[Physicochemical, catalytic, and regulatory properties of malate dehydrogenase from Rhodovulum steppense bacteria, strain A-20s].

The physicochemical, regulatory, and kinetic properties of malate dehydrogenase (EC 1.1.1.37) from haloalkaliphilic purple nonsulfur Rhodovulum steppense bacteria, strain A-20s, were studied. The malate dehydrogenase (MDH) preparation with a specific activity of 0.775 ± 0.113 U/mg protein was obtained in an electrophoretically homogeneous state using multistep purification. Using homogenous preparations, the molecular weight and the Michaelis constant of the enzyme were determined; the effects of metal ions, the temperature effect, and the thermal stability of the MDH were studied. The dimer structure of the enzyme was demonstrated by DS-Na-electrophoresis.

[Mechanism of malate dehydrogenase isoform formation in Sphaerotilus natans D-507 under different cultivation conditions].

Electrophoretically homogenous preparations of malate dehydrogenase (MDH) isoforms of the bacteria Sphaerotilus natans D-507 with specific activity 7.46 U/mg and 5.74 U/mg with respect to protein concentration have been obtained. The dimeric isoform of the enzyme was shown to function under organotrophic growth conditions, whereas the tetrameric isoform was induced under mixotrophic cultivation conditions. PCR-analysis revealed a single gene encoding the malate dehydrogenase molecule. The topography of the MDH isoform surface was studied by atomic-force microscopy, and a 3D-structure of the enzyme was obtained. Spectraphotometric analysis data allowed us to suggest that stabilization of the tetrameric form of MDH is due to additional bounds implicated in the quaternary structure formation.

[Structural-functional transformation of the malate dehydrogenase system of the bacterium Sphaerotilus sp. strain D-507 depending on nutritional mode].

High-purity preparations of malate dehydrogenase (EC 1.1.1.37) were obtained by multistage purification from the bacterium Sphaerotilus sp. strain D-507 growing under different conditions. Under organotrophic conditions, the enzyme was dimeric; under mixotrophic conditions, dimeric and trimeric. On the basis of studied properties of the enzyme preparations, data on the activity of enzymes of the glyoxylate and tricarboxylic-acid cycles, and analysis of published data, it can be concluded that malate dehydrogenase isoforms are implicated in the adaptive response of bacteria to changing culturing conditions.

[An experimental study of the toxicological characteristics of ships' wastes for the hygienic validation of technological layouts of new water-protection equipment]. / Eksperimental'noe izuchenie toksikologicheskikh kharakteristik sudovykh stochnykh vod dlia gigienicheskogo obosnovaniia tekhnologicheskikh skhem novogo vodookhrannogo oborudovaniia.

The effect of waste waters, as well as of waste waters, that had undergone physicochemical treatment and disinfection, on the organism of experimental animals was investigated. The influence of purified and nonpurified sewage on the morphological structure of organs (liver, brain, kidney, myocardium), on the biochemical processes in experimental animals' tissues, on the immune reactivity of experimental animals was determined. The improvement of the morphological structures of the organs under study, of certain biochemical indices and bioimmunological reactivity of animals under peroral and dermal exposure to the purified waste waters gives the grounds for the conclusion on the biological safety and effective detoxication of waste waters which have undergone purification with the use of aluminum-containing coagulant of the aluminum oxichloride type, and which have been disinfected by ultraviolet irradiation.

[Hygienic evaluation of the effectiveness of using aluminum oxychloride for purification of ships' waste water]. / Gigienicheskaia otsenka éffektivnosti primeneniia oksikhloridov aliuminiia dlia ochistki sudovykh stochnykh vod.

Treatment of multicomponent composition ship waste waters by an aluminum-containing waste is substantiated from the hygienic point of view both in laboratory and field studies. The tested principle of treatment provides deep purification of liquid wastes according to the following indicators; particulate matter--95.3%; BCO5--90.0%; oil products--99.5%; cadmium--70.3%; iron--30.0%; phenol--48.1%; SSAS--37.5%. The effectiveness of coagulation of the combined sewage independent of quantitative ratios of bilgeway and waste waters has been confirmed with the help of regression-correlative analysis, which alongside the use of aluminum oxychlorides at the functioning installations of sewage purification and disinfection testify to the possibility of forming of principally new and effective samples of compact ship water protective equipment.

[Change in the structure of fibroblast chromatin in a patient with Down's disease and his mother]. / Izmenenie struktury khromatina fibroblastov u bol'nogo bolezn'iu Dauna i ego materi.

A clear-cut difference between chromatin melting curves of cells from the patient with Down's disease and his mother and ones from healthy individuals and the proband's father was shown by fluorescence microscopy and acridine orange staining on human fibroblasts incubated in autologous serum. These data suggest the presence of an obvious genetic correlation between phenotypically healthy mother and her sick child. The identity of the chromatin structure of the patients detected both on lymphocytes and other type of cells, human fibroblasts, allows a suggestion that the phenomenon of the altered chromatin structure is typical generally of the given individual's tissues. Certain changes in the cell chromatin structure are mediated by the effect of autologous serum.

[Variability of the heterochromatic regions of human chromosomes 1, 9, 16, and Y]. / Variabel'nost' geterokhromaticheskikh raionov khromosom 1, 9, 16, i Y u cheloveka.

The variability of heterochromatic regions on chromosomes 1, 9, 16 and Y has been studied in a group of unrelated subjects (50 boys and 50 girls) using quantitative methods. Analysis of intercellular (with one subject) variability of chromosome C-segments lengths has shown that their absolute lengths vary considerably with the cell sample examined, while the relative lengths (a part of the total length of C-segment of the chromosomes being studied) are more stable. The relative lengths may be helpful in individual characteristics, reproducible in repeated analysis, which may be used in zygosity testing in twins, family analysis, etc. Absolute lengths, however, may be successfully used in population studies, as the difference between the cell samples peculiarities on which the C-segment length is based in particular karyotypes, is obliterated. Comparative analysis of mean lengths and variability of C-segments on chromosomes 1, 9, 16 in the groups of boys and girls has revealed no differences between the sexes. The mean lengths and the standard deviations of C-segments' lengths on chromosomes 1, 9, 16 and Y obtained in this study are 1.26 +/- 0.23; 1.13 +/- 0.20; 0.85 +/- 0.14; 1.13 +/- 0.21 mcm respectively. Identical data on both sexes, as well as the normal distribution of C-segments' lengths confirm the idea that the length of the C-segment is a neutral characteristic in normal population.

The quantitative analysis of polymorphism on human chromosomes 1, 9, 16, and Y. II. Comparison of the C segments in male and female individuals (group characteristics).

Comparative analysis of the polymorphism of C segments on chromosomes 1, 9, 16, and Y was conducted in 50 normal boys and 50 normal girls. Quantitative methods revealed that the mean lengths of C segments, their variability, and their distribution on the chromosomes mentioned are quite identical in the two groups. Methodological problems related to the study of chromosome polymorphism are discussed.

The quantitative analysis of polymorphism on human chromosomes 1, 9, 16, and Y. I. Description of individual karyotypes.

This study was made to establish a stable quantitative characteristic of C segments on chromosomes 1, 9, 16, and Y in an individual karyotype that was reproducible in successive experiments. The C segment of these chromosomes were measured in successive cultures of cells from three males and the C segments of chromosomes 1, 9, and 16 in cells from three pairs of female monozygotic twins were measured. The results show that the absolute lengths of C segments tend to vary considerably with the cell samples analyzed, while the relative length, i.e., the length of a single C segment as a percentage of the total length of all C segments of the chromosomes being studied, is more stable and can be used for individual characteristics.