Effect of natural radioprotector carnosine on histamine-diamine oxidase system of rat's myocardium after action of various extreme factors

The unbalance in system histamine-diaminooxydase in myocardium of rats subjected to various stress actions (intensive cold influence, hyperthermia and hypoxia) was found. The preventive application of a natural radioprotector carnosine prevented apparent changes, that gives the basis to assume about carnosine ability to enlarge a nonspecific resistance of an organism.     

Neurochemical characteristics of the ventromedial hypothalamus and anti-aversive effects of anxiolytic agents in various anxiety models]

Neurochemical analysis using anxiosedative and anxioselective agents injected into the hypothalamus revealed that antiaversive action of camprione is only realised under conditions of domineering fear motivation whereas that of chlordiazepoxide, phenibut, indoter may also be realised under conditions of negative stressful zoo-social impacts mediated by serotonin.     

Structural Changes and Cellular Localization of Resuscitation-Promoting Factor in Environmental Isolates of Micrococcus luteus

Dormancy among nonsporulating actinobacteria is now a widely accepted phenomenon. In Micrococcus luteus, the resuscitation of dormant cells is caused by a small secreted protein (resuscitation-promoting factor, or Rpf) that is found in “spent culture medium.” Rpf is encoded by a single essential gene in M. luteus. Homologs of Rpf are widespread among the high G + C Gram-positive bacteria, including mycobacteria and streptomycetes, and most organisms make several functionally redundant proteins. M. luteus Rpf comprises a lysozyme-like domain that is necessary and sufficient for activity connected through a short linker region to a LysM motif, which is present in a number of cell-wall-associated enzymes. Muralytic activity is responsible for resuscitation. In this report, we characterized a number of environmental isolates of M. luteus, including several recovered from amber. There was substantial variation in the predicted rpf gene product. While the lysozyme-like and LysM domains showed little variation, the linker region was elongated from ten amino acid residues in the laboratory strains to as many as 120 residues in one isolate. The genes encoding these Rpf proteins have been characterized, and a possible role for the Rpf linker in environmental adaptation is proposed. The environmental isolates show enhanced resistance to lysozyme as compared with the laboratory strains and this correlates with increased peptidoglycan acetylation. In strains that make a protein with an elongated linker, Rpf was bound to the cell wall, rather than being released to the growth medium, as occurs in reference strains. This rpf gene was introduced into a lysozyme-sensitive reference strain. Both rpf genes were expressed in transformants which showed a slight but statistically significant increase in lysozyme resistance.     

The role of glutathione in natural and modified radioresistance of yeast cells

A study was made of the dependence of different natural and modified radioresistance upon glutathione content of yeast cells (Saccharomyces cerevisiae and Pichia guilliermondii). It was shown that glutathione was only involved in the formation of natural radioresistance in Saccharomyces cerevisiae cells. It was also shown that the increase in the radioresistance of yeast cells under the effect of 2-amino-2-thiazoline was accompanied by the increase in the level of total glutathione in them.     

Mechanisms in the regulation of the level of lipid radiosensitizing agents in yeast cells with different types of radioresistance

Factors controlling the lipid sensitizers level: the composition of fatty lipid acids, their antioxidative activity, the enzyme systems reactivity (superoxide dismutase, catalase, glutatione peroxidase and glutatione reductase) have been studied in yeast cells with different radioresistance. In six lines of yeast cells the leading role of superoxide dismutase--one of the regulators of lipid peroxidation have been demonstrated in cells native radioresistance formation.     

Nitroxyl compounds in bacteria: Search for functions

A method was developed for incorporation of two deuterium atoms into the reactive group of a new type of nitroxyl compounds from Micrococcus luteus (a lysodektose which can be transformed into a long-living free radical). This compound was found to persist in the cells treated with gentamycin and chloramphenicol, while treatment with gramicidin C, ampicillin, benzyl viologen, furadonin, and mercury chloride resulted in a drastic decrease of its intracellular content. Cultivation of M. luteus in a medium with EDTA resulted in accumulation of much higher amounts of lysodektose (up to 300%), and this phenomenon is interpreted as an indication of the possible siderophore function of the compound. Since the M. luteus genome was recently sequenced, this may help to understand the fate and role of lysodektose in bacterial metabolism.     

Osteogenic differentiation of mouse bone marrow stromal cells on fibroin microcarriers

We investigated the proliferation and osteogenic differentiation of mesenchymal stem cells cultured on fibroin microcarriers. Effective cell proliferation on the surface of the microcarriers, determined by the large surface area, and the contribution of microcarrier mineralization to the stimulation of the osteogenic differentiation of mesenchymal stem cells was revealed.     

Effect of 2-amino-2-thiazoline on the level of lipid peroxidation products in different yeast species

The influence of 2-amino-2-thiazoline on lipid peroxidation in yeasts Saccharomyces cerevisiae and Pichia guilliermondii has been studied in vivo and in vitro. In the case the radioresistance of diploid yeasts-saccharomycetes is changed the radioprotector can produce a direct effect on lipid peroxidation. Different radioprotective efficiency of the preparation with regard to different strains of one and the same yeast culture is explained by its different influence on the content of endogenous radioprotective factors exerting a control over the accretion of lipid peroxidation products. The observed differences in the lag-periods of peroxidation in Saccharomyces cerevisiae and Pichia guilliermondii correspond to the level of their natural antioxidant activity of lipids.