Biomedical subjects

B A Bogatykh

Publications and source records attributed to B A Bogatykh.

8 recordsLinked to original sources

PubMedDate not supplied

[Fractal structures in living beings and the evolutionary process ].

Fractal structures of living beings are discussed in the aspect of the directionality, i.e., programmed nature, of the evolutionary process. These theses are substantiated by analyzing the alternative views of Darwinism and Nomogenesis on the nature of biological evolution, in the context of the interdisciplinary approach, using the fractal concept, as well as based on the nature of the chaotic (fractal) attractors bearing non-random order-generating sequences. Apparently, along with the influence of natural selection representing the adaptive stage of evolution, the non-random order-generating sequences are the governing factor of the directionality and the programmed nature of biological evolution, thus representing its progressive form. A number of questionable and complicated problems and phenomena of the evolution of organic world that are difficult to explain by Darwinism, Nomogenetic theory, or by the Synthetic Theory of Evolution are discussed from this viewpoint. These are, in particluar, the nature of polymorphic series in plants and animals, M. Eigen's hypercycles, and Vavilov's homologous series in hereditary variation.

Animals↗

PubMedDate not supplied

[An analysis of the cytogenetic effects of gamma and neutron irradiation in a human lymphocyte culture at the G0 and G1 stages of the mitotic cycle (a structural-functional approach)].

A study was made of the dose dependence of the chromosome aberration frequency in human lymphocytes exposed to 60Co-gamma radiation and neutrons (mean energy of 0.85 MeV) at the G0 stage and in different periods of the G1 and G1/S stages of the cycle. With gamma irradiation the dose dependence for cells at the G1 and G1/S stages was at a higher level than that for cells at the G0 stage, whereas the opposite picture was observed for cells exposed to neutron radiation. The difference was also noted in the time-response curves where gamma radiation increased and neutrons, on the contrary, decreased the aberration yield in the cells that passed from G0 to G1 stage. The experimental data obtained are attributed to activation of repair system at the G1 stage which is mainly conditioned by chromatin decondensation; the activating, that is, the functional factor influences the aberration induction with gamma irradiation, while the decondensation, that is, the structural factor, with neutron irradiation.

Cells, Cultured↗

PubMedDate not supplied

[Cytogenetic effect of low-level 60Co gamma-irradiation of cultured human lymphocytes in the G1 phase of the mitotic cycle].

The dose-dependence of the chromosome aberration frequency in human lymphocytes in vitro exposed to 60Co-gamma-radiation at the G1 stage of the mitotic cycle has proved to be unlike that obtained upon exposure of cells at the G0 stage of the cycle. The data obtained are accounted for by partial activation of the repair system at the G1 stage which is attributed mainly to chromatin decondensation.

Cells, Cultured↗

PubMedDate not supplied

[Effect of interferon on the yield of chromosome aberrations in cultured human lymphocytes irradiated with fast neutrons].

A study was made of the influence of leucocytic interferon on the yield of chromosome aberrations in a human lymphocyte culture after irradiation of cells with fast neutrons (0.85 MeV) at the G0- and G1-stages. It was shown that in cells treated with interferon (50 UE/ml) prior to irradiation the total yield of aberrations and of some of their types was invariable as compared to the irradiated control.

Cell Cycle↗

PubMedDate not supplied

[Formation of chromosome aberrations at different stages of the mitotic cycle in a culture of human lymphocytes irradiated with neutrons of average energy 0.35 and 0.85 MeV].

Incidence of chromosome aberrations at different mitotic cycle stages of a human lymphocyte culture has been studied after exposure to 60Co-gamma-quanta (2 Gy) and neutrons of 0.85 Mev (1 Gy) and 0.35 MeV (0.5 Gy). The yield of chromosome aberrations with both gamma- and neutron-radiation depends on a stage of the mitotic cycle. The S stage is the most radioresistant one with both types of ionizing radiation.

Chromosome Aberrations↗

PubMedDate not supplied

[Effect of the time before fixation on the yield of chromosome aberrations in a culture of human lymphocytes exposed to gamma rays at different stages of the mitotic cycle].

A comparative study was made of the yield of chromosome aberrations in human lymphocyte culture exposed to 60Co-gamma-rays (2 Gy) at different mitotic cycle stages the cells being fixed after 52 and 60 hr. It was shown that with the latter fixation time (60 hr) the frequency of chromosome aberrations after irradiation in G1 stage was substantially lower than that with the former one (52 hr) and, vice versa, it was higher after irradiation in S and G2 stages. The authors discuss the probable causes of the distinctions observed.

Chromosome Aberrations↗

PubMedDate not supplied

[The effect of inhibitors of DNA and protein synthesis on the chromosome aberration yield in a human lymphocyte culture exposed to gamma and neutron irradiation at different stages of the mitotic cycle. The cytogenetic effects in the G0 phase].

The effect of inhibitors of protein synthesis, cycloheximide (CH), and DNA synthesis, hydroxyurea (OU) in combination with 5-fluoro-2-deoxyuridine (OU + FDUR), on the yield of chromosome aberrations in cultured human lymphocytes induced by gamma- and neutron irradiation with doses of 1 and 2 Gy in G0 phase of mitotic cycle has been studied. The inhibitors added immediately after gamma-irradiation have caused reliable increase of aberration rate (CH at both doses and OU + FDUR at a dose of 2 Gy only). Both inhibitors caused no effect being added after 1.5, 3 and 5 hr after gamma-irradiation. The chromosome aberration rate substantially increased at both doses of neutron irradiation for both inhibitors added at all studied time intervals after exposure. Chromosome exchange aberrations have most contributed to the increase of aberration rate.

Blood Proteins↗

PubMedDate not supplied

[The comparative radiosensitivity of the lymphocytes of men and women under gamma irradiation at the G0 stage of the mitotic cycle].

Radiosensitivity of male and female lymphocytes exposed to gamma radiation (60Co) in phase G0 of the mitotic cycle has been comparatively studied. The radiosensitivity was shown to be identical, within the limits of error, although with the recombination repair (the nonhomologous nature of X and Y chromosomes being taken into account) the number of chromosome aberrations in male cells must be 1.4 times larger than in female cells. This indicates an absence or (within the limits of error) an insignificant role of the recombination repair of double-strand DNA breaks.

Adult↗