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Biomedical subjects

A S Belokhvostov

Publications and source records attributed to A S Belokhvostov.

At least 19 recordsLinked to original sources
PubMed2003

[The methodological specificity of PCR-test of gene p53 in plasma and blood cell DNA of oncological patients].

The evaluation of mutations in the p53 gene is of a big value for the laboratory diagnostics in oncology. The p53 gene was analyzed, within the present case study, in blood plasma, in which tumor-origin DNAs were detected, as well as in blood cells and in tumor tissue. Optimal conditions were defined for polymerase chain reaction (PCR) with primers. The adequacy of the conditions selected for PCR and for SSCP-electrophoresis, when used in the analysis of mutations in exons 5-8, gene p53, was shown by the method of direct sequencing. The first results on revealing the frequency of gene-p53 mutations were obtained for some of the oncology diseases in the studied population.

Blood Cells↗
PubMed2001

[Molecular genetic aspects of the antineoplastic effect of gluthoxim].

Gluthoxim--bis(g-L-gluthamyl)-L-cystenyl-bis-glycin disodium salt (C20H32O16N6S2)--is an analog of oxidized gluthation with a stable disulfide bond. It is a drug of a new class of thiopoetins which regulate thiol disulfide metabolism. Gluthoxim is used as a support substance in chemotherapy of cancer. The present investigation deals with feasibility of gluthoxim-induced apoptosis in tumor cell cultures, including human myeloleukema cells HL60 which lack protein p53 gene, so crucial for apoptosis. Also, gluthoxim effect was studied with respect to transformed murine fibroblasts C8 and A4, carrying the plasmide structure with Ras and E1A genes which boost Ras-gene expression. This in turn makes fibroblasts ready to start apoptosis. Gluthoxim induction of cell death was demonstrated in both cell lines; however, apoptosis in cells C8 (with intact gene p53) was much more pronounced than in cells A4 without this gene. It is suggested that apoptosis can be triggered by both imbalance of redox potential typical of tumor cells, induction of p53 synthesis and an impact on the phosphoproteinase cascade of Ras-signal pathway.

Animals↗
PubMed1998

[The potentials of molecular genetic diagnosis in military medicine (a review of the literature)].

The practical importance of the main genetic infringements in diagnostics of a wide circle of illnesses, including cardiology, nephrology, and oncology. Methods used. The exclusive effectiveness of application of the polymerasic chain reaction in the purposes of diagnostic. Expediency of application of the molecular-genetic methods for radiating, chemical and extreme effects evaluation.

Communicable Diseases↗
PubMed1995

[Methods for DNA diagnosis in military medicine].

The article makes a review of achievements in the sphere of biotechnology and genetic engineering as far as military medicine is concerned. A special attention is drawn on diagnostic capacities of molecular genetic methods which analyse DNA and RNA objects. Principles of modern diagnostical methods are described which are based on molecular hybridization of nucleic acids with a use of specific DNA probes or polymerize chain reaction (PCR). The advantages of the latter are shown in the comparison with immunochemical methods. Peculiarities of new quantitative PCR modifications are studied. The article contains data concerning the use of DNA probes and PCR for estimation of radiation injuries and during formation of maximal tolerance level of physical and chemical influence.

Base Sequence↗
PubMed1992

Extracellular DNA level in the blood of irradiated rats.

There is high-molecular DNA in the blood of unirradiated rats which moves as a single fraction during electrophoresis in 0.5% agarose. At short times (2-5 h) after gamma-irradiation at doses from 1 to 100 Gy a low-molecular species of DNA appears (about 180 nucleotide pairs), the amount of which is directly proportional to exposure dose at 5 h after exposure. It has been established by Southern hybridization that the low-molecular DNA has few nucleotide sequences common with those of the high-molecular DNA, but it shows homologously to genomic sequences.

Animals↗
PubMed1992

[Contents of extracellular DNA in blood of irradiated rats].

Intact rat plasma contains high-molecular DNA which moves as a single fraction in 0.5% agarose electrophoresis. As early as 2-5 hours after gamma-irradiation in a dose of 1-100 Gy there appears low-molecular DNA (about 180 nucleotide pairs), the amount of which directly correlates with the irradiation dose 5 hours after the exposure. Blot-hybridization showed that low-molecular DNA has no common nucleotide sequences with high-molecular DNA, though has sites similar to genome repeat sequences.

Animals↗
PubMed1991

[Detection of the determinants of tetracycline A, B and C resistance in Shigella and Salmonella using DNA probes].

Genetic determinants of tetracycline resistance of classes A, B and C were detected with DNA probes labeled with radioactive phosphorus (32P) in Shigella (44 strains) and Salmonella (50 strains). It was shown that in the Shigella strains the frequency of the Tet A gene amounted to 66 per cent, the frequency of the Tet B gene was equal to 84 per cent, the frequency of their combination was equal to 50 per cent and the frequency of the Tet C gene was nil. In the Salmonella strains the frequency of the Tet A, Tet B and Tet C genes was equal to 0.100 and 20 per cent, respectively, and that of their combination amounted to 20%. Possible use of the DNA probes in epidemiological analysis of outbreaks of Shigella and Salmonella infections is suggested.

DNA Probes↗
PubMed1985

[3H-thymidine incorporation into the DNA of the nucleic factor in the ascitic fluid of Ehrlich cancer].

After intraperitoneal administration of 1.85 MBq 3H-thymidine to mice with Ehrlich ascites tumours the maximal radioactivity of nucleic factor DNA of ascitic fluid was observed when the isotope had been injected 5-6 days before extraction of ascitic fluid (4-5.10(5) cpm/mg). The maximal radioactivity of DNA of tumour cells themselves was registered when 3H-thymidine was administered 2 days prior to tumour ascites extraction (5.2.10(5) cpm/mg). The administration of even 37 MBq 3H-thymidine 1.5 h before the ascitic fluid extraction from the Ehrlich ascites tumours did not result in the incorporation of this radioactive precursor into nucleic factor DNA. The results obtained show that there is an interval (several days) between the nucleic factor DNA synthesis and its secretion.

Animals↗
PubMed1984

[Nonprecipitability of the nucleic factor in the ultracentrifugation of tumor ascitic fluid].

Samples of cell-free ascitic liquid of mice and rats suffering from Ehrlich tumor and Zajdela's hepatoma, respectively, were centrifuged at 70,000 g and 200,000 g for 1 hour. Nucleic acid preparations were then isolated by phenol deproteinization and analysed by 8% polyacrylamide gel electrophoresis with subsequent densitometry. Under such conditions, DNA of nucleic factor as well as minor RNA fractions failed to precipitate. These results show that viral particles, tumor cell-produced vesicles and other large complexes do not incorporate DNA nucleic factor or minor RNA fractions.

Animals↗
PubMed1984

[The origin of 5 S DNA from tumor ascitic fluid].

Certain properties of DNA from chromatin mononucleosomes of the normal rat liver were compared with those of 5 S DNA from the ascitic fluids of human and animal tumours. Both DNA proved to be identical by their electrophoretic mobility in 8% PAAG and by characteristic violet tinge when stained with methylene blue. Thermal and alkaline denaturation causes less degradation of mononuclesome DNA than 5 S DNA. It is shown that 5 S DNA of ascitic fluid of Ehrlich ascite tumour of mice hybridizes with a higher amount of mouse genome DNA restricts. An assumption is advanced that 5 S DNA is either a product of chromatin decay to mononucleosomes or a product of extracopial synthesis and is delivered to ascitic fluid surrounding the tumour cells as a result of activation of Ca, Mg-dependent endonuclease of the latter.

Animals↗
PubMed1983

[High-molecular forms of DNA in the blood serum of rats with Zaidel's hepatoma].

Apart from heterogeneous high-molecular DNAs, two fractions corresponding to 17 and 20 MD of DNA and homogeneous with respect to mobility are to be found in preparations of nucleic acids of rat blood serum. The former fraction (17 Md) is greater than the latter in healthy animals. This ratio is reversed in the blood serum of rats with Zajdela's hepatoma. The relative predominance of 20 Md DNA is still more pronounced in ascitic liquid which washes tumor cells.

Animals↗