The changing of cell-free DNA properties of peripheral blood and TCR-mutant cell frequency in individuals exposed to ionizing radiation

Some properties of the cell-free DNA (cfDNA) of peripheral blood plasma were assessed in 153 employees of atomic industry enterprises. The contents of ribosomal repeat (rDNA) and its concentration in plasma increased in cfDNA of the group of persons in comparison with non-irradiated individuals. The contents of satellite III in cfDNA of donors and of irradiated persons do not differ and less than in DNA nucleus. The correlation between cumulative dose of radiation, contents of rDNA in cfDNA and the frequency of lymphocytes bearing mutations at T-cell receptor (TCR) locus was obtained. The definition of three indications in irradiated persons: the contents of ribosomal genes in cfDNA, TCR-mutant cell frequency and concentration of ribosomal genes in blood plasma--may be useful for revealing individuals in organism of which an intensive cell apoptosis takes place and there is an increased probability of carcinogenesis and of progress of disease of immune system.     

Role of changes in the transmembrane ion currents in pathological states of the body

Modern data of study of transmembrane ions currents (through the sodium-potassium- and calcium-channels) in the mechanism of pathological pain syndromes were reviewed. Tetrodotoxyn-resistant sodium currents, abnormal combinations of different types of sodium-channels during the inflammation, neuropathies (syndromes hyperalgesii and allodonii) and diabetic neuropathy analyzed. The role of pain sensitivity transmitters was demonstrated. Nerve Grow Factor plays the important role in the sodium-channels genes expression. Different types of transmembrane calcium currents participated in hyperalgesium and hypoalgesium analyzed. The summary mechanism of pain suggested as voltage-calcium-channels activation and transsynaptic NMDA receptors excitation that should be conductive the neurons hyperexcitation and force of synaptic transmission.     

Endoplasmic reticulum and mitochondria as elements of mechanism of intracellular signaling in neurons

The temporal and spatial characteristics of a transitory increase in free Ca2+ ("calcium signals") concentration were determined in various types of the mice and rat neurones. Intracellular structures: endoplasmatic reticulum and mitochondria, were shown to play a major part in formation of these signals, the structures being able to absorb the Ca2+ ions from cytosol and release them back. The contribution of these processes proves rather varying depending on internal organisation and functional assignment of a neurone.     

Isolation and effects of inducing factors secreted by the lens epithelium cells

Our previous studies showed that, unlike tissue extracts, the cells of living organs secrete substances capable of inducing the same organ rudiments in the early gastrula ectoderm (EGE). In this work, the molecular nature of these substances was studied. The porcine lens epithelium was chosen for the initial analysis. When cultivated, this epithelium secreted a mixture of proteins, which were separated by gel-filtration. Both the total protein mixture and its individual fractions were tested for their inducing capacity using the early gastrula ectoderm of Rana temporaria. Unexpected results were obtained, which indicated that (a) the mixture of native proteins secreted by lens epithelium has a selective inducing capacity differing from those of individual fractions isolated from this mixture and (b) each fraction has a specific effect, but all of them cause the induction of neural tissue or sensory organs. These results (obtained for the first time) suggest that the inducing capacity of individual protein fractions is wider than that of the total protein mixture secreted by lens epithelium. This fact raises a question concerning the relationships between the mechanisms underlying the corresponding inducing effects.     

Bile Salts Modulate the Mucin-Activated Type VI Secretion System of Pandemic Vibrio cholerae

The causative agent of cholera, Vibrio cholerae, regulates its diverse virulence factors to thrive in the human small intestine and environmental reservoirs. Among this pathogen’s arsenal of virulence factors is the tightly regulated type VI secretion system (T6SS). This system acts as an inverted bacteriophage to inject toxins into competing bacteria and eukaryotic phagocytes. V. cholerae strains responsible for the current 7^th pandemic activate their T6SS within the host. We established that T6SS-mediated competition occurs upon T6SS activation in the infant mouse, and that this system is functional under anaerobic conditions. When investigating the intestinal host factors mucins (a glycoprotein component of mucus) and bile for potential regulatory roles in controlling the T6SS, we discovered that once mucins activate the T6SS, bile acids can further modulate T6SS activity. Microbiota modify bile acids to inhibit T6SS-mediated killing of commensal bacteria. This interplay is a novel interaction between commensal bacteria, host factors, and the V. cholerae T6SS, showing an active host role in infection.     

The Hydrogenase Chip: a tiling oligonucleotide DNA microarray technique for characterizing hydrogen-producing and -consuming microbes in microbial communities

We developed a broad-ranging method for identifying key hydrogen-producing and consuming microorganisms through analysis of hydrogenase gene content and expression in complex anaerobic microbial communities. The method is based on a tiling hydrogenase gene oligonucleotide DNA microarray (Hydrogenase Chip), which implements a high number of probes per gene by tiling probe sequences across genes of interest at 1.67 × –2 × coverage. This design favors the avoidance of false positive gene identification in samples of DNA or RNA extracted from complex microbial communities. We applied this technique to interrogate interspecies hydrogen transfer in complex communities in (i) lab-scale reductive dehalogenating microcosms enabling us to delineate key H₂-consuming microorganisms, and (ii) hydrogen-generating microbial mats where we found evidence for significant H₂ production by cyanobacteria. Independent quantitative PCR analysis on selected hydrogenase genes showed that this Hydrogenase Chip technique is semiquantitative. We also determined that as microbial community complexity increases, specificity must be traded for sensitivity in analyzing data from tiling DNA microarrays.     

Use of a heptane-isopropanol system for extraction of primary lipid peroxidation products

Products of different lipids oxidation were studied for the peculiarities of their distribution in the extracting system heptane--isopropanol widely used in spectrophotometric determination of primary products of peroxide oxidation of lipids. It is shown that hydroperoxides of phospholipids and their reduction products almost completely transfer to the alcohol phase while hydroperoxides of triacetin and cholesterol esters are 70-85% extracted by heptane. Thus, it is necessary to analyze the alcohol phase when using the systems heptane-isopropanol to determine the content of primary products of lipid peroxide oxidation in those tissues, where phospholipids are the basic oxidation substrates.