[Modification of the cytogenetic effects of irradiation by water with the reduced content of deuterium and heavy isotopes of oxygen].

The influence of light water with the reduced content of heavy stable isotopes of oxygen and hydrogen (deuterium) on the cytogenetic status of irradiated animals was investigated. In mice, hybrids of the first generation (CBA x C57B1) F1, the increase in the output (two-fold at the dose of 2 Gy) of aberrant mitoses in the cells of bone marrow and the decrease in the duration of the mitotic index of the first cellular cycle occurred under the influence of the two week maintenance before the irradiation on light water with ppm 35 obtained by the method of rectification as compared with the irradiated animals that were kept on the distilled water. It has been discovered that 24 h after irradiation the number of leukocytes in the group which consumed light water is lower than that in the animals that were contained on the distilled water. Moreover, the cellularity of the bone marrow in the group which consumed light water was higher than that in the animals that were contained on distilled water. The prolonged application of light water before irradiation (for 14 days) led to an increase in the sensitivity of the chromosomal apparatus of mice to γ-irradiation against the background of an increase in the mitotic activity of cells.

[Study of cytogenetic and cytotoxic effect of non-contact electrochemically-activated waters in the five organs of rats].

For the first time the multiorgan karyological analysis of five organs of rats was applied for the study of the cytogenetic and cytotoxic action of the four types of non-contact electrochemically activated water in the 30-days in vivo experiment. The effects of investigated waters were not detected in bone marrow polychromatic erythrocytes. "Anolyte" (ORP = -362 mV) did not have a negative effect on rats. "Catholyte-5" (ORP = +22 mV) and "Catholyte-25" (ORP = -60 mV) induced cytogenetic abnormalities in the bladder and fore stomach. The same catholytes and "Catholyte-40" (ORP = -10 mV) changed the proliferation indices: increased the mitotic index in the fore stomach epithelium and reduced the frequency of binucleated cells in the fore stomach, bladder and lungs. The increase in the rate of cells with cytogenetic abnormalities on the background of the promotion of mitotic activity can be considered as a manifestation of the negative effect, typical for catolytes, but the effect of each out of them has its own features.

[Effect of a mineral organic complex on mice radioresistance].

Experiments showed that drinking water supplemented with a complex of 12 microelements and organic acids stimulates body mass gain and strengthening of radioresistance in mice. Obviously, availability of water with the mineral and organic complex before and after irradiation was the factor in survival of a part of mice exposed to the absolutely lethal dose (7.6 Gy from gamma-quanta 60Co) and reduction of chromosomal aberrations rate in bone marrow cells in consequence of nonlethal (1 Gy) irradiation.

[Relationship of structural-functional (histological and cytological) parameters with cytogenetic and cytotoxic ones in the evaluation of the influence of environmental factors on the organism].

The paper gives an assessment of the association of structural-functional (histological and cytological), cytogenetic, and cytotoxic changes in the analysis of various exposures of the body during both experiments (oral acrylamide) and population examinations (impact of pulp-and-paper mill waste on the nasal and oral mucosae). The assessment of the association of the study parameters is shown to serve to more completely objectify the pattern of actuating factors.

[The cytogenetic status of children living in the vicinity of a pulp-and-paper mill].

To evaluate the cytogenetic and cytotoxic effects of a set of pollutions in the town of Koryazhma, the investigators made a complete karyological analysis (cytogenetic, apoptotic, and indirect proliferation parameters) of buccal and nasal epithelial exfoliative cells in two groups of old school age children living at various distances from a pulp-and-paper mill (PPM). The residential area that is adjacent to the PPM can be considered to be poor in the influence of genotoxic factors since there were 1.6- and 1.65-fold increases in cytogenetic disorders and cells with an atypically shaped nucleus, respectively, with a 1.57-fold reduction in the level of cell apoptosis. Karyological changes were revealed in the nasal mucosa, rather than in the buccal mucosa, which permitted one to recommend for the evaluation of the influence of environmental factors, the impact of ambient air pollution in particular, and to conduct cytogenetic studies on the cells of not only the buccal epithelium (that has been better studied), but also those of the nasal epithelium.

[Use of morphofunctional and cytogenetic studies to analyze the influence of environmental factors].

Long-term studies of 2 (cytohistology and genetic monitoring) laboratories of the Research Institute of Human Ecology and Environmental Hygiene, Russian Academy of Medical Sciences, to investigate the influence of environmental factors in the experiments made it possible to develop a noninvasive procedure for evaluating their cytological and cytogenetic impacts on man. A concurrent study of morphofunctional (histological, cytological) and cytogenetic parameters in both experimental and field trials can substantially extend and refine the interpretation of responses to environmental factors, which generates a need for using these parameters in hygienic and epidemiological studies.

Evaluation of mutagenic activity of dioxazid by the polyorgan micronuclear method in experiments on rats.

The mutagenic effect of antituberculous drug dioxazid was studied on rats receiving this preparation in a dose of 25 mg/kg (in conversion to dioxidine) via inhalation route for 3 months. The percentage of cells with micronuclei and the content of polychromatophilic erythrocytes among all bone marrow erythrocytes and percentage of cells with micronuclei, protrusions, and binucleated cells in the lungs and urinary bladder were evaluated. Dioxazid caused no changes in organs, except the increase in the percentage of binucleated cells in bladder epithelium, which attests to minor cytotoxic effect of the drug for this organ.

[Physicochemical properties of the microbial exopolysaccharide ethapolan synthesized on a mixture of growth substrates]. / Fiziko-khimicheskie svoistva mikrobnogo ékzopolisakharida étapolana, sintezirovannogo na smesi rostovykh substratov.

Some physicochemical properties of the microbial exopolysaccharide (EPS) ethapolan synthesized by Acinetobacter sp. 12S depended on whether the producer was grown on a mixture of ethanol and glucose or on single substrates. Irrespective of the carbon source in the nutrient medium, the contents of carbohydrates, pyruvic acid, uronic acids, and mineral components in the EPS remained unchanged. The EPS were also identical in their monosaccharide composition: the molar ratio of glucose, mannose, galactose, and rhamnose was 3:2:1:1. EPS with a higher proportion of fatty acids was synthesized during growth on the mixture of ethanol and glucose. Average molecular weight and the proportion of high-molecular (over two million) fractions were greater in ethapolan produced on the substrate mixture. In the presence of 0.1 M KCl, after transformation into the H+ form, and in the Cu(2+)-glycine system, solutions of these EPS showed higher viscosity than solutions of EPS synthesized on single substrates. The reasons for the improved rheological properties of the EPS produced on the substrate mixture are discussed.

Study of mutagenic activity of dioxidine by the polyorgan micronuclear method.

Antibacterial preparation dioxidine administered four times in doses of 10, 100, and 300 mg/kg increased the incidence of micronucleated cells in the bone marrow, lungs, and large intestine of mice. Bone marrow cells were most sensitive, while cells of the lungs and large intestine exhibited lower sensitivity to the cytogenetic effect of dioxidine.

[Intensification of the exopolysaccharide synthesis by Acinetobacter sp. on an ethanol-glucose mixture: aspects related to biochemistry and bioenergetics]. / Energeticheskie i biokhimicheskie aspekty intensifikatsii sinteza ékzopolisakharidov Acinetobacter sp. na smesi étanola i gliukozy.

The possibility of intensifying the synthesis of microbial exopolysaccharides (EPS) by a strain of Acinetobacter sp. grown on a mixture of two substrates nonequivalent in terms of bioenergetics (ethanol + glucose) was shown. Based on theoretical calculations of the energy requirements for biomass and EPS synthesis from the energy-deficient substrate (glucose), the supplementary concentration of the energy-excessive substrate (ethanol) was determined that prevents the loss of glucose carbon that occurs when glucose is oxidized to CO2 to obtain energy for the processes of constructive metabolism. This made it possible to increase the efficiency of conversion of the substrate carbon to EPS. The introduction of ethanol into glucose-containing medium at a molar ratio of 3.1:1 allowed the amount of the EPS synthesized to be increased 1.8- to 1.9-fold; their yield relative to biomass increased 1.4- to 1.7-fold, and the yield of EPS relative to the substrate consumed increased 1.5- to 2-fold as compared to growth of the producer on single substrates. These results form the basis for the development of new technologies for obtaining secondary metabolites of practical value with the use of mixed growth substrates.

[Intensification of synthesis of the exopolysaccharide ethapolan by Acinetobacter sp. 12S grown on a mixture of substrates]. / Intensifikatsiia sinteza ékzopolisakharida étapolana na smesi rostovykh substratov.

Enhanced synthesis of the exopolysaccharide (EPS) ethapolan by Acinetobacter sp. 12S was observed when the bacterium was grown on a mixture of two energetically nonequivalent substrates (ethanol and glucose) taken in a molar proportion of 3.1:1. The efficiency of carbon transformation into EPSs was maximum when sodium ions were absent in the medium, the concentration of nitrogen source was reduced to 0.3-0.45 g/l, and the inoculum was grown on ethanol. Such conditions provided an increase in the maximum specific growth rate and its attainment in earlier cultivation terms. Molasses as a substitution for glucose was inefficient. The activities of the key enzymes of C2-metabolism in Acinetobacter sp. 12S cells grown on the substrate mixture was 1.1 to 1.7 times lower than they were during growth on ethanol alone. The activity of isocitrate lyase in cells grown on the substrate mixture declined to an even greater extent (by 4 to 7 times), indicating that the role of the glyoxylate cycle in such cells is insignificant.

[Exopolysaccharide production and peculiarities of C6-metabolism in Acinetobacter sp. grown on carbohydrate substrates]. / Obrazovanie ékzopolisakharidov na uglevodnykh substratakh shtammom Acinetobacter sp. i osobennosti ego C6-metabolizma.

An Acinetobacter sp. strain grown on carbohydrate substrates (mono- and disaccharides, molasses, starch) was shown to synthesize exopolysaccharides (EPS). Glucose catabolism proved to proceed via the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways. Pyruvate entered the tricarboxylic acid cycle due to pyruvate dehydrogenase activity. Pyruvate carboxylation by pyruvate carboxylase was the anaplerotic reaction providing for the synthesis of intermediates for the constructive metabolism of Acinetobacter sp. grown on C6-substrates. The C6-metabolism in Acinetobacter sp. was limited by coenzyme A. Irrespective of the carbohydrate growth substrate (glucose, ethanol), the activities of the key enzymes of both C2- and C6-metabolism was high, except for the isocitrate lyase activity in glucose-grown bacteria. Isocitrate lyase activity was induced by C2-compounds (ethanol or acetate). After their addition to glucose-containing medium, both substrates were utilized simultaneously, and an increase was observed in the EPS synthesis, as well as in the EPS yield relative to biomass. The mechanisms responsible for enhancing the EPS synthesis in Acinetobacter sp. grown on a mixture of C2- and C6-substrates are discussed.