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Biomedical subjects

V A Shevchenko

Publications and source records attributed to V A Shevchenko.

At least 37 records · Page 2Linked to original sources
PubMed1992

The structure of Dreissena polymorpha populations from basins adjacent to the Chernobyl atomic power station.

The genetic and morphological differences among seven Dreissena polymorpha populations exposed to various environmental factors in the water basins adjacent to the Chernobyl atomic power station were examined. All of the populations showed differences in gene frequencies at four polymorphic loci. The populations could be divided into two groups according to temperature regime at the breeding site. Differences in Dreissena polymorpha populations were observed largely for those loci that showed significant deviations from the Hardy-Weinberg distribution. Radiation failed to cause any significant effect on the population structure. Within the limits considered, diversity in shell coloration among Dreissena polymorpha populations was governed by conditions at the breeding site (character of the substrate, rate of water flow, etc.), and not by thermal or radioactive contamination.

Accidents↗
PubMed1991

[Postextrasystolic potential in patients with a left ventricular postinfarct aneurysm].

The author analyzes the effect of postextrasystolic potentiation of contraction of the asynergic regions of the myocardium in 18 of 34 patients with postinfarction aneurysm of the left ventricle evaluated by contrast ventriculography. There was a statistically valid increase of the extension of the zones of hypokinesia due to reduction of the relative length of akinetic regions as compared with data of control contractions, a significant rise of reduction of the sizes of hypokinetic zones, increase of the fraction of ejection of the contractile segment in the general fraction of ejection. It is recommended to use the effect of postextrasystolic potentiation of contraction on the function of asynergic regions of the myocardium with the purpose of assessment of their vitality, determination of resection borders and expediency of their revascularization in the course of aneurysmectomy.

Adult↗
PubMed1990

[The treatment of hypertension patients with neurological disorders].

The authors describe the efficiency of complex treatment of patients suffering of hypertensive disease with phenomena of dyscirculatory encephalopathy. It is concluded that cavinton and pyracetam depending on the type of central hemodynamics and type of vegetative nervous activity proved effective.

Adrenergic beta-Antagonists↗
PubMed1990

Repair of radiation induced DNA damages in unicellular green algae.

Two cell repair systems--photoreactivation and repair of single-strand DNA breaks have been studied using unicellular green algae as a test-system. Effects of the genotype and the intensity of pico/second UV-laser irradiation on the degree of the photoreactivation have been investigated. It has been shown that the lower intensity (I = 8.10(6) W/cm2) effects less the inactivation of living cells comparing with I = 30.10(6) W/cm2, regardless of the genotype. The clearly expressed higher potentials of strains LARG-1 and 260 to produce and repair alterations of the cyclobutane-pyrimidine dimers type have been established. An analysis of DNA degradation during gamma rays irradiation and after incubation has been carried out for investigation the relationship between strains radioresistance and repair of single-strand break. It has been shown that high efficiency of the repair system is characteristic of the resistant strain obtained from chronically irradiated population.

Chlorella↗
PubMed1990

[Genetic effects in mice exposed to the 10-km area around the Chernobyl Atomic Energy Station].

Mice (CBAxC57BL) F of both sexes were exposed within the 10 km zone of Chernobyl nuclear power station. Genetic damage of phone chronic effect of increased radiation in exposed adult mice and in the course of embryogenesis was studied. The total absorbed radiation doses in testes varied from 1.85 to 0.42 Gy in embryos and from 3.4 to 2.7 Gy in adult males. Increase of dominant lethal mutations (DLM) and abnormal sperm heads (ASH) was only observed right after the end of exposure of adult males. The yield of reciprocal translocations (RT) in these males was relatively low. Among the males exposed at the stage of early embryogenesis, 4 heterozygotes for RT were revealed. In other males of this group the RT yield was low.

Animals↗
PubMed1990

[Genetic damage in domestic mice inhabiting in the areas with elevated background radiation].

Genetic effects of irradiation in males of wild house mice which were caught in the region of Chernobyl Nuclear Power Station were studied. The dose rate on the ground surface varied from 0.04 to 200 mR/h of gamma-irradiation. The increasing yield of dominant lethal mutations was only observed in males from the most contaminated sector. Reciprocal translocations were observed in spermatocytes of mice at all the levels of contamination. The rate of reciprocal translocations was relatively low and increased linearly with the elevation of the dose rate. The extent of testis damages increased also, as the dose rate grew. The frequency of abnormal sperm heads, the yield of recessive lethal mutations, litter size and radiosensitivity of the first progeny were not changed, depending on the dose rate.

Accidents↗
PubMed1989

Genetic effects of 131I in reproductive cells of male mice.

A study was made of the frequencies of dominant lethal mutations (DLM) in pre- and post-meiotic germ cells, reciprocal translocations (RT) in spermatogonia and abnormal sperm heads (ASH) induced by a single intraperitoneal administration of Na131I with an activity of 1.48-740 kBq/g to male mice. The frequency of DLM was shown to increase only when postmeiotic cells were exposed to the radionuclide. The RT frequency increased insignificantly with increases in the dose of 131I. The ASH frequency increased only when maximal doses of 131I were administered. The relative biological efficiency (RBE) of 131I with reference to the indices under study is less than 1.

Animals↗
PubMed1989

Evaluation of the genetic effects of 238Pu incorporated into mice.

The genetic effects of 238Pu incorporated into male mice were estimated by several tests. The activity of the administered 238Pu nitrate varied from 7 to 1850 Bq/g of body weight. The average alpha-radiation dose absorbed in the testes ranged from 2 to 96 cGy, with a dose rate of 0.004-1 cGy/day. alpha-Radiation from 238Pu was shown to induce dominant lethal mutations (DLM) and reciprocal translocation (RT), chromosomal fragmentation and formation of abnormal sperm heads (ASH). The effect does not depend on the average alpha-radiation dose absorbed in the testis. The relative genetic efficiency of alpha-radiation, as compared with that of chronic alpha-radiation for the indices under study, was about 10-20.

Alpha Particles↗
PubMed1988

[Evaluation of genetic consequences of 238Pu incorporation into mammals].

The genetic effects of gonadal burdens of 238Pu after single injection were studied in male mice. The activity of plutonium was 7 to 1850 Bk/g. The average doses of accumulated alpha-particles in testis varied from 2 to 96 Gy.10(-2), the dose rate being 0.004 to 1 Gy.10(-2) per day. The genetic end points are: the dominant lethal mutation rate; the frequency of reciprocal translocations; the recessive lethal mutation rate and frequency of abnormal sperm head morphology. For all tests used, no linear dependence of the effect on the alpha-dose was observed. The RBE value of alpha-irradiation was 10-20 relative to chronic gamma-irradiation.

Alpha Particles↗
PubMed1986

Chromosome aberrations in F1 from irradiated male mice studied by their synaptonemal complexes.

Possible implications of surface-spread synaptonemal complex (SC) karyotyping in analysing the causes of sterility of F1 from irradiated male mice are demonstrated in this work. After irradiation by 137Cs gamma-rays at a dose of 5 Gy the males were mated to unirradiated females and genetic analysis of fertility in the F1 progeny was carried out. Males with abnormal fertility were examined for the presence of chromosome aberrations in diakinesis-metaphase I and in pachytene by the method of surface-spread SC karyotyping. In most cases, SC karyotyping provides additional information and permits the detection and analysis of aberrations that are not revealed in diakinesis. Two reciprocal translocations, one X autosomal and one nonreciprocal translocation were discovered in five F1 males studied. It is concluded that the method is efficient in detecting translocations in pachytene in partially fertile F1 hybrids of irradiated and normal mice.

Animals↗