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A N Chebotarev

Publications and source records attributed to A N Chebotarev.

82 records · Page 5Linked to original sources
PubMedDate not supplied

[Comparison of the level of sister chromatid exchanges and chromosome aberrations induced by chemical mutagens in vitro and in vivo].

The paper presents results of a study of a dose dependence of induction of SCE and chromosomal aberrations at the exposure of human lymphocytes in vitro and bone marrow cells of mice in vivo to 5 alkylating chemicals. The efficiency of SCE induction in vitro is found to be 300-30 times as high as that of arising of chromosomal aberrations. The same regularity is observed in experiments in vivo, but the ratio is reduced to 60-20 times.

Animals↗
PubMedDate not supplied

[Quantitative evaluation of the effectiveness of the formation of sister chromatid exchanges and chromosome aberrations as affected by chemical mutagens].

Dose curves of five chemicals were studied to compare the efficiency of SCE and chromosomal aberration induction by different chemical mutagens. SCEs were found to increase linearly with the dose, whereas chromosomal aberrations--nonlinearly. Using regression coefficients obtained from the dose curves it was found that the efficiency of the studied chemical mutagens in induction of SCEs is 100-300 times as high as that in the induction of chromosomal aberrations.

Cells, Cultured↗
PubMedDate not supplied

[Comparative effectiveness in the induction of sister chromatid exchanges and chromosome aberrations].

The dose curves for 5 chemicals were studied to compare the efficiency of induction of SCEs and chromosomal aberrations by "polycentric" mutagens. The number of SCEs was found to increase linearly with the dose while that of chromosomal aberrations--nonlinearly. The efficiency of SCEs induction by these mutagens was found to be 25-50 times as high as in the induction of chromosomal aberrations. Division of alkylating mutagens into "monocentric" and "polycentric" is shown to be useful. It reflects their different efficiency in damaging one or simultaneously two DNA strands. The correlation between SCEs and formation of aberrations of the chromatid type is stated.

Cells, Cultured↗
PubMedDate not supplied

[Decrease in the spontaneous frequency level of sister chromatid exchanges in cell division in culture].

The spontaneous level of sister chromatide exchanges (SCE) registered in human lymphocytes is shown to depend on the moment of BUdR introduction and the time of fixation. In early periods of BUdR introduction and fixation the general spontaneous level of SCE may be observed and in later periods only that part of SCE may be registered which is caused by internal conditions. The difference between the first and second results makes the part of SCE conditioned by the environmental effects.

Adult↗
PubMedDate not supplied

[Frequency of mutagen-induced sister chromatid exchanges in the course of 3 cell cycles].

The induction of SCE by fotrine (0.125 and 0.250 microgram/ml) and thiophosphamide (5 micrograms/ml) during the first three cell cycles was studied in the Chinese hamster cells. No increase in the SCE number was observed after treatment with thiophosphamide and fotrine at the G2 stage (the first stage from the moment of fixation) as compared with the control variants. The maximal sensitivity of the cells to the SCE induction by the mutagens is marked at the G1 stage of the first cell cycle before the moment of fixation. The level of SCE remains approximately the same in the second cell cycle before the moment of fixation (20-32 h) and decreased down to the control level at the G1 stage of the third cell cycle (48-52 h).

Alkylating Agents↗
PubMedDate not supplied

[Comparative effectiveness of sister chromatid exchange induction with ethyleneimine derivatives in a human lymphocyte culture].

The efficiency of SCE induction by six ethylene imine derivatives has been studied in the culture of human lymphocytes. It is found that there is a linear relation between SCE and a dose, irrespective of the number of functional groups and their distribution in the molecule. Hexamethyl triamid which has no functional ethylene imine groups does not induce SCE. The monocentric agents are more active than bicentric ones. A linear increase of SCE induced by a monofunctional agent does not agree with Shafer's bypass model.

Aziridines↗
PubMedDate not supplied

[Expression of lysosomal enzymes in pregnancy].

Activities of 6 lysosomal enzymes in leukocytes and 3 enzymes in blood serum were studied in pregnant women. Only activity of beta-D-glucosidase was not altered within all the pregnancy of I-III trimesters, while activity of all the other enzymes studied was distinctly increased to the third trimester. Use of the data obtained in prenatal diagnosis of lysosomal storage diseases is discussed.

Enzymes↗
PubMedDate not supplied

[Use of 5-bromodeoxyuridine for determining the duration of cell cycle phases].

The method of differential staining of sister chromatids by means of 5-bromdesoxyuridine (BDU) was used to determine duration of the cellular cycle and its phases in a cell culture of Chinese hamster. The mitotic cycle lasted for 16 hrs, G1 for 5 hrs, S for 8 hrs and G2 for 3 hrs. These values do not differ from those obtained by the autoradiography. The given method permits quicker determination of the cellular cycle phases duration as compared with the autoradiography method.

Animals↗