7 +/- 5.1% of strains isolated from water. The dependence of the studied properties on serogroups of the agents is established. These characters are more often inherent in representatives of the dominating serogroups, which may be a reason of their selective advantage in circulation among people and in water.     

A cellular test system expressing hERG K+ channels for assaying drug cardiotoxicity: Elaboration and analysis

Many drugs are cardiotoxic because they inhibit hERG K⁺ channels, thus prolonging the repolarization phase of the cardiomyocyte action potential giving rise to cardiac arrhythmias. Early detection of inhibiting effects of candidate drugs on the activity of K⁺ channels in cardiomyocytes is one of the main challenges in preclinical drug screening. The aim of this study was to obtain a cell line expressing recombinant hERG channels at a stable and reproducible level as a prerequisite to its further application as a test system.     

The determination of Escherichia virulence on nutrient media]

The virulence of 250 pathogenic Escherichia strains secreted from humans and from various environmental objects has been studied on nutrient media with stains, ram erythrocytes and in hemagglutination reactions. The highest percentage of strain virulence is revealed when using crystal violet and in the blood agar (44.0 and 27.2%, respectively), evidently, due to nonspecific reactions. The medium with congo red showed a positive result in 20.3 + 3.1%, and the d-mannose-resistant hemagglutination reaction--in 16.5 + 2.3% cases. In practice it is recommended to use several methods which enable estimating correctly the risk to infect humans and to conduct timely preventive measures.     

Exon-intron structure of the <Emphasis Type="Italic">Xist</Emphasis> gene in elephant,armadillo, and the ancestor of placental mammals

The Xist gene belongs to the class of long noncoding regulatory RNA genes which play a key role in the process of inactivation of one of the X chromosomes in females of placental mammals. Based on inter-specific comparative sequence analysis performed using a set of bioinformatic programs and approaches, the exon-intron gene structure was first described in two species, elephant and armadillo, belonging to the most primitive placental mammal groups, Afrotheria and Xenarthra. Using multiple sequence alignment of the species representing all main groups of placental mammals (12 species), consensus sequence of the ancestral gene was reconstructed. In the gene structure four evolutionary conserved regions with the identity level of 90% and the sizes of more than 100 bp were identified. Substantial contribution of transposable elements to the gene origin, as well as mosaic evolution of certain elements of the Xist locus was demonstrated. It is likely that the ancestral gene consisted of ten exons and was formed before the radiation of placental mammals, in the period from 140 to 105 Myr ago.