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A V Sevan'kaev

Publications and source records attributed to A V Sevan'kaev.

At least 19 recordsLinked to original sources
PubMed2004

A cytogenetic follow-up of some highly irradiated victims of the Chernobyl accident.

A follow-up of 10 highly irradiated men, mostly reactor crew, from the Chernobyl accident is described. Their pre-accident medical conditions and relevant medical status approximately 10-13 y later are listed. A comparison is made between estimates of their average whole-body penetrating radiation doses derived from several biological parameters. First estimates were based on their presenting severity of prodromal sickness, early changes in blood cell counts and dicentric chromosome aberrations in lymphocytes. In three cases ESR measurements on tooth enamel were also made. Retrospective dosimetry using FISH translocations was attempted 10-13 y later. This showed good agreement for those patients with the lower earlier dose estimates, up to about 3 Gy. For the others, extending up to about 12 Gy, the translocations indicated lower values, suggesting that in these cases translocations had somewhat declined. Repeated chromosomal examinations during the follow-up period showed an expected decline in dicentric frequencies. The pattern of decline was bi-phasic with a more rapid first phase, with a half-life of approximately 4 months followed by a slower decline with half-lives around 2-4 y. The rapid phase persisted for a longer time in those patients who had received the highest doses. 10-13 y later dicentric levels were still above normal background, but well below the translocation frequencies.

Adult↗
PubMed2002

Cytogenic investigations of serious overexposures to an industrial gamma radiography source.

This paper describes the sequence of events, medical aspects and dose estimations for two radiographers and their driver who were seriously exposed to an iridium-192 industrial radiography source that became detached from its wind-out cable. The men came to medical attention about 1 month later by which time all three were severely leucopenic and one had skin burns on both hands. Doses were estimated by (i) physics calculations combined with their accounts of the event. (ii) the levels of depression of their blood neutrophils, (iii) electron spin resonance on tooth enamel and (iv) blood lymphocyte chromosomal analyses by the conventional dicentric and the fluorescence in situ hybridisation methods. Intercomparison of these methods for estimating doses showed a good level of agreement. In brief, the averaged whole body dose for the most seriously exposed man was about 2.5-3.0 Gy and for the others it was 1.0-2.0 Gy.

Acute Disease↗
PubMed2000

Novel data set for retrospective biodosimetry using both conventional and FISH chromosome analysis after high accidental overexposure.

Blood samples of ten Chernobyl and one non-Chernobyl victims were analysed both by conventional cytogenetics and by fluorescence in situ hybridization (FISH) using a cocktail of chromosomes 2, 3 and 8. The analysed group comprised men acutely irradiated mainly in 1986 and aged 26-47 years at the time of first blood sampling. All of them displayed acute radiation syndrome of varying severity. Chromosome analysis of the earliest blood samples was carried out by conventional scoring of unstable aberrations with the number of metaphases analysed per individual ranging from 35 to 300. Estimated individual doses ranged from 0.85 to 9.8 G y. After a 10 year delay, i.e. in 1996, blood samples were analysed both by conventional scoring of unstable aberrations and by FISH measurements of stable ones. Usually about 500 metaphases per individual were scored. Estimated by the FISH-method individual translocation (tc + ti) frequencies ranged from 2.2 to 116.8 per 100 cells full genome equivalent. Based on three different published dicentric dose response, in vitro curves individual doses were calculated from the earliest dicentric frequencies. A dose response curve for truly persisting translocations (tc + ti) was estimated over the range 1-10 Gy.

Adult↗
PubMed1997

Unstable and stable chromosomal aberrations in lymphocytes of people exposed to Chernobyl fallout in Bryansk, Russia.

Analyses of unstable and stable chromosomal aberrations in peripheral blood lymphocytes were used in the assessment of radiation exposure of residents of a village situated in the Chernobyl fallout-contamination zone of Bryansk, Russia. Blood samples were taken from subjects residing in villages with high (> 1100 kBq/m2 137 Cs; Mirnyi) and very low (< 37 kBq/m2 137 Cs; Krasnyi Rog) contamination, 7 years after the Chernobyl accident. The groups were matched by age, sex, smoking habits and previous medical radiological exposures. A total of 200 people (100 exposed, 100 controls) were analysed for the presence of unstable aberrations from Giemsa-stained slides. To study stable aberrations, chromosome painting analyses were performed on 100 subjects (50 exposed, 50 controls), using painting probes for chromosomes 1, 2 and 4 and a pancentromeric probe. People living in the contaminated area showed significantly higher rates of unstable chromosome-type aberrations but not chromatid-type aberrations in their lymphocytes, indicating radiation exposure as a causative factor for the observed difference. No significant differences were found in the aberration rates between the two areas by the chromosome painting method. The levels of chromosome exchanges were low in both populations, but consistently higher in Mirnyi compared with the control area. The magnitude of radiation exposure resulting from Chernobyl fallout was estimated on the basis of excess stable chromosomal aberrations in the lymphocytes of the Mirnyi population compared with the controls.

Adult↗
PubMed1993

'Rogue' cells observed in children exposed to radiation from the Chernobyl accident.

Eight 'rogue' lymphocyte metaphases containing a large number of aberrant chromosomes were noted during a survey of chromosomal damage in 328 Belarussian children. The study population comprised children of families living in territory contaminated by radiation from the Chernobyl accident. The majority of the sample had been evacuated within 1 week from very heavily polluted territory to areas that had received much less fallout. Two hundred cells were scored per subject and one rogue cell was found in a child exposed in utero; one in a child conceived after the accident and six in the postnatally exposed group. The possibility that the damage was due to exposure to radio-iodine concentrated in the thyroid gland, or to radiation from incorporated 'hot particles' of an alpha or beta/gamma emitter is discussed. It is concluded that the damage to these cells is unlikely to have been caused by radiation.

Accidents↗
PubMed1990

[Around the Semipalatinsk proving grounds: the radioecological situation and the population radiation doses in Semipalatinsk Province (based on data from the report of the Interdepartmental Commission)].

The paper represents some results of a joint commission, organized by the USSR Ministry of Health by order of the USSR Council of Ministers at public requests. The commission worked in the area neighbouring the proving ground at Semipalatinsk in the period of May-July 1988. A radiological situation there was investigated after underground nuclear testing on July 8, 1989. The results of measurements and archive data were used to estimate doses of radiation exposure of the population in the period of 1949 (nuclear testing on the ground and in the atmosphere) and in the period of underground testing, It was shown that in the period of 1949-1963 approximately 10,000 people received increased doses of external and internal irradiation. A high level of radiation-induced chromosome aberrations was noted among them. The highest effective equivalent doses of external and internal irradiation were received by the residents in the villages of Folon' (1.6 Gy during the first testing in 1949), Karaul (0.37 Gy), Sarzhal (0.20 Gy), Semenovka (0.02 Gy). The annual effective equivalent doses at that period did not exceed 0.0056 Gy (the highest value) for the Semipalatinsk residents. Proceeding from the values of collective doses probable long-term effects (malignant tumors) were assessed. Recommendations and conclusions of the commission are presented.

Ecology↗
PubMed1989

[Effect of hyperthermia on the yield of chromosome aberrations during the irradiation of human G1-stage lymphocytes with 252Cf and 60Co sources of various dosage intensities].

A study was made of the regularities of structural chromosome damages in human peripheral blood lymphocytes during irradiation at the G1 stage with 252Cf and 60Co sources in dose rates of 0.035 and 0.35 Gy/min at doses of 0.27-3.1 Gy. In 252Cf radiation, the frequency of chromosome aberrations at the G1 stage was described by linear dose-effect ratio in both dose rates and did not depend on a dose rate in the studied dose range. The RBE of 252Cf radiation at the G1 stage grew with a decrease in a dose and dose rate. Postradiation hyperthermia caused less noticeable enhancement of the effect of 252Cf radiation (approximately 10%) as compared to that of 60Co radiation (approximately 30%).

Californium↗
PubMed1989

[Influence of the dose rate and postradiation hyperthermia on the cytogenetic effect of irradiation of cells in the G0 stage by 252Cf and 60Co sources].

The paper is concerned with the results of a comparative study of radiation injury of chromosomes of human lymphocytes at the G0 stage resulting from the influence of 60Co gamma quanta and high activity 252Cf radiation sources and depending on a dose and dose rate; with the potentialities of modifying a cytogenetic effect of irradiation by postradiation hyperthermia of cells. It has been shown that at the G0 stage of a cell cycle the frequency of chromosome aberrations does not depend on the dose rate of 252Cf radiation within the range of 0.0035-0.35 Gy/min. by the neutron component. Linear correlation between the frequency of induced chromosome aberrations and a dose was observed within a dose range of 0.27-3.1 Gy. Thus, a conclusion is that postradiation hyperthermia at the G0 stage does not almost influence the frequency of chromosome aberrations during 252Cf radiation, and increases it insignificantly during 60Co gamma-radiation.

Adult↗
PubMed1981

[Effect of gamma irradiation on human chromosomes in vitro. IX. The ratio of the yield of aberrations to the time of cell fixation in GO-stage irradiation].

The dependence of the chromosome aberration yields on the sampling time was studied in the culture of human lymphocytes after different doses of gamma-irradiation in the stage G0. It was shown that the cells irradiated in the stage G0 had the constant aberration frequency during the first division after irradiation (45 to 55 hours). The distribution of aberrations among the cells examined at first division was poisson. These results are interpreted in favour of homogeneous chromosomal radiosensitivity of the population of PHA-responsive lymphocytes.

Cells, Cultured↗
PubMed1979

[Cytogenetic effects induced by neutrons in human peripheral blood lymphocytes in vitro. I. Dose-effect relationship for different types of chromosome aberrations when exposed to neutrons with different energies].

Human lymphocytes were irradiated in vitro during G0 stage by graded doses of thermal neutrons and of neutrons with mean energy of 0.04; 0.09; 0.35; 0.85 and 14.7 MeV as well as by 60Co gamma-rays. The data were fitted to the linear and linear-quadratic relations. The neutrons of low and intermediate energies showed the linear dependence on the dose, 14.7 MeV neutrons and gamma-rays--a linear-quadratic one, whereas the data obtained with 0.85 MeV neutrons fitted well the both models. Terminal and interstitial deletions produced by both gamma-rays and neutrons showed different dependencies upon the dose. Some qualitative pecularities of aberration spectra were found in the experiments with neutrons as compared with the data on gamma-irradiation: the ratio of exchanges to fragments was greater, and aberrations of chromatid type were produced. The specially designed experiments and calculations showed that the last effect was not connected with induced radioactivity.

Cells, Cultured↗
PubMed1979

[Cytogenetic effects induced in vitro in human peripheral blood lymphocytes by neutrons. II. Relative biological effectiveness of neutrons having different energies].

Human lymphocytes were irradiated in vitro during Go stage by graded doses of thermal neutrons and neutrons having an average energy of 0.04; 0.09; 0.35; 0.85 and 14,7 MeV as well as by 60Co gamma rays, and RBE of neutrons relative to gamma-rays was calculated for the frequency of total and different types of aberrations. It was found that the RBE has the most value at the low doses and decreases when the exposition dose increases. 0.35 MeV neutrons have the maximum RBE in comparison with neutrons having other energies. When comparing the RBE values calculated for different types of chromosome aberrations, it was found out that dicentrics and dicentrics plus centric rings had more RBE than acentric aberrations (pair fragments and minutes).

Chromosomes, Human↗
PubMed1977

[Effect of gamma-irradiation on human chromosomes. VIII. Cytogenetic effect of low doses during in vitro irradiation].

Cultures of human lymphocytes obtained from blood of healthy adult donors were irradiated at different doses of gamma-rays (60Co), and irradiated cells were analysed at metaphase in 50 hours after the irradiation. The effect (total yield of aberrations of chromosome type, or total yield of exchange type aberrations) produced by the lowest dose (5 r) appears to be statistically significant in a sample of 1500 cells. Within usual dose-range (25--400 r) both parabolic and linear-quadratic equations give a satisfactory fit of experimental data (dicentrics, fragments, or all aberration of the chromosome type). Low doses of gamma-rays produce, however, more aberrations than expected, if one extrapolates dose-effect curves from higher doses. Both equations should be considered therefore just as empirical equations. Dicentrics show a plateau at low doses (10--30 r) which appear to be statistically significant. Some indications are obtained that the total number of chromosome-type aberrations is a more reliable criterion of cytogenetic damage than usually accepted yield of dicentrics and rings.

Cells, Cultured↗