[Inhomogeneity of control samples as the reason for additional variations in the spontaneous level of chromosome aberrations in a human lymphocyte culture]. / Neodnorodnost' kontrol'nykh vyborok kak prichina dopolnitel'nykh variatsii spontannogo urovnia khromosomnykh aberatsii v kul'ture limfotsitov cheloveka.

The results of population cytogenetic studies performed by a standard technique in one laboratory during 1987-1992 are summarized. Variations in the rate of spontaneous chromosomal aberrations were found in lymphocyte culture derived from individuals employed in the nonindustrial sphere and in the administrative sector of the chemical industry. The proportion of cells with chromosomal aberrations is 1.56 +/- 0.10% in the first group and 2.78 +/- 0.15% in the second one. The ratio of types of aberration is similar in both groups. No differences were observed in the rate of spontaneous chromosomal aberrations as related to the extent of chemical pollution of place of residence.

[Cytogenetic screening of workers of rubber manufacturing industry]. / Tsitogeneticheskoe obsledovanie rabochikh proizvodstva reziny.

Cytogenetic analysis of lymphocytes was performed in 36 preparatory workers engaged into rubber shoes and general mechanical rubber goods production. Preparatory workers and management staff had the same chromosomal aberrations frequency. Although chromosomal aberrations frequency in employees of the enterprise appeared to be twice as much as that for general population, which proves hazardous factors of rubber production to afflict genofond of employees.

[Cytogenetic examination of workers engaged in manufacturing of asbestos technical products]. / Tsitogeneticheskoe obsledovanie rabochikh proizvodstva asbesto-tekhnicheskikh izdelii.

The article contains data on a cytogenetic monitoring of workers engaged in asbestos production, depending on duration of professional service and degrees of dust contamination of the air. The results of the cytogenetic analysis of the peripheral blood lymphocytes in 31 workers revealed the average rate of aberrant cells 1.78% in workers with professional service below 1.5 years, 2.43%--with more than 10 years of service, 2.72%--in the control group (the personnel not engaged in the production). The differences were statistically negligible.

[Cytogenetic analysis of the peripheral blood lymphocytes in people residing in regions of the Kaluga Oblast polluted with radionuclides]. / Tsitogeneticheskii analiz limfotsitov perifericheskoi krovi u prozhivaiushchikh v zagriaznennykh radionuklidami raionakh Kaluzhskoi oblasti.

In order to reveal possible genetic effects of the Chernobyl accident for human populations, a cytogenetic survey of 33 agricultural workers from 2 areas of the Kaluga Region with different radiation backgrounds (villages of Mladensk and Ogor) was conducted in 1989. At the time of investigation a dose of 137Ce for Mladensk was 3.7 ci/km2, that for Ogor--1.17 ci/km2. Lymphocyte cultivation was performed after the standard semimicromethod for 50 hours; about 155-300 cells were analyzed for chromosome aberrations of each individual, the total number of metaphase plates in 2 groups being 9360. One-factor dispersion analysis has shown that the rate of exchanges of a chromosome type, specific for radiation, was higher in the workers of the village of Mladensk than in the workers of Ogor (p less than 0.05). Thus statistically significant differences in the rate of metabolic aberrations of a chromosome type were revealed in the two study groups with different radiation backgrounds. A high sensitivity of cytogenetic analysis for population biological indication of irradiation was shown.

[Relation between the dynamics of the cell cycle and the frequency of chromosome aberrations in cultured irradiated human lymphocytes]. / Vzaimosviaz' dinamiki kletochnykh tsiklov i chastoty khromosomnykh aberratsii v kul'ture obluchennykh limfotsitov cheloveka.

The method of differential staining of sister chromatids was used to study the dynamics of cell divisions at different periods of fixation (48, 56, 68, 80 h) of human lymphocyte cultures in control and after gamma-irradiation in vitro in doses of 150 and 300 rad. It is shown that the cell population of lymphocytes is extremely asynchronous by the time of first and subsequent cell divisions. Administration of gamma-rays before PHA stimulation results in a mitotic delay whose duration is proportional to the irradiation dose. The frequency of radiation-induced chromosome aberrations does not reliably differ in early- and late-dividing cells.

[Combined action of gamma irradiation and 5-bromodeoxyuridine on human chromosomes]. / Kombinirovannoe deistvie gamma-oblucheniia i 5-bromdezoksiuridina na khromosomy cheloveka.

A combined effect has been studied of 5-bromo-deoxyuridine (BDU) and gamma-radiation on human lymphocytes at the G0 stage. BDU is shown to induce chromatid aberrations irrespective of its radiation. The frequency of chromatid aberrations rises with the BDU concentration. BDU modifies the effect of gamma-radiation on human lymphocytes at the G0 stage, increasing the number of chromosome aberrations. BDU slows down the lymphocyte cell cycle.

[Statistical analysis of the elimination of chromosome-type aberrations and the fate of the aberrant cells]. / Statisticheskii analiz éliminatsii aberratsii khromosomnogo tipa i sud'by aberrantnykh kletok.

The regularities of elimination of gamma-ray induced chromosome aberrations in human nonstimulated lymphocytes and the fate of aberrant cells have been studied. The cells at the first, second and third post-irradiation divisions were identified by the technique of differential staining of sister chromatids. A mathematical model has been suggested to describe the processes of formation, multiplication and death of the cells with dicentrics. This model has been shown to be in a good agreement with the experimental data. According to the model, the distribution of dicentrics among cells at the first and second mitoses follows the Poisson distribution. The analysis of the model has shown that the probability of divergence of two chromatids from one dicentric chromosome is equal 1/2, and that the acentric and monocentric types of chromosome aberrations have no influence upon cell survival in vitro. A method for empirical estimation of survival of other types of aberrations has been suggested. According to these estimates, the probabilities of transmission to the next mitosis are equal 2/3, 1 and 1/3 for paired fragments, ring chromosomes and interstitial deletions, respectively. It has been shown that approximately 1/4 of survived acentric structures can diverge to both daughter cells.

[Frequency of sister chromatid exchanges in oncological patients during treatment with cyclophosphane]. / Chastota sestrinskikh khromatidnykh obmenov u onkologicheskikh bol'nykh v protsesse lecheniia tsiklofosfanom.

The sister chromatid exchange (SCE) level in patients with cancer of lungs before treatment did not differ from the mean number of SCE in healthy donors. In the process of a cyclophosphane treatment the SCE frequency in the patient lymphocyte culture increased with the drug doses of 4 and 5 g. Analysis of the ratio of cells in mitoses I, II and III revealed no differences in the cell cycle rate for groups of healthy donors, patients before the treatment, and treated patients.

[Sex differences in the secretory activity of the gonads and in their sensitivity to gonadotropins in early ontogenesis of rats]. / Polovye razlichiia sekretornoi aktivnosti gonad v chuvstvitel'nosti k gonadotropinam v rannem ontogeneze u krysy

The secretion of estrogens by the ovaries of foetal (15-19 days of gestation) and newborn rats in organ cultures was not detected by fluorimetry when the ovary was taken prior to the onset of folliculogenesis. The time schedule of the process of folliculogenesis in organ culture corresponded to that in vivo. Estrogens were detected in the medium when folliculogenesis was fully established in organ cultures. The secretion began spontaneously and was not affected by the addition of gonadotropins to the medium. On the contrary, the secretion of androgens by the testes of foetal (17-19 days of gestation) and newborn rats in organ cultures was constantly detected by the competitive protein-binding assay. The addition of gonadotropins to the culture medium increased the level of androgen secretion by foetal and newborn rats.

PIP: The influence of gonadotropins on the specific secretory activity of the gonads of rats was studied under cultivation. The ovaries and testicles were cultivated in rats from 15-day-old fetuses to newborn, over the course of 4-21 days with and without the addition of gonadotropins. Under these conditions the secretion of estrogens by the ovaries was detected only after the appearance of the 1st follicular cells. The addition of gonadotropins did not speed up this process, although it did increase the intensity of it to an insignificant degree. The secretion of the sex hormones in the testicles was observed at all phases of development studied (from the 17th day of the fetus until birth). The addition of gonadotropins intensified the secretion of androgens of the seminal glands throughout the entire period.