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Biomedical subjects

V A Shevchenko

Publications and source records attributed to V A Shevchenko.

105 records · Page 6Linked to original sources
PubMedDate not supplied

[The genetic consequences of the radioactive contamination of populations of Arabidopsis thaliana growing in a 30-kilometer area of the accident at the Chernobyl Atomic Electric Power Station].

Annually during six years since 1986 dynamics of the mutation load in Arabidopsis populations was studied. Frequency of the embryonic lethal mutations was studied with Muller embryonic test. First two years after the accident an increase of mutation load in Arabidopsis populations was observed at all levels of radioactive contamination. In the areas with contamination up to 10 mR/h the mutation load decreased to the control level by 1990. In the areas with contamination up to 130 mR/h the mutation load exceeds the control by 4-8 times.

Arabidopsis↗
PubMedDate not supplied

[The cytogenetic effects in natural populations of Crepis tectorum exposed to chronic irradiation in the region of the Chernobyl Atomic Electric Power Station. An analysis of the frequency of chromosome aberrations and karyotype changes in the 3rd and 4th years after the accident].

In three natural Crepis tectorum populations from 30-km zone of the Chernobyl NPP cytogenetic analysis of plant progenies was carried out. Germination capacity was not correlated with the dose rate of chronic irradiation. There was a correlation between frequency of cells with chromosome aberrations and frequency of seedlings with non-identical altered karyotype among which pericentric inversions and reciprocal translocations dominated. 9-chromosome altered karyotypes were found. Homozygous plants with altered karyotypes were not observed. Several heterozygous plants segregated homozygous seedlings with altered karyotype were found. In comparison with the second year after the accident in the third and fourth years there was stronger deviation from linear dependence between the cytogenetic effect and the dose rate of irradiation.

Alpha Particles↗
PubMedDate not supplied

[The genetic effect in Pinus sylvestris L. populations of the eastern Urals radioactive trace from the control area of the accident at the Chernobyl Atomic Electric Power Station and from the region of the nuclear device tests at the Semipalatinsk proving grounds].

The method of isoenzyme electrophoresis was used for comparative evaluation of genetical effects in populations of Pinus sylvestris L. growing in Kyshtym region (east Urals), the Chernobyl accident zone and in the region of Semipalatinsk nuclear tests (Altai). It was shown that mutation frequencies for allozyme loci are ranged as follows: Ural > Altai > Chernobyl.

Electrophoresis, Polyacrylamide Gel↗
PubMedDate not supplied

[The genetic processes in chronically irradiated natural populations of Centaurea scabiosa L. growing in the eastern Urals radioactive trace].

The examination of chronically irradiated natural populations of C. scabiosa L. have been carried out for 30 years at the territory of the east Urals radioactive trial. By using of different tests (frequency of aberrant cells, chlorophyll mutations and mutations in Lap locus) the mutation rates in chronically irradiated populations and in the control natural populations were compared. It was shown that long-term radiation influence caused changes in population genetic structure due to induction of new allelic forms and selection of more adapted genotypes.

Chlorophyll↗
PubMedDate not supplied

[The antimutagenic activity of ternary diallyl copolymers].

Antimutagenic activity of triple copolymers of diallyl origin was investigated by animal cell test (mouse bone marrow erythrocytes, 1.5 Gy of gamma irradiation) and by plant cell test (seeds of barley, 5 Gy of gamma irradiation). Effective protection of genetic structure was achieved owing to combination of moderate antimutagenic activity of the polymer matrix and scavenging ability of sterically hindered phenols in the polymer side chain.

Acrylates↗
PubMedDate not supplied

[The dose dependence of the induction of chromosome aberrations in those who worked in the cleanup of the Chernobyl accident].

The method of biological dosimetry based on registration of frequency of chromosome aberrations in peripheral lymphocytes was proven to be a valuable technique for estimation of large absorbed doses. In the case of low absorbed doses or low dose rate the suitability of this method is restricted because of deficiency of suitable dose-response curve for yield of chromosome aberrations. In this work chromosome aberration rate was estimated in 31 ameliorators of the Chernobyl accident with the known data of physical dosimetry in the range of 12-30 cGy. Linear dependence of induction of chromosome aberrations was found in this dose range. The coefficients for induction of dicentrics and all unstable aberrations of chromosome type was found to be 1.4 +/- 0.4 and 7.2 +/- 1.2 per 100 cells per 1 Gy, respectively.

Adult↗
PubMedDate not supplied

[Results of cytogenetic examination of participants in the decontamination after the accident at the Chernobyl nuclear power station, 5 years later].

Results of the cytogenetic investigation on the Chernobyl accident decontamination participants, 5 years after the accident, have been disclosed. Cytogenetic analysis was performed on circulating blood lymphocytes, using a standard cultivation technique. Differences were detected between control group and decontamination participants on frequency of aberrant cells and aberrations of chromosome type in peripheral blood lymphocytes. Maximal cytogenetic effect on this data was detected in persons, who had worked between May and August 1986. On the base of cytogenetic investigation data, the authors proposed to form high-risk groups, including oncologic risk groups, which need a profound dynamic investigation.

Accidents↗
PubMedDate not supplied

[An analysis of chromosome aberrations and SCE in children from radiation-contaminated regions of Ukraine].

About a two years later after the reactor accident in Chernobyl we carried out a three-year cytogenetical study of children, dwelling in two regions of Ukraine where the radiation fallout occurred. Chromosome analyses of these individuals have shown a significant increase of the frequency of aberrant cells and chromosomal type aberrations in comparison to the control. We have discovered the increase of the level of chromosomal type aberrations, extension in spectrum of complicate aberrations of chromosome (dicentrics, rings and exchange aberrations) with the years and the increase with the years a share of children with various chromosomal abnormalities. Analyses of sister chromatid exchanges (SCE) and a replication index (RI) show a significant increase of RI meaning with the years in comparison to the control. The SCE frequency didn't altered as compared to the control during different years of investigation.

Accidents, Occupational↗
PubMedDate not supplied

[The comparative radioresistance of chronically irradiated populations of Arabidopsis].

The radioresistance of seeds of populations of Arabidopsis thaliana (L.) Heynh. growing for 5 years in the regions with different levels of radioactive contamination within 30 km zone of Chernobyl NPP was studied. The analysis of comparative radiosensitivity by root test was performed. It has been shown that plants from Arabidopsis population growing under chronic irradiation did not gain an increased radioresistance. The data obtained show that they are more radiosensitive.

Accidents, Occupational↗
PubMedDate not supplied

[The genetic sequelae for plant populations of radioactive environmental pollution in connection with the Chernobyl accident].

Populations of Arabidopsis thaliana (L.) Heynh., and Pinus sylvestris L., growing within 30 km of Chernobyl and Bryansk region have been analyzed for the frequency of embryonic lethal mutations on Arabidopsis and frequency of chlorophyll mutations and chromosome aberrations by pine. On pine also have been analyzed rate of mutations at enzyme loci in endosperms of seeds. Dose dependence of the value genetic damage on level of radioactive pollution was observed.

Air Pollution, Radioactive↗
PubMedDate not supplied

[The characteristics of the biological action of low doses of irradiation].

Biochemical, biophysical and functional properties of the genetic and membrane apparatus of the cell were considered activity and regulatory properties of the membrane and cytosolic enzymes of organs and tissues of mice exposed to radiation in the wide range of doses of 6 to 1800 mGy with the radiation intensity of 4.1 x 10(-3) and 41 x 10(-3) mGy/min. It was shown that the dose-dependence of changes in the investigated properties is of non-linear polymodal (bimodal) nature. The value of the maximum and the dose at which the latter was observed depend on the object's nature, radiation intensity and time passed after irradiation. An essential factor is that sensitivity of molecules, cells, organs and animals exposed to low-dose radiation to other damaging effects changes. The explanation is given in terms of the changes in the relation between the quantity of damages and the activity of reparation systems induced by low-dose irradiation.

Animals↗
PubMedDate not supplied

[Modification of the mutagenic effects of gamma radiation by heavy metal salts].

The effect of K2Cr2O7 and (CH3COO)2Pb on the mutagenic activity of gamma rays was studied by a micronucleus test in mouse bone marrow polychromatocytes. Acute and chronic combined actions of the two factors were investigated. Chromium ions (VI) enhanced mutagenic effects of gamma rays in both acute and chronic experiments. In the acute experiments lead ions (II) below 15 mg/kg body weight decreased the number of gamma-ray-induced micronuclei, while higher doses increased it. Chronic combined action of lead ions (III) and gamma rays inhibited mutagenic activity of radiation.

Animals↗
PubMedDate not supplied

[Integral estimation of genetic effects of ionizing radiation].

A system of criteria (direct, indirect, extrapolational, integral, populational, evolutional) has been proposed to estimate the consequences of irradiation of flora, fauna and human population. This system makes it possible to obtain the most comprehensive estimate of genetic effects from exposure of live organisms to ionizing radiations. An attempt has been made to use extrapolational approaches for assessing the genetic risk on the basis of the results of cytogenetic examination of the human population in a number of regions exposed to the action of ionizing radiations as a result of the Chernobyl accident, in connection with the activity of the chemical plant Mayak in the Chelyabinsk region, nuclear explosions at the Semipalatinsk nuclear test site, the accident at the Three Mile Island nuclear power plant in the U.S.A.

Animals↗